WorldWideScience

Sample records for single red giants

  1. Red giants seismology

    Science.gov (United States)

    Mosser, B.; Samadi, R.; Belkacem, K.

    2013-11-01

    The space-borne missions CoRoT and Kepler are indiscreet. With their asteroseismic programs, they tell us what is hidden deep inside the stars. Waves excited just below the stellar surface travel throughout the stellar interior and unveil many secrets: how old is the star, how big, how massive, how fast (or slow) its core is dancing. This paper intends to paparazze the red giants according to the seismic pictures we have from their interiors.

  2. Red giants: then and now

    Science.gov (United States)

    Faulkner, John

    Fred Hoyle's work on the structure and evolution of red giants, particularly his pathbreaking contribution with Martin Schwarzschild (Hoyle and Schwarzschild 1955), is both lauded and critically assessed. In his later lectures and work with students in the early 1960s, Hoyle presented more physical ways of understanding some of the approximations used, and results obtained, in that seminal paper. Although later ideas by other investigators will be touched upon, Hoyle's viewpoint - that low-mass red giants are essentially white dwarfs with a serious mass-storage problem - is still extremely fruitful. Over the years, I have further developed his method of attack. Relatively recently, I have been able to deepen and broaden the approach, finally extending the theory to provide a unifying treatment of the structure of low-mass stars from the main sequence though both the red-giant and horizontal-branch phases of evolution. Many aspects of these stars that had remained puzzling, even mysterious, for decades have now fallen into place, and some questions have been answered that were not even posed before. With low-mass red giants as the simplest example, this recent work emphasizes that stars, in general, may have at least two distinct but very important centres: (I) a geometrical centre, and (II) a separate nuclear centre, residing in a shell outside a zero-luminosity dense core for example. This two-centre perspective leads to an explicit, analytical, asymptotic theory of low-mass red-giant structure. It enables one to appreciate that the problem of understanding why such stars become red giants is one of anticipating a remarkable yet natural structural bifurcation that occurs in them. This bifurcation occurs because of a combination of known and understandable facts just summarized namely that, following central hydrogen exhaustion, a thin nuclear-burning shell does develop outside a more-or-less dense core. In the resulting theory, both ρsh/ρolinec and

  3. High-resolution Spectroscopic Observations of Single Red Giants in Three Open Clusters: NGC 2360, NGC 3680, and NGC 5822

    Science.gov (United States)

    Peña Suárez, V. J.; Sales Silva, J. V.; Katime Santrich, O. J.; Drake, N. A.; Pereira, C. B.

    2018-02-01

    Single stars in open clusters with known distances are important targets in constraining the nucleosynthesis process since their ages and luminosities are also known. In this work, we analyze a sample of 29 single red giants of the open clusters NGC 2360, NGC 3680, and NGC 5822 using high-resolution spectroscopy. We obtained atmospheric parameters, abundances of the elements C, N, O, Na, Mg, Al, Ca, Si, Ti, Ni, Cr, Y, Zr, La, Ce, and Nd, as well as radial and rotational velocities. We employed the local thermodynamic equilibrium atmospheric models of Kurucz and the spectral analysis code MOOG. Rotational velocities and light-element abundances were derived using spectral synthesis. Based on our analysis of the single red giants in these three open clusters, we could compare, for the first time, their abundance pattern with that of the binary stars of the same clusters previously studied. Our results show that the abundances of both single and binary stars of the open clusters NGC 2360, NGC 3680, and NGC 5822 do not have significant differences. For the elements created by the s-process, we observed that the open clusters NGC 2360, NGC 3680, and NGC 5822 also follow the trend already raised in the literature that young clusters have higher s-process element abundances than older clusters. Finally, we observed that the three clusters of our sample exhibit a trend in the [Y/Mg]-age relation, which may indicate the ability of the [Y/Mg] ratio to be used as a clock for the giants. Based on the observations made with the 2.2 m telescope at the European Southern Observatory (La Silla, Chile) under an agreement with Observatório Nacional and under an agreement between Observatório Nacional and Max-Planck Institute für Astronomie.

  4. From red giants to planetary nebulae

    International Nuclear Information System (INIS)

    Kwok, S.

    1982-01-01

    The transition from red giants to planetary nebulae is studied by comparing the spectral characteristics of red giant envelopes and planetary nebulae. Observational and theoretical evidence both suggest that remnants of red giant envelopes may still be present in planetary nebula systems and should have significant effects on their formation. The dynamical effects of the interaction of stellar winds from central stars of planetary nebulae with the remnant red giant envelopes are evaluated and the mechanism found to be capable of producing the observed masses and momenta of planetary nebulae. The observed mass-radii relation of planetary nebulae may also be best explained by the interacting winds model. The possibility that red giant mass loss, and therefore the production of planetary nebulae, is different between Population I and II systems is also discussed

  5. Nitrogen depletion in field red giants

    DEFF Research Database (Denmark)

    Masseron, T.; Lagarde, N.; Miglio, A.

    2017-01-01

    , the behaviour of nitrogen data along the evolution confirms the existence of non-canonical extramixing on the red giant branch (RGB) for all low-mass stars in the field. But more surprisingly, the data indicate that nitrogen has been depleted between the RGB tip and the red clump. This may suggest that some...

  6. Kepler Asteroseismology of Red-giant Stars

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J.

    2012-01-01

    The Kepler mission, launched in March 2009, has revolutionized asteroseismology, providing detailed observations of thousands of stars. This has allowed in-depth analyses of stars ranging from compact hot subdwarfs to red giants, and including the detection of solar-like oscillations in hundreds ...

  7. Asteroseismic Diagram for Subgiants and Red Giants

    Energy Technology Data Exchange (ETDEWEB)

    Gai, Ning; Tang, Yanke [College of Physics and Electronic information, Dezhou University, Dezhou 253023 (China); Yu, Peng [College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331 (China); Dou, Xianghua, E-mail: ning_gai@163.com, E-mail: tyk450@163.com [Shandong Provincial Key Laboratory of Biophysics, Dezhou University, Dezhou 253023 (China)

    2017-02-10

    Asteroseismology is a powerful tool for constraining stellar parameters. NASA’s Kepler mission is providing individual eigenfrequencies for a huge number of stars, including thousands of red giants. Besides the frequencies of acoustic modes, an important breakthrough of the Kepler mission is the detection of nonradial gravity-dominated mixed-mode oscillations in red giants. Unlike pure acoustic modes, mixed modes probe deeply into the interior of stars, allowing the stellar core properties and evolution of stars to be derived. In this work, using the gravity-mode period spacing and the large frequency separation, we construct the ΔΠ{sub 1}–Δ ν asteroseismic diagram from models of subgiants and red giants with various masses and metallicities. The relationship ΔΠ{sub 1}–Δ ν is able to constrain the ages and masses of the subgiants. Meanwhile, for red giants with masses above 1.5 M {sub ⊙}, the ΔΠ{sub 1}–Δ ν asteroseismic diagram can also work well to constrain the stellar age and mass. Additionally, we calculate the relative “isochrones” τ , which indicate similar evolution states especially for similar mass stars, on the ΔΠ{sub 1}–Δ ν diagram.

  8. Formation of dust grains with impurities in red giant winds

    Science.gov (United States)

    Dominik, Carsten

    1994-01-01

    Among the several proposed carriers of diffuse interstellar bands (DIB's) are impurities in small dust grains, especially in iron oxide grains (Huffman 1977) and silicate grains (Huffman 1970). Most promising are single ion impurities since they can reproduce the observed band widths (Whittet 1992). These oxygen-rich grains are believed to originate mostly in the mass flows from red giants and in supernovae ejecta (e.g. Gehrz 1989). A question of considerable impact for the origin of DIB's is therefore, whether these grains are produced as mainly clean crystals or as some dirty materials. A formalism has been developed that allows tracking of the heterogeneous growth of a dust grain and its internal structure during the dust formation process. This formalism has been applied to the dust formation in the outflow from a red giant star.

  9. Asteroseismology of 16,000 Kepler Red Giants

    DEFF Research Database (Denmark)

    Yu, Jie; Huber, Daniel; Bedding, Timothy R.

    2018-01-01

    (sigma(M) = 7.8%), radius (sigma(R) = 2.9%), and thus surface gravity (sigma(log g) = 0.01 dex). Thanks to the large red giant sample, we confirm that red-giant-branch (RGB) and helium-core-burning (HeB) stars collectively differ in the distribution of oscillation amplitude, granulation power, and width...

  10. Surface effects on the red giant branch

    Science.gov (United States)

    Ball, W. H.; Themeßl, N.; Hekker, S.

    2018-05-01

    Individual mode frequencies have been detected in thousands of individual solar-like oscillators on the red giant branch (RGB). Fitting stellar models to these mode frequencies, however, is more difficult than in main-sequence stars. This is partly because of the uncertain magnitude of the surface effect: the systematic difference between observed and modelled frequencies caused by poor modelling of the near-surface layers. We aim to study the magnitude of the surface effect in RGB stars. Surface effect corrections used for main-sequence targets are potentially large enough to put the non-radial mixed modes in RGB stars out of order, which is unphysical. Unless this can be circumvented, model-fitting of evolved RGB stars is restricted to the radial modes, which reduces the number of available modes. Here, we present a method to suppress gravity modes (g-modes) in the cores of our stellar models, so that they have only pure pressure modes (p-modes). We show that the method gives unbiased results and apply it to three RGB solar-like oscillators in double-lined eclipsing binaries: KIC 8410637, KIC 9540226 and KIC 5640750. In all three stars, the surface effect decreases the model frequencies consistently by about 0.1-0.3 μHz at the frequency of maximum oscillation power νmax, which agrees with existing predictions from three-dimensional radiation hydrodynamics simulations. Though our method in essence discards information about the stellar cores, it provides a useful step forward in understanding the surface effect in RGB stars.

  11. Red giants as precursors of planetary nebulae

    International Nuclear Information System (INIS)

    Renzini, A.

    1981-01-01

    It is generally accepted that Planetary Nebulae are produced by asymptotic giant-branch stars. Therefore, several properties of planetary nebulae are discussed in the framework of the current theory of stellar evolution. (Auth.)

  12. From red giants to planetary nebulae: Asymmetries, dust, and polarization

    International Nuclear Information System (INIS)

    Johnson, J.J.

    1990-01-01

    In order to investigate the development of aspherical planetary nebulae, polarimetry was obtained for a group of planetary nebulae and for objects that will evolve into planetary nebulae, i.e., red giants, late asymptotic giant branch (AGB) objects, proto-planetary nebulae, and young planetary nebulae. To study the dust around the objects in our sample, we also used data from the Infrared Astronomy Satellite (IRAS) mission. The youngest objects in our survey, red giants, had the hottest dust temperatures while planetary nebulae had the coolest. Most of the objects were intrinsically polarized, including the red giants. This indicated that the circumstellar dust shells of these objects were aspherical. Both carbon- and oxygen-rich objects could be intrinsically polarized. The intrinsic polarizations of a sample of our objects were modeled using an ellipsoidal circumstellar dust shell. The findings of this study suggest that the asphericities that lead to an aspherical planetary nebula originate when a red giant begins to undergo mass loss. The polarization and thus the asphericity as the star evolves, with both reaching a maximum during the proto-planetary nebula stage. The circumstellar dust shell will dissipate after the proto-planetary nebulae stage since no new material is being added. The polarization of planetary nebulae will thus be low. In the most evolved planetary nebulae, the dust has either been destroyed or dissipated into the interstellar medium. In these objects no polarization was observed

  13. Physical properties of the red giant envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, W J [Instituto de Astronomia e Geofisico da Universidade de Sao Paulo (Brazil)

    1978-12-01

    In this work, several model envelopes are calculated for cool giant stars with mass loss due to the action of stellar radiation pressure on molecules and grains. Molecular profiles as well as average values of some physical parameters of the envelopes are obtained.

  14. Physical properties of the red giant envelopes

    International Nuclear Information System (INIS)

    Maciel, W.J.

    1978-01-01

    In this work, several model envelopes are calculated for cool giant stars with mass loss due to the action of stellar radiation pressure on molecules and grains. Molecular profiles as well as average values of some physical parameters of the envelopes are obtained [pt

  15. On the red giant titanium oxide bands

    Science.gov (United States)

    Hanni, L.; Sitska, J.

    1985-12-01

    The dependence of TiO absorption in cool oxygen-sequence giant stars on the Teff and log g of their atmospheres is investigated theoretically on the basis of spectra simulated using the computer program described by Hanni (1983) and the giant model atmospheres of Johnson et al. (1980). The temperature dependence of the intensity jumps at the head of the alpha(1.0) band is determined from simulated spectra, and the jumps are related to spectral types using the calibration of Ridgway et al. (1980). The results are presented in tables and graphs and shown to be in good agreement with the empirical Teff/intensity-jump correlation of Boyarchuk (1969).

  16. Grain-gas interaction in envelopes of red giants

    International Nuclear Information System (INIS)

    Maciel, W.J.

    1976-01-01

    A model for the ejection of the dust shell of red giant stars through the action of the stellar radiation pressure is developed. Being momentum-coupled to the gas, the dust shell can drive an effective mass loss. On the other hand, the grain injection rate into the interstellar space can be estimated [pt

  17. Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars

    NARCIS (Netherlands)

    Bedding, T.R.; Mosser, B.; Huber, D.; Montalbán, J.; Beck, P.; Christensen-Dalsgaard, J.; Elsworth, Y.P.; García, R.A.; Miglio, A.; Stello, D.; White, T.R.; de Ridder, J.; Hekker, S.; Aerts, C.; Barban, C.; Belkacem, K.; Broomhall, A.M.; Brown, T.M.; Buzasi, D.L.; Carrier, F.; Chaplin, W.J.; Di Mauro, M.P.; Dupret, M.-A.; Frandsen, S.; Gilliland, R.L.; Goupil, M.J.; Jenkins, J.M.; Kallinger, T.; Kawaler, S.; Kjeldsen, H.; Mathur, S.; Noels, A.; Silva Aguirre, V.; Ventura, P.

    2011-01-01

    Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include uncertainties

  18. Surface Compositions of Red Giant Stars in Globular Clusters

    Science.gov (United States)

    Cheng, Eric; Lau, Marie; Smith, Graeme; Chen, Brian

    2018-01-01

    Globular clusters (GCs) are excellent “laboratories” to study the formation and evolution of our galaxy. In order to understand, more specifically, the chemical compositions and stellar evolution of the stars in GCs, we ask whether or not deep internal mixing occurs in red giants or if in fact the compositions come from the primordial interstellar medium or previous generations of stars. It has been discovered that as a star evolves up the red giant branch, the surface carbon abundance decreases, which is evidence of deep internal mixing. We questioned whether these processes also affect O or Na abundance as a star evolves. We collected measurement data of red giants from GCs out of academic journals and sorted the data into catalogs. Then, we plotted the catalogs into figures, comparing surface O and Na each with stellar luminosity. Statistical tests were ran to quantify the amount of correlation between the variables. Out of 27 GCs, we concluded that eight show a positive correlation between Na and luminosity, and two show a negative correlation between O and luminosity. Properties of GCs were compared to determine if chemical distribution in stars depends on GCs as the self-enrichment scenario suggests. We created histograms of sodium distribution to test for bimodality to examine if there are separate trends in each GC. In six GCs, two different sequences of red giants appear for Na versus luminosity, suggesting evidence that the depth of mixing may differ among each red giant in a GC. This study has provided new evidence that the changing chemical abundances on the surfaces of red giants can be due to stellar evolutionary effects and deep internal mixing, which may not necessarily depend on the GC and may differ in depth among each red giant. Through this study, we learn more about stellar evolution which will eventually help us understand the origins of our universe. Most of this work was carried out by high school students working under the auspices of

  19. Qualitative explanations for red giant formation

    International Nuclear Information System (INIS)

    Bhaskar, R.; Nigam, A.

    1991-01-01

    Recent research on giant formation has focused on the need for qualitative explanations. The explanations have the following general, qualitative form: the polytrope n assumes a certain value, that makes (d ln r)/(d ln z) take on a very large value; large increases in r can then be explained in terms of small changes in the variable z. This form is applicable to all the explanations current in the literature: they all have (1) either implicitly or explicitly, both a hydrostatic component and a luminosity-opacity component, and (2) a reliance on singular solutions. Dimensional analysis reveals that power laws that assume the polytrope n to 5 are identical in both the hydrostatic and luminosity-based explanations. 12 refs

  20. Presence of mixed modes in red giants in binary systems

    Directory of Open Access Journals (Sweden)

    Themeßl Nathalie

    2017-01-01

    Full Text Available The frequencies of oscillation modes in stars contain valueable information about the stellar properties. In red giants the frequency spectrum also contains mixed modes, with both pressure (p and gravity (g as restoring force, which are key to understanding the physical conditions in the stellar core. We observe a high fraction of red giants in binary systems, for which g-dominated mixed modes are not pronounced. This trend leads us to investigate whether this is specific for binary systems or a more general feature. We do so by comparing the fraction of stars with only p-dominated mixed modes in binaries and in a larger set of stars from the APOKASC sample. We find only p-dominated mixed modes in about 50% of red giants in detached eclipsing binaries compared to about 4% in the large sample. This could indicate that this phenomenon is tightly related to binarity and that the binary fraction in the APOKASC sample is about 8%.

  1. Violet and visual flux problems in red giant stars

    International Nuclear Information System (INIS)

    Faulkner, D.R.

    1989-01-01

    Red giant stars are sites of many astrophysically interesting processes and are important links to late stages of stellar evolution and the chemical history of the galaxy. Much of what is known about stars comes from their spectra, which are formed in the outer layers (atmospheres). Unfortunately the low temperatures in red giant atmospheres promote the formation of many molecules, and the resultant complexity of the spectra has slowed progress in obtaining good models of these objects and leaves many unanswered questions. Several of these problems are investigated. Spectra of red giants provide a natural classification according to composition: M stars are oxygen rich, C stars are carbon rich, while S stars are intermediate. One long standing problem with C stars has been the explanation of the severe lack of energy flux in the violet and near ultraviolet part of their spectrum, generally attributed to an unusual opacity. Results show that one source, SiC, is untenable, while the case for the other, C3, is severely weakened. Synthetic spectra from atmospheric models are compared to spectra of TX Psc, a C star, to show that the contribution of thousands of atomic lines are probably responsible for the violet and ultraviolet flux deficiency. The agreement between the synthetic spectra and observations is very good. K and M type stars also have a violet flux deficiency, though it is less severe than with carbon stars

  2. RE-INFLATED WARM JUPITERS AROUND RED GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Eric D. [Institute for Astronomy, Royal Observatory Edinburgh, University of Edinburgh, Blackford Hill, Edinburgh (United Kingdom); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2016-02-10

    Since the discovery of the first transiting hot Jupiters, models have sought to explain the anomalously large radii of highly irradiated gas giants. We now know that the size of hot Jupiter radius anomalies scales strongly with a planet's level of irradiation and numerous models like tidal heating, ohmic dissipation, and thermal tides have since been developed to help explain these inflated radii. In general, however, these models can be grouped into two broad categories: models that directly inflate planetary radii by depositing a fraction of the incident irradiation into the interior and models that simply slow a planet's radiative cooling, allowing it to retain more heat from formation and thereby delay contraction. Here we present a new test to distinguish between these two classes of models. Gas giants orbiting at moderate orbital periods around post-main-sequence stars will experience enormous increases to their irradiation as their host stars move up the sub-giant and red-giant branches. If hot Jupiter inflation works by depositing irradiation into the planet's deep interiors then planetary radii should increase in response to the increased irradiation. This means that otherwise non-inflated gas giants at moderate orbital periods of >10 days can re-inflate as their host stars evolve. Here we explore the circumstances that can lead to the creation of these “re-inflated” gas giants and examine how the existence or absence of such planets can be used to place unique constraints on the physics of the hot Jupiter inflation mechanism. Finally, we explore the prospects for detecting this potentially important undiscovered population of planets.

  3. HD 181068: A Red Giant in a Triply Eclipsing Compact Hierarchical Triple System

    DEFF Research Database (Denmark)

    Derekas, A.; Kiss, Lazlo L.; Borkovits, T.

    2011-01-01

    by ground-based spectroscopy and interferometry, which show it to be a hierarchical triple with two types of mutual eclipses. The primary is a red giant that is in a 45-day orbit with a pair of red dwarfs in a close 0.9-day orbit. The red giant shows evidence for tidally induced oscillations that are driven...

  4. RED GIANTS IN ECLIPSING BINARY AND MULTIPLE-STAR SYSTEMS: MODELING AND ASTEROSEISMIC ANALYSIS OF 70 CANDIDATES FROM KEPLER DATA

    International Nuclear Information System (INIS)

    Gaulme, P.; McKeever, J.; Rawls, M. L.; Jackiewicz, J.; Mosser, B.; Guzik, J. A.

    2013-01-01

    Red giant stars are proving to be an incredible source of information for testing models of stellar evolution, as asteroseismology has opened up a window into their interiors. Such insights are a direct result of the unprecedented data from space missions CoRoT and Kepler as well as recent theoretical advances. Eclipsing binaries are also fundamental astrophysical objects, and when coupled with asteroseismology, binaries provide two independent methods to obtain masses and radii and exciting opportunities to develop highly constrained stellar models. The possibility of discovering pulsating red giants in eclipsing binary systems is therefore an important goal that could potentially offer very robust characterization of these systems. Until recently, only one case has been discovered with Kepler. We cross-correlate the detected red giant and eclipsing-binary catalogs from Kepler data to find possible candidate systems. Light-curve modeling and mean properties measured from asteroseismology are combined to yield specific measurements of periods, masses, radii, temperatures, eclipse timing variations, core rotation rates, and red giant evolutionary state. After using three different techniques to eliminate false positives, out of the 70 systems common to the red giant and eclipsing-binary catalogs we find 13 strong candidates (12 previously unknown) to be eclipsing binaries, one to be a non-eclipsing binary with tidally induced oscillations, and 10 more to be hierarchical triple systems, all of which include a pulsating red giant. The systems span a range of orbital eccentricities, periods, and spectral types F, G, K, and M for the companion of the red giant. One case even suggests an eclipsing binary composed of two red giant stars and another of a red giant with a δ-Scuti star. The discovery of multiple pulsating red giants in eclipsing binaries provides an exciting test bed for precise astrophysical modeling, and follow-up spectroscopic observations of many of the

  5. From red giant to planetary nebula - Dust, asymmetry, and polarization

    International Nuclear Information System (INIS)

    Johnson, J.J.; Jones, T.J.

    1991-01-01

    The polarization characteristics of stars in the stages of evolution from red giant to planetary nebula are investigated. Polarization is found to be a characteristic of the majority of these stars. The maximum observed polarization increases with age as the star evolves up the asymptotic giant branch (AGB) to the protoplanetary nebula phase, where the polarization reaches a maximum. The polarization then decreases as the star further evolves into a planetary nebula. These results indicate that aspherical mass loss is likely to be a continual feature of the late stages of stellar evolution, maintaining a clear continuity throughout the life of a star from the moment it first develops a measurable dust shell. The aspherical morphology seen in planetary nebulae has its origin in an intrinsic property of the star that is present at least as early as its arrival at the base of the AGB. 77 refs

  6. Theoretical red-giant branches for globular clusters

    International Nuclear Information System (INIS)

    VandenBerg, D.A.

    1984-01-01

    The authors reports computations of stellar evolutionary sequences from the base of the red-giant branch to the helium flash. Representative models with masses in the range of 0.8 to 0.9 solar masses were selected in order that the stars on the giant branches had ages of approximately 16 billion yr. Initial numerical experiments indicated that a value of α = 1.6 for the ratio of the mixing length to the pressure scale height was needed to provide the best of the Z = 0.0001 model sequence with the observations of M92. Sequences for the other assumed metallicities, Z = 0.0003, 0.001, 0.003, and 0.006, were then computed for the same value of the mixing-length parameter and overlayed directly on the observations. (Auth.)

  7. Neutron star/red giant encounters in globular clusters

    International Nuclear Information System (INIS)

    Bailyn, C.D.

    1988-01-01

    The author presents a simple expression for the amount by which xsub(crit) is diminished as a star evolves xsub(crit) Rsub(crit)/R*, where Rsub(crit) is the maximum distance of closest approach between two stars for which the tidal energy is sufficient to bind the system, and R* is the radius of the star on which tides are being raised. Also it is concluded that tidal capture of giants by neutron stars resulting in binary systems is unlikely in globular clusters. However, collisions between neutron stars and red giants, or an alternative process involving tidal capture of a main-sequence star into an initially detached binary system, may result either in rapidly rotating neutron stars or in white dwarf/neutron star binaries. (author)

  8. Giant magnetoresistance through a single molecule.

    Science.gov (United States)

    Schmaus, Stefan; Bagrets, Alexei; Nahas, Yasmine; Yamada, Toyo K; Bork, Annika; Bowen, Martin; Beaurepaire, Eric; Evers, Ferdinand; Wulfhekel, Wulf

    2011-03-01

    Magnetoresistance is a change in the resistance of a material system caused by an applied magnetic field. Giant magnetoresistance occurs in structures containing ferromagnetic contacts separated by a metallic non-magnetic spacer, and is now the basis of read heads for hard drives and for new forms of random access memory. Using an insulator (for example, a molecular thin film) rather than a metal as the spacer gives rise to tunnelling magnetoresistance, which typically produces a larger change in resistance for a given magnetic field strength, but also yields higher resistances, which are a disadvantage for real device operation. Here, we demonstrate giant magnetoresistance across a single, non-magnetic hydrogen phthalocyanine molecule contacted by the ferromagnetic tip of a scanning tunnelling microscope. We measure the magnetoresistance to be 60% and the conductance to be 0.26G(0), where G(0) is the quantum of conductance. Theoretical analysis identifies spin-dependent hybridization of molecular and electrode orbitals as the cause of the large magnetoresistance.

  9. A sample of potential disk hosting first ascent red giants

    Science.gov (United States)

    Steele, Amy; Debes, John

    2018-01-01

    Observations of (sub)giants with planets and disks provide the first set of proof that disks can survive the first stages of post-main-sequence evolution, even though the disks are expected to dissipate by this time. The infrared (IR) excesses present around a number of post-main-sequence (PMS) stars could be due to a traditional debris disk with planets (e.g. kappa CrB), some remnant of enhanced mass loss (e.g. the shell-like structure of R Sculptoris), and/or background contamination. We present a sample of potential disk hosting first ascent red giants. These stars all have infrared excesses at 22 microns, and possibly host circumstellar debris. We summarize the characteristics of the sample to better inform the incidence rates of thermally emitting material around giant stars. A thorough follow-up study of these candidates would serve as the first step in probing the composition of the dust in these systems that have left the main sequence, providing clues to the degree of disk processing that occurs beyond the main-sequence.

  10. Radio Emission from Red-Giant Hot Jupiters

    Science.gov (United States)

    Fujii, Yuka; Spiegel, David S.; Mroczkowski, Tony; Nordhaus, Jason; Zimmerman, Neil T.; Parsons, Aaron R.; Mirbabayi, Mehrdad; Madhusudhan, Nikku

    2016-01-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such "Red-Giant Hot Jupiters" (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array.

  11. RADIO EMISSION FROM RED-GIANT HOT JUPITERS

    International Nuclear Information System (INIS)

    Fujii, Yuka; Spiegel, David S.; Mroczkowski, Tony; Nordhaus, Jason; Zimmerman, Neil T.; Parsons, Aaron R.; Mirbabayi, Mehrdad; Madhusudhan, Nikku

    2016-01-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main-sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such “Red-Giant Hot Jupiters” (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array

  12. RADIO EMISSION FROM RED-GIANT HOT JUPITERS

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Yuka [Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, 152-8550 (Japan); Spiegel, David S. [Analytics and Algorithms, Stitch Fix, San Francisco, CA 94103 (United States); Mroczkowski, Tony [Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (United States); Nordhaus, Jason [Department of Science and Mathematics, National Technical Institute for the Deaf, Rochester Institute of Technology, Rochester, NY 14623 (United States); Zimmerman, Neil T. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Parsons, Aaron R. [Astronomy Department, University of California, Berkeley, CA (United States); Mirbabayi, Mehrdad [Astrophysics Department, Institute for Advanced Study, Princeton, NJ 08540 (United States); Madhusudhan, Nikku, E-mail: yuka.fujii@elsi.jp [Astronomy Department, University of Cambridge (United Kingdom)

    2016-04-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main-sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such “Red-Giant Hot Jupiters” (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array.

  13. Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars

    DEFF Research Database (Denmark)

    Bedding, Timothy R.; Mosser, Benoit; Huber, Daniel

    2011-01-01

    Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include...... uncertainties in the amount of mass lost at the surface before helium ignition and the amount of internal mixing from rotation and other processes. Progress is hampered by our inability to distinguish between red giants burning helium in the core and those still only burning hydrogen in a shell....... Asteroseismology offers a way forward, being a powerful tool for probing the internal structures of stars using their natural oscillation frequencies. Here we report observations of gravity-mode period spacings in red giants that permit a distinction between evolutionary stages to be made. We use high...

  14. Observations of red-giant variable stars by Aboriginal Australians

    Science.gov (United States)

    Hamacher, Duane W.

    2018-04-01

    Aboriginal Australians carefully observe the properties and positions of stars, including both overt and subtle changes in their brightness, for subsistence and social application. These observations are encoded in oral tradition. I examine two Aboriginal oral traditions from South Australia that describe the periodic changing brightness in three pulsating, red-giant variable stars: Betelgeuse (Alpha Orionis), Aldebaran (Alpha Tauri), and Antares (Alpha Scorpii). The Australian Aboriginal accounts stand as the only known descriptions of pulsating variable stars in any Indigenous oral tradition in the world. Researchers examining these oral traditions over the last century, including anthropologists and astronomers, missed the description of these stars as being variable in nature as the ethnographic record contained several misidentifications of stars and celestial objects. Arguably, ethnographers working on Indigenous Knowledge Systems should have academic training in both the natural and social sciences.

  15. Atmospheric parameters of 82 red giants in the Kepler field

    DEFF Research Database (Denmark)

    Overaa Thygesen, Anders; Frandsen, Søren; Bruntt, Hans

    2012-01-01

    spectroscopy and photometry shows good agreement within the uncertainties. We find good agreement between the spectroscopic log g and the log g derived from asteroseismology. Also, we see indications of a potential metallicity effect on the stellar oscillations. Conclusions. We have determined the fundamental...... elements were measured using equivalent widths of the spectral lines. Results. We identify discrepancies in log g and [Fe/H], compared to the parameters based on photometric indices in the Kepler Input Catalogue (larger than 2.0 dex for log g and [Fe/H] for individual stars). The Teff found from...... parameters and element abundances of 82 red giants. The large discrepancies between the spectroscopic log g and [Fe/H] and values in the Kepler Input Catalogue emphasize the need for further detailed spectroscopic follow-up of the Kepler targets in order to produce reliable results from the asteroseismic...

  16. MAGNESIUM ISOTOPE RATIOS IN ω CENTAURI RED GIANTS

    International Nuclear Information System (INIS)

    Da Costa, G. S.; Norris, John E.; Yong, David

    2013-01-01

    We have used the high-resolution observations obtained at the Anglo-Australian Telescope with Ultra-High Resolution Facility (R ∼ 100,000) and at Gemini-S with b-HROS (R ∼ 150,000) to determine magnesium isotope ratios for seven ω Cen red giants that cover a range in iron abundance from [Fe/H] = –1.78 to –0.78 dex, and for two red giants in M4 (NGC 6121). The ω Cen stars sample both the ''primordial'' (i.e., O-rich, Na- and Al-poor) and the ''extreme'' (O-depleted, Na- and Al-rich) populations in the cluster. The primordial population stars in both ω Cen and M4 show ( 25 Mg, 26 Mg)/ 24 Mg isotopic ratios that are consistent with those found for the primordial population in other globular clusters with similar [Fe/H] values. The isotopic ratios for the ω Cen extreme stars are also consistent with those for extreme population stars in other clusters. The results for the extreme population stars studied indicate that the 26 Mg/ 24 Mg ratio is highest at intermediate metallicities ([Fe/H] 26 Mg in the extreme population stars is notably higher than that of 25 Mg, in contrast to model predictions. The 25 Mg/ 24 Mg isotopic ratio in fact does not show any obvious dependence on either [Fe/H] or [Al/Fe] nor, intriguingly, any obvious difference between the primordial and extreme population stars.

  17. Tests of two convection theories for red giant and red supergiant envelopes

    Science.gov (United States)

    Stothers, Richard B.; Chin, Chao-Wen

    1995-01-01

    Two theories of stellar envelope convection are considered here in the context of red giants and red supergiants of intermediate to high mass: Boehm-Vitense's standard mixing-length theory (MLT) and Canuto & Mazzitelli's new theory incorporating the full spectrum of turbulence (FST). Both theories assume incompressible convection. Two formulations of the convective mixing length are also evaluated: l proportional to the local pressure scale height (H(sub P)) and l proportional to the distance from the upper boundary of the convection zone (z). Applications to test both theories are made by calculating stellar evolutionary sequences into the red zone (z). Applications to test both theories are made by calculating stellar evolutionary sequences into the red phase of core helium burning. Since the theoretically predicted effective temperatures for cool stars are known to be sensitive to the assigned value of the mixing length, this quantity has been individually calibrated for each evolutionary sequence. The calibration is done in a composite Hertzsprung-Russell diagram for the red giant and red supergiant members of well-observed Galactic open clusters. The MLT model requires the constant of proportionality for the convective mixing length to vary by a small but statistically significant amount with stellar mass, whereas the FST model succeeds in all cases with the mixing lenghth simply set equal to z. The structure of the deep stellar interior, however, remains very nearly unaffected by the choices of convection theory and mixing lenghth. Inside the convective envelope itself, a density inversion always occurs, but is somewhat smaller for the convectively more efficient MLT model. On physical grounds the FST model is preferable, and seems to alleviate the problem of finding the proper mixing length.

  18. Study at radio wavelengths of circumstellar envelopes around red giants

    International Nuclear Information System (INIS)

    Do Thi Hoai

    2015-01-01

    The thesis studies mass losing AGB stars and their circumstellar environments, with focus on the development of stellar outflows and their interaction with the surrounding medium. It uses emission from two tracers: carbon monoxide (CO), through its rotational lines in the millimeter range, probes the inner regions of the circumstellar shells out to photodissociation distances, while atomic hydrogen (HI, 21 cm) is better suited to the study of the external regions. The high spectral and spatial resolutions achieved in radio observations allow for a detailed exploration of the kinematics of the relatively slow outflows of red giants. After having introduced the subject, I discuss the case of an S-type star (RS Cnc) that has been observed in CO with the IRAM telescopes, as well as in HI with the VLA, concentrating on the modelling of the spatially resolved CO line profiles and illustrating the complementarity between HI and CO. Results of the CO modelling of other AGB stars observed at IRAM (EP Aqr, XHer and RXBoo) and of a post-AGB star observed with ALMA, the Red Rectangle, are also presented. The formation of the HI line profile in various cases of mass losing AGB stars, in particular YCVn for which a model is presented, is studied next, exploring several effects that might explain the lack of detected emission from stars with high mass loss rates. Similarities between the bipolar outflows of the AGB stars that have been studied, all having mass loss rates in the region of 10"-"7 solar masses per year and displaying nearly spherical morphologies are discussed together with the information on the gas temperature obtained from the simultaneous observation of two CO lines. (author)

  19. The development of the red giant branch. II - Astrophysical properties

    Science.gov (United States)

    Sweigart, Allen V.; Greggio, Laura; Renzini, Alvio

    1990-01-01

    Evolutionary sequences developed in another paper are used here to investigate the properties of the red giant branch (RGB) phase transition. Results are found for compositions in the range Y(MS) between 0.20 and 0.30 and Z between 0.004 and 0.04. The transition mass M(HeF) increases as either Y(MS) decreases or Z increases. The stellar population transition age t(HeF) is virtually independent of composition and close to 0.6 Gyr. The RGB phase transition occurs almost abruptly over a mass range of only a few tenths of a solar mass or, equivalently, over a time interval of about 0.2 Gyr in the life of a stellar population. During the RGB phase transition the core mass Mc at helium ignition increases very rapidly by about 0.15 solar mass, while the luminosity at the tip of the RGB increases by about one order of magnitude. Absolute minima are found for the values of Mc and the RGB tip luminosity.

  20. Modelling linewidths of Kepler red giants in NGC 6819

    Science.gov (United States)

    Aarslev, Magnus J.; Houdek, Günter; Handberg, Rasmus; Christensen-Dalsgaard, Jørgen

    2018-04-01

    We present a comparison between theoretical, frequency-dependent, damping rates and linewidths of radial-mode oscillations in red-giant stars located in the open cluster NGC 6819. The calculations adopt a time-dependent non-local convection model, with the turbulent pressure profile being calibrated to results of 3D hydrodynamical simulations of stellar atmospheres. The linewidths are obtained from extensive peakbagging of Kepler lightcurves. These observational results are of unprecedented quality owing to the long continuous observations by Kepler. The uniqueness of the Kepler mission also means that, for asteroseismic properties, this is the best data that will be available for a long time to come. We therefore take great care in modelling nine RGB stars in NGC 6819 using information from 3D simulations to obtain realistic temperature stratifications and calibrated turbulent pressure profiles. Our modelled damping rates reproduce well the Kepler observations, including the characteristic depression in the linewidths around the frequency of maximum oscillation power. Furthermore, we thoroughly test the sensitivity of the calculated damping rates to changes in the parameters of the nonlocal convection model.

  1. Amplitude Variations in Pulsating Red Giants. II. Some Systematics

    Science.gov (United States)

    Percy, J. R.; Laing, J.

    2017-12-01

    In order to extend our previous studies of the unexplained phenomenon of cyclic amplitude variations in pulsating red giants, we have used the AAVSO time-series analysis package vstar to analyze long-term AAVSO visual observations of 50 such stars, mostly Mira stars. The relative amount of the variation, typically a factor of 1.5, and the time scale of the variation, typically 20-35 pulsation periods, are not significantly different in longer-period, shorter-period, and carbon stars in our sample, and they also occur in stars whose period is changing secularly, perhaps due to a thermal pulse. The time scale of the variations is similar to that in smaller-amplitude SR variables, but the relative amount of the variation appears to be larger in smaller-amplitude stars, and is therefore more conspicuous. The cause of the amplitude variations remains unclear, though they may be due to rotational modulation of a star whose pulsating surface is dominated by the effects of large convective cells.

  2. Lithium in Open Cluster Red Giants Hosting Substellar Companions

    Science.gov (United States)

    Carlberg, Joleen K.; Smith, Verne V.; Cunha, Katia; Carpenter, Kenneth G.

    2016-02-01

    We have measured stellar parameters, [Fe/H], lithium abundances, rotation, and 12C/13C in a small sample of red giants (RGs) in three open clusters that are each home to a RG star that hosts a substellar companion (SSC) (NGC 2423 3, NGC 4349 127, and BD+12 1917 in M67). Our goal is to explore whether the presence of SSCs influences the Li content. Both 12C/13C and stellar rotation are measured as additional tracers of stellar mixing. One of the companion hosts, NGC 2423 3, is found to be Li-rich with A(Li){}{{NLTE}} = 1.56 dex, and this abundance is significantly higher than the A(Li) of the two comparison stars in NGC 2423. All three SSC hosts have the highest A(Li) and 12C/13C when compared to the control RGs in their respective clusters; however, except for NGC 2423 3, at least one control star has similarly high abundances within the uncertainties. Higher A(Li) could suggest that the formation or presence of planets plays a role in the degree of internal mixing on or before the RG branch. However, a multitude of factors affect A(Li) during the RG phase, and when the abundances of our sample are compared with the abundances of RGs in other open clusters available in the literature, we find that they all fall well within a much larger distribution of A(Li) and 12C/13C. Thus, even the high Li in NGC 2423 3 cannot be concretely tied to the presence of the SSC.

  3. Nuclear isovector giant resonances excited by pion single charge exchange

    International Nuclear Information System (INIS)

    King, B.H.

    1993-07-01

    This thesis is an experimental study of isovector giant resonances in light nuclei excited by pion single charge exchange reactions. Giant dipole resonances in light nuclei are known to be highly structured. For the mass 9 and 13 giant dipole resonances, isospin considerations were found to be very important to understanding this structure. by comparing the excitation functions from cross section measurements of the (π + , π 0 ) and (π, π 0 ) inclusive reactions, the authors determined the dominant isospin structure of the analog IVGR's. The comparison was made after decomposing the cross section into resonant and non-resonant components. This decomposition is made in the framework of strong absorption and quasi-free scattering. Measurements in the region of the isovector giant dipole resonances (IVGDR) were made to cover the inclusive angular distributions out to the second minimum. Study of the giant resonance decay process provides further understanding of the resonances. This study was carried out by observing the (π + , π 0 p) coincident reactions involving the resonances of 9 B and 13 N excited from 9 Be and 13 C nuclei. These measurements determined the spectra of the decay protons. This method also permitted a decomposition of the giant resonances into their isospin components. The multipolarities of the resonances were revealed by the decay proton angular correlations which, for dipoles, are of the form 1 + A 2 P 2 (cos θ)

  4. Amplitudes of solar-like oscillations: Constraints from red giants in open clusters observed by Kepler

    DEFF Research Database (Denmark)

    Stello, Dennis; Huber, Daniel; Kallinger, Thomas

    2011-01-01

    implies that the stellar parameters can be measured to much higher precision than what is usually achievable for single stars. This makes clusters ideal for exploring the relation between the mode amplitude of solar-like oscillations and the global stellar properties. We have analyzed data obtained......Scaling relations that link asteroseismic quantities to global stellar properties are important for gaining understanding of the intricate physics that underpins stellar pulsations. The common notion that all stars in an open cluster have essentially the same distance, age, and initial composition...... with NASA's Kepler space telescope to study solar-like oscillations in 100 red giant stars located in either of the three open clusters, NGC 6791, NGC 6819, and NGC 6811. By fitting the measured amplitudes to predictions from simple scaling relations that depend on luminosity, mass, and effective...

  5. Surprising Rapid Collapse of Sirius B from Red Giant to White Dwarf Through Mass Transfer to Sirius a

    Science.gov (United States)

    Yousef, Shahinaz; Ali, Ola

    2013-03-01

    Sirius was observed in antiquity as a red star. In his famous astronomy textbook the Almagest written 140 AD, Ptolemy described the star Sirius as fiery red. He curiously depicted it as one of six red-colored stars. The other five are class M and K stars, such as Arcturus and Betelgeuse. Apparent confirmation in ancient Greek and Roman sources are found and Sirius was also reported red in Europe about 1400 years ago. Sirius must have changed to a white dwarf in the night of Ascension. The star chapter in the Quran started with "by the star as it collapsed (1) your companion have not gone astray nor being misled (2), and in verse 49 which is the rotation period of the companion Sirius B around Sirius A, it is said" He is the Lord of Sirius (49). If Sirius actually was red what could have caused it to change into the brilliant bluish-white star we see today? What the naked eye perceives as a single star is actually a binary star system, consisting of a white main sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B. The red color indicates that the star seen then was a red giant. It looks that what they have seen in antiquity was Sirius B which was then a red giant and it collapsed to form a white dwarf. Since there is no evidence of a planetary nebula, then the red Sirius paradox can be solved in terms of stellar evolution with mass transfer. Sirius B was the most massive star which evolved to a red giant and filled the Roche lobe. Mass transfer to Sirius A occurred through the Lagrangian point. Sirius A then became more massive while Sirius B lost mass and shrank. Sirius B then collapsed abruptly into a white dwarf. In the case of Algol, Ptolmy observed it as white star but it was red at the time of El sufi. At present it is white. The rate of mass transfer from Sirius B to Sirius A, and from Algol B to A is estimated from observational data of colour change from red to bullish white to be 0

  6. The mass and age of the first SONG target: the red giant 46 LMi

    Science.gov (United States)

    Frandsen, S.; Fredslund Andersen, M.; Brogaard, K.; Jiang, C.; Arentoft, T.; Grundahl, F.; Kjeldsen, H.; Christensen-Dalsgaard, J.; Weiss, E.; Pallé, P.; Antoci, V.; Kjærgaard, P.; Sørensen, A. N.; Skottfelt, J.; Jørgensen, U. G.

    2018-05-01

    Context. The Stellar Observation Network Group (SONG) is an initiative to build a worldwide network of 1m telescopes with high-precision radial-velocity spectrographs. Here we analyse the first radial-velocity time series of a red-giant star measured by the SONG telescope at Tenerife. The asteroseismic results demonstrate a major increase in the achievable precision of the parameters for red-giant stars obtainable from ground-based observations. Reliable tests of the validity of these results are needed, however, before the accuracy of the parameters can be trusted. Aims: We analyse the first SONG time series for the star 46 LMi, which has a precise parallax and an angular diameter measured from interferometry, and therefore a good determination of the stellar radius. We use asteroseismic scaling relations to obtain an accurate mass, and modelling to determine the age. Methods: A 55-day time series of high-resolution, high S/N spectra were obtained with the first SONG telescope. We derive the asteroseismic parameters by analysing the power spectrum. To give a best guess on the large separation of modes in the power spectrum, we have applied a new method which uses the scaling of Kepler red-giant stars to 46 LMi. Results: Several methods have been applied: classical estimates, seismic methods using the observed time series, and model calculations to derive the fundamental parameters of 46 LMi. Parameters determined using the different methods are consistent within the uncertainties. We find the following values for the mass M (scaling), radius R (classical), age (modelling), and surface gravity (combining mass and radius): M = 1.09 ± 0.04M⊙, R = 7.95 ± 0.11R⊙ age t = 8.2 ± 1.9 Gy, and logg = 2.674 ± 0.013. Conclusions: The exciting possibilities for ground-based asteroseismology of solar-like oscillations with a fully robotic network have been illustrated with the results obtained from just a single site of the SONG network. The window function is still a

  7. MULTI-WAVELENGTH RADIO CONTINUUM EMISSION STUDIES OF DUST-FREE RED GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    O' Gorman, Eamon; Harper, Graham M. [School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Brown, Alexander [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Drake, Stephen [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Richards, Anita M. S. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

    2013-10-01

    Multi-wavelength centimeter continuum observations of non-dusty, non-pulsating K spectral-type red giants directly sample their chromospheres and wind acceleration zones. Such stars are feeble emitters at these wavelengths, however, and previous observations have provided only a small number of modest signal-to-noise measurements slowly accumulated over three decades. We present multi-wavelength Karl G. Jansky Very Large Array thermal continuum observations of the wind acceleration zones of two dust-free red giants, Arcturus (α Boo: K2 III) and Aldebaran (α Tau: K5 III). Importantly, most of our observations of each star were carried out over just a few days, so that we obtained a snapshot of the different stellar atmospheric layers sampled at different wavelengths, independent of any long-term variability. We report the first detections at several wavelengths for each star including a detection at 10 cm (3.0 GHz: S band) for both stars and a 20 cm (1.5 GHz: L band) detection for α Boo. This is the first time single (non-binary) luminosity class III red giants have been detected at these continuum wavelengths. Our long-wavelength data sample the outer layers of α Boo's atmosphere where its wind velocity is approaching (or possibly has reached) its terminal value and the ionization balance is becoming frozen-in. For α Tau, however, our long-wavelength data are still sampling its inner atmosphere, where the wind is still accelerating probably due to its lower mass-loss rate. We compare our data with published semi-empirical models based on ultraviolet data, and the marked deviations highlight the need for new atmospheric models to be developed. Spectral indices are used to discuss the possible properties of the stellar atmospheres, and we find evidence for a rapidly cooling wind in the case of α Boo. Finally, we develop a simple analytical wind model for α Boo based on our new long-wavelength flux measurements.

  8. MULTI-WAVELENGTH RADIO CONTINUUM EMISSION STUDIES OF DUST-FREE RED GIANTS

    International Nuclear Information System (INIS)

    O'Gorman, Eamon; Harper, Graham M.; Brown, Alexander; Drake, Stephen; Richards, Anita M. S.

    2013-01-01

    Multi-wavelength centimeter continuum observations of non-dusty, non-pulsating K spectral-type red giants directly sample their chromospheres and wind acceleration zones. Such stars are feeble emitters at these wavelengths, however, and previous observations have provided only a small number of modest signal-to-noise measurements slowly accumulated over three decades. We present multi-wavelength Karl G. Jansky Very Large Array thermal continuum observations of the wind acceleration zones of two dust-free red giants, Arcturus (α Boo: K2 III) and Aldebaran (α Tau: K5 III). Importantly, most of our observations of each star were carried out over just a few days, so that we obtained a snapshot of the different stellar atmospheric layers sampled at different wavelengths, independent of any long-term variability. We report the first detections at several wavelengths for each star including a detection at 10 cm (3.0 GHz: S band) for both stars and a 20 cm (1.5 GHz: L band) detection for α Boo. This is the first time single (non-binary) luminosity class III red giants have been detected at these continuum wavelengths. Our long-wavelength data sample the outer layers of α Boo's atmosphere where its wind velocity is approaching (or possibly has reached) its terminal value and the ionization balance is becoming frozen-in. For α Tau, however, our long-wavelength data are still sampling its inner atmosphere, where the wind is still accelerating probably due to its lower mass-loss rate. We compare our data with published semi-empirical models based on ultraviolet data, and the marked deviations highlight the need for new atmospheric models to be developed. Spectral indices are used to discuss the possible properties of the stellar atmospheres, and we find evidence for a rapidly cooling wind in the case of α Boo. Finally, we develop a simple analytical wind model for α Boo based on our new long-wavelength flux measurements

  9. Multi-wavelength Radio Continuum Emission Studies of Dust-free Red Giants

    Science.gov (United States)

    O'Gorman, Eamon; Harper, Graham M.; Brown, Alexander; Dranke, Stephen; Richards, Anita M. S.

    2013-01-01

    Multi-wavelength centimeter continuum observations of non-dusty, non-pulsating K spectral-type red giants directly sample their chromospheres and wind acceleration zones. Such stars are feeble emitters at these wavelengths, however, and previous observations have provided only a small number of modest signal-to-noise measurements slowly accumulated over three decades. We present multi-wavelength Karl G. Jansky Very Large Array thermal continuum observations of the wind acceleration zones of two dust-free red giants, Arcturus (alpha Boo: K2 III) and Aldebaran (alpha Tau: K5 III). Importantly, most of our observations of each star were carried out over just a few days, so that we obtained a snapshot of the different stellar atmospheric layers sampled at different wavelengths, independent of any long-term variability. We report the first detections at several wavelengths for each star including a detection at 10 cm (3.0 GHz: S band) for both stars and a 20 cm (1.5 GHz: L band) detection for alpha Boo. This is the first time single (non-binary) luminosity class III red giants have been detected at these continuum wavelengths. Our long-wavelength data sample the outer layers of alpha Boo's atmosphere where its wind velocity is approaching (or possibly has reached) its terminal value and the ionization balance is becoming frozen-in. For alpha Tau, however, our long-wavelength data are still sampling its inner atmosphere, where the wind is still accelerating probably due to its lower mass-loss rate. We compare our data with published semi-empirical models based on ultraviolet data, and the marked deviations highlight the need for new atmospheric models to be developed. Spectral indices are used to discuss the possible properties of the stellar atmospheres, and we find evidence for a rapidly cooling wind in the case of alpha Boo. Finally, we develop a simple analytical wind model for alpha Boo based on our new long-wavelength flux measurements.

  10. Amplitudes of solar-like oscillations in red giants: Departures from the quasi-adiabatic approximation

    Directory of Open Access Journals (Sweden)

    Barban C.

    2013-03-01

    Full Text Available CoRoT and Kepler measurements reveal us that the amplitudes of solar-like oscillations detected in red giant stars scale from stars to stars in a characteristic way. This observed scaling relation is not yet fully understood but constitutes potentially a powerful diagnostic about mode physics. Quasi-adiabatic theoretical scaling relations in terms of mode amplitudes result in systematic and large differences with the measurements performed for red giant stars. The use of a non-adiabatic intensity-velocity relation derived from a non-adiabatic pulsation code significantly reduces the discrepancy with the CoRoT measurements. The origin of the remaining difference is still unknown. Departure from adiabatic eigenfunction is a very likely explanation that is investigated in the present work using a 3D hydrodynamical model of the surface layers of a representative red giant star.

  11. Sparsely-Observed Pulsating Red Giants in the AAVSO Observing Program

    Science.gov (United States)

    Percy, J. R.

    2018-06-01

    This paper reports on time-series analysis of 156 pulsating red giants (21 SRa, 52 SRb, 33 SR, 50 Lb) in the AAVSO observing program for which there are no more than 150-250 observations in total. Some results were obtained for 68 of these stars: 17 SRa, 14 SRb, 20 SR, and 17 Lb. These results generally include only an average period and amplitude. Many, if not most of the stars are undoubtedly more complex; pulsating red giants are known to have wandering periods, variable amplitudes, and often multiple periods including "long secondary periods" of unknown origin. These results (or lack thereof) raise the question of how the AAVSO should best manage the observation of these and other sparsely-observed pulsating red giants.

  12. Radial velocity curves of ellipsoidal red giant binaries in the Large Magellanic Cloud

    International Nuclear Information System (INIS)

    Nie, J. D.; Wood, P. R.

    2014-01-01

    Ellipsoidal red giant binaries are close binary systems where an unseen, relatively close companion distorts the red giant, leading to light variations as the red giant moves around its orbit. These binaries are likely to be the immediate evolutionary precursors of close binary planetary nebula and post-asymptotic giant branch and post-red giant branch stars. Due to the MACHO and OGLE photometric monitoring projects, the light variability nature of these ellipsoidal variables has been well studied. However, due to the lack of radial velocity curves, the nature of their masses, separations, and other orbital details has so far remained largely unknown. In order to improve this situation, we have carried out spectral monitoring observations of a large sample of 80 ellipsoidal variables in the Large Magellanic Cloud and we have derived radial velocity curves. At least 12 radial velocity points with good quality were obtained for most of the ellipsoidal variables. The radial velocity data are provided with this paper. Combining the photometric and radial velocity data, we present some statistical results related to the binary properties of these ellipsoidal variables.

  13. History of the stellar birthrate from lithium abundances in red giants

    International Nuclear Information System (INIS)

    Scalo, J.M.; Miller, G.E.

    1980-01-01

    The lithium abundance at the end of main-sequence evolution should increase strongly with mass for masses less than 1.4 M/sub sun/. It is shown that because of this dependence the frequency distribution of Li abundances in red giants is a sensitive probe of the history of the stellar birthrate in the solar neighborhood since the Li distribution directly reflects the stellar age distribution. A birthrate which decreases with time gives a smaller mean red giant Li abundance than an increasing birthrate because a larger fraction of red giants are older and hence less massive. Theoretical Li abundance frequency distributions are calculated for exponentially increasing, constant, and exponentially decreasing birthrates using a semiempirical prescription for main-sequence Li destruction, theoretical main-sequence lifetimes and red giant dilution factors, and self-consistent initial mass functions. The results are compared with the observed abundance distribution for 35 giants studied by Lambert and his colleagues. Allowing for uncertainties, we find that the ratio of present birthrate to average past birthrate has a value between 0.5 and 2. These limits are consistent with results of most other methods of determining the birthrate history, but the present method provides a considerably more stringent lower limit. It is also shown that, with more observational data, fluctuations in the birthrate with a time scale of about one billion years during the period between two and six billion years ago could be resolved

  14. Internal rotation of 13 low-mass low-luminosity red giants in the Kepler field

    Science.gov (United States)

    Triana, S. A.; Corsaro, E.; De Ridder, J.; Bonanno, A.; Pérez Hernández, F.; García, R. A.

    2017-06-01

    Context. The Kepler space telescope has provided time series of red giants of such unprecedented quality that a detailed asteroseismic analysis becomes possible. For a limited set of about a dozen red giants, the observed oscillation frequencies obtained by peak-bagging together with the most recent pulsation codes allowed us to reliably determine the core/envelope rotation ratio. The results so far show that the current models are unable to reproduce the rotation ratios, predicting higher values than what is observed and thus indicating that an efficient angular momentum transport mechanism should be at work. Here we provide an asteroseismic analysis of a sample of 13 low-luminosity low-mass red giant stars observed by Kepler during its first nominal mission. These targets form a subsample of the 19 red giants studied previously, which not only have a large number of extracted oscillation frequencies, but also unambiguous mode identifications. Aims: We aim to extend the sample of red giants for which internal rotation ratios obtained by theoretical modeling of peak-bagged frequencies are available. We also derive the rotation ratios using different methods, and compare the results of these methods with each other. Methods: We built seismic models using a grid search combined with a Nelder-Mead simplex algorithm and obtained rotation averages employing Bayesian inference and inversion methods. We compared these averages with those obtained using a previously developed model-independent method. Results: We find that the cores of the red giants in this sample are rotating 5 to 10 times faster than their envelopes, which is consistent with earlier results. The rotation rates computed from the different methods show good agreement for some targets, while some discrepancies exist for others.

  15. AMPLITUDES OF SOLAR-LIKE OSCILLATIONS: CONSTRAINTS FROM RED GIANTS IN OPEN CLUSTERS OBSERVED BY KEPLER

    International Nuclear Information System (INIS)

    Stello, Dennis; Huber, Daniel; Bedding, Timothy R.; Benomar, Othman; Kallinger, Thomas; Basu, Sarbani; Mosser, BenoIt; Hekker, Saskia; Mathur, Savita; GarcIa, Rafael A.; Kjeldsen, Hans; Grundahl, Frank; Christensen-Dalsgaard, Joergen; Gilliland, Ronald L.; Verner, Graham A.; Chaplin, William J.; Elsworth, Yvonne P.; Meibom, Soeren; Molenda-Zakowicz, Joanna; Szabo, Robert

    2011-01-01

    Scaling relations that link asteroseismic quantities to global stellar properties are important for gaining understanding of the intricate physics that underpins stellar pulsations. The common notion that all stars in an open cluster have essentially the same distance, age, and initial composition implies that the stellar parameters can be measured to much higher precision than what is usually achievable for single stars. This makes clusters ideal for exploring the relation between the mode amplitude of solar-like oscillations and the global stellar properties. We have analyzed data obtained with NASA's Kepler space telescope to study solar-like oscillations in 100 red giant stars located in either of the three open clusters, NGC 6791, NGC 6819, and NGC 6811. By fitting the measured amplitudes to predictions from simple scaling relations that depend on luminosity, mass, and effective temperature, we find that the data cannot be described by any power of the luminosity-to-mass ratio as previously assumed. As a result we provide a new improved empirical relation which treats luminosity and mass separately. This relation turns out to also work remarkably well for main-sequence and subgiant stars. In addition, the measured amplitudes reveal the potential presence of a number of previously unknown unresolved binaries in the red clump in NGC 6791 and NGC 6819, pointing to an interesting new application for asteroseismology as a probe into the formation history of open clusters.

  16. Spectroscopy of Six Red Giants in the Draco Dwarf Spheroidal Galaxy

    Science.gov (United States)

    Smith, Graeme H.; Siegel, Michael H.; Shetrone, Matthew D.; Winnick, Rebeccah

    2006-10-01

    Keck Observatory LRIS-B (Low Resolution Imaging Spectrometer) spectra are reported for six red giant stars in the Draco dwarf spheroidal galaxy and several comparison giants in the globular cluster M13. Indexes that quantify the strengths of the Ca II H and K lines, the λ3883 and λ4215 CN bands, and the λ4300 G band have been measured. These data confirm evidence of metallicity inhomogeneity within Draco obtained by previous authors. The four brightest giants in the sample have absolute magnitudes in the range -2.6intermediate-mass asymptotic giant branch stars to enrich the interstellar medium while star formation was still occurring. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  17. Modelling the Galactic bar using OGLE-II red clump giant stars

    NARCIS (Netherlands)

    Rattenbury, Nicholas J.; Mao, Shude; Sumi, Takahiro; Smith, Martin C.

    2007-01-01

    Red clump giant (RCG) stars can be used as distance indicators to trace the mass distribution of the Galactic bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration data base to constrain analytic triaxial models for the Galactic bar. We find the bar major-axis is

  18. Detailed Study of the Internal Structure of a Red-giant Star Observed with Kepler

    DEFF Research Database (Denmark)

    Di Mauro, M. P.; Ventura, R.; Cardini, D.

    2012-01-01

    We study the internal structure and evolutionary state of KIC 4351319, a red-giant star observed with the Kepler satellite. The use of 25 individual oscillation frequencies, together with the accurate atmospheric data provided by ground-based spectroscopic observations, allowed us to estimate the...

  19. Perfluorooctanesulfonate and periluorooctanoate in red panda and giant panda from China.

    Science.gov (United States)

    Dai, Jiayin; Li, Ming; Jin, Yihe; Saito, Norimitsu; Xu, Muqi; Wei, Fuwen

    2006-09-15

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) are important perfluorochemicals (PFCs) in various applications. Recently, it has been shown that these compounds are widespread in the environment, wildlife, and humans. The giant panda and the red panda belong to the order Carnivora, but are highly specialized as bamboo feeders. Both species are considered rare and endangered. In this study, we report for the first time on levels of PFOS and PFOA in serum of the giant panda and the red panda captured in zoos and animal parks from six provinces in China. PFOS was the predominant compound in all panda samples measured (ranging from 0.80 to 73.80 microg/L for red panda and from 0.76 to 19.00 microg/L for giant panda). The PFOA level ranged from 0.33 to 8.20 microg/L for red panda, and from 0.32 to 1.56 microg/L for giant panda. There was a positive significant correlation between concentrations of PFOS and PFOA in the serum obtained from pandas. No age- or sex- related differences were observed in concentrations of the fluorochemicals in panda sera. Greater concentrations of the fluorochemicals were found for those individuals collected from zoos near urbanized or industrialized areas than for other areas. These data combined with other reported data suggest that there are large differences in distribution of perfluorinated compounds in terrestrial animals.

  20. VLT/FLAMES spectroscopy of red giant branch stars in the Carina dwarf spheroidal galaxy

    NARCIS (Netherlands)

    Lemasle, B.; Hill, V.; Tolstoy, E.; Venn, K. A.; Shetrone, M. D.; Irwin, M. J.; de Boer, T. J. L.; Starkenburg, E.; Salvadori, S.

    Context. The ages of individual red giant branch stars can range from 1 Gyr old to the age of the Universe, and it is believed that the abundances of most chemical elements in their photospheres remain unchanged with time (those that are not affected by the first dredge-up). This means that they

  1. Fast core rotation in red-giant stars as revealed by gravity-dominated mixed modes

    NARCIS (Netherlands)

    Beck, P.G.; Montalban, J.; Kallinger, T.; De Ridder, J.; Aerts, C.; García, R.A.; Hekker, S.; Dupret, M.-A.; Mosser, B.; Eggenberger, P.; Stello, D.; Elsworth, Y.; Frandsen, S.; Carrier, F.; Hillen, M.; Gruberbauer, M.; Christensen-Dalsgaard, J.; Miglio, A.; Valentini, M.; Bedding, T.R.; Kjeldsen, H.; Girouard, F.R.; Hall, J.R.; Ibrahim, K.A.

    2012-01-01

    When the core hydrogen is exhausted during stellar evolution, the central region of a star contracts and the outer envelope expands and cools, giving rise to a red giant. Convection takes place over much of the star's radius. Conservation of angular momentum requires that the cores of these stars

  2. A simple model to describe intrinsic stellar noise for exoplanet detection around red giants

    DEFF Research Database (Denmark)

    North, Thomas S. H.; Chaplin, William J.; Gilliland, Ronald L.

    2017-01-01

    In spite of the huge advances in exoplanet research provided by the NASA Kepler Mission, there remain only a small number of transit detections around evolved stars. Here, we present a reformulation of the noise properties of red-giant stars, where the intrinsic stellar granulation and the stella...

  3. Curve-of-growth analysis of a red giant in the globular cluster M13

    International Nuclear Information System (INIS)

    Griffin, R.

    1979-01-01

    A coude spectrogram of a red giant (L973) in the globular cluster M13 is analysed, with respect to α Boo, by the differential curve-of-growth technique. The overall metal abundance is found to be approximately one-tenth of that of α Boo, or one-fortieth that of the Sun. (author)

  4. Survival of the Jovian planets with the Sun a red giant

    International Nuclear Information System (INIS)

    Vila, S.C.

    1985-01-01

    The survival of the Jovian planets and their satellites as the Sun becomes a Red Giant is considered. It is found that the Jovian planets would not lose any matter - not even hydrogen. The satellites would lose their gaseous or volatile envelopes. Their rocky cores would resist melting and survive. Both the planets and the satellites would be unsuited to support human life. (Auth.)

  5. Survival of the Jovian planets with the Sun a red giant

    Energy Technology Data Exchange (ETDEWEB)

    Vila, S C

    1985-12-01

    The survival of the Jovian planets and their satellites as the Sun becomes a Red Giant is considered. It is found that the Jovian planets would not lose any matter - not even hydrogen. The satellites would lose their gaseous or volatile envelopes. Their rocky cores would resist melting and survive. Both the planets and the satellites would be unsuited to support human life. (Auth.).

  6. DEEP MIXING IN EVOLVED STARS. II. INTERPRETING Li ABUNDANCES IN RED GIANT BRANCH AND ASYMPTOTIC GIANT BRANCH STARS

    International Nuclear Information System (INIS)

    Palmerini, S.; Busso, M.; Maiorca, E.; Cristallo, S.; Abia, C.; Uttenthaler, S.; Gialanella, L.

    2011-01-01

    We reanalyze the problem of Li abundances in red giants of nearly solar metallicity. After outlining the problems affecting our knowledge of the Li content in low-mass stars (M ≤ 3 M sun ), we discuss deep-mixing models for the red giant branch stages suitable to account for the observed trends and for the correlated variations of the carbon isotope ratio; we find that Li destruction in these phases is limited to masses below about 2.3 M sun . Subsequently, we concentrate on the final stages of evolution for both O-rich and C-rich asymptotic giant branch (AGB) stars. Here, the constraints on extra-mixing phenomena previously derived from heavier nuclei (from C to Al), coupled to recent updates in stellar structure models (including both the input physics and the set of reaction rates used), are suitable to account for the observations of Li abundances below A(Li) ≡ log ε(Li) ≅ 1.5 (and sometimes more). Also, their relations with other nucleosynthesis signatures of AGB phases (like the abundance of F, and the C/O and 12 C/ 13 C ratios) can be explained. This requires generally moderate efficiencies (M-dot -6 M sun yr -1 ) for non-convective mass transport. At such rates, slow extra mixing does not remarkably modify Li abundances in early AGB phases; on the other hand, faster mixing encounters a physical limit in destroying Li, set by the mixing velocity. Beyond this limit, Li starts to be produced; therefore, its destruction on the AGB is modest. Li is then significantly produced by the third dredge up. We also show that effective circulation episodes, while not destroying Li, would easily bring the 12 C/ 13 C ratios to equilibrium, contrary to the evidence in most AGB stars, and would burn F beyond the limits shown by C(N) giants. Hence, we do not confirm the common idea that efficient extra mixing drastically reduces the Li content of C stars with respect to K-M giants. This misleading appearance is induced by biases in the data, namely: (1) the difficulty

  7. Seismic probing of the first dredge-up event through the eccentric red-giant and red-giant spectroscopic binary KIC 9163796. How different are red-giant stars with a mass ratio of 1.015?

    Science.gov (United States)

    Beck, P. G.; Kallinger, T.; Pavlovski, K.; Palacios, A.; Tkachenko, A.; Mathis, S.; García, R. A.; Corsaro, E.; Johnston, C.; Mosser, B.; Ceillier, T.; do Nascimento, J.-D.; Raskin, G.

    2018-04-01

    Context. Binaries in double-lined spectroscopic systems (SB2) provide a homogeneous set of stars. Differences of parameters, such as age or initial conditions, which otherwise would have strong impact on the stellar evolution, can be neglected. The observed differences are determined by the difference in stellar mass between the two components. The mass ratio can be determined with much higher accuracy than the actual stellar mass. Aim. In this work, we aim to study the eccentric binary system KIC 9163796, whose two components are very close in mass and both are low-luminosity red-giant stars. Methods: We analysed four years of Kepler space photometry and we obtained high-resolution spectroscopy with the Hermes instrument. The orbital elements and the spectra of both components were determined using spectral disentangling methods. The effective temperatures, and metallicities were extracted from disentangled spectra of the two stars. Mass and radius of the primary were determined through asteroseismology. The surface rotation period of the primary is determined from the Kepler light curve. From representative theoretical models of the star, we derived the internal rotational gradient, while for a grid of models, the measured lithium abundance is compared with theoretical predictions. Results: From seismology the primary of KIC 9163796 is a star of 1.39 ± 0.06 M⊙, while the spectroscopic mass ratio between both components can be determined with much higher precision by spectral disentangling to be 1.015 ± 0.005. With such mass and a difference in effective temperature of 600 K from spectroscopy, the secondary and primary are, respectively, in the early and advanced stage of the first dredge-up event on the red-giant branch. The period of the primary's surface rotation resembles the orbital period within ten days. The radial rotational gradient between the surface and core in KIC 9163796 is found to be 6.9-1.0+2.0. This is a low value but not exceptional if

  8. Oscillating red giants in eclipsing binary systems: empirical reference value for asteroseismic scaling relation

    Science.gov (United States)

    Themeßl, N.; Hekker, S.; Southworth, J.; Beck, P. G.; Pavlovski, K.; Tkachenko, A.; Angelou, G. C.; Ball, W. H.; Barban, C.; Corsaro, E.; Elsworth, Y.; Handberg, R.; Kallinger, T.

    2018-05-01

    The internal structures and properties of oscillating red-giant stars can be accurately inferred through their global oscillation modes (asteroseismology). Based on 1460 days of Kepler observations we perform a thorough asteroseismic study to probe the stellar parameters and evolutionary stages of three red giants in eclipsing binary systems. We present the first detailed analysis of individual oscillation modes of the red-giant components of KIC 8410637, KIC 5640750 and KIC 9540226. We obtain estimates of their asteroseismic masses, radii, mean densities and logarithmic surface gravities by using the asteroseismic scaling relations as well as grid-based modelling. As these red giants are in double-lined eclipsing binaries, it is possible to derive their independent dynamical masses and radii from the orbital solution and compare it with the seismically inferred values. For KIC 5640750 we compute the first spectroscopic orbit based on both components of this system. We use high-resolution spectroscopic data and light curves of the three systems to determine up-to-date values of the dynamical stellar parameters. With our comprehensive set of stellar parameters we explore consistencies between binary analysis and asteroseismic methods, and test the reliability of the well-known scaling relations. For the three red giants under study, we find agreement between dynamical and asteroseismic stellar parameters in cases where the asteroseismic methods account for metallicity, temperature and mass dependence as well as surface effects. We are able to attain agreement from the scaling laws in all three systems if we use Δνref, emp = 130.8 ± 0.9 μHz instead of the usual solar reference value.

  9. Empirically Calibrated Asteroseismic Masses and Radii for Red Giants in the Kepler Fields

    Science.gov (United States)

    Pinsonneault, Marc; Elsworth, Yvonne; Silva Aguirre, Victor; Chaplin, William J.; Garcia, Rafael A.; Hekker, Saskia; Holtzman, Jon; Huber, Daniel; Johnson, Jennifer; Kallinger, Thomas; Mosser, Benoit; Mathur, Savita; Serenelli, Aldo; Shetrone, Matthew; Stello, Dennis; Tayar, Jamie; Zinn, Joel; APOGEE Team, KASC Team, APOKASC Team

    2018-01-01

    We report on the joint asteroseismic and spectroscopic properties of a sample of 6048 evolved stars in the fields originally observed by the Kepler satellite. We use APOGEE spectroscopic data taken from Data Release 13 of the Sloan Digital Sky Survey, combined with asteroseismic data analyzed by members of the Kepler Asteroseismic Science Consortium. With high statistical significance, the different pipelines do not have relative zero points that are the same as the solar values, and red clump stars do not have the same empirical relative zero points as red giants. We employ theoretically motivated corrections to the scaling relation for the large frequency spacing, and adjust the zero point of the frequency of maximum power scaling relation to be consistent with masses and radii for members of star clusters. The scatter in calibrator masses is consistent with our error estimation. Systematic and random mass errors are explicitly separated and identified. The measurement scatter, and random uncertainties, are three times larger for red giants where one or more technique failed to return a value than for targets where all five methods could do so, and this is a substantial fraction of the sample (20% of red giants and 25% of red clump stars). Overall trends and future prospects are discussed.

  10. Towards realistic modelling of spectral line formation - lessons learnt from red giants

    Science.gov (United States)

    Lind, Karin

    2015-08-01

    Many decades of quantitative spectroscopic studies of red giants have revealed much about the formation histories and interlinks between the main components of the Galaxy and its satellites. Telescopes and instrumentation are now able to deliver high-resolution data of superb quality for large stellar samples and Galactic archaeology has entered a new era. At the same time, we have learnt how simplifying physical assumptions in the modelling of spectroscopic data can bias the interpretations, in particular one-dimensional homogeneity and local thermodynamic equilibrium (LTE). I will present lessons learnt so far from non-LTE spectral line formation in 3D radiation-hydrodynamic atmospheres of red giants, the smaller siblings of red supergiants.

  11. Convective-core Overshoot and Suppression of Oscillations: Constraints from Red Giants in NGC 6811

    Energy Technology Data Exchange (ETDEWEB)

    Arentoft, T.; Brogaard, K.; Jessen-Hansen, J.; Silva Aguirre, V.; Kjeldsen, H.; Mosumgaard, J. R. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Sandquist, E. L., E-mail: toar@phys.au.dk [San Diego State University, Department of Astronomy, San Diego, CA 92182 (United States)

    2017-04-01

    Using data from the NASA spacecraft Kepler , we study solar-like oscillations in red giant stars in the open cluster NGC 6811. We determine oscillation frequencies, frequency separations, period spacings of mixed modes, and mode visibilities for eight cluster giants. The oscillation parameters show that these stars are helium-core-burning red giants. The eight stars form two groups with very different oscillation power spectra; the four stars with the lowest Δ ν values display rich sets of mixed l = 1 modes, while this is not the case for the four stars with higher Δ ν . For the four stars with lowest Δ ν , we determine the asymptotic period spacing of the mixed modes, Δ P , which together with the masses we derive for all eight stars suggest that they belong to the so-called secondary clump. Based on the global oscillation parameters, we present initial theoretical stellar modeling that indicates that we can constrain convective-core overshoot on the main sequence and in the helium-burning phase for these ∼2 M {sub ⊙} stars. Finally, our results indicate less mode suppression than predicted by recent theories for magnetic suppression of certain oscillation modes in red giants.

  12. Extra-mixing in red giant stars: Challenges for nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Palmerini, Sara; Maiorca, Enrico, E-mail: sara.pamerini@fisica.unipg.i [I.N.F.N. sezione di Perugia Dipartimento di Fisica Universita degli Studi di Perugia, via Pascoli, 06123, Perugia (Italy)

    2010-01-01

    The existence of extra-mixing phenomena has been often invoked as a possible solution for the Li-abundance puzzle in low-mass red giant stars. In particular, [1] have shown that extra-mixing phenomena induced by stellar magnetic fields can justify the surface Li enrichment as well as its depletion in low mass giants. In the framework of this model, we test here how sensitive is the Li production to the reaction rate for the {sup 7}Be electron capture, in order to establish whether the presence of intense magnetic fields can alter the Li yield.

  13. Peak Bagging of red giant stars observed by Kepler: first results with a new method based on Bayesian nested sampling

    Science.gov (United States)

    Corsaro, Enrico; De Ridder, Joris

    2015-09-01

    The peak bagging analysis, namely the fitting and identification of single oscillation modes in stars' power spectra, coupled to the very high-quality light curves of red giant stars observed by Kepler, can play a crucial role for studying stellar oscillations of different flavor with an unprecedented level of detail. A thorough study of stellar oscillations would thus allow for deeper testing of stellar structure models and new insights in stellar evolution theory. However, peak bagging inferences are in general very challenging problems due to the large number of observed oscillation modes, hence of free parameters that can be involved in the fitting models. Efficiency and robustness in performing the analysis is what may be needed to proceed further. For this purpose, we developed a new code implementing the Nested Sampling Monte Carlo (NSMC) algorithm, a powerful statistical method well suited for Bayesian analyses of complex problems. In this talk we show the peak bagging of a sample of high signal-to-noise red giant stars by exploiting recent Kepler datasets and a new criterion for the detection of an oscillation mode based on the computation of the Bayesian evidence. Preliminary results for frequencies and lifetimes for single oscillation modes, together with acoustic glitches, are therefore presented.

  14. Peak Bagging of red giant stars observed by Kepler: first results with a new method based on Bayesian nested sampling

    Directory of Open Access Journals (Sweden)

    Corsaro Enrico

    2015-01-01

    Full Text Available The peak bagging analysis, namely the fitting and identification of single oscillation modes in stars’ power spectra, coupled to the very high-quality light curves of red giant stars observed by Kepler, can play a crucial role for studying stellar oscillations of different flavor with an unprecedented level of detail. A thorough study of stellar oscillations would thus allow for deeper testing of stellar structure models and new insights in stellar evolution theory. However, peak bagging inferences are in general very challenging problems due to the large number of observed oscillation modes, hence of free parameters that can be involved in the fitting models. Efficiency and robustness in performing the analysis is what may be needed to proceed further. For this purpose, we developed a new code implementing the Nested Sampling Monte Carlo (NSMC algorithm, a powerful statistical method well suited for Bayesian analyses of complex problems. In this talk we show the peak bagging of a sample of high signal-to-noise red giant stars by exploiting recent Kepler datasets and a new criterion for the detection of an oscillation mode based on the computation of the Bayesian evidence. Preliminary results for frequencies and lifetimes for single oscillation modes, together with acoustic glitches, are therefore presented.

  15. Solar-like Oscillations in Low-luminosity Red Giants: First Results from Kepler

    DEFF Research Database (Denmark)

    Bedding, T. R.; Huber, D.; Stello, D.

    2010-01-01

    We have measured solar-like oscillations in red giants using time-series photometry from the first 34 days of science operations of the Kepler Mission. The light curves, obtained with 30 minute sampling, reveal clear oscillations in a large sample of G and K giants, extending in luminosity from t...

  16. INTERNAL ROTATION OF THE RED-GIANT STAR KIC 4448777 BY MEANS OF ASTEROSEISMIC INVERSION

    Energy Technology Data Exchange (ETDEWEB)

    Di Mauro, M. P.; Cardini, D. [INAF, IAPS Istituto di Astrofisica e Planetologia Spaziali, Roma (Italy); Ventura, R.; Paternò, L. [INAF, Astrophysical Observatory of Catania, Catania (Italy); Stello, D. [Sydney Institute for Astronomy, School of Physics, University of Sydney (Australia); Christensen-Dalsgaard, J.; Hekker, S. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Dziembowski, W. A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Beck, P. G.; De Smedt, K.; Tkachenko, A. [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven (Belgium); Bloemen, S. [Department of Astrophysics, IMAPP, Radboud University Nijmegen, P.O. Box 9010, NL-6500 GL, Nijmegen (Netherlands); Davies, G. R.; Garcia, R. A. [Laboratoire AIM, CEA/DSM-CNRS-Univ. Paris Diderot, IRFU/Sap, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Elsworth, Y. [School of Physics and Astronomy, University of Birmingham (United Kingdom); Mosser, B. [LESIA, PSL Research University, CNRS, Universitè Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, Meudon Cedex (France)

    2016-01-20

    We study the dynamics of the stellar interior of the early red-giant star KIC 4448777 by asteroseismic inversion of 14 splittings of the dipole mixed modes obtained from Kepler observations. In order to overcome the complexity of the oscillation pattern typical of red-giant stars, we present a procedure to extract the rotational splittings from the power spectrum. We find not only that the core rotates from a minimum of 8 to a maximum of 17 times faster than the surface, confirming previous inversion results generated for other red giants (Deheuvels et al.), but we also estimate the variation of the angular velocity within the helium core with a spatial resolution of 0.001R and verify the hypothesis of a sharp discontinuity in the inner stellar rotation. The results show that the entire core rotates rigidly and provide evidence for an angular velocity gradient around the base of the hydrogen-burning shell; however, we do not succeed in characterizing the rotational slope, due to the intrinsic limits of the applied techniques. The angular velocity, from the edge of the core, appears to decrease with increasing distance from the center, reaching an average value in the convective envelope of 68 ± 22 nHz. We conclude that a set of data that includes only dipolar modes is sufficient to infer quite accurately the rotation of a red giant not only in the dense core but also, with a lower level of confidence, in part of the radiative region and in the convective envelope.

  17. A photometric study of the giant red variable stars with small amplitudes

    International Nuclear Information System (INIS)

    Wisse, P.N.J.

    1979-01-01

    Three colour UBV observations of southern semiregular and irregular red variable stars are presented. Well covered light and colour curves have been obtained for ca. 40 stars. In most cases the observations span more than one cycle. A short description is given for all individual variables. The observations are accurate enough to reveal many minor irregularities in the light variation. The SRb and Lb variables define a narrow curved strip in the (U-B) - (B-V) diagram. This strip has been called the Locus of Red Variables (LRV). The (U-B) of the variables is about 0.5 magnitudes bluer than that of the K III giants. (Auth.)

  18. New red giant star in the Kepler open cluster NGC 6819

    Science.gov (United States)

    Komucyeya, E.; Abedigamba, O. P.; Jurua, E.; Anguma, S. K.

    2018-05-01

    A recent study indicated that 39 red giant stars showing solar-like oscillations were discovered in the field of Kepleropen cluster NGC 6819. The study was based on photometric distance estimates of 27 stars out of the 39. Using photometric method alone may not be adequate to confirm the membership of these stars. The stars were not previously known in literature to belong to the open cluster NGC 6819. In this study, Kepler data was used to study the membership of the 27 stars. A plot of apparent magnitude as a function of the large frequency separation, supplemented with the proper motion and radial velocity values from literature revealed KIC 5112840 to lie on the same plane with the well known members of the cluster. Echelle diagram was constructed, and the median gravity-mode period spacings (ΔP) calculated for KIC 5112840. A value of ΔP = 66.3 s was obtained, thus placing the red giant star KIC 5112840 on the Red Giant Branch stage of evolution. Our evolutionary status result using the approach in this paper is in agreement with what is in the available literature.

  19. Genetic diversity of giant clams (Tridacna spp.) and their associated Symbiodinium in the central Red Sea

    KAUST Repository

    Pappas, Melissa

    2017-05-19

    The biodiversity of the Red Sea remains relatively understudied, particularly for invertebrate taxa. Documenting present patterns of biodiversity is essential for better understanding Red Sea reef ecosystems and how these ecosystems may be impacted by stressors (such as fishing and climate change). Several species of giant clams (genus Tridacna) are reported from the Red Sea, although the majority of research effort has occurred in the Gulf of Aqaba. We investigated the genetic diversity (16S rDNA) of the Tridacna species found in the central Saudi Arabian Red Sea. We also investigated the genetic diversity (ITS rDNA) of symbiotic dinoflagellates Symbiodinium associated with these clams. Samples were collected from nine reefs on a cross-shelf gradient near Thuwal, Saudi Arabia. Two species, T. squamosa and T. maxima, were recorded, with the latter being the most abundant. Tridacna squamosina, a species recently reported in the northern Red Sea, was not found, suggesting that this species is not present or is very rare in our study region. All tridacnids sampled were found to harbor Symbiodinium grouped in Clade A, considered an opportunistic, heat-tolerant symbiont group in anemones and corals. The consistent association with Clade A Symbiodinium in central Red Sea tridacnids may reflect the consequence of adaptation to the relatively extreme conditions of the Red Sea. This study contributes to an ever-growing catalog of Red Sea biodiversity and serves as important baseline information for a region experiencing dynamic pressures.

  20. Genetic diversity of giant clams (Tridacna spp.) and their associated Symbiodinium in the central Red Sea

    KAUST Repository

    Pappas, Melissa; He, Song; Hardenstine, Royale; Kanee, Hana; Berumen, Michael L.

    2017-01-01

    The biodiversity of the Red Sea remains relatively understudied, particularly for invertebrate taxa. Documenting present patterns of biodiversity is essential for better understanding Red Sea reef ecosystems and how these ecosystems may be impacted by stressors (such as fishing and climate change). Several species of giant clams (genus Tridacna) are reported from the Red Sea, although the majority of research effort has occurred in the Gulf of Aqaba. We investigated the genetic diversity (16S rDNA) of the Tridacna species found in the central Saudi Arabian Red Sea. We also investigated the genetic diversity (ITS rDNA) of symbiotic dinoflagellates Symbiodinium associated with these clams. Samples were collected from nine reefs on a cross-shelf gradient near Thuwal, Saudi Arabia. Two species, T. squamosa and T. maxima, were recorded, with the latter being the most abundant. Tridacna squamosina, a species recently reported in the northern Red Sea, was not found, suggesting that this species is not present or is very rare in our study region. All tridacnids sampled were found to harbor Symbiodinium grouped in Clade A, considered an opportunistic, heat-tolerant symbiont group in anemones and corals. The consistent association with Clade A Symbiodinium in central Red Sea tridacnids may reflect the consequence of adaptation to the relatively extreme conditions of the Red Sea. This study contributes to an ever-growing catalog of Red Sea biodiversity and serves as important baseline information for a region experiencing dynamic pressures.

  1. Gravity mode offset and properties of the evanescent zone in red-giant stars

    Science.gov (United States)

    Hekker, S.; Elsworth, Y.; Angelou, G. C.

    2018-03-01

    Context. The wealth of asteroseismic data for red-giant stars and the precision with which these data have been observed over the last decade calls for investigations to further understand the internal structures of these stars. Aim. The aim of this work is to validate a method to measure the underlying period spacing, coupling term, and mode offset of pure gravity modes that are present in the deep interiors of red-giant stars. We subsequently investigate the physical conditions of the evanescent zone between the gravity mode cavity and the pressure mode cavity. Methods: We implement an alternative mathematical description compared to what is used in the literature to analyse observational data and to extract the underlying physical parameters that determine the frequencies of mixed modes. This description takes the radial order of the modes explicitly into account, which reduces its sensitivity to aliases. Additionally, and for the first time, this method allows us to constrain the gravity mode offset ɛg for red-giant stars. Results: We find that this alternative mathematical description allows us to determine the period spacing ΔΠ and the coupling term q for the dipole modes within a few percent of values found in the literature. Additionally, we find that ɛg varies on a star-by-star basis and should not be kept fixed in the analysis. Furthermore, we find that the coupling factor is logarithmically related to the physical width of the evanescent region normalised by the radius at which the evanescent zone is located. Finally, the local density contrast at the edge of the core of red-giant branch models shows a tentative correlation with the offset ɛg. Conclusions: We are continuing to exploit the full potential of the mixed modes to investigate the internal structures of red-giant stars; in this case we focus on the evanescent zone. It remains, however, important to perform comparisons between observations and models with great care as the methods employed

  2. On the observational characteristics of lithium-enhanced giant stars in comparison with normal red giants†

    Science.gov (United States)

    Takeda, Yoichi; Tajitsu, Akito

    2017-08-01

    While lithium is generally deficient in the atmosphere of evolved giant stars because of the efficient mixing-induced dilution, a small fraction of red giants show unusually strong Li lines indicative of conspicuous abundance excess. With the aim of shedding light on the origin of these peculiar stars, we carried out a spectroscopic study on the observational characteristics of 20 selected bright giants already known to be Li-rich from past studies, in comparison with the reference sample of a large number of normal late G-early K giants. Special attention was paid to clarifying any difference between the two samples from a comprehensive point of view (i.e., with respect to stellar parameters, rotation, activity, kinematic properties, 6Li/7Li ratio, and the abundances of Li, Be, C, O, Na, S, and Zn). Our sample stars are roughly divided into a “bump/clump group” and a “luminous group” according to their positions on the HR diagram. Regarding the former group [1.5 ≲ log (L/L⊙) ≲ 2 and M ∼ 1.5-3 M⊙], Li-enriched giants and normal giants appear practically similar in almost all respects except for Li, suggesting that surface Li enhancement in this group may be a transient episode which normal giants undergo at certain evolutionary stages in their lifetime. Meanwhile, those Li-rich giants belonging to the latter group [log (L/L⊙) ∼ 3 and M ∼ 3-5 M⊙] appear more anomalous in the sense that they tend to show higher rotation as well as higher activity, and that their elemental abundances (especially those derived from high-excitation lines) are apt to show apparent overabundances, though this might be due to a spurious effect reflecting the difficulty of abundance derivation in stars of higher rotation and activity. Our analysis confirmed considerable Be deficiency as well as absence of 6Li as the general characteristics of Li-rich giants under study, which implies that engulfment of planets is rather unlikely for the origin of Li-enrichment.

  3. PLANET ENGULFMENT BY ∼1.5-3 Msun RED GIANTS

    International Nuclear Information System (INIS)

    Kunitomo, M.; Ikoma, M.; Sato, B.; Ida, S.; Katsuta, Y.

    2011-01-01

    Recent radial-velocity surveys for GK clump giants have revealed that planets also exist around ∼1.5-3 M sun stars. However, no planets have been found inside 0.6 AU around clump giants, in contrast to solar-type main-sequence stars, many of which harbor short-period planets such as hot Jupiters. In this study, we examine the possibility that planets were engulfed by host stars evolving on the red-giant branch (RGB). We integrate the orbital evolution of planets in the RGB and helium-burning phases of host stars, including the effects of stellar tide and stellar mass loss. Then we derive the critical semimajor axis (or the survival limit) inside which planets are eventually engulfed by their host stars after tidal decay of their orbits. Specifically, we investigate the impact of stellar mass and other stellar parameters on the survival limit in more detail than previous studies. In addition, we make detailed comparisons with measured semimajor axes of planets detected so far, which no previous study has done. We find that the critical semimajor axis is quite sensitive to stellar mass in the range between 1.7 and 2.1 M sun , which suggests a need for careful comparison between theoretical and observational limits of the existence of planets. Our comparison demonstrates that all planets orbiting GK clump giants that have been detected are beyond the survival limit, which is consistent with the planet-engulfment hypothesis. However, on the high-mass side (>2.1M sun ), the detected planets are orbiting significantly far from the survival limit, which suggests that engulfment by host stars may not be the main reason for the observed lack of short-period giant planets. To confirm our conclusion, the detection of more planets around clump giants, especially with masses ∼> 2.5M sun , is required.

  4. Giant negative photoresistance of ZnO single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Barzola-Quiquia, Jose; Esquinazi, Pablo [Division of Superconductivity and Magnetism, University of Leipzig (Germany); Heluani, Silvia [Laboratorio de Fisica del Solido, FCEyT, Universidad Nacional de Tucuman, 4000 S. M. de Tucuman (Argentina); Villafuerte, Manuel [Dept. de Fisica, FCEyT, Universidad Nacional de Tucuman (Argentina); CONICET, Tucuman (Argentina); Poeppl, Andreas [Division of Magnetic Resonance of Complex Quantum Solids, University of Leipzig, D-04103 Leipzig (Germany)

    2011-07-01

    ZnO is a wide band gap semiconductor exhibiting the largest charge-carrier mobility among oxides. ZnO is a material with potential applications for short-wavelength optoelectronic devices, as a blue light emitting diodes and in spintronics. In this contribution we have measured the temperature dependence (30 K < T < 300 K) of the electrical resistance of ZnO single crystals prepared by hydrothermal method in darkness and under the influence of light in the ultraviolet range. The resistance decreases several orders of magnitude at temperatures T < 200 K after illumination. Electron paramagnetic resonance studies under illumination reveal that the excitation of Li acceptor impurities is the origin for the giant negative photoresistance effect. Permanent photoresistance effect is also observed, which remains many hours after leaving the crystal in darkness.

  5. Calibrating the Near-Infrared Tip of the Red Giant Branch with Multiwavelength Photometry

    Science.gov (United States)

    Durbin, Meredith

    2017-08-01

    The near-infrared (NIR) tip of the red giant branch (TRGB) shows outstanding promise as a distance indicator. In the JWST era, the NIR-TRGB will bridge the gap from local geometric parallax (with Gaia) out to the low-velocity Hubble flow in a single step, in all types of galaxies. However, there currently exist several impediments to JWST's using the TRGB to full advantage. Dalcanton et al. (2012) presented the most comprehensive dataset available for calibrating the TRGB absolute magnitude, with optical and NIR coverage of 23 nearby dwarf and spiral galaxies spanning a wide range of ages and metallicities. However, subtle offsets between this dataset, theoretical models, and globular clusters raise concerns about the calibration.We propose to perform a complete re-reduction and re-analysis of this dataset. We have developed a pipeline that leverages simultaneous fitting of optical and NIR data to produce NIR photometry of higher quality and completeness, with up to 1.5 mag greater depth than can be achieved with the NIR alone. With this added depth, improvements in photometric precision, and updated WFC3/IR PSFs and flux calibration, we will derive uniform, precise, and accurate NIR TRGB measurements, with which we will be able to resolve standing issues with the TRGB color-absolute magnitude relation and its behavior with changing star-formation histories. This work will lay the groundwork for extending the TRGB distance scale out to at least 37 Mpc with JWST. We will release the resulting 4-filter optical-NIR photometry as HLSPs for use by the community before the launch of JWST, to serve as a resource for proposing for stellar population observations in the NIR.

  6. Asteroseismology of Red-Giant Stars: Mixed Modes, Differential Rotation, and Eccentric Binaries

    Science.gov (United States)

    Beck, Paul G.

    2013-12-01

    Astronomers are aware of rotation in stars since Galileo Galilei attributed the movement of sunspots to rotation of the Sun in 1613. In contrast to the Sun, whose surface can be resolved by small telescopes or even the (protected) eye, we detect stars as point sources with no spatial information. Numerous techniques have been developed to derive information about stellar rotation. Unfortunately, most observational data allow only for the surface rotational rate to be inferred. The internal rotational profile, which has a great effect on the stellar structure and evolution, remains hidden below the top layers of the star - the essential is hidden to the eyes. Asteroseismology allows us to "sense" indirectly deep below the stellar surface. Oscillations that propagate through the star provide information about the deep stellar interiors while they also distort the stellar surface in characteristic patterns leading to detectable brightness or velocity variations. Also, certain oscillation modes are sensitive to internal rotation and carry information on how the star is spinning deep inside. Thanks to the unprecedented quality of NASA's space telescope Kepler, numerous detailed observations of stars in various evolutionary stages are available. Such high quality data allow that for many stars, rotation can not only be constrained from surface rotation, but also investigated through seismic studies. The work presented in this thesis focuses on the oscillations and internal rotational gradient of evolved single and binary stars. It is shown that the seismic analysis can reach the cores of oscillating red-giant stars and that these cores are rapidly rotating, while nested in a slowly rotating convective envelope.

  7. Far-ultraviolet fluorescence of carbon monoxide in the red giant Arcturus

    International Nuclear Information System (INIS)

    Ayres, T.R.; Moos, H.W.; Linsky, J.L.

    1981-01-01

    We present evidence that many of the weak features observed with the International Ultraviolet Explorer (IUE) in the far-ultraviolet (1150--2000 A) spectrum of the archetype red giant Arcturus (K2 III) are A--X fourth positive bands of carbon monoxide excited by chromospheric emissions of O I, C I, and H I. The appearance of fluorescent CO bands near the wavelengths of commonly used indicators of high-temperature (T>2 x 10 4 K) plasma, such as C II lambda1335 and C IV lambda1548, introduces a serious ambiguity in diagnosing the presence of hot material in the outer atmospheres of the cool giants by means of low-dispersion IUE spectra

  8. CHEMICAL ABUNDANCES IN FIELD RED GIANTS FROM HIGH-RESOLUTION H-BAND SPECTRA USING THE APOGEE SPECTRAL LINELIST

    International Nuclear Information System (INIS)

    Smith, Verne V.; Cunha, Katia; Shetrone, Matthew D.; Meszaros, Szabolcs; Allende Prieto, Carlos; Bizyaev, Dmitry; Garcìa Pèrez, Ana; Majewski, Steven R.; Schiavon, Ricardo; Holtzman, Jon; Johnson, Jennifer A.

    2013-01-01

    High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory Fourier transform spectrometer, are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the Sloan Digital Sky Survey III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. The red giant sample studied here was chosen to probe which chemical elements can be derived reliably from the H-band APOGEE spectral region. These red giants consist of two K-giants (α Boo and μ Leo), two M-giants (β And and δ Oph), and one thermally pulsing asymptotic giant branch (TP-AGB) star of spectral type MS (HD 199799). Measured chemical abundances include the cosmochemically important isotopes 12 C, 13 C, 14 N, and 16 O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. The K and M giants exhibit the abundance signature of the first dredge-up of CN-cycle material, while the TP-AGB star shows clear evidence of the addition of 12 C synthesized during 4 He-burning thermal pulses and subsequent third dredge-up. A comparison of the abundances derived here with published values for these stars reveals consistent results to ∼0.1 dex. The APOGEE spectral region and linelist is thus well suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants via high-resolution spectroscopy.

  9. CHEMICAL ABUNDANCES IN FIELD RED GIANTS FROM HIGH-RESOLUTION H-BAND SPECTRA USING THE APOGEE SPECTRAL LINELIST

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Verne V.; Cunha, Katia [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Shetrone, Matthew D. [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Meszaros, Szabolcs; Allende Prieto, Carlos [Instituto d' Astrofisica de Canarias, E-38205, La Laguna, Tenerife (Spain); Bizyaev, Dmitry [Apache Point Observatory, Sunspot, NM 88349 (United States); Garcia Perez, Ana; Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Schiavon, Ricardo [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5UX (United Kingdom); Holtzman, Jon [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Johnson, Jennifer A., E-mail: vsmith@noao.edu [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)

    2013-03-01

    High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory Fourier transform spectrometer, are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the Sloan Digital Sky Survey III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. The red giant sample studied here was chosen to probe which chemical elements can be derived reliably from the H-band APOGEE spectral region. These red giants consist of two K-giants ({alpha} Boo and {mu} Leo), two M-giants ({beta} And and {delta} Oph), and one thermally pulsing asymptotic giant branch (TP-AGB) star of spectral type MS (HD 199799). Measured chemical abundances include the cosmochemically important isotopes {sup 12}C, {sup 13}C, {sup 14}N, and {sup 16}O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. The K and M giants exhibit the abundance signature of the first dredge-up of CN-cycle material, while the TP-AGB star shows clear evidence of the addition of {sup 12}C synthesized during {sup 4}He-burning thermal pulses and subsequent third dredge-up. A comparison of the abundances derived here with published values for these stars reveals consistent results to {approx}0.1 dex. The APOGEE spectral region and linelist is thus well suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants via high-resolution spectroscopy.

  10. Serosurvey of ex situ giant pandas (Ailuropoda melanoleuca) and red pandas (Ailurus fulgens) in China with implications for species conservation.

    Science.gov (United States)

    Loeffler, I Kati; Howard, JoGayle; Montali, Richard J; Hayek, Lee-Ann; Dubovi, Edward; Zhang, Zhihe; Yan, Qigui; Guo, Wanzhu; Wildt, David E

    2007-12-01

    Conservation strategies for the giant panda (Ailuropoda melanoleuca) include the development of a self-sustaining ex situ population. This study examined the potential significance of infectious pathogens in giant pandas ex situ. Serologic antibody titers against canine distemper virus (CDV), canine parvovirus (CPV), canine adenovirus (CAV), canine coronavirus (CCV), canine herpesvirus, canine parainfluenza virus (CPIV), Toxoplasma gondii, Neospora caninum, and Leptospira interrogans were measured in 44 samples taken from 19 giant pandas between 1998 and 2003 at the Chengdu Research Base of Giant Panda Breeding in Sichuan, China. Seroassays also included samples obtained in 2003 from eight red pandas (Ailurus fulgens) housed at the same institution. All individuals had been vaccinated with a Chinese canine vaccine that included modified live CDV, CPV, CAV, CCV, and CPIV. Positive antibody titers were found only against CDV, CPV, and T. gondii. Sera were negative for antibodies against the other six pathogens. Results indicate that the quality of the vaccine may not be reliable and that it should not be considered protective or safe in giant pandas and red pandas. Positive antibody titers against T. gondii were found in seven of the 19 giant pandas. The clinical, subclinical, or epidemiologic significance of infection with these pathogens via natural exposure or from modified live vaccines in giant pandas is unknown. Research in this area is imperative to sustaining a viable population of giant pandas and other endangered species.

  11. Pulsating red giants and supergiants as probes of galaxy formation and evolution

    Science.gov (United States)

    Theodorus van Loon, Jacco; Javadi, Atefeh; Khosroshahi, Habib; Rezaei, Sara; Golshan, Roya; Saberi, Maryam

    2015-08-01

    We have developed new techniques to use pulsating red giant and supergiants stars to reconstruct the star formation history of galaxies over cosmological time, as well as using them to map the dust production across their host galaxies. We describe the large programme on the Local Group spiral galaxy Triangulum (M33), which we have monitored at near-infrared wavelengths for several years using the United Kingdom InfraRed Telescope in Hawai'i. We outline the methodology and present the results for the central square kiloparsec (Javadi et al. 2011a,b, 2013) and - fresh from the press - the disc of M33 (Javadi et al. 2015, and in preparation). We also describe the results from our application of this new technique to other nearby galaxies: the Magellanic Clouds (published in Rezaei et al. 2014), the dwarf galaxies NGC 147 and 185 (Golshan et al. in preparation), and Centaurus A.

  12. Mass loss from red giants - A simple evolutionary model for NGC 7027

    Science.gov (United States)

    Jura, M.

    1984-01-01

    NGC 7027 is a young planetary nebula with the remnants of a red giant circumstellar envelope surrounding the central, ionized region. By comparing the outer molecular envelope with the inner ionized material, it is argued that the mass loss rate has decreased by at least a factor of 3, and more probably by about a factor of 10, during the past 1000 years. From this result, it is argued that the luminosity of the central star has also decreased substantially during the same time, consistent with models for the rapid evolution of stars just after they evolve off the asymptotic giant branch. In this picture, the distance to NGC 7027 is less than 1300 pc. NGC 7027 was the last (and best) example of a star where apparently the momentum in the outflowing mass /M(dot)v/ is considerably greater than the momentum in the radiation field (L/c). With the above description of this object, the evidence is now strong that quite often the mass lost from late-type giants is ultimately driven to infinity by radiation pressure on grains. If M(dot)v is as large as L/c for asymptotic branch stars, then it is expected that the total amount of mass lost during this stage of evolution is of the same magnitude as the initial mass of the star, and therefore this mass loss can profoundly affect the star's ultimate fate.

  13. Survival of a brown dwarf after engulfment by a red giant star.

    Science.gov (United States)

    Maxted, P F L; Napiwotzki, R; Dobbie, P D; Burleigh, M R

    2006-08-03

    Many sub-stellar companions (usually planets but also some brown dwarfs) orbit solar-type stars. These stars can engulf their sub-stellar companions when they become red giants. This interaction may explain several outstanding problems in astrophysics but it is unclear under what conditions a low mass companion will evaporate, survive the interaction unchanged or gain mass. Observational tests of models for this interaction have been hampered by a lack of positively identified remnants-that is, white dwarf stars with close, sub-stellar companions. The companion to the pre-white dwarf AA Doradus may be a brown dwarf, but the uncertain history of this star and the extreme luminosity difference between the components make it difficult to interpret the observations or to put strong constraints on the models. The magnetic white dwarf SDSS J121209.31 + 013627.7 may have a close brown dwarf companion but little is known about this binary at present. Here we report the discovery of a brown dwarf in a short period orbit around a white dwarf. The properties of both stars in this binary can be directly observed and show that the brown dwarf was engulfed by a red giant but that this had little effect on it.

  14. HUBBLE SPACE TELESCOPE CONSTRAINTS ON THE WINDS AND ASTROSPHERES OF RED GIANT STARS

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Brian E. [Naval Research Laboratory, Space Science Division, Washington, DC 20375 (United States); Müller, Hans-Reinhard [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Harper, Graham M., E-mail: brian.wood@nrl.navy.mil [CASA, University of Colorado, Boulder, CO 80309-0389 (United States)

    2016-10-01

    We report on an ultraviolet spectroscopic survey of red giants observed by the Hubble Space Telescope , focusing on spectra of the Mg ii h and k lines near 2800 Å in order to study stellar chromospheric emission, winds, and astrospheric absorption. We focus on spectral types between K2 III and M5 III, a spectral type range with stars that are noncoronal, but possessing strong, chromospheric winds. We find a very tight relation between Mg ii surface flux and photospheric temperature, supporting the notion that all K2-M5 III stars are emitting at a basal flux level. Wind velocities ( V {sub w} ) are generally found to decrease with spectral type, with V {sub w} decreasing from ∼40 km s{sup −1} at K2 III to ∼20 km s{sup −1} at M5 III. We find two new detections of astrospheric absorption, for σ Pup (K5 III) and γ Eri (M1 III). This absorption signature had previously only been detected for α Tau (K5 III). For the three astrospheric detections, the temperature of the wind after the termination shock (TS) correlates with V {sub w} , but is lower than predicted by the Rankine–Hugoniot shock jump conditions, consistent with the idea that red giant TSs are radiative shocks rather than simple hydrodynamic shocks. A full hydrodynamic simulation of the γ Eri astrosphere is provided to explore this further.

  15. TESTING CONVECTIVE-CORE OVERSHOOTING USING PERIOD SPACINGS OF DIPOLE MODES IN RED GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Montalban, J.; Noels, A.; Dupret, M.-A.; Scuflaire, R. [Institut d' Astrophysique et Geophysique de l' Universite de Liege, Allee du six Aout, 17 B-4000 Liege (Belgium); Miglio, A. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Ventura, P. [Osservatorio Astronomico di Roma-INAF, via Frascati 33, I-00040 Monteporzio Catone, Rome (Italy)

    2013-04-01

    Uncertainties on central mixing in main-sequence (MS) and core He-burning (He-B) phases affect key predictions of stellar evolution such as late evolutionary phases, chemical enrichment, ages, etc. We propose a test of the extension of extra-mixing in two relevant evolutionary phases based on period spacing ({Delta}P) of solar-like oscillating giants. From stellar models and their corresponding adiabatic frequencies (respectively, computed with ATON and LOSC codes), we provide the first predictions of the observable {Delta}P for stars in the red giant branch and in the red clump (RC). We find (1) a clear correlation between {Delta}P and the mass of the helium core (M{sub He}); the latter in intermediate-mass stars depends on the MS overshooting, and hence it can be used to set constraints on extra-mixing during MS when coupled with chemical composition; and (2) a linear dependence of the average value of the asymptotic period spacing (({Delta}P){sub a}) on the size of the convective core during the He-B phase. A first comparison with the inferred asymptotic period spacing for Kepler RC stars also suggests the need for extra-mixing during this phase, as evinced from other observational facts.

  16. Precision Distances with the Tip of the Red Giant Branch Method

    Science.gov (United States)

    Beaton, Rachael Lynn; Carnegie-Chicago Hubble Program Team

    2018-01-01

    The Carnegie-Chicago Hubble Program aims to construct a distance ladder that utilizes old stellar populations in the outskirts of galaxies to produce a high precision measurement of the Hubble Constant that is independent of Cepheids. The CCHP uses the tip of the red giant branch (TRGB) method, which is a statistical measurement technique that utilizes the termination of the red giant branch. Two innovations combine to make the TRGB a competitive route to the Hubble Constant (i) the large-scale measurement of trigonometric parallax by the Gaia mission and (ii) the development of both precise and accurate means of determining the TRGB in both nearby (~1 Mpc) and distant (~20 Mpc) galaxies. Here I will summarize our progress in developing these standardized techniques, focusing on both our edge-detection algorithm and our field selection strategy. Using these methods, the CCHP has determined equally precise (~2%) distances to galaxies in the Local Group (< 1 Mpc) and across the Local Volume (< 20 Mpc). The TRGB is, thus, an incredibly powerful and straightforward means to determine distances to galaxies of any Hubble Type and, thus, has enormous potential for putting any number of astrophyiscal phenomena on absolute units.

  17. Habitability of super-Earth planets around other suns: models including Red Giant Branch evolution.

    Science.gov (United States)

    von Bloh, W; Cuntz, M; Schröder, K-P; Bounama, C; Franck, S

    2009-01-01

    The unexpected diversity of exoplanets includes a growing number of super-Earth planets, i.e., exoplanets with masses of up to several Earth masses and a similar chemical and mineralogical composition as Earth. We present a thermal evolution model for a 10 Earth-mass planet orbiting a star like the Sun. Our model is based on the integrated system approach, which describes the photosynthetic biomass production and takes into account a variety of climatological, biogeochemical, and geodynamical processes. This allows us to identify a so-called photosynthesis-sustaining habitable zone (pHZ), as determined by the limits of biological productivity on the planetary surface. Our model considers solar evolution during the main-sequence stage and along the Red Giant Branch as described by the most recent solar model. We obtain a large set of solutions consistent with the principal possibility of life. The highest likelihood of habitability is found for "water worlds." Only mass-rich water worlds are able to realize pHZ-type habitability beyond the stellar main sequence on the Red Giant Branch.

  18. An Extremely Lithium-rich Bright Red Giant in the Globular Cluster M3

    Science.gov (United States)

    Kraft, Robert P.; Peterson, Ruth C.; Guhathakurta, Puragra; Sneden, Christopher; Fulbright, Jon P.; Langer, G. Edward

    1999-06-01

    We have serendipitously discovered an extremely lithium-rich star on the red giant branch of the globular cluster M3 (NGC 5272). An echelle spectrum obtained with the Keck I High-Resolution Echelle Spectrograph reveals a Li I λ6707 resonance doublet of 520 mÅ equivalent width, and our analysis places the star among the most Li-rich giants known: logε(Li)~=+3.0. We determine the elemental abundances of this star, IV-101, and three other cluster members of similar luminosity and color and conclude that IV-101 has abundance ratios typical of giants in M3 and M13 that have undergone significant mixing. We discuss mechanisms by which a low-mass star may be so enriched in Li, focusing on the mixing of material processed by the hydrogen-burning shell just below the convective envelope. While such enrichment could conceivably happen only rarely, it may in fact regularly occur during giant-branch evolution but be rarely detected because of rapid subsequent Li depletion. Based on observations obtained with the Keck I Telescope of the W. M. Keck Observatory, which is operated by the California Association for Research in Astronomy (CARA), Inc., on behalf of the University of California and the California Institute of Technology. This Letter is dedicated to the memory of our beloved colleague Ed Langer, who died after a brief illness on February 16, 1999. Ed brought a unique theoretical perspective to our globular cluster abundance studies. His career truly embodied the academic ideals of inspiration in both teaching and research. He made friends wherever he traveled, and was an inspiration to students. We will miss him greatly.

  19. Solar-like oscillations in red giants observed with Kepler: comparison of global oscillation parameters from different methods

    DEFF Research Database (Denmark)

    Hekker, Saskia; Elsworth, Yvonne; De Ridder, Joris

    2011-01-01

    investigate the differences in results for global oscillation parameters of G and K red-giant stars due to different methods and definitions. We also investigate uncertainties originating from the stochastic nature of the oscillations. Methods: For this investigation we use Kepler data obtained during...... obtain results for the frequency of maximum oscillation power (ν_max) and the mean large separation () from different methods for over one thousand red-giant stars. The results for these parameters agree within a few percent and seem therefore robust to the different analysis methods and definitions...

  20. Models of red giants in the CoRoT asteroseismology fields combining asteroseismic and spectroscopic constraints

    Science.gov (United States)

    Nadège, Lagarde

    The availability of asteroseismic constraints for a large sample of red-giant stars from the CoRoT and Kepler missions paves the way for various statistical studies of the seismic properties of stellar populations. We use a detailed spectroscopic study of 19 CoRoT red-giant stars (Morel et al. 2014) to compare theoretical stellar evolution models to observations of the open cluster NGC 6633 and field stars. This study is already published in Lagarde et al. (2015)

  1. Red giants and yellow stragglers in the young open cluster NGC 2447

    Science.gov (United States)

    da Silveira, M. D.; Pereira, C. B.; Drake, N. A.

    2018-06-01

    In this work we analysed, using high-resolution spectroscopy, a sample of 12 single and 4 spectroscopic binary stars of the open cluster NGC 2447. For the single stars, we obtained atmospheric parameters and chemical abundances of Li, C, N, O, Na, Mg, Al, Ca, Si, Ti, Ni, Cr, Y, Zr, La, Ce, Nd, Eu. Rotational velocities were obtained for all the stars. The abundances of the light elements and Eu and the rotational velocities were derived using spectral synthesis technique. We obtained a mean metallicity of [Fe/H] = -0.17 ± 0.05. We found that the abundances of all elements are similar to field giants and/or giants of open clusters, even for the s-process elements, which are enhanced as in other young open clusters. We show that the spectroscopic binaries NGC 2447-26, 38, and 42 are yellow-straggler stars, of which the primary is a giant star and the secondary a main-sequence A-type star.

  2. Giant electrical power factor in single-walled chiral carbon nanotube

    International Nuclear Information System (INIS)

    Mensah, S.Y.; Allotey, F.K.A.; Mensah, N.G.; Nkrumah, G.

    2001-10-01

    Using the semiclassical approach we studied the thermoelectrical properties of single-walled chiral carbon nanotubes (SWNTs). We predict a giant electrical power factor and hence proposed the use of carbon nanotubes as thermoelements for refrigeration. (author)

  3. Modeling Radial Velocities and Eclipse Photometry of the Kepler Target KIC 4054905: an Oscillating Red Giant in an Eclipsing Binary

    Science.gov (United States)

    Benbakoura, M.; Gaulme, P.; McKeever, J.; Beck, P. G.; Jackiewicz, J.; García, R. A.

    2017-12-01

    Asteroseismology is a powerful tool to measure the fundamental properties of stars and probe their interiors. This is particularly efficient for red giants because their modes are well detectable and give information on their deep layers. However, the seismic relations used to infer the mass and radius of a star have been calibrated on the Sun. Therefore, it is crucial to assess their accuracy for red giants which are not perfectly homologous to it. We study eclipsing binaries with a giant component to test their validity. We identified 16 systems for which we intend to compare the dynamical masses and radii obtained by combined photometry and spectroscopy to the values obtained from asteroseismology. In the present work, we illustrate our approach on a system from our sample.

  4. High resolution spectroscopy of Red Giant Branch stars and the chemical evolution of the Fornax dwarf spheroidal galaxy

    NARCIS (Netherlands)

    Lemasle, B.; de Boer, T. J. L.; Hill, V.; Tolstoy, E.; Irwin, M. J.; Jablonka, P.; Venn, K.; Battaglia, G.; Starkenburg, E.; Shetrone, M.; Letarte, B.; Francois, P.; Helmi, A.; Primas, F.; Kaufer, A.; Szeifert, T.; Ballet, J.; Martins, F.; Bournaud, F.; Monier, R.; Reylé, C.

    2014-01-01

    From VLT-FLAMES high-resolution spectra, we determine the abundances of several α, iron-peak and neutron-capture elements in 47 Red Giant Branch stars in the Fornax dwarf spheroidal galaxy. We confirm that SNe Ia started to contribute to the chemical enrichment of Fornax at [Fe/H] between --2.0 and

  5. Probing the core structure and evolution of red giants using gravity-dominated mixed modes observed with Kepler

    NARCIS (Netherlands)

    Mosser, B.; Goupil, M.J.; Belkacem, K.; Michel, E.; Stello, D.; Marques, J.P.; Elsworth, Y.; Barban, C.; Beck, P.G.; Bedding, T.R.; De Ridder, J.; García, R.A.; Hekker, S.; Kallinger, T.; Samadi, R.; Stumpe, M.C.; Barclay, T.; Burke, C.J.

    2012-01-01

    Context. There are now more than 22 months of long-cadence data available for thousands of red giants observed with the Kepler space mission. Consequently, we are able to clearly resolve fine details in their oscillation spectra and see many components of the mixed modes that probe the stellar core.

  6. The effects of age on red giant metallicities derived from the near-infrared CaII triplet

    NARCIS (Netherlands)

    Cole, AA; Smecker-Hane, TA; Tolstoy, E; Bosler, TL; Gallagher, JS

    2004-01-01

    We have obtained spectra with a resolution of similar to2.5 Angstrom in the region of approximate to7500-9500 Angstrom for 116 red giants in five galactic globular clusters and six old open clusters (five with published metallicities and one previously unmeasured). The signal-to-noise (S/N) ratio

  7. Mass and age of red giant branch stars observed with LAMOST and Kepler

    Science.gov (United States)

    Wu, Yaqian; Xiang, Maosheng; Bi, Shaolan; Liu, Xiaowei; Yu, Jie; Hon, Marc; Sharma, Sanjib; Li, Tanda; Huang, Yang; Liu, Kang; Zhang, Xianfei; Li, Yaguang; Ge, Zhishuai; Tian, Zhijia; Zhang, Jinghua; Zhang, Jianwei

    2018-04-01

    Obtaining accurate and precise masses and ages for large numbers of giant stars is of great importance for unraveling the assemblage history of the Galaxy. In this paper, we estimate masses and ages of 6940 red giant branch (RGB) stars with asteroseismic parameters deduced from Kepler photometry and stellar atmospheric parameters derived from LAMOST spectra. The typical uncertainties of mass is a few per cent, and that of age is ˜20 per cent. The sample stars reveal two separate sequences in the age-[α/Fe] relation - a high-α sequence with stars older than ˜8 Gyr and a low-α sequence composed of stars with ages ranging from younger than 1 Gyr to older than 11 Gyr. We further investigate the feasibility of deducing ages and masses directly from LAMOST spectra with a machine learning method based on kernel based principal component analysis, taking a sub-sample of these RGB stars as a training data set. We demonstrate that ages thus derived achieve an accuracy of ˜24 per cent. We also explored the feasibility of estimating ages and masses based on the spectroscopically measured carbon and nitrogen abundances. The results are quite satisfactory and significantly improved compared to the previous studies.

  8. High-resolution Spectroscopic Abundances of Red Giant Branch Stars in NGC 6681

    Energy Technology Data Exchange (ETDEWEB)

    O’Malley, Erin M.; Chaboyer, Brian [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03784 (United States); Knaizev, Alexei [South African Astronomical Observatory, Cape Town (South Africa); McWilliam, Andrew [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2017-09-01

    We obtain high-resolution spectra of nine red giant branch stars in NGC 6681 and perform the first detailed abundance analysis of stars in this cluster. We confirm cluster membership for these stars based on consistent radial velocities of 214.5 ± 3.7 km s{sup −1} and find a mean [Fe/H] = −1.63 ± 0.07 dex and [ α /Fe] = 0.42 ± 0.11 dex. Additionally, we confirm the existence of a Na–O anti-correlation in NGC 6681 and identify two populations of stars with unique abundance trends. With the use of HST photometry from Sarajedini et al. and Piotto et al. we are able to identify these two populations as discrete sequences in the cluster CMD. Although we cannot confirm the nature of the polluter stars responsible for the abundance differences in these populations, these results do help put constraints on possible polluter candidates.

  9. IS DUST FORMING ON THE RED GIANT BRANCH IN 47 Tuc?

    International Nuclear Information System (INIS)

    Boyer, Martha L.; Gordon, Karl D.; Meixner, Margaret; Sewilo, Marta; Shiao, Bernie; Van Loon, Jacco Th.; McDonald, Iain; Babler, Brian; Bracker, Steve; Meade, Marilyn; Block, Miwa; Engelbracht, Charles; Misselt, Karl; Hora, Joe; Indebetouw, Remy; Whitney, Barbara

    2010-01-01

    Using Spitzer Infrared Array Camera (IRAC) observations from the SAGE-SMC Legacy program and archived Spitzer IRAC data, we investigate dust production in 47 Tuc, a nearby massive Galactic globular cluster. A previous study detected infrared excess, indicative of circumstellar dust, in a large population of stars in 47 Tuc, spanning the entire red giant branch (RGB). We show that those results suffered from effects caused by stellar blending and imaging artifacts and that it is likely that no stars below ∼1 mag from the tip of the RGB are producing dust. The only stars that appear to harbor dust are variable stars, which are also the coolest and most luminous stars in the cluster.

  10. A BAYESIAN APPROACH TO LOCATING THE RED GIANT BRANCH TIP MAGNITUDE. II. DISTANCES TO THE SATELLITES OF M31

    Energy Technology Data Exchange (ETDEWEB)

    Conn, A. R.; Parker, Q. A.; Zucker, D. B. [Department of Physics and Astronomy, Macquarie University, NSW 2109 (Australia); Ibata, R. A.; Martin, N. F. [Observatoire Astronomique, Universite de Strasbourg, CNRS, F-67000 Strasbourg (France); Lewis, G. F. [Sydney Institute for Astronomy, School of Physics, A28, University of Sydney, Sydney, NSW 2006 (Australia); McConnachie, A. W. [NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, British Columbia V9E 2E7 (Canada); Irwin, M. J.; Chapman, S. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Tanvir, N. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Fardal, M. A. [University of Massachusetts, Department of Astronomy, LGRT 619-E, 710 N. Pleasant Street, Amherst, MA 01003-9305 (United States); Ferguson, A. M. N. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Valls-Gabaud, D. [Observatoire de Paris, LERMA, 61 Avenue de l' Observatoire, F-75014 Paris (France)

    2012-10-10

    In 'A Bayesian Approach to Locating the Red Giant Branch Tip Magnitude (Part I)', a new technique was introduced for obtaining distances using the tip of the red giant branch (TRGB) standard candle. Here we describe a useful complement to the technique with the potential to further reduce the uncertainty in our distance measurements by incorporating a matched-filter weighting scheme into the model likelihood calculations. In this scheme, stars are weighted according to their probability of being true object members. We then re-test our modified algorithm using random-realization artificial data to verify the validity of the generated posterior probability distributions (PPDs) and proceed to apply the algorithm to the satellite system of M31, culminating in a three-dimensional view of the system. Further to the distributions thus obtained, we apply a satellite-specific prior on the satellite distances to weight the resulting distance posterior distributions, based on the halo density profile. Thus in a single publication, using a single method, a comprehensive coverage of the distances to the companion galaxies of M31 is presented, encompassing the dwarf spheroidals Andromedas I-III, V, IX-XXVII, and XXX along with NGC 147, NGC 185, M33, and M31 itself. Of these, the distances to Andromedas XXIV-XXVII and Andromeda XXX have never before been derived using the TRGB. Object distances are determined from high-resolution tip magnitude posterior distributions generated using the Markov Chain Monte Carlo technique and associated sampling of these distributions to take into account uncertainties in foreground extinction and the absolute magnitude of the TRGB as well as photometric errors. The distance PPDs obtained for each object both with and without the aforementioned prior are made available to the reader in tabular form. The large object coverage takes advantage of the unprecedented size and photometric depth of the Pan-Andromeda Archaeological Survey

  11. Detecting Solar-like Oscillations in Red Giants with Deep Learning

    Science.gov (United States)

    Hon, Marc; Stello, Dennis; Zinn, Joel C.

    2018-05-01

    Time-resolved photometry of tens of thousands of red giant stars from space missions like Kepler and K2 has created the need for automated asteroseismic analysis methods. The first and most fundamental step in such analysis is to identify which stars show oscillations. It is critical that this step be performed with no, or little, detection bias, particularly when performing subsequent ensemble analyses that aim to compare the properties of observed stellar populations with those from galactic models. However, an efficient, automated solution to this initial detection step still has not been found, meaning that expert visual inspection of data from each star is required to obtain the highest level of detections. Hence, to mimic how an expert eye analyzes the data, we use supervised deep learning to not only detect oscillations in red giants, but also to predict the location of the frequency at maximum power, ν max, by observing features in 2D images of power spectra. By training on Kepler data, we benchmark our deep-learning classifier against K2 data that are given detections by the expert eye, achieving a detection accuracy of 98% on K2 Campaign 6 stars and a detection accuracy of 99% on K2 Campaign 3 stars. We further find that the estimated uncertainty of our deep-learning-based ν max predictions is about 5%. This is comparable to human-level performance using visual inspection. When examining outliers, we find that the deep-learning results are more likely to provide robust ν max estimates than the classical model-fitting method.

  12. Ransom, Religion, and Red Giants: C.S. Lewis and Fred Hoyle

    Science.gov (United States)

    Larsen, Kristine

    2010-01-01

    Famed fantasy writer C.S. Lewis (1898-1963) was known to friends as a well-read astronomy aficionado. However, this medieval scholar and Christian apologist embraced a pre-Copernican universe (with its astrological overtones) in his Chronicles of Narnia series and defended the beauty and relevance of the geocentric model in his final academic work, "The Discarded Image". In the "Ransom Trilogy” ("Out of the Silent Planet", "Perelandra", and "That Hideous Strength") philologist Ransom (loosely based on Lewis's close friend J.R.R. Tolkien) travels to Lewis's visions of Mars and Venus, where he interacts with intelligent extraterrestrials, battles with evil scientists, and aids in the continuation of extraterrestrial Christian values. In the final book, Ransom is joined by a handful of colleagues in open warfare against the satanic N.I.C.E. (National Institute for Coordinated Experiments). Geneticist and evolutionary biologist J.B.S. Haldane criticized Lewis for his scientifically inaccurate descriptions of the planets, and his disdain for the scientific establishment. Lewis responded to the criticism in essays of his own. Another of Lewis's favorite scientific targets was atheist Fred Hoyle, whom he openly criticized for anti-Christian statements in Hoyle's BBC radio series. Writer and Lewis friend Dorothy L. Sayers voiced her own criticism of Hoyle. In a letter, Lewis dismissed Hoyle as "not a great philosopher (and none of my scientific colleagues think much of him as a scientist.” Given Lewis's lack of respect for Hoyle, and use of creative license in describing the planets, and the flat-earth, "geocentric” Narnia, it is surprising that Lewis very carefully includes an astronomically correct description of red giants in two novels in the Narnia series ("The Magician's Nephew" and "The Last Battle"). This inclusion is even more curious given that Fred Hoyle is well-known as one of the pioneers in the field of stellar death and the properties of red giants.

  13. GRANULATION SIGNATURES IN THE SPECTRUM OF THE VERY METAL-POOR RED GIANT HD 122563

    International Nuclear Information System (INIS)

    RamIrez, I.; Collet, R.; Asplund, M.; Lambert, D. L.; Allende Prieto, C.

    2010-01-01

    A very high resolution (R = λ/Δλ = 200, 000), high signal-to-noise ratio (S/N ≅ 340) blue-green spectrum of the very metal-poor ([Fe/H] ≅ -2.6) red giant star HD 122563 has been obtained by us at McDonald Observatory. We measure the asymmetries and core wavelengths of a set of unblended Fe I lines covering a wide range of line strength. Line bisectors exhibit the characteristic C-shape signature of surface convection (granulation) and they span from about 100 m s -1 in the strongest Fe I features to 800 m s -1 in the weakest ones. Core wavelength shifts range from about -100 to -900 m s -1 , depending on line strength. In general, larger blueshifts are observed in weaker lines, but there is increasing scatter with increasing residual flux. Assuming local thermodynamic equilibrium (LTE), we synthesize the same set of spectral lines using a state-of-the-art three-dimensional (3D) hydrodynamic simulation for a stellar atmosphere of fundamental parameters similar to those of HD 122563. We find good agreement between model predictions and observations. This allows us to infer an absolute zero point for the line shifts and radial velocity. Moreover, it indicates that the structure and dynamics of the simulation are realistic, thus providing support to previous claims of large 3D-LTE corrections to elemental abundances and fundamental parameters of very metal-poor red giant stars obtained with standard 1D-LTE spectroscopic analyses, as suggested by the hydrodynamic model used here.

  14. The magnetic fields at the surface of active single G-K giants

    Science.gov (United States)

    Aurière, M.; Konstantinova-Antova, R.; Charbonnel, C.; Wade, G. A.; Tsvetkova, S.; Petit, P.; Dintrans, B.; Drake, N. A.; Decressin, T.; Lagarde, N.; Donati, J.-F.; Roudier, T.; Lignières, F.; Schröder, K.-P.; Landstreet, J. D.; Lèbre, A.; Weiss, W. W.; Zahn, J.-P.

    2015-02-01

    Aims: We investigate the magnetic field at the surface of 48 red giants selected as promising for detection of Stokes V Zeeman signatures in their spectral lines. In our sample, 24 stars are identified from the literature as presenting moderate to strong signs of magnetic activity. An additional 7 stars are identified as those in which thermohaline mixing appears not to have occured, which could be due to hosting a strong magnetic field. Finally, we observed 17 additional very bright stars which enable a sensitive search to be performed with the spectropolarimetric technique. Methods: We use the spectropolarimeters Narval and ESPaDOnS to detect circular polarization within the photospheric absorption lines of our targets. We treat the spectropolarimetric data using the least-squares deconvolution method to create high signal-to-noise ratio mean Stokes V profiles. We also measure the classical S-index activity indicator for the Ca ii H&K lines, and the stellar radial velocity. To infer the evolutionary status of our giants and to interpret our results, we use state-of-the-art stellar evolutionary models with predictions of convective turnover times. Results: We unambiguously detect magnetic fields via Zeeman signatures in 29 of the 48 red giants in our sample. Zeeman signatures are found in all but one of the 24 red giants exhibiting signs of activity, as well as 6 out of 17 bright giant stars. However no detections were obtained in the 7 thermohaline deviant giants. The majority of the magnetically detected giants are either in the first dredge up phase or at the beginning of core He burning, i.e. phases when the convective turnover time is at a maximum: this corresponds to a "magnetic strip" for red giants in the Hertzsprung-Russell diagram. A close study of the 16 giants with known rotational periods shows that the measured magnetic field strength is tightly correlated with the rotational properties, namely to the rotational period and to the Rossby number Ro

  15. Testing Scaling Relations for Solar-like Oscillations from the Main Sequence to Red Giants Using Kepler Data

    DEFF Research Database (Denmark)

    Huber, D.; Bedding, T.R.; Stello, D.

    2011-01-01

    ), and oscillation amplitudes. We show that the difference of the Δν-νmax relation for unevolved and evolved stars can be explained by different distributions in effective temperature and stellar mass, in agreement with what is expected from scaling relations. For oscillation amplitudes, we show that neither (L/M) s......We have analyzed solar-like oscillations in ~1700 stars observed by the Kepler Mission, spanning from the main sequence to the red clump. Using evolutionary models, we test asteroseismic scaling relations for the frequency of maximum power (νmax), the large frequency separation (Δν...... scaling nor the revised scaling relation by Kjeldsen & Bedding is accurate for red-giant stars, and demonstrate that a revised scaling relation with a separate luminosity-mass dependence can be used to calculate amplitudes from the main sequence to red giants to a precision of ~25%. The residuals show...

  16. Oscillating Red Giants Observed during Campaign 1 of the Kepler K2 Mission: New Prospects for Galactic Archaeology

    Science.gov (United States)

    Stello, Dennis; Huber, Daniel; Sharma, Sanjib; Johnson, Jennifer; Lund, Mikkel N.; Handberg, Rasmus; Buzasi, Derek L.; Silva Aguirre, Victor; Chaplin, William J.; Miglio, Andrea; Pinsonneault, Marc; Basu, Sarbani; Bedding, Tim R.; Bland-Hawthorn, Joss; Casagrande, Luca; Davies, Guy; Elsworth, Yvonne; Garcia, Rafael A.; Mathur, Savita; Di Mauro, Maria Pia; Mosser, Benoit; Schneider, Donald P.; Serenelli, Aldo; Valentini, Marica

    2015-08-01

    NASA’s re-purposed Kepler mission—dubbed K2—has brought new scientific opportunities that were not anticipated for the original Kepler mission. One science goal that makes optimal use of K2's capabilities, in particular its 360° ecliptic field of view, is galactic archaeology—the study of the evolution of the Galaxy from the fossil stellar record. The thrust of this research is to exploit high-precision, time-resolved photometry from K2 in order to detect oscillations in red giant stars. This asteroseismic information can provide estimates of stellar radius (hence distance), mass, and age of vast numbers of stars across the Galaxy. Here we present the initial analysis of a subset of red giants, observed toward the north galactic gap, during the mission’s first full science campaign. We investigate the feasibility of using K2 data for detecting oscillations in red giants that span a range in apparent magnitude and evolutionary state (hence intrinsic luminosity). We demonstrate that oscillations are detectable for essentially all cool giants within the {log}g range ˜1.9-3.2. Our detection is complete down to {\\text{Kp}} ˜ 14.5, which results in a seismic sample with little or no detection bias. This sample is ideally suited to stellar population studies that seek to investigate potential shortcomings of contemporary Galaxy models.

  17. STRUCTURAL GLITCHES NEAR THE CORES OF RED GIANTS REVEALED BY OSCILLATIONS IN G-MODE PERIOD SPACINGS FROM STELLAR MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, M. S.; Avelino, P. P. [Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto (Portugal); Stello, D. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Christensen-Dalsgaard, J. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Townsend, R. H. D., E-mail: mcunha@astro.up.pt [Department of Astronomy, University of Wisconsin–Madison, 2535 Sterling Hall, 475 N. Charter Street, Madison, WI 53706 (United States)

    2015-06-01

    With recent advances in asteroseismology it is now possible to peer into the cores of red giants, potentially providing a way to study processes such as nuclear burning and mixing through their imprint as sharp structural variations—glitches—in the stellar cores. Here we show how such core glitches can affect the oscillations we observe in red giants. We derive an analytical expression describing the expected frequency pattern in the presence of a glitch. This formulation also accounts for the coupling between acoustic and gravity waves. From an extensive set of canonical stellar models we find glitch-induced variation in the period spacing and inertia of non-radial modes during several phases of red giant evolution. Significant changes are seen in the appearance of mode amplitude and frequency patterns in asteroseismic diagrams such as the power spectrum and the échelle diagram. Interestingly, along the red giant branch glitch-induced variation occurs only at the luminosity bump, potentially providing a direct seismic indicator of stars in that particular evolution stage. Similarly, we find the variation at only certain post-helium-ignition evolution stages, namely, in the early phases of helium core burning and at the beginning of helium shell burning, signifying the asymptotic giant branch bump. Based on our results, we note that assuming stars to be glitch-free, while they are not, can result in an incorrect estimate of the period spacing. We further note that including diffusion and mixing beyond classical Schwarzschild could affect the characteristics of the glitches, potentially providing a way to study these physical processes.

  18. Antisolar differential rotation with surface lithium enrichment on the single K-giant V1192 Orionis

    Science.gov (United States)

    Kővári, Zs.; Strassmeier, K. G.; Carroll, T. A.; Oláh, K.; Kriskovics, L.; Kővári, E.; Kovács, O.; Vida, K.; Granzer, T.; Weber, M.

    2017-10-01

    Context. Stars with about 1-2 solar masses at the red giant branch (RGB) represent an intriguing period of stellar evolution, I.e. when the convective envelope interacts with the fast-rotating core. During these mixing episodes freshly synthesized lithium can come up to the stellar surface along with high angular momentum material. This high angular momentum may alter the surface rotation pattern. Aims: The single rapidly rotating K-giant V1192 Ori is revisited to determine its surface differential rotation, lithium abundance, and basic stellar properties such as a precise rotation period. The aim is to independently verify the antisolar differential rotation of the star and possibly find a connection to the surface lithium abundance. Methods: We applied time-series Doppler imaging to a new multi-epoch data set. Altogether we reconstructed 11 Doppler images from spectroscopic data collected with the STELLA robotic telescope between 2007-2016. We used our inversion code iMap to reconstruct all stellar surface maps. We extracted the differential rotation from these images by tracing systematic spot migration as a function of stellar latitude from consecutive image cross-correlations. Results: The position of V1192 Ori in the Hertzsprung-Russell diagram suggests that the star is in the helium core-burning phase just leaving the RGB bump. We measure A(Li)NLTE = 1.27, I.e. a value close to the anticipated transition value of 1.5 from Li-normal to Li-rich giants. Doppler images reveal extended dark areas arranged quasi-evenly along an equatorial belt. No cool polar spot is found during the investigated epoch. Spot displacements clearly suggest antisolar surface differential rotation with α = - 0.11 ± 0.02 shear coefficient. Conclusions: The surface Li enrichment and the peculiar surface rotation pattern may indicate a common origin. Based on data obtained with the STELLA robotic observatory in Tenerife, an AIP facility jointly operated by AIP and IAC.

  19. Single-cell measurement of red blood cell oxygen affinity

    OpenAIRE

    Caprio, Di; Stokes, Chris; Higgins, John M.; Schonbrun, Ethan

    2015-01-01

    Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system....

  20. CHEMICAL ABUNDANCE ANALYSIS OF A NEUTRON-CAPTURE ENHANCED RED GIANT IN THE BULGE PLAUT FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Christian I.; Rich, R. Michael [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); McWilliam, Andrew, E-mail: cijohnson@astro.ucla.edu, E-mail: rmr@astro.ucla.edu, E-mail: cjohnson@cfa.harvard.edu, E-mail: andy@obs.carnegiescience.edu [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States)

    2013-09-20

    We present chemical abundances for 27 elements ranging from oxygen to erbium in the metal-poor ([Fe/H] = –1.67) bulge red giant branch star 2MASS 18174532-3353235. The results are based on equivalent width and spectrum synthesis analyses of a high-resolution (R ∼ 30, 000) spectrum obtained with the Magellan-MIKE spectrograph. While the light (Z ∼< 30) element abundance patterns match those of similar metallicity bulge and halo stars, the strongly enhanced heavy element abundances are more similar to 'r-II' halo stars (e.g., CS 22892-052) typically found at [Fe/H] ∼< – 2.5. We find that the heaviest elements (Z ≥ 56) closely follow the scaled-solar r-process abundance pattern. We do not find evidence supporting significant s-process contributions; however, the intermediate mass elements (e.g., Y and Zr) appear to have been produced through a different process than the heaviest elements. The light and heavy element abundance patterns of 2MASS 18174532-3353235 are in good agreement with the more metal-poor r-process enhanced stars CS 22892-052 and BD +17{sup o}3248. 2MASS 18174532-3353235 also shares many chemical characteristics with the similar metallicity but comparatively α-poor Ursa Minor dwarf galaxy giant COS 82. Interestingly, the Mo and Ru abundances of 2MASS 18174532-3353235 are also strongly enhanced and follow a similar trend recently found to be common in moderately metal-poor main-sequence turn-off halo stars.

  1. FUNDAMENTAL PARAMETERS, INTEGRATED RED GIANT BRANCH MASS LOSS, AND DUST PRODUCTION IN THE GALACTIC GLOBULAR CLUSTER 47 TUCANAE

    International Nuclear Information System (INIS)

    McDonald, I.; Zijlstra, A. A.; Boyer, M. L.; Gordon, K.; Meixner, M.; Sewilo, M.; Shiao, B.; Whitney, B.; Van Loon, J. Th.; Hora, J. L.; Robitaille, T.; Babler, B.; Meade, M.; Block, M.; Misselt, K.

    2011-01-01

    Fundamental parameters and time evolution of mass loss are investigated for post-main-sequence stars in the Galactic globular cluster 47 Tucanae (NGC 104). This is accomplished by fitting spectral energy distributions (SEDs) to existing optical and infrared photometry and spectroscopy, to produce a true Hertzsprung-Russell diagram. We confirm the cluster's distance as d = 4611 +213 -200 pc and age as 12 ± 1 Gyr. Horizontal branch models appear to confirm that no more red giant branch mass loss occurs in 47 Tuc than in the more metal-poor ω Centauri, though difficulties arise due to inconsistencies between the models. Using our SEDs, we identify those stars that exhibit infrared excess, finding excess only among the brightest giants: dusty mass loss begins at a luminosity of ∼1000 L sun , becoming ubiquitous above L = 2000 L sun . Recent claims of dust production around lower-luminosity giants cannot be reproduced, despite using the same archival Spitzer imagery.

  2. Seismic constraints on the radial dependence of the internal rotation profiles of six Kepler subgiants and young red giants

    Science.gov (United States)

    Deheuvels, S.; Doğan, G.; Goupil, M. J.; Appourchaux, T.; Benomar, O.; Bruntt, H.; Campante, T. L.; Casagrande, L.; Ceillier, T.; Davies, G. R.; De Cat, P.; Fu, J. N.; García, R. A.; Lobel, A.; Mosser, B.; Reese, D. R.; Regulo, C.; Schou, J.; Stahn, T.; Thygesen, A. O.; Yang, X. H.; Chaplin, W. J.; Christensen-Dalsgaard, J.; Eggenberger, P.; Gizon, L.; Mathis, S.; Molenda-Żakowicz, J.; Pinsonneault, M.

    2014-04-01

    Context. We still do not understand which physical mechanisms are responsible for the transport of angular momentum inside stars. The recent detection of mixed modes that contain the clear signature of rotation in the spectra of Kepler subgiants and red giants gives us the opportunity to make progress on this question. Aims: Our aim is to probe the radial dependence of the rotation profiles for a sample of Kepler targets. For this purpose, subgiants and early red giants are particularly interesting targets because their rotational splittings are more sensitive to the rotation outside the deeper core than is the case for their more evolved counterparts. Methods: We first extracted the rotational splittings and frequencies of the modes for six young Kepler red giants. We then performed a seismic modeling of these stars using the evolutionary codes Cesam2k and astec. By using the observed splittings and the rotational kernels of the optimal models, we inverted the internal rotation profiles of the six stars. Results: We obtain estimates of the core rotation rates for these stars, and upper limits to the rotation in their convective envelope. We show that the rotation contrast between the core and the envelope increases during the subgiant branch. Our results also suggest that the core of subgiants spins up with time, while their envelope spins down. For two of the stars, we show that a discontinuous rotation profile with a deep discontinuity reproduces the observed splittings significantly better than a smooth rotation profile. Interestingly, the depths that are found to be most probable for the discontinuities roughly coincide with the location of the H-burning shell, which separates the layers that contract from those that expand. Conclusions: We characterized the differential rotation pattern of six young giants with a range of metallicities, and with both radiative and convective cores on the main sequence. This will bring observational constraints to the

  3. The Near-infrared Tip of the Red Giant Branch. II. An Absolute Calibration in the Large Magellanic Cloud

    Science.gov (United States)

    Hoyt, Taylor J.; Freedman, Wendy L.; Madore, Barry F.; Seibert, Mark; Beaton, Rachael L.; Hatt, Dylan; Jang, In Sung; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.

    2018-05-01

    We present a new empirical JHK absolute calibration of the tip of the red giant branch (TRGB) in the Large Magellanic Cloud (LMC). We use published data from the extensive Near-Infrared Synoptic Survey containing 3.5 million stars, 65,000 of which are red giants that fall within one magnitude of the TRGB. Adopting the TRGB slopes from a companion study of the isolated dwarf galaxy IC 1613, as well as an LMC distance modulus of μ 0 = 18.49 mag from (geometric) detached eclipsing binaries, we derive absolute JHK zero points for the near-infrared TRGB. For a comparison with measurements in the bar alone, we apply the calibrated JHK TRGB to a 500 deg2 area of the 2MASS survey. The TRGB reveals the 3D structure of the LMC with a tilt in the direction perpendicular to the major axis of the bar, which is in agreement with previous studies.

  4. Deep learning classification in asteroseismology using an improved neural network: results on 15 000 Kepler red giants and applications to K2 and TESS data

    Science.gov (United States)

    Hon, Marc; Stello, Dennis; Yu, Jie

    2018-05-01

    Deep learning in the form of 1D convolutional neural networks have previously been shown to be capable of efficiently classifying the evolutionary state of oscillating red giants into red giant branch stars and helium-core burning stars by recognizing visual features in their asteroseismic frequency spectra. We elaborate further on the deep learning method by developing an improved convolutional neural network classifier. To make our method useful for current and future space missions such as K2, TESS, and PLATO, we train classifiers that are able to classify the evolutionary states of lower frequency resolution spectra expected from these missions. Additionally, we provide new classifications for 8633 Kepler red giants, out of which 426 have previously not been classified using asteroseismology. This brings the total to 14983 Kepler red giants classified with our new neural network. We also verify that our classifiers are remarkably robust to suboptimal data, including low signal-to-noise and incorrect training truth labels.

  5. Infrared tip of the red giant branch and distances to the MAFFEI/IC 342 group

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Po-Feng; Tully, R. Brent; Jacobs, Bradley A. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, HI 96822 (United States); Rizzi, Luca [W. M. Keck Observatory, 65-1120 Mamalahoa Hwy, Kamuela, HI 96743 (United States); Dolphin, Andrew E. [Raytheon, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Karachentsev, Igor D. [Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnij Arkhyz, Karachai-Cherkessian Republic 369167 (Russian Federation)

    2014-07-01

    In this paper, we extend the use of the tip of the red giant branch (TRGB) method to near-infrared wavelengths from the previously used I-band, using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3). Upon calibration of a color dependency of the TRGB magnitude, the IR TRGB yields a random uncertainty of ∼5% in relative distance. The IR TRGB methodology has an advantage over the previously used Advance Camera for Surveys F606W and F814W filter set for galaxies that suffer from severe extinction. Using the IR TRGB methodology, we obtain distances toward three principal galaxies in the Maffei/IC 342 complex, which are located at low Galactic latitudes. New distance estimates using the TRGB method are 3.45{sub −0.13}{sup +0.13} Mpc for IC 342, 3.37{sub −0.23}{sup +0.32} Mpc for Maffei 1, and 3.52{sub −0.30}{sup +0.32} Mpc for Maffei 2. The uncertainties are dominated by uncertain extinction, especially for Maffei 1 and Maffei 2. Our IR calibration demonstrates the viability of the TRGB methodology for observations with the James Webb Space Telescope.

  6. POPULATION EFFECTS ON THE METALLICITY DISTRIBUTION FUNCTION DERIVED FROM THE RED GIANT BRANCH

    International Nuclear Information System (INIS)

    Ordoñez, Antonio J.; Sarajedini, Ata

    2015-01-01

    We have tested the reliability of the red giant branch (RGB) as a metallicity indicator accounting for observational errors as well as the complexity of star formation histories and chemical evolution histories observed in various stellar systems. We generate model color–magnitude diagrams (CMDs) produced with a variety of evolutionary histories and compare the resultant metallicity estimates from the colors and magnitudes of RGB stars to the true input metallicities. We include realistic models for photometric errors and completeness in our synthetic CMDs. As expected, for simple simple stellar populations dominated by old stars, the RGB provides a very accurate estimate of the modular metallicity value for a population. An error in the age of a system targeted for this type of study may produce metallicity errors of a few tenths of a dex. The size of this metallicity error depends linearly on the age error, and we find this dependence to be stronger with more precise photometry. If the population has experienced any significant star formation within the last ∼6 Gyr, the metallicity estimates, [M/H], derived from the RGB may be in error by up to ∼0.5 dex. Perhaps the most important consideration for this technique is an accurate, independent estimate of the average age for the target stellar system, especially if it is probable that a significant fraction of the population formed less than ∼6 Gyr ago

  7. Amino acid composition and functional properties of giant red sea cucumber ( Parastichopus californicus) collagen hydrolysates

    Science.gov (United States)

    Liu, Zunying; Su, Yicheng; Zeng, Mingyong

    2011-03-01

    Giant red sea cucumber ( Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis. The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species. The degree of hydrolysis (DH), amino acid composition, SDS-PAGE, emulsion activity index (EAI), emulsion stability index (ESI), foam expansion (FE), and foam stability (FS) of hydrolysates were investigated. The effects of pH on the EAI, ESI FE and FS of hydrolysates were also investigated. The results indicated that the β and α 1 chains of the collagen were effectively hydrolyzed by trypsin at 50°c with an Enzyme/Substrate (E/S) ration of 1:20 (w:w). The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin. The hydrolysates had a molecular weight distribution of 1.1-17 kDa, and were abundant in glycine (Gly), proline (Pro), glutamic acid (Glu), alanine (Ala) and hydroxyproline (Hyp) residues. The hydrolysates were fractionated into three fractions ( 10 kDa), and the fraction of 3-10 kDa exhibited a higher EAI value than the fraction of > 10 kDa ( P 10 kDa had higher FE and FS values than other fractions ( P 10 kDa showed higher FE value, respectively. They are hoped to be utilized as functional ingredients in food and nutraceutical industries.

  8. Chemical Abundances of Red Giant Branch Stars in the Globular Cluster NGC 288

    Science.gov (United States)

    Hsyu, Tiffany; Johnson, C. I.; Pilachowski, C. A.; Lee, Y.; Rich, R. M.

    2013-01-01

    We present chemical abundances and radial velocities for ~30 red giant branch (RGB) stars in the globular cluster NGC 288. The results are based on moderate resolution (R≈18,000) and moderate signal-to-noise ratio 50-75) obtained with the Hydra multi-object spectrograph on the Blanco 4m telescope. NGC 288 has been shown to exhibit two separate RGBs and we investigate possible differences in metallicity and/or light element abundances between stars on each branch. We present a new filter tracing for the CTIO Calcium HK narrow band filter and explore its effects on previous globular cluster color-magnitude diagrams. We also compare the light element abundance patterns of NGC 288 to those of other similar metallicity halo clusters. This material is based upon work supported by the National Science Foundation under award No.AST-1003201 to C.I.J. C.A.P. gratefully acknowledges support from the Daniel Kirkwood Research Fund at Indiana University. R.M.R. acknowledges support from NSF grants AST-0709479 and AST-121120995.

  9. Chemical Abundances of Red Giant Branch Stars in the Globular Clusters NGC 6333 and NGC 6366

    Science.gov (United States)

    Johnson, Christian I.; Rich, R. M.; Pilachowski, C. A.; Kunder, A. M.

    2013-01-01

    We present chemical abundances and radial velocities for >20 red giant branch (RGB) stars in the Galactic globular clusters NGC 6333 ([Fe/H]≈-1.8) and NGC 6366 ([Fe/H]≈-0.6). The results are based on moderate resolution (R=18,000), high signal-to-noise ratio (>100) spectra obtained with the Hydra multifiber positioner and bench spectrograph on the WIYN 3.5m telescope at Kitt Peak National Observatory. Both objects are likely associated with the Galactic bulge globular cluster system, and we therefore compare the cluster abundance patterns with those of nearby bulge field stars. Additionally, we investigate differences in the O-Na anticorrelation and neutron-capture element dispersion between the two clusters, and compare their abundance patterns with those of similar metallicity halo globular clusters. This material is based upon work supported by the National Science Foundation under award No. AST-1003201 to C.I.J. C.A.P. gratefully acknowledges support from the Daniel Kirkwood Research Fund at Indiana University. R.M.R. acknowledges support from NSF grant AST-0709479 and AST-121120995.

  10. VizieR Online Data Catalog: JHK lightcurves of red giants in the SMC (Takayama+, 2015)

    Science.gov (United States)

    Takayama, M.; Wood, P. R.; Ita, Y.

    2017-11-01

    This is JHK light curves of 7 oxygen rich stars and 14 carbon stars which show the variability of prominent long secondary periods (LSPs). Those stars are cross-identified with OGLE LSP variables in the Small Magellanic Cloud (Soszynski et al. 2011, J/AcA/61/217). A long-term multiband near-IR photometric survey for variable stars in the Large and Small Magellanic Clouds has been carried out at the South African Astronomical Observatory at Sutherland (Ita et al., in preparation). The SIRIUS camera attached to the IRSF 1.4 m telescope was used for this survey and more than 10 yr of observations in the near-IR bands J(1.25 μm), H(1.63 μm) and KS(2.14 μm) band were obtained. In this work, we select the SMC stars from the SIRIUS data base. We obtained the V- and I-band time series of SMC red giants from the OGLE project (Soszynski et al. 2011, J/AcA/61/217). (2 data files).

  11. 99 mTc-sulphur-colloid and heat-denatured 99mTc-labelled red cell scans demonstrating a giant intrapelvic spleen in a girl after splenectomy

    International Nuclear Information System (INIS)

    Kao, P.F.; Tzen, K.Y.; Tsai, M.F.; Lin, J.N.

    2001-01-01

    A 17 x 12 x 5-cm giant intrapelvic mass in a 14-year-old girl is reported. This mass developed 6 years after a splenectomy for splenic torsion. The heat-denatured 99 m Tc-labelled red cell scan and 99 m Tc- sulphur-colloid scan confirmed the specific red cell sequestration function and reticuloendothelial activity in the giant intrapelvic spleen. The size and development of the giant intrapelvic spleen are unusual. The usefulness of functional images to diagnosis the nature of the intrapelvic mass is well demonstrated. (orig.)

  12. The chemical composition of red giants in 47 Tucanae. II. Magnesium isotopes and pollution scenarios

    Science.gov (United States)

    Thygesen, A. O.; Sbordone, L.; Ludwig, H.-G.; Ventura, P.; Yong, D.; Collet, R.; Christlieb, N.; Melendez, J.; Zaggia, S.

    2016-04-01

    Context. The phenomenon of multiple populations in globular clusters is still far from understood, with several proposed mechanisms to explain the observed behaviour. The study of elemental and isotopic abundance patterns are crucial for investigating the differences among candidate pollution mechanisms. Aims: We derive magnesium isotopic ratios for 13 stars in the globular cluster 47 Tucanae (NGC 104) to provide new, detailed information about the nucleosynthesis that has occurred within the cluster. For the first time, the impact of 3D model stellar atmospheres on the derived Mg isotopic ratios is investigated. Methods: Using both tailored 1D atmospheric models and 3D hydrodynamical models, we derive magnesium isotopic ratios from four features of MgH near 5135 Å in 13 giants near the tip of the red giant branch, using high signal-to-noise, high-resolution spectra. Results: We derive the magnesium isotopic ratios for all stars and find no significant offset of the isotopic distribution between the pristine and the polluted populations. Furthermore, we do not detect any statistically significant differences in the spread in the Mg isotopes in either population. No trends were found between the Mg isotopes and [Al/Fe]. The inclusion of 3D atmospheres has a significant impact on the derived 25Mg/24Mg ratio, increasing it by a factor of up to 2.5, compared to 1D. The 26Mg/24Mg ratio, on the other hand, essentially remains unchanged. Conclusions: We confirm the results seen from other globular clusters, where no strong variation in the isotopic ratios is observed between stellar populations, for observed ranges in [Al/Fe]. We see no evidence for any significant activation of the Mg-Al burning chain. The use of 3D atmospheres causes an increase of a factor of up to 2.5 in the fraction of 25Mg, resolving part of the discrepancy between the observed isotopic fraction and the predictions from pollution models. Based on observations made with the ESO Very Large Telescope

  13. First detection of rotational CO line emission in a red giant branch star

    Science.gov (United States)

    Groenewegen, M. A. T.

    2014-01-01

    Context. For stars with initial masses below ~1 M⊙, the mass loss during the first red giant branch (RGB) phase dominates mass loss in the later asymptotic giant branch (AGB) phase. Nevertheless, mass loss on the RGB is still often parameterised by a simple Reimers law in stellar evolution models. Aims: To try to detect CO thermal emission in a small sample of nearby RGB stars with reliable Hipparcos parallaxes that were shown to have infrared excess in an earlier paper. Methods: A sample of five stars was observed in the CO J = 2-1 and J = 3-2 lines with the IRAM and APEX telescopes. Results: One star, the one with the largest mass-loss rate based on the previous analysis of the spectral energy distribution, was detected. The expansion velocity is unexpectedly large at 12 km s-1. The line profile and intensity are compared to the predictions from a molecular line emission code. The standard model predicts a double-peaked profile, while the observations indicate a flatter profile. A model that does fit the data has a much smaller CO envelope (by a factor of 3), and a CO abundance that is two times larger and/or a larger mass-loss rate than the standard model. This could indicate that the phase of large mass loss has only recently started. Conclusions: The detection of CO in an RGB star with a luminosity of only ~1300 L⊙ and a mass-loss rate as low as a few 10-9M⊙ yr-1 is important and the results also raise new questions. However, ALMA observations are required in order to study the mass-loss process of RGB stars in more detail, both for reasons of sensitivity (6 h of integration in superior weather at IRAM were needed to get a 4σ detection in the object with the largest detection probability), and spatial resolution (to determine the size of the CO envelope). Based on observations made with ESO telescopes at the La Silla Paranal Observatory under programme ID 091.D-0073 (ESO time) and 091.F-9322 (Swedish time). Based on observations with the Atacama

  14. Giant current fluctuations in an overheated single-electron transistor

    NARCIS (Netherlands)

    Laakso, M.A.; Heikkilä, T.T.; Nazarov, Y.V.

    2010-01-01

    Interplay of cotunneling and single-electron tunneling in a thermally isolated single-electron transistor leads to peculiar overheating effects. In particular, there is an interesting crossover interval where the competition between cotunneling and single-electron tunneling changes to the dominance

  15. Carbon Flux Through the Giant Barrel Sponge Xestospongia testudinaria in the Red Sea

    KAUST Repository

    Wooster, Michael K.

    2017-11-01

    Sponges have important ecological functions on coral reefs because they are regionally abundant, competitively dominant, and process large volumes of seawater. The sponge loop hypothesis proposes that sponges consume dissolved organic carbon (DOC) and then releases the carbon as shed cellular detritus back to the reef benthos. Within this context, we examined the carbon flux mediated by the giant barrel sponge, Xestospongia testudinaria, on reefs in the Red Sea, where sponge abundance is comparatively low relative to coral reefs elsewhere, such as the Caribbean. Seawater samples were collected from the incurrent and excurrent (In-Ex) flow of 40 sponges from inshore, mid-shelf, and offshore reefs between 18° and 22°N latitude off the coast of Saudi Arabia. Concentrations of DOC and living particulate organic carbon (LPOC) were significantly higher in incurrent (ambient) seawater on inshore reefs than mid-shelf and offshore reefs. Consistent with studies of X. muta in the Caribbean, the diet of X. testudinaria is comprised primarily of DOC; mean values of the nutritional components across all sites were 60.5% DOC, 35.7% detritus, and 3.8% LPOC. Taking into account the specific filtration rates of nutritional components and oxygen consumption of sponges across the inshore-offshore gradient, there is evidence (1) of a threshold concentration of DOC below which sponges cease to be net consumers of DOC, and (2) that sponges on offshore reefs are food-limited. Contrary to the sponge loop hypothesis, there was no evidence that X. testudinaria, returned DOC to the benthos in the form of detritus, but was, instead, a net consumer of detritus from the water column. Unlike the cryptic, interstitial sponges that were studied to advance the sponge-loop hypothesis, emergent sponges may have an alternate pathway for returning DOC to the benthos by converting it to sponge biomass rather than sponge detritus.

  16. Age-resolved chemistry of red giants in the solar neighbourhood

    Science.gov (United States)

    Feuillet, Diane K.; Bovy, Jo; Holtzman, Jon; Weinberg, David H.; García-Hernández, D.; Hearty, Fred R.; Majewski, Steven R.; Roman-Lopes, Alexandre; Rybizki, Jan; Zamora, Olga

    2018-06-01

    In the age of high-resolution spectroscopic stellar surveys of the Milky Way, the number of stars with detailed abundances of multiple elements is rapidly increasing. These elemental abundances are directly influenced by the evolutionary history of the Galaxy, but this can be difficult to interpret without an absolute timeline of the abundance enrichment. We present age-abundance trends for [M/H], [α/M], and 17 individual elements using a sample of 721 solar neighbourhood Hipparcos red giant stars observed by Apache Point Observatory Galactic Evolution Experiment. These age trends are determined through a Bayesian hierarchical modelling method presented by Feuillet et al. We confirm that the [α/M]-age relation in the solar neighbourhood is steep and relatively narrow (0.20 dex age dispersion), as are the [O/M]-age and [Mg/M]-age relations. The age trend of [C/N] is steep and smooth, consistent with stellar evolution. The [M/H]-age relation has a mean age dispersion of 0.28 dex and a complex overall structure. The oldest stars in our sample are those with the lowest and highest metallicities, while the youngest stars are those with solar metallicity. These results provide strong constraints on theoretical models of Galactic chemical evolution (GCE). We compare them to the predictions of one-zone GCE models and multizone mixtures, both analytic and numerical. These comparisons support the hypothesis that the solar neighbourhood is composed of stars born at a range of Galactocentric radii, and that the most metal-rich stars likely migrated from a region with earlier and more rapid star formation such as the inner Galaxy.

  17. TESTING THE ASTEROSEISMIC SCALING RELATIONS FOR RED GIANTS WITH ECLIPSING BINARIES OBSERVED BY KEPLER

    Energy Technology Data Exchange (ETDEWEB)

    Gaulme, P.; McKeever, J.; Jackiewicz, J.; Rawls, M. L. [Department of Astronomy, New Mexico State University, P.O. Box 30001, MSC 4500, Las Cruces, NM 88003-8001 (United States); Corsaro, E. [Laboratoire AIM, CEA/DRF-CNRS, Université Paris 7 Diderot, IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Mosser, B. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Université Pierre et Marie Curie, Université Denis Diderot, F-92195 Meudon (France); Southworth, J. [Astrophysics Group, Keele University, Staffordshire, ST5 5BG (United Kingdom); Mahadevan, S.; Bender, C.; Deshpande, R., E-mail: gaulme@nmsu.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)

    2016-12-01

    Given the potential of ensemble asteroseismology for understanding fundamental properties of large numbers of stars, it is critical to determine the accuracy of the scaling relations on which these measurements are based. From several powerful validation techniques, all indications so far show that stellar radius estimates from the asteroseismic scaling relations are accurate to within a few percent. Eclipsing binary systems hosting at least one star with detectable solar-like oscillations constitute the ideal test objects for validating asteroseismic radius and mass inferences. By combining radial velocity (RV) measurements and photometric time series of eclipses, it is possible to determine the masses and radii of each component of a double-lined spectroscopic binary. We report the results of a four-year RV survey performed with the échelle spectrometer of the Astrophysical Research Consortium’s 3.5 m telescope and the APOGEE spectrometer at Apache Point Observatory. We compare the masses and radii of 10 red giants (RGs) obtained by combining radial velocities and eclipse photometry with the estimates from the asteroseismic scaling relations. We find that the asteroseismic scaling relations overestimate RG radii by about 5% on average and masses by about 15% for stars at various stages of RG evolution. Systematic overestimation of mass leads to underestimation of stellar age, which can have important implications for ensemble asteroseismology used for Galactic studies. As part of a second objective, where asteroseismology is used for understanding binary systems, we confirm that oscillations of RGs in close binaries can be suppressed enough to be undetectable, a hypothesis that was proposed in a previous work.

  18. Chemical Abundances of Red Giant Stars in the Globular Cluster M107 (NGC 6171)

    Science.gov (United States)

    O'Connell, Julia E.; Johnson, Christian I.; Pilachowski, Catherine A.; Burks, Geoffrey

    2011-10-01

    We present chemical abundances of Al and several Fe-Peak and neutron-capture elements for 13 red giant branch stars in the Galactic globular cluster NGC 6171 (M107). The abundances were determined using equivalent width and spectrum synthesis analyses of moderate-resolution ( R ˜ 15,000), moderate signal-to-noise ratio ( ˜ 80) spectra obtained with the WIYN telescope and Hydra multifiber spectrograph. A comparison between photometric and spectroscopic effective temperature estimates seems to indicate that a reddening value of E(B - V) = 0.46 may be more appropriate for this cluster than the more commonly used value of E(B - V) = 0.33. Similarly, we found that a distance modulus of (m - M)V ≈ 13.7 provided reasonable surface gravity estimates for the stars in our sample. Our spectroscopic analysis finds M107 to be moderately metal-poor with = -0.93 and also exhibits a small star-to-star metallicity dispersion (σ = 0.04). These results are consistent with previous photometric and spectroscopic studies. Aluminum appears to be moderately enhanced in all program stars ( = +0.39, σ = 0.11). The relatively small star-to-star scatter in [Al/Fe] differs from the trend found in more metal-poor globular clusters, and is more similar to what is found in clusters with [Fe/H] ≳ -1. The cluster also appears to be moderately r-process-enriched with = +0.32 (σ = 0.17).

  19. Atmospheric parameters and chemical properties of red giants in the CoRoT asteroseismology fields

    Science.gov (United States)

    Morel, T.; Miglio, A.; Lagarde, N.; Montalbán, J.; Rainer, M.; Poretti, E.; Eggenberger, P.; Hekker, S.; Kallinger, T.; Mosser, B.; Valentini, M.; Carrier, F.; Hareter, M.; Mantegazza, L.

    2014-04-01

    A precise characterisation of the red giants in the seismology fields of the CoRoT satellite is a prerequisite for further in-depth seismic modelling. High-resolution FEROS and HARPS spectra were obtained as part of the ground-based follow-up campaigns for 19 targets holding great asteroseismic potential. These data are used to accurately estimate their fundamental parameters and the abundances of 16 chemical species in a self-consistent manner. Some powerful probes of mixing are investigated (the Li and CNO abundances, as well as the carbon isotopic ratio in a few cases). The information provided by the spectroscopic and seismic data is combined to provide more accurate physical parameters and abundances. The stars in our sample follow the general abundance trends as a function of the metallicity observed in stars of the Galactic disk. After an allowance is made for the chemical evolution of the interstellar medium, the observational signature of internal mixing phenomena is revealed through the detection at the stellar surface of the products of the CN cycle. A contamination by NeNa-cycled material in the most massive stars is also discussed. With the asteroseismic constraints, these data will pave the way for a detailed theoretical investigation of the physical processes responsible for the transport of chemical elements in evolved, low- and intermediate-mass stars. Based on observations collected at La Silla Observatory, ESO (Chile) with the FEROS and HARPS spectrograph at the 2.2 and 3.6-m telescopes under programs LP178.D-0361, LP182.D-0356, and LP185.D-0056.Appendix A is available in electronic form at http://www.aanda.orgTables A.2 to A.6 are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/564/A119

  20. Rapidly rotating single late-type giants: New FK Comae stars?

    Science.gov (United States)

    Fekel, Francis C.

    1986-01-01

    A group of rapidly rotating single late-type giants was found from surveys of chromospherically active stars. These stars have V sin I's ranging from 6 to 46 km/sec, modest ultraviolet emission line fluxes, and strong H alpha absorption lines. Although certainly chromospherically active, their characteristics are much less extreme than those of FK Com and one or two other similar systems. One possible explanation for the newly identified systems is that they have evolved from stars similar to FK Com. The chromospheric activity and rotation of single giant stars like FK Com would be expected to decrease with time as they do in single dwarfs. Alternatively, this newly identified group may have evolved from single rapidly rotating A, or early F stars.

  1. Surgical treatment of the giant hiatal hernia - A single-center experience

    DEFF Research Database (Denmark)

    Jensen, Jonas Sanberg

    Introduction All symptomatic giant hiatal hernias, defined as any hiatal hernia where more than 30% of the stomach is placed intrathoracically, should be addressed with elective surgery, significantly reducing the risk of complications. Symptoms of incarceration require immediate emergency surgery...... and occur in less than 2% per year. The purpose of this study was to evaluate perioperative data, outcome and patient satisfaction in patients undergoing emergency or planned surgery for giant hiatal hernia in a Danish centre. Methods and Procedures This retrospective study was performed using patient...... records of all patients undergoing emergency (E) or planned (P) primary laparoscopic repair for giant hiatal hernia at a single center over a six-year period. Demographics and characteristics of hiatal hernia and surgery were registered. Admission length, complications and readmission within 30 days were...

  2. TESTING SCALING RELATIONS FOR SOLAR-LIKE OSCILLATIONS FROM THE MAIN SEQUENCE TO RED GIANTS USING KEPLER DATA

    Energy Technology Data Exchange (ETDEWEB)

    Huber, D.; Bedding, T. R.; Stello, D. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Hekker, S. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Mathur, S. [High Altitude Observatory, NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); Mosser, B. [LESIA, CNRS, Universite Pierre et Marie Curie, Universite Denis, Diderot, Observatoire de Paris, 92195 Meudon cedex (France); Verner, G. A.; Elsworth, Y. P.; Hale, S. J.; Chaplin, W. J. [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom); Bonanno, A. [INAF Osservatorio Astrofisico di Catania (Italy); Buzasi, D. L. [Eureka Scientific, 2452 Delmer Street Suite 100, Oakland, CA 94602-3017 (United States); Campante, T. L. [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Kallinger, T. [Department of Physics and Astronomy, University of British Columbia, Vancouver (Canada); Silva Aguirre, V. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany); De Ridder, J. [Instituut voor Sterrenkunde, K.U.Leuven (Belgium); Garcia, R. A. [Laboratoire AIM, CEA/DSM-CNRS, Universite Paris 7 Diderot, IRFU/SAp, Centre de Saclay, 91191, Gif-sur-Yvette (France); Appourchaux, T. [Institut d' Astrophysique Spatiale, UMR 8617, Universite Paris Sud, 91405 Orsay Cedex (France); Frandsen, S. [Danish AsteroSeismology Centre (DASC), Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Houdek, G., E-mail: dhuber@physics.usyd.edu.au [Institute of Astronomy, University of Vienna, 1180 Vienna (Austria); and others

    2011-12-20

    We have analyzed solar-like oscillations in {approx}1700 stars observed by the Kepler Mission, spanning from the main sequence to the red clump. Using evolutionary models, we test asteroseismic scaling relations for the frequency of maximum power ({nu}{sub max}), the large frequency separation ({Delta}{nu}), and oscillation amplitudes. We show that the difference of the {Delta}{nu}-{nu}{sub max} relation for unevolved and evolved stars can be explained by different distributions in effective temperature and stellar mass, in agreement with what is expected from scaling relations. For oscillation amplitudes, we show that neither (L/M){sup s} scaling nor the revised scaling relation by Kjeldsen and Bedding is accurate for red-giant stars, and demonstrate that a revised scaling relation with a separate luminosity-mass dependence can be used to calculate amplitudes from the main sequence to red giants to a precision of {approx}25%. The residuals show an offset particularly for unevolved stars, suggesting that an additional physical dependency is necessary to fully reproduce the observed amplitudes. We investigate correlations between amplitudes and stellar activity, and find evidence that the effect of amplitude suppression is most pronounced for subgiant stars. Finally, we test the location of the cool edge of the instability strip in the Hertzsprung-Russell diagram using solar-like oscillations and find the detections in the hottest stars compatible with a domain of hybrid stochastically excited and opacity driven pulsation.

  3. Rotational and radial velocities of 1.3-2.2 M {sub ☉} red giants in open clusters

    Energy Technology Data Exchange (ETDEWEB)

    Carlberg, Joleen K., E-mail: jcarlberg@dtm.ciw.edu [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States)

    2014-06-01

    This study presents the rotational distribution of red giant (RG) stars in 11 old to intermediate age open clusters. The masses of these stars are all above the Kraft break, so they lose negligible amounts of their birth angular momentum (AM) during the main-sequence (MS) evolution. However, they do span a mass range with quite different AM distributions imparted during formation, with the stars less massive than ∼1.6M {sub ☉} arriving on the MS with lower rotation rates than the more massive stars. The majority of RGs in this study are slow rotators across the entire red giant branch regardless of mass, supporting the picture that intermediate-mass stars rapidly spin down when they evolve off the MS and develop convection zones capable of driving a magnetic dynamo. Nevertheless, a small fraction of RGs in open clusters show some level of enhanced rotation, and faster rotators are as common in these clusters as in the field RG population. Most of these enhanced rotators appear to be red clump stars, which is also true of the underlying stellar sample, while others are clearly RGs that are above or below the clump. In addition to rotational velocities, the radial velocities (RVs) and membership probabilities of individual stars are also presented. Cluster heliocentric RVs for NGC 6005 and Pismis 18 are reported for the first time.

  4. THE ASYMPTOTIC GIANT BRANCH AND THE TIP OF THE RED GIANT BRANCH AS PROBES OF STAR FORMATION HISTORY: THE NEARBY DWARF IRREGULAR GALAXY KKH 98

    International Nuclear Information System (INIS)

    Melbourne, J.; Williams, B.; Dalcanton, J.; Ammons, S. M.; Max, C.; Koo, D. C.; Girardi, Leo; Dolphin, A.

    2010-01-01

    We investigate the utility of the asymptotic giant branch (AGB) and the red giant branch (RGB) as probes of the star formation history (SFH) of the nearby (D = 2.5 Mpc) dwarf irregular galaxy, KKH 98. Near-infrared (near-IR) Keck Laser Guide Star Adaptive Optics (AO) images resolve 592 IR-bright stars reaching over 1 mag below the tip of the RGB. Significantly deeper optical (F475W and F814W) Hubble Space Telescope images of the same field contain over 2500 stars, reaching to the red clump and the main-sequence turnoff for 0.5 Gyr old populations. Compared to the optical color-magnitude diagram (CMD), the near-IR CMD shows significantly tighter AGB sequences, providing a good probe of the intermediate-age (0.5-5 Gyr) populations. We match observed CMDs with stellar evolution models to recover the SFH of KKH 98. On average, the galaxy has experienced relatively constant low-level star formation (5 x 10 -4 M sun yr -1 ) for much of cosmic time. Except for the youngest main-sequence populations (age <0.1 Gyr), which are typically fainter than the AO data flux limit, the SFH estimated from the 592 IR-bright stars is a reasonable match to that derived from the much larger optical data set. Differences between the optical- and IR-derived SFHs for 0.1-1 Gyr populations suggest that current stellar evolution models may be overproducing the AGB by as much as a factor of 3 in this galaxy. At the depth of the AO data, the IR-luminous stars are not crowded. Therefore, these techniques can potentially be used to determine the stellar populations of galaxies at significantly further distances.

  5. Kinematics and Metallicity of M31 Red Giants: The Giant Southern Stream and Discovery of a Second Cold Component at R=20 kpc

    Science.gov (United States)

    Kalirai, Jasonjot S.; Guhathakurta, Puragra; Gilbert, Karoline M.; Reitzel, David B.; Majewski, Steven R.; Rich, R. Michael; Cooper, Michael C.

    2006-04-01

    We present spectroscopic observations of red giant branch (RGB) stars in the Andromeda spiral galaxy (M31), acquired with the DEIMOS instrument on the Keck II 10 m telescope. The three fields targeted in this study are in the M31 spheroid, outer disk, and giant southern stream. In this paper, we focus on the kinematics and chemical composition of RGB stars in the stream field located at a projected distance of R=20 kpc from M31's center. A mix of stellar populations is found in this field. M31 RGB stars are isolated from Milky Way dwarf star contaminants using a variety of spectral and photometric diagnostics. The radial velocity distribution of RGB stars displays a clear bimodality-a primary peak centered at v¯1=-513 km s-1 and a secondary one at v¯2=-417 km s-1-along with an underlying broad component that is presumably representative of the smooth spheroid of M31. Both peaks are found to be dynamically cold with intrinsic velocity dispersions of σ(v)~16 km s-1. The mean metallicity and metallicity dispersion of stars in the two peaks is also found to be similar: ~-0.45 and σ([Fe/H])=0.2. The observed velocity of the primary peak is consistent with that predicted by dynamical models for the stream, but there is no obvious explanation for the secondary peak. The nature of the secondary cold population is unclear: it may represent (1) tidal debris from a satellite merger event that is superimposed on, but unrelated to, the giant southern stream; (2) a wrapped around component of the giant southern stream; or (3) a warp or overdensity in M31's disk at Rdisk>50 kpc (this component is well above the outward extrapolation of the smooth exponential disk brightness profile). Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous

  6. High-resolution spectra of stars in globular clusters. VI - Oxygen-deficient red giant stars in M13

    International Nuclear Information System (INIS)

    Brown, J.A.; Wallerstein, G.; Oke, J.B.

    1991-01-01

    From high-resolution, high signal-to-noise spectra, abundances of carbon, nitrogen, and oxygen and the C-12/C-13 ratio for five red giants in M13, including star II-67, which has previously been reported to be deficient in oxygen have been determined. Three of the five stars exhibit substantial oxygen deficiencies; O/Fe values range from +0.5 to less than about 0.3. The sum of the CNO nuclides is the same for all stars, which is interpreted as evidence that mixing of CNO-cycled material into the envelope is the cause of the variations in oxygen abundance. 41 refs

  7. Particle decays in /sup 28/Si: The destruction of /sup 27/Al in red giants and novae

    Energy Technology Data Exchange (ETDEWEB)

    Champagne, A E; Cella, C H; Kouzes, R T; Lowry, M M; Magnus, P V; Smith, M S; Mao, Z Q

    1988-10-10

    The /sup 27/Al(/sup 3/He,d)/sup 28/Si reaction has been used to populate states near the /sup 27/Al+p threshold and the ensuing proton and alpha decay has been measured. No evidence for new /sup 27/Al(p,..cap alpha..)/sup 24/Mg resonance strength was observed and consequently revised limits have been placed on the thermonuclear reaction rate. As a result, the /sup 27/Al(p,..cap alpha..)/sup 24/Mg reaction is found to be astrophysically unimportant at red-giant and nova temperatures.

  8. The chemical composition of red giants in 47 Tucanae. I. Fundamental parameters and chemical abundance patterns

    Science.gov (United States)

    Thygesen, A. O.; Sbordone, L.; Andrievsky, S.; Korotin, S.; Yong, D.; Zaggia, S.; Ludwig, H.-G.; Collet, R.; Asplund, M.; Ventura, P.; D'Antona, F.; Meléndez, J.; D'Ercole, A.

    2014-12-01

    Context. The study of chemical abundance patterns in globular clusters is key importance to constraining the different candidates for intracluster pollution of light elements. Aims: We aim at deriving accurate abundances for a wide range of elements in the globular cluster 47 Tucanae (NGC 104) to add new constraints to the pollution scenarios for this particular cluster, expanding the range of previously derived element abundances. Methods: Using tailored 1D local thermodynamic equilibrium (LTE) atmospheric models, together with a combination of equivalent width measurements, LTE, and NLTE synthesis, we derive stellar parameters and element abundances from high-resolution, high signal-to-noise spectra of 13 red giant stars near the tip of the RGB. Results: We derive abundances of a total 27 elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ru, Ba, La, Ce, Pr, Nd, Eu, Dy). Departures from LTE were taken into account for Na, Al, and Ba. We find a mean [Fe/H] = -0.78 ± 0.07 and [ α/ Fe ] = 0.34 ± 0.03 in good agreement with previous studies. The remaining elements show good agreement with the literature, but including NLTE for Al has a significant impact on the behavior of this key element. Conclusions: We confirm the presence of an Na-O anti-correlation in 47 Tucanae found by several other works. Our NLTE analysis of Al shifts the [Al/Fe] to lower values, indicating that this may be overestimated in earlier works. No evidence of an intrinsic variation is found in any of the remaining elements. Based on observations made with the ESO Very Large Telescope at Paranal Observatory, Chile (Programmes 084.B-0810 and 086.B-0237).Full Tables 2, 5, and 9 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/A108Appendix A is available in electronic form at http://www.aanda.org

  9. A new photometric model of the Galactic bar using red clump giants

    Science.gov (United States)

    Cao, Liang; Mao, Shude; Nataf, David; Rattenbury, Nicholas J.; Gould, Andrew

    2013-09-01

    We present a study of the luminosity density distribution of the Galactic bar using number counts of red clump giants from the Optical Gravitational Lensing Experiment (OGLE) III survey. The data were recently published by Nataf et al. for 9019 fields towards the bulge and have 2.94 × 106 RC stars over a viewing area of 90.25 deg^2. The data include the number counts, mean distance modulus (μ), dispersion in μ and full error matrix, from which we fit the data with several triaxial parametric models. We use the Markov Chain Monte Carlo method to explore the parameter space and find that the best-fitting model is the E3 model, with the distance to the GC 8.13 kpc, the ratio of semimajor and semiminor bar axis scalelengths in the Galactic plane x0, y0 and vertical bar scalelength z0 x0: y0: z0 ≈ 1.00: 0.43: 0.40 (close to being prolate). The scalelength of the stellar density profile along the bar's major axis is ˜0.67 kpc and has an angle of 29.4°, slightly larger than the value obtained from a similar study based on OGLE-II data. The number of estimated RC stars within the field of view is 2.78 × 106, which is systematically lower than the observed value. We subtract the smooth parametric model from the observed counts and find that the residuals are consistent with the presence of an X-shaped structure in the Galactic Centre, the excess to the estimated mass content is ˜5.8 per cent. We estimate that the total mass of the bar is ˜1.8 × 1010 M⊙. Our results can be used as a key ingredient to construct new density models of the Milky Way and will have implications on the predictions of the optical depth to gravitational microlensing and the patterns of hydrodynamical gas flow in the Milky Way.

  10. Giant current fluctuations in an overheated single-electron transistor

    Science.gov (United States)

    Laakso, M. A.; Heikkilä, T. T.; Nazarov, Yuli V.

    2010-11-01

    Interplay of cotunneling and single-electron tunneling in a thermally isolated single-electron transistor leads to peculiar overheating effects. In particular, there is an interesting crossover interval where the competition between cotunneling and single-electron tunneling changes to the dominance of the latter. In this interval, the current exhibits anomalous sensitivity to the effective electron temperature of the transistor island and its fluctuations. We present a detailed study of the current and temperature fluctuations at this interesting point. The methods implemented allow for a complete characterization of the distribution of the fluctuating quantities, well beyond the Gaussian approximation. We reveal and explore the parameter range where, for sufficiently small transistor islands, the current fluctuations become gigantic. In this regime, the optimal value of the current, its expectation value, and its standard deviation differ from each other by parametrically large factors. This situation is unique for transport in nanostructures and for electron transport in general. The origin of this spectacular effect is the exponential sensitivity of the current to the fluctuating effective temperature.

  11. Characteristics of solar-like oscillations in red giants observed in the CoRoT exoplanet field

    Science.gov (United States)

    Hekker, S.; Kallinger, T.; Baudin, F.; De Ridder, J.; Barban, C.; Carrier, F.; Hatzes, A. P.; Weiss, W. W.; Baglin, A.

    2009-10-01

    Context: Observations during the first long run (~150 days) in the exo-planet field of CoRoT increase the number of G-K giant stars for which solar-like oscillations are observed by a factor of 100. This opens the possibility to study the characteristics of their oscillations in a statistical sense. Aims: We aim to understand the statistical distribution of the frequencies of maximum oscillation power (ν_max) in red giants and to search for a possible correlation between ν_max and the large separation (Δ ν). Methods: Red giants with detectable solar-like oscillations are identified using both semi-automatic and manual procedures. For these stars, we determine ν_max as the centre of a Gaussian fit to the oscillation power excess. For the determination of Δ ν, we use the autocorrelation of the Fourier spectra, the comb response function and the power spectrum of the power spectrum. Results: The resulting ν_max distribution shows a pronounced peak between 20-40 μHz. For about half of the stars we obtain Δ ν with at least two methods. The correlation between ν_max and Δ ν follows the same scaling relation as inferred for solar-like stars. Conclusions: The shape of the ν_max distribution can partly be explained by granulation at low frequencies and by white noise at high frequencies, but the population density of the observed stars turns out to be also an important factor. From the fact that the correlation between Δ ν and ν_max for red giants follows the same scaling relation as obtained for sun-like stars, we conclude that the sound travel time over the pressure scale height of the atmosphere scales with the sound travel time through the whole star irrespective of evolution. The fraction of stars for which we determine Δ ν does not correlate with ν_max in the investigated frequency range, which confirms theoretical predictions. The CoRoT space mission which was developed and is operated by the French space agency CNES, with participation of ESA

  12. Convective heating of the inner core of red giants prior to the peak of the core helium flash

    International Nuclear Information System (INIS)

    Cole, P.W.; Demarque, P.; Deupree, R.G.

    1985-01-01

    The effects of convective overshooting across the temperature inversion in the cores of red giants are investigated from the onset of the core convection zone to the peak of the core helium flash using a model for overshooting in stellar evolution, based on two-dimensional and three-dimensional hydrodynamic simulations of the core helium flash. A major effect of the overshooting is the substantial heating of the material interior to the temperature inversion, producing a smoother temperature profile. This interior heating is thus unimportant until approximately 1 week preceding the time of maximum temperature, but then produces temperature changes on a time scale short with respect to the evolution time scale. Interior heating (1) alters the standard relation of the maximum temperature and the density at the point of maximum temperature, (2) makes the maximum temperature occur at a smaller mass fraction, (3) causes the time of maximum temperature to occur hundreds of years earlier in the red giant evolution, and (4) redistributes the mass from the location of maximum temperature. Since the degree of degeneracy is known to affect the violence of the flash in the hydrodynamic phase, internal heating may play an important role in determining the subsequent evolution of the core

  13. DISCOVERY OF A RED GIANT WITH SOLAR-LIKE OSCILLATIONS IN AN ECLIPSING BINARY SYSTEM FROM KEPLER SPACE-BASED PHOTOMETRY

    International Nuclear Information System (INIS)

    Hekker, S.; Debosscher, J.; De Ridder, J.; Aerts, C.; Van Winckel, H.; Beck, P. G.; Blomme, J.; Huber, D.; Hidas, M. G.; Stello, D.; Bedding, T. R.; Gilliland, R. L.; Christensen-Dalsgaard, J.; Kjeldsen, H.; Brown, T. M.; Borucki, W. J.; Koch, D.; Jenkins, J. M.; Southworth, J.; Pigulski, A.

    2010-01-01

    Oscillating stars in binary systems are among the most interesting stellar laboratories, as these can provide information on the stellar parameters and stellar internal structures. Here we present a red giant with solar-like oscillations in an eclipsing binary observed with the NASA Kepler satellite. We compute stellar parameters of the red giant from spectra and the asteroseismic mass and radius from the oscillations. Although only one eclipse has been observed so far, we can already determine that the secondary is a main-sequence F star in an eccentric orbit with a semi-major axis larger than 0.5 AU and orbital period longer than 75 days.

  14. Kuwano's peculiar object is a novalike (symbiotic) binary with a red giant. Discussion of observational results

    International Nuclear Information System (INIS)

    Belyakina, T.S.; Gershberg, R.E.; Efimov, Yu.S.; Krasnobabtsev, V.I.; Pavlenko, E.P.; Petrov, P.P.; Chuvaev, K.K.; Shenavrin, V.I.

    1982-01-01

    Photometric, polarimetric and spectral observations carried out at the Crimea permit to conclude that the Kuwano object is a binary system that consists of an M-giant and of a low-luminosity star. During the 1979 flare, the absolute magnitude of the weak component has increased up to about -6sup(m), the M-giant had apparently small variations as well. A distance to the object is estimated to be 5-7 kpc, and it is located certainly out of the galactic plane. Similarities between the Kuwano object and slow novae and symbiotic stars are noted [ru

  15. Giant coercivity in ferromagnetic Co doped ZnO single crystal thin film

    International Nuclear Information System (INIS)

    Loukya, B.; Negi, D.S.; Dileep, K.; Kumar, N.; Ghatak, Jay; Datta, R.

    2013-01-01

    The origin of ferromagnetism in ZnO doped with transition metal impurities has been discussed extensively and appeared to be a highly controversial and challenging topic in today's solid state physics. Magnetism observed in this system is generally weak and soft. We have grown Co:ZnO up to 30 at% Co in single crystal thin film form on c-plane sapphire. A composition dependent coercivity is observed in this system which reaches peak value at 25 at% Co, the values are 860 Oe and 1149 Oe with applied field along parallel and perpendicular to the film substrate interface respectively. This giant coercivity might pave the way to exploit this material as a magnetic semiconductor with novel logic functionalities. The findings are explained based on defect band itinerant ferromagnetism and its partial interaction with localized d electrons of Co through charge transfer. Besides large coercivity, an increase in the band gap with Co concentration has also been observed along with blue emission peak with long tail confirming the formation of extended point defect levels in the host lattice band gap. - Highlights: • Co doped ZnO ferromagnetic single crystal thin film. • Giant coercivity in Co:ZnO thin film which may help to turn this material into application. • Cathodoluminescence (CL) data showing increase in band gap with Co concentrations. • A theoretical proposal is made to explain the observed giant coercivity

  16. Quantum chaos in nuclear single-particle motion and damping of giant resonances

    International Nuclear Information System (INIS)

    Pal, Santanu; Mukhopadhyay, Tapan

    1995-01-01

    The spectral statistics of single particle motion in deformed cavities with axial symmetry are presented. The single particle motion in the cavities considered are non-integrable and the systematics of the fluctuation measures of the spectra reveal a transition from regular to chaotic regime in the corresponding classical systems. Quantitative estimate of the degree of chaos enables us to introduce a correction factor to the one-body wall formula for the damping widths of isoscalar giant resonances. The damping widths calculated with this correction factor give much better agreement with experimental values than earlier calculations of one-body damping widths. (author). 21 refs., 5 figs

  17. Models of red giants in the CoRoT asteroseismology fields combining asteroseismic and spectroscopic constraints - The open cluster NGC 6633 and field stars-

    Science.gov (United States)

    Lagarde, Nadège; Miglio, Andrea; Eggenberger, Patrick; Morel, Thierry; Montalbàn, Josefina; Mosser, Benoit

    2015-08-01

    The availability of asteroseismic constraints for a large sample of red giant stars from the CoRoT and Kepler missions paves the way for various statistical studies of the seismic properties of stellar populations.We use the first detailed spectroscopic study of CoRoT red-giant stars (Morel et al 2014) to compare theoretical stellar evolution models to observations of the open cluster NGC 6633 and field stars.In order to explore the effects of rotation-induced mixing and thermohaline instability, we compare surface abundances of carbon isotopic ratio and lithium with stellar evolution predictions. These chemicals are sensitive to extra-mixing on the red-giant branch.We estimate mass, radius, and distance for each star using the seismic constraints. We note that the Hipparcos and seismic distances are different. However, the uncertainties are such that this may not be significant. Although the seismic distances for the cluster members are self consistent they are somewhat larger than the Hipparcos distance. This is an issue that should be considered elsewhere. Models including thermohaline instability and rotation-induced mixing, together with the seismically determined masses can explain the chemical properties of red-giants targets. Tighter constraints on the physics of the models would be possible if there were detailed knowledge of the core rotation rate and the asymptotic period spacing.

  18. Discovery of a Red Giant with Solar-like Oscillations in an Eclipsing Binary System from Kepler Space-based Photometry

    DEFF Research Database (Denmark)

    Hekker, S.; Debosscher, J.; Huber, D.

    2010-01-01

    Oscillating stars in binary systems are among the most interesting stellar laboratories, as these can provide information on the stellar parameters and stellar internal structures. Here we present a red giant with solar-like oscillations in an eclipsing binary observed with the NASA Kepler...

  19. THREE DISCRETE GROUPS WITH HOMOGENEOUS CHEMISTRY ALONG THE RED GIANT BRANCH IN THE GLOBULAR CLUSTER NGC 2808

    International Nuclear Information System (INIS)

    Carretta, E.

    2014-01-01

    We present the homogeneous reanalysis of Mg and Al abundances from high resolution UVES/FLAMES spectra for 31 red giants in the globular cluster NGC 2808. We found a well defined Mg-Al anticorrelation reaching a regime of subsolar Mg abundance ratios, with a spread of about 1.4 dex in [Al/Fe]. The main result from the improved statistics of our sample is that the distribution of stars is not continuous along the anticorrelation because they are neatly clustered into three distinct clumps, each with different chemical compositions. One group (P) shows a primordial composition of field stars of similar metallicity, and the other two (I and E) have increasing abundances of Al and decreasing abundances of Mg. The fraction of stars we found in the three components (P: 68%, I: 19%, E: 13%) is in excellent agreement with the ratios computed for the three distinct main sequences in NGC 2808: for the first time there is a clear correspondence between discrete photometric sequences of dwarfs and distinct groups of giants with homogeneous chemistry. The composition of the I group cannot be reproduced by mixing of matter with extreme processing in hot H-burning and gas with pristine, unprocessed composition, as also found in the recent analysis of three discrete groups in NGC 6752. This finding suggests that different classes of polluters were probably at work in NGC 2808 as well

  20. The JHKs Magnitudes of the Red Giant Branch Tip and the Distance Moduli of Nearby Dwarf Galaxy NGC 205

    Directory of Open Access Journals (Sweden)

    M. Y. Jung

    2009-12-01

    Full Text Available We have used the near-infrared JHKS photometric data of resolved stars in a nearby dwarf elliptical galaxy NGC 205 to determine the magnitudes of the red giant branch tip (TRGB. By applying Savitzky-Golay filter to the observed luminosity functions (LFs in each band, we derived the second derivatives of the LFs so as to determine the magnitudes of the TRGB. Absolute magnitudes of the TRGB in JHKs bands were measured from the Yonsei-Yale isochrones. By comparing the determined apparent magnitudes and the theoretical absolute magnitudes of the TRGB, we estimated the distance moduli of NGC 205 to be (m-M = 24.10±0:08, 24.08±0.12 and 24.14±0.14 in J, H, and Ks bands, respectively.

  1. STAR-TO-STAR IRON ABUNDANCE VARIATIONS IN RED GIANT BRANCH STARS IN THE GALACTIC GLOBULAR CLUSTER NGC 3201

    International Nuclear Information System (INIS)

    Simmerer, Jennifer; Ivans, Inese I.; Filler, Dan; Francois, Patrick; Charbonnel, Corinne; Monier, Richard; James, Gaël

    2013-01-01

    We present the metallicity as traced by the abundance of iron in the retrograde globular cluster NGC 3201, measured from high-resolution, high signal-to-noise spectra of 24 red giant branch stars. A spectroscopic analysis reveals a spread in [Fe/H] in the cluster stars at least as large as 0.4 dex. Star-to-star metallicity variations are supported both through photometry and through a detailed examination of spectra. We find no correlation between iron abundance and distance from the cluster core, as might be inferred from recent photometric studies. NGC 3201 is the lowest mass halo cluster to date to contain stars with significantly different [Fe/H] values.

  2. Star-to-star Iron Abundance Variations in Red Giant Branch Stars in the Galactic Globular Cluster NGC 3201

    Science.gov (United States)

    Simmerer, Jennifer; Ivans, Inese I.; Filler, Dan; Francois, Patrick; Charbonnel, Corinne; Monier, Richard; James, Gaël

    2013-02-01

    We present the metallicity as traced by the abundance of iron in the retrograde globular cluster NGC 3201, measured from high-resolution, high signal-to-noise spectra of 24 red giant branch stars. A spectroscopic analysis reveals a spread in [Fe/H] in the cluster stars at least as large as 0.4 dex. Star-to-star metallicity variations are supported both through photometry and through a detailed examination of spectra. We find no correlation between iron abundance and distance from the cluster core, as might be inferred from recent photometric studies. NGC 3201 is the lowest mass halo cluster to date to contain stars with significantly different [Fe/H] values.

  3. The Near-infrared Tip of the Red Giant Branch. I. A Calibration in the Isolated Dwarf Galaxy IC 1613

    Science.gov (United States)

    Madore, Barry F.; Freedman, Wendy L.; Hatt, Dylan; Hoyt, Taylor J.; Monson, Andrew J.; Beaton, Rachael L.; Rich, Jeffrey A.; Jang, In Sung; Lee, Myung Gyoon; Scowcroft, Victoria; Seibert, Mark

    2018-05-01

    Based on observations from the FourStar near-infrared camera on the 6.5 m Baade-Magellan telescope at Las Campanas, Chile, we present calibrations of the JHK luminosities of stars defining the tip of the red giant branch (TRGB) in the halo of the Local Group dwarf galaxy IC 1613. We employ metallicity-independent (rectified) T-band magnitudes—constructed using J-, H-, and K-band magnitudes and both (J ‑ H) and (J ‑ K) colors to flatten the upward-sloping red giant branch tips as otherwise seen in their apparent color–magnitude diagrams. We describe and quantify the advantages of working at these particular near-infrared wavelengths, which are applicable to both the Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST). We also note that these same wavelengths can be accessed from the ground for an eventual tie-in to Gaia for absolute astrometry and parallaxes to calibrate the intrinsic luminosity of the TRGB. Adopting the color terms derived from the IC 1613 data, as well as the zero points from a companion study of the Large Magellanic Cloud, whose distance is anchored to the geometric distances of detached eclipsing binaries, we find a true distance modulus of 24.32 ± 0.02 (statistical) ±0.05 mag (systematic) for IC 1613, which compares favorably with the recently published multi-wavelength, multi-method consensus modulus of 24.30 ± 0.05 mag by Hatt et al.

  4. Giant anisotropy of magnetocaloric effect in TbMnO3 single crystals

    Science.gov (United States)

    Jin, Jin-Ling; Zhang, Xiang-Qun; Li, Guo-Ke; Cheng, Zhao-Hua; Zheng, Lin; Lu, Yi

    2011-05-01

    The magnetocaloric effect (MCE) in TbMnO3 single crystals was investigated by isothermal magnetization curves for the ab plane at low temperatures. Large magnetic entropy change, ΔSM = -18.0 J/kg K, and the refrigerant capacity, RC = 390.7 J/kg, are achieved near the ordering temperature of Tb3+ moment (TNTb) under 70 kOe along the a axis. Furthermore, the TbMnO3 single crystal exhibits a giant MCE anisotropy. The difference of ΔSMand RC between the a and b axes is field and temperature dependent, which reaches maximum values of 11.4 J/kg K and 304.1 J/kg, respectively. By taking magnetocrystalline anisotropy into account, the rotating ΔSMwithin the ab plane can be well simulated, indicating that the anisotropy of ΔSMis directly contributed from the magnetocrystalline anisotropy. Our finding for giant MCE anisotropy in TbMnO3 single crystals explores the possibility of using this material for magnetic refrigerators by rotating its magnetization vector rather than moving it in and out of the magnet.

  5. Single-cell measurement of red blood cell oxygen affinity.

    Science.gov (United States)

    Di Caprio, Giuseppe; Stokes, Chris; Higgins, John M; Schonbrun, Ethan

    2015-08-11

    Oxygen is transported throughout the body by hemoglobin (Hb) in red blood cells (RBCs). Although the oxygen affinity of blood is well-understood and routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of RBC volume and Hb concentration are taken millions of times per day by clinical hematology analyzers, and they are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume, and Hb concentration for individual RBCs in high throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.9%, which corresponds to the maximum slope of the oxygen-Hb dissociation curve. In addition, single-cell oxygen affinity is positively correlated with Hb concentration but independent of osmolarity, which suggests variation in the Hb to 2,3-diphosphoglycerate (2-3 DPG) ratio on a cellular level. By quantifying the functional behavior of a cellular population, our system adds a dimension to blood cell analysis and other measurements of single-cell variability.

  6. Magnetization tunneling in high-symmetry single-molecule magnets: Limitations of the giant spin approximation

    Science.gov (United States)

    Wilson, A.; Lawrence, J.; Yang, E.-C.; Nakano, M.; Hendrickson, D. N.; Hill, S.

    2006-10-01

    Electron paramagnetic resonance (EPR) studies of a Ni4 single-molecule magnet (SMM) yield the zero-field-splitting (ZFS) parameters D , B40 , and B44 , based on the giant spin approximation (GSA) with S=4 ; B44 is responsible for the magnetization tunneling in this SMM. Experiments on an isostructural Ni-doped Zn4 crystal establish the NiII ion ZFS parameters. The fourth-order ZFS parameters in the GSA arise from the interplay between the Heisenberg interaction Jŝ1•ŝ2 and the second-order single-ion anisotropy, giving rise to mixing of higher-lying S≠4 states into the S=4 state. Consequently, J directly influences the ZFS in the ground state, enabling its determination by EPR.

  7. The Carnegie–Chicago Hubble Program. III. The Distance to NGC 1365 via the Tip of the Red Giant Branch

    Science.gov (United States)

    Jang, In Sung; Hatt, Dylan; Beaton, Rachael L.; Lee, Myung Gyoon; Freedman, Wendy L.; Madore, Barry F.; Hoyt, Taylor J.; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark

    2018-01-01

    The Carnegie–Chicago Hubble Program (CCHP) seeks to anchor the distance scale of Type Ia supernovae via the Tip of the Red Giant Branch (TRGB) method. Based on deep Hubble Space Telescope ACS/WFC imaging, we present an analysis of the TRGB for the metal-poor halo of NGC 1365, a giant spiral galaxy in the Fornax cluster that was host to the Type Ia supernova SN 2012fr. We have measured the extinction-corrected TRGB magnitude of NGC 1365 to be F814W = 27.34 ± 0.03stat ± 0.04sys mag. In advance of future direct calibration by Gaia, we adopt a provisional I-band TRGB luminosity set at the Large Magellanic Cloud and find a true distance modulus μ 0 = 31.29 ± 0.04stat ± 0.06sys mag or D = 18.1 ± 0.3stat ± 0.5sys Mpc. This measurement is in excellent agreement with recent Cepheid-based distances to NGC 1365 and reveals no significant difference in the distances derived from stars of Populations I and II for this galaxy. We revisit the error budget for the CCHP path to the Hubble constant based on the analysis presented here, i.e., that for one of the most distant Type Ia supernova hosts within our Program, and find that a 2.5% measurement is feasible with the current sample of galaxies and TRGB absolute calibration. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13691.

  8. Modeling of Red Giant and AGB Stars Atmospheres: Constraints from VLTI and HST Observations

    Science.gov (United States)

    Rau, Gioia

    2018-04-01

    The chemical enrichment of the Universe is considerably affected by the contributions of low-to-intermediate mass stars through the mass-loss provided via their stellar winds. First, we will present our investigation in the near-IR with VLTI/GRAVITY (Wittkowski, Rau, et al., in prep.). Our aim was to verify at different epochs the model-predicted variability of the visibility spectra. We use CODEX model atmospheres, as well as best-fit 3D radiation hydrodynamic simulations (e.g. Freytag et al., 2017), for comparison with the observations. Our preliminary results on R Peg suggest a decreasing contribution by extended CO layers as the star transitions from maximum to minimum phase. Second, we will show a preliminary modeling of UV spectra obtained with HST/GHRS that contain chromospheric emission lines of, e.g., Mg II and Fe II. Via Sobolev with Exact Integration (SEI) modeling, we determined for the two M-giant stars γ Cru and µ Gem the characteristics of their winds (turbulence, acceleration, and opacity), and their average global mass-loss rates (Rau, Carpenter et al., in prep.). Finally, we briefly discuss the impact of instruments on board JWST in progressing this investigation.

  9. A white dwarf companion to the main-sequence star 4 Omicron(1) Orionis and the binary hypothesis for the origin of peculiar red giants

    Science.gov (United States)

    Ake, Thomas B.; Johnson, Hollis R.

    1988-01-01

    Ultraviolet spectra of the peculiar red giants (PRGs) called MS stars are investigated, and the discovery of a white dwarf (WD) companion to the MS star 4 Omicron(1) Orionis is reported. The observations and data analysis are discussed and compared with those for field WDs in order to derive parameters for the WD and the luminosity of the primary. Detection limits for the other MS stars investigated are derived, and the binary hypothesis for PRGs is reviewed.

  10. Disruption of a red giant star by a supermassive black hole and the case of PS1-10jh

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanović, Tamara; Cheng, Roseanne M. [Center for Relativistic Astrophysics, School of Physics, Georgia Tech, Atlanta, GA 30332 (United States); Amaro-Seoane, Pau, E-mail: tamarab@gatech.edu, E-mail: rcheng@gatech.edu, E-mail: Pau.Amaro-Seoane@aei.mpg.de [Max Planck Institut für Gravitationsphysik (Albert-Einstein-Institut), D-14476 Potsdam (Germany)

    2014-06-20

    The development of a new generation of theoretical models for tidal disruptions is timely, as increasingly diverse events are being captured in surveys of the transient sky. Recently, Gezari et al. reported a discovery of a new class of tidal disruption events: the disruption of a helium-rich stellar core, thought to be a remnant of a red giant (RG) star. Motivated by this discovery and in anticipation of others, we consider tidal interaction of an RG star with a supermassive black hole (SMBH) which leads to the stripping of the stellar envelope and subsequent inspiral of the compact core toward the black hole. Once the stellar envelope is removed the inspiral of the core is driven by tidal heating as well as the emission of gravitational radiation until the core either falls into the SMBH or is tidally disrupted. In the case of the tidal disruption candidate PS1-10jh, we find that there is a set of orbital solutions at high eccentricities in which the tidally stripped hydrogen envelope is accreted by the SMBH before the helium core is disrupted. This places the RG core in a portion of parameter space where strong tidal heating can lift the degeneracy of the compact remnant and disrupt it before it reaches the tidal radius. We consider how this sequence of events explains the puzzling absence of the hydrogen emission lines from the spectrum of PS1-10jh and gives rise to its other observational features.

  11. Disruption of a red giant star by a supermassive black hole and the case of PS1-10jh

    International Nuclear Information System (INIS)

    Bogdanović, Tamara; Cheng, Roseanne M.; Amaro-Seoane, Pau

    2014-01-01

    The development of a new generation of theoretical models for tidal disruptions is timely, as increasingly diverse events are being captured in surveys of the transient sky. Recently, Gezari et al. reported a discovery of a new class of tidal disruption events: the disruption of a helium-rich stellar core, thought to be a remnant of a red giant (RG) star. Motivated by this discovery and in anticipation of others, we consider tidal interaction of an RG star with a supermassive black hole (SMBH) which leads to the stripping of the stellar envelope and subsequent inspiral of the compact core toward the black hole. Once the stellar envelope is removed the inspiral of the core is driven by tidal heating as well as the emission of gravitational radiation until the core either falls into the SMBH or is tidally disrupted. In the case of the tidal disruption candidate PS1-10jh, we find that there is a set of orbital solutions at high eccentricities in which the tidally stripped hydrogen envelope is accreted by the SMBH before the helium core is disrupted. This places the RG core in a portion of parameter space where strong tidal heating can lift the degeneracy of the compact remnant and disrupt it before it reaches the tidal radius. We consider how this sequence of events explains the puzzling absence of the hydrogen emission lines from the spectrum of PS1-10jh and gives rise to its other observational features.

  12. New asteroseismic scaling relations based on the Hayashi track relation applied to red giant branch stars in NGC 6791 and NGC 6819

    International Nuclear Information System (INIS)

    Wu, T.; Li, Y.; Hekker, S.

    2014-01-01

    Stellar mass M, radius R, and gravity g are important basic parameters in stellar physics. Accurate values for these parameters can be obtained from the gravitational interaction between stars in multiple systems or from asteroseismology. Stars in a cluster are thought to be formed coevally from the same interstellar cloud of gas and dust. The cluster members are therefore expected to have some properties in common. These common properties strengthen our ability to constrain stellar models and asteroseismically derived M, R, and g when tested against an ensemble of cluster stars. Here we derive new scaling relations based on a relation for stars on the Hayashi track (√(T eff )∼g p R q ) to determine the masses and metallicities of red giant branch stars in open clusters NGC 6791 and NGC 6819 from the global oscillation parameters Δν (the large frequency separation) and ν max (frequency of maximum oscillation power). The Δν and ν max values are derived from Kepler observations. From the analysis of these new relations we derive: (1) direct observational evidence that the masses of red giant branch stars in a cluster are the same within their uncertainties, (2) new methods to derive M and z of the cluster in a self-consistent way from Δν and ν max , with lower intrinsic uncertainties, and (3) the mass dependence in the Δν - ν max relation for red giant branch stars.

  13. Infrared extinction in the inner Milky Way through red clump giants

    International Nuclear Information System (INIS)

    González-Fernández, C.; Asensio Ramos, A.; Garzón, F.; Cabrera-Lavers, A.; Hammersley, P. L.

    2014-01-01

    While the shape of the extinction curve in the infrared is considered to be set and the extinction ratios between infrared bands are usually taken to be approximately constant, a number of recent studies point to either a spatially variable behavior of the exponent of the power law or a different extinction law altogether. In this paper, we propose a method to analyze the overall behavior of the interstellar extinction by means of the red-clump population, and we apply it to those areas of the Milky Way where the presence of interstellar matter is heavily felt: areas located in 5° < l < 30° and b = 0°. We show that the extinction ratios traditionally used for the near infrared could be inappropriate for the inner Galaxy and we analyze the behavior of the extinction law from 1 μm to 8 μm.

  14. Infrared extinction in the inner Milky Way through red clump giants

    Energy Technology Data Exchange (ETDEWEB)

    González-Fernández, C.; Asensio Ramos, A.; Garzón, F.; Cabrera-Lavers, A.; Hammersley, P. L., E-mail: carlos.gonzalez@ua.es [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

    2014-02-20

    While the shape of the extinction curve in the infrared is considered to be set and the extinction ratios between infrared bands are usually taken to be approximately constant, a number of recent studies point to either a spatially variable behavior of the exponent of the power law or a different extinction law altogether. In this paper, we propose a method to analyze the overall behavior of the interstellar extinction by means of the red-clump population, and we apply it to those areas of the Milky Way where the presence of interstellar matter is heavily felt: areas located in 5° < l < 30° and b = 0°. We show that the extinction ratios traditionally used for the near infrared could be inappropriate for the inner Galaxy and we analyze the behavior of the extinction law from 1 μm to 8 μm.

  15. Impact of red giant/AGB winds on active galactic nucleus jet propagation

    Science.gov (United States)

    Perucho, M.; Bosch-Ramon, V.; Barkov, M. V.

    2017-10-01

    Context. Dense stellar winds may mass-load the jets of active galactic nuclei, although it is unclear on what time and spatial scales the mixing takes place. Aims: Our aim is to study the first steps of the interaction between jets and stellar winds, and also the scales on which the stellar wind mixes with the jet and mass-loads it. Methods: We present a detailed 2D simulation - including thermal cooling - of a bubble formed by the wind of a star designed to study the initial stages of jet-star interaction. We also study the first interaction of the wind bubble with the jet using a 3D simulation in which the star enters the jet. Stability analysis is carried out for the shocked wind structure to evaluate the distances over which the jet-dragged wind, which forms a tail, can propagate without mixing with the jet flow. Results.The 2D simulations point to quick wind bubble expansion and fragmentation after about one bubble shock crossing time. Three-dimensional simulations and stability analysis point to local mixing in the case of strong perturbations and relatively low density ratios between the jet and the jet dragged-wind, and to a possibly more stable shocked wind structure at the phase of maximum tail mass flux. Analytical estimates also indicate that very early stages of the star jet-penetration time may be also relevant for mass-loading. The combination of these and previous results from the literature suggests highly unstable interaction structures and efficient wind-jet flow mixing on the scale of the jet interaction height. Conclusions: The winds of stars with strong mass loss can efficiently mix with jets from active galactic nuclei. In addition, the initial wind bubble shocked by the jet leads to a transient, large interaction surface. The interaction between jets and stars can produce strong inhomogeneities within the jet. As mixing is expected to be effective on large scales, even individual asymptotic giant branch stars can significantly contribute to

  16. {sup 99} {sup m}Tc-sulphur-colloid and heat-denatured {sup 99} {sup m}Tc-labelled red cell scans demonstrating a giant intrapelvic spleen in a girl after splenectomy

    Energy Technology Data Exchange (ETDEWEB)

    Kao, P.F. [Dept. of Nuclear Medicine, Chang Gung Memorial Hospital and Chang Gung University School of Medicine, Tauyuan, Taiwan (Taiwan); Dept. of Nuclear Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan (Taiwan); Tzen, K.Y.; Tsai, M.F. [Dept. of Nuclear Medicine, Chang Gung Memorial Hospital and Chang Gung University School of Medicine, Tauyuan, Taiwan (Taiwan); Lin, J.N. [Dept. of Paediatric Surgery, Chang Gung Childrens Hospital and Chang Gung University School of Medicine, Tauyuan, Taiwan (Taiwan)

    2001-04-01

    A 17 x 12 x 5-cm giant intrapelvic mass in a 14-year-old girl is reported. This mass developed 6 years after a splenectomy for splenic torsion. The heat-denatured {sup 99} {sup m}Tc-labelled red cell scan and {sup 99} {sup m}Tc- sulphur-colloid scan confirmed the specific red cell sequestration function and reticuloendothelial activity in the giant intrapelvic spleen. The size and development of the giant intrapelvic spleen are unusual. The usefulness of functional images to diagnosis the nature of the intrapelvic mass is well demonstrated. (orig.)

  17. PROBING THE DEEP END OF THE MILKY WAY WITH KEPLER : ASTEROSEISMIC ANALYSIS OF 854 FAINT RED GIANTS MISCLASSIFIED AS COOL DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, S. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); García, R. A.; Beck, P. G.; Houmani, K.; Salabert, D. [Laboratoire AIM, CEA/DRF-CNRS-Université Paris Diderot, IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Huber, D.; Stello, D. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Regulo, C. [Universidad de La Laguna, Dpto de Astrofísica, E-38206, Tenerife (Spain)

    2016-08-10

    Asteroseismology has proven to be an excellent tool to determine not only global stellar properties with good precision, but also to infer the stellar structure, dynamics, and evolution for a large sample of Kepler stars. Prior to the launch of the mission, the properties of Kepler targets were inferred from broadband photometry, leading to the Kepler Input Catalog (KIC). The KIC was later revised in the Kepler Star Properties Catalog, based on literature values and an asteroseismic analysis of stars that were unclassified in the KIC. Here, we present an asteroseismic analysis of 45,400 stars that were classified as dwarfs in the Kepler Star Properties Catalog. We found that around 2% of the sample shows acoustic modes in the typical frequency range that put them in the red-giant category rather than the cool dwarf category. We analyze the asteroseismic properties of these stars, derive their surface gravities, masses, and radii, and present updated effective temperatures and distances. We show that the sample is significantly fainter than the previously known oscillating giants in the Kepler field, with the faintest stars reaching down to a Kepler magnitude of Kp ∼ 16. We demonstrate that 404 stars are at distances beyond 5 kpc and that the stars are significantly less massive than for the original Kepler red-giant sample, consistent with a population of distant halo giants. A comparison with a galactic population model shows that up to 40 stars might be genuine halo giants, which would increase the number of known asteroseismic halo stars by a factor of 4. The detections presented here will provide a valuable sample for galactic archeology studies.

  18. High-resolution abundance analysis of red giants in the globular cluster NGC 6522

    Science.gov (United States)

    Barbuy, B.; Chiappini, C.; Cantelli, E.; Depagne, E.; Pignatari, M.; Hirschi, R.; Cescutti, G.; Ortolani, S.; Hill, V.; Zoccali, M.; Minniti, D.; Trevisan, M.; Bica, E.; Gómez, A.

    2014-10-01

    Context. The [Sr/Ba] and [Y/Ba] scatter observed in some galactic halo stars that are very metal-poor and in a few individual stars of the oldest known Milky Way globular cluster NGC 6522 have been interpreted as evidence of early enrichment by massive fast-rotating stars (spinstars). Because NGC 6522 is a bulge globular cluster, the suggestion was that not only the very-metal poor halo stars, but also bulge stars at [Fe/H] ~ -1 could be used as probes of the stellar nucleosynthesis signatures from the earlier generations of massive stars, but at much higher metallicity. For the bulge the suggestions were based on early spectra available for stars in NGC 6522, with a medium resolution of R ~ 22 000 and a moderate signal-to-noise ratio. Aims: The main purpose of this study is to re-analyse the NGC 6522 stars reported previously by using new high-resolution (R ~ 45 000) and high signal-to-noise spectra (S/N > 100). We aim at re-deriving their stellar parameters and elemental ratios, in particular the abundances of the neutron-capture s-process-dominated elements such as Sr, Y, Zr, La, and Ba, and of the r-element Eu. Methods: High-resolution spectra of four giants belonging to the bulge globular cluster NGC 6522 were obtained at the 8m VLT UT2-Kueyen telescope with the UVES spectrograph in FLAMES-UVES configuration. The spectroscopic parameters were derived based on the excitation and ionization equilibrium of Fe i and Fe ii. Results: Our analysis confirms a metallicity [Fe/H] = -0.95 ± 0.15 for NGC 6522 and the overabundance of the studied stars in Eu (with +0.2 < [Eu/Fe] < + 0.4) and alpha-elements O and Mg. The neutron-capture s-element-dominated Sr, Y, Zr, Ba, and La now show less pronounced variations from star to star. Enhancements are in the range 0.0 < [Sr/Fe] < +0.4, +0.23 < [Y/Fe] < +0.43, 0.0 < [Zr/Fe] < +0.4, 0.0 < [La/Fe] < +0.35, and 0.05 < [Ba/Fe] < +0.55. Conclusions: The very high overabundances of [Y/Fe] previously reported for the four studied

  19. Giant Magnetoresistance in Carbon Nanotubes with Single-Molecule Magnets TbPc2.

    Science.gov (United States)

    Krainov, Igor V; Klier, Janina; Dmitriev, Alexander P; Klyatskaya, Svetlana; Ruben, Mario; Wernsdorfer, Wolfgang; Gornyi, Igor V

    2017-07-25

    We present experimental results and a theoretical model for the gate-controlled spin-valve effect in carbon nanotubes with side-attached single-molecule magnets TbPc 2 (Terbium(III) bis-phthalocyanine). These structures show a giant magnetoresistance up to 1000% in experiments on single-wall nanotubes that are tunnel-coupled to the leads. The proposed theoretical model combines the spin-dependent Fano effect with Coulomb blockade and predicts a spin-spin interaction between the TbPc 2 molecules, mediated by conducting electrons via the charging effect. This gate-tuned interaction is responsible for the stable magnetic ordering of the inner spins of the molecules in the absence of magnetic field. In the case of antiferromagnetic arrangement, electrons with either spin experience the scattering by the molecules, which results in blocking the linear transport. In strong magnetic fields, the Zeeman energy exceeds the effective antiferromagnetic coupling and one species of electrons is not scattered by molecules, which leads to a much lower total resistance at the resonant values of gate voltage, and hence to a supramolecular spin-valve effect.

  20. On the cosmic ray spectrum from type II Supernovae expanding in their red giant presupernova wind

    Science.gov (United States)

    Cardillo, Martina

    2015-12-01

    While from the energetic point of view SNRs are viable sources of Galactic CRs, the issue of whether they can accelerate protons up to PeV remains unsolved. Here we discuss particle acceleration at the forward shock of SN and discuss the possibility that the escaping particle current may excite a non-resonant instability that in turn leads to the formation of resonant modes confining particles close to the shock and increasing the maximum energy. This mechanism works throughout the expansion of the SN explosion, from the ejecta dominated (ED) to the Sedov-Taylor (ST) phase. Because of their higher explosion rate,we focus on type II SNae expanding in the slow, dense red supergiant wind. When the explosion occurs in such winds, the transition between the ED and the ST phase is likely to take place within a few tens of years. As a result, the spectrum of accelerated particles shows a break in the slope, at the maximum energy (EM) achieved at the beginning of the ST phase. Above this energy, the spectrum becomes steeper but remains a power law than developing an exponential cutoff. We show that for type II SNae typical parameters, proton EM can easily reach PeV energies, confirming that type II SNRs are the best candidate sources for CRs at the knee. We have tried to fit KASCADE-Grande, ARGO -YBJ and YAC1-Tibet Array data with our model but we could not find any parameter combination that could explain all data sets. Indeed the recent measurement of the proton and helium spectra in the knee region, with the ARGO-YBJ and YAC1-Tibet Array, has made the situation very confused. These measurements suggest that the knee in the light component is at 650 TeV, appreciably below the overall spectrum knee. This finding would resolve the problem of reaching very high energies in SNae, but, on the other hand, it would open a critical issue in the transition region between Galactic and extragalactic CRs.

  1. CA II TRIPLET SPECTROSCOPY OF SMALL MAGELLANIC CLOUD RED GIANTS. III. ABUNDANCES AND VELOCITIES FOR A SAMPLE OF 14 CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Parisi, M. C.; Clariá, J. J.; Marcionni, N. [Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, Córdoba, CP 5000 (Argentina); Geisler, D.; Villanova, S. [Departamento de Astronomía, Universidad de Concepción Casilla 160-C, Concepción (Chile); Sarajedini, A. [Department of Astronomy, University of Florida P.O. Box 112055, Gainesville, FL 32611 (United States); Grocholski, A. J., E-mail: celeste@oac.uncor.edu, E-mail: claria@oac.uncor.edu, E-mail: nmarcionni@oac.uncor.edu, E-mail: dgeisler@astro-udec.cl, E-mail: svillanova@astro-udec.cl, E-mail: ata@astro.ufl.edu, E-mail: grocholski@phys.lsu.edu [Department of Physics and Astronomy, Louisiana State University 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States)

    2015-05-15

    We obtained spectra of red giants in 15 Small Magellanic Cloud (SMC) clusters in the region of the Ca ii lines with FORS2 on the Very Large Telescope. We determined the mean metallicity and radial velocity with mean errors of 0.05 dex and 2.6 km s{sup −1}, respectively, from a mean of 6.5 members per cluster. One cluster (B113) was too young for a reliable metallicity determination and was excluded from the sample. We combined the sample studied here with 15 clusters previously studied by us using the same technique, and with 7 clusters whose metallicities determined by other authors are on a scale similar to ours. This compilation of 36 clusters is the largest SMC cluster sample currently available with accurate and homogeneously determined metallicities. We found a high probability that the metallicity distribution is bimodal, with potential peaks at −1.1 and −0.8 dex. Our data show no strong evidence of a metallicity gradient in the SMC clusters, somewhat at odds with recent evidence from Ca ii triplet spectra of a large sample of field stars. This may be revealing possible differences in the chemical history of clusters and field stars. Our clusters show a significant dispersion of metallicities, whatever age is considered, which could be reflecting the lack of a unique age–metallicity relation in this galaxy. None of the chemical evolution models currently available in the literature satisfactorily represents the global chemical enrichment processes of SMC clusters.

  2. Constraining stellar physics from red-giant stars in binaries – stellar rotation, mixing processes and stellar activity

    Directory of Open Access Journals (Sweden)

    Beck P. G.

    2017-01-01

    Full Text Available The unparalleled photometric data obtained by NASA’s Kepler Space Telescope has led to an improved understanding of stellar structure and evolution - in particular for solar-like oscillators in this context. Binary stars are fascinating objects. Because they were formed together, binary systems provide a set of two stars with very well constrained parameters. Those can be used to study properties and physical processes, such as the stellar rotation, dynamics and rotational mixing of elements and allows us to learn from the differences we find between the two components. In this work, we discussed a detailed study of the binary system KIC 9163796, discovered through Kepler photometry. The ground-based follow-up spectroscopy showed that this system is a double-lined spectroscopic binary, with a mass ratio close to unity. However, the fundamental parameters of the components of this system as well as their lithium abundances differ substantially. Kepler photometry of this system allows to perform a detailed seismic analysis as well as to derive the orbital period and the surface rotation rate of the primary component of the system. Indications of the seismic signature of the secondary are found. The differing parameters are best explained with both components located in the early and the late phase of the first dredge up at the bottom of the red-giant branch. Observed lithium abundances in both components are in good agreement with prediction of stellar models including rotational mixing. By combining observations and theory, a comprehensive picture of the system can be drawn.

  3. Phylogenetic Diversity, Distribution, and Cophylogeny of Giant Bacteria (Epulopiscium) with their Surgeonfish Hosts in the Red Sea

    Science.gov (United States)

    Miyake, Sou; Ngugi, David K.; Stingl, Ulrich

    2016-01-01

    Epulopiscium is a group of giant bacteria found in high abundance in intestinal tracts of herbivorous surgeonfish. Despite their peculiarly large cell size (can be up to 600 μm), extreme polyploidy (some with over 100,000 genome copies per cell) and viviparity (whereby mother cells produce live offspring), details about their diversity, distribution or their role in the host gut are lacking. Previous studies have highlighted the existence of morphologically distinct Epulopiscium cell types (defined as morphotypes A to J) in some surgeonfish genera, but the corresponding genetic diversity and distribution among other surgeonfishes remain mostly unknown. Therefore, we investigated the phylogenetic diversity of Epulopiscium, distribution and co-occurrence in multiple hosts. Here, we identified eleven new phylogenetic clades, six of which were also morphologically characterized. Three of these novel clades were phylogenetically and morphologically similar to cigar-shaped type A1 cells, found in a wide range of surgeonfishes including Acanthurus nigrofuscus, while three were similar to smaller, rod-shaped type E that has not been phylogenetically classified thus far. Our results also confirmed that biogeography appears to have relatively little influence on Epulopiscium diversity, as clades found in the Great Barrier Reef and Hawaii were also recovered from the Red Sea. Although multiple symbiont clades inhabited a given species of host surgeonfish and multiple host species possessed a given symbiont clade, statistical analysis of host and symbiont phylogenies indicated significant cophylogeny, which in turn suggests co-evolutionary relationships. A cluster analysis of Epulopiscium sequences from previously published amplicon sequencing dataset revealed a similar pattern, where specific clades were consistently found in high abundance amongst closely related surgeonfishes. Differences in abundance may indicate specialization of clades to certain gut environments

  4. Phylogenetic Diversity, Distribution, and Cophylogeny of Giant Bacteria (Epulopiscium) with their Surgeonfish Hosts in the Red Sea

    KAUST Repository

    Miyake, Sou

    2016-03-14

    Epulopiscium is a group of giant bacteria found in high abundance in intestinal tracts of herbivorous surgeonfish. Despite their peculiarly large cell size (can be up to 600 μm), extreme polyploidy (some with over 100,000 genome copies per cell) and viviparity (whereby mother cells produce live offspring), details about their diversity, distribution or their role in the host gut are lacking. Previous studies have highlighted the existence of morphologically distinct Epulopiscium cell types (defined as morphotypes A to J) in some surgeonfish genera, but the corresponding genetic diversity and distribution among other surgeonfishes remain mostly unknown. Therefore, we investigated the phylogenetic diversity of Epulopiscium, distribution and co-occurrence in multiple hosts. Here, we identified eleven new phylogenetic clades, six of which were also morphologically characterized. Three of these novel clades were phylogenetically and morphologically similar to cigar-shaped type A1 cells, found in a wide range of surgeonfishes including Acanthurus nigrofuscus, while three were similar to smaller, rod-shaped type E that has not been phylogenetically classified thus far. Our results also confirmed that biogeography appears to have relatively little influence on Epulopiscium diversity, as clades found in the Great Barrier Reef and Hawaii were also recovered from the Red Sea. Although multiple symbiont clades inhabited a given species of host surgeonfish and multiple host species possessed a given symbiont clade, statistical analysis of host and symbiont phylogenies indicated significant cophylogeny, which in turn suggests co-evolutionary relationships. A cluster analysis of Epulopiscium sequences from previously published amplicon sequencing dataset revealed a similar pattern, where specific clades were consistently found in high abundance amongst closely related surgeonfishes. Differences in abundance may indicate specialization of clades to certain gut environments

  5. Phylogenetic Diversity, Distribution, and Cophylogeny of Giant Bacteria (Epulopiscium) with their Surgeonfish Hosts in the Red Sea

    KAUST Repository

    Miyake, Sou; Ngugi, David; Stingl, Ulrich

    2016-01-01

    Epulopiscium is a group of giant bacteria found in high abundance in intestinal tracts of herbivorous surgeonfish. Despite their peculiarly large cell size (can be up to 600 μm), extreme polyploidy (some with over 100,000 genome copies per cell) and viviparity (whereby mother cells produce live offspring), details about their diversity, distribution or their role in the host gut are lacking. Previous studies have highlighted the existence of morphologically distinct Epulopiscium cell types (defined as morphotypes A to J) in some surgeonfish genera, but the corresponding genetic diversity and distribution among other surgeonfishes remain mostly unknown. Therefore, we investigated the phylogenetic diversity of Epulopiscium, distribution and co-occurrence in multiple hosts. Here, we identified eleven new phylogenetic clades, six of which were also morphologically characterized. Three of these novel clades were phylogenetically and morphologically similar to cigar-shaped type A1 cells, found in a wide range of surgeonfishes including Acanthurus nigrofuscus, while three were similar to smaller, rod-shaped type E that has not been phylogenetically classified thus far. Our results also confirmed that biogeography appears to have relatively little influence on Epulopiscium diversity, as clades found in the Great Barrier Reef and Hawaii were also recovered from the Red Sea. Although multiple symbiont clades inhabited a given species of host surgeonfish and multiple host species possessed a given symbiont clade, statistical analysis of host and symbiont phylogenies indicated significant cophylogeny, which in turn suggests co-evolutionary relationships. A cluster analysis of Epulopiscium sequences from previously published amplicon sequencing dataset revealed a similar pattern, where specific clades were consistently found in high abundance amongst closely related surgeonfishes. Differences in abundance may indicate specialization of clades to certain gut environments

  6. Antimicrobial Peptide Lactoferricin B-Induced Rapid Leakage of Internal Contents from Single Giant Unilamellar Vesicles.

    Science.gov (United States)

    Moniruzzaman, Md; Alam, Jahangir Md; Dohra, Hideo; Yamazaki, Masahito

    2015-09-29

    Enzymatic digestion of bovine lactoferrin generates lactoferricin B (Lfcin B), a 25-mer peptide with strong antimicrobial activity of unknown mechanism. To elucidate the mechanistic basis of Lfcin B bactericidal activity, we investigated the interaction of Lfcin B with Escherichia coli and liposomes of lipid membranes. Lfcin B induced the influx of a membrane-impermeant fluorescent probe, SYTOX green, from the outside of E. coli into its cytoplasm. Lfcin B induced gradual leakage of calcein from large unilamellar vesicles (LUVs) of dioleoylphosphatidylglycerol (DOPG)/dioleoylphosphatidylcholine (DOPC) membranes. To clarify the cause of Lfcin B-induced leakage of calcein from the LUVs, we used the single giant unilamellar vesicle (GUV) method to investigate the interaction of Lfcin B with calcein-containing DOPG/DOPC-GUVs. We observed that a rapid leakage of calcein from a GUV started stochastically; statistical analysis provided a rate constant for Lfcin B-induced pore formation, kp. On the other hand, phase-contrast microscopic images revealed that Lfcin B induced a rapid leakage of sucrose from the single GUVs with concomitant appearance of a spherical GUV of smaller diameter. Because of the very fast leakage, and at the present time resolution of the experiments (33 ms), we could not follow the evolution of pore nor the process of the structural changes of the GUV. Here we used the term "local rupture" to express the rapid leakage of sucrose and determined the rate constant of local rupture, kL. On the basis of the comparison between kp and kL, we concluded that the leakage of calcein from single GUVs occurred as a result of a local rupture in the GUVs and that smaller pores inducing leakage of calcein were not formed before the local rupture. The results of the effect of the surface charge density of lipid membranes and that of salt concentration in buffer on kp clearly show that kp increases with an increase in the extent of electrostatic interactions due to

  7. Asteroseismology of old open clusters with Kepler: direct estimate of the integrated red giant branch mass-loss in NGC 6791 and 6819

    DEFF Research Database (Denmark)

    Miglio, A.; Brogaard, Karsten Frank; Stello, D.

    2012-01-01

    Mass-loss of red giant branch (RGB) stars is still poorly determined, despite its crucial role in the chemical enrichment of galaxies. Thanks to the recent detection of solar-like oscillations in G–K giants in open clusters with Kepler, we can now directly determine stellar masses...... for a statistically significant sample of stars in the old open clusters NGC 6791 and 6819. The aim of this work is to constrain the integrated RGB mass-loss by comparing the average mass of stars in the red clump (RC) with that of stars in the low-luminosity portion of the RGB [i.e. stars with L≲L(RC)]. Stellar...... masses were determined by combining the available seismic parameters νmax and Δν with additional photometric constraints and with independent distance estimates. We measured the masses of 40 stars on the RGB and 19 in the RC of the old metal-rich cluster NGC 6791. We find that the difference between...

  8. Stellar Evolution in NGC 6791: Mass Loss on the Red Giant Branch and the Formation of Low-Mass White Dwarfs

    Science.gov (United States)

    Kalirai, Jasonjot S.; Bergeron, P.; Hansen, Brad M. S.; Kelson, Daniel D.; Reitzel, David B.; Rich, R. Michael; Richer, Harvey B.

    2007-12-01

    We present the first detailed study of the properties (temperatures, gravities, and masses) of the NGC 6791 white dwarf population. This unique stellar system is both one of the oldest (8 Gyr) and most metal-rich ([Fe/H]~+0.4) open clusters in our Galaxy and has a color-magnitude diagram (CMD) that exhibits both a red giant clump and a much hotter extreme horizontal branch. Fitting the Balmer lines of the white dwarfs in the cluster using Keck/LRIS spectra suggests that most of these stars are undermassive, =0.43+/-0.06 Msolar, and therefore could not have formed from canonical stellar evolution involving the helium flash at the tip of the red giant branch. We show that at least 40% of NGC 6791's evolved stars must have lost enough mass on the red giant branch to avoid the flash and therefore did not convert helium into carbon-oxygen in their core. Such increased mass loss in the evolution of the progenitors of these stars is consistent with the presence of the extreme horizontal branch in the CMD. This unique stellar evolutionary channel also naturally explains the recent finding of a very young age (2.4 Gyr) for NGC 6791 from white dwarf cooling theory; helium-core white dwarfs in this cluster will cool ~3 times slower than carbon-oxygen-core stars, and therefore the corrected white dwarf cooling age is in fact >~7 Gyr, consistent with the well-measured main-sequence turnoff age. These results provide direct empirical evidence that mass loss is much more efficient in high-metallicity environments and therefore may be critical in interpreting the ultraviolet upturn in elliptical galaxies. Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Based on observations obtained at the

  9. Giant magnetoimpedance effect in sputtered single layered NiFe film and meander NiFe/Cu/NiFe film

    International Nuclear Information System (INIS)

    Chen, L.; Zhou, Y.; Lei, C.; Zhou, Z.M.; Ding, W.

    2010-01-01

    Giant magnetoimpedance (GMI) effect on NiFe thin film is very promising due to its application in developing the magnetic field sensors with highly sensitivity and low cost. In this paper, the single layered NiFe thin film and NiFe/Cu/NiFe thin film with a meander structure are prepared by the MEMS technology. The influences of sputtering parameters, film structure and conductor layer width on GMI effect in NiFe single layer and meander NiFe/Cu/NiFe film are investigated. Maximum of the GMI ratio in single layer and sandwich film is 5% and 64%, respectively. The results obtained are useful for developing the high-performance magnetic sensors based on NiFe thin film.

  10. Single-walled carbon nanotubes as stabilizing agents in red phosphorus Li-ion battery anodes

    KAUST Repository

    Smajic, Jasmin

    2017-08-16

    Phosphorus boasts extremely high gravimetric and volumetric capacities but suffers from poor electrochemical stability with significant capacity loss immediately after the first cycle. We propose to circumvent this issue by mixing amorphous red phosphorus with single-walled carbon nanotubes. Employing a non-destructive sublimation–deposition method, we have synthesized composites where the synergetic effect between red phosphorus and single-walled carbon nanotubes allows for a considerable improvement in the electrochemical stability of battery anodes. In contrast to the average 40% loss of capacity after 50 cycles for other phosphorus–carbon composites in the literature, our material shows losses of just 22% under analogous cycling conditions.

  11. Toward long-term all-sky time domain surveys-SINDICS: a prospective concept for a Seismic INDICes Survey of half a million red giants

    Directory of Open Access Journals (Sweden)

    Michel Eric

    2015-01-01

    Full Text Available CoRoT and Kepler have brought a new and deep experience in long-term photometric surveys and how to use them. This is true for exoplanets characterizing, stellar seismology and beyond for studying several other phenomena, like granulation or activity. Based on this experience, it has been possible to propose new generation projects, like TESS and PLATO, with more specific scientific objectives and more ambitious observational programs in terms of sky coverage and/or duration of the observations. In this context and as a prospective exercise, we explore here the possibility to set up an all-sky survey optimized for seismic indices measurement, providing masses, radii and evolution stages for half a million solar-type pulsators (subgiants and red giants, in our galactic neighborhood and allowing unprecedented stellar population studies.

  12. Destruction of /sup 18/O in red giants. A search for a sub-threshold resonance in the /sup 18/O+p system

    Energy Technology Data Exchange (ETDEWEB)

    Champagne, A E; Pitt, M L

    1986-09-08

    The /sup 18/O(/sup 3/He,d)/sup 19/F reaction has been used to determine if a presumed sub-threshold resonance at Esub(c.m.)=-94 KeV in the /sup 18/O(p,..cap alpha..)/sup 15/N reaction exists at an astrophysically significant level. No evidence for this state was observed which implies a dimensionless reduced width thetasub(p)/sup 2/<5 . 10/sup -5/. In addition, a proton width GAMMAsub(p)=2 x 10/sup -19/ eV has been determined for a d-wave resonance located at Esub(c.m.)=20 keV. The resulting thermonuclear reaction rate is slow enough to ensure that /sup 18/O is not destroyed at red-giant temperatures.

  13. Giant volume magnetostriction in the Y{sub 2}Fe{sub 17} single crystal at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, S. A., E-mail: nikitin@phys.msu.ru; Pankratov, N. Yu.; Smarzhevskaya, A. I.; Politova, G. A. [Physics Faculty, Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Pastushenkov, Yu. G., E-mail: yupast@mail.ru; Skokov, K. P. [Physics Faculty, Tver State University, 170100 Tver (Russian Federation); Moral, A. del [Laboratorio de Magnetismo de Slidos, Departamento de Fisica de Materia Condensada and Instituto de Ciencia de Materiales de Aragn, Facultad de Ciencias, Universidad de Zaragoza-C.S.I.C, E-50009 Zaragoza (Spain)

    2015-05-21

    An investigation of the Y{sub 2}Fe{sub 17} compound belonging to the class of intermetallic alloys of rare-earth and 3d-transition metals is presented. The magnetization, magnetostriction, and thermal expansion of the Y{sub 2}Fe{sub 17} single crystal were studied. The forced magnetostriction and magnetostriction constants were investigated in the temperature range of the magnetic ordering close to the room temperature. The giant field induced volume magnetostriction was discovered in the room temperature region in the magnetic field up to 1.2 T. The contributions of both anisotropic single-ion and isotropic pair exchange interactions to the volume magnetostriction and magnetostriction constants were determined. The experimental results were interpreted within the framework of the Standard Theory of Magnetostriction and the Landau thermodynamic theory. It was found out that the giant values of the volume magnetostriction were caused by the strong dependence of the 3d-electron Coulomb charge repulsion on the deformations and width of the 3d-electron energy band.

  14. Single-dish and VLBI observations of Cygnus X-3 during the 2016 giant flare episode

    Science.gov (United States)

    Egron, E.; Pellizzoni, A.; Giroletti, M.; Righini, S.; Stagni, M.; Orlati, A.; Migoni, C.; Melis, A.; Concu, R.; Barbas, L.; Buttaccio, S.; Cassaro, P.; De Vicente, P.; Gawroński, M. P.; Lindqvist, M.; Maccaferri, G.; Stanghellini, C.; Wolak, P.; Yang, J.; Navarrini, A.; Loru, S.; Pilia, M.; Bachetti, M.; Iacolina, M. N.; Buttu, M.; Corbel, S.; Rodriguez, J.; Markoff, S.; Wilms, J.; Pottschmidt, K.; Cadolle Bel, M.; Kalemci, E.; Belloni, T.; Grinberg, V.; Marongiu, M.; Vargiu, G. P.; Trois, A.

    2017-11-01

    In 2016 September, the microquasar Cygnus X-3 underwent a giant radio flare, which was monitored for 6 d with the Medicina Radio Astronomical Station and the Sardinia Radio Telescope. Long observations were performed in order to follow the evolution of the flare on an hourly scale, covering six frequency ranges from 1.5 to 25.6 GHz. The radio emission reached a maximum of 13.2 ± 0.7 Jy at 7.2 GHz and 10 ± 1 Jy at 18.6 GHz. Rapid flux variations were observed at high radio frequencies at the peak of the flare, together with rapid evolution of the spectral index: α steepened from 0.3 to 0.6 (with Sν ∝ ν-α) within 5 h. This is the first time that such fast variations are observed, giving support to the evolution from optically thick to optically thin plasmons in expansion moving outward from the core. Based on the Italian network (Noto, Medicina and SRT) and extended to the European antennas (Torun, Yebes, Onsala), very long baseline interferometry (VLBI) observations were triggered at 22 GHz on five different occasions, four times prior to the giant flare, and once during its decay phase. Flux variations of 2 h duration were recorded during the first session. They correspond to a mini-flare that occurred close to the core 10 d before the onset of the giant flare. From the latest VLBI observation we infer that 4 d after the flare peak the jet emission was extended over 30 mas.

  15. The UK Infrared Telescope M33 monitoring project - I. Variable red giant stars in the central square kiloparsec

    Science.gov (United States)

    Javadi, Atefeh; van Loon, Jacco Th.; Mirtorabi, Mohammad Taghi

    2011-02-01

    We have conducted a near-infrared monitoring campaign at the UK Infrared Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. The most extensive data set was obtained in the K band with the UIST instrument for the central 4 × 4 arcmin2 (1 kpc2) - this contains the nuclear star cluster and inner disc. These data, taken during the period 2003-2007, were complemented by J- and H-band images. Photometry was obtained for 18 398 stars in this region; of these, 812 stars were found to be variable, most of which are asymptotic giant branch (AGB) stars. Our data were matched to optical catalogues of variable stars and carbon stars and to mid-infrared photometry from the Spitzer Space Telescope. In this first of a series of papers, we present the methodology of the variability survey and the photometric catalogue - which is made publicly available at the Centre de Données astronomiques de Strasbourg - and discuss the properties of the variable stars. The most dusty AGB stars had not been previously identified in optical variability surveys, and our survey is also more complete for these types of stars than the Spitzer survey.

  16. Single frequency Nd:YLF and Nd:YVO4 laser in the red emission

    International Nuclear Information System (INIS)

    Camargo, Fabiola de Almeida

    2010-01-01

    All solid-state continuous-wave (cw) narrow emission linewidth and tunable red lasers are convenient alternative sources to bulky and expensive dye-lasers for high precision laser spectroscopy. Single-frequency operation of diode-pumped Nd:YLiF 4 and Nd:YVO 4 cw ring lasers were investigated in the 1.32 - 1.34μm range, together with their intracavity second-harmonic generation (SHG) to the red spectral range (0.65 - 0.67μm) using either BiB 3 O 6 (BiBO) or periodically-poled KTiOPO 4 (ppKTP) crystals. We report on such a single-end diode-pumped Nd:YVO 4 unidirectional red ring laser containing a type-I cut BiBO nonlinear crystal, yielding a record of 680 mW of single-longitudinal mode (SLM) red output power at 671.1nm without any intra-cavity etalon. For smooth SLM wavelength tuning over the full gain bandwidth (∼4 nm), a partially-coated (R = 40%) 100μm-thin etalon was found necessary, reducing the maximum SLM power (at 671.15 nm) to 380 mW. At 1342.5nm and with a T = 2% transmission output coupler, the laser provided an optimal 1.5W of single-frequency power. We demonstrate also optimal intracavity SHG of a Nd:YLF ring laser in the π- polarization (λ = 1321.5nm) using a ppKTP. The laser yielded 1.4 W of single frequency red power at 660.5 nm, as much as the maximum fundamental power that can be extracted from the resonator using an optimal output coupler. With a partially coated (R = 25%) thin etalon, the laser was tunable over Δλ∼ 1.6nm. (author)

  17. A single population of red globular clusters around the massive compact galaxy NGC 1277

    Science.gov (United States)

    Beasley, Michael A.; Trujillo, Ignacio; Leaman, Ryan; Montes, Mireia

    2018-03-01

    Massive galaxies are thought to form in two phases: an initial collapse of gas and giant burst of central star formation, followed by the later accretion of material that builds up their stellar and dark-matter haloes. The systems of globular clusters within such galaxies are believed to form in a similar manner. The initial central burst forms metal-rich (spectrally red) clusters, whereas more metal-poor (spectrally blue) clusters are brought in by the later accretion of less-massive satellites. This formation process is thought to result in the multimodal optical colour distributions that are seen in the globular cluster systems of massive galaxies. Here we report optical observations of the massive relic-galaxy candidate NGC 1277—a nearby, un-evolved example of a high-redshift ‘red nugget’ galaxy. We find that the optical colour distribution of the cluster system of NGC 1277 is unimodal and entirely red. This finding is in strong contrast to other galaxies of similar and larger stellar mass, the cluster systems of which always exhibit (and are generally dominated by) blue clusters. We argue that the colour distribution of the cluster system of NGC 1277 indicates that the galaxy has undergone little (if any) mass accretion after its initial collapse, and use simulations of possible merger histories to show that the stellar mass due to accretion is probably at most ten per cent of the total stellar mass of the galaxy. These results confirm that NGC 1277 is a genuine relic galaxy and demonstrate that blue clusters constitute an accreted population in present-day massive galaxies.

  18. New Records Reveal the Actual Distribution of Cratomelus meritus Gorochov (Orthoptera: Anostostomatidae), a Giant Red Cricket from Chile.

    Science.gov (United States)

    Alfaro, F M; Zuñiga-Reinoso, A; Muñoz-Ramírez, C; Elgueta, M

    2015-04-01

    The geographic distribution of the red cricket Cratomelus meritus Gorochov had remained unknown until now due to mislabeling and lack of new records. The aim of this short communication is to uncover and establish the actual distribution of the species on the basis of new records and discuss potential biogeographic hypotheses about its distribution.

  19. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions

    International Nuclear Information System (INIS)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C

    2007-01-01

    Se have investigated single and double ionization of C 60 molecule in collisions with 2.33 MeV/u Si q+ (q=6-14) and 3.125 MeV/u O q+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C 60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening

  20. DETAILED ABUNDANCES OF RED GIANTS IN THE GLOBULAR CLUSTER NGC 1851: C+N+O AND THE ORIGIN OF MULTIPLE POPULATIONS

    International Nuclear Information System (INIS)

    Villanova, S.; Geisler, D.; Piotto, G.

    2010-01-01

    We present chemical abundance analysis of a sample of 15 red giant branch (RGB) stars of the globular cluster NGC 1851 distributed along the two RGBs of the (v, v-y) color-magnitude diagram. We determined abundances for C+N+O, Na, α, iron-peak, and s-elements. We found that the two RGB populations significantly differ in their light (N, O, Na) and s-element content. On the other hand, they do not show any significant difference in their α and iron-peak element content. More importantly, the two RGB populations do not show any significant difference in their total C+N+O content. Our results do not support previous hypotheses suggesting that the origins of the two RGBs and the two subgiant branches of the cluster are related to different content of either α (including Ca) or iron-peak elements, or C+N+O abundance, due to a second generation polluted by Type II supernovae.

  1. Room-temperature superparamagnetism due to giant magnetic anisotropy in Mo S defected single-layer MoS2

    Science.gov (United States)

    Khan, M. A.; Leuenberger, Michael N.

    2018-04-01

    Room-temperature superparamagnetism due to a large magnetic anisotropy energy (MAE) of a single atom magnet has always been a prerequisite for nanoscale magnetic devices. Realization of two dimensional (2D) materials such as single-layer (SL) MoS2, has provided new platforms for exploring magnetic effects, which is important for both fundamental research and for industrial applications. Here, we use density functional theory (DFT) to show that the antisite defect (Mo S ) in SL MoS2 is magnetic in nature with a magnetic moment μ of  ∼2 μB and, remarkably, exhibits an exceptionally large atomic scale MAE =\\varepsilon\\parallel-\\varepsilon\\perp of  ∼500 meV. Our calculations reveal that this giant anisotropy is the joint effect of strong crystal field and significant spin–orbit coupling (SOC). In addition, the magnetic moment μ can be tuned between 1 μB and 3 μB by varying the Fermi energy \\varepsilonF , which can be achieved either by changing the gate voltage or by chemical doping. We also show that MAE can be raised to  ∼1 eV with n-type doping of the MoS2:Mo S sample. Our systematic investigations deepen our understanding of spin-related phenomena in SL MoS2 and could provide a route to nanoscale spintronic devices.

  2. METALLICITIES, AGE-METALLICITY RELATIONSHIPS, AND KINEMATICS OF RED GIANT BRANCH STARS IN THE OUTER DISK OF THE LARGE MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Carrera, R.; Gallart, C.; Aparicio, A.; Hardy, E.

    2011-01-01

    The outer disk of the Large Magellanic Cloud (LMC) is studied in order to unveil clues about its formation and evolution. Complementing our previous studies in innermost fields (3 kpc ∼< R ∼< 7 kpc), we obtained deep color-magnitude diagrams in six fields with galactocentric distances from 5.2 kpc to 9.2 kpc and different azimuths. The comparison with isochrones shows that while the oldest population is approximately coeval in all fields, the age of the youngest populations increases with increasing radius. This agrees with the results obtained in the innermost fields. Low-resolution spectroscopy in the infrared Ca II triplet region has been obtained for about 150 stars near the tip of the red giant branch in the same fields. Radial velocities and stellar metallicities have been obtained from these spectra. The metallicity distribution of each field has been analyzed together with those previously studied. The metal content of the most metal-poor objects, which are also the oldest according to the derived age-metallicity relationships, is similar in all fields independently of the galactocentric distance. However, while the metallicity of the most metal-rich objects measured, which are the youngest ones, remains constant in the inner 6 kpc, it decreases with increasing radius from there on. The same is true for the mean metallicity. According to the derived age-metallicity relationships, which are consistent with being the same in all fields, this result may be interpreted as an outside-in formation scheme in opposition with the inside-out scenario predicted by ΛCDM cosmology for a galaxy like the LMC. The analysis of the radial velocities of our sample of giants shows that they follow a rotational cold disk kinematics. The velocity dispersion increases as metallicity decreases indicating that the most metal-poor/oldest objects are distributed in a thicker disk than the most metal-rich/youngest ones in agreement with the findings in other disks such as that of

  3. Efficient frequency downconversion at the single photon level from the red spectral range to the telecommunications C-band.

    Science.gov (United States)

    Zaske, Sebastian; Lenhard, Andreas; Becher, Christoph

    2011-06-20

    We report on single photon frequency downconversion from the red part of the spectrum (738 nm) to the telecommunications C-band. By mixing attenuated laser pulses with an average photon number per pulse telecommunications wavelengths.

  4. Raman tweezers spectroscopy of live, single red and white blood cells.

    Directory of Open Access Journals (Sweden)

    Aseefhali Bankapur

    Full Text Available An optical trap has been combined with a Raman spectrometer to make high-resolution measurements of Raman spectra of optically-immobilized, single, live red (RBC and white blood cells (WBC under physiological conditions. Tightly-focused, near infrared wavelength light (1064 nm is utilized for trapping of single cells and 785 nm light is used for Raman excitation at low levels of incident power (few mW. Raman spectra of RBC recorded using this high-sensitivity, dual-wavelength apparatus has enabled identification of several additional lines; the hitherto-unreported lines originate purely from hemoglobin molecules. Raman spectra of single granulocytes and lymphocytes are interpreted on the basis of standard protein and nucleic acid vibrational spectroscopy data. The richness of the measured spectrum illustrates that Raman studies of live cells in suspension are more informative than conventional micro-Raman studies where the cells are chemically bound to a glass cover slip.

  5. ASEAN SINGLE AVIATION MARKET AND INDONESIA - WILL IT SURVIVE AGAINST THE GIANTS?

    Directory of Open Access Journals (Sweden)

    Ruwantissa Indranath Abeyratne

    2014-11-01

    Full Text Available  To say that Indonesia is an enigma in air transport is an understatement.  On the one hand,  the  demand for air transport in Indonesia is higher in proportion to its GDP per capita.  Its economy can be expected to grow 6% to 10% annually. A single aviation market could add another 6% to 10% growth in sheer demand.  It is one of the wealthiest countries in the world, being the 16th richest country currently, and, according to an Airbus forecast,   will be the 7th richest in 2030.  Yet its airports are badly in need of expansion, its infrastructure is bursting at its seems, and above all, its airlines are strongly resisting liberalization of air transport in the region for fear of being wiped out by stronger contenders in the region.  Against this backdrop, it is incontrovertible that Indonesia's civil aviation is intrinsically linked to regional and global considerations.  Indonesia's archipelagic topography makes its people heavily reliant on safe, regular and reliable air services that may connect them not only internally but also to the outside world.A single aviation market in the ASEAN region will bring both benefits to Indonesia and challengers to its air transport sector. This article discusses the economic and regulatory challenges that Indonesia faces with the coming into effect of the ASEAN Single Aviation market in 2015.

  6. Comparison of Magnetization Tunneling in the Giant-Spin and Multi-Spin Descriptions of Single-Molecule Magnets

    Science.gov (United States)

    Liu, Junjie; Del Barco, Enrique; Hill, Stephen

    2010-03-01

    We perform a mapping of the spectrum obtained for a triangular Mn3 single-molecule magnet (SMM) with idealized C3 symmetry via exact diagonalization of a multi-spin (MS) Hamiltonian onto that of a giant-spin (GS) model which assumes strong ferromagnetic coupling and a spin S = 6 ground state. Magnetic hysteresis measurements on this Mn3 SMM reveal clear evidence that the steps in magnetization due to magnetization tunneling obey the expected quantum mechanical selection rules [J. Henderson et al., Phys. Rev. Lett. 103, 017202 (2009)]. High-frequency EPR and magnetization data are first fit to the MS model. The tunnel splittings obtained via the two models are then compared in order to find a relationship between the sixth order transverse anisotropy term B6^6 in GS model and the exchange constant J coupling the Mn^III ions in the MS model. We also find that the fourth order transverse term B4^3 in the GS model is related to the orientation of JahnTeller axes of Mn^III ions, as well as J

  7. Chemical Abundances of Main-sequence, Turnoff, Subgiant, and Red Giant Stars from APOGEE Spectra. I. Signatures of Diffusion in the Open Cluster M67

    Science.gov (United States)

    Souto, Diogo; Cunha, Katia; Smith, Verne V.; Allende Prieto, C.; García-Hernández, D. A.; Pinsonneault, Marc; Holzer, Parker; Frinchaboy, Peter; Holtzman, Jon; Johnson, J. A.; Jönsson, Henrik; Majewski, Steven R.; Shetrone, Matthew; Sobeck, Jennifer; Stringfellow, Guy; Teske, Johanna; Zamora, Olga; Zasowski, Gail; Carrera, Ricardo; Stassun, Keivan; Fernandez-Trincado, J. G.; Villanova, Sandro; Minniti, Dante; Santana, Felipe

    2018-04-01

    Detailed chemical abundance distributions for 14 elements are derived for eight high-probability stellar members of the solar metallicity old open cluster M67 with an age of ∼4 Gyr. The eight stars consist of four pairs, with each pair occupying a distinct phase of stellar evolution: two G dwarfs, two turnoff stars, two G subgiants, and two red clump (RC) K giants. The abundance analysis uses near-IR high-resolution spectra (λ1.5–1.7 μm) from the Apache Point Observatory Galactic Evolution Experiment survey and derives abundances for C, N, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe. Our derived stellar parameters and metallicity for 2M08510076+1153115 suggest that this star is a solar twin, exhibiting abundance differences relative to the Sun of ≤0.04 dex for all elements. Chemical homogeneity is found within each class of stars (∼0.02 dex), while significant abundance variations (∼0.05–0.20 dex) are found across the different evolutionary phases; the turnoff stars typically have the lowest abundances, while the RCs tend to have the largest. Non-LTE corrections to the LTE-derived abundances are unlikely to explain the differences. A detailed comparison of the derived Fe, Mg, Si, and Ca abundances with recently published surface abundances from stellar models that include chemical diffusion provides a good match between the observed and predicted abundances as a function of stellar mass. Such agreement would indicate the detection of chemical diffusion processes in the stellar members of M67.

  8. Engineering giant magnetic anisotropy in single-molecule magnets by dimerizing heavy transition-metal atoms

    Science.gov (United States)

    Qu, Jiaxing; Hu, Jun

    2018-05-01

    The search for single-molecule magnets with large magnetic anisotropy energy (MAE) is essential for the development of molecular spintronics devices for use at room temperature. Through systematic first-principles calculations, we found that an Os–Os or Ir–Ir dimer embedded in the (5,5‧-Br2-salophen) molecule gives rise to a large MAE of 41.6 or 51.4 meV, respectively, which is large enough to hold the spin orientation at room temperature. Analysis of the electronic structures reveals that the top Os and Ir atoms play the most important part in the total spin moments and large MAEs of the molecules.

  9. Measurement of the viability of stored red cells by the single-isotope technique using 51Cr. Analysis of validity

    International Nuclear Information System (INIS)

    Beutler, E.; West, C.

    1984-01-01

    A single-isotope 51 Cr method often is used to evaluate the viability of stored red cells. In this technique, the red cell mass is measured by back-extrapolation to time zero (t0) of the radioactivity of the blood between 5 and 20 minutes after infusion of the sample. If there is early destruction of stored cells, this method provides an overestimate of the red cell mass and, hence, of the viability of the stored cells. Freshly drawn red cells from normal donors were labeled with /sup 99m/Tc, and cells from the same donor which had been stored in citrate-phosphate-dextrose-adenine-one (CPDA-1) for periods ranging from 7 to 49 days were labeled with 51 Cr. A comparison of the ''true red cell mass'' as determined with /sup 99m/Tc with the back-extrapolated red cell mass from stored 51 Cr-labeled cells has made it possible to define the magnitude of error introduced by early loss of red cells. The overestimation of red cell mass and viability was diminished if only the 51 Cr radioactivity between 5 and 15 minutes after infusion was used in back-extrapolating to t0. The degree of overestimation of red cell mass was greatest when the red cell viability had declined to very low levels. However, in the entire range of 10 to 80 percent viability, the overestimate of viability was usually less than 4 percent. The overestimate of viability proved to be quite similar for all samples and may be taken into account when using the single-isotope technique for measurement of red cell viability

  10. Development of a red TL detection system for a single grain of quartz

    International Nuclear Information System (INIS)

    Yawata, T.; Hashimoto, T.

    2007-01-01

    Red thermoluminescence (RTL) of natural quartz grains offers many desirable properties for quaternary chronology and archaeological dating, although RTL measurements suffer from high thermal background due to black-body radiation on heating. To reduce the thermal background to as low a level as possible, a silver sample disc covered with a biotite plate with a sample hole was used in combination with a light guide, cluster heater, optical filters, and photomultiplier tube cooling to -20 deg. C in the present system. As a result, the thermal background decreased from 2x10 4 to 1000 cps in the temperature range 350-380 deg. C, resulting in a detection limit of approximately 100 cps, corresponding to the RTL signal from a single quartz grain (250-500μm) irradiated with 4.0 Gy. In addition, application of lower heating rates retarded the thermal quenching effect, resulting in high RTL signals, which are preferable for young or insensitive quartz samples. Using RTL measurements with the single quartz grain method under optimal RTL conditions, comparison of equivalent doses from artificially irradiated single quartz grains to the known dose was within the 20% measurement error. Based on equivalent dose determinations for single quartz grains, large irregularities on non-etched quartz surfaces might be very detrimental to the TL detection process. This result confirms that surface etching treatment is required to achieve reliable dating with high counting efficiency

  11. The Carnegie-Chicago Hubble Program. II. The Distance to IC 1613: The Tip of the Red Giant Branch and RR Lyrae Period-luminosity Relations

    Science.gov (United States)

    Hatt, Dylan; Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Jang, In-Sung; Hoyt, Taylor J.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark

    2017-08-01

    IC 1613 is an isolated dwarf galaxy within the Local Group. Low foreground and internal extinction, low metallicity, and low crowding make it an invaluable testbed for the calibration of the local distance ladder. We present new, high-fidelity distance estimates to IC 1613 via its Tip of the Red Giant Branch (TRGB) and its RR Lyrae (RRL) variables as part of the Carnegie-Chicago Hubble Program, which seeks an alternate local route to H 0 using Population II stars. We have measured a TRGB magnitude {I}{ACS}{TRGB}=20.35+/- {0.01}{stat}+/- {0.01}{sys} mag using wide-field observations obtained from the IMACS camera on the Magellan-Baade telescope. We have further constructed optical and near-infrared RRL light curves using archival BI- and new H-band observations from the ACS/WFC and WFC3/IR instruments on board the Hubble Space Telescope (HST). In advance of future Gaia data releases, we set provisional values for the TRGB luminosity via the Large Magellanic Cloud and Galactic RRL zero-points via HST parallaxes. We find corresponding true distance moduli {μ }0{TRGB}=24.30+/- {0.03}{stat}+/- {0.05}{sys} {mag} and =24.28+/- {0.04}{stat+{sys}} mag. We compare our results to a body of recent publications on IC 1613 and find no statistically significant difference between the distances derived from Population I and II stars. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #10505 and #13691. Additional observations are credited to the Observatories of the Carnegie Institution of Washington for the use of Magellan-Baade IMACS. Presented as part of a dissertation to the Department of Astronomy and Astrophysics, The University of Chicago, in partial fulfillment of the requirements for the Ph.D. degree.

  12. Giant grains

    International Nuclear Information System (INIS)

    Leitch-Devlin, M.A.; Millar, T.J.; Williams, D.A.

    1976-01-01

    Infrared observations of the Orion nebula have been interpreted by Rowan-Robinson (1975) to imply the existence of 'giant' grains, radius approximately 10 -2 cm, throughout a volume about a parsec in diameter. Although Rowan-Robinson's model of the nebula has been criticized and the presence of such grains in Orion is disputed, the proposition is accepted, that they exist, and in this paper situations in which giant grains could arise are examined. It is found that, while a giant-grain component to the interstellar grain density may exist, it is difficult to understand how giant grains arise to the extent apparently required by the Orion nebula model. (Auth.)

  13. Red-IR stimulated luminescence in K-feldspar: Single or multiple trap origin?

    DEFF Research Database (Denmark)

    Andersen, Martin Thalbitzer; Jain, Mayank; Tidemand-Lichtenberg, Peter

    2012-01-01

    We investigate on the origins of the infra-red stimulated luminescence (IRSL) signals in 3 potassium feldspars based on IR-red spectroscopy (700–1050 nm) using a fiber-coupled tunable Ti:Sapphire laser, in combination with different thermal and optical (pre)treatments of the samples. We also...

  14. Storage characteristics of multiple-donor pooled red blood cells compared to single-donor red blood cell units.

    Science.gov (United States)

    Mathur, Aabhas; Chowdhury, Raquibul; Hillyer, Christopher D; Mitchell, W Beau; Shaz, Beth H

    2016-12-01

    Each unit of blood donated is processed and stored individually resulting in variability in the amount of red blood cells (RBCs) collected, RBC properties, and the 24-hour posttransfusion RBC survivability. As a result, each unit differs in its ability to deliver oxygen and potentially its effects on the recipient. The goal of this study was to investigate the storage of pooled RBCs from multiple donors in comparison to control standard RBC units. Two units of irradiated, leukoreduced RBCs of same ABO, D, E, C, and K antigen phenotype were collected from each of five donors using apheresis. One unit from each donor was pooled in a 2-L bag and remaining units were used as controls. After being pooled, RBCs were separated in five bags and stored at 4°C along with the controls. Quality indexes were measured on Days 2, 14, and 28 for all the units. Adenosine triphosphate assays for both pooled and controls showed a slight decrease from Day 2 to Day 28 (pooled/control from 5.22/5.24 to 4.35/4.33 µmol/g hemoglobin [Hb]). 2,3-Diphosphoglycerate was successfully rejuvenated for all RBC units on Day 28 (pooled 11.46 µmol/g Hb; control 11.86 µmol/g Hb). The results showed a nonsignificant difference between pooled and control units, with a general trend of lower standard deviation for pooled units when compared to controls. Pooled units have reduced unit-to-unit variability. Future exploration of their immunogenicity is required before using pooled units for transfusion. © 2016 AABB.

  15. Red Sirius

    Energy Technology Data Exchange (ETDEWEB)

    Martynov, D Ya

    1976-01-01

    A hypothesis is proposed explaining the assumption that Sirius changed its colour from red in the second century to pale blue in the tenth century A.D. The hypothesis is based on the possibility of transformation of a Sirius satellite (Sirius B) from a red giant in the past to a white dwarf in the present. Such a transformation would have been accompanied by an explosion of Sirius B, which is clearly visible from the Earth. The fact that the increase in Sirius brightness by 4-5 units is not reflected in historical chronicles is attributed to the degradation of sciences in Europe in 4-10 centuries.

  16. Perception of color emotions for single colors in red-green defective observers.

    Science.gov (United States)

    Sato, Keiko; Inoue, Takaaki

    2016-01-01

    It is estimated that inherited red-green color deficiency, which involves both the protan and deutan deficiency types, is common in men. For red-green defective observers, some reddish colors appear desaturated and brownish, unlike those seen by normal observers. Despite its prevalence, few studies have investigated the effects that red-green color deficiency has on the psychological properties of colors (color emotions). The current study investigated the influence of red-green color deficiency on the following six color emotions: cleanliness, freshness, hardness, preference, warmth, and weight. Specifically, this study aimed to: (1) reveal differences between normal and red-green defective observers in rating patterns of six color emotions; (2) examine differences in color emotions related to the three cardinal channels in human color vision; and (3) explore relationships between color emotions and color naming behavior. Thirteen men and 10 women with normal vision and 13 men who were red-green defective performed both a color naming task and an emotion rating task with 32 colors from the Berkeley Color Project (BCP). Results revealed noticeable differences in the cleanliness and hardness ratings between the normal vision observers, particularly in women, and red-green defective observers, which appeared mainly for colors in the orange to cyan range, and in the preference and warmth ratings for colors with cyan and purple hues. Similarly, naming errors also mainly occurred in the cyan colors. A regression analysis that included the three cone-contrasts (i.e., red-green, blue-yellow, and luminance) as predictors significantly accounted for variability in color emotion ratings for the red-green defective observers as much as the normal individuals. Expressly, for warmth ratings, the weight of the red-green opponent channel was significantly lower in color defective observers than in normal participants. In addition, the analyses for individual warmth ratings in

  17. Perception of color emotions for single colors in red-green defective observers

    Directory of Open Access Journals (Sweden)

    Keiko Sato

    2016-12-01

    Full Text Available It is estimated that inherited red-green color deficiency, which involves both the protan and deutan deficiency types, is common in men. For red-green defective observers, some reddish colors appear desaturated and brownish, unlike those seen by normal observers. Despite its prevalence, few studies have investigated the effects that red-green color deficiency has on the psychological properties of colors (color emotions. The current study investigated the influence of red-green color deficiency on the following six color emotions: cleanliness, freshness, hardness, preference, warmth, and weight. Specifically, this study aimed to: (1 reveal differences between normal and red-green defective observers in rating patterns of six color emotions; (2 examine differences in color emotions related to the three cardinal channels in human color vision; and (3 explore relationships between color emotions and color naming behavior. Thirteen men and 10 women with normal vision and 13 men who were red-green defective performed both a color naming task and an emotion rating task with 32 colors from the Berkeley Color Project (BCP. Results revealed noticeable differences in the cleanliness and hardness ratings between the normal vision observers, particularly in women, and red-green defective observers, which appeared mainly for colors in the orange to cyan range, and in the preference and warmth ratings for colors with cyan and purple hues. Similarly, naming errors also mainly occurred in the cyan colors. A regression analysis that included the three cone-contrasts (i.e., red-green, blue-yellow, and luminance as predictors significantly accounted for variability in color emotion ratings for the red-green defective observers as much as the normal individuals. Expressly, for warmth ratings, the weight of the red-green opponent channel was significantly lower in color defective observers than in normal participants. In addition, the analyses for individual warmth

  18. Optical tweezers for measuring the interaction of the two single red blood cells in flow condition

    Science.gov (United States)

    Lee, Kisung; Muravyov, Alexei; Semenov, Alexei; Wagner, Christian; Priezzhev, Alexander

    2017-03-01

    Aggregation of red blood cells (RBCs) is an intrinsic property of blood, which has direct effect on the blood viscosity and therefore affects overall the blood circulation throughout the body. It is attracting interest for the research in both fundamental science and clinical application. Despite of the intensive research, the aggregation mechanism is remaining not fully clear. Recent advances in methods allowed measuring the interaction between single RBCs in a well-defined configuration leading the better understanding of the mechanism of the process. However the most of the studies were made on the static cells. Thus, the measurements in flow mimicking conditions are missing. In this work, we aim to study the interaction of two RBCs in the flow conditions. We demonstrate the characterization of the cells interaction strength (or flow tolerance) by measuring the flow velocity to be applied to separate two aggregated cells trapped by double channel optical tweezers in a desired configuration. The age-separated cells were used for this study. The obtained values for the minimum flow velocities needed to separate the two cells were found to be 78.9 +/- 6.1 μm/s and 110 +/- 13 μm/s for old and young cells respectively. The data obtained is in agreement with the observations reported by other authors. The significance of our results is in ability for obtaining a comprehensible and absolute physical value characterizing the cells interaction in flow conditions (not like the Aggregation Index measured in whole blood suspensions by other techniques, which is some abstract parameter)

  19. Juvenile giant fibroadenoma

    Directory of Open Access Journals (Sweden)

    Vipul Yagnik

    2011-07-01

    Full Text Available Fibroadenomas are benign solid tumor associated with aberration of normal lobular development. Juvenile giant fibroadenoma is usually single and >5 cm in size /or >500 gms in weight. Important differential diagnoses are: phyllodes tumor and juvenile gigantomastia. Simple excision is the treatment of choice.

  20. Giant plasmon excitation in single and double ionization of C{sub 60} by fast highly charged Si and O ions

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai-5 (India)

    2007-09-15

    Se have investigated single and double ionization of C{sub 60} molecule in collisions with 2.33 MeV/u Si{sup q+} (q=6-14) and 3.125 MeV/u O{sup q+} (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C{sub 60} are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.

  1. Percutaneous nephroscopic management of an isolated giant renal hydatid cyst guided by single-incision laparoscopy using conventional instruments: the Santosh-PGI technique.

    Science.gov (United States)

    Kumar, Santosh; Choudhary, Gautam R; Pushkarna, Arawat; Najjapa, Bhuvnesh; Ht, Vatasla

    2013-11-01

    Isolated renal hydatid rarely presents, but when it does occur, it requires surgical treatment. We report our experience with a novel technique involving percutaneous management of a giant renal hydatid cyst with single-incision laparoscopic assistance. First we performed retrograde ureteropyelogram, which did not show any communication between the cyst and the calyceal. A Veress needle was used for pneumoperitoneum. Three conventional laparoscopic trocars used. Under laparoscopic guidance, we punctured the cyst. The scolicidal solution used was 10% povidone-iodine. The endocyst was removed under vision with grasping forceps through the nephroscope. A Portex drain was placed into the cyst cavity. Percutaneous aspiration and instillation of scolicidal agents followed by re-aspiration have been previously reported. This is an attractive procedure because of its acceptable success rates and reduced morbidity. In our case, simple aspiration of the cyst would not have been successful because the cyst was full of daughter cysts. Also, a blind percutaneous puncture of the cyst and dilatation could have perforated the colon or the mesocolon, which is often wrapped over the surface of such giant cysts thereby making laparoscopic guidance and mobilization of the colon imperative. We devised this unique treatment method for this patient involving three conventional ports at a single umbilical site. We believe this is the first reported case of its kind in the world. Not only this technique is minimally invasive, it is also cost-effective, as only conventional laparoscopic ports and instruments are used during the procedure. © 2013 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.

  2. Allium discoloration: the precursor and formation of the red pigment in giant onion (Allium giganteum Regel) and some other subgenus Melanocrommyum species

    Czech Academy of Sciences Publication Activity Database

    Kučerová, P.; Kubec, R.; Šimek, Petr; Václavík, P.; Schraml, Jan

    2011-01-01

    Roč. 59, č. 5 (2011), s. 1821-1828 ISSN 0021-8561 R&D Projects: GA AV ČR IAA400720706 Grant - others:Grantová agentura Jihočeské univerzity(CZ) 067/2010/7 Institutional research plan: CEZ:AV0Z50070508; CEZ:AV0Z40720504 Keywords : S-(2-pyrrolyl)cysteine S-oxide * S-(3-pyrrolyl)cysteine S-oxide * giant onion Subject RIV: CE - Biochemistry Impact factor: 2.823, year: 2011

  3. A TALE OF DWARFS AND GIANTS: USING A z = 1.62 CLUSTER TO UNDERSTAND HOW THE RED SEQUENCE GREW OVER THE LAST 9.5 BILLION YEARS

    International Nuclear Information System (INIS)

    Rudnick, Gregory H.; Tran, Kim-Vy; Papovich, Casey; Momcheva, Ivelina; Willmer, Christopher

    2012-01-01

    We study the red sequence in a cluster of galaxies at z = 1.62 and follow its evolution over the intervening 9.5 Gyr to the present day. Using deep YJK s imaging with the HAWK-I instrument on the Very Large Telescope, we identify a tight red sequence and construct its rest-frame i-band luminosity function (LF). There is a marked deficit of faint red galaxies in the cluster that causes a turnover in the LF. We compare the red-sequence LF to that for clusters at z 0.6. In this model the cluster accretes blue galaxies from the field whose star formation is quenched and who are subsequently allowed to merge. We find that three to four mergers among cluster galaxies during the 4 Gyr between z = 1.62 and z = 0.6 match the observed LF evolution between the two redshifts. The inferred merger rate is consistent with other studies of this cluster. Our result supports the picture that galaxy merging during the major growth phase of massive clusters is an important process in shaping the red-sequence population at all luminosities.

  4. Does red noise increase or decrease extinction risk? Single extreme events versus series of unfavorable conditions.

    Science.gov (United States)

    Schwager, Monika; Johst, Karin; Jeltsch, Florian

    2006-06-01

    Recent theoretical studies have shown contrasting effects of temporal correlation of environmental fluctuations (red noise) on the risk of population extinction. It is still debated whether and under which conditions red noise increases or decreases extinction risk compared with uncorrelated (white) noise. Here, we explain the opposing effects by introducing two features of red noise time series. On the one hand, positive autocorrelation increases the probability of series of poor environmental conditions, implying increasing extinction risk. On the other hand, for a given time period, the probability of at least one extremely bad year ("catastrophe") is reduced compared with white noise, implying decreasing extinction risk. Which of these two features determines extinction risk depends on the strength of environmental fluctuations and the sensitivity of population dynamics to these fluctuations. If extreme (catastrophic) events can occur (strong noise) or sensitivity is high (overcompensatory density dependence), then temporal correlation decreases extinction risk; otherwise, it increases it. Thus, our results provide a simple explanation for the contrasting previous findings and are a crucial step toward a general understanding of the effect of noise color on extinction risk.

  5. Red flags in children with chronic abdominal pain and Crohn's disease-a single center experience.

    Science.gov (United States)

    El-Chammas, Khalil; Majeskie, Angela; Simpson, Pippa; Sood, Manu; Miranda, Adrian

    2013-04-01

    To compare history and symptoms at initial presentation of patients with chronic abdominal pain (CAP) and Crohn's disease (CD). Red flags are used to help determine which patients with CAP are likely to have an underlying disease such as CD. However, red flags have not been validated and pediatric studies are lacking. Patients seen in the outpatient Pediatric Gastroenterology Clinic at Children's Hospital of Wisconsin between 2005 and 2008 prospectively completed a demographic, history, and symptom questionnaire. Patients with abdominal pain for at least 1 month and no evidence of organic disease were compared with patients diagnosed with CD confirmed by mucosal biopsies. Data were collected on 606 patients (128 with CD and 478 with functional gastrointestinal disorders). Patients with functional gastrointestinal disorders had more stressors (P pain were no different between groups. Anemia, hematochezia, and weight loss were most predictive of CD (cumulative sensitivity of 94%). The presence of anemia, hematochezia, and weight loss help identify patients with CAP who require further work-up and referral to a pediatric gastroenterologist. Furthermore, waking from sleep or joint pain occurred similarly between groups and should not be considered as "red flags." Copyright © 2013. Published by Mosby, Inc.

  6. Giant Chancroid

    Directory of Open Access Journals (Sweden)

    Bhushan Kumar

    1980-01-01

    Full Text Available A case of giant chancroid following rupture of inguinal bubo and having systemic symptoms is described. Response with sulfa and streptomycin combination was excellent and the lesion healed completely in 3 weeks. Early diagnosis and treatment of chancroid will prevent this debilitating complication.

  7. Giant microelectronics

    International Nuclear Information System (INIS)

    Della Sala, D.; Privato, C.; Di Lazzaro, P.; Fortunato, G.

    1999-01-01

    Giant microelectronics, on which the technology of flat liquid-crystal screens is based, is an example of fruitful interaction among independently-developed technologies, in this case thin film micro devices and laser applications. It typifies the interdisciplinary approach needed to produce innovations in microelectronics [it

  8. Studies on the structure and function of intestinal microbes of surgeonfishes in the central Red Sea with a focus on the giant bacteria Epulopiscium spp.

    KAUST Repository

    Miyake, Sou

    2015-05-01

    The intestinal tract microbiota – microbial community of the gut – is an important field in microbiology not only because of its critical role in the host development, but also increasingly large number of diseases are associated with certain state of the gut microbiota. The community structure and function of the gut microbiota is relatively well studied in humans and related higher vertebrates, but is severely understudied in fish. This is especially true for the coral reef fishes, who constitute the most diverse assemblage of vertebrates spread over a very local scale, and are essential for the resilience of the reefs. In order to bridge this gap in knowledge, this dissertation studied the community structure, interactions and functions of the gut microbial community from the surgeonfishes in the Red Sea – with special focus on the surgeonfish enteric symbiont Epulopiscium spp. Initially, I studied the composition of the gut microbiota of nine surgeonfish and three nonsurgeonfish species from the Red Sea using 454 pyrosequencing. Upon discovering the high abundance of Epulopiscium spp. in herbivorous surgeonfishes, I then proceeded to identify their phylogenetic diversity, distribution, as well as deducing their coevolutionary relationship with the host. Because Epulopiscium spp. undergo substantial changes in the cell size (grow up to ~600μm) and the DNA concentration (from 85 to over 250pg per cell) throughout their diel lifecycle, I also studied the temporal changes in their expression pattern using RNA-seq. Overall, this dissertation shed light on the complex structure, interaction and function of an important family of coral reef fish from the Red Sea through range of molecular techniques.

  9. AGB [asymptotic giant branch]: Star evolution

    International Nuclear Information System (INIS)

    Becker, S.A.

    1987-01-01

    Asymptotic giant branch stars are red supergiant stars of low-to-intermediate mass. This class of stars is of particular interest because many of these stars can have nuclear processed material brought up repeatedly from the deep interior to the surface where it can be observed. A review of recent theoretical and observational work on stars undergoing the asymptotic giant branch phase is presented. 41 refs

  10. Red Clump stars in Kepler open cluster NGC 6819

    Directory of Open Access Journals (Sweden)

    Abedigamba O.P.

    2015-01-01

    Full Text Available We measure the large frequency separation, Δν, and the frequency of maximum amplitude, νmax, for 10 Red Clump (RC single member (SM stars in the Kepler open cluster NGC 6819. We derive luminosities and masses for each individual RC star. A comparison of the observations with an isochrone of Age = 2.5 Gyr, Z = 0.017 with no mass loss using a statistical techniques is made. A fractional mass loss of 5 ± 3 percent is obtained if we assume that no correction to Δν between RC and red-giant branch (RGB is necessary. However, models suggest that an effective correction of about 1.9 percent in Δν is required to obtain the correct mass of RC stars owing to the different internal structures of stars in the two evolutionary stages. In this case we find that the mass loss in the red giant branch is not significantly different from zero. This finding confirms that of [6]. It is clear that the mass estimate obtained by asteroseismology is not sufficient to deduce the mass loss on the red giant branch. However, it is clearly only a few percent at most.

  11. Probing the Deep End of the Milky Way with New Oscillating Kepler Giants

    Science.gov (United States)

    Mathur, Savita; García, Rafael A.; Huber, Daniel; Regulo, Clara; Stello, Dennis; Beck, Paul G.; Houmani, Kenza; Salabert, David

    2017-10-01

    The Kepler mission has been a success in both exoplanet search and stellar physics studies. Red giants have actually been quite a highlight in the Kepler scene. The Kepler long and almost continuous four-year observations allowed us to detect oscillations in more than 15,000 red giants targeted by the mission. However by looking at the power spectra of 45,000 stars classified as dwarfs according to the Q1-16 Kepler star properties catalog, we detected red-giant like oscillations in 850 stars. Even though this is a small addition to the known red-giant sample, these misclassified stars represent a goldmine for galactic archeology studies. Indeed they happen to be fainter (down to Kp 16) and more distant (d>10kPc) than the known red giants, opening the possibility to probe unknown regions of our Galaxy. The faintness of these red giants with detected oscillations is very promising for detecting acoustic modes in red giants observed with K2 and TESS. In this talk, I will present this new sample of red giants with their revised stellar parameters derived from asteroseismology. Then I will discuss about the distribution of their masses, distances, and evolutionary states compared to the previously known sample of red giants.

  12. Theoretical model for optical oximetry at the capillary level: exploring hemoglobin oxygen saturation through backscattering of single red blood cells

    Science.gov (United States)

    Liu, Rongrong; Spicer, Graham; Chen, Siyu; Zhang, Hao F.; Yi, Ji; Backman, Vadim

    2017-02-01

    Oxygen saturation (sO2) of red blood cells (RBCs) in capillaries can indirectly assess local tissue oxygenation and metabolic function. For example, the altered retinal oxygenation in diabetic retinopathy and local hypoxia during tumor development in cancer are reflected by abnormal sO2 of local capillary networks. However, it is far from clear whether accurate label-free optical oximetry (i.e., measuring hemoglobin sO2) is feasible from dispersed RBCs at the single capillary level. The sO2-dependent hemoglobin absorption contrast present in optical scattering signal is complicated by geometry-dependent scattering from RBCs. We present a numerical study of backscattering spectra from single RBCs based on the first-order Born approximation, considering practical factors: RBC orientations, size variation, and deformations. We show that the oscillatory spectral behavior of RBC geometries is smoothed by variations in cell size and orientation, resulting in clear sO2-dependent spectral contrast. In addition, this spectral contrast persists with different mean cellular hemoglobin content and different deformations of RBCs. This study shows for the first time the feasibility of, and provides a theoretical model for, label-free optical oximetry at the single capillary level using backscattering-based imaging modalities, challenging the popular view that such measurements are impossible at the single capillary level.

  13. Gamma graphic findings in giant hepatic hemangioma

    International Nuclear Information System (INIS)

    Cano, R.; Morales, R.; Mendoza, P.; Ramirez, E.; Aguilar, C.

    1994-01-01

    The aim of the present work is to describe gamma graphic findings in patients with giant hepatic hemangiomas, when evaluated with 99m Tc red blood cell (RBC) imaging. Three patients with clinical suspicion of giant hepatic hemangiomas, who had had, ultrasound and computed tomography were studied with RBC using in vivo labelling with pyrophosphate. All cases had dynamic and static views. All cases showed hypoperfusion in dynamics views and over perfusion in delayed studies. Surgery confirmed diagnosis in two cases. 99m Tc RBC is a good method for diagnosis of giant hepatic hemangioma, which generally needs surgical treatment. (Authors). 24 refs., 2 figs

  14. Light emission ranging from blue to red from a series of Iguana/GaN single quantum wells

    International Nuclear Information System (INIS)

    Martin, R.W.; Edwards, P.R.; Pecharroman-Gallego, R.; O'Donnell, K.P.; Liu, C.; Deatcher, C.J.; Watson, I.M.

    2002-01-01

    In this paper, we describe the growth and characterization of InGaN single quantum wells with emission peaks in the blue, green, amber and red spectral regions, grown by metal-organic vapour phase epitaxy. Starting from the growth of a blue-emitting (peak ∼430 nm) InGaN quantum well at 860 deg. C the InGaN growth temperature was progressively reduced. The photoluminescence peak wavelength, measured at low temperature, shifts through the green and orange spectral regions and reaches 670 nm for an InGaN growth temperature of 760 deg. C. This corresponds to an energy lower than the currently accepted band-gap of the binary compound, InN. Spectral characteristics of the luminescence peaks will be discussed, including an analysis of the phonon-assisted contribution. Low energy secondary ion mass spectrometry analysis provides information on the indium content and thickness of the 'blue' and 'red' quantum wells. The results are combined to discuss the origin of the 'sub-band-gap' luminescence in terms of the combined influence of InN-GaN segregation and the effect of intense piezoelectric fields. (author)

  15. Light emission ranging from blue to red from a series of Iguana/GaN single quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.W. [Department of Physics, University of Strathclyde, Glasgow (United Kingdom)]. E-mail: r.w.martin@strath.ac.uk; Edwards, P.R.; Pecharroman-Gallego, R.; O' Donnell, K.P. [Department of Physics, University of Strathclyde, Glasgow (United Kingdom); Liu, C.; Deatcher, C.J.; Watson, I.M. [Institute of Photonics, University of Strathclyde, Glasgow (United Kingdom)

    2002-04-07

    In this paper, we describe the growth and characterization of InGaN single quantum wells with emission peaks in the blue, green, amber and red spectral regions, grown by metal-organic vapour phase epitaxy. Starting from the growth of a blue-emitting (peak {approx}430 nm) InGaN quantum well at 860 deg. C the InGaN growth temperature was progressively reduced. The photoluminescence peak wavelength, measured at low temperature, shifts through the green and orange spectral regions and reaches 670 nm for an InGaN growth temperature of 760 deg. C. This corresponds to an energy lower than the currently accepted band-gap of the binary compound, InN. Spectral characteristics of the luminescence peaks will be discussed, including an analysis of the phonon-assisted contribution. Low energy secondary ion mass spectrometry analysis provides information on the indium content and thickness of the 'blue' and 'red' quantum wells. The results are combined to discuss the origin of the 'sub-band-gap' luminescence in terms of the combined influence of InN-GaN segregation and the effect of intense piezoelectric fields. (author)

  16. Raman spectroscopic monitoring of the bioeffects of nitroglycerin on Hb-O II in single red blood cell

    Science.gov (United States)

    Chiang, Huihua Kenny; Ruan, Hung-Shiang; Cheng, Hung-You; Fang, Tung-Ting

    2007-02-01

    Raman spectroscopy has been shown to have the potential for providing oxygenated ability of erythrocytes. Raman line at 1638 cm-1 has also been reported as one significant oxygenic indicator for erythrocytes. In this research, we develop the Raman spectroscopic monitoring of the bioeffects of Nitroglycerin on hemoglobin oxygen saturation in a single red blood cell (RBC). Nitroglycerin has been frequently used in the management of angina pectoris. Nitroglycerin liberates nitric oxide (NO) to blood vessels. NO is an oxidizer that easily converts hemoglobin to methemoglobin. The conversion may cause the decrease of oxygenated ability of erythrocytes. In this study, we observed the oxidize state of erythrocytes caused by the over dosage of Nitroglycerin. When the dose of Nitroglycerin exceeds 2x10 -4 M, the oxygenic state of erythrocytes decreases significantly. The Raman spectroscopic results demonstrate the observation of the bioeffects of Nitroglycerin on hemoglobin.

  17. Giant crystal-electric-field effect and complex magnetic behavior in single-crystalline CeRh3Si2

    Science.gov (United States)

    Pikul, A. P.; Kaczorowski, D.; Gajek, Z.; Stȩpień-Damm, J.; Ślebarski, A.; Werwiński, M.; Szajek, A.

    2010-05-01

    Single-crystalline CeRh3Si2 was investigated by means of x-ray diffraction, magnetic susceptibility, magnetization, electrical resistivity, and specific-heat measurements carried out in wide temperature and magnetic field ranges. Moreover, the electronic structure of the compound was studied at room temperature by cerium core-level x-ray photoemission spectroscopy (XPS). The physical properties were analyzed in terms of crystalline electric field and compared with results of ab initio band-structure calculations performed within the density-functional theory approach. The compound was found to crystallize in the orthorhombic unit cell of the ErRh3Si2 type (space group Imma No.74, Pearson symbol: oI24 ) with the lattice parameters a=7.1330(14)Å , b=9.7340(19)Å , and c=5.6040(11)Å . Analysis of the magnetic and XPS data revealed the presence of well-localized magnetic moments of trivalent cerium ions. All the physical properties were found to be highly anisotropic over the whole temperature range studied and influenced by exceptionally strong crystalline electric field with the overall splitting of the 4f1 ground multiplet exceeding 5700 K. Antiferromagnetic order of the cerium magnetic moments at TN=4.70(1)K and their subsequent spin rearrangement at Tt=4.48(1)K manifest themselves as distinct anomalies in the temperature characteristic of all the physical properties investigated and exhibit complex evolution in an external magnetic field. A tentative magnetic B-T phase diagram, constructed for B parallel to the b axis being the easy magnetization direction, shows very complex magnetic behavior of CeRh3Si2 , similar to that recently reported for an isostructural compound CeIr3Si2 . The electronic band-structure calculations corroborated the antiferromagnetic ordering of the cerium magnetic moments and well-reproduced the experimental XPS valence-band spectrum.

  18. A single enhancer regulating the differential expression of duplicated red-sensitive opsin genes in zebrafish.

    Directory of Open Access Journals (Sweden)

    Taro Tsujimura

    2010-12-01

    Full Text Available A fundamental step in the evolution of the visual system is the gene duplication of visual opsins and differentiation between the duplicates in absorption spectra and expression pattern in the retina. However, our understanding of the mechanism of expression differentiation is far behind that of spectral tuning of opsins. Zebrafish (Danio rerio have two red-sensitive cone opsin genes, LWS-1 and LWS-2. These genes are arrayed in a tail-to-head manner, in this order, and are both expressed in the long member of double cones (LDCs in the retina. Expression of the longer-wave sensitive LWS-1 occurs later in development and is thus confined to the peripheral, especially ventral-nasal region of the adult retina, whereas expression of LWS-2 occurs earlier and is confined to the central region of the adult retina, shifted slightly to the dorsal-temporal region. In this study, we employed a transgenic reporter assay using fluorescent proteins and P1-artificial chromosome (PAC clones encompassing the two genes and identified a 0.6-kb "LWS-activating region" (LAR upstream of LWS-1, which regulates expression of both genes. Under the 2.6-kb flanking upstream region containing the LAR, the expression pattern of LWS-1 was recapitulated by the fluorescent reporter. On the other hand, when LAR was directly conjugated to the LWS-2 upstream region, the reporter was expressed in the LDCs but also across the entire outer nuclear layer. Deletion of LAR from the PAC clones drastically lowered the reporter expression of the two genes. These results suggest that LAR regulates both LWS-1 and LWS-2 by enhancing their expression and that interaction of LAR with the promoters is competitive between the two genes in a developmentally restricted manner. Sharing a regulatory region between duplicated genes could be a general way to facilitate the expression differentiation in duplicated visual opsins.

  19. Chemical Analysis of Asymptotic Giant Branch Stars in M62

    NARCIS (Netherlands)

    Lapenna, E.; Mucciarelli, A.; Ferraro, F. R.; Origlia, L.; Lanzoni, B.; Massari, D.; Dalessandro, E.

    2015-01-01

    We have collected UVES-FLAMES high-resolution spectra for a sample of 6 asymptotic giant branch (AGB) and 13 red giant branch (RGB) stars in the Galactic globular cluster (GC) M62 (NGC 6266). Here we present the detailed abundance analysis of iron, titanium, and light elements (O, Na, Mg, and Al).

  20. Complete Resolution of a Giant Pigment Epithelial Detachment Secondary to Exudative Age-Related Macular Degeneration after a Single Intravitreal Ranibizumab (Lucentis Injection: Results Documented by Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Eleni Loukianou

    2010-12-01

    Full Text Available Aim:To describe a patient with a giant pigment epithelial detachment (PED secondary to exudative age-related macular degeneration (ARMD successfully treated with a single intravitreal ranibizumab (Lucentis injection (0.5 mg/0.05 ml.Methods:An 89-year-old woman presented with a six-day history of reduced vision and distortion in the left eye. Best-corrected visual acuity in that eye was 6/15. Fundoscopy revealed a giant PED and exudates temporally to the fovea. Optical coherence tomography showed a PED associated with subretinal and intraretinal fluid. Fluorescein angiography confirmed the diagnosis of an occult choroidal neovascularization. Treatment with intravitreal injections of ranibizumab (Lucentis was recommended, although the increased risk of retinal pigment epithelium (RPE rip was mentioned. Results:Four weeks after the first intravitreal Lucentis injection, the visual acuity in the left eye improved to 6/7.5, with a significant improvement of the distortion and a complete anatomical resolution of the PED confirmed by optical coherence tomography. Conclusion:Giant PED secondary to exudative ARMD can be successfully treated with intravitreal ranibizumab, despite the increased risk of RPE rip. To our knowledge, this is the first case presenting with complete resolution of PED after a single ranibizumab injection.

  1. Growth and development of Arabidopsis thaliana under single-wavelength red and blue laser light

    KAUST Repository

    Ooi, Amanda Siok Lee

    2016-09-23

    Indoor horticulture offers a sensible solution for sustainable food production and is becoming increasingly widespread. However, it incurs high energy and cost due to the use of artificial lighting such as high-pressure sodium lamps, fluorescent light or increasingly, the light-emitting diodes (LEDs). The energy efficiency and light quality of currently available horticultural lighting is suboptimal, and therefore less than ideal for sustainable and cost-effective large-scale plant production. Here, we demonstrate the use of high-powered single-wavelength lasers for indoor horticulture. They are highly energy-efficient and can be remotely guided to the site of plant growth, thus reducing on-site heat accumulation. Furthermore, laser beams can be tailored to match the absorption profiles of different plant species. We have developed a prototype laser growth chamber and demonstrate that plants grown under laser illumination can complete a full growth cycle from seed to seed with phenotypes resembling those of plants grown under LEDs reported previously. Importantly, the plants have lower expression of proteins diagnostic for light and radiation stress. The phenotypical, biochemical and proteome data show that the single-wavelength laser light is suitable for plant growth and therefore, potentially able to unlock the advantages of this next generation lighting technology for highly energy-efficient horticulture.

  2. Single-cell force spectroscopy as a technique to quantify human red blood cell adhesion to subendothelial laminin.

    Science.gov (United States)

    Maciaszek, Jamie L; Partola, Kostyantyn; Zhang, Jing; Andemariam, Biree; Lykotrafitis, George

    2014-12-18

    Single-cell force spectroscopy (SCFS), an atomic force microscopy (AFM)-based assay, enables quantitative study of cell adhesion while maintaining the native state of surface receptors in physiological conditions. Human healthy and pathological red blood cells (RBCs) express a large number of surface proteins which mediate cell-cell interactions, or cell adhesion to the extracellular matrix. In particular, RBCs adhere with high affinity to subendothelial matrix laminin via the basal cell adhesion molecule and Lutheran protein (BCAM/Lu). Here, we established SCFS as an in vitro technique to study human RBC adhesion at baseline and following biochemical treatment. Using blood obtained from healthy human subjects, we recorded adhesion forces from single RBCs attached to AFM cantilevers as the cell was pulled-off of substrates coated with laminin protein. We found that an increase in the overall cell adhesion measured via SCFS is correlated with an increase in the resultant total force measured on 1 µm(2) areas of the RBC membrane. Further, we showed that SCFS can detect significant changes in the adhesive response of RBCs to modulation of the cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) pathway. Lastly, we identified variability in the RBC adhesion force to laminin amongst the human subjects, suggesting that RBCs maintain diverse levels of active BCAM/Lu adhesion receptors. By using single-cell measurements, we established a powerful new method for the quantitative measurement of single RBC adhesion with specific receptor-mediated binding. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Pharmacokinetics of cefquinome in red-eared slider turtles (Trachemys scripta elegans) after single intravenous and intramuscular injections.

    Science.gov (United States)

    Uney, K; Altan, F; Cetin, G; Aboubakr, M; Dik, B; Sayın, Z; Er, A; Elmas, M

    2018-02-01

    The purpose of this study was to evaluate the pharmacokinetics of cefquinome (CFQ) following single intravenous (IV) or intramuscular (IM) injections of 2 mg/kg body weight in red-eared slider turtles. Plasma concentrations of CFQ were determined by high-performance liquid chromatography and analyzed using noncompartmental methods. The pharmacokinetic parameters following IV injection were as follows: elimination half-life (t 1/2λz ) 21.73 ± 4.95 hr, volume of distribution at steady-state (V dss ) 0.37 ± 0.11 L/kg, area under the plasma concentration-time curve (AUC 0-∞ ) 163 ± 32 μg hr -1  ml -1 , and total body clearance (Cl T ) 12.66 ± 2.51 ml hr -1  kg -1 . The pharmacokinetic parameters after IM injection were as follows: peak plasma concentration (C max ) 3.94 ± 0.84 μg/ml, time to peak concentration (T max ) 3 hr, t 1/2λz 26.90 ± 4.33 hr, and AUC 0-∞ 145 ± 48 μg hr -1  ml -1 . The bioavailability after IM injection was 88%. Data suggest that CFQ has a favorable pharmacokinetic profile with a long half-life and a high bioavailability in red-eared slider turtles. Further studies are needed to establish a multiple dosage regimen and evaluate clinical efficacy. © 2017 John Wiley & Sons Ltd.

  4. High-Quality Draft Single-Cell Genome Sequence Belonging to the Archaeal Candidate Division SA1, Isolated from Nereus Deep in the Red Sea

    KAUST Repository

    Ngugi, David

    2018-05-09

    Candidate division SA1 encompasses a phylogenetically coherent archaeal group ubiquitous in deep hypersaline anoxic brines around the globe. Recently, the genome sequences of two cultivated representatives from hypersaline soda lake sediments were published. Here, we present a single-cell genome sequence from Nereus Deep in the Red Sea that represents a putatively novel family within SA1.

  5. High-Quality Draft Single-Cell Genome Sequence Belonging to the Archaeal Candidate Division SA1, Isolated from Nereus Deep in the Red Sea

    KAUST Repository

    Ngugi, David; Stingl, Ulrich

    2018-01-01

    Candidate division SA1 encompasses a phylogenetically coherent archaeal group ubiquitous in deep hypersaline anoxic brines around the globe. Recently, the genome sequences of two cultivated representatives from hypersaline soda lake sediments were published. Here, we present a single-cell genome sequence from Nereus Deep in the Red Sea that represents a putatively novel family within SA1.

  6. Assembly of disperse red 1 molecules in the channels of AlPO4-5 single crystals for second-harmonic generation

    NARCIS (Netherlands)

    Jiang, FY; Lu, WX; Zhai, JP; Ye, JT; Wong, GKL; Han, Xueyao; Tang, ZK

    2006-01-01

    Disperse red 1 (DR1) molecules have been successfully incorporated into the one-dimensional channels of AlPO4-5 single crystals by means of vapor-phase diffusion. Polarizing microscope and SHG results indicate that the DR1 molecules are well aligned in a preferred direction along the crystal

  7. Surface Magnetic Fields on Giants and Supergiants

    Science.gov (United States)

    Lebre, Agnès

    2018-04-01

    After a short introduction to spectropolarimetry and the tecnics allowing for the detection of surface fields, I will review the numerous and various detections of magnetic fields at the surface of giant and supergiant stars. On Betelgeuse, the prototype of Red Supergiants, I will present recent results collected after a 10 years long spectropolarimetric survey.

  8. Genomic diversification of giant enteric symbionts reflects host dietary lifestyles

    KAUST Repository

    Ngugi, David

    2017-08-24

    Herbivorous surgeonfishes are an ecologically successful group of reef fish that rely on marine algae as their principal food source. Here, we elucidated the significance of giant enteric symbionts colonizing these fishes regarding their roles in the digestive processes of hosts feeding predominantly on polysiphonous red algae and brown Turbinaria algae, which contain different polysaccharide constituents. Using metagenomics, single-cell genomics, and metatranscriptomic analyses, we provide evidence of metabolic diversification of enteric microbiota involved in the degradation of algal biomass in these fishes. The enteric microbiota is also phylogenetically and functionally simple relative to the complex lignocellulose-degrading microbiota of terrestrial herbivores. Over 90% of the enzymes for deconstructing algal polysaccharides emanate from members of a single bacterial lineage,

  9. Charting the Giants

    Science.gov (United States)

    2004-06-01

    zero expansion asymptotically after an infinite time and has a flat geometry). All three observational tests by means of supernovae (green), the cosmic microwave background (blue) and galaxy clusters converge at a Universe around Ωm ~ 0.3 and ΩΛ ~ 0.7. The dark red region for the galaxy cluster determination corresponds to 95% certainty (2-sigma statistical deviation) when assuming good knowledge of all other cosmological parameters, and the light red region assumes a minimum knowledge. For the supernovae and WMAP results, the inner and outer regions corespond to 68% (1-sigma) and 95% certainty, respectively. References: Schuecker et al. 2003, A&A, 398, 867 (REFLEX); Tonry et al. 2003, ApJ, 594, 1 (supernovae); Riess et al. 2004, ApJ, 607, 665 (supernovae) Galaxy clusters are far from being evenly distributed in the Universe. Instead, they tend to conglomerate into even larger structures, "super-clusters". Thus, from stars which gather in galaxies, galaxies which congregate in clusters and clusters tying together in super-clusters, the Universe shows structuring on all scales, from the smallest to the largest ones. This is a relict of the very early (formation) epoch of the Universe, the so-called "inflationary" period. At that time, only a minuscule fraction of one second after the Big Bang, the tiny density fluctuations were amplified and over the eons, they gave birth to the much larger structures. Because of the link between the first fluctuations and the giant structures now observed, the unique REFLEX catalogue - the largest of its kind - allows astronomers to put considerable constraints on the content of the Universe, and in particular on the amount of dark matter that is believed to pervade it. Rather interestingly, these constraints are totally independent from all other methods so far used to assert the existence of dark matter, such as the study of very distant supernovae (see e.g. ESO PR 21/98) or the analysis of the Cosmic Microwave background (e

  10. A micro-Raman study of live, single red blood cells (RBCs treated with AgNO3 nanoparticles.

    Directory of Open Access Journals (Sweden)

    Aseefhali Bankapur

    Full Text Available Silver nanoparticles (Ag NPs are known to exhibit broad antimicrobial activity. However, such activity continues to raise concerns in the context of the interaction of such NPs with biomolecules. In a physiological environment NPs interact with individual biological cells either by penetrating through the cell membrane or by adhering to the membrane. We have explored the interaction of Ag NPs with single optically-trapped, live erythrocytes (red blood cells, RBCs using Raman Tweezers spectroscopy. Our experiments reveal that Ag NPs induce modifications within an RBC that appear to be irreversible. In particular we are able to identify that the heme conformation in an RBC transforms from the usual R-state (oxy-state to the T-state (deoxy-state. We rationalize our observations by proposing a model for the nanoparticle cytotoxicity pathway when the NP size is larger than the membrane pore size. We propose that the interaction of Ag NPs with the cell surface induces damage brought about by alteration of intracellular pH caused by the blockage of the cell membrane transport.

  11. Interspersion of highly repetitive DNA with single copy DNA in the genome of the red crab, Geryon quinquedens

    Energy Technology Data Exchange (ETDEWEB)

    Christie, N.T. (Univ. of Tennessee, Oak Ridge); Skinner, D.M.

    1979-02-01

    Kinetic analysis of the reassociation of 420 nucleotide (NT) long fragments has shown that essentially all of the repetitive sequences of the DNA of the red crab Geryon quinquedens are highly repetitive. There are negligible amounts of low and intermediate repetitive DNAs. Though atypical of most eukaryotes, this pattern has been observed in al other brachyurans (true crabs) studied. The major repetitive component is subdivided into short runs of 300 NT and longer runs of greater than 1200 NT while the minor component has an average sequence length of 400 NT. Both components reassociate at rates commonly observed for satellite DNAs. Unique among eukaryotes the organization of the genome includes single copy DNA contiguous to short runs (300 NT) of both repetitive components. Although patent satellites are not present, subsets of the repetitive DNA have been isolated by either restriction endonuclease digestion or by centrifugation in Ag/sup +/ or Hg/sup 2 +//Cs/sub 2/SO/sub 4/ density gradients.

  12. Label-free nanoscale characterization of red blood cell structure and dynamics using single-shot transport of intensity equation

    Science.gov (United States)

    Poola, Praveen Kumar; John, Renu

    2017-10-01

    We report the results of characterization of red blood cell (RBC) structure and its dynamics with nanometric sensitivity using transport of intensity equation microscopy (TIEM). Conventional transport of intensity technique requires three intensity images and hence is not suitable for studying real-time dynamics of live biological samples. However, assuming the sample to be homogeneous, phase retrieval using transport of intensity equation has been demonstrated with single defocused measurement with x-rays. We adopt this technique for quantitative phase light microscopy of homogenous cells like RBCs. The main merits of this technique are its simplicity, cost-effectiveness, and ease of implementation on a conventional microscope. The phase information can be easily merged with regular bright-field and fluorescence images to provide multidimensional (three-dimensional spatial and temporal) information without any extra complexity in the setup. The phase measurement from the TIEM has been characterized using polymeric microbeads and the noise stability of the system has been analyzed. We explore the structure and real-time dynamics of RBCs and the subdomain membrane fluctuations using this technique.

  13. Emergency transfusion of patients with unknown blood type with blood group O Rhesus D positive red blood cell concentrates: a prospective, single-centre, observational study.

    Science.gov (United States)

    Selleng, Kathleen; Jenichen, Gregor; Denker, Kathrin; Selleng, Sixten; Müllejans, Bernd; Greinacher, Andreas

    2017-05-01

    Emergency patients with unknown blood type usually receive O Rhesus D negative (RhD-) red blood cell concentrates until their blood group is determined to prevent RhD+ related adverse transfusion reactions. As 85% of individuals are RhD+, this consumption of O RhD- red blood cell concentrates contributes to shortages of O RhD- red blood cell concentrates, sometimes forcing transfusion of known RhD- patients with RhD+ red blood cell concentrates. Here we report the outcome of this transfusion policy transfusing all emergency patients with unknown blood type with O RhD+ red blood cell concentrates. In this prospective single-centre observational study done between Jan 1, 2001, and Dec 31, 2015, we assessed all consecutive RhD- patients at the University Medicine Greifswald who received RhD+ red blood cell concentrates (emergency patients with unknown blood type; and RhD- patients receiving RhD+ red blood cell concentrates during RhD- red blood cell concentrate shortages). No patients were excluded. The primary endpoint was anti-D allo-immunisation at 2 months follow-up or later. Patients were followed up and tested for immunisation against red blood cell antigens using the direct antiglobulin test and an antibody screen every 3-5 days for 4 weeks or until death, or hospital discharge. Surviving patients were screened for development of anti-D antibodies for up to 12 months (at the predefined timepoints 2, 3, 6, and 12 months) after RhD+ red blood cell transfusion. 437 emergency patients, of whom 85 (20%) were RhD-, received 2836 RhD+ red blood cell concentrates. The overall risk of inducing anti-D antibodies (in all 437 recipients) was 17 (4%, 95% CI 2·44-6·14) of 437 (assuming all patients lost to follow-up developed anti-D allo-immunisation). During this period, 110 known RhD- patients received RhD+ red blood cell concentrates during RhD- red blood cell concentrate shortages. Of these, 29 (26%; 95% CI 19·0-35·3) developed anti-D allo-immunisation (assuming all

  14. Comparison of the gravimetric, phenol red, and 14C-PEG-3350 methods to determine water absorption in the rat single-pass intestinal perfusion model

    OpenAIRE

    Sutton, Steven C.; Rinaldi, M. T. S.; Vukovinsky, K. E.

    2001-01-01

    This study was undertaken to determine whether the gravimetric method provided an accurate measure of water flux correction and to compare the gravimetric method with methods that employ nonabsorbed markers (eg, phenol red and 14C-PEG-3350). Phenol red, 14C-PEG-3350, and 4-[2-[[2-(6-amino-3-pyridinyl)-2-hydroxyethyl]amino]ethoxy]-methyl ester, (R)-benzene acetic acid (Compound I) were co-perfused in situ through the jejunum of 9 anesthetized rats (single-pass intestinal perfusion [SPIP]). Wat...

  15. Pharmacokinetics of meloxicam in red-eared slider turtles (Trachemys scripta elegans) after single intravenous and intramuscular injections.

    Science.gov (United States)

    Uney, Kamil; Altan, Feray; Aboubakr, Mohammed; Cetin, Gul; Dik, Burak

    2016-05-01

    OBJECTIVE To determine the pharmacokinetics of meloxicam after single IV and IM injections in red-eared slider turtles (Trachemys scripta elegans). ANIMALS 8 healthy red-eared slider turtles. PROCEDURES Turtles received 1 dose of meloxicam (0.2 mg/kg) IV or IM (4 turtles/route), a 30-day washout period was provided, and then turtles received the same dose by the opposite route. Blood samples were collected at predetermined times for measurement of plasma meloxicam concentration. Pharmacokinetic values for each administration route were determined with a 2-compartment open model approach. RESULTS For IV administration, mean ± SD values of major pharmacokinetic variables were 1.02 ± 0.41 hours for distribution half-life, 9.78 ± 2.23 hours for elimination half-life, 215 ± 32 mL/kg for volume of distribution at steady state, 11.27 ± 1.44 μg•h/mL for area under the plasma concentration versus time curve, and 18.00 ± 2.32 mL/h/kg for total body clearance. For IM administration, mean values were 0.35 ± 0.06 hours for absorption half-life, 0.72 ± 0.06 μg/mL for peak plasma concentration, 1.5 ± 0.0 hours for time to peak concentration, 3.73 ± 2.41 hours for distribution half-life, 13.53 ± 1.95 hours for elimination half-life, 11.33 ± 0.92 μg•h/mL for area under the plasma concentration versus time curve, and 101 ± 6% for bioavailability. No adverse reactions were detected. CONCLUSIONS AND CLINICAL RELEVANCE Long half-life, high bioavailability, and lack of immediate adverse reactions of meloxicam administered IM at 0.2 mg/kg suggested the possibility of safe and effective clinical use in turtles. Additional studies are needed to establish appropriate administration frequency and clinical efficacy.

  16. Effective tuning of the ratio of red to green emission of Ho"3"+ ions in single LiLuF_4 microparticle via codoping Ce"3"+ ions

    International Nuclear Information System (INIS)

    Gao, Wei; Dong, Jun; Liu, Jihong; Yan, Xuewen

    2016-01-01

    Yb"3"+/Ho"3"+ codoped LiLuF_4 microparticles have been successfully prepared via a facile hydrothermal method. The crystal phase and morphology of LiLuF_4 microparticles were inspected by x-ray diffraction and scanning electron microscope, respectively. The upconversion emission of single LiLuF_4: Yb"3"+/Ho"3"+ microparticle was carefully studied by a confocal microscopy setup under NIR 980 nm excitation. With the increase of Ce"3"+ ion concentrations of 12%, the ratio of red to green emission of the Ho"3"+ ions of single LiLuF_4 microparticle was boosted about 17-fold, and the output colors were tuned from green to red, which is due to the two efficient cross-relaxation between Ho"3"+ and Ce"3"+ ions enhances the red and suppresses the green in the emission processes. To investigate the optical properties of the single microparticle or nanoparticle through the confocal microscopy setup can effectively avoid the influence of surrounding particle or environment, and could provide more precise information for better exploring the emission mechanisms of rare earth ions. The tunable upconversion emission of Ho"3"+ in single LiLuF_4 microparticle in this work will have great potential applications in the micro optoelectronic devices and color display applications. - Highlights: • The optical properties of the single LiLuF4: Yb3+/Ho3+/Ce3+ microparticle were studied. • The output colors of single LiLuF4 microparticle were tuned from green to red. • The upconversion mechanisms between Ho3+ and Ce3+ ions were discussed based on emission spectrum.

  17. 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

  18. TRIUMF: Secrets of the red giant

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Results from the first nuclear astrophysics experiment with the TISOL on-line isotope separator at the Canadian TRIUMF Laboratory for the first time allow accurate estimates to be made of the production of oxygen-16 in massive stars, and hence of heavier elements in supernova explosions. Since its commissioning TISOL has been used to study properties of nuclides far from stability, similar to studies at CERN's ISOLDE. These new astrophysical results have shed light on a long-standing problem in the helium burning of massive stars and their subsequent demise by supernova explosions. Indeed, this problem has occupied many experimental and theoretical astrophysicists for the better part of the last two decades

  19. TRIUMF: Secrets of the red giant

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-10-15

    Results from the first nuclear astrophysics experiment with the TISOL on-line isotope separator at the Canadian TRIUMF Laboratory for the first time allow accurate estimates to be made of the production of oxygen-16 in massive stars, and hence of heavier elements in supernova explosions. Since its commissioning TISOL has been used to study properties of nuclides far from stability, similar to studies at CERN's ISOLDE. These new astrophysical results have shed light on a long-standing problem in the helium burning of massive stars and their subsequent demise by supernova explosions. Indeed, this problem has occupied many experimental and theoretical astrophysicists for the better part of the last two decades.

  20. Interferometric Studies of Red Giants with MAPPIT

    Science.gov (United States)

    Ireland, Michael J.

    2002-06-01

    Powerful new tools for the analysis of wavelength-dispersed aperture masking data are presented, as applied to the MAPPIT instrument of the 3.9 m Anglo-Australia Telescope. By using both baseline and wavelength bootstrapping simultaneously, solutions were found for the phase of wavefronts degraded by atmospheric and instrumental effects. This allowed coherent processing of many data sets, greatly improving signal-to-noise both at the longest baselines for well resolved objects, and at all baselines in for data in TiO absorption bands. Using this new techniques, as well as power spectrum-based techniques, wavelength-dependent diameters are found in the range 650-950 nm for the following stars: R Carinae, R Leonis, omicron Ceti, R Hydrae, W Hydrae, R Doradus, L2 Puppis, alpha Orionis, gamma Crucis, eta Carinae and VY Canis Majoris. All the Mira-like stars showed greater than 50% variation in diameter over the available wavelength range. L2 Puppis, a semi-regular variable resolved for the first time, showed a variation in diameter consistent with scattering by a recently ejected shell of dust.

  1. Barium and iron abundances in red giants

    International Nuclear Information System (INIS)

    Fernandez-Villacanas, J.L.; Rego, M.; Cornide, M.

    1990-01-01

    An intermediate-dispersion abundance analysis has been carried out on a sample of 21 barium and 14 comparison stars. The excess of barium over iron has been used as the most representative indicator of peculiarity. These excesses are higher in the peculiar stars than in the nonpeculiar stars. Particularly interesting is the case of HD 67447, included in the comparison stars, with an excess Ba/Fe abundance = 1.61, probably a new barium star. A trend indicating a possible anticorrelation between barium overabundance and metallicity favors the suggestion that the barium strong group is older than the barium weak one. 36 refs

  2. Transforming giants.

    Science.gov (United States)

    Kanter, Rosabeth Moss

    2008-01-01

    Large corporations have long been seen as lumbering, inflexible, bureaucratic--and clueless about global developments. But recently some multinationals seem to be transforming themselves: They're engaging employees, moving quickly, and introducing innovations that show true connection with the world. Harvard Business School's Kanter ventured with a research team inside a dozen global giants--including IBM, Procter & Gamble, Omron, CEMEX, Cisco, and Banco Real--to discover what has been driving the change. After conducting more than 350 interviews on five continents, she and her colleagues came away with a strong sense that we are witnessing the dawn of a new model of corporate power: The coordination of actions and decisions on the front lines now appears to stem from widely shared values and a sturdy platform of common processes and technology, not from top-down decrees. In particular, the values that engage the passions of far-flung workforces stress openness, inclusion, and making the world a better place. Through this shift in what might be called their guidance systems, the companies have become as creative and nimble as much smaller ones, even while taking on social and environmental challenges of a scale that only large enterprises could attempt. IBM, for instance, has created a nonprofit partnership, World Community Grid, through which any organization or individual can donate unused computing power to research projects and see what is being done with the donation in real time. IBM has gained an inspiring showcase for its new technology, helped business partners connect with the company in a positive way, and offered individuals all over the globe the chance to contribute to something big.

  3. Giant Cell Arteritis

    Science.gov (United States)

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  4. Comparison of the gravimetric, phenol red, and 14C-PEG-3350 methods to determine water absorption in the rat single-pass intestinal perfusion model.

    Science.gov (United States)

    Sutton, S C; Rinaldi, M T; Vukovinsky, K E

    2001-01-01

    This study was undertaken to determine whether the gravimetric method provided an accurate measure of water flux correction and to compare the gravimetric method with methods that employ nonabsorbed markers (eg, phenol red and 14C-PEG-3350). Phenol red,14C-PEG-3350, and 4-[2-[[2-(6-amino-3-pyridinyl)-2-hydroxyethyl]amino]ethoxy]-, methyl ester, (R)-benzene acetic acid (Compound I) were co-perfused in situ through the jejunum of 9 anesthetized rats (single-pass intestinal perfusion [SPIP]). Water absorption was determined from the phenol red,14C-PEG-3350, and gravimetric methods. The absorption rate constant (ka) for Compound I was calculated. Both phenol red and 14C-PEG-3350 were appreciably absorbed, underestimating the extent of water flux in the SPIP model. The average +/- SD water flux microg/h/cm) for the 3 methods were 68.9 +/- 28.2 (gravimetric), 26.8 +/- 49.2 (phenol red), and 34.9 +/- 21.9 (14C-PEG-3350). The (average +/- SD) ka for Compound I (uncorrected for water flux) was 0.024 +/- 0.005 min(-1). For the corrected, gravimetric method, the average +/- SD was 0.031 +/- 0.001 min(-1). The gravimetric method for correcting water flux was as accurate as the 2 "nonabsorbed" marker methods.

  5. Determination of giant resonance strengths

    International Nuclear Information System (INIS)

    Serr, F.E.

    1983-01-01

    Using theoretical strength functions to describe the different giant resonances expected at excitation energies of the order of (60-85)/Asup(1/3) MeV, we calculate the double differential cross sections d 2 sigma/dΩ dE associated with the reactions 208 Pb(α, α') and 90 Zr(α, α') (Esub(α) = 152 MeV). The angular distributions for the giant quadrupole and giant monopole resonances obtained from fits to these spectra, making simple, commonly used assumptions for the peak shapes and background, are compared to the original angular distributions. The differences between them are an indication of some of the uncertainties affecting the giant resonance strengths extracted from hadron inelastic scattering data. Fits to limited angular regions lead to errors of up to 50% in the value of the energy-weighted sum rule, depending on the angles examined. While it seems possible to extract the correct EWSR for the GMR by carrying out the analyses at 0 0 , no single privileged angle seems to exist in the case of the GQR. (orig.)

  6. Nursery of Giants

    Science.gov (United States)

    2004-01-01

    Hidden behind a shroud of dust in the constellation Cygnus is a stellar nursery called DR21, which is giving birth to some of the most massive stars in our galaxy. Visible light images reveal no trace of this interstellar cauldron because of heavy dust obscuration. In fact, visible light is attenuated in DR21 by a factor of more than 10,000,000,000,000,000,000,000,000,000,000,000,000,000 (ten thousand trillion heptillion). New images from NASA's Spitzer Space Telescope allow us to peek behind the cosmic veil and pinpoint one of the most massive natal stars yet seen in our Milky Way galaxy. The never-before-seen star is 100,000 times as bright as the Sun. Also revealed for the first time is a powerful outflow of hot gas emanating from this star and bursting through a giant molecular cloud. This image is a large-scale mosaic assembled from individual photographs obtained with the InfraRed Array Camera (IRAC) aboard Spitzer. The image covers an area about two times that of a full moon. The mosaic is a composite of images obtained at mid-infrared wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red). The brightest infrared cloud near the top center corresponds to DR21, which presumably contains a cluster of newly forming stars at a distance of 10,000 light-years. Protruding out from DR21 toward the bottom left of the image is a gaseous outflow (green), containing both carbon monoxide and molecular hydrogen. Data from the Spitzer spectrograph, which breaks light into its constituent individual wavelengths, indicate the presence of hot steam formed as the outflow heats the surrounding molecular gas. Outflows are physical signatures of processes that create supersonic beams, or jets, of gas. They are usually accompanied by discs of material around the new star, which likely contain the materials from which future planetary systems are formed. Additional newborn stars, depicted in green, can be seen surrounding the DR21 region

  7. LITHIUM-RICH GIANTS IN GLOBULAR CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Evan N.; Cohen, Judith G. [California Institute of Technology, 1200 E. California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Guhathakurta, Puragra [UCO/Lick Observatory and Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Zhang, Andrew J. [The Harker School, 500 Saratoga Avenue, San Jose, CA 95129 (United States); Hong, Jerry [Palo Alto High School, 50 Embarcadero Road, Palo Alto, CA, 94301 (United States); Guo, Michelle [Stanford University, 450 Serra Mall, Stanford, CA 94305 (United States); Guo, Rachel [Irvington High School, 41800 Blacow Road, Fremont, CA 94538 (United States); Cunha, Katia [Observatório Nacional, São Cristóvão Rio de Janeiro (Brazil)

    2016-03-10

    Although red giants deplete lithium on their surfaces, some giants are Li-rich. Intermediate-mass asymptotic giant branch (AGB) stars can generate Li through the Cameron–Fowler conveyor, but the existence of Li-rich, low-mass red giant branch (RGB) stars is puzzling. Globular clusters are the best sites to examine this phenomenon because it is straightforward to determine membership in the cluster and to identify the evolutionary state of each star. In 72 hours of Keck/DEIMOS exposures in 25 clusters, we found four Li-rich RGB and two Li-rich AGB stars. There were 1696 RGB and 125 AGB stars with measurements or upper limits consistent with normal abundances of Li. Hence, the frequency of Li-richness in globular clusters is (0.2 ± 0.1)% for the RGB, (1.6 ± 1.1)% for the AGB, and (0.3 ± 0.1)% for all giants. Because the Li-rich RGB stars are on the lower RGB, Li self-generation mechanisms proposed to occur at the luminosity function bump or He core flash cannot explain these four lower RGB stars. We propose the following origin for Li enrichment: (1) All luminous giants experience a brief phase of Li enrichment at the He core flash. (2) All post-RGB stars with binary companions on the lower RGB will engage in mass transfer. This scenario predicts that 0.1% of lower RGB stars will appear Li-rich due to mass transfer from a recently Li-enhanced companion. This frequency is at the lower end of our confidence interval.

  8. Incidence of single and mixed infections with Eimeria kofoidi, E. caucasica and E. legionensis on the health of experimentally infected red-legged partridges (Alectoris rufa).

    Science.gov (United States)

    Naciri, M; Fort, G; Briant, J; Duperray, J; Benzoni, G

    2014-09-15

    Little is known about Eimeria-induced coccidiosis in partridges. After a coccidiosis outbreak in a farm rearing red-legged partridges (Alectoris rufa) in Brittany (France), three Eimeria species were identified as Eimeria kofoidi, Eimeria caucasica and Eimeria legionensis. This study aimed to reproduce the effects of the disease occurring in field conditions, in the absence of preventive treatments, to further build a coccidiosis model, helpful for coccidiostatic development. The pathogenic effects of a single infection with Eimeria kofoidi, E. caucasica and E. legionensis were evaluated, as well as the effects of multiple infections associating two or three of these species in red-legged partridges. Thirty-one-day-old birds were individually inoculated with Eimeria spp. and clinically followed up until 49 days of age. Mortality, lesion scores, daily oocyst production and growth were used as assessment criteria. Single infections with 250,000 E. kofoidi, 30,000 E. caucasica or 100,000 E. legionensis oocysts did not increase mortality rate compared to uninfected birds, whereas the combination of 3 species caused significant 28% mortality (PEimeria spp. or for selecting efficient molecules to struggle coccidiosis of red-legged partridges. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Effects of local single and fractionated X-ray doses on rat bone marrow blood flow and red blood cell volume

    International Nuclear Information System (INIS)

    Pitkaenen, M.A.; Hopewell, J.W.

    1985-01-01

    Time and dose dependent changes in blood flow and red blood cell volume were studied in the locally irradiated bone marrow of the rat femur after single and fractionated doses of X-rays. With the single dose of 10 Gy the bone marrow blood flow although initially reduced returned to the control levels by seven months after irradiation. With doses >=15 Gy the blood flow was still significantly reduced at seven months. The total dose levels predicted by the nominal standard dose equation for treatments in three, six or nine fractions produced approximately the same degree of reduction in the bone marrow blood flow seven months after the irradiation. However, the fall in the red blood cell volume was from 23 to 37% greater in the three fractions groups compared with that in the nine fractions groups. Using the red blood cell volume as a parameter the nominal standard dose formula underestimated the severity of radiation damage in rat bone marrow at seven months for irradiation with small numbers of large dose fractions. (orig.) [de

  10. Measuring Precise Radii of Giants Orbiting Giants to Distinguish Between Planet Evolution Models

    Science.gov (United States)

    Grunblatt, Samuel; Huber, Daniel; Lopez, Eric; Gaidos, Eric; Livingston, John

    2017-10-01

    Despite more than twenty years since the initial discovery of highly irradiated gas giant planets, the mechanism for planet inflation remains unknown. However, proposed planet inflation mechanisms can now be separated into two general classes: those which allow for post-main sequence planet inflation by direct irradiation from the host star, and those which only allow for slowed cooling of the planet over its lifetime. The recent discovery of two inflated warm Jupiters orbiting red giant stars with the NASA K2 Mission allows distinction between these two classes, but uncertainty in the planet radius blurs this distinction. Observing transits of these planets with the Spitzer Space Telescope would reduce stellar variability and thus planet radius uncertainties by approximately 50% relative to K2, allowing distinction between the two planet inflation model classes at a 3-sigma level. We propose to observe one transit of both known warm Jupiters orbiting red giant stars, K2-97b and EPIC228754001.01, to distinguish between planet model inflation classes and measure the planetary heating efficiency to 3-sigma precision. These systems are benchmarks for the upcoming NASA TESS Mission, which is predicted to discover an order of magnitude more red giant planet systems after launching next year.

  11. Factors Affecting the Recurrence of Giant Cell Tumor of Bone After Surgery: A Clinicopathological Study of 80 Cases from a Single Center

    Directory of Open Access Journals (Sweden)

    Dong-dong Cheng

    2015-07-01

    Full Text Available Background/Aims: This aim of the present study was to identify specific markers determining the recurrence of the giant cell tumor of bone (GCTB. Methods: This study involved the clinicopathological analysis of 80 cases. All of the clinical features, pathological fracture, Campanacci grade, histological features and surgical methods were reviewed. Immunohistochemistry was used to detect the expression of Ki-67, CD147, mutant p53 and p63 in GCTB. Comparisons between different groups were performed using the Chi-square test. The risk factors affecting recurrence were analyzed using a binary logistic model. Kaplan-Meier analysis was employed for the survival analysis between the groups. Cell proliferation assays, migration and invasion assays were used to detect the function of CD147 on GCTB in vitro. Results: The univariate analysis showed that Ki-67 and CD147 expression, pathological fracture, Campanacci grade and surgical method were associated with recurrence. The multivariate analysis revealed that CD147 expression, Campanacci grade and surgical method were the factors affecting GCTB recurrence. In addition, the Kaplan-Meier analysis revealed that these factors affected tumor-free survival time. In vitro study revealed that the CD147 knockdown by small interfering RNA (siRNA technique dramatically reduced the proliferation, migration and invasion of GCTB. Conclusion: Our results suggest that CD147 may serve as an adequate marker for GCTB recurrence. Campanacci grade is a risk factor for GCTB recurrence, which is also affected by the surgical method used.

  12. Nanodielectrics with giant permittivity

    Indian Academy of Sciences (India)

    Following the prediction, during the last couple of years we have investigated the effect of giant permittivity in one-dimensional systems of conventional metals and conjugated polymer chains. In this article, we have tried to summarize the works on giant permittivity and finally the fabrication of nanocapacitor using metal ...

  13. 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.

  14. Giant pediatric cervicofacial lymphatic malformations.

    Science.gov (United States)

    Benazzou, Salma; Boulaadas, Malik; Essakalli, Leila

    2013-07-01

    Lymphatic malformations (LMs) are benign lesions. Most of them are found in head and neck regions as asymptomatic mass, but giant lymphangiomas may affect breathing or swallowing and constitute a major therapeutic challenge. A retrospective analysis of giant head and neck LMs with impairment of respiration or swallow for the past 11 years was performed in the Department of Maxillofacial Surgery and ENT of the Avicenne Medical University Center. Seven patients with large and extensive LMs of the head and neck were identified. There were 3 males and 4 females with a mean age of 6 years. The predominant reason for referral was airway compromise necessitating tracheostomy (57%) and dysphagia (43%). Three patients had macrocystic lesions; others were considered mixed or microcystic. All the patients underwent surgical excision as a primary treatment modality. Complete surgical resection was realized in 4 patients, and subtotal resection in 3 patients. Of 7 patients, 4 patients had complications including nerve damage and recurrence of the disease. The majority of the patients underwent only a single surgical procedure. Cervicofacial LMs in children should be managed in multidisciplinary setting. Surgery remains the first treatment for managing giant, life-threatening lesions.

  15. Red blood cell alloimmunization in patients with sickle cell disease in Turkey: a single center retrospective cohort study

    Directory of Open Access Journals (Sweden)

    Soner Solmaz

    2016-12-01

    Results: Of 216 SCD patients included in the study. Alloimmunization was detected in 67 (31.0% out of 216 patients who underwent transfusion, and in 17 (30.4% out of 56 patients in Group 1 and in 50 (31.3% out of 160 patients in Group 2. When the patients were analyzed according to alloimmunization development, our study revealed that neither SCD complications are a risk factor for alloimmunization nor alloimmunization increases mortality rates. Conclusion: High alloimmunization frequency found in our study suggests the insufficient adherence of alloimmunization-prevention policies in RBC transfusions performed except experienced institutions. Therefore alloimmunization may be reduced or prevented through performing extended red cell typing among SCD patients. [Cukurova Med J 2016; 41(4.000: 622-627

  16. Analysis of giant electrorheological fluids.

    Science.gov (United States)

    Seo, Youngwook P; Seo, Yongsok

    2013-07-15

    The yield stress dependence on electric field strength for giant electrorheological (GER) fluids over the full range of electric fields was examined using Seo's scaling function which incorporated both the polarization and the conductivity models. If a proper scaling was applied to the yield stress data to collapse them onto a single curve, the Seo's scaling function could correctly fit the yield stress behavior of GER suspensions, even at very high electric field strengths. The model predictions were also compared with recently proposed Choi et al.'s model to allow a consideration of the universal framework of ER fluids. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Study of giant resonances with pions

    International Nuclear Information System (INIS)

    Baer, H.W.

    1984-01-01

    Recent results on giant resonances obtained with pion-inelastic scattering and with single- and double-charge-exchange scattering are reviewed. The states discussed are isobaric analog states, double-isobaric analog states, and isovector L = 0, 1, and 2 collective states. 36 references

  18. Light-induced energetic decoupling as a mechanism for phycobilisome-related energy dissipation in red algae: a single molecule study.

    Directory of Open Access Journals (Sweden)

    Lu-Ning Liu

    Full Text Available BACKGROUND: Photosynthetic organisms have developed multiple protective mechanisms to prevent photodamage in vivo under high-light conditions. Cyanobacteria and red algae use phycobilisomes (PBsomes as their major light-harvesting antennae complexes. The orange carotenoid protein in some cyanobacteria has been demonstrated to play roles in the photoprotective mechanism. The PBsome-itself-related energy dissipation mechanism is still unclear. METHODOLOGY/PRINCIPAL FINDINGS: Here, single-molecule spectroscopy is applied for the first time on the PBsomes of red alga Porphyridium cruentum, to detect the fluorescence emissions of phycoerythrins (PE and PBsome core complex simultaneously, and the real-time detection could greatly characterize the fluorescence dynamics of individual PBsomes in response to intense light. CONCLUSIONS/SIGNIFICANCE: Our data revealed that strong green-light can induce the fluorescence decrease of PBsome, as well as the fluorescence increase of PE at the first stage of photobleaching. It strongly indicated an energetic decoupling occurring between PE and its neighbor. The fluorescence of PE was subsequently observed to be decreased, showing that PE was photobleached when energy transfer in the PBsomes was disrupted. In contrast, the energetic decoupling was not observed in either the PBsomes fixed with glutaraldehyde, or the mutant PBsomes lacking B-PE and remaining b-PE. It was concluded that the energetic decoupling of the PBsomes occurs at the specific association between B-PE and b-PE within the PBsome rod. Assuming that the same process occurs also at the much lower physiological light intensities, such a decoupling process is proposed to be a strategy corresponding to PBsomes to prevent photodamage of the photosynthetic reaction centers. Finally, a novel photoprotective role of gamma-subunit-containing PE in red algae was discussed.

  19. Comparison of the urinary excretion of quercetin glycosides from red onion and aglycone from dietary supplements in healthy subjects: a randomized, single-blinded, cross-over study.

    Science.gov (United States)

    Shi, Yuanlu; Williamson, Gary

    2015-05-01

    Some intervention studies have shown that quercetin supplementation can regulate certain biomarkers, but it is not clear how the doses given relate to dietary quercetin (e.g. from onion). We conducted a two-period, two-sequence crossover study to compare the bioavailability of quercetin when administered in the form of a fresh red onion meal (naturally glycosylated quercetin) or dietary supplement (aglycone quercetin) under fasting conditions. Six healthy, non-smoking, adult males with BMI 22.7 ± 4.0 kg m(-2) and age 35.3 ± 12.3 y were grouped to take the two study meals in random order. In each of the 2 study periods, one serving of onion soup (made from 100 g fresh red onion, providing 156.3 ± 3.4 μmol (47 mg) quercetin) or a single dose of a quercetin dihydrate tablet (1800 ± 150 μmol (544 mg) of quercetin) were administered following 3 d washout. Urine samples were collected up to 24 h, and after enzyme deconjugation, quercetin was quantified by LC-MS. The 24 h urinary excretion of quercetin (1.69 ± 0.79 μmol) from red onion in soup was not significantly different to that (1.17 ± 0.44 μmol) for the quercetin supplement tablet (P = 0.065, paired t-test). This means that, in practice, 166 mg of quercetin supplement would be comparable to about 10 mg of quercetin aglycone equivalents from onion. These data allow intervention studies on quercetin giving either food or supplements to be more effectively compared.

  20. Lipase polystyrene giant amphiphiles.

    Science.gov (United States)

    Velonia, Kelly; Rowan, Alan E; Nolte, Roeland J M

    2002-04-24

    A new type of giant amphiphilic molecule has been synthesized by covalently connecting a lipase enzyme headgroup to a maleimide-functionalized polystyrene tail (40 repeat units). The resulting biohybrid forms catalytic micellar rods in water.

  1. Metaphyseal giant cell tumor

    International Nuclear Information System (INIS)

    Pereira, L.F.; Hemais, P.M.P.G.; Aymore, I.L.; Carmo, M.C.R. do; Cunha, M.E.P.R. da; Resende, C.M.C.

    1986-01-01

    Three cases of metaphyseal giant cell tumor are presented. A review of the literature is done, demostrating the lesion is rare and that there are few articles about it. Age incidence and characteristics of the tumor are discussed. (Author) [pt

  2. Giant CP stars

    International Nuclear Information System (INIS)

    Loden, L.O.; Sundman, A.

    1989-01-01

    This study is part of an investigation of the possibility of using chemically peculiar (CP) stars to map local galactic structure. Correct luminosities of these stars are therefore crucial. CP stars are generally regarded as main-sequence or near-main-sequence objects. However, some CP stars have been classified as giants. A selection of stars, classified in literature as CP giants, are compared to normal stars in the same effective temperature interval and to ordinary 'non giant' CP stars. There is no clear confirmation of a higher luminosity for 'CP giants', than for CP stars in general. In addition, CP characteristics seem to be individual properties not repeated in a component star or other cluster members. (author). 50 refs., 5 tabs., 3 figs

  3. Young α-enriched giant stars in the solar neighbourhood

    DEFF Research Database (Denmark)

    Martig, Marie; Rix, Hans-Walter; Aguirre, Victor Silva

    2015-01-01

    We derive age constraints for 1639 red giants in the APOKASC sample for which seismic parameters from Kepler, as well as effective temperatures, metallicities and [alpha/Fe] values from APOGEE DR12 (Apache Point Observatory Galactic Evolution Experiment Data Release 12) are available. We investig...

  4. Tuning into single-band red upconversion luminescence in Yb(3+)/Ho(3+) activated nano-glass-ceramics through Ce(3+) doping.

    Science.gov (United States)

    Chen, Daqin; Zhou, Yang; Wan, Zhongyi; Ji, Zhenguo; Huang, Ping

    2015-03-28

    Yb(3+)/Ho(3+) activated glass ceramics containing β-YF3 nanocrystals were successfully fabricated. The green ((5)S2/(5)F4→(5)I8) upconversion emission is dominant in the glass ceramics and is about 160 times stronger than that of the precursor glass, resulting from the partition of lanthanide activators into a low-phonon-energy crystalline lattice and the subsequent low probability of multi-phonon nonradiative relaxation from the (5)S2/(5)F4 and (5)I6 states to the lower ones. Upon the introduction of Ce(3+) ions into nano-glass-ceramics, two efficient cross-relaxation processes between Ho(3+) and Ce(3+), i.e., Ho(3+):(5)S2/(5)F4 + Ce(3+):(2)F5/2→Ho(3+):(5)F5 + Ce(3+):(2)F7/2 and Ho(3+):(5)I6 + Ce(3+):(2)F5/2→Ho(3+):(5)I7 + Ce(3+):(2)F7/2, are demonstrated to greatly suppress the population of the green-emitting (5)S2/(5)F4 state and to enhance the population of the red-emitting (5)F5 one, leading to the intense single-band red UC radiation of Ho(3+).

  5. ON THE SERENDIPITOUS DISCOVERY OF A Li-RICH GIANT IN THE GLOBULAR CLUSTER NGC 362

    Energy Technology Data Exchange (ETDEWEB)

    D’Orazi, Valentina; Gratton, Raffaele G.; Lucatello, Sara; Momany, Yazan [INAF—Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122, Padova (Italy); Angelou, George C. [Max Planck Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Bragaglia, Angela; Carretta, Eugenio; Sollima, Antonio [INAF—Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127, Bologna (Italy); Lattanzio, John C., E-mail: valentina.dorazi@oapd.inaf.it [Monash Centre for Astrophysics (MoCA), Monash University, Melbourne, VIC 3800 (Australia)

    2015-03-10

    We have serendipitously identified the first lithium-rich giant star located close to the red giant branch bump in a globular cluster. Through intermediate-resolution FLAMES spectra we derived a lithium abundance of A(Li) = 2.55 (assuming local thermodynamical equilibrium), which is extremely high considering the star’s evolutionary stage. Kinematic and photometric analysis confirm the object as a member of the globular cluster NGC 362. This is the fourth Li-rich giant discovered in a globular cluster, but is the only one known to exist at a luminosity close to the bump magnitude. The three previous detections are clearly more evolved, located close to, or beyond, the tip of their red giant branch. Our observations are able to discard the accretion of planets/brown dwarfs, as well as an enhanced mass-loss mechanism as a formation channel for this rare object. While the star sits just above the cluster bump luminosity, its temperature places it toward the blue side of the giant branch in the color–magnitude diagram. We require further dedicated observations to unambiguously identify the star as a red giant: we are currently unable to confirm whether Li production has occurred at the bump of the luminosity function or if the star is on the pre-zero-age horizontal branch. The latter scenario provides the opportunity for the star to have synthesized Li rapidly during the core helium flash or gradually during its red giant branch ascent via some extra mixing process.

  6. Pharmacokinetics of buprenorphine after single-dose subcutaneous administration in red-eared sliders (Trachemys scripta elegans).

    Science.gov (United States)

    Kummrow, Maya S; Tseng, Florina; Hesse, Leah; Court, Michael

    2008-12-01

    Buprenorphine, a mu opioid receptor agonist, is expected to be a suitable analgesic drug for use in reptiles. However, to date, dosage recommendations have been based on anecdotal observations. The aim of this study was to provide baseline pharmacokinetic data in red-eared sliders (Trachemys scripta elegans) targeting a plasma level of 1 ng/ml reported effective for analgesia in humans. Serial blood samples were taken after subcutaneous injection of buprenorphine, and plasma buprenorphine levels were measured by radioimmunoassay. Pharmacokinetic parameters of a lower dose (0.02 mg/kg) injected into the forelimb were compared with a higher dose (0.05 mg/kg) given in the same forelimb as well as a lower dose (0.02 mg/kg) given in the hind limb of the same animals with 2 wk between studies. After administration of 0.05 mg/kg in the front limb, 85% of animals maintained the minimum effective plasma level for 24 hr, while only 43% of animals maintained this level after 0.02 mg/kg. After hind limb injection at 0.02 mg/kg, maximum plasma concentrations and areas under the buprenorphine concentration-time curve were less than 20% and 70%, respectively, of values after forelimb injection, consistent with substantial first pass extraction by the liver. Furthermore, a secondary rise in the buprenorphine level was found after having only a hind limb injection, probably from enterohepatic recirculation of glucuronidated drug. In conclusion, buprenorphine dosages of at least 0.075 mg/kg s.i.d. should be appropriate for evaluation of analgesia efficacy, and front limb administration may be preferable to hind limb administration for optimal drug exposure.

  7. Photocatalytic degradation of Basic Red 46 and Basic Yellow 28 in single and binary mixture by UV/TiO2/periodate system

    International Nuclear Information System (INIS)

    Goezmen, Belgin; Turabik, Meral; Hesenov, Arif

    2009-01-01

    The present study deals with the investigation of photocatalytic degradation and mineralization of C.I. Basic Red 46 (BR46) and C.I. Basic Yellow 28 (BY28) dyes in single and binary solutions as a function of periodate ion concentration (IO 4 - ), irradiation time, initial pH and initial dye concentrations. First order derivative spectrophotometric method was used for to simultaneous analysis of BY28 and BR46 in binary mixtures. Langmuir-Hinshelwood kinetic model was applied to experimental data and apparent reaction rate constant values were calculated. The apparent degradation rate constant values of BR46 were higher than those of BY28 for all experiments in single dye solutions. On the other hand, the significant reductions were observed for the apparent degradation rate constant values of the BR46 in the presence of BY28 in binary solutions whereas TOC removal efficiency slightly enhanced in binary system. The highest TOC removal efficiency was obtained at pH 3.0 by adding 5 mM periodate ion in to the solution in the presence of 1 g/L TiO 2 for both dye solutions. After 3 h illumination, 68, 76 and 75% mineralization were found for 100 mg/L BY28, 100 mg/L BR46 and 50 + 50 mg/L mixed solutions, respectively.

  8. Mining a database of single amplified genomes from Red Sea brine pool extremophiles—improving reliability of gene function prediction using a profile and pattern matching algorithm (PPMA)

    Science.gov (United States)

    Grötzinger, Stefan W.; Alam, Intikhab; Ba Alawi, Wail; Bajic, Vladimir B.; Stingl, Ulrich; Eppinger, Jörg

    2014-01-01

    Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs) and poor homology of novel extremophile's genomes pose significant challenges for the attribution of functions to the coding sequences identified. The anoxic deep-sea brine pools of the Red Sea are a promising source of novel enzymes with unique evolutionary adaptation. Sequencing data from Red Sea brine pool cultures and SAGs are annotated and stored in the Integrated Data Warehouse of Microbial Genomes (INDIGO) data warehouse. Low sequence homology of annotated genes (no similarity for 35% of these genes) may translate into false positives when searching for specific functions. The Profile and Pattern Matching (PPM) strategy described here was developed to eliminate false positive annotations of enzyme function before progressing to labor-intensive hyper-saline gene expression and characterization. It utilizes InterPro-derived Gene Ontology (GO)-terms (which represent enzyme function profiles) and annotated relevant PROSITE IDs (which are linked to an amino acid consensus pattern). The PPM algorithm was tested on 15 protein families, which were selected based on scientific and commercial potential. An initial list of 2577 enzyme commission (E.C.) numbers was translated into 171 GO-terms and 49 consensus patterns. A subset of INDIGO-sequences consisting of 58 SAGs from six different taxons of bacteria and archaea were selected from six different brine pool environments. Those SAGs code for 74,516 genes, which were independently scanned for the GO-terms (profile filter) and PROSITE IDs (pattern filter). Following stringent reliability filtering, the non-redundant hits (106 profile hits and 147 pattern hits) are classified as reliable, if at least two relevant descriptors (GO-terms and/or consensus patterns) are present. Scripts for annotation, as well as for the PPM algorithm, are available

  9. Mining a database of single amplified genomes from Red Sea brine pool extremophiles – Improving reliability of gene function prediction using a profile and pattern matching algorithm (PPMA

    Directory of Open Access Journals (Sweden)

    Stefan Wolfgang Grötzinger

    2014-04-01

    Full Text Available Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs and poor homology of novel extremophile’s genomes pose significant challenges for the attribution of functions to the coding sequences identified. The anoxic deep-sea brine pools of the Red Sea are a promising source of novel enzymes with unique evolutionary adaptation. Sequencing data from Red Sea brine pool cultures and SAGs are annotated and stored in the INDIGO data warehouse. Low sequence homology of annotated genes (no similarity for 35% of these genes may translate into false positives when searching for specific functions. The Profile & Pattern Matching (PPM strategy described here was developed to eliminate false positive annotations of enzyme function before progressing to labor-intensive hyper-saline gene expression and characterization. It utilizes InterPro-derived Gene Ontology (GO-terms (which represent enzyme function profiles and annotated relevant PROSITE IDs (which are linked to an amino acid consensus pattern. The PPM algorithm was tested on 15 protein families, which were selected based on scientific and commercial potential. An initial list of 2,577 E.C. numbers was translated into 171 GO-terms and 49 consensus patterns. A subset of INDIGO-sequences consisting of 58 SAGs from six different taxons of bacteria and archaea were selected from 6 different brine pool environments. Those SAGs code for 74,516 genes, which were independently scanned for the GO-terms (profile filter and PROSITE IDs (pattern filter. Following stringent reliability filtering, the non-redundant hits (106 profile hits and 147 pattern hits are classified as reliable, if at least two relevant descriptors (GO-terms and/or consensus patterns are present. Scripts for annotation, as well as for the PPM algorithm, are available through the INDIGO website.

  10. Mining a database of single amplified genomes from Red Sea brine pool extremophiles-improving reliability of gene function prediction using a profile and pattern matching algorithm (PPMA).

    KAUST Repository

    Grötzinger, Stefan W.

    2014-04-07

    Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs) and poor homology of novel extremophile\\'s genomes pose significant challenges for the attribution of functions to the coding sequences identified. The anoxic deep-sea brine pools of the Red Sea are a promising source of novel enzymes with unique evolutionary adaptation. Sequencing data from Red Sea brine pool cultures and SAGs are annotated and stored in the Integrated Data Warehouse of Microbial Genomes (INDIGO) data warehouse. Low sequence homology of annotated genes (no similarity for 35% of these genes) may translate into false positives when searching for specific functions. The Profile and Pattern Matching (PPM) strategy described here was developed to eliminate false positive annotations of enzyme function before progressing to labor-intensive hyper-saline gene expression and characterization. It utilizes InterPro-derived Gene Ontology (GO)-terms (which represent enzyme function profiles) and annotated relevant PROSITE IDs (which are linked to an amino acid consensus pattern). The PPM algorithm was tested on 15 protein families, which were selected based on scientific and commercial potential. An initial list of 2577 enzyme commission (E.C.) numbers was translated into 171 GO-terms and 49 consensus patterns. A subset of INDIGO-sequences consisting of 58 SAGs from six different taxons of bacteria and archaea were selected from six different brine pool environments. Those SAGs code for 74,516 genes, which were independently scanned for the GO-terms (profile filter) and PROSITE IDs (pattern filter). Following stringent reliability filtering, the non-redundant hits (106 profile hits and 147 pattern hits) are classified as reliable, if at least two relevant descriptors (GO-terms and/or consensus patterns) are present. Scripts for annotation, as well as for the PPM algorithm, are available

  11. Giant nuclear resonances

    International Nuclear Information System (INIS)

    Snover, K.A.

    1989-01-01

    Giant nuclear resonances are elementary mods of oscillation of the whole nucleus, closely related to the normal modes of oscillation of coupled mechanical systems. They occur systematically in most if not all nuclei, with oscillation energies typically in the range 10-30 MeV. One of the best - known examples is the giant electric dipole (El) resonance, in which all the protons and all the neutrons oscillate with opposite phase, producing a large time - varying electric dipole moment which acts as an effective antenna for radiating gamma ray. This paper discusses this mode as well as quadrupole and monopole modes

  12. Large Mn25 single-molecule magnet with spin S = 51/2: magnetic and high-frequency electron paramagnetic resonance spectroscopic characterization of a giant spin state.

    Science.gov (United States)

    Murugesu, Muralee; Takahashi, Susumu; Wilson, Anthony; Abboud, Khalil A; Wernsdorfer, Wolfgang; Hill, Stephen; Christou, George

    2008-10-20

    The synthesis and structural, spectroscopic, and magnetic characterization of a Mn25 coordination cluster with a large ground-state spin of S = 51/2 are reported. Reaction of MnCl2 with pyridine-2,6-dimethanol (pdmH2) and NaN3 in MeCN/MeOH gives the mixed valence cluster [Mn25O18(OH)2(N3)12(pdm)6(pdmH)6]Cl2 (1; 6Mn(II), 18Mn(III), Mn(IV)), which has a barrel-like cage structure. Variable temperature direct current (dc) magnetic susceptibility data were collected in the 1.8-300 K temperature range in a 0.1 T field. Variable-temperature and -field magnetization (M) data were collected in the 1.8-4.0 K and 0.1-7 T ranges and fit by matrix diagonalization assuming only the ground state is occupied at these temperatures. The fit parameters were S = 51/2, D = -0.020(2) cm(-1), and g = 1.87(3), where D is the axial zero-field splitting parameter. Alternating current (ac) susceptibility measurements in the 1.8-8.0 K range and a 3.5 G ac field oscillating at frequencies in the 50-1500 Hz range revealed a frequency-dependent out-of-phase (chi(M)'') signal below 3 K, suggesting 1 to be a single-molecule magnet (SMM). This was confirmed by magnetization vs dc field sweeps, which exhibited hysteresis loops but with no clear steps characteristic of resonant quantum tunneling of magnetization (QTM). However, magnetization decay data below 1 K were collected and used to construct an Arrhenius plot, and the fit of the thermally activated region above approximately 0.5 K gave U(eff)/k = 12 K, where U(eff) is the effective relaxation barrier. The g value and the magnitude and sign of the D value were independently confirmed by detailed high-frequency electron paramagnetic resonance (HFEPR) spectroscopy on polycrystalline samples. The combined studies confirm both the high ground-state spin S = 51/2 of complex 1 and that it is a SMM that, in addition, exhibits QTM.

  13. The Role of Symbiotic Zooxanthellae on Giant Clam Nutrition

    OpenAIRE

    Ambariyanto

    1997-01-01

    Zooxanthellae, Symbiodinium sp, are single cell dinoflagellate algae known to live in association with many marine invertebrates such as hermatypic corals, sea anemones, jellyfish and giant clams (family Tridacnidae). In giant clams, these photosynthetic algae are located in a tubular system (known as Z tube system) which occurs within the clams. Apart from filter feeding, the nutrition of the clams is provided by zooxanthellae. These algae are capable of translocating part of their photosynt...

  14. Multifocal tenosynovial giant cell tumors in a child with Noonan syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, Arthur B. [Children' s Hospital of Wisconsin, Department of Radiology, Milwaukee, WI (United States); Nemours Children' s Health System/Nemours Children' s Hospital, Department of Radiology, Orlando, FL (United States); Awomolo, Agboola O. [Children' s Hospital of Wisconsin, Department of Radiology, Milwaukee, WI (United States); Szabo, Sara [Medical College of Wisconsin and Children' s Hospital of Wisconsin, Department of Pathology, Milwaukee, WI (United States); Cincinnati Children' s Hospital Medical Center, Division of Pathology and Laboratory Medicine, Cincinnati, OH (United States)

    2017-03-15

    Noonan syndrome is a genetic disorder with variable expression of distinctive facial features, webbed neck, chest deformity, short stature, cryptorchidism and congenital heart disease. The association of Noonan syndrome and giant cell granulomas of the mandible is widely reported. However, Noonan syndrome may also be associated with single or multifocal tenosynovial giant cell tumors, also referred to as pigmented villonodular synovitis. We report a child with Noonan syndrome, giant cell granulomas of the mandible and synovial and tenosynovial giant cell tumors involving multiple joints and tendon sheaths who was initially misdiagnosed with juvenile idiopathic arthritis. It is important for radiologists to be aware of the association of Noonan syndrome and multifocal giant cell lesions, which can range from the more commonly described giant cell granulomas of the mandible to isolated or multifocal intra- or extra-articular tenosynovial giant cell tumors or a combination of all of these lesions. (orig.)

  15. Multifocal tenosynovial giant cell tumors in a child with Noonan syndrome.

    Science.gov (United States)

    Meyers, Arthur B; Awomolo, Agboola O; Szabo, Sara

    2017-03-01

    Noonan syndrome is a genetic disorder with variable expression of distinctive facial features, webbed neck, chest deformity, short stature, cryptorchidism and congenital heart disease. The association of Noonan syndrome and giant cell granulomas of the mandible is widely reported. However, Noonan syndrome may also be associated with single or multifocal tenosynovial giant cell tumors, also referred to as pigmented villonodular synovitis. We report a child with Noonan syndrome, giant cell granulomas of the mandible and synovial and tenosynovial giant cell tumors involving multiple joints and tendon sheaths who was initially misdiagnosed with juvenile idiopathic arthritis. It is important for radiologists to be aware of the association of Noonan syndrome and multifocal giant cell lesions, which can range from the more commonly described giant cell granulomas of the mandible to isolated or multifocal intra- or extra-articular tenosynovial giant cell tumors or a combination of all of these lesions.

  16. Multifocal tenosynovial giant cell tumors in a child with Noonan syndrome

    International Nuclear Information System (INIS)

    Meyers, Arthur B.; Awomolo, Agboola O.; Szabo, Sara

    2017-01-01

    Noonan syndrome is a genetic disorder with variable expression of distinctive facial features, webbed neck, chest deformity, short stature, cryptorchidism and congenital heart disease. The association of Noonan syndrome and giant cell granulomas of the mandible is widely reported. However, Noonan syndrome may also be associated with single or multifocal tenosynovial giant cell tumors, also referred to as pigmented villonodular synovitis. We report a child with Noonan syndrome, giant cell granulomas of the mandible and synovial and tenosynovial giant cell tumors involving multiple joints and tendon sheaths who was initially misdiagnosed with juvenile idiopathic arthritis. It is important for radiologists to be aware of the association of Noonan syndrome and multifocal giant cell lesions, which can range from the more commonly described giant cell granulomas of the mandible to isolated or multifocal intra- or extra-articular tenosynovial giant cell tumors or a combination of all of these lesions. (orig.)

  17. Giant Congenital Melanocytic Nevus

    DEFF Research Database (Denmark)

    Rasmussen, Bo Sonnich; Henriksen, Trine Foged; Kølle, Stig-Frederik Trojahn

    2015-01-01

    Giant congenital melanocytic nevi (GCMN) occur in 1:20,000 livebirths and are associated with increased risk of malignant transformation. The treatment of GCMN from 1981 to 2010 in a tertiary referral center was reviewed evaluating the modalities used, cosmetic results, associated complications...

  18. Waking the Sleeping Giant

    NARCIS (Netherlands)

    Ollenburger, Mary H.; Descheemaeker, Katrien; Crane, Todd A.; Sanogo, Ousmane M.; Giller, Ken E.

    2016-01-01

    The World Bank argued that West Africa's Guinea Savannah zone forms part of “Africa's Sleeping Giant,” where increases in agricultural production could be an engine of economic growth, through expansion of cultivated land in sparsely populated areas. The district of Bougouni, in southern Mali,

  19. Isotopic effect giant resonances

    International Nuclear Information System (INIS)

    Buenerd, M.; Lebrun, D.; Martin, P.; Perrin, G.; Saintignon, P. de; Chauvin, J.; Duhamel, G.

    1981-10-01

    The systematics of the excitation energy of the giant dipole, monopole, and quadrupole resonances are shown to exhibit an isotopic effect. For a given element, the excitation energy of the transition decreases faster with the increasing neutron number than the empirical laws fitting the overall data. This effect is discussed in terms of the available models

  20. from the Giant Panda

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... 1College of Life Science, China West Normal University, 44# Yuying Road, 637002, Nanchong, China. 2Zhan Jiang educational ... in Escherichia coli and the RPS28 protein fusioned with the N-terminally GST -tagged protein gave rise ... long Conservation Center of the Giant Panda, Sichuan, China. The.

  1. Giant scrotal elephantiasis.

    Science.gov (United States)

    Kuepper, Daniel

    2005-02-01

    How much can a man carry? Penoscrotal elephantiasis is a debilitating syndrome. This is a case report of a patient with giant genital elephantiasis secondary to long-standing lymphogranuloma venereum infection in Ethiopia. Complete surgical resection of the pathologic tissue and penile reconstruction was undertaken with good cosmetic and functional results.

  2. Giant vesical calculus

    African Journals Online (AJOL)

    Giant vesical calculus. A case report. H. H. LAUBSCHER. Summary. An exceptional case of bladder stone is presented. The case is unusual as regards the size of the stone and the fact that the patient did··not seek medical assistance much earlier, as this was readily avail- able. Furthermore, recovery after removal of the.

  3. Giant abdominal cystic lymphangioma

    International Nuclear Information System (INIS)

    Vazquez, V.; Florencio, I.; Boluda, F.

    1996-01-01

    We present a case of giant abdominal cystic lymphangioma in a 10-year-old boy. Despite numerous consultations with physicians to identify the underlying problem, it had originally been attributed to ascites of unknown cause. We review the characteristics of this lesion and the diagnostic features that aid in differentiating it from ascites

  4. Giant peritoneal loose bodies

    African Journals Online (AJOL)

    2015-03-27

    Mar 27, 2015 ... not be familiar with the entity, can potentially be confused with malignant or parasitic lesions. Familiarity with their characteristic computed tomographic ... preventing unnecessary surgical intervention in an asymptomatic patient.3,4 It is important to differentiate giant peritoneal loose bodies from lesions such ...

  5. Giant Oil Fields - The Highway to Oil: Giant Oil Fields and their Importance for Future Oil Production

    International Nuclear Information System (INIS)

    Robelius, Fredrik

    2007-01-01

    Since the 1950s, oil has been the dominant source of energy in the world. The cheap supply of oil has been the engine for economic growth in the western world. Since future oil demand is expected to increase, the question to what extent future production will be available is important. The belief in a soon peak production of oil is fueled by increasing oil prices. However, the reliability of the oil price as a single parameter can be questioned, as earlier times of high prices have occurred without having anything to do with a lack of oil. Instead, giant oil fields, the largest oil fields in the world, can be used as a parameter. A giant oil field contains at least 500 million barrels of recoverable oil. Only 507, or 1 % of the total number of fields, are giants. Their contribution is striking: over 60 % of the 2005 production and about 65 % of the global ultimate recoverable reserve (URR). However, giant fields are something of the past since a majority of the largest giant fields are over 50 years old and the discovery trend of less giant fields with smaller volumes is clear. A large number of the largest giant fields are found in the countries surrounding the Persian Gulf. The domination of giant fields in global oil production confirms a concept where they govern future production. A model, based on past annual production and URR, has been developed to forecast future production from giant fields. The results, in combination with forecasts on new field developments, heavy oil and oil sand, are used to predict future oil production. In all scenarios, peak oil occurs at about the same time as the giant fields peak. The worst-case scenario sees a peak in 2008 and the best-case scenario, following a 1.4 % demand growth, peaks in 2018

  6. Phenolic Composition and Color of Single Cultivar Young Red Wines Made with Mencia and Alicante-Bouschet Grapes in AOC Valdeorras (Galicia, NW Spain

    Directory of Open Access Journals (Sweden)

    Eugenio Revilla

    2016-07-01

    Full Text Available Single cultivar wines made with two different red grape cultivars from AOC Valdeorras (Galicia, NW Spain, Mencia and Alicante Bouschet, were studied with the aim of determining their color and phenolic composition. Two sets of analyses were made on 30 wine samples of 2014 vintage, after malolactic fermentation took place, to evaluate several physicochemical characteristics from these wines related to color and polyphenols. Several parameters related with color and the general phenolic composition of wines (total phenols index, color intensity, hue, total anthocyans, total anthocyanins, colored anthocyanins, chemical age index, and total tannins were determined by UV-VIS spectrophotometry. Those analyses revealed that Alicante Bouschet wines presented, in general, a higher content of polyphenols and a more intense color than Mencia wines. Using HPLC-DAD, five anthocyanin monoglucosides and nine acylated anthocyanins were identified in both types of wine; each type of wine showed a distinctive anthocyanin fingerprint, as Alicante Bouschet wines contained a higher proportion of cyanidin-derived anthocyanins. Multivariate statistic studies were performed to both datasets to explore relationships among variables and among samples. These studies revealed relationships among several variables considered, and were capable to group the samples in two different classes using principal component analysis (PCA.

  7. THE EXTREMELY RED, YOUNG L DWARF PSO J318.5338–22.8603: A FREE-FLOATING PLANETARY-MASS ANALOG TO DIRECTLY IMAGED YOUNG GAS-GIANT PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Michael C.; Magnier, Eugene A.; Kotson, Michael C.; Aller, Kimberly M.; Burgett, W. S.; Chambers, K. C.; Hodapp, K. W.; Jedicke, R.; Kaiser, N.; Kudritzki, R.-P.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Deacon, Niall R. [Max Planck Institute for Astronomy, Konigstuhl 17, D-69117 Heidelberg (Germany); Allers, Katelyn N. [Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Dupuy, Trent J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Draper, P. W.; Price, P. A. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Metcalfe, N. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2013-11-10

    We have discovered using Pan-STARRS1 an extremely red late-L dwarf, which has (J – K){sub MKO} = 2.78 and (J – K){sub 2MASS} = 2.84, making it the reddest known field dwarf and second only to 2MASS J1207–39b among substellar companions. Near-IR spectroscopy shows a spectral type of L7 ± 1 and reveals a triangular H-band continuum and weak alkali (K I and Na I) lines, hallmarks of low surface gravity. Near-IR astrometry from the Hawaii Infrared Parallax Program gives a distance of 24.6 ± 1.4 pc and indicates a much fainter J-band absolute magnitude than field L dwarfs. The position and kinematics of PSO J318.5–22 point to membership in the β Pic moving group. Evolutionary models give a temperature of 1160{sup +30}{sub -40} K and a mass of 6.5{sup +1.3}{sub -1.0} M {sub Jup}, making PSO J318.5–22 one of the lowest mass free-floating objects in the solar neighborhood. This object adds to the growing list of low-gravity field L dwarfs and is the first to be strongly deficient in methane relative to its estimated temperature. Comparing their spectra suggests that young L dwarfs with similar ages and temperatures can have different spectral signatures of youth. For the two objects with well constrained ages (PSO J318.5–22 and 2MASS J0355+11), we find their temperatures are ≈400 K cooler than field objects of similar spectral type but their luminosities are similar, i.e., these young L dwarfs are very red and unusually cool but not 'underluminous'. Altogether, PSO J318.5–22 is the first free-floating object with the colors, magnitudes, spectrum, luminosity, and mass that overlap the young dusty planets around HR 8799 and 2MASS J1207–39.

  8. Standard globular cluster giant branches in the (MI/V-IO) plane

    International Nuclear Information System (INIS)

    Da Costa, G.S.; Armandroff, T.E.

    1990-01-01

    CCD photometry in the V, I (Cousins) bandpasses is presented for a large number of giants in eight galactic globular clusters. The (V-I) O color of the giant branch accurately ranks clusters in metal abundance, and can accordingly be used to ascertain both metal abundances and abundance dispersions in old stellar populations. A relation is derived that yields the bolometric correction to the I magnitude for red giants as a function of (V-I) O color. With this relation, and the assumption of the LDZ distance scale, the bolometric magnitudes of the brightest red giants in the clusters were determined; good agreement is obtained with the predictions of stellar evolution theory for the luminosity of the He core flash. 63 refs

  9. Effective tuning of the ratio of red to green emission of Ho{sup 3+} ions in single LiLuF{sub 4} microparticle via codoping Ce{sup 3+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Wei, E-mail: gaowei@xupt.edu.cn; Dong, Jun; Liu, Jihong; Yan, Xuewen

    2016-09-15

    Yb{sup 3+}/Ho{sup 3+} codoped LiLuF{sub 4} microparticles have been successfully prepared via a facile hydrothermal method. The crystal phase and morphology of LiLuF{sub 4} microparticles were inspected by x-ray diffraction and scanning electron microscope, respectively. The upconversion emission of single LiLuF{sub 4}: Yb{sup 3+}/Ho{sup 3+} microparticle was carefully studied by a confocal microscopy setup under NIR 980 nm excitation. With the increase of Ce{sup 3+} ion concentrations of 12%, the ratio of red to green emission of the Ho{sup 3+} ions of single LiLuF{sub 4} microparticle was boosted about 17-fold, and the output colors were tuned from green to red, which is due to the two efficient cross-relaxation between Ho{sup 3+} and Ce{sup 3+} ions enhances the red and suppresses the green in the emission processes. To investigate the optical properties of the single microparticle or nanoparticle through the confocal microscopy setup can effectively avoid the influence of surrounding particle or environment, and could provide more precise information for better exploring the emission mechanisms of rare earth ions. The tunable upconversion emission of Ho{sup 3+} in single LiLuF{sub 4} microparticle in this work will have great potential applications in the micro optoelectronic devices and color display applications. - Highlights: • The optical properties of the single LiLuF4: Yb3+/Ho3+/Ce3+ microparticle were studied. • The output colors of single LiLuF4 microparticle were tuned from green to red. • The upconversion mechanisms between Ho3+ and Ce3+ ions were discussed based on emission spectrum.

  10. Einstein Observatory magnitude-limited X-ray survey of late-type giant and supergiant stars

    Science.gov (United States)

    Maggio, A.; Vaiana, G. S.; Haisch, B. M.; Stern, R. A.; Bookbinder, J.

    1990-01-01

    Results are presented of an extensive X-ray survey of 380 giant and supergiant stars of spectral types from F to M, carried out with the Einstein Observatory. It was found that the observed F giants or subgiants (slightly evolved stars with a mass M less than about 2 solar masses) are X-ray emitters at the same level of main-sequence stars of similar spectral type. The G giants show a range of emissions more than 3 orders of magnitude wide; some single G giants exist with X-ray luminosities comparable to RS CVn systems, while some nearby large G giants have upper limits on the X-ray emission below typical solar values. The K giants have an observed X-ray emission level significantly lower than F and F giants. None of the 29 M giants were detected, except for one spectroscopic binary.

  11. Giant cystic craniopharyngiomas

    International Nuclear Information System (INIS)

    Young, S.C.; Zimmerman, R.A.; Nowell, M.A.; Bilaniuk, L.T.; Hackney, D.B.; Grossman, R.I.; Goldberg, H.I.

    1987-01-01

    Three cases of giant cystic craniopharyngiomas with large areas of extension beyond the suprasellar area are presented. The magnetic resonance (MR) appearance in one case is described. These giant tumors had large, multilobulated cysts that comprised the bulk of the tumors. In one case, there was an unusual extension of the large tumor cyst into the lateral ventricle. In two cases, the tumors extended to the level of the foramen magnum. On CT, the cyst contents of these two tumors were hyperdense and became hypodense postoperatively. All three tumors harbored calcifications in the form of clumps in the suprasellar region and rim calcifications around the cysts. None of the tumors exhibited contrast enhancement. A literature review of the radiographic features of craniopharyngiomas is discussed. (orig.)

  12. Giant duodenal ulcers

    Institute of Scientific and Technical Information of China (English)

    Eric Benjamin Newton; Mark R Versland; Thomas E Sepe

    2008-01-01

    Giant duodenal ulcers (GDUs) are a subset of duodenal ulcers that have historically resulted in greater morbidity than usual duodenal ulcers. Until recently,few cases had been successfully treated with medical therapy. However, the widespread use of endoscopy,the introduction of H-2 receptor blockers and proton pump inhibitors, and the improvement in surgical techniques all have revolutionized the diagnosis,treatment and outcome of this condition. Nevertheless,GDUs are still associated with high rates of morbidity,mortality and complications. Thus, surgical evaluation of a patient with a GDU should remain an integral part of patient care. These giant variants, while usually benign, can frequently harbor malignancy. A careful review of the literature highlights the important differences when comparing GDUs to classical peptic ulcers and why they must be thought of differently than their more common counterpart.

  13. Multispin giant magnons

    International Nuclear Information System (INIS)

    Bobev, N. P.; Rashkov, R. C.

    2006-01-01

    We investigate giant magnons from classical rotating strings in two different backgrounds. First we generalize the solution of Hofman and Maldacena and investigate new magnon excitations of a spin chain which are dual to a string on RxS 5 with two nonvanishing angular momenta. Allowing string dynamics along the third angle in the five sphere, we find a dispersion relation that reproduces the Hofman and Maldacena one and the one found by Dorey for the two spin case. In the second part of the paper we generalize the two 'spin' giant magnon to the case of β-deformed AdS 5 xS 5 background. We find agreement between the dispersion relation of the rotating string and the proposed dispersion relation of the magnon bound state on the spin chain

  14. Giant Otters in Peru

    OpenAIRE

    Schenk C.; Staib E.

    1992-01-01

    We are in the second year of fieldwork surveying for Giant Otters in the southeastern rainforest of Peru, in three areas with differing levels of legal protection. While there is some illegal hunting still happening outside the protected areas, the main threat to the otters is badly-conducted tourism. Well-organised tourism can be a promising argument for establishing protected areas like national parks.

  15. Intraoral giant condyloma acuminatum

    Directory of Open Access Journals (Sweden)

    Gupta R

    2001-09-01

    Full Text Available A case of intraoral giant condyloma acuminatum is reported in a 50- year- old Indian. He did not respond to topical application of podophyllin 20% but responded partially to electric cauterisation. Surgical excision was done to get rid of the warty growh completely. Since there were no skin or genital lesions and no history of marital or extramarital sexual contact the lesion was probably acquired from environmental sources. Nonsexual transmission should be considered especially when the lesions are extragenital.

  16. Giant prolactinomas in women

    DEFF Research Database (Denmark)

    Delgrange, Etienne; Raverot, Gerald; Bex, Marie

    2014-01-01

    OBJECTIVE: To characterise distinctive clinical features of giant prolactinomas in women. DESIGN: A multicentre, retrospective case series and literature review. METHODS: We collected data from 15 female patients with a pituitary tumour larger than 4 cm and prolactin levels above 1000 μg/l and id......OBJECTIVE: To characterise distinctive clinical features of giant prolactinomas in women. DESIGN: A multicentre, retrospective case series and literature review. METHODS: We collected data from 15 female patients with a pituitary tumour larger than 4 cm and prolactin levels above 1000 μg....../l and identified 19 similar cases from the literature; a gender-based comparison of the frequency and age distribution was obtained from a literature review. RESULTS: The initial PubMed search using the term 'giant prolactinomas' identified 125 patients (13 women) responding to the inclusion criteria. The female......:male ratio was 1:9. Another six female patients were found by extending the literature search, while our own series added 15 patients. The median age at diagnosis was 44 years in women compared with 35 years in men (Pwomen (n=34), we...

  17. METAL-POOR LITHIUM-RICH GIANTS IN THE RADIAL VELOCITY EXPERIMENT SURVEY

    International Nuclear Information System (INIS)

    Ruchti, Gregory R.; Fulbright, Jon P.; Wyse, Rosemary F. G.; Gilmore, Gerard F.; Grebel, Eva K.; Bienaymé, Olivier; Siebert, Arnaud; Bland-Hawthorn, Joss; Freeman, Ken C.; Gibson, Brad K.; Munari, Ulisse; Navarro, Julio F.; Parker, Quentin A.; Watson, Fred G.; Reid, Warren; Seabroke, George M.; Siviero, Alessandro; Steinmetz, Matthias; Williams, Mary; Zwitter, Tomaz

    2011-01-01

    We report the discovery of eight lithium-rich field giants found in a high-resolution spectroscopic sample of over 700 metal-poor stars ([Fe/H] 7 Li), A(Li) = log (n(Li)/n(H)) + 12, between 2.30 and 3.63, well above the typical upper red giant branch (RGB) limit, A(Li) 7 Be (which burns to 7 Li) is transported to the stellar surface via the Cameron-Fowler mechanism. We discuss and discriminate among several models for the extra mixing that can cause Li production, given the detailed abundances of the Li-rich giants in our sample.

  18. Pulsating red variables

    International Nuclear Information System (INIS)

    Whitelock, P.A.

    1990-01-01

    The observational characteristics of pulsating red variables are reviewed with particular emphasis on the Miras. These variables represent the last stage in the evolution of stars on the Asymptotic Giant Branch (AGB). A large fraction of the IRAS sources in the Bulge are Mira variables and a subset of these are also OH/IR sources. Their periods range up to 720 days, though most are between 360 and 560 days. At a given period those stars with the highest pulsation amplitudes have the highest mass-loss rates; this is interpreted as evidence for a causal connection between mass-loss and pulsation. It is suggested that once an AGB star has become a Mira it will evolve with increasing pulsation amplitude and mass-loss, but with very little change of luminosity or logarithmic period. 26 refs

  19. Membrane fusion between baculovirus budded virus-enveloped particles and giant liposomes generated using a droplet-transfer method for the incorporation of recombinant membrane proteins.

    Science.gov (United States)

    Nishigami, Misako; Mori, Takaaki; Tomita, Masahiro; Takiguchi, Kingo; Tsumoto, Kanta

    2017-07-01

    Giant proteoliposomes are generally useful as artificial cell membranes in biochemical and biophysical studies, and various procedures for their preparation have been reported. We present here a novel preparation technique that involves the combination of i) cell-sized lipid vesicles (giant unilamellar vesicles, GUVs) that are generated using the droplet-transfer method, where lipid monolayer-coated water-in-oil microemulsion droplets interact with oil/water interfaces to form enclosed bilayer vesicles, and ii) budded viruses (BVs) of baculovirus (Autographa californica nucleopolyhedrovirus) that express recombinant transmembrane proteins on their envelopes. GP64, a fusogenic glycoprotein on viral envelopes, is activated by weak acids and is thought to cause membrane fusion with liposomes. Using confocal laser scanning microscopy (CLSM), we observed that the single giant liposomes fused with octadecyl rhodamine B chloride (R18)-labeled wild-type BV envelopes with moderate leakage of entrapped soluble compounds (calcein), and the fusion profile depended on the pH of the exterior solution: membrane fusion occurred at pH ∼4-5. We further demonstrated that recombinant transmembrane proteins, a red fluorescent protein (RFP)-tagged GPCR (corticotropin-releasing hormone receptor 1, CRHR1) and envelope protein GP64 could be partly incorporated into membranes of the individual giant liposomes with a reduction of the pH value, though there were also some immobile fluorescent spots observed on their circumferences. This combination may be useful for preparing giant proteoliposomes containing the desired membranes and inner phases. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The Stability of the Giant Clam Holobiont over Time and during Bleaching Stress

    KAUST Repository

    Pappas, Melissa

    2017-12-01

    The stability of marine photosymbiotic holobionts has major implications for the future of coral reef communities. This study aims to describe the stability of the Red Sea giant clam holobiont over the duration of one year and during induced bleaching stress under laboratory thermal manipulations. Tridacnid clams of the species Tridacna maxima were sampled at three reef locations near the central Saudi coast of the Red Sea. Associated Symbiodinium of Red Sea giant clams have previously been described to be part of only Clade A, which suggests a strong specificity in the clam-algal partnership, but specific types and potential shifting of types within this clade have not been examined for giant clams. The results from this study confirm that tridacnid symbiont types shift over time and the change between three A1 types suggests a biological and functional significance of two undescribed A1 Symbiodinium types. Experimental bleaching shows that Red Sea giant clams, although exposed to rather hot temperatures naturally, will bleach at 34°C after two weeks, and severely bleached clams likely will not recover. During bleaching, Symbiodinium types shift as well, and shift more drastically than seasonal shifts during the year. This shifting may be an evolved characteristic of the giant clam to aid in surviving major changes in the environment. However, more research is needed to determine if these holobionts are capable of keeping up with the global forecast of warming in reef environments.

  1. RED-ML

    DEFF Research Database (Denmark)

    Xiong, Heng; Liu, Dongbing; Li, Qiye

    2017-01-01

    using diverse RNA-seq datasets, we have developed a software tool, RED-ML: RNA Editing Detection based on Machine learning (pronounced as "red ML"). The input to RED-ML can be as simple as a single BAM file, while it can also take advantage of matched genomic variant information when available...... accurately detect novel RNA editing sites without relying on curated RNA editing databases. We have also made this tool freely available via GitHub . We have developed a highly accurate, speedy and general-purpose tool for RNA editing detection using RNA-seq data....... With the availability of RED-ML, it is now possible to conveniently make RNA editing a routine analysis of RNA-seq. We believe this can greatly benefit the RNA editing research community and has profound impact to accelerate our understanding of this intriguing posttranscriptional modification process....

  2. Isoscalar giant resonances

    Energy Technology Data Exchange (ETDEWEB)

    Youngblood, D. H. [Texas A and M Univ., College Station (USA). Cyclotron Inst.; Ikegami, H.; Muraoka, M. [eds.

    1980-01-01

    The current status of the knowledges of giant quadrupole resonance (GQR), low energy octupole resonance (LEOR), and giant monopole resonance (GMR), is described. In the lowest order of multipole resonance, both isoscalar and isovector modes can occur. The characteristics of the GQR in light nuclei are apparent in the experimental result for Mg-24. All of the isoscalar E2 strength are known in Mg-24. The Goldhaber-Teller model is preferred over the Steinwedel-Jensen model for the giant dipole resonance (GDR) transition density. A few interesting and puzzling features have been seen in Pb-208. There is some conflict between inelastic alpha and electron scatterings. About LEOR, the RPA calculation of Liu and Brown was compared to the data for 3/sup -/ strength in Ca-40, Zr-90 and Pb-208. The calculation was employed the residual interaction of the Skyrme type. The agreement in Zr-90 was excellent. The effect of quadrupole deformation on the LEOR in Sm isotopes was large. The inelastic alpha scattering data on Al-27, Ca-40, Ti-48, Ni-58, Zn-64 and 66, Zr-90, Sn-116, 118, 120 and 124, Sm-144, 148 and 154, and Pb-208 were utilized in order to identify the GMR, and the GMR parameters were obtained. The GMR exhausting a large fraction of the sum rule was apparent in the nuclei with mass larger than 90. The splitting of the GDR and the broadening of the GQR in permanently deformed nuclei were established. The splitting of GMR was seen in Sm-154. The studies with heavy ions are also described.

  3. Giant Ulcerative Dermatofibroma

    Directory of Open Access Journals (Sweden)

    Turgut Karlidag

    2013-01-01

    Full Text Available Dermatofibroma is a slowly growing common benign cutaneous tumor characterized by hard papules and nodules. The rarely seen erosions and ulcerations may cause difficulties in the diagnosis. Dermatofibrosarcoma protuberans, which is clinically and histopathologically of malignant character, displays difficulties in the diagnosis since it has similarities with basal cell carcinoma, epidermoid carcinoma, and sarcomas. Head and neck involvement is very rare. In this study, a giant dermatofibroma case, which is histopathologically, ulcerative dermatofibroma, the biggest lesion of the head and neck region and seen rarely in the literature that has characteristics similar to dermatofibrosarcoma protuberans, has been presented.

  4. GIANT PROSTHETIC VALVE THROMBUS

    Directory of Open Access Journals (Sweden)

    Prashanth Kumar

    2015-04-01

    Full Text Available Mechanical prosthetic valves are predisposed to bleeding, thrombosis & thromboembolic complications. Overall incidence of thromboembolic complications is 1% per year who are on oral anticoagulants, whereas bleeding complications incidence is 0.5% to 6.6% per year. 1, 2 Minimization of Scylla of thromboembolic & Charybdis of bleeding complication needs a balancing act of optimal antithrombotic therapy. We are reporting a case of middle aged male patient with prosthetic mitral valve presenting in heart failure. Patient had discontinued anticoagulants, as he had subdural hematoma in the past. He presented to our institute with a giant prosthetic valve thrombus.

  5. A Giant Urethral Calculus.

    Science.gov (United States)

    Sigdel, G; Agarwal, A; Keshaw, B W

    2014-01-01

    Urethral calculi are rare forms of urolithiasis. Majority of the calculi are migratory from urinary bladder or upper urinary tract. Primary urethral calculi usually occur in presence of urethral stricture or diverticulum. In this article we report a case of a giant posterior urethral calculus measuring 7x3x2 cm in a 47 years old male. Patient presented with acute retention of urine which was preceded by burning micturition and dribbling of urine for one week. The calculus was pushed in to the bladder through the cystoscope and was removed by suprapubic cystolithotomy.

  6. Giant paraganglioma in

    Directory of Open Access Journals (Sweden)

    Alka Gupta

    2017-07-01

    Full Text Available Paraganglioma is a rare neuroendocrine catecholamine producing tumour in childhood which arises outside the adrenal medulla. We present a 12 year old girl with giant paraganglioma with severe hypertension and end organ damage. Diagnosis was confirmed with 24 h urinary Vanillymandelic Acid (VMA and CT scan. Preoperative blood pressure was controlled with intravenous nitroprusside, and oral prazosin, amlodepine, labetalol and metoprolol. General anaesthesia with epidural analgesia was given. Intra operative blood pressure rise was managed with infusion of nitriglycerine (NTG, esmolol, nitroprusside and propofol.

  7. GIANT INTRACANALICULAR FIBROADENOMA

    Science.gov (United States)

    Smith, Clyn; Parsons, Robert J.; Bogart, William M.

    1951-01-01

    Five cases of giant intracanalicular fibroadenoma (“cystosarcoma phylloides”) were observed at one hospital in a period of three years. In a search of the literature, additional reports of breast tumors of this kind, not included in previous reviews, were noted. As there is record of 229 cases, it would appear that this rapidly growing benign tumor should be kept in mind in the diagnosis of masses in the breast. If removal is incomplete, there may be recurrence. Simple mastectomy is the treatment of choice. Radical mastectomy should be avoided. ImagesFigure 1Figure 2.Figure 3Figure 4Figure 5 PMID:14848732

  8. Multicolor tuning towards single red-emission band of upconversion nanoparticles for tunable optical component and optical/x-ray imaging agents via Ce"3"+ doping

    International Nuclear Information System (INIS)

    Yi, Zhigao; Zeng, Tianmei; Xu, Yaru; Qian, Chao; Liu, Hongrong; Zeng, Songjun; Lu, Wei; Hao, Jianhua

    2015-01-01

    A simple strategy of Ce"3"+ doping is proposed to realize multicolor tuning and predominant red emission in BaLnF_5:Yb"3"+/Ho"3"+ (Ln"3"+ = Gd"3"+, Y"3"+, Yb"3"+) systems. A tunable upconversion (UC) multicolor output from green/yellow to red can be readily achieved in a fixed Yb"3"+/Ho"3"+ composition by doping Ce"3"+, providing an effective route for multicolor tuning widely used for various optical components. Moreover, compared with Ce"3"+-free UC nanoparticles (UCNPs), a remarkable enhancement of the red-to-green (R/G) ratio is observed by doping 30% Ce"3"+, arising from the two largely promoted cross-relaxation (CR) processes between Ce"3"+ and Ho"3"+. UCNPs with pure red emission are selected as in vivo UC bioimaging agents, demonstrating the merits of deep penetration depth, the absence of autofluorescence and high contrast in small animal bioimaging. Moreover, such fluorescence imaging nanoprobes can also be used as contrast agents for three-dimensional (3D) x-ray bioimaging by taking advantage of the high K-edge values and x-ray absorption coefficients of Ba"2"+, Gd"3"+, and Ce"3"+ in our designed nanoprobes. Thus, the simultaneous realization of multicolor output, highly enhanced R/G ratio, and predominant red emission makes the Ce"3"+-doped UCNPs very useful for widespread applications in optical components and bioimaging. (paper)

  9. Multicolor tuning towards single red-emission band of upconversion nanoparticles for tunable optical component and optical/x-ray imaging agents via Ce(3+) doping.

    Science.gov (United States)

    Yi, Zhigao; Zeng, Tianmei; Xu, Yaru; Lu, Wei; Qian, Chao; Liu, Hongrong; Zeng, Songjun; Hao, Jianhua

    2015-09-25

    A simple strategy of Ce(3+) doping is proposed to realize multicolor tuning and predominant red emission in BaLnF5:Yb(3+)/Ho(3+) (Ln(3+) = Gd(3+), Y(3+), Yb(3+)) systems. A tunable upconversion (UC) multicolor output from green/yellow to red can be readily achieved in a fixed Yb(3+)/Ho(3+) composition by doping Ce(3+), providing an effective route for multicolor tuning widely used for various optical components. Moreover, compared with Ce(3+)-free UC nanoparticles (UCNPs), a remarkable enhancement of the red-to-green (R/G) ratio is observed by doping 30% Ce(3+), arising from the two largely promoted cross-relaxation (CR) processes between Ce(3+) and Ho(3+). UCNPs with pure red emission are selected as in vivo UC bioimaging agents, demonstrating the merits of deep penetration depth, the absence of autofluorescence and high contrast in small animal bioimaging. Moreover, such fluorescence imaging nanoprobes can also be used as contrast agents for three-dimensional (3D) x-ray bioimaging by taking advantage of the high K-edge values and x-ray absorption coefficients of Ba(2+), Gd(3+), and Ce(3+) in our designed nanoprobes. Thus, the simultaneous realization of multicolor output, highly enhanced R/G ratio, and predominant red emission makes the Ce(3+)-doped UCNPs very useful for widespread applications in optical components and bioimaging.

  10. Post-giant evolution of helium stars

    International Nuclear Information System (INIS)

    Schoenberner, D.

    1977-01-01

    Extremely hydrogen deficient stars (helium stars and R Coronae Borealis variables) are considered to be remnants of double shell source stars (of the asymptotic giant branch). The evolution of stars with a condensed C/O-core and a helium envelope is followed numerically from the red giant stage to the white dwarf domain, crossing the regions of R CrB- and helium stars (so far analyzed). They have typically masses M/M(sun) = 0.7 and luminosities log L/L(sun) = 4.1. The time for crossing the helium star domain is some 10 3 years. The corresponding times in the R CrB-region amounts up to several 10 4 years. The lower limit of the death rate of helium stars is estimated to be 4 x 10 -14 pc -3 yr -1 . This value is only a factor of ten lower than the birth rate of all non-DA white dwarfs. It is therefore possible that the helium stars are the precursors of helium rich white dwarfs. As a consequence, a significant fraction of all stars which end their lives as white dwarfs should pass through the helium star phase. (orig.) [de

  11. Giant Impacts on Earth-Like Worlds

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    Earth has experienced a large number of impacts, from the cratering events that may have caused mass extinctions to the enormous impact believed to have formed the Moon. A new study examines whether our planets impact history is typical for Earth-like worlds.N-Body ChallengesTimeline placing the authors simulations in context of the history of our solar system (click for a closer look). [Quintana et al. 2016]The final stages of terrestrial planet formation are thought to be dominated by giant impacts of bodies in the protoplanetary disk. During this stage, protoplanets smash into one another and accrete, greatly influencing the growth, composition, and habitability of the final planets.There are two major challenges when simulating this N-body planet formation. The first is fragmentation: since computational time scales as N^2, simulating lots of bodies that split into many more bodies is very computationally intensive. For this reason, fragmentation is usually ignored; simulations instead assume perfect accretion during collisions.Total number of bodies remaining within the authors simulations over time, with fragmentation included (grey) and ignored (red). Both simulations result in the same final number of bodies, but the ones that include fragmentation take more time to reach that final number. [Quintana et al. 2016]The second challengeis that many-body systems are chaotic, which means its necessary to do a large number of simulations to make statistical statements about outcomes.Adding FragmentationA team of scientists led by Elisa Quintana (NASA NPP Senior Fellow at the Ames Research Center) has recently pushed at these challenges by modeling inner-planet formation using a code that does include fragmentation. The team ran 140 simulations with and 140 without the effects of fragmentation using similar initial conditions to understand how including fragmentation affects the outcome.Quintana and collaborators then used the fragmentation-inclusive simulations to

  12. Allometry indicates giant eyes of giant squid are not exceptional.

    Science.gov (United States)

    Schmitz, Lars; Motani, Ryosuke; Oufiero, Christopher E; Martin, Christopher H; McGee, Matthew D; Gamarra, Ashlee R; Lee, Johanna J; Wainwright, Peter C

    2013-02-18

    The eyes of giant and colossal squid are among the largest eyes in the history of life. It was recently proposed that sperm whale predation is the main driver of eye size evolution in giant squid, on the basis of an optical model that suggested optimal performance in detecting large luminous visual targets such as whales in the deep sea. However, it is poorly understood how the eye size of giant and colossal squid compares to that of other aquatic organisms when scaling effects are considered. We performed a large-scale comparative study that included 87 squid species and 237 species of acanthomorph fish. While squid have larger eyes than most acanthomorphs, a comparison of relative eye size among squid suggests that giant and colossal squid do not have unusually large eyes. After revising constants used in a previous model we found that large eyes perform equally well in detecting point targets and large luminous targets in the deep sea. The eyes of giant and colossal squid do not appear exceptionally large when allometric effects are considered. It is probable that the giant eyes of giant squid result from a phylogenetically conserved developmental pattern manifested in very large animals. Whatever the cause of large eyes, they appear to have several advantages for vision in the reduced light of the deep mesopelagic zone.

  13. Endoscopically removed giant submucosal lipoma

    Directory of Open Access Journals (Sweden)

    Jovanović Ivan

    2007-01-01

    Full Text Available Background. Although uncommon, giant submucosal colon lipomas merit attention as they are often presented with dramatic clinical features such as bleeding, acute bowel obstruction, perforation and sometimes may be mistaken for malignancy. There is a great debate in the literature as to how to treat them. Case report. A patient, 67-year old, was admitted to the Clinic due to a constipation over the last several months, increasing abdominal pain mainly localized in the left lower quadrant accompanied by nausea, vomiting and abdominal distension. Physical examination was unremarkable and the results of the detailed laboratory tests and carcinoembryonic antigen remained within normal limits. Colonoscopy revealed a large 10 cm long, and 4 to 5 cm in diameter, mobile lesion in his sigmoid colon. Conventional endoscopic ultrasound revealed 5 cm hyperechoic lesion of the colonic wall. Twenty MHz mini-probe examination showed that lesion was limited to the submucosa. Since polyp appeared too large for a single transaction, it was removed piecemeal. Once the largest portion of the polyp has been resected, it was relatively easy to place the opened snare loop around portions of the residual polyp. Endoscopic resection was carried out safely without complications. Histological examination revealed the common typical histological features of lipoma elsewhere. The patient remained stable and eventually discharged home. Four weeks later he suffered no recurrent symptoms. Conclusion. Colonic lipomas can be endoscopically removed safely eliminating unnecessary surgery.

  14. Product (RED)

    DEFF Research Database (Denmark)

    Ponte, Stefano

    2011-01-01

    ) and the consumers who buy iconic brand products to help ‘distant others’. While in many other forms of causumerism, labels or certification systems ‘prove’ that a product is just, in RED, aid celebrities provide the proof. From the consumer point of view both labels and celebrities provide a similar simplification...... of complex social, economic, and environmental processes. At the same time, we argue that there are important distinctions as well—labels and certifications are ultimately about improving the conditions of production, whereas RED is about accepting existing production and trade systems and donating......(PRODUCT)RED™ (hereafter RED) is a cobranding initiative launched in 2006 by the aid celebrity Bono to raise money from product sales to support The Global Fund to Fight AIDS, Tuberculosis and Malaria. In this paper we argue that RED is shifting the boundaries of ‘causumerism’ (shopping...

  15. Giant Components in Biased Graph Processes

    OpenAIRE

    Amir, Gideon; Gurel-Gurevich, Ori; Lubetzky, Eyal; Singer, Amit

    2005-01-01

    A random graph process, $\\Gorg[1](n)$, is a sequence of graphs on $n$ vertices which begins with the edgeless graph, and where at each step a single edge is added according to a uniform distribution on the missing edges. It is well known that in such a process a giant component (of linear size) typically emerges after $(1+o(1))\\frac{n}{2}$ edges (a phenomenon known as ``the double jump''), i.e., at time $t=1$ when using a timescale of $n/2$ edges in each step. We consider a generalization of ...

  16. Isoscalar giant resonances in a relativistic model

    International Nuclear Information System (INIS)

    L'Huillier, M.; Nguyen Van Giai.

    1988-07-01

    Isoscalar giant resonances in finite nuclei are studied in a relativistic Random Phase Approximation (RRPA) approach. The model is self-consistent in the sense that one set of coupling constants generates the Dirac-Hartree single-particle spectrum and the residual particle-hole interaction. The RRPA is used to calculate response functions of multipolarity L = 0,2,3, and 4 in light and medium nuclei. It is found that monopole and quadrupole modes exhibit a collective character. The peak energies are overestimated, but not as much as one might think if the bulk properties (compression modulus, effective mass) were the only relevant quantities

  17. Recurrent giant juvenile fibroadenoma

    Directory of Open Access Journals (Sweden)

    Kathryn S. King

    2017-11-01

    Full Text Available Breast masses in children, though rare, present a difficult clinical challenge as they can represent a wide variety of entities from benign fibroadenomas to phyllodes tumors. Rapidly growing or recurrent masses can be particularly concerning to patients, families and physicians alike. Clinical examination and conventional imaging modalities are not efficacious in distinguishing between different tumor types and surgical excision is often recommended for both final diagnosis and for treatment of large or rapidly growing masses. While surgical excision can result in significant long-term deformity of the breast there are some surgical techniques that can be used to limit deformity and/or aid in future reconstruction. Here we present a case of recurrent giant juvenile fibroadenoma with a review of the clinical presentation, diagnostic tools and treatment options.

  18. Hadron excitation of giant resonances

    International Nuclear Information System (INIS)

    Morsch, H.-P.

    1985-01-01

    A review is given on giant resonance studies in heavy nuclei using scattering of different hadronic probes. Concerning isoscalar giant resonances compression modes are discussed with the possibility to obtain more detailed structure information. From detailed studies of α scattering the distribution of isoscalar strengths of multipolarity up to L=6 was obtained. Some recent aspects of heavy ion excitation of collective modes are mentioned. The possibility to study isovector giant resonances in hadron charge exchange reactions is discussed. Finally, a comparison is made between α and 200 MeV proton scattering from which isoscalar and spin-isospin continuum response are extracted. (orig.)

  19. Maxillomandibular giant osteosclerotic lesions

    Directory of Open Access Journals (Sweden)

    Constantino LEDESMA-MONTES

    2018-06-01

    Full Text Available Abstract Giant Osteosclerotic Lesions (GOLs are a group of rarely reported intraosseous lesions. Their precise diagnosis is important since they can be confused with malignant neoplasms. Objective This retrospective study aimed to record and analyze the clinical and radiographic Giant Osteosclerotic Lesions (GOLs detected in the maxillomandibular area of patients attending to our institution. Materials and Methods: Informed consent from the patients was obtained and those cases of 2.5 cm or larger lesions with radiopaque or mixed (radiolucid-radiopaque appearance located in the maxillofacial bones were selected. Assessed parameters were: age, gender, radiographic aspect, shape, borders, size, location and relations to roots. Lesions were classified as radicular, apical, interradicular, interradicular-apical, radicular-apical or located in a previous teeth extraction area. Additionally, several osseous and dental developmental alterations (DDAs were assessed. Results Seventeen radiopacities in 14 patients were found and were located almost exclusively in mandible and were two types: idiopathic osteosclerosis and condensing osteitis. GOLs were more frequent in females, and in the anterior and premolar zones. 94.2% of GOLs were qualified as idiopathic osteosclerosis and one case was condensing osteitis. All studied cases showed different osseous and dental developmental alterations (DDAs. The most common were: Microdontia, hypodontia, pulp stones, macrodontia and variations in the mental foramina. Conclusions GOLs must be differentiated from other radiopaque benign and malignant tumors. Condensing osteitis, was considered an anomalous osseous response induced by a chronic low-grade inflammatory stimulus. For development of idiopathic osteosclerosis, two possible mechanisms could be related. The first is modification of the normal turnover with excessive osseous deposition. The second mechanism will prevent the normal bone resorption, arresting the

  20. Spectral discrimination of giant reed (Arundo donax L.): A seasonal study in riparian areas

    Science.gov (United States)

    Fernandes, Maria Rosário; Aguiar, Francisca C.; Silva, João M. N.; Ferreira, Maria Teresa; Pereira, José M. C.

    2013-06-01

    The giant reed (Arundo donax L.) is amongst the one hundred worst invasive alien species of the world, and it is responsible for biodiversity loss and failure of ecosystem functions in riparian habitats. In this work, field spectroradiometry was used to assess the spectral separability of the giant reed from the adjacent vegetation and from the common reed, a native similar species. The study was conducted at different phenological periods and also for the giant reed stands regenerated after mechanical cutting (giant reed_RAC). A hierarchical procedure using Kruskal-Wallis test followed by Classification and Regression Trees (CART) was used to select the minimum number of optimal bands that discriminate the giant reed from the adjacent vegetation. A new approach was used to identify sets of wavelengths - wavezones - that maximize the spectral separability beyond the minimum number of optimal bands. Jeffries Matusita and Bhattacharya distance were used to evaluate the spectral separability using the minimum optimal bands and in three simulated satellite images, namely Landsat, IKONOS and SPOT. Giant reed was spectrally separable from the adjacent vegetation, both at the vegetative and the senescent period, exception made to the common reed at the vegetative period. The red edge region was repeatedly selected, although the visible region was also important to separate the giant reed from the herbaceous vegetation and the mid infrared region to the discrimination from the woody vegetation. The highest separability was obtained for the giant reed_RAC stands, due to its highly homogeneous, dense and dark-green stands. Results are discussed by relating the phenological, morphological and structural features of the giant reed stands and the adjacent vegetation with their optical traits. Weaknesses and strengths of the giant reed spectral discrimination are highlighted and implications of imagery selection for mapping purposes are argued based on present results.

  1. Giant fibroadenoma of one breast : Immediate bilateral reconstruction

    NARCIS (Netherlands)

    Dolmans, Guido H. C. G.; Hoogbergen, Maarten M.; van Rappard, Julien H. A.

    2007-01-01

    A rare case of giant fibroadenoma of the left breast is presented. We performed a nipple sparing subcutaneous mastectomy of the left breast. Since the patient desired larger breasts, a contralateral augmentation mammaplasty was carried out in a single stage operation. A satisfactory result was

  2. Revealing the microstructure of the giant component in random graph ensembles

    Science.gov (United States)

    Tishby, Ido; Biham, Ofer; Katzav, Eytan; Kühn, Reimer

    2018-04-01

    The microstructure of the giant component of the Erdős-Rényi network and other configuration model networks is analyzed using generating function methods. While configuration model networks are uncorrelated, the giant component exhibits a degree distribution which is different from the overall degree distribution of the network and includes degree-degree correlations of all orders. We present exact analytical results for the degree distributions as well as higher-order degree-degree correlations on the giant components of configuration model networks. We show that the degree-degree correlations are essential for the integrity of the giant component, in the sense that the degree distribution alone cannot guarantee that it will consist of a single connected component. To demonstrate the importance and broad applicability of these results, we apply them to the study of the distribution of shortest path lengths on the giant component, percolation on the giant component, and spectra of sparse matrices defined on the giant component. We show that by using the degree distribution on the giant component one obtains high quality results for these properties, which can be further improved by taking the degree-degree correlations into account. This suggests that many existing methods, currently used for the analysis of the whole network, can be adapted in a straightforward fashion to yield results conditioned on the giant component.

  3. Excitation and photon decay of giant resonances excited by intermediate energy heavy ions

    International Nuclear Information System (INIS)

    Bertrand, F.E.; Beene, J.R.

    1987-01-01

    Inelastic scattering of medium energy heavy ions provides very large cross sections and peak-to-continuum ratios for excitation of giant resonances. For energies above about 50 MeV/nucleon, giant resonances are excited primarily through Coulomb excitation, which is indifferent to isospin, thus providing a good probe for the study of isovector giant resonances. The extremely large cross sections available from heavy ion excitation permit the study of rare decay modes of the giant resonances. In particular, recent measurements have been made of the photon decay of giant resonances following excitation by 22 and 84 MeV/nucleon 17 O projectiles. The singles results at 84 MeV/nucleon yield peak cross sections for the isoscalar giant quadrupole resonance and the isovector giant dipole resonance of approximately 0.8 and 3 barns/sr, respectively. Data on the ground state decay of the isoscalar giant quadrupole and isovector giant dipole resonances are presented and compared with calculations. Decays to low-lying excited states are also discussed. Preliminary results from an experiment to isolate the 208 Pb isovector quadrupole resonance using its gamma decay are presented. 22 refs., 19 figs., 1 tab

  4. Guiding the Giant

    Science.gov (United States)

    1998-08-01

    New ESO Survey Provides Targets for the VLT Giant astronomical telescopes like the ESO Very Large Telescope (VLT) must be used efficiently. Observing time is expensive and there are long waiting lines of excellent research programmes. Thus the work at the telescope must be very well prepared and optimized as much as possible - mistakes should be avoided and no time lost! Astronomers working with the new 8-m class optical/infrared telescopes must base their observations on detailed lists of suitable target objects if they want to perform cutting-edge science. This is particularly true for research programmes that depend on observations of large samples of comparatively rare, distant objects. This type of work requires that extensive catalogues of such objects must be prepared in advance. One such major catalogue - that will serve as a very useful basis for future VLT observations - has just become available from the new ESO Imaging Survey (EIS). The Need for Sky Surveys Astronomers have since long recognized the need to carry out preparatory observations with other telescopes in order to "guide" large telescopes. To this end, surveys of smaller or larger parts of the sky have been performed by wide-field telescopes, paving the way for subsequent work at the limits of the largest available ground-based telescopes. For instance, a complete photographic survey of the sourthern sky (declination work at the 3.6-m telescope at the ESO La Silla observatory. However, while until recently most observational programmes could rely on samples of objects found on photographic plates, this is no longer possible. New image surveys must match the fainter limiting magnitudes reached by the new and larger telescopes. Modern digital, multi-colour, deep imaging surveys have thus become an indispensable complement to the 8-m telescopes. The new generation of imaging surveys will, without doubt, be the backbone of future research and are likely to be as long-lived as their earlier

  5. Current perpendicular to plane giant magnetoresistance and tunneling magnetoresistance treated with unified model

    NARCIS (Netherlands)

    Jonkers, PAE

    2002-01-01

    The conceptual similarity between current perpendicular to plane giant magnetoresistance (CPP-GMR) and tunneling magnetoresistance (TMR) is exploited by utilizing a unified single-particle model accounting for both types of magnetoresistance. By defining structures composed of ferromagnetic,

  6. Asteroseismology of 1523 misclassified red giants using Kepler data

    DEFF Research Database (Denmark)

    Yu, Jie; Huber, Daniel; Bedding, Timothy R.

    2016-01-01

    , using long-cadence light curves. We show that the misclassifications are most likely due to large uncertainties in KIC surface gravities, and do not result from the absence of broad-band colours or from different physical properties such as reddening, spatial distribution, mass or metallicity...

  7. Physical properties of red giants in 47 Tucanae

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, W [Instituto Venezolano de Astronomia, Merida

    1976-07-01

    All published DDO photometry of stars in the metal-rich globular cluster 47 Tucanae has been analysed together. A reddening of E(B-V) = 0.05 and a metal abundance of (Fe/H) = -0.5 were obtained and estimates of the effective temperatures, surface gravities and masses of the ten cluster members derived. Some evidence was found for differences in surface abundance and, possibly, in mass between the stars. The 47 Tucanae data combined with the results for five other globular clusters previously studied by the same technique are discussed in relation to the cyanogen band strengths and the helium abundances of globular cluster stars.

  8. Single and repeated moderate consumption of native or dealcoholized red wine show different effects on antioxidant parameters in blood and DNA strand breaks in peripheral leukocytes in healthy volunteers: a randomized controlled trial [ISRCTN68505294

    Directory of Open Access Journals (Sweden)

    Spengler Ulrich

    2005-11-01

    Full Text Available Abstract Background Red wine (RW is rich in antioxidant polyphenols that might protect from oxidative stress related diseases, such as cardiovascular disease and cancer. Antioxidant effects after single ingestion of RW or dealcoholized RW (DRW have been observed in several studies, but results after regular consumption are contradictory. Thus, we examined if single or repeated consumption of moderate amounts of RW or DRW exert antioxidant activity in vivo. Methods Total phenolic content and concentration of other antioxidants in plasma/serum, total antioxidant capacity (TEAC in plasma as well as DNA strand breaks in peripheral leukocytes were measured in healthy non-smokers A before, 90 and 360 min after ingestion of one glass of RW, DRW or water; B before and after consumption of one glass of RW or DRW daily for 6 weeks. DNA strand breaks (SB were determined by single cell gel electrophoresis (Comet Assay in untreated cells and after induction of oxidative stress ex vivo with H2O2 (300 μM, 20 min. Results Both RW and DRW transiently increased total phenolic content in plasma after single consumption, but only RW lead to a sustained increase if consumed regularly. Plasma antioxidant capacity was not affected by single or regular consumption of RW or DRW. Effects of RW and DRW on DNA SB were conflicting. DNA strand breaks in untreated cells increased after a single dose of RW and DRW, whereas H2O2 induced SB were reduced after DRW. In contrast, regular RW consumption reduced SB in untreated cells but did not affect H2O2 induced SB. Conclusion The results suggest that consumption of both RW and DRW leads to an accumulation of phenolic compounds in plasma without increasing plasma antioxidant capacity. Red wine and DRW seem to affect the occurrence of DNA strand breaks, but this cannot be referred to antioxidant effects.

  9. Rediscovering the Giant Low Surface Brightness Spiral Galaxy Malin 1

    Science.gov (United States)

    Galaz, Gaspar

    2018-01-01

    I summarize the latest discoveries regarding this ramarkable diffuse and giant galaxy, the largest single spiral in the universe so far. I describe how the latest discoveries could have been done easily 20 years ago, but an incredible summation of facts and some astronomical sociology, keeped many of them undisclosed. I present the most conspicuous features of the giant spiral arms of Malin 1, including stellar density, colors, stellar populations and some modeling describing their past evolution to the current state. I conclude with pending issues regarding stellar formation in Malin 1, and the efforts to detect its elusive molecular gas.

  10. Excitation and photon decay of giant multipole resonances

    International Nuclear Information System (INIS)

    Bertrand, F.E.; Beene, J.R.

    1990-01-01

    A brief review of the excitation of giant multipole resonances via Coulomb excitation is given which emphasizes the very large cross sections that can be realized through this reaction for both isoscalar and isovector resonances. Discussion and results where available, are provide for the measurement of the photon decay of one and two phonon giant resonances. It is pointed out throughout the presentation that the use of E1 photons as a ''tag'' provides a means to observe weakly excited resonances that cannot be observed in the singles spectra. 14 refs., 12 figs., 1 tab

  11. GIANT: a computer code for General Interactive ANalysis of Trajectories

    International Nuclear Information System (INIS)

    Jaeger, J.; Lee, M.; Servranckx, R.; Shoaee, H.

    1985-04-01

    Many model-driven diagnostic and correction procedures have been developed at SLAC for the on-line computer controlled operation of SPEAR, PEP, the LINAC, and the Electron Damping Ring. In order to facilitate future applications and enhancements, these procedures are being collected into a single program, GIANT. The program allows interactive diagnosis as well as performance optimization of any beam transport line or circular machine. The test systems for GIANT are those of the SLC project. The organization of this program and some of the recent applications of the procedures will be described in this paper

  12. Collective motion and giant resonances

    International Nuclear Information System (INIS)

    Wilhelmi, Z.; Kicinska-Habior, M.

    1984-01-01

    The report contains 15 papers devoted to problems of giant collective excitations of nuclei, heavy-ion induced reactions and their bearing on various aspects of nuclear structure. In some of them the numerical data are given. (A.S.)

  13. Authenticity control of game meat products--a single method to detect and quantify adulteration of fallow deer (Dama dama), red deer (Cervus elaphus) and sika deer (Cervus nippon) by real-time PCR.

    Science.gov (United States)

    Druml, Barbara; Grandits, Stephanie; Mayer, Walter; Hochegger, Rupert; Cichna-Markl, Margit

    2015-03-01

    This contribution presents a single real-time PCR assay allowing the determination of the deer content (the sum of fallow deer (Dama dama), red deer (Cervus elaphus) and sika deer (Cervus nippon)) in meat products to detect food adulteration. The PCR assay does not show cross-reactivity with 20 animal species and 43 botanical species potentially contained in game meat products. The limit of quantification is 0.5% for fallow deer and red deer and 0.1% for sika deer. The deer content in meat products is determined by relating the concentration obtained with the deer PCR assay to that obtained with a reference system which amplifies mammals and poultry DNA. The analysis of binary meat mixtures with pork, a meat mixture containing equal amounts of fallow deer, red deer and sika deer in pork and a model game sausage showed that the quantification approach is very accurate (systematic error generally <25%). Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Magma Reservoirs Feeding Giant Radiating Dike Swarms: Insights from Venus

    Science.gov (United States)

    Grosfils, E. B.; Ernst, R. E.

    2003-01-01

    Evidence of lateral dike propagation from shallow magma reservoirs is quite common on the terrestrial planets, and examination of the giant radiating dike swarm population on Venus continues to provide new insight into the way these complex magmatic systems form and evolve. For example, it is becoming clear that many swarms are an amalgamation of multiple discrete phases of dike intrusion. This is not surprising in and of itself, as on Earth there is clear evidence that formation of both magma reservoirs and individual giant radiating dikes often involves periodic magma injection. Similarly, giant radiating swarms on Earth can contain temporally discrete subswarms defined on the basis of geometry, crosscutting relationships, and geochemical or paleomagnetic signatures. The Venus data are important, however, because erosion, sedimentation, plate tectonic disruption, etc. on Earth have destroyed most giant radiating dike swarm's source regions, and thus we remain uncertain about the geometry and temporal evolution of the magma sources from which the dikes are fed. Are the reservoirs which feed the dikes large or small, and what are the implications for how the dikes themselves form? Does each subswarm originate from a single, periodically reactivated reservoir, or do subswarms emerge from multiple discrete geographic foci? If the latter, are these discrete foci located at the margins of a single large magma body, or do multiple smaller reservoirs define the character of the magmatic center as a whole? Similarly, does the locus of magmatic activity change with time, or are all the foci active simultaneously? Careful study of giant radiating dike swarms on Venus is yielding the data necessary to address these questions and constrain future modeling efforts. Here, using giant radiating dike swarms from the Nemesis Tessera (V14) and Carson (V43) quadrangles as examples, we illustrate some of the dike swarm focal region diversity observed on Venus and briefly explore some

  15. Kinetic study of the plastoquinone pool availability correlated with H2O2 release in seawater and antioxidant responses in the red alga Kappaphycus alvarezii exposed to single or combined high light, chilling and chemical stresses.

    Science.gov (United States)

    Barros, Marcelo P; Necchi, Orlando; Colepicolo, Pio; Pedersén, Marianne

    2006-11-01

    Under biotic/abiotic stresses, the red alga Kappaphycus alvarezii reportedly releases massive amounts of H(2)O(2) into the surrounding seawater. As an essential redox signal, the role of chloroplast-originated H(2)O(2) in the orchestration of overall antioxidant responses in algal species has thus been questioned. This work purported to study the kinetic decay profiles of the redox-sensitive plastoquinone pool correlated to H(2)O(2) release in seawater, parameters of oxidative lesions and antioxidant enzyme activities in the red alga Kappaphycus alvarezii under the single or combined effects of high light, low temperature, and sub-lethal doses of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB), which are inhibitors of the thylakoid electron transport system. Within 24 h, high light and chilling stresses distinctly affected the availability of the PQ pool for photosynthesis, following Gaussian and exponential kinetic profiles, respectively, whereas combined stimuli were mostly reflected in exponential decays. No significant correlation was found in a comparison of the PQ pool levels after 24 h with either catalase (CAT) or ascorbate peroxidase (APX) activities, although the H(2)O(2) concentration in seawater (R=0.673), total superoxide dismutase activity (R=0.689), and particularly indexes of protein (R=0.869) and lipid oxidation (R=0.864), were moderately correlated. These data suggest that the release of H(2)O(2) from plastids into seawater possibly impaired efficient and immediate responses of pivotal H(2)O(2)-scavenging activities of CAT and APX in the red alga K. alvarezii, culminating in short-term exacerbated levels of protein and lipid oxidation. These facts provided a molecular basis for the recognized limited resistance of the red alga K. alvarezii under unfavorable conditions, especially under chilling stress.

  16. Bringing Low the Giants

    CERN Multimedia

    2001-01-01

    Their work goes on unseen, because they a hundred metres beneath your feet. But while the race against the clock to build the LHC has begun on the surface, teams underground are feverishly engaged to dismantle LEP and its experiments. Four months after the start of dismantling, the technical coordinators of the different experiments discuss the progress of work. Little men attack the giant ALEPH. The barrel and its two endcaps have been removed to the end of the cavern and stripped of their cables. The breaking up of the detector can now begin. At ALEPH, counting rooms removed all in one go Jean-Paul Fabre, technical coordinator at ALEPH:'After making safe the structure, the first step was to remove the wiring and cables. Some 210 cubic metres were brought out. Then the counting rooms all round the detector were taken out. They were brought up from the cavern all in one go, up through the shaft, which is 10 metres wide and 150 metres deep. They made it with 15 centimetres to spare. They have been emptied of...

  17. Giant high occipital encephalocele

    Directory of Open Access Journals (Sweden)

    Agrawal Amit

    2016-03-01

    Full Text Available Encephaloceles are rare embryological mesenchymal developmental anomalies resulting from inappropriate ossification in skull through with herniation of intracranial contents of the sac. Encephaloceles are classified based on location of the osseous defect and contents of sac. Convexity encephalocele with osseous defect in occipital bone is called occipital encephalocele. Giant occipital encephaloceles can be sometimes larger than the size of baby skull itself and they pose a great surgical challenge. Occipital encephaloceles (OE are further classified as high OE when defect is only in occipital bone above the foramen magnum, low OE when involving occipital bone and foramen magnum and occipito-cervical when there involvement of occipital bone, foramen magnum and posterior upper neural arches. Chiari III malformation can be associated with high or low occipital encephaloceles. Pre-operatively, it is essential to know the size of the sac, contents of the sac, relation to the adjacent structures, presence or absence of venous sinuses/vascular structures and osseous defect size. Sometimes it becomes imperative to perform both CT and MRI for the necessary information. Volume rendered CT images can depict the relation of osseous defect to foramen magnum and provide information about upper neural arches which is necessary in classifying these lesions.

  18. Anogenital giant seborrheic keratosis.

    Science.gov (United States)

    Wollina, Uwe; Chokoeva, Anastasiya; Tchernev, Georgi; Heinig, Birgit; Schönlebe, Jacqueline

    2017-08-01

    Seborrheic keratosis (SK) are very common benign epidermal tumors. Giant seborrheic keratosis (GSK) is a rare variant with clinical characteristics, which leads very often to misdiagnosis. A genital site of SK is very unusual clinical manifestation and although the cause is still unknown, current literature data point to a possible pathogenetic role of chronic friction and HPV infection. The rare genital localization makes Buschke-Löwenstein tumor and verrucous carcinoma important differential diagnoses. GSK may also show some clinical features of a melanoacanthoma, which makes cutaneous melanoma as another possible differential diagnosis. The clinical diagnosis of genital GSK is often a very difficult one, because the typical clinical features of GSK disappear and the most common dermoscopic features of GSK are usually not seen in the genital region lesions. The diagnosis of GSK of the anogenital area should be made only and always after the exact histological verification and variety of differential diagnosis should be carefully considered. The treatment of GSK is primary surgically. We present a rare case of GSK with concomitant HPV infection in the anogenital region of 72-year-old patient. Surgical approach was performed with excellent outcome.

  19. An oxygen-rich dust disk surrounding an evolved star in the Red Rectangle

    NARCIS (Netherlands)

    Waters, LBFM; Waelkens, C; van Winckel, H; Molster, FJ; Tielens, AGGM; van Loon, JT; Morris, PW; Cami, J; Bouwman, J; de Koter, A; de Jong, T; de Graauw, T

    1998-01-01

    The Red Rectangle(1) is the prototype of a class of carbon-rich reflection nebulae surrounding low-mass stars in the final stages of evolution. The central star of this nebula has ejected most of its layers (during the red-giant phase), which now form the surrounding cloud, and is rapidly evolving

  20. Excitation of giant resonances in heavy ion collisions

    International Nuclear Information System (INIS)

    Kuehn, W.

    1991-01-01

    Introduction: What are Giant Resonances? General Features of Giant Resonances, Macroscopic Description and Classification, Basic Excitation Mechanisms, Decay Modes, Giant Resonances Built on Excited States, Relativistic Coulomb Excitation of Giant Resonances, Experimental Situation. (orig.)

  1. Formation of giant planets

    International Nuclear Information System (INIS)

    Perri, F.

    1975-01-01

    When a planetary core composed of condensed matter is accumulated in the primitive solar nebula, the gas of the nebula becomes gravitationally concentrated as an envelope surrounding the planetary core. Models of such gaseous envelopes have been constructed subject to the assumption that the gas everywhere is on the same adiabat as that in the surrounding nebula. The gaseous envelope extends from the surface of the core to the distance at which the gravitational attraction of core plus envelope becomes equal to the gradient of the gravitational potential in the solar nebula; at this point the pressure and temperature of the gas in the envelope are required to attain the background values characteristic of the solar nebula. In general, as the mass of the condensed core increases, increasing amounts of gas became concentrated in the envelope, and these envelopes are stable against hydrodynamic instabilities. However, the core mass then goes through a maximum and starts to decrease. In most of the models tested the envelopes were hydrodynamically unstable beyond the peak in the core mass. An unstable situation was always created if it was insisted that the core mass contain a larger amount of matter than given by these solutions. For an initial adiabat characterized by a temperature of 450 0 K and a pressure of 5 x 10 -6 atmospheres, the maximum core mass at which instability occurs is approximately 115 earth masses. It is concluded that the giant planets obtained their large amounts of hydrogen and helium by a hydrodynamic collapse process in the solar nebula only after the nebula had been subjected to a considerable period of cooling

  2. Mining a database of single amplified genomes from Red Sea brine pool extremophiles-improving reliability of gene function prediction using a profile and pattern matching algorithm (PPMA).

    KAUST Repository

    Grö tzinger, Stefan W.; Alam, Intikhab; Ba Alawi, Wail; Bajic, Vladimir B.; Stingl, Ulrich; Eppinger, Jö rg

    2014-01-01

    Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs) and poor homology of novel extremophile's genomes pose significant

  3. On Landau Vlasov simulations of giant resonances

    International Nuclear Information System (INIS)

    Pi, M.; Schuck, P.; Suraud, E.; Gregoire, C.; Remaud, B.; Sebille, F.

    1987-05-01

    We present VUU calculations of giant resonances obtained in energetic heavy ion collisions. Also is considered the case of the giant dipole in 40 Ca and the possibility of studying the effects of rotation on such collective modes

  4. Giant lobelias exemplify convergent evolution

    Directory of Open Access Journals (Sweden)

    Givnish Thomas J

    2010-01-01

    Full Text Available Abstract Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution.

  5. CMB lensing and giant rings

    Energy Technology Data Exchange (ETDEWEB)

    Rathaus, Ben; Itzhaki, Nissan, E-mail: nitzhaki@post.tau.ac.il, E-mail: ben.rathaus@gmail.com [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Ramat-Aviv, 69978 (Israel)

    2012-05-01

    We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

  6. Imaging of giant pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Majos, C.; Coll, S.; Aguilera, C.; Pons, L.C. [Bellvitge Univ., Barcelona (Spain). Inst. de Diagnostice per la Imatge; Acebes, J.J. [Department of Neurosurgery, Ciutat Sanitaria i Universitaria de Bellvitge, L`Hospitalet de Llobregat, Barcelona (Spain)

    1998-10-01

    We present five proven giant pituitary adenomas studied by CT and MRI, and review the clinical and imaging findings. Our aim was to examine the radiologic appearances and to search for criteria useful in distinguishing these tumors from other sellar and suprasellar tumours, mainly craniopharyngioma. The main differences from small adenomas were high prevalence of macrocysts, a more invasive behaviour and a clinical picture dominated by mass effect rather than endocrine disturbance. Factors supporting the diagnosis of pituitary adenoma in a giant intra- and suprasellar mass include: infrasellar extension, absence of calcification and presence of low-signal cysts on T1-weighted images. (orig.) (orig.) With 4 figs., 2 tabs., 9 refs.

  7. [Giant intradiploic infratentorial epidermoid cyst].

    Science.gov (United States)

    Alberione, F; Caire, F; Fischer-Lokou, D; Gueye, M; Moreau, J J

    2007-10-01

    Epidermoid cysts are benign, uncommon lesions (1% of all intracranial tumors). Their localization is intradiploic in 25% of cases, and exceptionally subtentorial. We report here a rare case of giant intradiploic infratentorial epidermoid cyst. A 74-year old patient presented with recent diplopia and sindrome cerebellar. CT scan and MR imaging revealed a giant osteolytic extradural lesion of the posterior fossa (5.2 cm x 3.8 cm) with a small area of peripheral enhancement after contrast injection. Retrosigmoid suboccipital craniectomy allowed a satisfactory removal of the tumor, followed by an acrylic cranioplasty. The outcome was good. Neuropathological examination confirmed an epidermoid cyst. We review the literature and discuss our case.

  8. Percolation with multiple giant clusters

    International Nuclear Information System (INIS)

    Ben-Naim, E; Krapivsky, P L

    2005-01-01

    We study mean-field percolation with freezing. Specifically, we consider cluster formation via two competing processes: irreversible aggregation and freezing. We find that when the freezing rate exceeds a certain threshold, the percolation transition is suppressed. Below this threshold, the system undergoes a series of percolation transitions with multiple giant clusters ('gels') formed. Giant clusters are not self-averaging as their total number and their sizes fluctuate from realization to realization. The size distribution F k , of frozen clusters of size k, has a universal tail, F k ∼ k -3 . We propose freezing as a practical mechanism for controlling the gel size. (letter to the editor)

  9. Statistical decay of giant resonances

    International Nuclear Information System (INIS)

    Dias, H.; Teruya, N.; Wolynec, E.

    1986-01-01

    Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the resutls on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monople giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excelent agreement with recent experimental data, showing that the decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

  10. Giant resonances: reaction theory approach

    International Nuclear Information System (INIS)

    Toledo Piza, A.F.R. de; Foglia, G.A.

    1989-09-01

    The study of giant resonances through the use of reaction theory approach is presented and discussed. Measurements of cross-sections to the many available decay channels following excitation of giant multipole resonances (GMR) led one to view these phenomena as complicated dynamical syndromes so that theoretical requirements for their study must be extended beyond the traditional bounds of nuclear structure models. The spectra of decay products following GMR excitation in heavy nuclei are well described by statistical model (Hauser-Feshback, HF) predictions indicated that spreading of the collective modes plays a major role in shaping exclusive cross-sections. (A.C.A.S.) [pt

  11. Statistical decay of giant resonances

    International Nuclear Information System (INIS)

    Dias, H.; Teruya, N.; Wolynec, E.

    1986-02-01

    Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the results on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monopole giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excellent agreement with recent experimental data, showing that decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

  12. Migration of accreting giant planets

    Science.gov (United States)

    Robert, C.; Crida, A.; Lega, E.; Méheut, H.

    2017-09-01

    Giant planets forming in protoplanetary disks migrate relative to their host star. By repelling the gas in their vicinity, they form gaps in the disk's structure. If they are effectively locked in their gap, it follows that their migration rate is governed by the accretion of the disk itself onto the star, in a so-called type II fashion. Recent results showed however that a locking mechanism was still lacking, and was required to understand how giant planets may survive their disk. We propose that planetary accretion may play this part, and help reach this slow migration regime.

  13. Giant serpentine intracranial aneurysm: a case report

    International Nuclear Information System (INIS)

    Park, Jae Seong; Lee, Myeong Sub; Kim, Myung Soon; Kim, Dong Jin; Park, Joong Wha; Whang, Kum

    2001-01-01

    The authors present a case of giant serpentine aneurysm (a partially thrombosed aneurysm containing tortuous vascular channels with a separate entrance and outflow pathway). Giant serpentine aneurysms form a subgroup of giant intracranial aneurysms, distinct from saccular and fusiform varieties, and in this case, too, the clinical presentation and radiographic features of CT, MR imaging and angiography were distinct

  14. Giant multipole resonances: perspectives after ten years

    International Nuclear Information System (INIS)

    Bertrand, F.E.

    1980-01-01

    Nearly ten years ago evidence was published for the first of the so-called giant multipole resonances, the giant quadrupole resonance. During the ensuing years research in this field has spread to many nuclear physics laboratories throughout the world. The present status of electric giant multipole resonances is reviewed. 24 figures, 1 table

  15. Giant pulses of pulsar radio emission

    OpenAIRE

    Kuzmin, A. D.

    2007-01-01

    Review report of giant pulses of pulsar radio emission, based on our detections of four new pulsars with giant pulses, and the comparative analysis of the previously known pulsars with giant pulses, including the Crab pulsar and millisecond pulsar PSR B1937+21.

  16. The Stability of the Giant Clam Holobiont over Time and during Bleaching Stress

    KAUST Repository

    Pappas, Melissa

    2017-01-01

    Experimental bleaching shows that Red Sea giant clams, although exposed to rather hot temperatures naturally, will bleach at 34°C after two weeks, and severely bleached clams likely will not recover. During bleaching, Symbiodinium types shift as well, and shift more drastically than seasonal shifts during the year. This shifting may be an evolved characteristic of the giant clam to aid in surviving major changes in the environment. However, more research is needed to determine if these holobionts are capable of keeping up with the global forecast of warming in reef environments.

  17. Safety and efficacy of allogeneic umbilical cord red blood cell transfusion for children with severe anaemia in a Kenyan hospital: an open-label single-arm trial

    Science.gov (United States)

    Hassall, Oliver W; Thitiri, Johnstone; Fegan, Greg; Hamid, Fauzat; Mwarumba, Salim; Denje, Douglas; Wambua, Kongo; Mandaliya, Kishor; Maitland, Kathryn; Bates, Imelda

    2015-01-01

    Summary Background In sub-Saharan Africa, children are frequently admitted with severe anaemia needing an urgent blood transfusion, but blood is often unavailable. When conventional blood supplies are inadequate, allogeneic umbilical cord blood could be a feasible alternative. The aim of this study was to assess the safety and efficacy of cord blood transfusion in children with severe anaemia. Methods Between June 26, 2007, and May 20, 2008, 413 children needing an urgent blood transfusion were admitted to Kilifi District Hospital in Kenya. Of these, 87 children were eligible for our study—ie, younger than 12 years, no signs of critical illness, and haemoglobin 100 g/L or lower (if aged 3 months or younger) or 40 g/L or lower (if older than 3 months). Cord blood was donated at Coast Provincial General Hospital, Mombasa, and screened for transfusion-transmitted infections and bacterial contamination. Red blood cells were stored vertically at 2–6°C to enable sedimentation. After transfusion, children were monitored closely for adverse events and followed up for 28 days. The primary outcome measure was the frequency and nature of adverse reactions associated with the transfusion. Secondary outcomes were the changes in haemoglobin concentrations 24 h and 28 days after transfusion, compared with pretransfusion levels. This trial is registered on ISRCTN.com, number ISRCTN66687527. Findings Of the 87 children eligible for the study, cord blood was unavailable for 24, six caregivers declined consent, and two children were withdrawn before transfusion. Therefore, 55 children received umbilical cord red blood cells from 74 donations. Ten (18%) children had ten serious adverse events and 43 (78%) had 94 adverse events; the most frequent adverse events were anaemia (n=14), weight loss (n=12), and vomiting (n=10). An independent expert panel judged none of these adverse events to be probably or certainly caused by the cord blood transfusion (one-sided 97·5% CI 0–6·5

  18. Safety and efficacy of allogeneic umbilical cord red blood cell transfusion for children with severe anaemia in a Kenyan hospital: an open-label single-arm trial.

    Science.gov (United States)

    Hassall, Oliver W; Thitiri, Johnstone; Fegan, Greg; Hamid, Fauzat; Mwarumba, Salim; Denje, Douglas; Wambua, Kongo; Mandaliya, Kishor; Maitland, Kathryn; Bates, Imelda

    2015-03-01

    In sub-Saharan Africa, children are frequently admitted with severe anaemia needing an urgent blood transfusion, but blood is often unavailable. When conventional blood supplies are inadequate, allogeneic umbilical cord blood could be a feasible alternative. The aim of this study was to assess the safety and efficacy of cord blood transfusion in children with severe anaemia. Between June 26, 2007, and May 20, 2008, 413 children needing an urgent blood transfusion were admitted to Kilifi District Hospital in Kenya. Of these, 87 children were eligible for our study--ie, younger than 12 years, no signs of critical illness, and haemoglobin 100 g/L or lower (if aged 3 months or younger) or 40 g/L or lower (if older than 3 months). Cord blood was donated at Coast Provincial General Hospital, Mombasa, and screened for transfusion-transmitted infections and bacterial contamination. Red blood cells were stored vertically at 2-6°C to enable sedimentation. After transfusion, children were monitored closely for adverse events and followed up for 28 days. The primary outcome measure was the frequency and nature of adverse reactions associated with the transfusion. Secondary outcomes were the changes in haemoglobin concentrations 24 h and 28 days after transfusion, compared with pretransfusion levels. This trial is registered on ISRCTN.com, number ISRCTN66687527. Of the 87 children eligible for the study, cord blood was unavailable for 24, six caregivers declined consent, and two children were withdrawn before transfusion. Therefore, 55 children received umbilical cord red blood cells from 74 donations. Ten (18%) children had ten serious adverse events and 43 (78%) had 94 adverse events; the most frequent adverse events were anaemia (n=14), weight loss (n=12), and vomiting (n=10). An independent expert panel judged none of these adverse events to be probably or certainly caused by the cord blood transfusion (one-sided 97·5% CI 0-6·5). Haemoglobin increased by a median of 26 g

  19. CHROMOSPHERIC MODELS AND THE OXYGEN ABUNDANCE IN GIANT STARS

    Energy Technology Data Exchange (ETDEWEB)

    Dupree, A. K.; Avrett, E. H.; Kurucz, R. L., E-mail: dupree@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2016-04-10

    Realistic stellar atmospheric models of two typical metal-poor giant stars in Omega Centauri, which include a chromosphere (CHR), influence the formation of optical lines of O i: the forbidden lines (λ6300, λ6363) and the infrared triplet (λλ7771−7775). One-dimensional semi-empirical non-local thermodynamic equilibrium (LTE) models are constructed based on observed Balmer lines. A full non-LTE formulation is applied for evaluating the line strengths of O i, including photoionization by the Lyman continuum and photoexcitation by Lyα and Lyβ. Chromospheric models (CHR) yield forbidden oxygen transitions that are stronger than those in radiative/convective equilibrium (RCE) models. The triplet oxygen lines from high levels also appear stronger than those produced in an RCE model. The inferred oxygen abundance from realistic CHR models for these two stars is decreased by factors of ∼3 as compared to values derived from RCE models. A lower oxygen abundance suggests that intermediate-mass AGB stars contribute to the observed abundance pattern in globular clusters. A change in the oxygen abundance of metal-poor field giants could affect models of deep mixing episodes on the red giant branch. Changes in the oxygen abundance can impact other abundance determinations that are critical to astrophysics, including chemical tagging techniques and galactic chemical evolution.

  20. Calculating the Contribution of Zooxanthellae to Giant Clams Respiration Energy Requirements

    OpenAIRE

    Ambariyanto

    2002-01-01

    Giant clams (Tridacnidae) are known to live in association with photosynthetic single cell dinoflagellate algae commonly called zooxanthellae. These algae which can be found in the mantle of the clams are capable of transferring part of their photosynthates which become an important source of energy to the host ( apart from filter feeding activity). In order to understand the basic biological processes of the giant clams , the contribution of zooxanthellae to the clam's energy requirement nee...

  1. Skin metastasis from conventional giant cell tumor of bone: conceptual significance

    International Nuclear Information System (INIS)

    Tyler, W.; Barrett, T.; Frassica, F.; McCarthy, E.

    2002-01-01

    A conventional giant cell tumor of the proximal femur recurred twice locally and developed pulmonary nodules. The lung lesions were felt to be an example of ''benign'' metastases. Eight months after the initial presentation, the patient developed a single skin nodule on the contralateral leg. Histologic features of the skin nodule showed conventional giant cell tumor identical to the bone lesion. This nodule is a manifestation of arterial metastasis typical of any malignant tumor and seemingly contradicts the concept of ''benign '' metastasis. (orig.)

  2. Giant lipomas of the hand

    Directory of Open Access Journals (Sweden)

    Gokce Yildiran

    2015-04-01

    Conclusion: Giant lipomas of the hand are very rare and may cause compressions and other complications. Thus, they require a careful preoperative evaluation in order to make a proper differential diagnosis. [Hand Microsurg 2015; 4(1.000: 8-11

  3. Management of giant paraesophageal hernia.

    Science.gov (United States)

    Awais, O; Luketich, J D

    2009-04-01

    Management of giant paraesophageal hernia remains one of the most difficult challenges faced by surgeons treating complex benign esophageal disorders. These large hernias are acquired disorders; therefore, they invariably present in elderly patients. The dilemma that surgeons faced in the open surgical era was the risk of open surgery in this elderly, sick patient population versus the life threatening catastrophic complications, nearly 30% in some series, observed with medical management. During the 1990s, it was clearly recognized that laparoscopic surgery led to decreased morbidity with a quicker recovery. This has lead to a 6-fold increase in the surgical management of giant paraesophageal hernias over the last decade compared to a period of five decades of open surgery; however, this has not necessarily translated into better outcomes. One of the major issues with giant paraesophageal hernias is recognizing short esophagus and performing a lengthening procedure, if needed. Open series which report liberal use of Collis gastroplasty leading to a tension-free intraabdominal fundoplication have shown the best anatomic and clinical outcomes. As we duplicate the open experience laparoscopically, the principle of identifying a shortened esophagus and constructing a neo-esophagus must be honored for the success of the operation. The benefits of laparoscopy are obvious but should not come at the cost of a lesser operation. This review will illustrate that laparoscopic repair of giant paraesophageal hernia at experienced centers can be performed safely with similar outcomes to open series when the fundamental principles of the operation are maintained.

  4. A Giant or a Dwarf?

    DEFF Research Database (Denmark)

    Schmid, Herman

    2005-01-01

    EU may appear to be a giant when it can act on behalf of a united Europe, but usually it is hampered by conflicting member state interests. The EU economic and administrative resources for foreign and trade policy are quite small (on level with one of its major member states) and the hopes in many...

  5. Giant resonances on excited states

    International Nuclear Information System (INIS)

    Besold, W.; Reinhard, P.G.; Toepffer, C.

    1984-01-01

    We derive modified RPA equations for small vibrations about excited states. The temperature dependence of collective excitations is examined. The formalism is applied to the ground state and the first excited state of 90 Zr in order to confirm a hypothesis which states that not only the ground state but every excited state of a nucleus has a giant resonance built upon it. (orig.)

  6. Michigan has a sleeping giant

    CERN Multimedia

    Brock, Raymond; Nichols, Sue

    2007-01-01

    "That giant is 750 miles of fiber optic cable that lassoes its three biggest research universities and Van Andel Institute to the future. Its mission: to uncover the nature of the Big Bang by connecton U.S. physicists to their huge experiment ATLAS in Geneva.." (4 pages)

  7. HST images of dark giants as dark matter: Part.I The black cocoon stars of Carina Nebula region

    International Nuclear Information System (INIS)

    Celis, S.L.

    2001-01-01

    In an evolutionary scenario, the existence of isolated dark giant objects known as Post M latest spectral type stars (1) (or black cocoon stars) are in the last stage of their life and, as extremely advanced old age objects, they cease to be stars. The photographic images of Carina nebula taken by the Hubble Space Telescope (HST) have been used to detect the post M-Iatest stars as dark silhouettes. The luminosity attenuation equation of M late stars (1), A = αS 3 , points out the baryonic dark matter envelopes the oldest red giants that produce earlier dark giants. This equation says that when the red giant star finishes to produce baryonic dark matter, the central star is extinguishing and transforms into dark giants and dusty globules that disperse cool gaseous matter into the interstellar space. These old dark objects have a size from 400 to 600 astronomical units (AU). The advanced dark giants, the dusty dark giants, might not contain a star within the molecular cloud that envelops it. In this case, the dark giants might produce the smaller and less massive dark globules of the Thackeray's globules type (less than 4 solar masses) where, Reupurth et al. (2) found that these globules are now in an advanced stage of disintegration and they found no evidence of star formation in any of these objects. The high-resolution of the Hubble images allows: The observation of isolated dark giants, dusty globules with central dark giants, the observation of partial eclipses or transiting of giant stars and the estimation of linear and angular diameters (ionised cocoons) of giant stellar objects. The dark giants of the image are identified them as objects with observed angular diameter. The large quantity of dark giants in a small sector of the sky suggests that they are densely populated (population stars III) and ubiquitous in the galactic disc. They can be located in isolated form or associated in dense Conglomerations of dark giants. At the same time, conglomerates of

  8. Giant hydronephrosis mimicking progressive malignancy

    Science.gov (United States)

    Schrader, Andres Jan; Anderer, Georgia; von Knobloch, Rolf; Heidenreich, Axel; Hofmann, Rainer

    2003-01-01

    Background Cases of giant hydronephroses are rare and usually contain no more than 1–2 litres of fluid in the collecting system. We report a remarkable case of giant hydronephrosis mimicking a progressive malignant abdominal tumour. Case presentation A 78-year-old cachectic woman presented with an enormous abdominal tumour, which, according to the patient, had slowly increased in diameter. Medical history was unremarkable except for a hysterectomy >30 years before. A CT scan revealed a giant cystic tumour filling almost the entire abdominal cavity. It was analysed by two independent radiologists who suspected a tumour originating from the right kidney and additionally a cystic ovarian neoplasm. Subsequently, a diagnostic and therapeutic laparotomy was performed: the tumour presented as a cystic, 35 × 30 × 25 cm expansive structure adhesive to adjacent organs without definite signs of invasive growth. The right renal hilar vessels could finally be identified at its basis. After extirpation another tumourous structure emerged in the pelvis originating from the genital organs and was also resected. The histopathological examination revealed a >15 kg hydronephrotic right kidney, lacking hardly any residual renal cortex parenchyma. The second specimen was identified as an ovary with regressive changes and a large partially calcified cyst. There was no evidence of malignant growth. Conclusion Although both clinical symptoms and the enormous size of the tumour indicated malignant growth, it turned out to be a giant hydronephrosis. Presumably, a chronic obstruction of the distal ureter had caused this extraordinary hydronephrosis. As demonstrated in our case, an accurate diagnosis of giant hydronephrosis remains challenging due to the atrophy of the renal parenchyma associated with chronic obstruction. Therefore, any abdominal cystic mass even in the absence of other evident pathologies should include the differential diagnosis of a possible hydronephrosis. Diagnostic

  9. Giant piezoelectricity on Si for hyperactive MEMS.

    Science.gov (United States)

    Baek, S H; Park, J; Kim, D M; Aksyuk, V A; Das, R R; Bu, S D; Felker, D A; Lettieri, J; Vaithyanathan, V; Bharadwaja, S S N; Bassiri-Gharb, N; Chen, Y B; Sun, H P; Folkman, C M; Jang, H W; Kreft, D J; Streiffer, S K; Ramesh, R; Pan, X Q; Trolier-McKinstry, S; Schlom, D G; Rzchowski, M S; Blick, R H; Eom, C B

    2011-11-18

    Microelectromechanical systems (MEMS) incorporating active piezoelectric layers offer integrated actuation, sensing, and transduction. The broad implementation of such active MEMS has long been constrained by the inability to integrate materials with giant piezoelectric response, such as Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PMN-PT). We synthesized high-quality PMN-PT epitaxial thin films on vicinal (001) Si wafers with the use of an epitaxial (001) SrTiO(3) template layer with superior piezoelectric coefficients (e(31,f) = -27 ± 3 coulombs per square meter) and figures of merit for piezoelectric energy-harvesting systems. We have incorporated these heterostructures into microcantilevers that are actuated with extremely low drive voltage due to thin-film piezoelectric properties that rival bulk PMN-PT single crystals. These epitaxial heterostructures exhibit very large electromechanical coupling for ultrasound medical imaging, microfluidic control, mechanical sensing, and energy harvesting.

  10. Giant Pulse Studies of Ordinary and Recycled Pulsars with NICER

    Science.gov (United States)

    Lewandowska, Natalia; Arzoumanian, Zaven; Gendreau, Keith C.; Enoto, Teruaki; Harding, Alice; Lommen, Andrea; Ray, Paul S.; Deneva, Julia; Kerr, Matthew; Ransom, Scott M.; NICER Team

    2018-01-01

    Radio Giant Pulses are one of the earliest discovered form of anomalous single pulse emission from pulsars. Known for their non-periodical occurrence, restriction to certain phase ranges, power-law intensity distributions, pulse widths ranging from microseconds to nanoseconds and very high brightness temperatures, they stand out as an individual form of pulsar radio emission.Discovered originally in the case of the Crab pulsar, several other pulsars have been observed to emit radio giant pulses, the most promising being the recycled pulsar PSR B1937+21 and also the Vela pulsar.Although radio giant pulses are apparently the result of a coherent emission mechanism, recent studies of the Crab pulsar led to the discovery of an additional incoherent component at optical wavelengths. No such component has been identified for recycled pulsars, or Vela yet.To provide constraints on possible emission regions in their magnetospheres and to search for differences between giant pulses from ordinary and recycled pulsars, we present the progress of the correlation study of PSR B1937+21 and the Vela pulsar carried out with NICER and several radio observatories.

  11. Quantized TDHF for isoscalar giant quadrupole resonances in spherical nuclei

    International Nuclear Information System (INIS)

    Drozdz, S.; Okolowicz, J.; Ploszajczak, M.; Caurier, E.

    1988-01-01

    The time-dependent Hartree-Fock theory supplemented with the regularity and single-valuedness quantization condition for the gauge invariant component of the wavefunction is applied to the description of the centroid energy and escape width of isoscalar giant quadrupole resonances in 16 O, 40 Ca and 110 Zr. Calculations are performed using the Skyrme SIII effective interaction. An important role of the finite oscillation amplitude in the mean-field dynamics is emphasized. (orig.)

  12. Near infra-red spectroscopy quantitative modelling of bivalve protein, lipid and glycogen composition using single-species versus multi-species calibration and validation sets

    Science.gov (United States)

    Bartlett, Jill K.; Maher, William A.; Purss, Matthew B. J.

    2018-03-01

    Near infrared spectroscopy (NIRS) quantitative modelling was used to measure the protein, lipid and glycogen composition of five marine bivalve species (Saccostrea glomerata, Ostrea angasi, Crassostrea gigas, Mytilus galloprovincialis and Anadara trapezia) from multiple locations and seasons. Predictive models were produced for each component using individual species and aggregated sample populations for the three oyster species (S. glomerata, O. angasi and C. gigas) and for all five bivalve species. Whole animal tissues were freeze dried, ground to > 20 μm and scanned by NIRS. Protein, lipid and glycogen composition were determined by traditional chemical analyses and calibration models developed to allow rapid NIRS-measurement of these components in the five bivalve species. Calibration modelling was performed using wavelet selection, genetic algorithms and partial least squares analysis. Model quality was assessed using RPIQ and RMESP. For protein composition, single species model results had RPIQ values between 2.4 and 3.5 and RMSEP between 8.6 and 18%, the three oyster model had an RPIQ of 2.6 and an RMSEP of 10.8% and the five bivalve species had an RPIQ of 3.6 and RMSEP of 8.7% respectively. For lipid composition, single species models achieved RPIQ values between 2.9 and 5.3 with RMSEP between 9.1 and 11.2%, the oyster model had an RPIQ of 3.6 and RMSEP of 6.8 and the five bivalve model had an RPIQ of 5.2 and RMSEP of 6.8% respectively. For glycogen composition, the single species models had RPIQs between 3.8 and 18.9 with RMSEP between 3.5 and 9.2%, the oyster model had an RPIQ of 5.5 and RMSEP of 7.1% and the five bivalve model had an RPIQ of 4 and RMSEP of 7.6% respectively. Comparison between individual species models and aggregated models for three oyster species and five bivalve species for each component indicate that aggregating data from like species produces high quality models with robust and reliable quantitative application. The benefit of

  13. Pharmacodynamics of alfaxalone after single-dose intramuscular administration in red-eared sliders (Trachemys scripta elegans): a comparison of two different doses at two different ambient temperatures.

    Science.gov (United States)

    Shepard, Molly K; Divers, Stephen; Braun, Christina; Hofmeister, Erik H

    2013-11-01

    This study compares the pharmacodynamics of two different doses of alfaxalone administered intramuscularly (IM) to red-eared sliders at two ambient temperatures. Prospective blinded crossover experimental study. Nine adult female sliders (Trachemys scripta elegans). Following a 2-week acclimation at 22-25 °C, nine sliders were randomly assigned to receive alfaxalone, 10 mg kg(-1) (W10), or 20 mg kg(-1) (W20) IM. Each turtle received each dose, with a minimum 7-day washout period. A blinded observer evaluated heart rate (HR), palpebral and corneal reflexes, muscle relaxation, handling, and response to toe pinch at the following points: pre-injection, and 5, 12, 20, 30, 45, 60, and 120 minutes post-injection. Turtles then acclimated to 18-20 °C for 63 days, and the experiment was repeated in this lower-temperature environment, with treatment groups C10 (alfaxalone 10 mg kg(-1)) and C20 (alfaxalone 20 mg kg(-1)) subjected to the same crossover design. C10 and C20 groups had significantly lower intraanesthetic HR than W10 or W20, respectively. C10 and W20 were significantly more relaxed and easier to handle than W10. No significant differences were observed in palpebral reflex, nor responsiveness to the toe pinch stimulus. None of the turtles lost corneal reflex. W20 and C20 had prolonged recoveries, compared to low-dose groups within the same temperature environment. Recovery was also longer at C20 and C10 compared to W10. Turtles given 10 mg kg(-1) were more relaxed and easier to handle in cold than warm conditions. Warm turtles were more relaxed and easier to handle when given 20 mg kg(-1) than those given 10 mg kg(-1). Cold conditions correlated with lower HR and longer recovery time for each dose category. The turtles had dose-dependent and inconsistent responses to alfaxalone. Lower ambient temperature augmented the behavioral effects of this drug. © 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  14. The Segue K giant survey. II. A catalog of distance determinations for the Segue K giants in the galactic halo

    International Nuclear Information System (INIS)

    Xue, Xiang-Xiang; Rix, Hans-Walter; Ma, Zhibo; Morrison, Heather L.; Harding, Paul; Beers, Timothy C.; Ivans, Inese I.; Jacobson, Heather R.; Johnson, Jennifer; Lee, Young Sun; Lucatello, Sara; Rockosi, Constance M.; Sobeck, Jennifer S.; Yanny, Brian; Zhao, Gang; Allende Prieto, Carlos

    2014-01-01

    We present an online catalog of distance determinations for 6036 K giants, most of which are members of the Milky Way's stellar halo. Their medium-resolution spectra from the Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding and Exploration are used to derive metallicities and rough gravity estimates, along with radial velocities. Distance moduli are derived from a comparison of each star's apparent magnitude with the absolute magnitude of empirically calibrated color-luminosity fiducials, at the observed (g – r) 0 color and spectroscopic [Fe/H]. We employ a probabilistic approach that makes it straightforward to properly propagate the errors in metallicities, magnitudes, and colors into distance uncertainties. We also fold in prior information about the giant-branch luminosity function and the different metallicity distributions of the SEGUE K-giant targeting sub-categories. We show that the metallicity prior plays a small role in the distance estimates, but that neglecting the luminosity prior could lead to a systematic distance modulus bias of up to 0.25 mag, compared to the case of using the luminosity prior. We find a median distance precision of 16%, with distance estimates most precise for the least metal-poor stars near the tip of the red giant branch. The precision and accuracy of our distance estimates are validated with observations of globular and open clusters. The stars in our catalog are up to 125 kpc from the Galactic center, with 283 stars beyond 50 kpc, forming the largest available spectroscopic sample of distant tracers in the Galactic halo.

  15. Non-syndromic multiple impacted supernumerary teeth with peripheral giant cell granuloma

    Directory of Open Access Journals (Sweden)

    Pankaj Bansal

    2011-01-01

    Full Text Available Peripheral giant cell granuloma (PGCG is a relatively frequent benign reactive lesion of the gingiva, originating from the periosteum or periodontal membrane following local irritation or chronic trauma. PGCG manifests as a red-purple nodule located in the region of the gingiva or edentulous alveolar margins. The lesion can develop at any age, although it is more common between the second and third decades of life, and shows a slight female predilection. PGCG is a soft tissue lesion that very rarely affects the underlying bone, although the latter may suffer superficial erosion. A supernumerary tooth is one that is additional to the normal series and can be found in almost any region of the dental arch. These teeth may be single, multiple, erupted or unerupted and may or may not be associated with syndrome. Usually, they cause one or the other problem in eruption or alignment of teeth, but may also present without disturbing the normal occlusion or eruption pattern. Management of these teeth depends on the symptoms. Presented here is a case of PGCG in relation to the lower left permanent first molar with three supernumerary teeth in the mandibular arch but no associated syndrome.

  16. Characterization of the gut microbiota in the red panda (Ailurus fulgens.

    Directory of Open Access Journals (Sweden)

    Fanli Kong

    Full Text Available The red panda is the only living species of the genus Ailurus. Like giant pandas, red pandas are also highly specialized to feed mainly on highly fibrous bamboo. Although several studies have focused on the gut microbiota in the giant panda, little is known about the gut microbiota of the red panda. In this study, we characterized the fecal microbiota from both wild (n = 16 and captive (n = 6 red pandas using a pyrosequecing based approach targeting the V1-V3 hypervariable regions of the 16S rRNA gene. Distinct bacterial communities were observed between the two groups based on both membership and structure. Wild red pandas maintained significantly higher community diversity, richness and evenness than captive red pandas, the communities of which were skewed and dominated by taxa associated with Firmicutes. Phylogenetic analysis of the top 50 OTUs revealed that 10 of them were related to known cellulose degraders. To the best of our knowledge, this is the first study of the gut microbiota of the red panda. Our data suggest that, similar to the giant panda, the gut microbiota in the red panda might also play important roles in the digestion of bamboo.

  17. Characterization of the gut microbiota in the red panda (Ailurus fulgens).

    Science.gov (United States)

    Kong, Fanli; Zhao, Jiangchao; Han, Shushu; Zeng, Bo; Yang, Jiandong; Si, Xiaohui; Yang, Benqing; Yang, Mingyao; Xu, Huailiang; Li, Ying

    2014-01-01

    The red panda is the only living species of the genus Ailurus. Like giant pandas, red pandas are also highly specialized to feed mainly on highly fibrous bamboo. Although several studies have focused on the gut microbiota in the giant panda, little is known about the gut microbiota of the red panda. In this study, we characterized the fecal microbiota from both wild (n = 16) and captive (n = 6) red pandas using a pyrosequecing based approach targeting the V1-V3 hypervariable regions of the 16S rRNA gene. Distinct bacterial communities were observed between the two groups based on both membership and structure. Wild red pandas maintained significantly higher community diversity, richness and evenness than captive red pandas, the communities of which were skewed and dominated by taxa associated with Firmicutes. Phylogenetic analysis of the top 50 OTUs revealed that 10 of them were related to known cellulose degraders. To the best of our knowledge, this is the first study of the gut microbiota of the red panda. Our data suggest that, similar to the giant panda, the gut microbiota in the red panda might also play important roles in the digestion of bamboo.

  18. Giant first-forbidden resonances

    International Nuclear Information System (INIS)

    Krmpotic, F.; Nakayama, K.; Sao Paulo Univ.; Pio Galeao, A.; Sao Paulo Univ.

    1983-01-01

    Recent experimental data on first-forbidden charge-exchange resonances are discussed in the framework of a schematic model. We also evaluate the screening of the weak coupling constants induced by both the giant resonances and the δ-isobar. It is shown that the last effect does not depend on the multipolarity of the one-particle moment. Due to the same reason, the fraction of the reaction strength pushed up into the δ-resonance region is always the same regardless of the quantum numbers carried by the excitation. Simple expressions are derived for the dependence of the excitation energies of the first-forbidden giant resonances on the mass number and isospin of the target. The model reproduces consistently both the Gamow-Teller and the first-forbidden resonances. (orig.)

  19. Giant Low Surface Brightness Galaxies

    Science.gov (United States)

    Mishra, Alka; Kantharia, Nimisha G.; Das, Mousumi

    2018-04-01

    In this paper, we present radio observations of the giant low surface brightness (LSB) galaxies made using the Giant Metrewave Radio Telescope (GMRT). LSB galaxies are generally large, dark matter dominated spirals that have low star formation efficiencies and large HI gas disks. Their properties suggest that they are less evolved compared to high surface brightness galaxies. We present GMRT emission maps of LSB galaxies with an optically-identified active nucleus. Using our radio data and archival near-infrared (2MASS) and near-ultraviolet (GALEX) data, we studied morphology and star formation efficiencies in these galaxies. All the galaxies show radio continuum emission mostly associated with the centre of the galaxy.

  20. Giant condyloma acuminatum of vulva

    Directory of Open Access Journals (Sweden)

    S. M. Ramiz Ahmed

    2017-09-01

    Full Text Available In this paper, A 23 year old married woman who was diagnosed as a case of giant condyloma acuminatum of vulva measuring about 15 x 8 x 3 cm, irregular surface with multiple projections, oval in shape, firm to hard in consistency, mildly tender, exophytic, cauliflower like growth involving the whole vulva (lower part of mons pubis, labia, vestibule, clitoris, around vaginal opening. Another multiple small lesions were present at perineal region but there was no inguinal lymphadenopathy. She underwent a combined electro cauterization and cryotherapy for small to moderate size multiple primary and recurrent warty lesions and wide surgical excision with fasciocutaneous advancement flaps procedure for a giant lesions in the vulva. Excisional biopsies were performed to detect potential malignancy but malignancy was not found histologically. The patient was advised to first follow-up 1 month after operation when multiple small warty lesions were developed and treated and the subsequent follow-ups for 3 months.

  1. A Giant Juvenile Nasopharyngeal Angiofibroma

    Science.gov (United States)

    Yüce, Salim; Uysal, İsmail Önder; Doğan, Mansur; Polat, Kerem; Şalk, İsmail; Müderris, Suphi

    2012-01-01

    Juvenile nasopharyngeal angiofibroma (JNA) are locally growing highly vascular tumours. They are treated primarily by surgical excision ranging from open approach to endoscopic approach. We presented a 20-year-old male with a giant nasopharyngeal juvenile angiofibroma obliterating the pterygopalatine fossa bilaterally, invasing the sphenoid bone and extending to the left nasal passage. His complaints were epistaxis and nasal obstruction. After embolization, the patient was treated surgically with endoscopic approach and discharged as cured without any complication. PMID:23714961

  2. [Treatment of giant acoustic neuromas].

    Science.gov (United States)

    Samprón, Nicolás; Altuna, Xabier; Armendáriz, Mikel; Urculo, Enrique

    2014-01-01

    To analyze the treatment modality and outcome of a series of patients with giant acoustic neuromas, a particular type of tumour characterised by their size (extracanalicular diameter of 4cm or more) and high morbidity and mortality. This was a retrospective unicentre study of patients with acoustic neuromas treated in a period of 12 years. In our institutional series of 108 acoustic neuromas operated on during that period, we found 13 (12%) cases of giant acoustic neuromas. We reviewed the available data of these cases, including presentation and several clinical, anatomical, and microsurgical aspects. All patients were operated on by the same neurosurgeon and senior author (EU) using the suboccipital retrosigmoid approach and complete microsurgical removal was achieved in 10 cases. In one case, near total removal was deliberately performed, in another case a CSF shunt was placed as the sole treatment measure, and in the remaining case no direct treatment was given. One patient died in the immediate postoperative period. One year after surgery, 4 patients showed facial nerve function of iii or more in the House-Brackman scale. The 4 most important prognostic characteristics of giant acoustic neuromas are size, adhesion to surrounding structures, consistency and vascularity. Only the first of these is evident in neuroimaging. Giant acoustic neuromas are characterised by high morbidity at presentation as well as after treatment. Nevertheless, the objective of complete microsurgical removal with preservation of cranial nerve function is attainable in some cases through the suboccipital retrosigmoid approach. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  3. Germination of red alder seed.

    Science.gov (United States)

    M.A. Radwan; D.S. DeBell

    1981-01-01

    Red alder seeds were collected from six locations throughout the natural range of the species. Each seed lot was obtained from a single tree, and the seeds were used to determine germination with and without stratification treatment. Irrespective of treatment, germination varied significantly (P

  4. Giant Planets: Good Neighbors for Habitable Worlds?

    Science.gov (United States)

    Georgakarakos, Nikolaos; Eggl, Siegfried; Dobbs-Dixon, Ian

    2018-04-01

    The presence of giant planets influences potentially habitable worlds in numerous ways. Massive celestial neighbors can facilitate the formation of planetary cores and modify the influx of asteroids and comets toward Earth analogs later on. Furthermore, giant planets can indirectly change the climate of terrestrial worlds by gravitationally altering their orbits. Investigating 147 well-characterized exoplanetary systems known to date that host a main-sequence star and a giant planet, we show that the presence of “giant neighbors” can reduce a terrestrial planet’s chances to remain habitable, even if both planets have stable orbits. In a small fraction of systems, however, giant planets slightly increase the extent of habitable zones provided that the terrestrial world has a high climate inertia. In providing constraints on where giant planets cease to affect the habitable zone size in a detrimental fashion, we identify prime targets in the search for habitable worlds.

  5. Single-photon emission computed tomography enhanced Tc-99m-pertechnetate disodium-labelled red blood cell scintigraphy in the localization of small intestine bleeding: a single-centre twelve-year study.

    Science.gov (United States)

    Dolezal, Jiri; Vizda, Jaroslav; Kopacova, Marcela

    2011-01-01

    To present our experience with the detection of bleeding in the small intestine by means of scintigraphy with in vivo-labelled red blood cells (RBCs) in the period of 1998-2009. A 12-year prospective study was accomplished with 40 patients (23 men, 17 women, aged 12-91, mean 56 years) who had lower gastrointestinal bleeding (obscure-overt bleeding) and underwent scintigraphy with in vivo-labelled RBCs by means of technetium 99m. The scintigraphy was usually performed after other diagnostic tests had failed to locate the bleeding. A total of 26 patients had a positive scintigraphy with in vivo-labelled RBCs and 14 patients had negative scintigraphy. The final diagnosis was confirmed in 20 of 26 patients with a positive scintigraphy by push enteroscopy (6/20), intraoperative enteroscopy (7/20), surgery (4/20), duodenoscopy (1/20), double-balloon enteroscopy (1/20) and X-ray angiography (1/20). The correct location of the bleeding site was identified by RBC scintigraphy in 15 of 20 (75%) patients with the confirmed source. The locations of the bleeding site identified by scintigraphy and enteroscopy (push, intraoperative) and surgical investigations were highly correlated in patients with a positive scintigraphy within the first 3 h. Eleven of the 20 correctly localized studies and none of the incorrectly localized studies were positive in the dynamic phase of imaging. In 5 patients (all erroneously localized), scintigraphy was positive only at a period longer than 18 h. RBC scintigraphy is an effective imaging modality in localizing lower gastrointestinal bleeding in patients for whom other diagnostic tests have failed to locate the bleeding. RBC scintigraphy can be successful in the detection of bleeding sites in the small intestine. Copyright © 2011 S. Karger AG, Basel.

  6. BD+15 2940 AND HD 233604: TWO GIANTS WITH PLANETS CLOSE TO THE ENGULFMENT ZONE

    International Nuclear Information System (INIS)

    Nowak, G.; Niedzielski, A.; Adamów, M.; Maciejewski, G.; Wolszczan, A.

    2013-01-01

    We report the discovery of planetary-mass companions to two red giants by the ongoing Penn State-Toruń Planet Search (PTPS) conducted with the 9.2 m Hobby-Eberly Telescope. The 1.1 M ☉ K0-giant, BD+15 2940, has a 1.1 M J minimum mass companion orbiting the star at a 137.5 day period in a 0.54 AU orbit what makes it the closest—in planet around a giant and possible subject of engulfment as the consequence of stellar evolution. HD 233604, a 1.5 M ☉ K5-giant, is orbited by a 6.6 M J minimum mass planet which has a period of 192 days and a semi-major axis of only 0.75 AU making it one of the least distant planets to a giant star. The chemical composition analysis of HD 233604 reveals a relatively high 7 Li abundance which may be a sign of its early evolutionary stage or recent engulfment of another planet in the system. We also present independent detections of planetary-mass companions to HD 209458 and HD 88133, and stellar activity-induced radial velocity variations in HD 166435, as part of the discussion of the observing and data analysis methods used in the PTPS project.

  7. Solitary ulcerated congenital giant juvenile xanthogranuloma

    Directory of Open Access Journals (Sweden)

    Su Yuen Ng

    2015-01-01

    Full Text Available A 3-month-old female patient with a giant ulcerated nodule over the back since birth was diagnosed as congenital giant juvenile xanthogranuloma (JXG based on clinical and histopathological examination. Congenital giant JXG with ulceration at birth is a rare presentation of JXG and commonly misdiagnosed. This case emphasizes the importance of being aware of the myriad presentations of JXG in order to make a correct diagnosis and avoid unnecessary investigations or treatment.

  8. Giant resonances in heavy-ion reactions

    International Nuclear Information System (INIS)

    Hussein, M.S.

    1982-11-01

    The several roles of multipole giant resonances in heavy-ion reactions are discussed. In particular, the modifications in the effective ion-ion potencial due to the virtual excitation of giant resonances at low energies, are considered and estimated for several systems. Real excitation of giant resonances in heavy-ion reactions at intermediate energies are then discussed and their importance in the approach phase of deeply inelastic processes in emphasized. Several demonstrative examples are given. (Author) [pt

  9. Giant multipole resonances: an experimental review

    International Nuclear Information System (INIS)

    Bertrand, F.E.

    1979-01-01

    During the past several years experimental evidence has been published for the existance of nondipole giant resonances. These giant multipole resonances, the so-called new giant resonances were first observed through inelastic hadron and electron scattering and such measurements have continued to provide most of the information in this field. A summary is provided of the experimental evidence for these new resonances. The discussion deals only with results from inelastic scattering and only with the electric multipoles. Emphasis is placed on the recent observations of the giant monopole resonance. Results from recent heavy-ion and pion inelastic scattering are discussed. 38 references

  10. Giant dipole resonance in hot nuclei

    International Nuclear Information System (INIS)

    Mau, N.V.

    1993-01-01

    Giant resonances built on an excited state of the nucleus at a finite temperature T are studied. The following questions are investigated: how long such collective effects occur in a nucleus when T increases. How the properties of the giant resonances vary when the temperature increases. How the study of giant resonances in hot nuclei can give information on the structure of the nucleus in a highly excited state. The special case of the giant dipole resonance is studied. Some of the experimental results are reviewed and in their theoretical interpretation is discussed. (K.A.). 56 refs., 20 figs., 4 tabs

  11. Ulcerative giant solitary trichoepithelioma of scalp: a rare presentation

    Directory of Open Access Journals (Sweden)

    Sundeep Chowdhry

    2016-07-01

    Full Text Available Trichoepithelioma is a trichogenic tumor which arises from the inferior segment of hair follicle epithelium as hamartoma. Giant solitary trichoepithelioma (GST has been defined as a solitary trichoepithelioma with a diameter greater than 2 cm. A 49-year-old female presented with a slow growing skin coloured swelling on the scalp of 8 years duration with recent history of ulceration and occasional bleeding. The local examination revealed a single well defined nodular swelling which was irregular in shape measuring approximately 2 × 2.5 cm. Histopathology from biopsy specimen revealed dark basaloid cells with scanty cytoplasm and darkly stained nucleus arranged in nests with horn cysts lacking high-grade atypia and mitosis, which was consistent with features of trichoepithelioma. Giant solitary trichoepithelioma of scalp is itself a rare entity and the present case is being reported with the additional component of ulceration in the lesion.

  12. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 11a: giant sequoias

    Science.gov (United States)

    York, Robert A.; Stephenson, Nathan L.; Meyer, Marc; Hanna, Steve; Tadashi, Moody; Caprio, Anthony C.; Battles, John J.

    2013-01-01

    For natural resource managers in the southern Sierra Nevada, giant sequoia requires very little introduction. It receives great attention as an icon of western forests and as a common namesake with the areas where it occurs. While it is a single component of a very complex system, its attention in this assessment and in general is well deserved. Giant sequoia is one of the few "destination species" that attracts a wide swath of the public by nature of it simply being present. It draws people, who otherwise may not travel, to a natural environment. The result is an expansion of the public’s sense of natural resource stewardship. Because park managers could not achieve their mission without public support, this fostering role of giant sequoia is critical for park natural resources and is important for natural resources in general. Despite its social relevance and physical size, we re-emphasize here that the giant sequoia resource is a relatively small component of the ecosystems of the southern Sierra Nevada. As is the case with all of the resources assessed in the NRCA, we focus on giant sequoia with the understanding that other resources will be considered simultaneously when evaluating management decisions that impact giant sequoia. While we attempt to explicitly address the interaction of giant sequoia with other resources and stressors, we also realize that ultimately managers will integrate much more information than is presented here when making decisions that influence giant sequoia. The autecology and management issues surrounding giant sequoia have been thoroughly reviewed elsewhere (Harvey et al. 1980, Aune 1994, Stephenson 1996). Stephenson (1996), in particular, should be reviewed when considering any management decisions that potentially impact giant sequoia. For those who may not be familiar with giant sequoia ecology, a summary of basic information is provided in a table below. In some parts of this assessment, we reproduce text from Stephenson

  13. Evolution models of helium white dwarf--main-sequence star merger remnants: the mass distribution of single low-mass white dwarfs

    OpenAIRE

    Zhang, Xianfei; Hall, Philip D.; Jeffery, C. Simon; Bi, Shaolan

    2017-01-01

    It is not known how single white dwarfs with masses less than 0.5Msolar -- low-mass white dwarfs -- are formed. One way in which such a white dwarf might be formed is after the merger of a helium-core white dwarf with a main-sequence star that produces a red giant branch star and fails to ignite helium. We use a stellar-evolution code to compute models of the remnants of these mergers and find a relation between the pre-merger masses and the final white dwarf mass. Combining our results with ...

  14. ASTEROSEISMIC-BASED ESTIMATION OF THE SURFACE GRAVITY FOR THE LAMOST GIANT STARS

    International Nuclear Information System (INIS)

    Liu, Chao; Wu, Yue; Deng, Li-Cai; Wang, Liang; Wang, Wei; Li, Guang-Wei; Fang, Min; Fu, Jian-Ning; Hou, Yong-Hui; Zhang, Yong

    2015-01-01

    Asteroseismology is one of the most accurate approaches to estimate the surface gravity of a star. However, most of the data from the current spectroscopic surveys do not have asteroseismic measurements, which is very expensive and time consuming. In order to improve the spectroscopic surface gravity estimates for a large amount of survey data with the help of the small subset of the data with seismic measurements, we set up a support vector regression (SVR) model for the estimation of the surface gravity supervised by 1374 Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) giant stars with Kepler seismic surface gravity. The new approach can reduce the uncertainty of the estimates down to about 0.1 dex, which is better than the LAMOST pipeline by at least a factor of 2, for the spectra with signal-to-noise ratio higher than 20. Compared with the log g estimated from the LAMOST pipeline, the revised log g values provide a significantly improved match to the expected distribution of red clump and red giant branch stars from stellar isochrones. Moreover, even the red bump stars, which extend to only about 0.1 dex in log g, can be discriminated from the new estimated surface gravity. The method is then applied to about 350,000 LAMOST metal-rich giant stars to provide improved surface gravity estimates. In general, the uncertainty of the distance estimate based on the SVR surface gravity can be reduced to about 12% for the LAMOST data

  15. ASTEROSEISMIC-BASED ESTIMATION OF THE SURFACE GRAVITY FOR THE LAMOST GIANT STARS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chao; Wu, Yue; Deng, Li-Cai; Wang, Liang; Wang, Wei; Li, Guang-Wei [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20 A Datun Road, Beijing 100012 (China); Fang, Min [Departamento de Física Teórica, Facultad de Ciencias, Universidad Autonóma de Madrid, E-28049 Cantoblanco, Madrid (Spain); Fu, Jian-Ning [Department of Astronomy, Beijing Normal University, 19 Avenue Xinjiekouwai, Beijing 100875 (China); Hou, Yong-Hui; Zhang, Yong, E-mail: liuchao@nao.cas.cn [Nanjing Institute of Astronomical Optics and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Nanjing 210042 (China)

    2015-07-01

    Asteroseismology is one of the most accurate approaches to estimate the surface gravity of a star. However, most of the data from the current spectroscopic surveys do not have asteroseismic measurements, which is very expensive and time consuming. In order to improve the spectroscopic surface gravity estimates for a large amount of survey data with the help of the small subset of the data with seismic measurements, we set up a support vector regression (SVR) model for the estimation of the surface gravity supervised by 1374 Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) giant stars with Kepler seismic surface gravity. The new approach can reduce the uncertainty of the estimates down to about 0.1 dex, which is better than the LAMOST pipeline by at least a factor of 2, for the spectra with signal-to-noise ratio higher than 20. Compared with the log g estimated from the LAMOST pipeline, the revised log g values provide a significantly improved match to the expected distribution of red clump and red giant branch stars from stellar isochrones. Moreover, even the red bump stars, which extend to only about 0.1 dex in log g, can be discriminated from the new estimated surface gravity. The method is then applied to about 350,000 LAMOST metal-rich giant stars to provide improved surface gravity estimates. In general, the uncertainty of the distance estimate based on the SVR surface gravity can be reduced to about 12% for the LAMOST data.

  16. ON INFRARED EXCESSES ASSOCIATED WITH Li-RICH K GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Rebull, Luisa M. [Spitzer Science Center (SSC) and Infrared Science Archive (IRSA), Infrared Processing and Analysis Center - IPAC, 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Carlberg, Joleen K. [NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Gibbs, John C.; Cashen, Sarah; Datta, Ashwin; Hodgson, Emily; Lince, Megan [Glencoe High School, 2700 NW Glencoe Rd., Hillsboro, OR 97124 (United States); Deeb, J. Elin [Bear Creek High School, 9800 W. Dartmouth Pl., Lakewood, CO 80227 (United States); Larsen, Estefania; Altepeter, Shailyn; Bucksbee, Ethan; Clarke, Matthew [Millard South High School, 14905 Q St., Omaha, NE 68137 (United States); Black, David V., E-mail: rebull@ipac.caltech.edu [Walden School of Liberal Arts, 4230 N. University Ave., Provo, UT 84604 (United States)

    2015-10-15

    Infrared (IR) excesses around K-type red giants (RGs) have previously been discovered using Infrared Astronomy Satellite (IRAS) data, and past studies have suggested a link between RGs with overabundant Li and IR excesses, implying the ejection of circumstellar shells or disks. We revisit the question of IR excesses around RGs using higher spatial resolution IR data, primarily from the Wide-field Infrared Survey Explorer. Our goal was to elucidate the link between three unusual RG properties: fast rotation, enriched Li, and IR excess. Our sample of RGs includes those with previous IR detections, a sample with well-defined rotation and Li abundance measurements with no previous IR measurements, and a large sample of RGs asserted to be Li-rich in the literature; we have 316 targets thought to be K giants, about 40% of which we take to be Li-rich. In 24 cases with previous detections of IR excess at low spatial resolution, we believe that source confusion is playing a role, in that either (a) the source that is bright in the optical is not responsible for the IR flux, or (b) there is more than one source responsible for the IR flux as measured in IRAS. We looked for IR excesses in the remaining sources, identifying 28 that have significant IR excesses by ∼20 μm (with possible excesses for 2 additional sources). There appears to be an intriguing correlation in that the largest IR excesses are all in Li-rich K giants, though very few Li-rich K giants have IR excesses (large or small). These largest IR excesses also tend to be found in the fastest rotators. There is no correlation of IR excess with the carbon isotopic ratio, {sup 12}C/{sup 13}C. IR excesses by 20 μm, though relatively rare, are at least twice as common among our sample of Li-rich K giants. If dust shell production is a common by-product of Li enrichment mechanisms, these observations suggest that the IR excess stage is very short-lived, which is supported by theoretical calculations. Conversely, the

  17. The conjunction of factors that lead to formation of giant gold provinces and deposits in non-arc settings

    Science.gov (United States)

    Groves, David I.; Goldfarb, Richard J.; Santosh, M.

    2016-01-01

    It is quite evident that it is not anomalous metal transport, nor unique depositional conditions, nor any single factor at the deposit scale, that dictates whether a mineral deposit becomes a giant or not. A hierarchical approach thus is required to progressively examine controlling parameters at successively decreasing scales in the total mineral system to understand the location of giant gold deposits in non-arc environments. For giant orogenic, intrusion-related gold systems (IRGS) and Carlin-type gold deposits and iron oxide-copper-gold (IOCG) deposits, there are common factors among all of these at the lithospheric to crustal scale. All are sited in giant gold provinces controlled by complex fundamental fault or shear zones that follow craton margins or, in the case of most Phanerozoic orogenic giants, define the primary suture zones between tectonic terranes. Giant provinces of IRGS, IOCG, and Carlin-type deposits require melting of metasomatized lithosphere beneath craton margins with ascent of hybrid lamprophyric to granitic magmas and associated heat flux to generate the giant province. The IRGS and IOCG deposits require direct exsolution of volatile-rich magmatic-hydrothermal fluids, whereas the association of such melts with Carlin-type ores is more indirect and enigmatic. Giant orogenic gold provinces show no direct relationship to such magmatism, forming from metamorphic fluids, but show an indirect relationship to lamprophyres that reflect the mantle connectivity of controlling first-order structures.

  18. Multinucleated Giant Cancer Cells Produced in Response to Ionizing Radiation Retain Viability and Replicate Their Genome

    Directory of Open Access Journals (Sweden)

    Razmik Mirzayans

    2017-02-01

    Full Text Available Loss of wild-type p53 function is widely accepted to be permissive for the development of multinucleated giant cells. However, whether therapy-induced multinucleation is associated with cancer cell death or survival remains controversial. Herein, we demonstrate that exposure of p53-deficient or p21WAF1 (p21-deficient solid tumor-derived cell lines to ionizing radiation (between 2 and 8 Gy results in the development of multinucleated giant cells that remain adherent to the culture dish for long times post-irradiation. Somewhat surprisingly, single-cell observations revealed that virtually all multinucleated giant cells that remain adherent for the duration of the experiments (up to three weeks post-irradiation retain viability and metabolize 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl-tetrazolium bromide (MTT, and the majority (>60% exhibit DNA synthesis. We further report that treatment of multinucleated giant cells with pharmacological activators of apoptosis (e.g., sodium salicylate triggers their demise. Our observations reinforce the notion that radiation-induced multinucleation may reflect a survival mechanism for p53/p21-deficient cancer cells. With respect to evaluating radiosensitivity, our observations underscore the importance of single-cell experimental approaches (e.g., single-cell MTT as the creation of viable multinucleated giant cells complicates the interpretation of the experimental data obtained by commonly-used multi-well plate colorimetric assays.

  19. Mixing core material into the envelopes of red grants

    International Nuclear Information System (INIS)

    Deupree, R.G.

    1986-01-01

    A discussion is presented of calculations of four core helium flashes in red giant stars. The starting point for these calculations is a point source explosion on the polar axis of a two-dimensional finite difference grid. The amount of residue of the core helium flash mixed into and above the hydrogen shell is calculated at four temperatures for the elements carbon, oxygen, neon, magnesium, silicon, and sulfur. 7 refs., 1 tab

  20. Evolution of the giant planets

    International Nuclear Information System (INIS)

    Bodenheimer, P.

    1985-01-01

    The theory of the evolution of the giant planets is discussed with emphasis on detailed numerical calculations in the spherical approximation. Initial conditions are taken to be those provided by the two main hypotheses for the origin of the giant planets. If the planets formed by gravitational instability in the solar nebula, the initial mass is comparable to the present mass or larger. The evolution then goes through the following phases: (1) an initial contraction phase in hydrostatic equilibrium; (2) a hydrodynamic collapse induced by molecular dissociation; and (3) a second equilibrium phase involving contraction and cooling to the present state. During phase (1) a rock-ice core must form by precipitation or accretion. If, on the other hand, the giant planets formed by first accreting a solid core and then capturing gas from the surrounding nebula, then the evolutionary phases are as follows: (1) a period during which planetesimals accrete to form a core of about one earth mass, composed of rock and ice; (2) a gas accretion phase, during which a relatively low-mass gaseous envelope in hydrostatic equilibrium exists around the core, which itself continues to grow to 10 to 20 Earth masses; (3) the point of arrival at the ''critical'' core mass at which point the accretion of gas is much faster than the accretion of the core, and the envelope contracts rapidly; (4) continuation of accretion of gas from the nebula and buildup of the envelope mass to its present value (for the case of Jupiter or Saturn); and (5) a final phase, after termination of accretion, during which the protoplanet contracts and cools to its present state. Some observational constraints are described, and some problems with the two principal hypotheses are discussed

  1. Giant magneto-resistance devices

    CERN Document Server

    Hirota, Eiichi; Inomata, Koichiro

    2002-01-01

    This book deals with the application of giant magneto-resistance (GMR) effects to electronic devices. It will appeal to engineers and graduate students in the fields of electronic devices and materials. The main subjects are magnetic sensors with high resolution and magnetic read heads with high sensitivity, required for hard-disk drives with recording densities of several gigabytes. Another important subject is novel magnetic random-access memories (MRAM) with non-volatile non-destructive and radiation-resistant characteristics. Other topics include future GMR devices based on bipolar spin transistors, spin field-effect transistors (FETs) and double-tunnel junctions.

  2. Nutritional evaluation of the giant grassropper (Zonocerus ...

    African Journals Online (AJOL)

    The biological value of giant grasshopper protein (Zonocerus variegatus) was evaluated by comparing the weight gained, food efficiency ratio (FER), protein efficiency ratio (PER) of rats fed standard laboratory chow with that of rats fed giant grasshopper, Soyabean(Glycine max) and crayfish. The effect of high fibre content ...

  3. Static electromagnetic properties of giant resonances

    International Nuclear Information System (INIS)

    Koo, W.K.

    1986-03-01

    Static electric monopole and quadrupole matrix elements, which are related to the mean square radius and quadrupole moment respectively, are derived for giant resonances of arbitrary multipolarity. The results furnish information on the size and shape of the nucleus in the excited giant states. (author)

  4. Totally thrombosed giant anterior communicating artery aneurysm

    Directory of Open Access Journals (Sweden)

    V R Roopesh Kumar

    2015-01-01

    Full Text Available Giant anterior communicating artery aneurysmsarerare. Apatient presented with visual dysfunction, gait ataxia and urinary incontinence. MRI showed a giant suprasellar mass.At surgery, the lesion was identified as being an aneurysm arising from the anterior communicating artery.The difficulty in preoperative diagnosis and relevant literature are reviewed.

  5. The red supergiant population in the Perseus arm

    Science.gov (United States)

    Dorda, R.; Negueruela, I.; González-Fernández, C.

    2018-04-01

    We present a new catalogue of cool supergiants in a section of the Perseus arm, most of which had not been previously identified. To generate it, we have used a set of well-defined photometric criteria to select a large number of candidates (637) that were later observed at intermediate resolution in the infrared calcium triplet spectral range, using a long-slit spectrograph. To separate red supergiants from luminous red giants, we used a statistical method, developed in previous works and improved in the present paper. We present a method to assign probabilities of being a red supergiant to a given spectrum and use the properties of a population to generate clean samples, without contamination from lower luminosity stars. We compare our identification with a classification done using classical criteria and discuss their respective efficiencies and contaminations as identification methods. We confirm that our method is as efficient at finding supergiants as the best classical methods, but with a far lower contamination by red giants than any other method. The result is a catalogue with 197 cool supergiants, 191 of which did not appear in previous lists of red supergiants. This is the largest coherent catalogue of cool supergiants in the Galaxy.

  6. DETERMINING AGES OF APOGEE GIANTS WITH KNOWN DISTANCES

    Energy Technology Data Exchange (ETDEWEB)

    Feuillet, Diane K.; Holtzman, Jon [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Bovy, Jo [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Girardi, Léo [Osservatorio Astronomico di Padova—INAF, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); MacDonald, Nick [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Nidever, David L., E-mail: feuilldk@nmsu.edu [Large Synoptic Survey Telescope, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

    2016-01-20

    We present a sample of 705 local giant stars observed using the New Mexico State University 1 m telescope with the Sloan Digital Sky Survey-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, for which we estimate stellar ages and the local star formation history (SFH). The high-resolution (R ∼ 22,500), near infrared (1.51–1.7 μm) APOGEE spectra provide measurements of stellar atmospheric parameters (temperature, surface gravity, [M/H], and [α/M]). Due to the smaller uncertainties in surface gravity possible with high-resolution spectra and accurate Hipparcos distance measurements, we are able to calculate the stellar masses to within 30%. For giants, the relatively rapid evolution up the red giant branch allows the age to be constrained by the mass. We examine methods of estimating age using both the mass–age relation directly and a Bayesian isochrone matching of measured parameters, assuming a constant SFH. To improve the SFH prior, we use a hierarchical modeling approach to constrain the parameters of the model SFH using the age probability distribution functions of the data. The results of an α-dependent Gaussian SFH model show a clear age–[α/M] relation at all ages. Using this SFH model as the prior for an empirical Bayesian analysis, we determine ages for individual stars. The resulting age–metallicity relation is flat, with a slight decrease in [M/H] at the oldest ages and a ∼0.5 dex spread in metallicity across most ages. For stars with ages ≲1 Gyr we find a smaller spread, consistent with radial migration having a smaller effect on these young stars than on the older stars.

  7. Properties of minimum-flux coronae in dwarfs and giants

    International Nuclear Information System (INIS)

    Mullan, D.J.

    1976-01-01

    Using a method due to Hearn, we examine the properties of minimum-flux coronae in dwarfs and giants. If the fraction phi of the total stellar luminosity which is used to heat the corona is equal to the solar value phi/sub s/, then red dwarfs must have coronae that are cooler than the solar corona: in UV Ceti, for example, the coronal temperature is a factor 3 less than in the Sun. This is consistent with an independent estimate of coronal temperature in a flare star. If phi=phi/sub s/, main-sequence stars hotter than the Sun have coronae which are hotter than the solar corona. Soft X-rays from Sirius suggest that the coronal temperature in Sirius is indeed hotter than the Sun by a factor of about 40 percent. Giants show an even more marked decrease in coronal temperature at later spectral type than do the dwarfs. We suggest that the reason for the presence of O V emission in β Gem and O VI emission in α Aur, and the absence of O V emission in α Boo and α Tau, is that the coronae in the latter two stars are cooler (rather than hotter, as McClintock et al. have suggested) than in the former two. Our results explain why it is more likely that mass loss has been detected in α Aur and α Boo, but not in α Tau or β Gem. Using a simple flare model, we show that flares in both a dwarf star (UV Ceti) and a giant (α Aur) were initiated not in the corona, but in the transition region

  8. Electromagnetic decay of giant resonances

    International Nuclear Information System (INIS)

    Beene, J.R.; Bertrand, F.E.; Halbert, M.L.; Auble, R.L.; Hensley, D.C.; Horen, D.J.; Robinson, R.L.; Sayer, R.O.; Sjoreen, T.P.

    1985-01-01

    Coincidence experiments were done to investigate the photon and neutron emission from the giant resonance regions of 208 Pb and 90 Zr using the ORNL Spin Spectrometer, a 72-segment NaI detector system. We have determined the total gamma-decay probability, the ground-state gamma branching ratio, and the branching ratios to a number of low-lying states as a function of excitation energy in 208 Pb to approx.15 MeV. Similar data were also obtained on 90 Zr. The total yield of ground-state E2 gamma radiation in 208 Pb and the comparative absence of such radiation in 90 Zr can only be understood if decay of compound (damped) states is considered. Other observations in 208 Pb include the absence of a significant branch from the giant quadrupole resonance (GQR) to the 3 - state at 2.6 MeV, a strong branch to a 3 - state at 4.97 MeV from the same region, and transitions to various 1 - states between 5 to 7 MeV from the E* approx. 14 MeV region (EO resonance)

  9. Crystal engineering of giant molecules based on perylene diimide conjugated polyhedral oligomeric silsesquioxane nano-atom

    Science.gov (United States)

    Ren, He

    . In such "bottom-up" approach, the precise fabrication of 2 nm 100 nm nanostructures, is of great research interest. In this thesis, crystal engineering of giant molecules based on PDI conjugated POSS Nano-Atom (PDI-BPOSS) nano-atoms via self-assembly is performed and studied. Herein, three different giant molecules were synthesized: shape amphiphile, m-phenyl-(PDI-BPOSS)2 (S1) and tetrahedron, R-(PDI-BPOSS)4 (S2) and S-(PDI-BPOSS)4 (S3). Single crystals were grown for S1 and S2, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and transmission electron microscopy (TEM) were performed, and crystal structures of these samples were determined, while hexagonal superlattice without crystal order can be observed for S3 to exhibit crystal-like morphology.

  10. ABUNDANCES IN THE LOCAL REGION. I. G AND K GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Luck, R. Earle, E-mail: rel2@case.edu [Department of Astronomy, Case Western Reserve University 10900 Euclid Avenue, Cleveland, OH 44106-7215 (United States)

    2015-09-15

    Parameters and abundances for 1133 stars of spectral types F, G, and K of luminosity class III have been derived. In terms of stellar parameters, the primary point of interest is the disagreement between gravities derived with masses determined from isochrones, and gravities determined from an ionization balance. This is not a new result per se, but the size of this sample emphasizes the severity of the problem. A variety of arguments led to the selection of the ionization-balance gravity as the working value. The derived abundances indicate that the giants in the solar region have Sun-like total abundances and abundance ratios. Stellar evolution indicators have also been investigated with the Li abundances and the [C/Fe] and C/O ratios, indicating that standard processing has been operating in these stars. The more salient result for stellar evolution is that the [C/Fe] data across the red-giant clump indicates the presence of mass-dependent mixing in accord with standard stellar evolution predictions.

  11. MULTIPLE OUTFLOWS IN THE GIANT ERUPTION OF A MASSIVE STAR

    Energy Technology Data Exchange (ETDEWEB)

    Humphreys, Roberta M.; Gordon, Michael S.; Jones, Terry J. [Minnesota Institute for Astrophysics, 116 Church St. SE, University of Minnesota, Minneapolis, MN 55455 (United States); Martin, John C., E-mail: roberta@umn.edu [University of Illinois Springfield, Springfield, IL 62703 (United States)

    2016-08-01

    The supernova impostor PSN J09132750+7627410 in NGC 2748 reached a maximum luminosity of ≈−14 mag. It was quickly realized that it was not a true supernova, but another example of a nonterminal giant eruption. PSN J09132750+7627410 is distinguished by multiple P Cygni absorption minima in the Balmer emission lines that correspond to outflow velocities of −400, −1100, and −1600 km s{sup −1}. Multiple outflows have been observed in only a few other objects. In this paper we describe the evolution of the spectrum and the P Cygni profiles for 3 months past maximum, the post-maximum formation of a cool, dense wind, and the identification of a possible progenitor. One of the possible progenitors is an infrared source. Its pre-eruption spectral energy distribution suggests a bolometric luminosity of −8.3 mag and a dust temperature of 780 K. If it is the progenitor, it is above the AGB limit, unlike the intermediate-luminosity red transients. The three P Cygni profiles could be due to ejecta from the current eruption, the wind of the progenitor, or previous mass-loss events. We suggest that they were all formed as part of the same high-mass-loss event and are due to material ejected at different velocities or energies. We also suggest that multiple outflows during giant eruptions may be more common than reported.

  12. Spectroscopy of chromospheric lines of giants in the globular cluster

    Science.gov (United States)

    Dupree, A. K.; Hartmann, Lee; Smith, Graeme H.; Rodgers, A. W.; Roberts, W. H.; Zucker, D. B.

    1994-01-01

    Spectroscopic observations of chromospheric transitions (Mg II, H-alpha, and Ca II K) from two red giants (A31 and A59) in the globular cluster NGC 6572 were made with the Goddard High Resolution Spectrograph on the Hubble Space Telescope and the coude spectrograph of the 1.9 m telescope at the Mount Stromlo Observatory. These measurements give evidence for chromospheric activity and outward motions within the atmospheres. The surface flux of the Mg II emission is comparable to that in disk population giants of similar (B-V) color. The Mg II profiles are asymmetric, which is most likely caused by absorption in an expanding stellar atmosphere and/or by possible interstellar features. Notches are found in the core of the H-alpha line of A59, which are similar to those found in Cepheids. This suggests that shocks are present in the atmosphere of A59 and indicates that hydrodynamic phenomena are influencing the levvel of chromospheric emission and producing upper atmospheric motions which may lead to mass loss.

  13. Nearly suppressed photoluminescence blinking of small-sized, blue-green-orange-red emitting single CdSe-based core/gradient alloy shell/shell quantum dots: correlation between truncation time and photoluminescence quantum yield.

    Science.gov (United States)

    Roy, Debjit; Mandal, Saptarshi; De, Chayan K; Kumar, Kaushalendra; Mandal, Prasun K

    2018-04-18

    CdSe-based core/gradient alloy shell/shell semiconductor quantum dots (CGASS QDs) have been shown to be optically quite superior compared to core-shell QDs. However, very little is known about CGASS QDs at the single particle level. Photoluminescence blinking dynamics of four differently emitting (blue (λem = 510), green (λem = 532), orange (λem = 591), and red (λem = 619)) single CGASS QDs having average sizes 600 nm). In this manuscript, we report nearly suppressed PL blinking behaviour of CGASS QDs with average sizes correlation between the event durations and found that residual memory exists in both the ON- and OFF-event durations. Positively correlated successive ON-ON and OFF-OFF event durations and negatively correlated (anti-correlated) ON-OFF event durations perhaps suggest the involvement of more than one type of trapping process within the blinking framework. The timescale corresponding to the additional exponential term has been assigned to hole trapping for ON-event duration statistics. Similarly, for OFF-event duration statistics, this component suggests hole detrapping. We found that the average duration of the exponential process for the ON-event durations is an order of magnitude higher than that of the OFF-event durations. This indicates that the holes are trapped for a significantly long time. When electron trapping is followed by such a hole trapping, long ON-event durations result. We have observed long ON-event durations, as high as 50 s. The competing charge tunnelling model has been used to account for the observed blinking behaviour in these CGASS QDs. Quite interestingly, the PLQY of all of these differently emitting QDs (an ensemble level property) could be correlated with the truncation time (a property at the single particle level). A respective concomitant increase-decrease of ON-OFF event truncation times with increasing PLQY is also indicative of a varying degree of suppression of the Auger recombination processes in these four

  14. Formation of Ice Giant Satellites During Thommes Model Mirgration

    Science.gov (United States)

    Fuse, Christopher; Spiegelberg, Josephine

    2018-01-01

    Inconsistencies between ice giant planet characteristics and classic planet formation theories have led to a re-evaluation of the formation of the outer Solar system. Thommes model migration delivers proto-Uranus and Neptune from orbits interior to Saturn to their current locations. The Thommes model has also been able to reproduce the large Galilean and Saturnian moons via interactions between the proto-ice giants and the gas giant moon disks.As part of a series of investigations examining the effects of Thommes model migration on the formation of moons, N-body simulations of the formation of the Uranian and Neptunian satellite systems were performed. Previous research has yielded conflicting results as to whether satellite systems are stable during planetary migration. Some studies, such as Beaugé (2002) concluded that the system was not stable over the proposed duration of migration. Conversely, Fuse and Neville (2011) and Yokoyama et al. (2011) found that moons were retained, though the nature of the resulting system was heavily influenced by interactions with planetesimals and other large objects. The results of the current study indicate that in situ simulations of the Uranus and Neptune systems can produce stable moons. Whether with current orbital parameters or located at pre-migration, inner Solar system semi-major axes, the simulations end with 5.8 ± 0.15 or 5.9 ± 0.7 regular satellites around Uranus and Neptune, respectively. Preliminary simulations of a proto-moon disk around a single planet migrating via the Thommes model have failed to retain moons. Furthermore, simulations of ejection of the current Uranian satellite system retained at most one moon. Thus, for the Thommes model to be valid, it is likely that moon formation did not begin until after migration ended. Future work will examine the formation of gas and ice giant moons through other migration theories, such as the Nice model (Tsiganis et al. 2006).

  15. Flea (Pulex simulans) infestation in captive giant anteaters (Myrmecophaga tridactyla).

    Science.gov (United States)

    Mutlow, Adrian G; Dryden, Michael W; Payne, Patricia A

    2006-09-01

    A pair of captive adult giant anteaters (Myrmecophaga tridactyla) presented heavily infested with a flea species (Pulex simulans) commonly found on Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor) in the central United States. In this case, the flea was demonstrated to have completed its entire life cycle with the anteaters as the host. A single treatment of topical imidacloprid, coupled with removal and replacement of infested bedding, was rapidly effective at controlling the infestation and no adverse effects of the drug were noted. Control of the anteater infestation also removed the flea infestation of aardvarks in the same building.

  16. Analysis of the static yield stress for giant electrorheological fluids

    Science.gov (United States)

    Seo, Youngwook P.; Choi, Hyoung Jin; Seo, Yongsok

    2017-08-01

    Cheng et al. (2010)'s experimental results for the static yield stress of giant electrorheological (GER) fluids over the full range of electric field strengths were reanalyzed by applying Seo's scaling function which could include both the polarization and the conductivity models. The Seo's scaling function could correctly fit the yield stress behavior of GER suspensions behavior after if a proper normalization of the yield stress data was taken which collapse them onto a single curve. The model predictions were also contrasted with recently proposed Choi et al.'s scaling function to rouse the attention for a proper consideration of the GER fluid mechanisms.

  17. Electromagnetic decay of giant resonances

    International Nuclear Information System (INIS)

    Beene, J.R.; Bertrand, F.E.; Halbert, M.L.; Auble, R.L.; Hensley, D.C.; Horen, D.J.; Robinson, R.L.; Sayer, R.O.; Sjoreen, T.P.

    1985-01-01

    Coincidence experiments are carried out to investigate the photon and neutron emission from the giant resonance regions of 208 Pb and 90 Zr using the ORNL Spin Spectrometer, a 72-segment NaI detector system. The authors determined the total gamma-decay probability, the ground-state gamma branching ratio, and the branching ratios to a number of low-lying states as a function of excitation energy in 208 Pb to ∼15 MeV. Similar data were also obtained on 90 Zr. The total yield of ground-state E2 gamma radiation in 208 Pb and the comparative absence of such radiation in 90 Zr can only be understood if decay of compound (damped) states is considered. (Auth.)

  18. Giant trichobezoar mimicking gastric tumour

    International Nuclear Information System (INIS)

    Ali, S.A.; Soomro, A.G.; Jarwar, M.; Memon, A.S.; Siddiqui, A.J.

    2012-01-01

    We present a case of giant gastric trichobezoar retrieved through a long gastrotomy in a 40 years old married women from rural Sindh with unreported psychological disturbance. Trichobezoar almost exclusively occur in females with an underlying psychiatric disorder. It has an insidious development of symptoms which accounts for its delayed presentation and large size at the time of diagnosis. They are associated with trichophagia (habit of compulsive hair eating) and are usually diagnosed on CT Scans or upper GI Endoscopy. They can give rise to complications like gastro-duodenal ulceration, haemorrhage, perforation, peritonitis or obstruction with a high rate of mortality. The treatment is endoscopic, laparoscopic or surgical removal and usually followed by psychiatric opinion. (author)

  19. Giant Congenital Melanocytic Naevi: review of literature

    Directory of Open Access Journals (Sweden)

    A. Marchesi

    2012-04-01

    Full Text Available giant congenital pigmented naevi is a great reconstructive challenge for the pediatric and plastic surgeons. due to the increased risk of malignant transformation in such lesions, many procedures have been used to remove giant congenital naevi like dermoabrasion, laser treatment or surgical excision combined with reconstruction through skin expansion or skin grafting; among these, only a complete excision can offer an efficacious treatment. in our centre we use the “tissue expansion” technique in order to achieve a sufficient quantity of normal skin to perform a both staged and radical excision of these giant lesions.

  20. Multipole giant resonances in highly excited nuclei

    International Nuclear Information System (INIS)

    Xia Keding; Cai Yanhuang

    1989-01-01

    The isoscalar giant surface resonance and giant dipole resonance in highly excited nuclei are discussed. Excitation energies of the giant modes in 208 Pb are calculated in a simplified model, using the concept of energy wieghted sum rule (EWSR), and the extended Thomas-Fermi approximation at the finite temperature is employed to describe the finite temperature is employed to describe the finite temperature equilibrium state. It is shown that EWSR and the energy of the resonance depend only weakly on temperature in the system. This weak dependence is analysed

  1. Giant cell arteritis of fallopian tube.

    Science.gov (United States)

    Azzena, A; Altavilla, G; Salmaso, R; Vasoin, F; Pellizzari, P; Doria, A

    1994-01-01

    One case of giant cells arteritis involving tubaric arteries in a postmenopausal woman is described. The patient was 59 years old and presented with asthenia, anemia, fever, weight loss, an abdominal palpable mass and elevated erythrocyte sedimentation rate. Exploratory laparotomy revealed a large ovarian cyst of 14 cm in diameter. Extensive giant cell arteritis, Horton's type, of the small-sizes arteries was found unexpectedly in the fallopian tube of the patient who had had a prior ovariectomy. Giant cell arteritis of the female genital tract is a rare finding in elderly women and may occur as an isolated finding or as part of generalised arteritis.

  2. Electromagnetic transitions between giant resonances within a continuum-RPA approach

    NARCIS (Netherlands)

    Rodin, VA; Dieperink, AEL

    2002-01-01

    A general continuum-RPA approach is developed to describe electromagnetic transitions between giant resonances. Using a diagrammatic representation for the three-point Green's function, an expression for the transition amplitude is derived which allows one to incorporate effects of mixing of single

  3. On the nature of giant lubbles of the Cygnus X source type

    International Nuclear Information System (INIS)

    Silich, S.A.; Fomin, P.A.

    1984-01-01

    An observational criterion for selecting between two models (single supernova explosion or supernova cascade process) of the origin of giant bubbles of the Cygnus X source type is proposed. It is based on qualitative difference of x-ray radial brightness distribution in these two cases

  4. Dilute oxalic acid pretreatment for biorefining giant reed (Arundo donax L.)

    Science.gov (United States)

    Danilo Scordia; Salvatore L. Cosentino; Jae-Won Lee; Thomas W. Jeffries

    2011-01-01

    Biomass pretreatment is essential to overcome recalcitrance of lignocellulose for ethanol production. In the present study we pretreated giant reed (Arundo donax L.), a perennial, rhizomatous lignocellulosic grass with dilute oxalic acid. The effects of temperature (170-190 ºC), acid loading (2-10% w/w) and reaction time (15-40 min) were handled as a single...

  5. Giant nonlinear interaction between two optical beams via a quantum dot embedded in a photonic wire

    DEFF Research Database (Denmark)

    Nguyen, H.A.; Grange, T.; Reznychenko, B.

    2018-01-01

    a tailored photonic environment. Here, we demonstrate a two-mode giant nonlinearity with a single semiconductor quantum dot (QD) embedded in a photonic wire antenna. We exploit two detuned optical transitions associated with the exciton-biexciton QD level scheme. Owing to the broadband waveguide antenna...

  6. GLOBULAR AND OPEN CLUSTERS OBSERVED BY SDSS/SEGUE: THE GIANT STARS

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Heather L.; Ma, Zhibo; Connor, Thomas; Schechtman-Rook, Andrew; Harding, Paul [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); Clem, James L. [Department of Physics, Grove City College, 100 Campus Dr., Grove City, PA 16127 (United States); An, Deokkeun [Department of Science Education, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Casagrande, Luca [Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, The Australian National University, ACT 2611 (Australia); Rockosi, Constance [UCO/Lick Observatory, University of California, Santa Cruz, 1156 High St., Santa Cruz, CA 95064 (United States); Yanny, Brian [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia IL 60510 (United States); Beers, Timothy C. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46656 (United States); Johnson, Jennifer A. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Schneider, Donald P., E-mail: hlm5@case.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2016-01-15

    We present griz observations for the clusters M92, M13 and NGC 6791 and gr photometry for M71, Be 29 and NGC 7789. In addition we present new membership identifications for all these clusters, which have been observed spectroscopically as calibrators for the Sloan Digital Sky Survey (SDSS)/SEGUE survey; this paper focuses in particular on the red giant branch stars in the clusters. In a number of cases, these giants were too bright to be observed in the normal SDSS survey operations, and we describe the procedure used to obtain spectra for these stars. For M71, we also present a new variable reddening map and a new fiducial for the gr giant branch. For NGC 7789, we derived a transformation from T{sub eff} to g–r for giants of near solar abundance, using IRFM T{sub eff} measures of stars with good ugriz  and 2MASS photometry and SEGUE spectra. The result of our analysis is a robust list of known cluster members with correctly dereddened and (if needed) transformed gr photometry for crucial calibration efforts for SDSS and SEGUE.

  7. Characteristics of cerebrovascular accidents at time of diagnosis in a series of 98 patients with giant cell arteritis.

    Science.gov (United States)

    Zenone, Thierry; Puget, Marie

    2013-12-01

    The objective of this study was to determine the characteristics of cerebrovascular accidents at time of diagnosis in patients with giant cell arteritis. Retrospective data were collected from 98 patients at a single hospital with giant cell arteritis (according to the American College of Rheumatology classification criteria) diagnosed between October 1999 and January 2012. Cerebrovascular accident was found at initial presentation in 6 patients (6.1 %, 95 % CIs 2.3-12.9). Most of them had other symptoms of giant cell arteritis when the disease began. Signs reflecting the involvement of vertebro-basilar territory were present in 3 cases. No other case of cerebrovascular accident was described during the follow-up of patient; particularly no case of cerebrovascular accident occurred once corticosteroid therapy for the treatment of giant cell arteritis had been initiated. No differences in the epidemiologic, clinical and laboratory features at the time of diagnosis between patients who had cerebrovascular accidents and the rest of the giant cell arteritis patients were observed. Prognosis was good in our survey. However, there was no case of bilateral vertebral artery occlusion, a condition associated with poor prognosis. The present study confirms that cerebrovascular accidents may be the initial manifestation of giant cell arteritis, an argument in favor of a direct effect of the vasculitis in the development of cerebrovascular accidents rather than a complication of the corticosteroid therapy. The diagnosis of giant cell arteritis should always be considered in an elderly patient with stroke and an unexplained elevation of inflammatory biomarkers.

  8. A STAR IN THE M31 GIANT STREAM: THE HIGHEST NEGATIVE STELLAR VELOCITY KNOWN

    International Nuclear Information System (INIS)

    Caldwell, Nelson; Kenyon, Scott J.; Morrison, Heather; Harding, Paul; Schiavon, Ricardo; Rose, James A.

    2010-01-01

    We report on a single star, B030D, observed as part of a large survey of objects in M31, which has the unusual radial velocity of -780 km s -1 . Based on details of its spectrum, we find that the star is an F supergiant, with a circumstellar shell. The evolutionary status of the star could be one of a post-main-sequence close binary, a symbiotic nova, or less likely, a post-asymptotic giant branch star, which additional observations could help sort out. Membership of the star in the Andromeda Giant Stream can explain its highly negative velocity.

  9. Red blood cell production

    Science.gov (United States)

    ... bone marrow of bones. Stem cells in the red bone marrow called hemocytoblasts give rise to all of the formed elements in blood. If a hemocytoblast commits to becoming a cell called a proerythroblast, it will develop into a new red blood cell. The formation of a red blood ...

  10. Tests of the Giant Impact Hypothesis

    Science.gov (United States)

    Jones, J. H.

    1998-01-01

    The giant impact hypothesis has gained popularity as a means of explaining a volatile-depleted Moon that still has a chemical affinity to the Earth. As Taylor's Axiom decrees, the best models of lunar origin are testable, but this is difficult with the giant impact model. The energy associated with the impact would be sufficient to totally melt and partially vaporize the Earth. And this means that there should he no geological vestige of Barber times. Accordingly, it is important to devise tests that may be used to evaluate the giant impact hypothesis. Three such tests are discussed here. None of these is supportive of the giant impact model, but neither do they disprove it.

  11. Giant planets. Holweck prize lecture 1982

    Energy Technology Data Exchange (ETDEWEB)

    Hide, R. (Meteorological Office, Bracknell (UK))

    1982-10-01

    The main characteristics of the giant planets, Jupiter and Saturn, are outlined. Studies which have been made of the circulation of their atmospheres, the structure of their interiors and the origin of their magnetic fields are discussed.

  12. Giant Omental Lipoma in a Child

    International Nuclear Information System (INIS)

    Chaudhary, Vikas; Narula, Mahender Kaur; Anand, Rama; Gupta, Isha; Kaur, Gurmeen; Kalra, Kanika

    2011-01-01

    Omental lipomas are extremely rare tumors of childhood. We report a case of solitary giant lipoma of the omentum in a child, successfully managed by complete excision, without any recurrence on follow-up study

  13. AFSC/ABL: Female Giant Grenadier maturity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Giant grenadiers Albatrossia pectoralis are caught as bycatch in deep-sea commercial fisheries in relatively large numbers. The population appears to be stable,...

  14. Giant pubertal prolactinoma: Complete resolution following short ...

    African Journals Online (AJOL)

    2016-04-06

    Apr 6, 2016 ... disappeared in a short time with cabergoline treatment. Key words: ... Hyperprolactinemia may cause impotence and hypogonadism in adult men, and rarely ... safe treatment method for male patients with giant prolactinoma.

  15. Who's working on giant clam culture?

    OpenAIRE

    Vega, M.J.M.

    1990-01-01

    An examination is made of the literature on giant clam (Tridacna ) culture methods induced spawning, larvae, larval and post-larval rearing and socioeconomics. ASFA and the ICLARM library and professional staff collections were used for the search.

  16. [Tissular expansion in giant congenital nevi treatment].

    Science.gov (United States)

    Nguyen Van Nuoi, V; Francois-Fiquet, C; Diner, P; Sergent, B; Zazurca, F; Franchi, G; Buis, J; Vazquez, M-P; Picard, A; Kadlub, N

    2014-08-01

    Surgical management of giant melanotic naevi remains a surgical challenge. Tissue expansion provides tissue of the same quality for the repair of defects. The aim of this study is to review tissular expansion for giant melanotic naevi. We conducted a retrospective study from 2000 to 2012. All children patients who underwent a tissular expansion for giant congenital naevi had been included. Epidemiological data, surgical procedure, complication rate and results had been analysed. Thirty-tree patients had been included; they underwent 61 procedures with 79 tissular-expansion prosthesis. Previous surgery, mostly simple excision had been performed before tissular expansion. Complete naevus excision had been performed in 63.3% of the cases. Complications occurred in 45% of the cases, however in 50% of them were minor. Iterative surgery increased the complication rate. Tissular expansion is a valuable option for giant congenital naevus. However, complication rate remained high, especially when iterative surgery is needed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  17. Surgical treatment for giant incisional hernia

    DEFF Research Database (Denmark)

    Eriksson, A; Rosenberg, J; Bisgaard, T

    2014-01-01

    INTRODUCTION: Repair for giant incisional hernias is a challenge due to unacceptable high morbidity and recurrence rates. Several surgical techniques are available, but all are poorly documented. This systematic review was undertaken to evaluate the existing literature on repair for giant...... % with a wide range between studies of 4-100 %. The mortality ranged from 0 to 5 % (median 0 %) and recurrence rate ranged from 0 to 53 % (median 5 %). Study follow-up ranged from 15 to 97 months (median 36 months). Mesh repair should always be used for patients undergoing repair for a giant hernia......, and the sublay position may have advantages over onlay positioning. To avoid tension, it may be advisable to use a mesh in combination with a component separation technique. Inlay positioning of the mesh and repair without a mesh should be avoided. CONCLUSIONS: Evidence to optimise repair for giant hernias...

  18. Macroscopic description of isoscalar giant multipole resonances

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1980-01-01

    On the basis of a simple macroscopic model, we calculate the isoscalar giant-resonance energy as a function of mass number and multipole degree. The restoring force is determined from the distortion of the Fermi surface, and the inertia is determined for the incompressible, irrotational flow of nucleons with unit effective mass. With no adjustable parameters, the resulting closed expression reproduces correctly the available experimental data, namely the magnitude and dependence upon mass number of the giant quadrupole energy and the magnitude of the giant octupole energy for 208 Pb. We also calculate the isoscalar giant-resonance width as a function of mass number and multipole degree for various macroscopic damping mechanisms, including two-body viscosity, one-body dissipation, and modified one-body dissipation. None of these damping mechanisms reproduces correctly all features of the available experimental data, namely the magnitude and dependence upon mass number of the giant quadrupole width and the magnitude of the giant octupole width for 208 Pb

  19. Swiss roll operation for giant fibroadenoma.

    Science.gov (United States)

    Soomro, Saleem A; Memon, Sohail A; Mohammad, Noor; Maher, Mumtaz

    2009-01-01

    Fibroadenoma 5 cm or more is called giant fibroadenoma. Giant fibroadenoma can distort the shape of breast and causes asymmetry, so it should be excised. There are several techniques for excision of giant fibroadenoma. In our technique we remove them through cosmetically acceptable circumareolar incision to maintain the shape and symmetry of breast. The objectives were to assess the cosmetic results of Swiss roll operation for giant fibroadenoma. The study was conducted for six years from January, 2002 to December, 2007. Seventy patients of giant fibroadenoma were included in this study. They were diagnosed on history and clinical examination supported by ultrasound and postoperative histopathological examination. Data were collected from outpatient department and operation theatre. Swiss roll operation was performed under general anaesthesia. Mean tumor size was 6.38 cm. Three cm and 4 cm incisions were used for tumour 6 cm in size respectively. Skin closed with Vicryl 3/0 subcuticular stitches. Sixteen out of 70 patients had no scar while others hadminimal scar. All patients had normal shape and symmetry of breast. On histopathology fibroadenoma was confirmed. Giant fibroadenoma should be removed through cosmetically acceptable cicumareolar incision especially in unmarried young females who have small breast. Swiss-roll operation is superior in maintaining the shape and symmetry of breast. No major complication was found in our series except seroma formation in 10 patients.

  20. Production of Generation-2 Mekong giant catfish (Pangasinodon gigas cultured with Spirulina sp.

    Directory of Open Access Journals (Sweden)

    Kriangsak Meng-umphan

    2008-11-01

    Full Text Available The purpose of this study is to evaluate the treatment of Spirulina-supplemented pellet feed to 5-year-old F1 groups of Mekong giant catfish (Pangasinodon gigas from the brood stock and intended for use as breeders. The effects on their growth and maturation when cultured in an earthen pond were observed. Results revealed that, compared to control, there was more gain in weight while the feed conversion ratio was lower. The number of red blood cells was also higher while that of white blood cells was lower, compared to control. Out of 18 treated fish (9 males and 9 females, 6 males and 2 females gave sperms and eggs while none from control group did. It was concluded that Spirulina supplemented in pellet feed can improve growth and maturation performance to the brood stock of Mekong giant catfish.

  1. Detection of association and fusion of giant vesicles using a fluorescence-activated cell sorter.

    Science.gov (United States)

    Sunami, Takeshi; Caschera, Filippo; Morita, Yuuki; Toyota, Taro; Nishimura, Kazuya; Matsuura, Tomoaki; Suzuki, Hiroaki; Hanczyc, Martin M; Yomo, Tetsuya

    2010-10-05

    We have developed a method to evaluate the fusion process of giant vesicles using a fluorescence-activated cell sorter (FACS). Three fluorescent markers and FACS technology were used to evaluate the extent of association and fusion of giant vesicles. Two fluorescent markers encapsulated in different vesicle populations were used as association markers; when these vesicles associate, the two independent markers should be observed simultaneously in a single detection event. The quenched fluorescent marker and the dequencher, which were encapsulated in separate vesicle populations, were used as the fusion marker. When the internal aqueous solutions mix, the quenched marker is liberated by the dequencher and emits the third fluorescent signal. Although populations of pure POPC vesicles showed no detectable association or fusion, the same populations, oppositely charged by the exogenous addition of charged amphiphiles, showed up to 50% association and 30% fusion upon population analysis of 100,000 giant vesicles. Although a substantial fraction of the vesicles associated in response to a small amount of the charged amphiphiles (5% mole fraction compared to POPC alone), a larger amount of the charged amphiphiles (25%) was needed to induce vesicle fusion. The present methodology also revealed that the association and fusion of giant vesicles was dependent on size, with larger giant vesicles associating and fusing more frequently.

  2. Structure and direct decay of Giant Monopole Resonances

    International Nuclear Information System (INIS)

    Avez, B.; Simenel, C.

    2013-01-01

    We study structure and direct decay of the Giant Monopole Resonance (GMR) at the Random Phase Approximation (RPA) level using the time-dependent energy density functional method in the linear response regime in a few doubly magic nuclei. A proper treatment of the continuum, through the use of large coordinate space, allows for a separation between the nucleus and its emitted nucleons. The microscopic structure of the GMR is investigated with the decomposition of the strength function into individual single-particle quantum numbers. A similar microscopic decomposition of the spectra of emitted nucleons by direct decay of the GMR is performed. In this harmonic picture of giant resonance, shifting every contribution by the initial single-particle energy allows to reconstruct the GMR strength function. The RPA residual interaction couples bound 1-particle 1-hole states to unbound ones, allowing for the total decay of the GMR. In this article, we then intend to get an understanding of the direct decay mechanism from coherent one-particle-one-hole superpositions, while neglecting more complex configurations. Time-dependent beyond mean-field approaches should be used, in the future, to extend this method. (orig.)

  3. Infiltrating giant cellular blue naevus.

    Science.gov (United States)

    Bittencourt, A L; Monteiro, D A; De Pretto, O J

    2007-01-01

    Cellular blue naevi (CBN) measure 1-2 cm in diameter and affect the dermis, occasionally extending into the subcutaneous fat. The case of a 14-year-old boy with a giant CBN (GCBN) involving the right half of the face, the jugal mucosa and the lower eyelid with a tumour that had infiltrated the bone and the maxillary and ethmoidal sinuses is reported. Biopsies were taken from the skin, jugal mucosa and maxillary sinus. The following markers were used in the immunohistochemical evaluation: CD34, CD56, HMB-45, anti-S100, A-103, Melan A and MIB-1. The biopsy specimens showed a biphasic pattern affecting the lower dermis, subcutaneous fat, skeletal muscle, bone, jugal mucosa and maxillary sinus, but there was no histological evidence of malignancy. The tumour cells were CD34-, CD56-, HMB45+, anti-S100+ and A-103+. Melan A was focally expressed. No positive MIB-1 cells were identified. The present case shows that GCBN may infiltrate deeply, with no evidence of malignancy.

  4. Giant hepatocellular adenoma; case report

    Energy Technology Data Exchange (ETDEWEB)

    Pitella, F.A.; Coutinho, A.M.N.; Coura Filho, G.B.; Costa, P.L.A.; Ono, C.R.; Watanabe, T.; Sapienza, M.T.; Hironaka, F.; Cerri, G.G.; Buchpiguel, C.A. [Universidade de Sao Paulo (FM/USP), SP (Brazil). Inst. de Radiologia. Servico de Medicina Nuclear

    2008-07-01

    Full text: Introduction: Hepatocellular adenoma is a benign hepatic tumor identified mainly in women during fertility age, with estimated incidence of 4/1000 inhabitants. It is usually unique, well circumscribed, with or without a capsule, size varying from 1 to 30 cm, with possible central areas of necrosis and hemorrhage. Case Report: A 37-year-old female patient presenting with no comorbities, use of hormonal birth control pills for 18 years, a condition of reduction in the consistency of feces, increase in number of daily defecations, abdominal cramps, and a stuffed sensation after meals for two years. A palpable abdominal mass extending from the right hypochondriac to the right iliac fossa was noticed four months ago. A computerized tomography (CT) showed an extensive hepatic mass on the right which was considered, within the diagnostic hypotheses, hepatic adenomatosis, without ruling out secondary lesions. A hepatic scintillography with {sup 99m}Tc-DISIDA showed an extensive exophytic area from segment V to the right iliac fossa with arterialized blood flow and hepatocytic activity, as well as a hepatic nodule in segment VII with hepatocytic activity consistent with the hepatic adenomas hypothesis. The biopsy confirmed the hepatic adenoma diagnosis and the patient was submitted to a partial hepatectomy and cholecystectomy with good clinical evolution. Conclusion: Nuclear Medicine may supplement the assessment of hepatic nodules, including giant masses, thus suggesting new hypotheses and direction to therapeutic conduct. (author)

  5. Migration of accreting giant planets

    Science.gov (United States)

    Crida, A.; Bitsch, B.; Raibaldi, A.

    2016-12-01

    We present the results of 2D hydro simulations of giant planets in proto-planetary discs, which accrete gas at a more or less high rate. First, starting from a solid core of 20 Earth masses, we show that as soon as the runaway accretion of gas turns on, the planet is saved from type I migration : the gap opening mass is reached before the planet is lost into its host star. Furthermore, gas accretion helps opening the gap in low mass discs. Consequently, if the accretion rate is limited to the disc supply, then the planet is already inside a gap and in type II migration. We further show that the type II migration of a Jupiter mass planet actually depends on its accretion rate. Only when the accretion is high do we retrieve the classical picture where no gas crosses the gap and the planet follows the disc spreading. These results impact our understanding of planet migration and planet population synthesis models. The e-poster presenting these results in French can be found here: L'e-poster présentant ces résultats en français est disponible à cette adresse: http://sf2a.eu/semaine-sf2a/2016/posterpdfs/156_179_49.pdf.

  6. The Giant Planet Satellite Exospheres

    Science.gov (United States)

    McGrath, Melissa A.

    2014-01-01

    Exospheres are relatively common in the outer solar system among the moons of the gas giant planets. They span the range from very tenuous, surface-bounded exospheres (e.g., Rhea, Dione) to quite robust exospheres with exobase above the surface (e.g., lo, Triton), and include many intermediate cases (e.g., Europa, Ganymede, Enceladus). The exospheres of these moons exhibit an interesting variety of sources, from surface sputtering, to frost sublimation, to active plumes, and also well illustrate another common characteristic of the outer planet satellite exospheres, namely, that the primary species often exists both as a gas in atmosphere, and a condensate (frost or ice) on the surface. As described by Yelle et al. (1995) for Triton, "The interchange of matter between gas and solid phases on these bodies has profound effects on the physical state of the surface and the structure of the atmosphere." A brief overview of the exospheres of the outer planet satellites will be presented, including an inter-comparison of these satellites exospheres with each other, and with the exospheres of the Moon and Mercury.

  7. The giant branch of omega Centauri. I. Abundance variations due to mixing

    International Nuclear Information System (INIS)

    Bessell, M.S.; Norris, J.

    1976-01-01

    David Dunlap Observatory (DDO) intermediate-band and RI photometry, together with low-dispersion spectra of a representative sample of stars on the upper giant branch were analysed. Several conclusions were: i) The large width of the giant branch is inseparably connected with mixing. All stars on the red side of the upper giant branch appear to have greatly enhanced features of the CN molecule, with no comparable enhancement of [Fe/H]. ii) A positive correlation between [Fe/H] and the CN excess deltaC (41--42) exists in ω Cen similar to that reported by McClure and Norris for NGC 362. We suggest that this can be explained by the effect of the strong CN band at lambda3800 on the 38 filter of the DDO system. A broad continuum depression around lambda4000 exists in the mixed stars and may also contribute to the correlation. iii) The stars on the blue side of the giant branch show no evidence for mixing and yield an abundance [Fe/H]=-2.1 +- 0.2. It appears that the material from which the cluster formed was as metal deficient as the very metal poor globular clusters. iv) The strong CN enhancement in stars on the red side of the giant branch is not accompanied by greatly enhanced features of CH and C 2 as found in the CH stars. We suggest that the CN stars have O/C>1 and that during the mixing process much of the material now seen at the surface of these objects has been processed through the CN cycle. v) The large width of the branch seen in the (V, B--V) -plane is greatly reduced in the (R, R--I) -plane. This suggests to us that blocking effects are predominant in causing the observed spread in (B--V). We consider the problem that ω Cen is apparently unique in possessing an anomalously wide giant branch. We investigate the possibility that the effect could result from anomalously large angular momentum, and suggest that it might be profitable to observe the highly flattened cluster NGC 6273 to ascertain if it exhibits the same phenomenon

  8. YOUNG SOLAR SYSTEM's FIFTH GIANT PLANET?

    International Nuclear Information System (INIS)

    Nesvorný, David

    2011-01-01

    Studies of solar system formation suggest that the solar system's giant planets formed and migrated in the protoplanetary disk to reach the resonant orbits with all planets inside ∼15 AU from the Sun. After the gas disk's dispersal, Uranus and Neptune were likely scattered by the gas giants, and approached their current orbits while dispersing the transplanetary disk of planetesimals, whose remains survived to this time in the region known as the Kuiper Belt. Here we performed N-body integrations of the scattering phase between giant planets in an attempt to determine which initial states are plausible. We found that the dynamical simulations starting with a resonant system of four giant planets have a low success rate in matching the present orbits of giant planets and various other constraints (e.g., survival of the terrestrial planets). The dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, and leads to final systems with fewer than four planets. Several initial states stand out in that they show a relatively large likelihood of success in matching the constraints. Some of the statistically best results were obtained when assuming that the solar system initially had five giant planets and one ice giant, with the mass comparable to that of Uranus and Neptune, and which was ejected to interstellar space by Jupiter. This possibility appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, which indicates that planet ejection should be common.

  9. Young Solar System's Fifth Giant Planet?

    Science.gov (United States)

    Nesvorný, David

    2011-12-01

    Studies of solar system formation suggest that the solar system's giant planets formed and migrated in the protoplanetary disk to reach the resonant orbits with all planets inside ~15 AU from the Sun. After the gas disk's dispersal, Uranus and Neptune were likely scattered by the gas giants, and approached their current orbits while dispersing the transplanetary disk of planetesimals, whose remains survived to this time in the region known as the Kuiper Belt. Here we performed N-body integrations of the scattering phase between giant planets in an attempt to determine which initial states are plausible. We found that the dynamical simulations starting with a resonant system of four giant planets have a low success rate in matching the present orbits of giant planets and various other constraints (e.g., survival of the terrestrial planets). The dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, and leads to final systems with fewer than four planets. Several initial states stand out in that they show a relatively large likelihood of success in matching the constraints. Some of the statistically best results were obtained when assuming that the solar system initially had five giant planets and one ice giant, with the mass comparable to that of Uranus and Neptune, and which was ejected to interstellar space by Jupiter. This possibility appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, which indicates that planet ejection should be common.

  10. Fast Winds and Mass Loss from Metal-Poor Field Giants

    Science.gov (United States)

    Dupree, A. K.; Smith, Graeme H.; Strader, Jay

    2009-11-01

    Echelle spectra of the infrared He I λ10830 line were obtained with NIRSPEC on the Keck 2 telescope for 41 metal-deficient field giant stars including those on the red giant branch (RGB), asymptotic giant branch (AGB), and red horizontal branch (RHB). The presence of this He I line is ubiquitous in stars with T effgsim 4500 K and MV fainter than -1.5, and reveals the dynamics of the atmosphere. The line strength increases with effective temperature for T effgsim 5300 K in RHB stars. In AGB and RGB stars, the line strength increases with luminosity. Fast outflows (gsim 60 km s-1) are detected from the majority of the stars and about 40% of the outflows have sufficient speed as to allow escape of material from the star as well as from a globular cluster. Outflow speeds and line strengths do not depend on metallicity for our sample ([Fe/H]= -0.7 to -3.0), suggesting the driving mechanism for these winds derives from magnetic and/or hydrodynamic processes. Gas outflows are present in every luminous giant, but are not detected in all stars of lower luminosity indicating possible variability. Mass loss rates ranging from ~3 × 10-10 to ~6 × 10-8 M sun yr-1 estimated from the Sobolev approximation for line formation represent values with evolutionary significance for red giants and RHB stars. We estimate that 0.2 M sun will be lost on the RGB, and the torque of this wind can account for observations of slowly rotating RHB stars in the field. About 0.1-0.2 M sun will be lost on the RHB itself. This first empirical determination of mass loss on the RHB may contribute to the appearance of extended horizontal branches in globular clusters. The spectra appear to resolve the problem of missing intracluster material in globular clusters. Opportunities exist for "wind smothering" of dwarf stars by winds from the evolved population, possibly leading to surface pollution in regions of high stellar density. Data presented herein were obtained at the W. M. Keck Observatory, which

  11. Stability of a giant connected component in a complex network

    Science.gov (United States)

    Kitsak, Maksim; Ganin, Alexander A.; Eisenberg, Daniel A.; Krapivsky, Pavel L.; Krioukov, Dmitri; Alderson, David L.; Linkov, Igor

    2018-01-01

    We analyze the stability of the network's giant connected component under impact of adverse events, which we model through the link percolation. Specifically, we quantify the extent to which the largest connected component of a network consists of the same nodes, regardless of the specific set of deactivated links. Our results are intuitive in the case of single-layered systems: the presence of large degree nodes in a single-layered network ensures both its robustness and stability. In contrast, we find that interdependent networks that are robust to adverse events have unstable connected components. Our results bring novel insights to the design of resilient network topologies and the reinforcement of existing networked systems.

  12. NON-RADIAL OSCILLATIONS IN M-GIANT SEMI-REGULAR VARIABLES: STELLAR MODELS AND KEPLER OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Stello, Dennis; Compton, Douglas L.; Bedding, Timothy R.; Kiss, Laszlo L.; Bellamy, Beau [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); García, Rafael A. [Laboratoire AIM, CEA/DSM-CNRS, Université Paris 7 Diderot, IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Mathur, Savita, E-mail: stello@physics.usyd.edu.au [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States)

    2014-06-10

    The success of asteroseismology relies heavily on our ability to identify the frequency patterns of stellar oscillation modes. For stars like the Sun this is relatively easy because the mode frequencies follow a regular pattern described by a well-founded asymptotic relation. When a solar-like star evolves off the main sequence and onto the red giant branch its structure changes dramatically, resulting in changes in the frequency pattern of the modes. We follow the evolution of the adiabatic frequency pattern from the main sequence to near the tip of the red giant branch for a series of models. We find a significant departure from the asymptotic relation for the non-radial modes near the red giant branch tip, resulting in a triplet frequency pattern. To support our investigation we analyze almost four years of Kepler data of the most luminous stars in the field (late K and early M type) and find that their frequency spectra indeed show a triplet pattern dominated by dipole modes even for the most luminous stars in our sample. Our identification explains previous results from ground-based observations reporting fine structure in the Petersen diagram and sub-ridges in the period-luminosity diagram. Finally, we find ''new ridges'' of non-radial modes with frequencies below the fundamental mode in our model calculations, and we speculate they are related to f modes.

  13. Cannibal Stars Cause Giant Explosions in Fornax Cluster Galaxy

    Science.gov (United States)

    2000-07-01

    been necessary to detect a few distant novae [3]. VLT observations of NGC 1316 in the Fornax Cluster ESO PR Photo 18a/00 ESO PR Photo 18a/00 [Preview - JPEG: 400 x 448 pix - 28k] [Normal - JPEG: 800 x 895 pix - 136k] [Full-Res - JPEG: 1941 x 2172 pix - 904k] Caption : Colour composite photo of the central area of NGC 1316 , a giant elliptical galaxy in the Fornax cluster of galaxies. Many dark dust clouds and lanes are visible. Some of the star-like objects in the field are globular clusters of stars that belong to the galaxy. It is based on CCD exposures, obtained with the 8.2-m VLT/ANTU telescope and the FORS-1 multi-mode instrument through B (blue), V (green-yellow) and I (here rendered as red) filters, respectively. The "pyramids" above and below the bright centre of the galaxy and the vertical lines at some of the brighter stars are caused by overexposure ("CCD bleeding"). The field measures 6.8 x 6.8 arcmin 2 , with 0.2 arcsec/pixel. The image quality of this composite is about 0.9 arcsec. North is up and East is left. NGC 1316 is a giant "dusty" galaxy ( PR Photo 18a/00 ), located in the Fornax cluster seen in the southern constellation of that name ("The Oven"). This galaxy is of special interest in connection with current attempts to establish an accurate distance scale in the Universe. In 1980 and 1981, NGC 1316 was the host of two supernovae of type Ia , a class of object that is widely used as a "cosmological standard candle" to determine the distance to very distant galaxies, cf. ESO PR 21/98. A precise measurement of the distance to NGC 1316 may therefore provide an independent calibration of the intrinsic brightness of these supernovae. The new observations were performed during 8 nights distributed over the period from January 9 to 19, 2000. They were made in service mode at the 8.2-m VLT/ANTU telescope with the FORS-1 multi-mode instrument, using a 2k x 2k CCD camera with 0.2 arcsec pixels and a field of 6.8 x 6.8 arcmin 2. The exposures lasted 20 min

  14. Mediterranean salt giants beyond the evaporite model: The Sicily perspective

    Science.gov (United States)

    Carmelo Manuella, Fabio; Scribano, Vittorio; Carbone, Serafina; Hovland, Martin; Johnsen, Hans-Konrad; Rueslåtten, Håkon

    2017-04-01

    Mediterranean salt giants, occurring both in sub-seafloor and in onshore settings (the "Gessoso Solfifera Group"), are traditionally explained by repeated cycles of desiccation and replenishment of the entire basin. However, such hypotheses are strongly biased by mass balance calculations and geodynamic considerations. In addition, any hypothesis without full desiccation, still based on the evaporite model, should consider that seawater brines start to precipitate halite when 2/3 of the seawater has evaporated, and hence the level of the basin cannot be the same as the adjacent ocean. On the other hand, hydrothermal venting of hot saline brines onto the seafloor can precipitate salt in a deep marine basin if a layer of heavy brine exists along the seafloor. This process, likely related to sub-surface boiling or supercritical out-salting (Hovland et al., 2006), is consistent with geological evidence in the Red Sea "Deeps" (Hovland et al., 2015). Although supercritical out-salting and phase separation can sufficiently explain the formation of several marine salt deposits, even in deep marine settings, the Mediterranean salt giant formations can also be explained by the serpentinization model (Scribano et al., 2016). Serpentinization of abyssal peridotites does not involve seawater salts, and large quantities of saline brines accumulate in pores and fractures of the sub-seafloor serpentinites. If these rocks undergo thermal dehydration, for example, due to igneous intrusions, brines and salt slurries can migrate upwards as hydrothermal plumes, eventually venting at the seafloor, giving rise to giant salt deposits over time. These hydrothermal processes can take place in a temporal sequence, as it occurred in the "Caltanissetta Basin" (Sicily). There, salt accumulation associated with serpentinization started during Triassic times (and even earlier), and venting of heavy brines onto the seafloor eventually occurred in the Messinian via the hydrothermal plume mechanism

  15. RADIAL VELOCITY OBSERVATIONS AND LIGHT CURVE NOISE MODELING CONFIRM THAT KEPLER-91b IS A GIANT PLANET ORBITING A GIANT STAR

    International Nuclear Information System (INIS)

    Barclay, Thomas; Huber, Daniel; Rowe, Jason F.; Quintana, Elisa V.; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Foreman-Mackey, Daniel

    2015-01-01

    Kepler-91b is a rare example of a transiting hot Jupiter around a red giant star, providing the possibility to study the formation and composition of hot Jupiters under different conditions compared to main-sequence stars. However, the planetary nature of Kepler-91b, which was confirmed using phase-curve variations by Lillo-Box et al., was recently called into question based on a re-analysis of Kepler data. We have obtained ground-based radial velocity observations from the Hobby-Eberly Telescope and unambiguously confirm the planetary nature of Kepler-91b by simultaneously modeling the Kepler and radial velocity data. The star exhibits temporally correlated noise due to stellar granulation which we model as a Gaussian Process. We hypothesize that it is this noise component that led previous studies to suspect Kepler-91b to be a false positive. Our work confirms the conclusions presented by Lillo-Box et al. that Kepler-91b is a 0.73 ± 0.13 M Jup planet orbiting a red giant star

  16. Coupling single emitters to quantum plasmonic circuits

    DEFF Research Database (Denmark)

    Huck, Alexander; Andersen, Ulrik Lund

    2016-01-01

    In recent years, the controlled coupling of single-photon emitters to propagating surface plasmons has been intensely studied, which is fueled by the prospect of a giant photonic nonlinearity on a nanoscaled platform. In this article, we will review the recent progress on coupling single emitters...

  17. Electrodynamics on extrasolar giant planets

    Energy Technology Data Exchange (ETDEWEB)

    Koskinen, T. T.; Yelle, R. V. [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721-0092 (United States); Lavvas, P. [Groupe de Spectroscopie Moléculaire et Atmosphérique UMR CNRS 7331, Université Reims Champagne-Ardenne, F-51687 Reims (France); Cho, J. Y-K., E-mail: tommi@lpl.arizona.edu [Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)

    2014-11-20

    Strong ionization on close-in extrasolar giant planets (EGPs) suggests that their atmospheres may be affected by ion drag and resistive heating arising from wind-driven electrodynamics. Recent models of ion drag on these planets, however, are based on thermal ionization only and do not include the upper atmosphere above the 1 mbar level. These models are also based on simplified equations of resistive magnetohydrodynamics that are not always valid in extrasolar planet atmospheres. We show that photoionization dominates over thermal ionization over much of the dayside atmosphere above the 100 mbar level, creating an upper ionosphere dominated by ionization of H and He and a lower ionosphere dominated by ionization of metals such as Na, K, and Mg. The resulting dayside electron densities on close-in exoplanets are higher than those encountered in any planetary ionosphere of the solar system, and the conductivities are comparable to the chromosphere of the Sun. Based on these results and assumed magnetic fields, we constrain the conductivity regimes on close-in EGPs and use a generalized Ohm's law to study the basic effects of electrodynamics in their atmospheres. We find that ion drag is important above the 10 mbar level where it can also significantly alter the energy balance through resistive heating. Due to frequent collisions of the electrons and ions with the neutral atmosphere, however, ion drag is largely negligible in the lower atmosphere below the 10 mbar level for a reasonable range of planetary magnetic moments. We find that the atmospheric conductivity decreases by several orders of magnitude in the night side of tidally locked planets, leading to a potentially interesting large-scale dichotomy in electrodynamics between the day and night sides. A combined approach that relies on UV observations of the upper atmosphere, phase curve and Doppler measurements of global dynamics, and visual transit observations to probe the alkali metals can potentially

  18. Hidden values in bauxite residue (red mud): Recovery of metals

    International Nuclear Information System (INIS)

    Liu, Yanju; Naidu, Ravi

    2014-01-01

    Highlights: • Current iron recovery techniques using red mud are depicted. • Advantages and disadvantages exist in different recovering processes. • Economic and environmental friendly integrated usage of red mud is promising. - Abstract: Bauxite residue (red mud) is a hazardous waste generated from alumina refining industries. Unless managed properly, red mud poses significant risks to the local environment due to its extreme alkalinity and its potential impacts on surface and ground water quality. The ever-increasing generation of red mud poses significant challenges to the aluminium industries from management perspectives given the low proportion that are currently being utilized beneficially. Red mud, in most cases, contains elevated concentrations of iron in addition to aluminium, titanium, sodium and valuable rare earth elements. Given the scarcity of iron supply globally, the iron content of red mud has attracted increasing research interest. This paper presents a critical overview of the current techniques employed for iron recovery from red mud. Information on the recovery of other valuable metals is also reviewed to provide an insight into the full potential usage of red mud as an economic resource rather than a waste. Traditional hydrometallurgy and pyrometallurgy are being investigated continuously. However, in this review several new techniques are introduced that consider the process of iron recovery from red mud. An integrated process which can achieve multiple additional values from red mud is much preferred over the single process methods. The information provided here should help to improve the future management and utilization of red mud

  19. Hidden values in bauxite residue (red mud): Recovery of metals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanju; Naidu, Ravi, E-mail: ravi.naidu@unisa.edu.au

    2014-12-15

    Highlights: • Current iron recovery techniques using red mud are depicted. • Advantages and disadvantages exist in different recovering processes. • Economic and environmental friendly integrated usage of red mud is promising. - Abstract: Bauxite residue (red mud) is a hazardous waste generated from alumina refining industries. Unless managed properly, red mud poses significant risks to the local environment due to its extreme alkalinity and its potential impacts on surface and ground water quality. The ever-increasing generation of red mud poses significant challenges to the aluminium industries from management perspectives given the low proportion that are currently being utilized beneficially. Red mud, in most cases, contains elevated concentrations of iron in addition to aluminium, titanium, sodium and valuable rare earth elements. Given the scarcity of iron supply globally, the iron content of red mud has attracted increasing research interest. This paper presents a critical overview of the current techniques employed for iron recovery from red mud. Information on the recovery of other valuable metals is also reviewed to provide an insight into the full potential usage of red mud as an economic resource rather than a waste. Traditional hydrometallurgy and pyrometallurgy are being investigated continuously. However, in this review several new techniques are introduced that consider the process of iron recovery from red mud. An integrated process which can achieve multiple additional values from red mud is much preferred over the single process methods. The information provided here should help to improve the future management and utilization of red mud.

  20. A GIANT SAMPLE OF GIANT PULSES FROM THE CRAB PULSAR

    International Nuclear Information System (INIS)

    Mickaliger, M. B.; McLaughlin, M. A.; Lorimer, D. R.; Palliyaguru, N.; Langston, G. I.; Bilous, A. V.; Kondratiev, V. I.; Lyutikov, M.; Ransom, S. M.

    2012-01-01

    We observed the Crab pulsar with the 43 m telescope in Green Bank, WV over a timespan of 15 months. In total we obtained 100 hr of data at 1.2 GHz and seven hours at 330 MHz, resulting in a sample of about 95,000 giant pulses (GPs). This is the largest sample, to date, of GPs from the Crab pulsar taken with the same telescope and backend and analyzed as one data set. We calculated power-law fits to amplitude distributions for main pulse (MP) and interpulse (IP) GPs, resulting in indices in the range of 2.1-3.1 for MP GPs at 1.2 GHz and in the range of 2.5-3.0 and 2.4-3.1 for MP and IP GPs at 330 MHz. We also correlated the GPs at 1.2 GHz with GPs from the Robert C. Byrd Green Bank Telescope (GBT), which were obtained simultaneously at a higher frequency (8.9 GHz) over a span of 26 hr. In total, 7933 GPs from the 43 m telescope at 1.2 GHz and 39,900 GPs from the GBT were recorded during these contemporaneous observations. At 1.2 GHz, 236 (3%) MP GPs and 23 (5%) IP GPs were detected at 8.9 GHz, both with zero chance probability. Another 15 (4%) low-frequency IP GPs were detected within one spin period of high-frequency IP GPs, with a chance probability of 9%. This indicates that the emission processes at high and low radio frequencies are related, despite significant pulse profile shape differences. The 43 m GPs were also correlated with Fermi γ-ray photons to see if increased pair production in the magnetosphere is the mechanism responsible for GP emission. A total of 92,022 GPs and 393 γ-ray photons were used in this correlation analysis. No significant correlations were found between GPs and γ-ray photons. This indicates that increased pair production in the magnetosphere is likely not the dominant cause of GPs. Possible methods of GP production may be increased coherence of synchrotron emission or changes in beaming direction.

  1. A GIANT SAMPLE OF GIANT PULSES FROM THE CRAB PULSAR

    Energy Technology Data Exchange (ETDEWEB)

    Mickaliger, M. B.; McLaughlin, M. A.; Lorimer, D. R.; Palliyaguru, N. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Langston, G. I. [National Radio Astronomy Observatory, Green Bank, WV 24944 (United States); Bilous, A. V. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Kondratiev, V. I. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Lyutikov, M. [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907-2036 (United States); Ransom, S. M. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States)

    2012-11-20

    We observed the Crab pulsar with the 43 m telescope in Green Bank, WV over a timespan of 15 months. In total we obtained 100 hr of data at 1.2 GHz and seven hours at 330 MHz, resulting in a sample of about 95,000 giant pulses (GPs). This is the largest sample, to date, of GPs from the Crab pulsar taken with the same telescope and backend and analyzed as one data set. We calculated power-law fits to amplitude distributions for main pulse (MP) and interpulse (IP) GPs, resulting in indices in the range of 2.1-3.1 for MP GPs at 1.2 GHz and in the range of 2.5-3.0 and 2.4-3.1 for MP and IP GPs at 330 MHz. We also correlated the GPs at 1.2 GHz with GPs from the Robert C. Byrd Green Bank Telescope (GBT), which were obtained simultaneously at a higher frequency (8.9 GHz) over a span of 26 hr. In total, 7933 GPs from the 43 m telescope at 1.2 GHz and 39,900 GPs from the GBT were recorded during these contemporaneous observations. At 1.2 GHz, 236 (3%) MP GPs and 23 (5%) IP GPs were detected at 8.9 GHz, both with zero chance probability. Another 15 (4%) low-frequency IP GPs were detected within one spin period of high-frequency IP GPs, with a chance probability of 9%. This indicates that the emission processes at high and low radio frequencies are related, despite significant pulse profile shape differences. The 43 m GPs were also correlated with Fermi {gamma}-ray photons to see if increased pair production in the magnetosphere is the mechanism responsible for GP emission. A total of 92,022 GPs and 393 {gamma}-ray photons were used in this correlation analysis. No significant correlations were found between GPs and {gamma}-ray photons. This indicates that increased pair production in the magnetosphere is likely not the dominant cause of GPs. Possible methods of GP production may be increased coherence of synchrotron emission or changes in beaming direction.

  2. Inquiring into Red/Red Inquiring

    Directory of Open Access Journals (Sweden)

    Ken Gale

    2013-05-01

    Full Text Available This layered account of an inquiry into ‘red’ emerged out of a collective biography workshop. In the middle of the Wiltshire countryside, an international and interdisciplinary group of scholars gathered together to write and make other things and marks on paper that asked questions of, and into, the spaces between words, people, things and their environments. We did not set out to workshop or write into or paint ‘red’ but, rather, it was red that slipped in, uninvited, and painted and wrote us. Red arose as a blush or a stain seeping amongst us that became referenced obliquely by material objects, metaphors and fairytales. The stain spread, became noticeable through our weekend together and beyond it, creating another (bright red artery vein of connection to write with.

  3. Effects of certain burning treatments on veld condition in Giant's ...

    African Journals Online (AJOL)

    Effects of certain burning treatments on veld condition in Giant's Castle Game Reserve. ... Keywords: above-ground standing crop; basal cover; burning; composition change; giant's castle game reserve; natal ... AJOL African Journals Online.

  4. Interpretation of the spectrum of the Red Rectangle

    International Nuclear Information System (INIS)

    Greenstein, J.L.; Oke, J.B.

    1977-01-01

    The strong infrared source centered on HD 44179 has been observed with the multichannel spectrophotometer from 0.35μ to 1.1μ. The stellar spectrum is anomalous. If we fit a model atmosphere suitable for a late B giant it must have a circumstellar shell. If it is a low-gravity F bright giant its reported slit spectrum suggests unusual composition. The total luminosity is high, from the far infrared fluxes. The nebula, the Red Rectangle, has been observed without stellar contamination. Largely of the reflection type, it is unusual in being considerably redder than the star. The surface brightness is interpreted from the first-order and exact theory of scattering by grains in an optically thick nebula, with the star in front. The color is ascribed to the variation of the albedo with frequency. An unusual feature is a broad upward rise in brightness of the nebula, centered at 6600 A, requiring a four-fold increase in albedo over a region 1700 A wide (full width at half maximum). The albedo is so high that the most favorable geometry must be assumed; otherwise the red maximum might require fluorescence. If the high reflectivity in the red is a feature of the dust grains, they have composition quite different from other reflection nebulae, meteorites, or planets

  5. Hepatic Giant Cell Arteritis and Polymyalgia Rheumatica

    Directory of Open Access Journals (Sweden)

    Donald R Duerksen

    1994-01-01

    Full Text Available Polymyalgia rheumatica (PMR is a clinical syndrome of the elderly characterized by malaise, proximal muscle aching and stiffness, low grade fever, elevated erythrocyte sedimentation rare and the frequent association with temporal giant cell arteritis. The authors describe a case of PMR associated with hepatic giant cell arteritis. This lesion has been described in two other clinical reports. The distribution of the arteritis may be patchy; in this report, diagnosis was made with a wedge biopsy performed after an initial nonspecific percutaneous liver biopsy. The authors review the spectrum of liver involvement in PMR and giant cell arteritis. Hepatic abnormalities respond to systemic corticosteroids, and patients with hepatic arteritis have a good prognosis.

  6. Excitation of giant resonances through inelastic scattering

    International Nuclear Information System (INIS)

    Kailas, S.

    1981-01-01

    In the last few years, exciting developments have taken place in the study of giant resonances (GR). In addition to the already well known gjant dipole resonance (GDR), the presence of at least two more new GRs viz. giant quadrupole resonance (GQR) and giant monopole resonance (GMR) has been experimentally established. The systematics covering these GRs is found to be consistent with the theoretical expectation. Though the existence of higher multipoles has been predjcted by theory, so far only some of these have been found to be excited experimentally. Various probe particles - electrons, protons (polarized and unpolarized), light and heavy ions and pions - at different bombarding energies have been used to excite the GR region, primarily through the inelastic scattering process. Detailed experiments, looking at the decay modes of GR region, have also been performed. These studies have contributed significantly to a better understanding of the phenomenon of nuclear collective excitation. In this report, the current status of 'GR' research is reviewed. (author)

  7. Giant Epidermoid Cyst of the Thigh

    Directory of Open Access Journals (Sweden)

    NH Mohamed Haflah

    2011-11-01

    Full Text Available Epidermoid cyst is a common benign cutaneous swelling frequently encountered in surgical practice. It usually presents as a painless lump frequently occurring in hairbearing areas of the body particularly the scalp, scrotum, neck, shoulder and back. Giant epidermoid cysts commonly occur in hairy areas such as the scalp. We present here the case of a rare occurrence of a giant epidermoid cyst in the less hairy area of the right upper thigh mimicking a soft tissue sarcoma. Steps are highlighted for the management of this unusual cyst.

  8. Giant Spermatocele Mimicking Hydrocele: A Case Report

    Directory of Open Access Journals (Sweden)

    Hsin-Chih Yeh

    2007-07-01

    Full Text Available Spermatoceles are usually asymptomatic and often found incidentally during physical examination. We report a case of giant spermatocele that mimicked a hydrocele. A 55-year-old man suffered from right scrotal enlargement for several years. As the heavy sensation and scrotal soreness worsened in recent months, he came to our outpatient clinic for help. Hydrocele was suspected due to transilluminating appearance of the scrotal content. Surgical exploration was arranged and a giant spermatocele was found. Total excision of the spermatocele was performed and the patient recovered well. The specimen was sent for pathology and spermatocele with spermatozoa was noted.

  9. Neglected Giant Scalp Basal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Anne Kristine Larsen, MD

    2014-03-01

    Full Text Available Summary: Rarely, basal cell carcinoma grows to a giant size, invading the underlying deep tissue and complicating the treatment and reconstruction modalities. A giant basal cell carcinoma on the scalp is in some cases treated with a combination of surgery and radiation therapy, resulting in local control, a satisfactory long-term cosmetic and functional result. We present a case with a neglected basal cell scalp carcinoma, treated with wide excision and postoperative radiotherapy, reconstructed with a free latissimus dorsi flap. The cosmetic result is acceptable and there is no sign of recurrence 1 year postoperatively.

  10. Giant HII regions as distance indicators

    International Nuclear Information System (INIS)

    Melnick, Jorge; Terlevich, Robert; Moles, Mariano

    1987-01-01

    The correlations between the integrated Hβ luminosities, the velocity widths of the nebular lines and the metallicities of giant HII regions and HII galaxies are demonstrated to provide powerful distance indicators. They are calibrated on a homogeneous sample of giant HII regions with well determined distances and applied to distant HII galaxies to obtain a value of H 0 =95+-10 for the Hubble parameter, consistent with the value obtained by the Tully-Fisher technique. The effect of Malmquist bias and other systematic effects on the HII region method are discussed in detail. (Author)

  11. Isovector giant quadrupole resonance in 63Cu

    International Nuclear Information System (INIS)

    Wolynec, E.; Pastura, V.F.S.; Martins, M.N.

    1988-01-01

    The decay of the isovector E2 giant resonance in 63 Cu has been studied by measuring the (e,2n) cross section, in the incident electron energy range 22-45 MeV. The photodisintegration induced by bremsstrahlung was also measured. The electrodisintegration results have been analyzed using the distorted wave Born approximation E1 and E2 virtual photon spectra to obtain these multipole components in the corresponding (γ,2n) cross section. It is found that the isovector E2 giant resonance decays dominantly by two-neutron emission in 63 Cu. This decay channel exhausts 65 percent of the energy weighted E2 sum. (author0 [pt

  12. Probing giant magnetoresistance with THz spectroscopy

    DEFF Research Database (Denmark)

    Jin, Zuanming; Tkach, Alexander; Casper, Frederick

    2014-01-01

    We observe a giant magnetoresistance effect in CoFe/Cu-based multistack using THz time-domain spectroscopy. The magnetic field-dependent dc conductivity, electron scattering time, as well as spin-asymmetry parameter of the structure are successfully determined. © 2014 OSA.......We observe a giant magnetoresistance effect in CoFe/Cu-based multistack using THz time-domain spectroscopy. The magnetic field-dependent dc conductivity, electron scattering time, as well as spin-asymmetry parameter of the structure are successfully determined. © 2014 OSA....

  13. Atypical visual loss in giant cell arteritis

    DEFF Research Database (Denmark)

    Thystrup, Jan Deichmann; Knudsen, G M; Mogensen, A M

    1994-01-01

    Three patients with atypical ocular involvement due to histologically verified giant cell arteritis are reported. Prior to diagnosis, the first patient had periods of amaurosis fugax. He presented with normal vision. In spite of high-dose systemic corticosteroid therapy, he became blind in the te......Three patients with atypical ocular involvement due to histologically verified giant cell arteritis are reported. Prior to diagnosis, the first patient had periods of amaurosis fugax. He presented with normal vision. In spite of high-dose systemic corticosteroid therapy, he became blind...

  14. Giant Condyloma Acuminatum: A Surgical Riddle

    Directory of Open Access Journals (Sweden)

    Shukla

    2016-08-01

    Full Text Available Giant condyloma acuminatum (GCA commonly known as Buschke-Lowenstein tumor (BLT is a rare sexually transmitted disease, which is always preceded by condyloma accuminata and linked to human papillomavirus (HPV. Most commonly affected sites are male and female genitalia, anal and perianal regions. Giant condyloma acuminatum is well-known as slow growing but locally destructive with a high rate of recurrence and increased frequency of malignant transformation. Surgical management is considered to be the best among all the options.

  15. Observing giant panda habitat and forage abundance from space

    NARCIS (Netherlands)

    Wang, T.

    2009-01-01

    Giant pandas are obligate bamboo grazers. The bamboos favoured by giant
    pandas are typical forest understorey plants. Therefore, the availability and
    abundance of understorey bamboo is a key factor in determining the quantity
    and quality of giant panda food resources. However,

  16. Evidence for deformation effect on the giant monopole resonance

    International Nuclear Information System (INIS)

    Buenerd, M.; Lebrun, D.; Martin, P.; de Saintignon, P.; Perrin, C.

    1980-01-01

    The giant monopole resonance in the region of deformed nuclei has been investigated by inelastic scattering of 108.5 MeV 3 He at very small scattering angles. Evidence is reported for coupling between the giant monopole and giant quadrupole vibrations, based both on energy shift and transition strength

  17. Giant urinary bladder calculus: Case report | Otieno | East African ...

    African Journals Online (AJOL)

    A vertical calculus weighing more than 100 g is categorised as a giant urinary bladder stone. Giant urinary bladder stones are very rare and very few cases have been reported in English literature and only one case from Africa. This is a case report of a patient with a giant urinary bladder calculus presenting as a rectal ...

  18. Staged Closure of Giant Omphalocele using Synthetic Mesh

    OpenAIRE

    Parida, Lalit; Pal, Kamalesh; Al Buainain, Hussah; Elshafei, Hossam

    2014-01-01

    Giant omphalocele is difficult to manage and is associated with a poor outcome. A male newborn presented to our hospital with a giant omphalocele. We performed a staged closure of giant omphalocele using synthetic mesh to construct a silo and then mesh abdominoplasty in the neonatal period that led to a successful outcome within a reasonable period of hospital stay.

  19. Giant Panda habitat selection in the Foping Nature Reserve, China

    NARCIS (Netherlands)

    Liu, X.; Toxopeus, A.G.; Skidmore, A.K.; Shao, X.; Dang, D.; Wang, T.; Prins, H.H.T.

    2005-01-01

    Little is known about habitat selection of the giant panda (Ailuropoda melanoleuca), especially about the relationship between giant panda presence and bamboo and tree structures. We presented data on giant panda habitat use and selection in Foping Nature Reserve (NR), China. We used 1,066

  20. Ultrabass Sounds of the Giant Star xi Hya

    Science.gov (United States)

    2002-05-01

    times larger. The new observations demonstrate that xi Hya oscillates with several periods of around 3 hours. xi Hya is now approaching the end of its life - it is about to expand its outer envelope and to become a "red giant star" . It is quite different from stars like the Sun, which are only halfway through their active life. xi Hya is considerably more massive than any other star in which solar-like oscillations have so far been detected. This observational feat allows to study for the first time with seismic techniques the interior of such a highly evolved star. It paves the way for similar studies of different types of stars. A new chapter of stellar astrophysics is now opening as asteroseismology establishes itself as an ingenious method that is able to revolutionise our detailed understanding of stellar interiors and the overall evolution of stars . PR Photo 13a/02 : Oscillation frequencies in the Giant Star xi Hya PR Photo 13b/02 : Non-radial oscillations of xi Hya (computer graphics) PR Audio Clip 01/02 : Listen to the sound of xi Hya (RealMedia and MP3) The difficult art of asteroseismology Helioseismology (seismology of the Sun) is based on measurements of the changing radial velocity of the solar upper atmospheric layers (the "surface") by means of the well-known Doppler effect, as this surface moves up and down during acoustic oscillations. The corresponding amplitudes are very small, with velocities of up to 15 - 20 cm/sec, and the typical period is around 5 minutes. Therefore the phenomenon was first known as the "five-minute oscillations". Intensity measurements have also been tried, but the noise level is larger than for velocity data due to the presence of "granulation" (moving cells of hot gas) on the solar surface. In the case of larger and brighter stars like the giant stars, the corresponding amplitudes and periods increase. For instance, theoretical predictions for the giant star xi Hya have indicated that velocity amplitudes of about 7 m/sec and