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Sample records for tw hydrae young

  1. The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog

    CERN Document Server

    Kellogg, Kendra; Gagne, Jonathan; Faherty, Jacqueline

    2016-01-01

    In a recent search for unusually red L and T dwarfs, we identified 2MASS J11193254-1137466 as a likely young L7 dwarf and potential member of the TW Hydrae association. We present spectra that confirm the youth of this object. We also measure a radial velocity of 8.5 +/- 3.3 km/s that, together with the sky position, proper motion and photometric distance, results in a 92% probability of membership in the TW Hydrae association, with a calibrated field contamination probability of 0.0005% using the BANYAN II tool. Using the age of TW Hydrae and the luminosity of 2MASS J11193254-1137466, we estimate its mass to be 4.3--7.6 MJup. It is the lowest-mass and nearest isolated member of TW Hydrae at a kinematic distance of 28.9 +/- 3.6 pc, and the second-brightest isolated <10 MJup object discovered to date.

  2. Distance and Kinematics of the TW Hydrae Association from Parallaxes

    CERN Document Server

    Weinberger, Alycia J; Boss, Alan P

    2012-01-01

    From common proper motion and signatures of youth, researchers have identified about 30 members of a putative TW Hydrae Association. Only four of these had parallactic distances from Hipparcos. We have measured parallaxes and proper motions for 14 primary members. We combine these with literature values of radial velocities to show that the Galactic space motions of the stars, with the exception of TWA 9 and 22, are parallel and do not indicate convergence at a common formation point sometime in the last few million years. The space motions of TWA 9 and 22 do not agree with the others and indicate that they are not TWA members. The median parallax is 18 mas or 56 pc. We further analyze the stars' absolute magnitudes on pre-main sequence evolutionary tracks and find a range of ages with a median of 10.1 Myr and no correlation between age and Galactic location. The TWA stars may have formed from an extended and filamentary molecular cloud but are not necessarily precisely coeval.

  3. Revisiting TW Hydrae in light of new astrometric data

    Science.gov (United States)

    Teixeira, R.; Ducourant, C.; Galli, P. A. B.; Le Campion, J. F.; Zuckerman, B.; Krone-Martins, A. G. O.; Chauvin, G.; Song, I.

    2014-10-01

    Our efforts in the present work focused mainly on refining and improving the previous description and understanding of the stellar association TW Hydrae (TWA) including a very detailed membership analysis and its dynamical and evolutionary age.To achieve our objectives in a fully reliable way we take advantage of our own astrometric measurements (Ducourant et al. 2013) performed with NTT/EFOSC2 - ESO (La Silla - Chile) spread over three years (2007 - 2010) and of those published in the literature.A very detailed membership analysis based on the convergent point strategy as developed by our team (Galli et al. 2012, 2013) allowed us to define a consistent kinematic group containing 31 stars among the 44 proposed as TWA member in the literature. Assuming that our sample of stars may be contaminated by non-members and to get rid of the particular influence of each star we applied a Jacknife resampling technique generating 2000 random lists of 13 stars taken from our 16 stars and calculated for each the epoch of convergence when the radius is minimum. The mean of the epochs obtained and the dispersion about the mean give a dynamical age of 7.5± 0.7 Myr for the association that is in good agreement with the previous traceback age (De La Reza et al. 2006). We also estimated age for TWA moving group members from pre-main sequence evolutionary models (Siess et al. 2000) and find a mean age of 7.4± 1.2 Myr. These results show that the dynamical age of the association obtained via the traceback technique and the average age derived from theoretical evolutionary models are in good agreement.

  4. Volatile depletion in the TW Hydrae disk atmosphere

    CERN Document Server

    Du, Fujun; Hogerheijde, Michiel R

    2015-01-01

    An abundance decrease in carbon- and oxygen-bearing species relative to dust has been frequently found in planet-forming disks, which can be attributed to an overall reduction of gas mass. However, in the case of TW Hya, the only disk with gas mass measured directly with HD rotational lines, the inferred gas mass ($\\lesssim$0.005 solar mass) is significantly below the directly measured value ($\\gtrsim$0.05 solar mass). We show that this apparent conflict can be resolved if the elemental abundances of carbon and oxygen are reduced in the upper layers of the outer disk but are normal elsewhere (except for a possible enhancement of their abundances in the inner disk). The implication is that in the outer disk, the main reservoir of the volatiles (CO, water, ...) resides close to the midplane, locked up inside solid bodies that are too heavy to be transported back to the atmosphere by turbulence. An enhancement in the carbon and oxygen abundances in the inner disk can be caused by inward migration of these solid ...

  5. New members of the TW Hydrae Association and two accreting M-dwarfs in Scorpius-Centaurus

    CERN Document Server

    Murphy, Simon J; Bento, Joao

    2015-01-01

    We report the serendipitous discovery of several young mid-M stars found during a search for new members of the 30-40 Myr-old Octans Association. Only one of the stars may be considered a possible Octans(-Near) member. However, two stars have proper motions, kinematic distances, radial velocities, photometry and Li I 6708AA measurements consistent with membership in the 8-10 Myr-old TW Hydrae Association. Another may be an outlying member of TW Hydrae but has a velocity similar to that predicted by membership in Octans. We also identify two new lithium-rich members of the neighbouring Scorpius-Centaurus OB Association (Sco-Cen). Both exhibit large 12 and 22 micron excesses and strong, variable H-alpha emission which we attribute to accretion from circumstellar discs. Such stars are thought to be incredibly rare at the ~16 Myr median age of Sco-Cen and they join only one other confirmed M-type and three higher-mass accretors outside of Upper Scorpius. The serendipitous discovery of two accreting stars hosting ...

  6. Measuring turbulence in TW Hydrae with ALMA: methods and limitations

    Science.gov (United States)

    Teague, R.; Guilloteau, S.; Semenov, D.; Henning, Th.; Dutrey, A.; Piétu, V.; Birnstiel, T.; Chapillon, E.; Hollenbach, D.; Gorti, U.

    2016-07-01

    Aims: We aim to obtain a spatially resolved measurement of velocity dispersions in the disk of TW Hya. Methods: We obtained images with high spatial and spectral resolution of the CO J = 2-1, CN N = 2-1 and CS J = 5-4 emission with ALMA in Cycle 2. The radial distribution of the turbulent broadening was derived with two direct methods and one modelling approach. The first method requires a single transition and derives Tex directly from the line profile, yielding a vturb. The second method assumes that two different molecules are co-spatial, which allows using their relative line widths for calculating Tkin and vturb. Finally we fitted a parametric disk model in which the physical properties of the disk are described by power laws, to compare our direct methods with previous values. Results: The two direct methods were limited to the outer r > 40 au disk because of beam smear. The direct method found vturb to range from ≈130 m s-1 at 40 au, and to drop to ≈50 m s-1 in the outer disk, which is qualitatively recovered with the parametric model fitting. This corresponds to roughly 0.2-0.4 cs. CN was found to exhibit strong non-local thermal equilibrium effects outside r ≈ 140 au, so that vturb was limited to within this radius. The assumption that CN and CS are co-spatial is consistent with observed line widths only within r ≲ 100 au, within which vturb was found to drop from 100 m s-1 (≈0.4 cs) to zero at 100 au. The parametric model yielded a nearly constant 50 m s-1 for CS (0.2-0.4 cs). We demonstrate that absolute flux calibration is and will be the limiting factor in all studies of turbulence using a single molecule. Conclusions: The magnitude of the dispersion is comparable with or below that predicted by the magneto-rotational instability theory. A more precise comparison would require reaching an absolute calibration precision of about 3%, or finding a suitable combination of light and heavy molecules that are co-located in the disk. The reduced

  7. Keck Adaptive Optics Observations of TW Hydrae Association Members

    Energy Technology Data Exchange (ETDEWEB)

    Macintosh, B; Max, C; Zuckerman, B; Becklin, E E; Kaisler, D; Lowrance, P; Weinberger, A; Chirstou, J; Schneider, G; Acton, S

    2001-05-30

    Adaptive optics (AO) on 8-10 m telescopes is an enormously powerful tool for studying young nearby stars. It is especially useful for searching for companions. Using AO on the 10-m W.M. Keck II telescope we have measured the position of the brown dwarf companion to TWA5 and resolved the primary into an 0.055{double_prime} double. Over the next several years follow-up astrometry should permit an accurate determination of the masses of these young stars. We have also re-observed the candidate extrasolar planet TWAGB, but measurements of its motion relative to TWA6A are inconclusive. We are carrying out a search for new planetary or brown dwarf companions to TWA stars and, if current giant planet models are correct, are currently capable of detecting a 1 Jupiter-mass companion at {approx} 1.0{double_prime} and a 5 Jupiter-mass companion at {approx} 0.5{double_prime} around a typical TWA member.

  8. Peering into the Giant Planet Forming Region of the TW Hydrae Disk with the Gemini Planet Imager

    CERN Document Server

    Rapson, Valerie A; Millar-Blanchaer, Maxwell A; Dong, Ruobing

    2015-01-01

    We present Gemini Planet Imager (GPI) adaptive optics near-infrared images of the giant planet-forming regions of the protoplanetary disk orbiting the nearby (D = 54 pc), pre-main sequence (classical T Tauri) star TW Hydrae. The GPI images, which were obtained in coronagraphic/polarimetric mode, exploit starlight scattered off small dust grains to elucidate the surface density structure of the TW Hya disk from 80 AU to within 10 AU of the star at 1.5 AU resolution. The GPI polarized intensity images unambiguously con?rm the presence of a gap in the radial surface brightness distribution of the inner disk. The gap is centered near 23 AU, with a width of 5 AU and a depth of 50%. In the context of recent simulations of giant planet formation in gaseous, dusty disks orbiting pre-main sequence stars, these results indicate that at least one young planet with a mass 0.2 M_J could be present in the TW Hya disk at an orbital semi-major axis similar to that of Uranus. If this (proto)planet is actively accreting gas fr...

  9. A Chandra Observation of the TW Hydrae Association Brown Dwarf 2MASSW J1139511-315921

    CERN Document Server

    Castro, Philip J; Gagné, Marc

    2011-01-01

    We report on a sequence of Chandra X-ray Observatory observations of the TW Hydrae brown dwarf (BD) 2MASSW J1139511-315921 (2M1139). In the combined 31 ks ACIS-S exposure, 2M1139 is detected at the 3-sigma confidence level. We find an X-ray luminosity of L_X = 1.4^(+2.7)_(-1.0) x 10^26 ergs s^-1 or log(L_X/L_bol) = -4.8 +/- 0.3. This object is similar to another TW Hydrae BD member, CD-33 7795B (TWA 5B): both have H-alpha emission, both show no signatures of accretion, and both have comparable ages and spectral types. TWA 5B was previously detected in X-rays with a luminosity of L_X = 4 x 10^27 ergs s^-1 or log(L_X/L_bol) = -3.4, an order of magnitude more luminous in X-rays than 2M1139. We find that the discrepancy between the X-ray luminosity of 2M1139 and TWA 5B is consistent with the spread in X-ray luminosity in the Orion Nebula Cluster (ONC) for BDs of similar spectral types. Though rotation may play a role in the X-ray activity of ultracool dwarfs like 2M1139 and TWA 5B, the discrepancy cannot be expla...

  10. DISCOVERY OF A DISK GAP CANDIDATE AT 20 AU IN TW HYDRAE

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, E.; Kusakabe, N.; Kandori, R. [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan); Muto, T. [Division of Liberal Arts, Kogakuin University, 1-24-2, Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677 (Japan); Kataoka, A.; Kuzuhara, M. [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1, Oklahoma, Ookayama, Meguro-ko, Tokyo 152-8551 (Japan); Hashimoto, J.; Wisniewski, J. [Department of Physics and Astronomy, The University of Oklahoma, 440 W. Brooks Street, Norman, OK 73019 (United States); Tsukagoshi, T. [College of Science, Ibaraki University, 2-1-1, Bunkyo, Mito, Ibaraki 310-8512 (Japan); Kwon, J. [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kudo, T.; Currie, T. [Subaru Telescope, National Astronomical Observatory of Japan, 650, North A' ohoku Place, Hilo, HI 96720 (United States); Grady, C. A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Takami, M. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Janson, M. [Department of Astronomy, Stockholm University, AlbaNova University Center, Stockholm, SE-106 91 (Sweden); Henning, T.; Carson, J. C. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Sitko, M. L. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); Mayama, S. [The Center for the Promotion of Integrated Sciences, The Graduate University for Advance Studies, Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0115 (Japan); Thalmann, C., E-mail: eiji.akiyama@nao.ac.jp [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); and others

    2015-04-01

    We present a new Subaru/HiCIAO high-contrast H-band polarized intensity (PI) image of a nearby transitional disk associated with TW Hydrae. The scattered light from the disk was detected from 0.″ 2 to 1.″ 5 (11–81 AU) and the PI image shows a clear axisymmetric depression in PI at ∼0.″ 4 (∼20 AU) from the central star, similar to the ∼80 AU gap previously reported from Hubble Space Telescope images. The azimuthal PI profile also shows that the disk beyond 0.″ 2 is almost axisymmetric. We discuss two possible scenarios explaining the origin of the PI depression: (1) a gap structure may exist at ∼20 AU from the central star because of a shallow slope seen in the PI profile, and (2) grain growth may be occurring in the inner region of the disk. Multi-band observations at near-infrared and millimeter/submillimeter wavelengths play a complementary role in investigating dust opacity and may help reveal the origin of the gap more precisely.

  11. Discovery of a Disk Gap Candidate at 20 AU in TW Hydrae

    CERN Document Server

    Akiyama, E; Kusakabe, N; Kataoka, A; Hashimoto, J; Tuskagoshi, T; Kwon, J; Kudo, T; Kandori, R; Grady, C A; Takami, M; Janson, M; Kuzuhara, M; Henning, T; Sitko, M L; Mayama, J C Carson S; Currie, T; Thalmann, C; Wisniewski, J; Momose, M; Ohashi, N; Abe, L; Brandner, W; Brandt, T D; Egner, S; Feldt, M; Goto, M; Guyon, O; Hayano, Y; Hayashi, M; Hayashi, S; Hodapp, K W; Ishi, M; Iye, M; Knapp, G R; Matsuo, T; McElwain, M W; Miyama, S; Morino, J -I; Moro-Martin, A; Nishimura, T; Pyo, T -S; Serabyn, G; Suenaga, T; Suto, H; Suzuki, R; Takahashi, Y H; Takato, N; Terada, H; Tomono, D; Turner, E L; Watanabe, M; Yamada, T; Takami, H; Usuda, T; Tamura, M

    2015-01-01

    We present a new Subaru/HiCIAO high-contrast H-band polarized intensity (PI) image of a nearby transitional disk associated with TW Hydrae. The scattered light from the disk was detected from 0.2" to 1.5" (11 - 81 AU) and the PI image shows a clear axisymmetric depression in polarized intensity at ~ 0.4" (~ 20 AU) from the central star, similar to the ~ 80 AU gap previously reported from HST images. Azimuthal polarized intensity profile also shows the disk beyond 0.2" is almost axisymmetric. We discuss two possible scenarios explaining the origin of the polarized intensity depression: 1) a gap structure may exist at ~ 20 AU from the central star because of shallow slope seen in the polarized intensity profile, and 2) grain growth may be occurring in the inner region of the disk. Multi-band observations at NIR and millimeter/sub-millimeter wavelengths play a complementary role in investigating dust opacity and may help reveal the origin of the gap more precisely.

  12. Heatflow in Young Oceanic Crust. Is Earth's Heat Flux 44 TW or 31 TW?

    Science.gov (United States)

    Gosnold, W. D.

    2008-05-01

    We address the question of heat flow in young oceanic crust using a 2-D finite difference heat flow model of sea floor spreading. The model parameters include thermal conductivity variation with temperature, a fixed T-z profile at the ridge that follows the mantle liquidus, constant spreading rate, and constant heat flow into the base of the lithosphere. The output of the model is a 2-D temperature-depth grid that provides a comparison with various analytical models of oceanic heat flow. We tested the reliability of the computations using different half-spreading rates and different node spacings and verified that the models yield equivalent results at equivalent times and depths. To address the question of global heat flux with respect to heat flow at oceanic spreading centers, we summed heat flux on the oceanic ridge system assuming a length of 65000 km and a half-spreading rate of 2.5 cm/y. Our results show that the GDH1, HSC, and PSM models overestimate heat flow close to the ridge, but the differences are less than 5 percent beyond 2 ma. Our model converges with GDH1 at a young age of 4.32 my and actually shows slightly lower heat flow than HSC and PSM models for ages greater than 5 ma. Total heat flux for GDH1 between 80ky and 2.32 my is 6.24 TW and our model yields 5.56 TW. Assuming agreement with heat flux over the rest of the globe, our model is only 0.68 TW different from 44TW. However, our result for heat flux in a 2 km wide section over the global ridge crest is 0.161 TW while the analytical models predict infinite heat flow.

  13. Hydra

    DEFF Research Database (Denmark)

    Peder Pedersen, Claus

    2009-01-01

    Præsentation af forskningsprojekt relateret til den græske ø Hydra med fokus på konception og arkitekturtegning.......Præsentation af forskningsprojekt relateret til den græske ø Hydra med fokus på konception og arkitekturtegning....

  14. Hydra

    DEFF Research Database (Denmark)

    Peder Pedersen, Claus; Dinesen, Cort Ross

    2009-01-01

    Beskrivelse af kontekst og baggrund for et forskningsprojekt gennemført på den græske ø Hydra i perioden 2004-2008......Beskrivelse af kontekst og baggrund for et forskningsprojekt gennemført på den græske ø Hydra i perioden 2004-2008...

  15. Physical parameters of late M-type members of Chamaleon I and TW Hydrae Association: Dust settling, age dispersion and activity

    CERN Document Server

    Bayo, A; Allard, F; Henning, T; Comeron, F; Morales-Calderon, M; Rajpurohit, A S; Ramırez, K Pena; Beamın, J C

    2016-01-01

    Although mid-to-late type M dwarfs are the most common stars in our stellar neighborhood, our knowledge of these objects is still limited. Open questions include the evolution of their angular momentum, internal structures, dust settling in their atmospheres, age dispersion within populations. In addition, at young ages, late-type Ms have masses below the hydrogen burning limit and therefore are key objects in the debate on the brown dwarf mechanism of formation. In this work we determine and study in detail the physical parameters of two samples of young, late M-type sources belonging to either the Chamaeleon I Dark Cloud or the TW Hydrae Association and compare them with the results obtained in the literature for other young clusters and also for older, field, dwarfs. We used multi-wavelength photometry to construct and analyze SEDs to determine general properties of the photosphere and disk presence. We also used low resolution optical and near-infrared spectroscopy to study activity, accretion, gravity an...

  16. Evidence for Accretion High-Resolution X-ray Spectroscopy of the Classical T Tauri Star TW Hydrae

    CERN Document Server

    Kästner, J H; Schulz, N S; Canizares, C R; Weintraub, D A; Kastner, Joel H.; Huenemoerder, David P.; Schulz, Norbert S.; Canizares, Claude R.; Weintraub, David A.

    2002-01-01

    We present high resolution X-ray spectra of the X-ray bright classical T Tauri star, TW Hydrae, covering the wavelength range of 1.5-25 AA. The differential emission measure derived from fluxes of temperature-sensitive emission lines shows a plasma with a sharply peaked temperature distribution, peaking at log T = 6.5. Abundance anomalies are apparent, with iron very deficient relative to oxygen, while neon is enhanced relative to oxygen. Density-sensitive line ratios of Ne IX and O VII indicate densities near log n_e = 13. A flare with rapid (~1 ks) rise time was detected during our 48 ksec observation; however, based on analysis of the emission-line spectrum during quiescent and flaring states, the derived plasma parameters do not appear strongly time-dependent. The inferred plasma temperature distribution and densities are consistent with a model in which the bulk of the X-ray emission from TW Hya is generated via mass accretion from its circumstellar disk. Assuming accretion powers the X-ray emission, our...

  17. Detection of H2D+: Measuring the Midplane Degree of Ionization in the Disks of DM Tauri and TW Hydrae

    NARCIS (Netherlands)

    Ceccarelli, C.; Dominik, C.; Lefloch, B.; Caselli, P.; Caux, E.

    2004-01-01

    We report the first detection of the ground transition of the ortho-H2D+ molecule toward one disk source, DM Tau, a tentative detection toward TW Hya, and an upper limit toward LkCa 15. The three observed sources possess young gas-rich disks with large CO depletion factors. We argue that the observe

  18. Uncertainties in water chemistry in disks: An application to TW Hydrae

    Science.gov (United States)

    Kamp, I.; Thi, W.-F.; Meeus, G.; Woitke, P.; Pinte, C.; Meijerink, R.; Spaans, M.; Pascucci, I.; Aresu, G.; Dent, W. R. F.

    2013-11-01

    Context. This paper discusses the sensitivity of water lines to chemical processes and radiative transfer for the protoplanetary disk around TW Hya. The study focuses on the Herschel spectral range in the context of new line detections with the PACS instrument from the Gas in Protoplanetary Systems project (GASPS). Aims: The paper presents an overview of the chemistry in the main water reservoirs in the disk around TW Hya. It discusses the limitations in the interpretation of observed water line fluxes. Methods: We use a previously published thermo-chemical Protoplanetary Disk Model (ProDiMo) of the disk around TW Hya and study a range of chemical modeling uncertainties: metallicity, C/O ratio, and reaction pathways and rates leading to the formation of water. We provide results for the simplified assumption of Tgas = Tdust to quantify uncertainties arising for the complex heating/cooling processes of the gas and elaborate on limitations due to water line radiative transfer. Results: We report new line detections of p-H2O (322-211) at 89.99 μm and CO J = 18-17 at 144.78 μm for the disk around TW Hya. Disk modeling shows that the far-IR fine structure lines ([O i], [C ii]) and molecular submm lines are very robust to uncertainties in the chemistry, while the water line fluxes can change by factors of a few. The water lines are optically thick, sub-thermally excited and can couple to the background continuum radiation field. The low-excitation water lines are also sensitive to uncertainties in the collision rates, e.g. with neutral hydrogen. The gas temperature plays an important role for the [O i] fine structure line fluxes, the water line fluxes originating from the inner disk as well as the high excitation CO, CH+ and OH lines. Conclusions: Due to their sensitivity on chemical input data and radiative transfer, water lines have to be used cautiously for understanding details of the disk structure. Water lines covering a wide range of excitation energies provide

  19. Discovery of seven T Tauri stars and a brown dwarf candidate in the nearby TW Hydrae Association

    CERN Document Server

    Webb, R A; Platais, I; Patience, J; White, R J; Schwartz, M J; McCarthy, C

    1999-01-01

    We report the discovery of five T Tauri star systems, two of which are resolved binaries, in the vicinity of the nearest known region of recent star formation, the TW Hydrae Association. The newly discovered systems display the same signatures of youth (namely high X-ray flux, large Li abundance and strong chromospheric activity) and the same proper motion as the original five members. These similarities firmly establish the group as a bona fide T Tauri association, unique in its proximity to Earth and its complete isolation from any known molecular clouds. At an age of ~10 Myr and a distance of ~50 pc, the association members are excellent candidates for future studies of circumstellar disk dissipation and the formation of brown dwarfs and planets. Indeed, as an example, our speckle imaging revealed a faint, very likely companion 2" north of CoD-33 7795 (TWA 5). Its color and brightness suggest a spectral type ~M8.5 which, at an age of ~10^7 years, implies a mass ~20 M(Jupiter).

  20. Physical parameters of late M-type members of Chamaeleon I and TW Hydrae Association: dust settling, age dispersion and activity

    Science.gov (United States)

    Bayo, A.; Barrado, D.; Allard, F.; Henning, T.; Comerón, F.; Morales-Calderón, M.; Rajpurohit, A. S.; Peña Ramírez, K.; Beamín, J. C.

    2017-02-01

    Although mid-to-late type M dwarfs are the most common stars in our stellar neighbourhood, our knowledge of these objects is still limited. Open questions include the evolution of their angular momentum, internal structures, dust settling in their atmospheres and age dispersion within populations. In addition, at young ages, late-type Ms have masses below the hydrogen burning limit and therefore are key objects in the debate on the brown dwarf mechanism of formation. In this work, we determine and study in detail the physical parameters of two samples of young, late M-type sources belonging to either the Chamaeleon I dark cloud or the TW Hydrae Association and compare them with the results obtained in the literature for other young clusters and also for older, field, dwarfs. We used multiwavelength photometry to construct and analyse SEDs to determine general properties of the photosphere and disc presence. We also used low-resolution optical and near-infrared spectroscopy to study activity, accretion, gravity and effective temperature sensitive indicators. We propose a Virtual Observatory-based spectral index that is both temperature and age sensitive. We derived physical parameters using independent techniques confirming the already common feature/problem of the age/luminosity spread. In particular, we highlight two brown dwarfs showing very similar temperatures but clearly different surface gravity (explained invoking extreme early accretion). We also show how, despite large improvement in the dust treatment in theoretical models, there is still room for further progress in the simultaneous reproduction of the optical and near-infrared features of these cold young objects.

  1. Three radial gaps in the disk of TW Hydrae imaged with SPHERE

    CERN Document Server

    van Boekel, Roy; Menu, Jonathan; de Boer, Jos; Langlois, Maud; Müller, André; Avenhaus, Henning; Boccaletti, Anthony; Schmid, Hans Martin; Thalmann, Christian; Benisty, Myriam; Dominik, Carsten; Ginski, Christian; Girard, Julien H; Gisler, Daniel; Gomes, Aiara Lobo; Menard, Francois; Min, Michiel; Pavlov, Alexey; Pohl, Adriana; Quanz, Sascha P; Rabou, Patrick; Roelfsema, Ronald; Sauvage, Jean-François; Teague, Rich; Wildi, Francois; Zurlo, Alice

    2016-01-01

    We present scattered light images of the TW Hya disk performed with SPHERE in PDI mode at 0.63, 0.79, 1.24 and 1.62 micron. We also present H2/H3-band ADI observations. Three distinct radial depressions in the polarized intensity distribution are seen, around 85, 21, and 6~au. The overall intensity distribution has a high degree of azimuthal symmetry; the disk is somewhat brighter than average towards the South and darker towards the North-West. The ADI observations yielded no signifiant detection of point sources in the disk. Our observations have a linear spatial resolution of 1 to 2au, similar to that of recent ALMA dust continuum observations. The sub-micron sized dust grains that dominate the light scattering in the disk surface are strongly coupled to the gas. We created a radiative transfer disk model with self-consistent temperature and vertical structure iteration and including grain size-dependent dust settling. This method may provide independent constraints on the gas distribution at higher spatia...

  2. Magnetically Controlled Accretion on the Classical T Tauri Stars GQ Lupi and TW Hydrae

    CERN Document Server

    Johns-Krull, C M; Valenti, J A; Jeffers, S V; Piskunov, N E; Kuchukhov, O; Makaganiuk, V; Stempels, H C; Snik, F; Keller, C; Rodenhuis, M

    2013-01-01

    We present high spectral resolution ($R\\approx108,000$) Stokes $V$ polarimetry of the Classical T Tauri stars (CTTSs) GQ Lup and TW Hya obtained with the polarimetric upgrade to the HARPS spectrometer on the ESO 3.6 m telescope. We present data on both photospheric lines and emission lines, concentrating our discussion on the polarization properties of the \\ion{He}{1} emission lines at 5876 \\AA\\ and 6678 \\AA. The \\ion{He}{1} lines in these CTTSs contain both narrow emission cores, believed to come from near the accretion shock region on these stars, and broad emission components which may come from either a wind or the large scale magnetospheric accretion flow. We detect strong polarization in the narrow component of the two \\ion{He}{1} emission lines in both stars. We observe a maximum implied field strength of $6.05 \\pm 0.24$ kG in the 5876 \\AA\\ line of GQ Lup, making it the star with the highest field strength measured in this line for a CTTS. We find field strengths in the two \\ion{He}{1} lines that are c...

  3. MBM12: A Close, Younger Version of the TW Hydrae Association

    Science.gov (United States)

    Wolk, S. J.; Hearty, T.; Jayawardhana, R.

    2000-01-01

    MBM 12 is a dark cloud located about 65 pc from the sun. During the late 1980's and early 1990's, five Classical T Tauri stars were discovered associated with the cloud. The co-existence of the cloud and several stars with disks implies a very young association, very close to the earth. Such an association would be in a league with TWA and Eta Cham. However, at an estimated age of about 1 Myrs. Brown dwarfs/Jupiters would be brighter and disk should be more numerous. Deep ROSAT images and follow up spectroscopic observations raised the cluster membership to 8. We have expanded on this study with deep groundbased imaging, followup spectroscopy and infrared data. We discuss our current data base of U through I observations (complete to V=20) J through K observations (complete to K=14) and spectra of most stars above V magnitude 15. We will present a mass function for the about 40 stars now identified with the association and discuss disk, binary and brown dwarf candidates.

  4. The state of protoplanetary material 10 Myr after stellar formation: circumstellar disks in the TW Hydrae association

    CERN Document Server

    Uchida, K I; Hartmann, L; Kemper, F; Forrest, W J; Watson, D M; D'Alessio, P; Chen, C H; Furlan, E; Sargent, B; Brandl, B R; Herter, T L; Morris, P; Myers, P C; Najita, J R; Sloan, G C; Barry, J; Green, J; Keller, L D; Hall, P

    2004-01-01

    We have used the Spitzer Infrared Spectrograph to observe seven members of the TW Hya association, the nearest stellar association whose age ($\\sim$ 10 Myr) is similar to the timescales thought to apply to planet formation and disk dissipation. Only two of the seven targets display infrared excess emission, indicating that substantial amounts of dust still exist closer to the stars than is characteristic of debris disks; however, in both objects we confirm an abrupt short-wavelength edge to the excess, as is seen in disks with cleared-out central regions. The mid-infrared excesses in the spectra of Hen 3-600 and TW Hya include crystalline silicate emission features, indicating that the grains have undergone significant thermal processing. We offer a detailed comparison between the spectra of TW Hya and Hen 3-600, and a model that corroborates the spectral shape and our previous understanding of the radial structure of these protoplanetary disks.

  5. A TARGETED SEARCH FOR PECULIARLY RED L AND T DWARFS IN SDSS, 2MASS, AND WISE: DISCOVERY OF A POSSIBLE L7 MEMBER OF THE TW HYDRAE ASSOCIATION

    Energy Technology Data Exchange (ETDEWEB)

    Kellogg, Kendra; Metchev, Stanimir [Western University, Centre for Planetary and Space Exploration, 1151 Richmond St, London, ON N6A 3K7 (Canada); Geißler, Kerstin; Hicks, Shannon [Stony Brook University, Stony Brook, NY 11790 (United States); Kirkpatrick, J. Davy [Infrared Processing and Analysis Center, Mail Code 100-22, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Kurtev, Radostin, E-mail: kkellogg@uwo.ca, E-mail: smetchev@uwo.ca [Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Ave. Gran Bretaña 1111, Playa Ancha, Casilla 53, Valparaíso (Chile)

    2015-12-15

    We present the first results from a targeted search for brown dwarfs with unusual red colors indicative of peculiar atmospheric characteristics. These include objects with low surface gravities or with unusual dust content or cloud properties. From a positional cross-match of SDSS, 2MASS, and WISE, we have identified 40 candidate peculiar early-L to early-T dwarfs that are either new objects or have not been identified as peculiar through prior spectroscopy. Using low-resolution spectra, we confirm that 10 of the candidates are either peculiar or potential L/T binaries. With a J − K{sub s} color of 2.62 ± 0.15 mag, one of the new objects—the L7 dwarf 2MASS J11193254–1137466—is among the reddest field dwarfs currently known. Its proper motion and photometric parallax indicate that it is a possible member of the TW Hydrae moving group. If confirmed, it would be the lowest-mass (5–6 M{sub Jup}) free-floating member. We also report a new T dwarf, 2MASS J22153705+2110554, that was previously overlooked in the SDSS footprint. These new discoveries demonstrate that despite the considerable scrutiny already devoted to the SDSS and 2MASS surveys, our exploration of these data sets is not yet complete.

  6. X-ray Emission from Young Stars in the TW Hya Association

    CERN Document Server

    Brown, Alexander; Ayres, Thomas R; France, Kevin; Brown, Joanna M

    2014-01-01

    The 9 Myr old TW Hya Association (TWA) is the nearest group (typical distances of $\\sim$50 pc) of pre-main-sequence (PMS) stars with ages less than 10 Myr and contains stars with both actively accreting disks and debris disks. We have studied the coronal X-ray emission from a group of low mass TWA common proper motion binaries using the {\\it{Chandra}} and {\\it{Swift}} satellites. Our aim is to understand better their coronal properties and how high energy photons affect the conditions around young stars and their role in photo-exciting atoms, molecules and dust grains in circumstellar disks and lower density circumstellar gas. Once planet formation is underway, this emission influences protoplanetary evolution and the atmospheric conditions of the newly-formed planets. The X-ray properties for 7 individual stars (TWA 13A, TWA 13B, TWA 9A, TWA 9B, TWA 8A, TWA 8B, and TWA 7) and 2 combined binary systems (TWA 3AB and TWA 2AB) have been measured. All the stars with sufficient signal require two-component fits to...

  7. High spatial resolution mid-infrared observations of the low-mass young star TW Hya

    CERN Document Server

    Ratzka, T; Henning, T; Bouwman, J; Dullemond, C P; Jaffe, W

    2007-01-01

    We want to improve knowledge of the structure of the inner few AU of the circumstellar disk around the nearby T Tauri star TW Hya. Earlier studies have suggested the existence of a large inner hole, possibly caused by interactions with a growing protoplanet. We used interferometric observations in the N-band obtained with the MIDI instrument on the Very Large Telescope Interferometer, together with 10 micron spectra recorded by the infrared satellite Spitzer. The fact that we were able to determine N-band correlated fluxes and visibilities for this comparatively faint source shows that MIR interferometry can be applied to a large number of low-mass young stellar objects. The MIR spectra obtained with Spitzer reveal emission lines from HI (6-5), HI (7-6), and [Ne II] and show that over 90% of the dust we see in this wavelength regime is amorphous. According to the correlated flux measured with MIDI, most of the crystalline material is in the inner, unresolved part of the disk, about 1 AU in radius. The visibil...

  8. X-ray Emission from Young Stars in the TW Hya Association

    Science.gov (United States)

    Brown, Alexander; Herczeg, Gregory J.; Ayres, Thomas R.; France, Kevin; Brown, Joanna M.

    2015-01-01

    The 9 Myr old TW Hya Association (TWA) is the nearest group (typical distances of ˜50 pc) of pre-main-sequence (PMS) stars with ages less than 10 Myr and contains stars with both actively accreting disks and debris disks. We have studied the coronal X-ray emission from a group of low mass TWA common proper motion binaries using the Chandra and Swift satellites. Our aim is to understand better their coronal properties and how high energy photons affect the conditions around young stars and their role in photo-exciting atoms, molecules and dust grains in circumstellar disks and lower density circumstellar gas. Once planet formation is underway, this emission influences protoplanetary evolution and the atmospheric conditions of the newly-formed planets. The X-ray properties for 7 individual stars (TWA 13A, TWA 13B, TWA 9A, TWA 9B, TWA 8A, TWA 8B, and TWA 7) and 2 combined binary systems (TWA 3AB and TWA 2AB) have been measured. All the stars with sufficient signal require two-component fits to their CCD-resolution X-ray spectra, typically with a dominant hot (~2 kev (25 MK)) component and a cooler component at ~0.4 keV (4 MK). The brighter sources all show significant X-ray variability (at a level of 50-100% of quiescence) over the course of 5-15 ksec observations due to flares. We present the X-ray properties for each of the stars and find that the coronal emission is in the super-saturated rotational domain.

  9. First detection of gas-phase ammonia in a planet-forming disk. NH3, N2H+, and H2O in the disk around TW Hydrae

    Science.gov (United States)

    Salinas, Vachail N.; Hogerheijde, Michiel R.; Bergin, Edwin A.; Cleeves, L. Ilsedore; Brinch, Christian; Blake, Geoffrey A.; Lis, Dariusz C.; Melnick, Gary J.; Panić, Olja; Pearson, John C.; Kristensen, Lars; Yıldız, Umut A.; van Dishoeck, Ewine F.

    2016-06-01

    Context. Nitrogen chemistry in protoplanetary disks and the freeze-out on dust particles is key for understanding the formation of nitrogen-bearing species in early solar system analogs. In dense cores, 10% to 20% of the nitrogen reservoir is locked up in ices such as NH3, NH4+ and OCN-. So far, ammonia has not been detected beyond the snowline in protoplanetary disks. Aims: We aim to find gas-phase ammonia in a protoplanetary disk and characterize its abundance with respect to water vapor. Methods: Using HIFI on the Herschel Space Observatory, we detected for the first time the ground-state rotational emission of ortho-NH3 in a protoplanetary disk around TW Hya. We used detailed models of the disk's physical structure and the chemistry of ammonia and water to infer the amounts of gas-phase molecules of these species. We explored two radial distributions (extended across the disk and confined to distributions (near the midplane and at intermediate heights above the midplane, where water is expected to photodesorb off icy grains) to describe the (unknown) location of the molecules. These distributions capture the effects of radial drift and vertical settling of ice-covered grains. Results: The NH310-00 line is detected simultaneously with H2O 110-101 at an antenna temperature of 15.3 mK in the Herschel beam; the same spectrum also contains the N2H+ 6-5 line with a strength of 18.1 mK. We use physical-chemical models to reproduce the fluxes and assume that water and ammonia are cospatial. We infer ammonia gas-phase masses of 0.7-11.0 × 1021 g, depending on the adopted spatial distribution, in line with previous literature estimates. For water, we infer gas-phase masses of 0.2-16.0 × 1022 g, improving upon earlier literature estimates This corresponds to NH3/H2O abundance ratios of 7%-84%, assuming that water and ammonia are co-located. The inferred N2H+ gas mass of 4.9 × 1021 g agrees well with earlier literature estimates that were based on lower excitation

  10. Magnetic activity in the young solar analog LQ Hydrae. I. Active longitudes and cycles

    Science.gov (United States)

    Berdyugina, S. V.; Pelt, J.; Tuominen, I.

    2002-11-01

    We present the first evidence that a single active dwarf of solar type can show a long-lived, nonaxisymmetric spot distribution - active longitudes on opposite hemispheres, similar to evolved, rapidly rotating RS CVn-type binary stars. We analyse new as well as published photometric observations of the young active dwarf LQ Hya, spanning almost 20 years. We find that activity of the star has three activity cycles: a 5.2-yr ``flip-flop'' cycle, a 7.7-yr period in the amplitude modulation of the brightness and an approximately 15-yr period in variations of the mean brightness. The two shorter cycles are related to the alternating active longitudes and are similar to cycles observed in RS CVn-type stars. The 15-yr cycle reflects periodic changes of the mean spottedness of the star and resembles the solar 11-year cycle. The spot rotation period (about 1.6 days) changes during the 15-yr cycle, indicating the presence of small differential rotation. The lengths of the three cycles are related as 3:2:1, with the repetition of the spot configuration after 15 years. We discuss the possibility that the observed spot cycles represent two different magnetic dynamo modes operating in LQ Hya: an axisymmetric mode, as in the Sun, and a nonaxisymmetric higher order mode with two cycles in spot patterns. Our results suggest that young stars exhibit their cycles in spot distribution, as seen in LQ Hya. This is in contrast to the conclusion based on the analysis of Ca Ii H&K emission from plages. The results suggest also that the Vaughan-Preston gap represents a transition from a multiple-mode dynamo to a single-mode dynamo. Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/394/505

  11. Target irradiation experiments. [Hydra accelerator

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    Target irradiation experiments have been carried out on the Hydra accelerator, operating at powers between 0.15 and 0.3 TW. As listed in Table I, four types of spherical shell targets have been studied: 3 mm diameter, 200 ..mu..m and 50 ..mu..m wall thickness Au targets; 3 mm diameter, 300 ..mu..m wall thickness plastic targets; and 0.85 mm diameter, 10 ..mu..m wall thickness Ni targets. When compared to a practical range for 700 keV electrons, the ratio of shell thickness to electron range varied between 0.03 for the Ni targets to 1.5 for the thick walled Au targets. Multiple exposure optical holography was utilized to determine ablator velocity, and a one-dimensional hydrodynamical materials code CHARTD was utilized to model target response and infer beam deposition. Energy deposition varied from 1 TW/gm for thick Au targets up to 8 TW/gm for thin Ni targets, and pusher velocities ranged between 0.5 and 3.5 cm/..mu..sec. Neutron production from D/sub 2/ and DT filled Ni exploding pusher targets was measured using Ag and Li activation counters and gated scintillator photomultiplier time of flight detectors.

  12. TW Hya Association Membership and New WISE-detected Circumstellar Disks

    CERN Document Server

    Schneider, Adam; Song, Inseok

    2012-01-01

    We assess the current membership of the nearby, young TW Hydrae Association and examine newly proposed members with the Wide-field Infrared Survey Explorer (WISE) to search for infrared excess indicative of circumstellar disks. Newly proposed members TWA 30A, TWA 30B, TWA 31, and TWA 32 all show excess emission at 12 and 22 \\mum providing clear evidence for substantial dusty circumstellar disks around these low-mass, ~8 Myr old stars that were previously shown to likely be accreting from circumstellar material. TWA 30B shows large amounts of self-extinction, likely due to an edge-on disk geometry. We also confirm previously reported circumstellar disks with WISE, and determine a 22 \\mum excess fraction of 42+/- 9% based on our results.

  13. MBM12 A Younger Version of the TW Hydrae Association?

    CERN Document Server

    Wolk, S J; Jayawardhana, R; Hearty, T J; Wolk, Scott J.; Cover, Rebecca T.; Jayawardhana, Ray; Hearty, Thomas J.

    2000-01-01

    We present optical and infrared photometry of stars near the MBM 12 dark cloud. The optical data indicate that there are about 40 candidate pre-main sequence stars in the same area currently occupied by eight bona-fide PMS stars. Analysis of 2MASS data suggests that 60% of PMS candidates have been detected. Some of these show evidence of optically thick disks. Our study of the 2MASS data also reveals a large enhancement of sources within the MBM 12 cloud, indicating that it is still actively forming stars.

  14. A formation scenario of young stellar groups in the region of the Scorpio Centaurus OB association

    CERN Document Server

    Ortega, V G; De la Reza, R; Bazzanella, B

    2009-01-01

    The main objective of this work is to investigate the role played by Lower Centaurus Crux (LCC) and Upper Centaurus Lupus (UCL), both subcomponents of the Scorpio Centaurus OB association (Sco-Cen), in the formation of the groups beta Pictoris, TW Hydrae and the eta Chamaeleontis cluster. The dynamical evolution of all the stellar groups involved and of the bubbles and shells blown by LCC and UCL are calculated and followed from the past to the present. This leads to a formation scenario in which (1) the groups beta Pictoris, TW Hydrae were formed in the wake of the shells created by LCC and UCL, (2) the young cluster eta Chamaeleontis was born as a consequence of the collision of the shells of LCC and UCL, and (3) the formation of Upper Scorpius (US), the other main subcomponent of the Sco-Cen association, may have been started by the same process that created eta Chamaeleontis.

  15. Sommerskole 2004 - Hydra

    DEFF Research Database (Denmark)

    2004-01-01

    Montagen af/som nye erfaringsrum: intensiteter gennem disjunktioner. Arbejdsprocessen var struktureret gennem en række fortløbende spørgsmål, der blev formuleret successivt i perioden. Hydra kan ses som en kompleks topologisk konfiguration: hvis man betragter dens morfologi som en plastisk membra...... - en latex hvorigennem de topologiske kræfter tegner konturer - vil særlige strukturer danne ar i væv. Hydra kan ses som 2 komplekse topologiske og morfologiske plastiske membraner, der overførte eller snarere relaterede sine "mulige ny ar, rifter, knuder og forvridninger" i en symbiose...

  16. The dynamic genome of Hydra

    Science.gov (United States)

    Chapman, Jarrod A.; Kirkness, Ewen F.; Simakov, Oleg; Hampson, Steven E.; Mitros, Therese; Weinmaier, Therese; Rattei, Thomas; Balasubramanian, Prakash G.; Borman, Jon; Busam, Dana; Disbennett, Kathryn; Pfannkoch, Cynthia; Sumin, Nadezhda; Sutton, Granger G.; Viswanathan, Lakshmi Devi; Walenz, Brian; Goodstein, David M.; Hellsten, Uffe; Kawashima, Takeshi; Prochnik, Simon E.; Putnam, Nicholas H.; Shu, Shengquiang; Blumberg, Bruce; Dana, Catherine E.; Gee, Lydia; Kibler, Dennis F.; Law, Lee; Lindgens, Dirk; Martinez, Daniel E.; Peng, Jisong; Wigge, Philip A.; Bertulat, Bianca; Guder, Corina; Nakamura, Yukio; Ozbek, Suat; Watanabe, Hiroshi; Khalturin, Konstantin; Hemmrich, Georg; Franke, André; Augustin, René; Fraune, Sebastian; Hayakawa, Eisuke; Hayakawa, Shiho; Hirose, Mamiko; Hwang, Jung Shan; Ikeo, Kazuho; Nishimiya-Fujisawa, Chiemi; Ogura, Atshushi; Takahashi, Toshio; Steinmetz, Patrick R. H.; Zhang, Xiaoming; Aufschnaiter, Roland; Eder, Marie-Kristin; Gorny, Anne-Kathrin; Salvenmoser, Willi; Heimberg, Alysha M.; Wheeler, Benjamin M.; Peterson, Kevin J.; Böttger, Angelika; Tischler, Patrick; Wolf, Alexander; Gojobori, Takashi; Remington, Karin A.; Strausberg, Robert L.; Venter, J. Craig; Technau, Ulrich; Hobmayer, Bert; Bosch, Thomas C. G.; Holstein, Thomas W.; Fujisawa, Toshitaka; Bode, Hans R.; David, Charles N.; Rokhsar, Daniel S.; Steele, Robert E.

    2015-01-01

    The freshwater cnidarian Hydra was first described in 17021 and has been the object of study for 300 years. Experimental studies of Hydra between 1736 and 1744 culminated in the discovery of asexual reproduction of an animal by budding, the first description of regeneration in an animal, and successful transplantation of tissue between animals2. Today, Hydra is an important model for studies of axial patterning3, stem cell biology4 and regeneration5. Here we report the genome of Hydra magnipapillata and compare it to the genomes of the anthozoan Nematostella vectensis6 and other animals. The Hydra genome has been shaped by bursts of transposable element expansion, horizontal gene transfer, trans-splicing, and simplification of gene structure and gene content that parallel simplification of the Hydra life cycle. We also report the sequence of the genome of a novel bacterium stably associated with H. magnipapillata. Comparisons of the Hydra genome to the genomes of other animals shed light on the evolution of epithelia, contractile tissues, developmentally regulated transcription factors, the Spemann–Mangold organizer, pluripotency genes and the neuromuscular junction. PMID:20228792

  17. Evolution of Dusty Disks in Nearby Young Stellar Groups

    CERN Document Server

    Jayawardhana, R

    2001-01-01

    Given their proximity and age differences, nearby groups of young stars are valuable laboratories for investigations of disk evolution and diversity. The estimated 10-Myr age of groups like the TW Hydrae Association provides a strong constraint on disk evolution timescales and fills a significant gap in the age sequence between 1-Myr-old T Tauri stars in molecular clouds and 50-Myr-old nearby open clusters. I review the results of recent and on-going studies of dusty disks in three nearby groups --TW Hya, $\\eta$ Cha and MBM 12-- that suggest rapid evolution of inner disks. However, it is unlikely that there is a universal evolutionary timescale for protoplanetary disks, especially when the influence of companion stars is taken into account.

  18. Young Stars with SALT

    Science.gov (United States)

    Riedel, Adric R.; Alam, Munazza K.; Rice, Emily L.; Cruz, Kelle L.; Henry, Todd J.

    2017-05-01

    We present a spectroscopic and kinematic analysis of 79 nearby M dwarfs in 77 systems. All of these dwarfs are low-proper-motion southern hemisphere objects and were identified in a nearby star survey with a demonstrated sensitivity to young stars. Using low-resolution optical spectroscopy from the Red Side Spectrograph on the South African Large Telescope, we have determined radial velocities, H-alpha, lithium 6708 Å, and potassium 7699 Å equivalent widths linked to age and activity, and spectral types for all of our targets. Combined with astrometric information from literature sources, we identify 44 young stars. Eighteen are previously known members of moving groups within 100 pc of the Sun. Twelve are new members, including one member of the TW Hydra moving group, one member of the 32 Orionis moving group, 9 members of Tucana-Horologium, one member of Argus, and two new members of AB Doradus. We also find 14 young star systems that are not members of any known groups. The remaining 33 star systems do not appear to be young. This appears to be evidence of a new population of nearby young stars not related to the known nearby young moving groups. Based on observations made with the Southern African Large Telescope (SALT).

  19. Keck Adaptive Optics Imaging of Nearby Young Stars: Detection of Close Multiple Systems

    CERN Document Server

    Brandeker, A; Najita, J R; Brandeker, Alexis; Jayawardhana, Ray; Najita, Joan

    2003-01-01

    Using adaptive optics on the Keck II 10-meter telescope on Mauna Kea, we have surveyed 24 of the nearest young stars known in search of close companions. Our sample includes members of the MBM 12 and TW Hydrae young associations and the classical T Tauri binary UY Aurigae in the Taurus star-forming region. We present relative photometry and accurate astrometry for 10 close multiple systems. The multiplicity frequency in the TW Hydrae and MBM 12 groups are high in comparison to other young regions, though the significance of this result is low because of the small number statistics. We resolve S 18 into a triple system including a tight 63 mas (projected separation of 17 AU at a distance of 275 pc) binary for the first time, with a hierarchical configuration reminiscent of VW Chamaeleontis and T Tauri. Another tight binary in our sample -- TWA 5Aab (54 mas or 3 AU at 55 pc) -- offers the prospect of dynamical mass measurement using astrometric observations within a few years, and thus could be important for te...

  20. The Hydra drawings: digital imperfection

    DEFF Research Database (Denmark)

    Peder Pedersen, Claus

    2008-01-01

    Teksten diskuterer den digitale tegnings potenitaler med udgangspunkt i et kunstnerisk udviklingsarbejde gennemført på den græske ø Hydra. Den fokuserer på tegningens historiske betydning som medie for arkitektonisk formgivning og diskuterer muligheden for at gentænke forholdet mellem det åbent...

  1. Read-through proteins of group 4 RNA bacteriophages TW19 and TW28. [Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Aoi, T.; Kaesberg, P.

    1976-10-01

    Group 4 phages TW19 and TW28 of Escherichia coli possess a read-through (IIb) protein, although group 2 phage GA does not. This may have implications concerning the evolution and classification of RNA phages.

  2. On the structure of the transition disk around TW Hya

    CERN Document Server

    Menu, J; Henning, T; Chandler, C J; Linz, H; Benisty, M; Lacour, S; Min, M; Waelkens, C; Andrews, S M; Calvet, N; Carpenter, J M; Corder, S A; Deller, A T; Greaves, J S; Harris, R J; Isella, A; Kwon, W; Lazio, J; Bouquin, J -B Le; Ménard, F; Mundy, L G; Pérez, L M; Ricci, L; Sargent, A I; Storm, S; Testi, L; Wilner, D J

    2014-01-01

    For over a decade, the structure of the inner cavity in the transition disk of TW Hydrae has been a subject of debate. Modeling the disk with data obtained at different wavelengths has led to a variety of proposed disk structures. Rather than being inconsistent, the individual models might point to the different faces of physical processes going on in disks, such as dust growth and planet formation. Our aim is to investigate the structure of the transition disk again and to find to what extent we can reconcile apparent model differences. A large set of high-angular-resolution data was collected from near-infrared to centimeter wavelengths. We investigated the existing disk models and established a new self-consistent radiative-transfer model. A genetic fitting algorithm was used to automatize the parameter fitting. Simple disk models with a vertical inner rim and a radially homogeneous dust composition from small to large grains cannot reproduce the combined data set. Two modifications are applied to this sim...

  3. Ice-related landforms in Hydrae chasma, Mars

    Science.gov (United States)

    Baioni, Davide; Tramontana, Mario

    2016-04-01

    Hydrae Chasma is one of the smaller chasma of Valles Marineris. It is a circular depression approximately 50 kilometers across and 4 kilometers deep, located to the north of Coprates Chasma and south of Juventae Chasma A morphological survey of Hydrae Chasma through an analysis of the available Mars images was performed. The features of the landforms were investigated through an integrated analysis of Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) data. Landforms interpreted as due to ice-related processes, resembling similarly ice-related landforms found both in the cold-climate non glacial regions of the Earth, and putatively in other areas of Mars, was observed. These landforms are attributed to the presence of ground ice and/or ice-melting processes reflect significant climatic changes and different climatic conditions than those existing now. Moreover, they appear to display young erosional age, suggesting that are probably of Amazonian age.

  4. Gas and dust in the TW Hydrae association as seen by the Herschel Space Observatory

    NARCIS (Netherlands)

    Riviere-Marichalar, P.; Pinte, C.; Barrado, D.; Thi, W. F.; Eiroa, C.; Kamp, I.; Montesinos, B.; Donaldson, J.; Augereau, J. C.; Huelamo, N.; Roberge, A.; Ardila, D.; Sandell, G.; Williams, J. P.; Dent, W. R. F.; Menard, F.; Lillo-Box, J.; Duchene, G.

    2013-01-01

    Context. Circumstellar discs are the places where planets form, therefore knowledge of their evolution is crucial for our understanding of planet formation. The Herschel Space Observatory is providing valuable data for studying disc systems, thanks to its sensitivity and wavelength coverage. This pa

  5. Young Stars with SALT

    CERN Document Server

    Riedel, Adric R; Rice, Emily L; Cruz, Kelle L; Henry, Todd J

    2016-01-01

    We present a spectroscopic and kinematic analysis of 79 nearby M dwarfs in 77 systems. All are low-proper-motion southern hemisphere objects and were identified in a nearby star survey with a demonstrated sensitivity to young stars. Using low-resolution optical spectroscopy from the Red Side Spectrograph (RSS) on the South African Large Telescope (SALT), we have determined radial velocities, H-alpha, Lithium 6708\\AA, and Potassium 7699\\AA~equivalent widths linked to age and activity, and spectral types for all our targets. Combined with astrometric information from literature sources, we identify 44 young stars. Eighteen are previously known members of moving groups within 100 parsecs of the Sun. Twelve are new members, including one member of the TW Hydra moving group, one member of the 32 Orionis moving group, nine members of Tucana-Horologium, one member of Argus, and two new members of AB Doradus. We also find fourteen young star systems that are not members of any known groups. The remaining 33 star syst...

  6. Masses of Nix and Hydra

    CERN Document Server

    Tholen, David J; Grundy, William M; Elliott, Garrett T

    2007-01-01

    A four-body orbit solution for the Pluto system yields GM values of 870.3 +/- 3.7, 101.4 +/- 2.8, 0.039 +/- 0.034, and 0.021 +/- 0.042 km3 sec-2 for Pluto, Charon, Nix, and Hydra, respectively. Assuming a Charon-like density of 1.63 gm cm-3, the implied diameters for Nix and Hydra are 88 and 72 km, leading to visual geometric albedos of 0.08 and 0.18, respectively, though with considerable uncertainty. The eccentricity of Charon's orbit has a significant nonzero value; however, the 0.030 +/- 0.009 deg yr-1 rate at which the line of apsides precesses is insufficient to explain the difference in the longitude of periapsis seen in the orbits fitted to the 1992-1993 and 2002-2003 data sets. The mean orbital periods for Hydra, Nix, and Charon are in the ratios of 6.064 +/- 0.006 : 3.991 +/- 0.007 : 1, but we have not identified any resonant arguments that would indicate the existence of a mean motion resonance between any pairs of satellites.

  7. Coexistence of neuropeptides in hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J

    1983-01-01

    Using a technique for simultaneous visualisation of two antigens in one section, oxytocin-like immunoreactivity has been found to coexist with bombesin-like immunoreactivity in neurons of the basal disk, gastric region and tentacles of hydra. Neurons with oxytocin-like immunoreactivity in peduncle...... and hypostome, on the other hand, have little or no bombesin-like material. Oxytocin-like immunoreactivity never coexists with FMRFamide-immunoreactivity. The neurons with oxytocin- and FMRFamide-like immunoreactivity, however, are often found to be closely intermingled. The results show that coexistence...

  8. + 6 TEKSTER. KARTOGRAFI HYDRA 2013 #3

    DEFF Research Database (Denmark)

    Dinesen, Cort Ross

    2013-01-01

    +6 TEKSTER #3 indeholder en række indlæg, der er relateret til 14 NYE LANDSKABER/HYDRA 9, 2012 #1. Arbejdet med topologien og kartografien omkring tre urbane udsnit i Berlin, Paris og Tokyo har ført til en række udgivelser i GRID og følges op her med en række betragtninger, der perspektiverer denne...... at frembringe de baner, vi må tænke videre i. Denne serie af publikationer rummer også 10 NYE LANDSKABER/HYDRA 10 #2, 2013 og planlægges at blive fulgt op med et HYDRA 11 #4 i 2014. HYDRA refererer til en ø i Grækenland, der siden 2004 har dannet rammen om en sommerskole, der er optaget af KARTOGRAFI, MORFOLOGI...

  9. 爱普生EMP-TW2000

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    爱普生EMP-TW2000是爱普生家用投影机中规格最高的一款产品。它具有1600流明的高亮度,两组HDMI接口。EMP-TW2000采用爱普生最新研发的0.74英寸C2Fine技术的D6液晶面板,C2 FINE技术中独有的VA(垂直取向)模式,能大幅度地减少光泄漏,

  10. Isolation of four novel neuropeptides, the hydra-RFamides I-IV, from Hydra magnipapillata

    DEFF Research Database (Denmark)

    Moosler, A; Rinehart, K L; Grimmelikhuijzen, C J

    1996-01-01

    Using a radioimmunoassay for the sequence Arg-Phe-NH2 (RFamide), we have isolated four novel peptides from extracts of Hydra magnipapillata:......Using a radioimmunoassay for the sequence Arg-Phe-NH2 (RFamide), we have isolated four novel peptides from extracts of Hydra magnipapillata:...

  11. Hydra constitutively expresses transcripts involved in vertebrate neural differentiation

    Indian Academy of Sciences (India)

    Sandipan Chatterjee; Shweta Lahudkar; N N Godbole; Surendra Ghaskadbi

    2001-06-01

    The diploblastic Hydra is among the most primitive multicellular organisms. Using cross-hybridization with Xenopus probes, noggin-like transcripts were detected in the hypostome and basal disc of adult Hydra (Pelmatohydra oligactis), regions with properties similar to that of the amphibian organizer. This points to the possibility of a close molecular similarity between the Xenopus and Hydra organizers. The constitutive expression of a noggin-like gene in Hydra may be responsible for its regenerative capacity.

  12. Generation of Transgenic Hydra by Embryo Microinjection

    Science.gov (United States)

    Juliano, Celina E.; Lin, Haifan; Steele, Robert E.

    2014-01-01

    As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among multicellular animals. Hydra is used as a model for the study of regeneration, pattern formation, and stem cells. However, research efforts have been hampered by lack of a reliable method for gene perturbations to study molecular function. The development of transgenic methods has revitalized the study of Hydra biology1. Transgenic Hydra allow for the tracking of live cells, sorting to yield pure cell populations for biochemical analysis, manipulation of gene function by knockdown and over-expression, and analysis of promoter function. Plasmid DNA injected into early stage embryos randomly integrates into the genome early in development. This results in hatchlings that express transgenes in patches of tissue in one or more of the three lineages (ectodermal epithelial, endodermal epithelial, or interstitial). The success rate of obtaining a hatchling with transgenic tissue is between 10% and 20%. Asexual propagation of the transgenic hatchling is used to establish a uniformly transgenic line in a particular lineage. Generating transgenic Hydra is surprisingly simple and robust, and here we describe a protocol that can be easily implemented at low cost. PMID:25285460

  13. Is TW Pictoris really an intermediate polar?

    CERN Document Server

    Norton, A J

    1998-01-01

    We present the results of a long ROSAT HRI observation of the candidate intermediate polar TW Pic. The power spectrum shows no sign of either the previously proposed white dwarf spin period or the proposed binary orbital period (1.996 hr and 6.06 hr respectively). The limits to the X-ray modulation are less than 0.3% in each case. In the absence of a coherent X-ray pulsation, the credentials of TW Pic for membership of the intermediate polar subclass must be suspect. We further suggest that the true orbital period of the binary may be the shorter of the two previously suggested, and that the longer period may represent a quasi-periodic phenomenon associated with the accretion disc.

  14. Close Companions to Nearby Young Stars from Adaptive Optics Imaging on VLT and Keck

    Science.gov (United States)

    Haisch, Karl E.; Jayawardhana, Ray; Brandeker, Alexis; Mardones, Diego

    We report the results of VLT and Keck adaptive optics surveys of known members of the η Chamaeleontis, MBM 12, and TW Hydrae (TWA) associations to search for close companions. The multiplicity statistics of η Cha, MBM 12, and TWA are quite high compared with other clusters and associations, although our errors are large due to small number statistics. We have resolved S18 in MBM 12 and RECX 9 in η Cha into triples for the first time. The tight binary TWA 5Aab in the TWA offers the prospect of measuring the dynamical masses of both components as well as an independent distance to the system within a few years. The AO detection of the close companion to the nearby young star χ1 Orionis, previously inferred from radial velocity and astrometric observations, has already made it possible to derive the dynamical masses of that system without any astrophysical assumption.

  15. Close Companions to Nearby Young Stars from Adaptive Optics Imaging on VLT and Keck

    CERN Document Server

    Haisch, K E; Brandeker, A; Mardones, D; Jr., Karl E. Haisch; Jayawardhana, Ray; Brandeker, Alexis; Mardones, Diego

    2003-01-01

    We report the results of VLT and Keck adaptive optics surveys of known members of the Eta Chamaeleontis, MBM 12, and TW Hydrae (TWA) associations to search for close companions. The multiplicity statistics of Eta Cha, MBM 12, and TWA are quite high compared with other clusters and associations, although our errors are large due to small number statistics. We have resolved S18 in MBM 12 and RECX 9 in Eta Cha into triples for the first time. The tight binary TWA 5Aab in the TWA offers the prospect of measuring the dynamical masses of both components as well as an independent distance to the system within a few years. The AO detection of the close companion to the nearby young star Chi^1 Orionis, previously inferred from radial velocity and astrometric observations, has already made it possible to derive the dynamical masses of that system without any astrophysical assumption.

  16. Searching for Young M Dwarfs with GALEX

    CERN Document Server

    Shkolnik, Evgenya L; Reid, Iain Neill; Dupuy, Trent; Weinberger, Alycia

    2010-01-01

    The census of young moving groups in the solar neighborhood is significantly incomplete in the low-mass regime. We have developed a new selection process to find these missing members based on the GALEX All-Sky Imaging Survey (AIS). For stars with spectral types later than K5 (R - J >= 1.5) and younger than ~300 Myr, we show that near-UV (NUV) and far-UV (FUV) emission is greatly enhanced above the quiescent photosphere, analogous to the enhanced X-ray emission of young low-mass stars seen by ROSAT but detectable to much larger distances with GALEX. By combining GALEX data with optical (HST Guide Star Catalog) and near-IR (2MASS) photometry, we identified an initial sample of 34 young M dwarf candidates in a 1000 sq. deg. region around the 10-Myr TW Hydra Association (TWA). Low-resolution spectroscopy of 30 of these found 16 which had H_alpha in emission, which were then followed-up at high resolution to search for spectroscopic evidence of youth and to measure their radial velocities. Four objects have low s...

  17. Evo-devo: Hydra raises its Noggin

    Indian Academy of Sciences (India)

    Kalpana Chandramore; Surendra Ghaskadbi

    2011-08-01

    Noggin, along with other secreted bone morphogenetic protein (BMP) inhibitors, plays a crucial role in neural induction and neural tube patterning as well as in somitogenesis, cardiac morphogenesis and formation of the skeleton in vertebrates. The BMP signalling pathway is one of the seven fundamental pathways that drive embryonic development and pattern formation in animals. Understanding its evolutionary origin and role in pattern formation is, therefore, important to evolutionary developmental biology (evo-devo).We have studied the evolutionary origin of BMP–Noggin antagonism in hydra, which is a powerful diploblastic model to study evolution of pattern-forming mechanisms because of the unusual cellular dynamics during its pattern formation and its remarkable ability to regenerate. We cloned and characterized the noggin gene from hydra and found it to exhibit considerable similarity with its orthologues at the amino acid level. Microinjection of hydra Noggin mRNA led to duplication of the dorsoventral axis in Xenopus embryos, demonstrating its functional conservation across the taxa. Our data, along with those of others, indicate that the evolutionarily conserved antagonism between BMP and its inhibitors predates bilateral divergence. This article reviews the various roles of Noggin in different organisms and some of our recent work on hydra Noggin in the context of evolution of developmental signalling pathways.

  18. The Hydra-k Partial Fields

    NARCIS (Netherlands)

    R. Pendavingh; S.H.M. van Zwam (Stefan)

    2010-01-01

    htmlabstractIn the paper "Confinement of matroid representations to subsets of partial fields" (arXiv:0806.4487) we introduced the Hydra-k partial fields to study quinary matroids with inequivalent representations. The proofs of some results on these partial fields require extensive computations.

  19. A sparse population of young stars in Cepheus

    Science.gov (United States)

    Klutsch, A.

    2010-12-01

    Once mixed in the ambient galactic plane stellar population, young stars are virtually indiscernible because neither their global photometric properties nor the presence of nearby gas can help to disentangle them from older ones. Nevertheless, the study of the RasTyc sample revealed 4 lithium-rich field stars displaying the same space motion, which are located within a few degrees from each other on the celestial sphere near the Cepheus-Cassiopeia complex and at a similar distance from the Sun. Both physical and kinematical indicators show that all these stars are young, with ages in the range 10-30 Ma. Multivariate analysis methods were used to select optical counterparts of XMM-Newton / ROSAT All-Sky Survey X-ray sources cross-identified with late-type stars around these 4 young stars. Recent intermediate- and high-resolution spectroscopic observations of this sample allowed to discover additional lithium-rich sources. The preliminary results show that some of them share the same space motion as the 4 original stars. They have properties rather similar to the members of the TW~Hydrae association, although they are slightly older and located in the northern hemisphere. Nearby young stars in the field are of great importance to understand the recent local history of star formation, as well as to give new insight into the process of star formation outside standard star-forming regions and to study the evolution of circumstellar discs.

  20. Two-color double-labeling in situ hybridization of whole-mount Hydra using RNA probes for five different Hydra neuropeptide preprohormones: evidence for colocalization

    DEFF Research Database (Denmark)

    Hansen, G N; Williamson, M; Grimmelikhuijzen, C J

    2000-01-01

    -terminal sequence Lys-Val-NH2 (Hydra-KVamide). The various Hydra-RFamides are synthesized by three different preprohormones: preprohormone-A, -B, and -C. The various Hydra-LWamides are synthesized by a single preprohormone (prepro-Hydra-LWamide), as is Hydra-KVamide (prepro-Hydra-KVamide). Using a wholemount double-labeling...... exists that expresses both preprohormones-A and preproHydra-KVamide mRNAs. The functional significance of this coexpression is unclear. This is the first report on the coexpression of two well-characterized preprohormones (yielding two well-characterized neurohormone families) in cnidarians. This report...

  1. Route to 100 TW Ti: Sapphire laser at repetitive mode

    Directory of Open Access Journals (Sweden)

    Teng Hao

    2013-11-01

    Full Text Available We demonstrated a 100 TW-class femtosecond Ti: sapphire laser running at repetition rate of 0.1 Hz by adding a stage amplifier in the 20 TW/10 Hz laser facility (XL-II. Pumping the new stage amplifier with the 25 J green Nd:glass laser, we successfully upgraded the laser energy to 3.4 J with duration of 29 fs, corresponding to a peak power of 117 TW.

  2. Isolation of a substance activating foot formation in hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Schaller, H C

    1977-01-01

    -forming potential of the tissue (2) It does not accelerate head regeneration, nor do the head factors of hydra discovered by Schaller (1973) and Berking (1977) accelerate foot regeneration. We propose that the foot-activating substance is a morphogen responsible for foot formation in hydra. The foot activator can...... be extracted from hydra tissue with methanol and separated from other known morphogens of hydra by gel filtration and ion-exchange chromatography. A substance with similar biological and physicochemical properties can be isolated from sea anemones....

  3. The effects of dopamine synthesis inhibitors and dopamine antagonists on regeneration in the hydra Hydra attenuata.

    Science.gov (United States)

    Ostroumova, T V; Markova, L N

    2002-01-01

    The effects of catecholamine synthesis inhibitors (alpha-methyltyrosine, 3-iodotyrosine, and alpha-methyl-DOPA) and dopamine receptor blockers (haloperidol and spiperone) on the regeneration of apical, gastral, and basal fragments of the hydra Hydra attenuata were studied. These experiments showed that alpha-methyltyrosine and 3-iodotyrosine significantly inhibited regeneration but did not produce morphological anomalies. Alpha-Methyl-DOPA produce less inhibition of regeneration, but induced ectopic tentacles and outgrowths in gastral regenerates. Haloperidol and spiperone had no significant effect on the rate of regeneration but induced significant numbers of morphogenetic anomalies in gastral regenerates. Apical and basal regenerates, which retained their natural organizers (the head and base respectively) never yielded morphogenetic anomalies in the presence of either dopamine receptor blockers or dopamine synthesis inhibitors. The possible role of neurotransmitters. particularly dopamine, in morphogenesis in hydras is discussed.

  4. Bombesin-like immunoreactivity in the nervous system of hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Dockray, G J; Yanaihara, N

    1981-01-01

    With immunocytochemical methods, nerve cells have been detected in Hydra attenuata containing bombesin-like immunoreactivity. These nerve cells are located in ectoderm of all body regions of the animal and are especially abundant in basal disk and tentacles. Radioimmunoassay of extracts of hydra ...

  5. Neurotensin-like immunoreactivity in the nervous system of hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Carraway, R E; Rökaeus, A

    1981-01-01

    Neurotensin-like immunoreactivity is found in nerve fibers present in all body regions of hydra. The nerve fibers are especially numerous in the ectoderm at the bases of the tentacles and in the ectoderm at a site just above the foot. Radioimmunoassays of acetic-acid extracts of hydra, using vari...

  6. HYDRA: a decision support model for irrigation water management

    NARCIS (Netherlands)

    Jacucci, G.; Kabat, P.; Verrier, P.J.; Teixeira, J.L.; Steduto, P.; Bertanzon, G.; Giannerini, G.; Huygen, J.; Fernando, R.M.; Hooijer, A.A.; Simons, W.; Toller, G.; Tziallas, G.; Uhrik, C.; Broek, van den B.J.; Vera Munoz, J.; Yovchev, P.

    1995-01-01

    HYDRA introduces information modelling and decision-support systems (DSS) to farmers and authorities in European Mediterranean agriculture in order to improve irrigation practices at different levels. Key components of HYDRA-DSS are a hierarchical setof water balance and crop growth simulation

  7. Bombesin-like immunoreactivity in the nervous system of hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Dockray, G J; Yanaihara, N

    1981-01-01

    With immunocytochemical methods, nerve cells have been detected in Hydra attenuata containing bombesin-like immunoreactivity. These nerve cells are located in ectoderm of all body regions of the animal and are especially abundant in basal disk and tentacles. Radioimmunoassay of extracts of hydra...

  8. On the Origin of Pluto's Minor Moons, Nix and Hydra

    CERN Document Server

    Lithwick, Yoram

    2008-01-01

    How did Pluto's recently discovered minor moons form? Ward and Canup propose an elegant solution in which Nix and Hydra formed in the collision that produced Charon, then were caught into corotation resonances with Charon, and finally were transported to their current location as Charon migrated outwards. We show with numerical integrations that, if Charon's eccentricity is judiciously chosen, this scenario works beautifully for either Nix or Hydra. However, it cannot work for both Nix and Hydra simultaneously. To transport Nix, Charon's eccentricity must satisfy e_C 0.7 R_p/a_C > 0.04; otherwise migration would be faster than libration, and Hydra would slip out of resonance. These two restrictions conflict. Having ruled out this scenario, we suggest an alternative: that many small bodies were captured from the nebular disk, and they were responsible for forming, migrating and damping Nix and Hydra. If this is true, small moons could be common around large Kuiper belt objects.

  9. HYDRA: a Java library for Markov Chain Monte Carlo

    Directory of Open Access Journals (Sweden)

    Gregory R. Warnes

    2002-03-01

    Full Text Available Hydra is an open-source, platform-neutral library for performing Markov Chain Monte Carlo. It implements the logic of standard MCMC samplers within a framework designed to be easy to use, extend, and integrate with other software tools. In this paper, we describe the problem that motivated our work, outline our goals for the Hydra pro ject, and describe the current features of the Hydra library. We then provide a step-by-step example of using Hydra to simulate from a mixture model drawn from cancer genetics, first using a variable-at-a-time Metropolis sampler and then a Normal Kernel Coupler. We conclude with a discussion of future directions for Hydra.

  10. Three different prohormones yield a variety of Hydra-RFamide (Arg-Phe-NH2) neuropeptides in Hydra magnipapillata

    DEFF Research Database (Denmark)

    Darmer, D; Hauser, F; Nothacker, H P;

    1998-01-01

    from H. magnipapillata, each of which gives rise to a variety of RFamide neuropeptides. Preprohormone A contains one copy of unprocessed Hydra-RFamide I (QWLGGRFG), II (QWFNGRFG), III/IV [(KP)HLRGRFG] and two putative neuropeptide sequences (QLMSGRFG and QLMRGRFG). Preprohormone B has the same general...... organization as preprohormone A, but instead of unprocessed Hydra-RFamide III/IV it contains a slightly different neuropeptide sequence [(KP)HYRGRFG]. Preprohormone C contains one copy of unprocessed Hydra-RFamide I and seven additional putative neuropeptide sequences (with the common N-terminal sequence QWF....../LSGRFGL). The two Hydra-RFamide II copies (in preprohormones A and B) are preceded by Thr residues, and the single Hydra-RFamide III/IV copy (in preprohormone A) is preceded by an Asn residue, confirming that cnidarians use unconventional processing signals to generate neuropeptides from their precursor proteins...

  11. A new species of green hydra (Hydrozoa: Hydrida) from China.

    Science.gov (United States)

    Wang, An-Tai; Deng, Li; Lai, Jing-Qi; Li, Juan

    2009-09-01

    A new species of green freshwater hydra (Cnidaria, Hydrozoa: Hydrida), Hydra sinensis, is described from Guangdong Province, China. The chief distinction between H. sinensis sp. nov. and three other green hydras (H. hadleyi, H. viridissima, and H. plagiodesmica) is in the holotrichous isorhizae. Hydra sinensis sp. nov. differs from H. plagiodesmica in the shape of the holotrichous isorhlzae, and from H. viridissima and H. hadleyi in the tubule of the capsule of the holotrichous isorhlzae. The capsule tubule colls two times in 86% and three times in 14% of holotrlchous isorhlzae (n=50) In H. sinensis sp. nov.; we observed no tubules coiling four times. In contrast, the capsule tubule coils three or four times in H. viridissima and H. hadleyi, and no tubules coiling two times have been reported. In addition, holotrichous isorhlzae, which are mainly located around the hypostome, are sparse in the tentacles of H. sinensis sp. nov., whereas the majority of holotrichous isorhlzae is located on the tentacles in most other hydras. A molecular phylogenetic analysis using the nuclear small subunlt (18S) ribosomal RNA gene Indicated a close relationship between H. sinensis and H. viridissima. Hydra viridissima did not group within a clade of four Individuals of H. sinensis, Indicating a possible sister-species relationship between the two species. Morphological characters in combination with the molecular phylogenetic evidence support Hydra sinensis as a new species.

  12. The Pulsation Spectrum of VX Hydrae

    Science.gov (United States)

    Templeton, M. R.; Samolyk, G.; Dvorak, S.; Poklar, R.; Butterworth, N.; Gerner, H.

    2009-10-01

    We present the results of a two-year, multisite observing campaign investigating the high-amplitude δ Scuti star VX Hydrae during the 2006 and 2007 observing seasons. The final data set consists of nearly 8500 V-band observations spanning HJD 2453763.6 to 2454212.7 (2006 January 28 to 2007 April 22). Separate analyses of the two individual seasons of data yield 25 confidently detected frequencies common to both data sets, of which two are pulsation modes, and the remaining 23 are Fourier harmonics or beat frequencies of these two modes. The 2006 data set had five additional frequencies with amplitudes less than 1.5 mmag, and the 2007 data had one additional frequency. Analysis of the full 2006–2007 data set yields 22 of the 25 frequencies found in the individual seasons of data. There are no significant peaks in the spectrum other than these between 0 and 60 cycles day-1. The frequencies of the two main pulsation modes derived from the 2006 and 2007 observing seasons individually do not differ at the level of 3σ, and thus we find no conclusive evidence for period change over the span of these observations. However, the amplitude of changed significantly between the two seasons, while the amplitude of remained constant; amplitudes of the Fourier harmonics and beat frequencies of f1 also changed. Similar behavior was seen in the 1950s, and it is clear that VX Hydrae undergoes significant amplitude changes over time.

  13. No junctional communication between epithelial cells in hydra

    DEFF Research Database (Denmark)

    de Laat, S W; Tertoolen, L G; Grimmelikhuijzen, C J

    1980-01-01

    junctions between epithelial cells of hydra. However, until now, there has been no report published on whether these junctions enable the epithelial cells to exchange molecules of small molecular weight, as has been described in other organisms. Therefore we decided to investigate the communicative...... properties of the junctional membranes by electrophysiological methods and by intracellular-dye iontophoresis. We report here that no electrotonic coupling is detectable between epithelial cells of Hydra attenuata in: (1) intact animals, (2) head-regenerating animals, (3) cell re-aggregates, and (4) hydra...

  14. Comparison of TW2 and TW3 skeletal age differences in a Brazilian population Estudo comparativo das idades ósseas estimadas pelos métodos TW2 e TW3 numa população brasileira

    Directory of Open Access Journals (Sweden)

    Ana Isabel Ortega

    2006-04-01

    Full Text Available OBJECTIVE: The aim of this study was to determine the differences between the skeletal ages estimated by TW2 and TW3 methods through their RUS and Carpal systems. MATERIAL AND METHODS: A sample of two hundred and forty hand and wrist radiographs of male and female Brazilian children aged 84-199 months was evaluated by five observers. The Dunnet test was performed for statistical analysis. RESULTS: Results showed higher skeletal ages estimated by TW2RUS than TW3RUS and Carpal for both genders. For girls a statistically significant difference (pOBJETIVO: O objetivo deste estudo foi determinar as diferenças entre as idades esqueletais estimadas pelos métodos TW2 e TW3, usando os sistemas RUS e Carpal. MATERIAL E MÉTODOS: Uma amostra de 240 radiografias de mão e punho de crianças brasileiras de ambos os sexos com idade cronológica entre 84 e 199 meses foram avaliadas por cinco observadores. Para análise estatística dos dados foi aplicado o Teste de Dunnet. RESULTADOS: Os resultados demonstraram que as idades esqueletais estimadas pelo método TW2RUS foram mais avançadas que aquelas estimadas pelos métodos TW3RUS e Carpal, para ambos os sexos. Para o sexo feminino, uma diferença estatisticamente significante (p<0,05 foi observada entre os métodos TW2RUS e TW3RUS em todas as faixas etárias estudadas. No sexo masculino, essa diferença foi observada a partir de 108 meses em diante. Em geral, idades esqueletais estimadas pelo método RUS são maiores que a idade cronológica e também maiores que a idade esqueletal estimada pelo método Carpal em ambos os sexos. A superestimativa da idade cronológica é menor quando se aplica o método TW3RUS do que ao se utilizar o método TW2RUS, e esse último sistema mostrou uma diferença estatisticamente significante em relação a idade cronológica em todas as faixas etárias das meninas, enquanto para os meninos isso foi observado apenas a partir dos 132 meses em diante. No sexo feminino, houve

  15. IR wireless cluster synapses of HYDRA very large neural networks

    Science.gov (United States)

    Jannson, Tomasz; Forrester, Thomas

    2008-04-01

    RF/IR wireless (virtual) synapses are critical components of HYDRA (Hyper-Distributed Robotic Autonomy) neural networks, already discussed in two earlier papers. The HYDRA network has the potential to be very large, up to 10 11-neurons and 10 18-synapses, based on already established technologies (cellular RF telephony and IR-wireless LANs). It is organized into almost fully connected IR-wireless clusters. The HYDRA neurons and synapses are very flexible, simple, and low-cost. They can be modified into a broad variety of biologically-inspired brain-like computing capabilities. In this third paper, we focus on neural hardware in general, and on IR-wireless synapses in particular. Such synapses, based on LED/LD-connections, dominate the HYDRA neural cluster.

  16. Evidence that polycystins are involved in Hydra cnidocyte discharge.

    Science.gov (United States)

    McLaughlin, Susan

    2017-03-01

    Like other cnidarians, the freshwater organism Hydra is characterized by the possession of cnidocytes (stinging cells). Most cnidocytes are located on hydra tentacles, where they are organized along with sensory cells and ganglion cells into battery complexes. The function of the battery complexes is to integrate multiple types of stimuli for the regulation of cnidocyte discharge. The molecular mechanisms controlling the discharge of cnidocytes are not yet fully understood, but it is known that discharge depends on extracellular Ca(2+) and that mechanically induced cnidocyte discharge can be enhanced by the presence of prey extracts and other chemicals. Experiments in this paper show that a PKD2 (polycystin 2) transient receptor potential (TRP) channel is expressed in hydra tentacles and bases. PKD2 (TRPP) channels belong to the TRP channel superfamily and are non-selective Ca(2+) channels involved in the transduction of both mechanical and chemical stimuli in other organisms. Non-specific PKD2 channel inhibitors Neo (neomycin) and Gd(3+) (gadolinium) inhibit both prey capture and cnidocyte discharge in hydra. The PKD2 activator Trip (triptolide) enhances cnidocyte discharge in both starved and satiated hydra and reduces the inhibition of cnidocyte discharge caused by Neo. PKD1 and 2 proteins are known to act together to transduce mechanical and chemical stimuli; in situ hybridization experiments show that a PKD1 gene is expressed in hydra tentacles and bases, suggesting that polycystins play a direct or indirect role in cnidocyte discharge.

  17. Studies on Male Antifertilitic and Immunomodulatory Effects of TW19

    Institute of Scientific and Technical Information of China (English)

    王作鹏; 王晓凤; 曹霖; 陆荣发; 赵世兴; 李晓玉; 顾芝萍

    2000-01-01

    TW 19 is a diterpene compound isolated from the root cortex of Tripterygium Wilfordii Hood. F. . Its effects on the immune function in ICR mice and the male fertility in SD rats, ICR mice and Kunming mice were evaluated. TW19 was given orally for 5 weeks. Then the antifertilitic effect was assessed by mating test. The results showed that EDso for anti-fertilitic were 332 μg/kg, 369. 9 μg/kg and 286. 8 μg/kg per day in SD rats, ICR mice and Kunming mice respectively. After the treatment of TW 19 at anti fertility dose for 5 weeks consecutively, the spermatozoa density and motility of trial animals reduced significantly. The weight of testis also declined in SD rats and Kunming mice, but no effects were observed in ICR mice. TW 19 inhibited proliferation of splenic T and B-lymphocytes of ICR mice in vitro and hence inhibited the antibody formation in vivo, but compared with T 4, the immunosuppressive effect of TW 19 was less obvious.

  18. EPSON(爱普生)EMP-TW2000

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    EPSON不久前推出的EMP—TW10003 LCD 1080p高清投影机自问世以来一直是人们关注的焦点之一,当热潮还未降温,EPSON紧接着又发布了最新的旗舰机种EMP-TW2000。EMP—TW2000同样是一款3LCD的1080P高清投影机,但采用了新开发的Crystal C1ear Fine(C2Fine)D7投影芯片,并且提供了对HDMI1.3a连接的支持,此外还运用了提高画面黑色表现的DEEPBLACK技术和大大扩展色域表现的x.v.Color技术,

  19. Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya: Constraining the disk gas mass

    CERN Document Server

    Thi, W F; Ménard, F; Woitke, P; Meeus, G; Riviere-Marichalar, P; Pinte, C; Howard, C D; Roberge, A; Sandell, G; Pascucci, I; Riaz, B; Grady, C A; Dent, W R F; Kamp, I; Duchêne, G; Augereau, J C; Pantin, E; Vandenbussche, B; Tilling, I; Williams, J P; Eiroa, C; Barrado, D; Alacid, J M; Andrews, S; Ardila, D R; Aresu, G; Brittain, S; Ciardi, D R; Danchi, W; Fedele, D; de Gregorio-Monsalvo, I; Heras, A; Huelamo, N; Krivov, A; Lebreton, J; Liseau, R; Martin-Zaidi, C; Mendigutía, I; Montesinos, B; Mora, A; Morales-Calderon, M; Nomura, H; Phillips, N; Podio, L; Poelman, D R; Ramsay, S; Rice, K; Solano, E; Walker, H; White, G J; Wright, G

    2010-01-01

    Planets are formed in disks around young stars. With an age of ~10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study their gaseous component. We aim to constrain the gas and dust mass of the circumstellar disk around TW Hya. We observed the fine-structure lines of [OI] and [CII] as part of the Open-time large program GASPS. We complement this with continuum data and ground-based 12CO 3-2 and 13CO 3-2 observations. We simultaneously model the continuum and the line fluxes with the 3D Monte-Carlo code MCFOST and the thermo-chemical code ProDiMo to derive the gas and dust masses. We detect the [OI] line at 63 micron. The other lines that were observed, [OI] at 145 micron and [CII] at 157 micron, are not detected. No extended emission has been found. Preliminary modeling of the photometric...

  20. Disks and outflows in the massive protobinary system W3(OH)TW

    CERN Document Server

    Zapata, Luis A; Rodríguez, Luis F; Girart, Josep M; Chen, Huei-Ru

    2011-01-01

    Sensitive and high angular resolution ($\\sim$ $0\\rlap.{"}7$) (sub)millimeter line and continuum observations of the massive star forming region W3(OH) made with the Submillimeter Array are presented. We report the first detection of two bipolar outflows emanating from the young and massive "Turner-Welch" [TW] protobinary system detected by the emission of the carbon monoxide. The outflows are massive (10 M$_\\odot$), highly-collimated (10$^\\circ$), and seem to be the extended molecular component of the strong radio jets and a 22 GHz maser water outflow energized also by the stars in the W3(OH)TW system. Observations of the 890 $\\mu$m continuum emission and the thermal emission of the CH$_3$OH might suggest the presence of two rotating circumstellar disk-like structures associated with the binary system. The disks-like structures have sizes of about 1500 AU, masses of a few M$_\\odot$ and appear to energize the molecular outflows and radio jets. We estimate that the young stars feeding the outflows and that are ...

  1. Constant mortality and fertility over age in Hydra.

    Science.gov (United States)

    Schaible, Ralf; Scheuerlein, Alexander; Dańko, Maciej J; Gampe, Jutta; Martínez, Daniel E; Vaupel, James W

    2015-12-22

    Senescence, the increase in mortality and decline in fertility with age after maturity, was thought to be inevitable for all multicellular species capable of repeated breeding. Recent theoretical advances and compilations of data suggest that mortality and fertility trajectories can go up or down, or remain constant with age, but the data are scanty and problematic. Here, we present compelling evidence for constant age-specific death and reproduction rates in Hydra, a basal metazoan, in a set of experiments comprising more than 3.9 million days of observations of individual Hydra. Our data show that 2,256 Hydra from two closely related species in two laboratories in 12 cohorts, with cohort age ranging from 0 to more than 41 y, have extremely low, constant rates of mortality. Fertility rates for Hydra did not systematically decline with advancing age. This falsifies the universality of the theories of the evolution of aging that posit that all species deteriorate with age after maturity. The nonsenescent life history of Hydra implies levels of maintenance and repair that are sufficient to prevent the accumulation of damage for at least decades after maturity, far longer than the short life expectancy of Hydra in the wild. A high proportion of stem cells, constant and rapid cell turnover, few cell types, a simple body plan, and the fact that the germ line is not segregated from the soma are characteristics of Hydra that may make nonsenescence feasible. Nonsenescence may be optimal because lifetime reproduction may be enhanced more by extending adult life spans than by increasing daily fertility.

  2. Orbits and masses in the young triple system TWA 5

    CERN Document Server

    Köhler, R; Petr-Gotzens, M G; Correia, S

    2013-01-01

    We aim to improve the orbital elements and determine the individual masses of the components in the triple system TWA 5. Five new relative astrometric positions in the H band were recorded with the adaptive optics system at the Very Large Telescope (VLT). We combine them with data from the literature and a measurement in the Ks band. We derive an improved fit for the orbit of TWA 5Aa-b around each other. Furthermore, we use the third component, TWA 5B, as an astrometric reference to determine the motion of Aa and Ab around their center of mass and compute their mass ratio. We find an orbital period of 6.03+/-0.01 years and a semi-major axis of 63.7+/-0.2 mas (3.2+/-0.1 AU). With the trigonometric distance of 50.1+/-1.8 pc, this yields a system mass of 0.9+/-0.1 Msun, where the error is dominated by the error of the distance. The dynamical mass agrees with the system mass predicted by a number of theoretical models if we assume that TWA5 is at the young end of the age range of the TW Hydrae association. We fin...

  3. T.W. Adorno e a psicologia social T.W. Adorno and social psychology

    Directory of Open Access Journals (Sweden)

    José Leon Crochík

    2008-08-01

    Full Text Available Neste ensaio, ressalta-se a importância da disciplina Psicologia Social na obra de T. W. Adorno e a concepção que formula acerca dessa disciplina. Esse autor defende que há uma nova forma de configuração dos indivíduos, expressada por atitudes e comportamentos individuais padronizados e por um ego frágil, facilmente cooptado por movimentos sociais totalitários. Tais indivíduos surgem em uma sociedade caracterizada por uma forma de dominação calcada na racionalidade administrativa e tecnológica. Para esse autor, a Psicologia Social deveria estudar esse objeto para que, com o esclarecimento produzido e difundido, os indivíduos possam resistir à adesão cega a movimentos sociais irracionais, tal como o fascismo, insistindo que a determinação desses movimentos não é individual, mas social.In this assay, the importance of Social Psychology discipline in the T.W. Adorno's work and the specific conception that he formulates about it are pointed out. He defends that there is a new way of individuals' configuration, expressed by standardized attitudes and their own behaviors, such as a fragile ego, which is easily co-opted by totalitarian social movements. Such individuals appear in a society characterized by a form of domination based on administrative and technological rationality. For that author, Social Psychology would have to study this issue so that, with the enlightenment achieved and diffused, the individuals are able to resist to the blind adhesion in irrational social movements, such as the fascism. Adorno empathized that the determination of these movements is not individual, but social.

  4. Spitzer Spectroscopy of the Transition Object TW Hya

    Science.gov (United States)

    2010-02-24

    the [NeII] line profile of TW Hya, which shows a 6 km s−1 blueshift in the emission centroid, as indicating an origin in a low-velocity...of high velocity phenomena such as magnetospheric infall would be indicated. If the lines are nar- row (> 30 km s−1) and/or with a small blueshift

  5. TwNC: a Multifaceted Dutch News Corpus

    NARCIS (Netherlands)

    Ordelman, Roeland; Jong, de Franciska; Hessen, van Arjan; Hondorp, Hendri

    2007-01-01

    This contribution describes the Twente News Corpus (TwNC), a multifaceted corpus for Dutch that is being deployed in a number of NLP research projects among which tracks within the Dutch national research programme MultimediaN, the NWO programme CATCH, and the Dutch-Flemish programme STEVIN. The de

  6. Die bisher beobachteten Ausbrueche der Zwergnova TW Vul

    Science.gov (United States)

    Wenzel, Klaus

    2016-01-01

    In the Season 2015, the Dwarf Nova TW Vul shows two outbursts. Both outbursts were discovered by Shawn Dvorak. In this publication I present the lightcurve of these observations since 2011 and the two outbursts of 2015. They are based on visual observations by Klaus Wenzel, CCD Observations of the BRT in Tenerife and CCD Observations by Shawn Dvorak (Florida USA).

  7. A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages

    CERN Document Server

    Kirkpatrick, J Davy; Barman, Travis S; Burgasser, Adam J; Looper, Dagny L; Tinney, C G; Gelino, Christopher R; Lowrance, Patrick J; Liebert, James; Carpenter, John M; Hillenbrand, Lynne A; Stauffer, John R

    2008-01-01

    Using a large sample of optical spectra of late-type dwarfs, we identify a subset of late-M through L field dwarfs that, because of the presence of low-gravity features in their spectra, are believed to be unusually young. From a combined sample of 303 field L dwarfs, we find observationally that 7.6+/-1.6% are younger than 100 Myr. This percentage is in agreement with theoretical predictions once observing biases are taken into account. We find that these young L dwarfs tend to fall in the southern hemisphere (Dec < 0 deg) and may be previously unrecognized, low-mass members of nearby, young associations like Tucana-Horologium, TW Hydrae, beta Pictoris, and AB Doradus. We use a homogeneously observed sample of roughly one hundred and fifty 6300-10000 Angstrom spectra of L and T dwarfs taken with the Low-Resolution Imaging Spectrometer at the W. M. Keck Observatory to examine the strength of the 6708-A Li I line as a function of spectral type and further corroborate the trends noted by Kirkpatrick et al. (...

  8. Effects of predation by Hydra (Cnidaria on cladocerans (Crustacea: Cladocera

    Directory of Open Access Journals (Sweden)

    Ligia Rivera-De la Parra

    2016-03-01

    Full Text Available Planktonic cladocerans have evolved different strategies to avoid predation from vertebrates; these include changes in morphology, behavior, physiology, and/or life-history traits. However, littoral cladocerans are better adapted to avoid invertebrate predation particularly from insect larvae by evolving morphological and physiological adaptations. Nevertheless, this has not been proven for some littoral predators such as Hydra. In this study, we provide quantitative data on how Hydra affects its zooplankton prey. We studied the predation behavior on Alona glabra, Ceridodaphnia dubia, Daphnia pulex, Daphnia cf. mendotae, Diaphanosoma birgei, Macrothrix triserialis, Moina macrocopa, Pleuroxus aduncus, Scapholeberis kingi, Simocephalus vetulus, Elaphoidella grandidieri, Brachionus rubens and Euchlanis dilatata. We also tested the indirect effect of allelochemicals from Hydra on the demography of Daphnia cf. mendotae. Littoral cladocerans are specially adapted to resist nematocyst injection and discharge of toxic substances from Hydra. A significant decrease in the population growth rate from 0.21 to 0.125 d-1 was observed at densities of 2 ind. ml-1. The role of carapace thickness as an adaptive strategy of littoral cladocerans against Hydra predation is discussed.

  9. Multi-wavelength spectrophotometry of EX Hydrae

    CERN Document Server

    Eisenbart, S; Reinsch, K; Gänsicke, B T

    2002-01-01

    We present phase-resolved infrared and optical spectrophotometry of the intermediate polar EX Hya supplemented by archival ultraviolet data. The spin-modulated emission from the accretion funnel and the emission from the accretion disk or ring contain substantial optically thin components. The white dwarf dominates the unmodulated flux in the ultraviolet and is identified by numerous absorption lines. Metal absorption in the accretion curtain may add to the observed spectral features. The secondary star is of spectral type M4+-1 and is detected by its ellipsoidal modulation. We derive a distance of 65+-11 pc which makes EX Hydrae one of the closest cataclysmic variables with a known distance. The luminosity derived from the integrated overall spectral energy distribution is 3x10^32 erg/s. The accretion rate of 3x10^15 g/s (for an 0.6 Msun white dwarf) is in reasonable agreement with the rates expected from angular momentum loss by gravitational radiation and from the observed spin-up of the white dwarf

  10. The pulsation spectrum of VX Hydrae

    CERN Document Server

    Templeton, M R; Dvorak, S; Poklar, R; Butterworth, N; Gerner, H

    2009-01-01

    We present the results of a two-year, multisite observing campaign investigating the high-amplitude delta Scuti star VX Hydrae during the 2006 and 2007 observing seasons. The final data set consists of nearly 8500 V-band observations spanning HJD 2453763.6 to 2454212.7 (2006 January 28 to 2007 April 22). Separate analyses of the two individual seasons of data yield 25 confidently-detected frequencies common to both data sets, of which two are pulsation modes, and the remaining 23 are Fourier harmonics or beat frequencies of these two modes. The 2006 data set had five additional frequencies with amplitudes less than 1.5 mmag, and the 2007 data had one additional frequency. Analysis of the full 2006-2007 data set yields 22 of the 25 frequencies found in the individual seasons of data. There are no significant peaks in the spectrum other than these between 0 and 60 c/d. The frequencies of the two main pulsation modes derived from the 2006 and 2007 observing seasons individually do not differ at the level of 3-si...

  11. A nearby young M dwarf with a wide, possibly planetary-mass companion

    CERN Document Server

    Deacon, Niall R; Murphy, Simon J

    2016-01-01

    We present the identification of two previously known young objects in the solar neighbourhood as a likely very wide binary. TYC 9486-927-1, an active, rapidly rotating early-M dwarf, and 2MASS J21265040-8140293, a low-gravity L3 dwarf previously identified as candidate members of the $\\sim$45 Myr old Tucana Horologium association (TucHor). An updated proper motion measurement of the L3 secondary, and a detailed analysis of the pair's kinematics in the context of known nearby, young stars, reveals that they share common proper motion and are likely bound. New observations and analyses reveal the primary exhibits Li 6708~\\AA~absorption consistent with M dwarfs younger than TucHor but older than the $\\sim$10 Myr TW Hydra association yielding an age range of 10-45 Myr. A revised kinematic analysis suggests the space motions and positions of the pair are closer to, but not entirely in agreement with, the $\\sim$24 Myr old $\\beta$ Pictoris moving group. This revised 10-45 Myr age range yields a mass range of 11.6--...

  12. Hydra and Niccolo Paganini (1782-1840)--two peas in a pod? The molecular basis of extracellular matrix structure in the invertebrate, Hydra.

    Science.gov (United States)

    Sarras, M P; Deutzmann, R

    2001-08-01

    The body wall of Hydra is organized as an epithelial bilayer with an intervening extracellular matrix (ECM). Molecular and biochemical analyses of Hydra ECM have established that it contains components similar to those seen in more complicated vertebrates such as human. In terms of biophysical parameters, Hydra ECM is highly flexible; a property that facilitates continuous movements along the organism's longitudinal and radial axis. A more rigid ECM, as in vertebrates, would not be compatible with this degree of movement. The flexible nature of Hydra ECM can now be explained in part by the unique structure of the organism's collagens. Interestingly, some aspects of the structural features of Hydra collagens mimic what is seen in Ehlers-Danlos syndrome, an inherited condition in humans that results in an abnormally flexible ECM that can be debilitating in extreme cases. This review will focus on structure-function relationships of the ECM of Hydra.

  13. Hymyc1 downregulation promotes stem cell proliferation in Hydra vulgaris.

    Directory of Open Access Journals (Sweden)

    Alfredo Ambrosone

    Full Text Available Hydra is a unique model for studying the mechanisms underlying stem cell biology. The activity of the three stem cell lineages structuring its body constantly replenishes mature cells lost due to normal tissue turnover. By a poorly understood mechanism, stem cells are maintained through self-renewal while concomitantly producing differentiated progeny. In vertebrates, one of many genes that participate in regulating stem cell homeostasis is the protooncogene c-myc, which has been recently identified also in Hydra, and found expressed in the interstitial stem cell lineage. In the present paper, by developing a novel strategy of RNA interference-mediated gene silencing (RNAi based on an enhanced uptake of small interfering RNAi (siRNA, we provide molecular and biological evidence for an unexpected function of the Hydra myc gene (Hymyc1 in the homeostasis of the interstitial stem cell lineage. We found that Hymyc1 inhibition impairs the balance between stem cell self renewal/differentiation, as shown by the accumulation of stem cell intermediate and terminal differentiation products in genetically interfered animals. The identical phenotype induced by the 10058-F4 inhibitor, a disruptor of c-Myc/Max dimerization, demonstrates the specificity of the RNAi approach. We show the kinetic and the reversible feature of Hymyc1 RNAi, together with the effects displayed on regenerating animals. Our results show the involvement of Hymyc1 in the control of interstitial stem cell dynamics, provide new clues to decipher the molecular control of the cell and tissue plasticity in Hydra, and also provide further insights into the complex myc network in higher organisms. The ability of Hydra cells to uptake double stranded RNA and to trigger a RNAi response lays the foundations of a comprehensive analysis of the RNAi response in Hydra allowing us to track back in the evolution and the origin of this process.

  14. Algal endosymbiosis in brown hydra: host/symbiont specificity.

    Science.gov (United States)

    Rahat, M; Reich, V

    1986-12-01

    Host/symbiont specificity has been investigated in non-symbiotic and aposymbiotic brown and green hydra infected with various free-living and symbiotic species and strains of Chlorella and Chlorococcum. Morphology and ultrastructure of the symbioses obtained have been compared. Aposymbiotic Swiss Hydra viridis and Japanese H. magnipapillata served as controls. In two strains of H. attenuata stable hereditary symbioses were obtained with Chlorococcum isolated from H. magnipapillata. In one strain of H. vulgaris, in H. oligactis and in aposymbiotic H. viridis chlorococci persisted for more than a week. Eight species of free-living Chlorococcum, 10 symbiotic and 10 free-living strains of Chlorella disappeared from the brown hydra within 1-2 days. In H. magnipapillata there was a graded distribution of chlorococci along the polyps. In hypostomal cells there were greater than 30 algae/cell while in endodermal cells of the mid-section or peduncle less than 10 algae/cell were found. In H. attenuata the algal distribution was irregular, there were up to five chlorocci/cell, and up to 20 cells/hydra hosted algae. In the dark most cells of Chlorococcum disappeared from H. magnipapillata and aposymbiotic hydra were obtained. Chlorococcum is thus an obligate phototroph, and host-dependent heterotrophy is not required for the preservation of a symbiosis. The few chlorococci that survived in the dark seem to belong to a less-demanding physiological strain. In variance with known Chlorella/H. viridis endosymbioses the chlorococci in H. magnipapillata and H. attenuata were tightly enveloped in the vacuolar membrane of the hosting cells with no visible perialgal space. Chlorococcum reproduced in these vacuoles and up to eight daughter cells were found within the same vacuole. We suggest that the graded or scant distribution of chlorococci in the various brown hydra, their inability to live in H. viridis and the inability of the various chlorellae to live in brown hydra are the

  15. FMRFamide-like immunoreactivity in the nervous system of Hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Dockray, G J; Schot, L P

    1982-01-01

    FMRFamide-like immunoreactivity has been localized in different parts of the hydra nervous system. Immunoreactivity occurs in nerve perikarya and processes in the ectoderm of the lower peduncle region near the basal disk, in the ectoderm of the hypostome and in the ectoderm of the tentacles....... The immunoreactive nerve perikarya in the lower peduncle region form ganglion-like structures. Radioimmunoassays of extracts of hydra gave displacement curves parallel to standard FMRFamide and values of at least 8 pmol/gram wet weight of FMRFamide-like immunoreactivity. The immunoreactive material eluted from...

  16. FMRFamide-like immunoreactivity in the nervous system of Hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Dockray, G J; Schot, L P

    1982-01-01

    FMRFamide-like immunoreactivity has been localized in different parts of the hydra nervous system. Immunoreactivity occurs in nerve perikarya and processes in the ectoderm of the lower peduncle region near the basal disk, in the ectoderm of the hypostome and in the ectoderm of the tentacles...

  17. HydraPower out to make a big bang

    CERN Multimedia

    Revill, John

    2006-01-01

    "An engineering company has provided equipment for a £1.3 billion international project to recreate the conditions of the 'Big Bang". Garry Williams, technical director of hydraPower dynamics, has been asked to return to Switzerland by CERN."

  18. The Origin of Mucosal Immunity: Lessons from the Holobiont Hydra

    Directory of Open Access Journals (Sweden)

    Katja Schroder

    2016-11-01

    Full Text Available Historically, mucosal immunity—i.e., the portion of the immune system that protects an organism’s various mucous membranes from invasion by potentially pathogenic microbes—has been studied in single-cell epithelia in the gastrointestinal and upper respiratory tracts of vertebrates. Phylogenetically, mucosal surfaces appeared for the first time about 560 million years ago in members of the phylum Cnidaria. There are remarkable similarities and shared functions of mucosal immunity in vertebrates and innate immunity in cnidarians, such as Hydra species. Here, we propose a common origin for both systems and review observations that indicate that the ultimately simple holobiont Hydra provides both a new perspective on the relationship between bacteria and animal cells and a new prism for viewing the emergence and evolution of epithelial tissue-based innate immunity. In addition, recent breakthroughs in our understanding of immune responses in Hydra polyps reared under defined short-term gnotobiotic conditions open up the potential of Hydra as an animal research model for the study of common mucosal disorders.

  19. Astrometry and orbits of Nix, Kerberos, AND Hydra

    Energy Technology Data Exchange (ETDEWEB)

    Buie, Marc W. [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Grundy, William M. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Tholen, David J., E-mail: buie@boulder.swri.edu, E-mail: grundy@lowell.edu, E-mail: tholen@ifa.hawaii.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2013-12-01

    We present new Hubble Space Telescope observations of three of Pluto's outer moons, Nix, Kerberos, and Hydra. This work revises previously published astrometry of Nix and Hydra from 2002 to 2003. New data from a four-month span during 2007 include observations designed to better measure the positions of Nix and Hydra. A third data set from 2010 also includes data on Nix and Hydra as well as some pre-discovery observations of Kerberos. The data were fitted using numerical point-spread function (PSF) fitting techniques to get accurate positions but also to remove the extended wings of the Pluto and Charon PSFs when working on these faint satellites. The resulting astrometric data were fitted with two-body Keplerian orbits that are useful for short-term predictions of the future positions of these satellites for stellar occultation and for guiding encounter planning for the upcoming New Horizons flyby of the Pluto system. The mutual inclinations of the satellites are all within 0.°2 of the plane of Charon's orbit. The periods for all continue to show that their orbits are near but distinct from integer period ratios relative to Charon. Based on our results, the period ratios are Hydra:Charon = 5.98094 ± 0.00001, Kerberos:Charon = 5.0392 ± 0.0003, and Nix:Charon = 3.89135 ± 0.00001. Based on period ratios alone, there is a trend of increased distance from an integer period ratio with decreasing distance from Charon. Our analysis shows that orbital uncertainties for Nix and Hydra are now low enough to permit useful stellar occultation predictions and for New Horizons encounter planning. In 2015 July, our orbits predict a position error of 60 km for Nix and 38 km for Hydra, well below other limiting errors that affect targeting. The orbit for Kerberos, however, still needs a lot of work as its uncertainty in 2015 is quite large at 22,000 km based on these data.

  20. WISEA J114724.10-204021.3: A Free-Floating Planetary Mass Member of the TW Hya Association

    CERN Document Server

    Schneider, Adam C; Cushing, Michael C; Kirkpatrick, J Davy; Wright, Edward L

    2016-01-01

    We present WISEA J114724.10$-$204021.3, a young, low-mass, high probability member of the TW Hya association. WISEA J114724.10$-$204021.3 was discovered based on its red AllWISE color (W1$-$W2 = 0.63 mag) and extremely red 2MASS $J-K_{\\rm S}$ color ($>$ 2.64 mag), the latter of which is confirmed with near-infrared photometry from the VISTA Hemisphere Survey ($J-K_{\\rm S}$ = 2.57$\\pm$0.03). Follow-up near-infrared spectroscopy shows a spectral type of L7 $\\pm$ 1 as well as several spectroscopic indicators of youth. These include a peaked $H$-band shape and a steeper $K$-band slope, traits typically attributed to low surface gravity. The sky position, proper motion, and distance estimates of WISEA J114724.10$-$204021.3 are all consistent with membership in the $\\sim$10 Myr old TW Hya association. Using the age of the TW Hya association and evolutionary models, we estimate the mass of WISEA J114724.10$-$204021.3 to be 5$-$13 $M_{\\rm Jup}$, making it one of the youngest and lowest mass free-floating objects yet ...

  1. Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya. Constraining the disk gas mass

    Science.gov (United States)

    Thi, W.-F.; Mathews, G.; Ménard, F.; Woitke, P.; Meeus, G.; Riviere-Marichalar, P.; Pinte, C.; Howard, C. D.; Roberge, A.; Sandell, G.; Pascucci, I.; Riaz, B.; Grady, C. A.; Dent, W. R. F.; Kamp, I.; Duchêne, G.; Augereau, J.-C.; Pantin, E.; Vandenbussche, B.; Tilling, I.; Williams, J. P.; Eiroa, C.; Barrado, D.; Alacid, J. M.; Andrews, S.; Ardila, D. R.; Aresu, G.; Brittain, S.; Ciardi, D. R.; Danchi, W.; Fedele, D.; de Gregorio-Monsalvo, I.; Heras, A.; Huelamo, N.; Krivov, A.; Lebreton, J.; Liseau, R.; Martin-Zaidi, C.; Mendigutía, I.; Montesinos, B.; Mora, A.; Morales-Calderon, M.; Nomura, H.; Phillips, N.; Podio, L.; Poelman, D. R.; Ramsay, S.; Rice, K.; Solano, E.; Walker, H.; White, G. J.; Wright, G.

    2010-07-01

    Planets are formed in disks around young stars. With an age of ~10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study their gaseous component. We aim to constrain the gas and dust mass of the circumstellar disk around TW Hya. We observed the fine-structure lines of [O i] and [C ii] as part of the open-time large program GASPS. We complement this with continuum data and ground-based 12 CO 3-2 and 13CO 3-2 observations. We simultaneously model the continuum and the line fluxes with the 3D Monte-Carlo code MCFOST and the thermo-chemical code ProDiMo to derive the gas and dust masses. We detect the [O i] line at 63 μm. The other lines that were observed, [O i] at 145 μm and [C ii] at 157 μm, are not detected. No extended emission has been found. Preliminary modeling of the photometric and line data assuming [ 12CO] /[ 13CO] = 69 suggests a dust mass for grains with radius <1 mm of ~1.9 × 10-4 M⊙ (total solid mass of 3 × 10-3 M⊙) and a gas mass of (0.5-5) × 10-3 M⊙. The gas-to-dust mass may be lower than the standard interstellar value of 100. Herschel is an ESA space observatory with science instruments provided by Principal Investigator consortia. It is open for proposals for observing time from the worldwide astronomical community.Appendix is only available in electronic form at http://www.aanda.org

  2. PBFA Z: A 50 TW/5 MJ Electrical Generator

    Science.gov (United States)

    Spielman, R. B.

    1997-05-01

    PBFA Z is a new 50 TW/5 MJ short electrical driver located at Sandia National Laboratories. We use PBFA Z to magnetically-implode solid or plasma shells. These configurations are historically known as z pinches. The pulsed power design of PBFA Z(R. B. Spielman, et al., Proc. of the Ninth IEEE Pulsed Power Conf., Albuquerque, NM 1995) is based on conventional single-pulse Marx generator, water-line pulse-forming technology used on the earlier Saturn (D. D. Bloomquist, et al., Proc. of the Sixth IEEE Pulsed Power Conf., Arlington, VA edited by P. J. Turchi and B. H. Bernstein (IEEE, New York, 1987), p. 310) and PBFA II(B. N. Turman, et al., Proc. of the Fifth IEEE Pulsed Power Conf., Arlington, VA 1985, pp. 155) accelerators. PBFA Z stores 11.4 MJ in its 36 Marx generators, couples 5 MJ in a 50 TW/100 ns pulse to the output water transmission lines, and delivers 3.4 MJ and 40 TW of electrical energy to the z-pinch load. Depending on the initial load inductance and the implosion time, we attain a peak current of 16-20 MA with a rise time of 105 ns. Current is fed to the z-pinch load through self magnetically-insulated transmission lines (MITLs). Peak electric fields in the MITLs exceed 2 MV /cm. The current from the four independent conical disk MITLs is combined together in a double post-hole vacuum convolute with an efficiency greater than 95%. The measured system performance of the water transmission lines, the vacuum insulator stack, the MITLs, and the double post-hole vacuum convolute differed from preshot predictions by ~ 5%. Using a 2-cm radius and a 2-cm length tungsten wire array with 240, 7.5-=B5m diameter wires (4.1-mg mass) as the z-pinch load, we achieved x-ray powers of 160 TW and x-ray energies of 1.85 MJ as measured by x-ray diodes and resistive bolometry.

  3. Proton acceleration with a table-top TW laser

    Science.gov (United States)

    Seimetz, M.; Bellido, P.; Lera, R.; Ruiz-de la Cruz, A.; Mur, P.; Sánchez, I.; Galán, M.; Sánchez, F.; Roso, L.; Benlloch, J. M.

    2016-11-01

    We report on the recent demonstration of proton acceleration from a purpose-made Ti:Sapphire laser system. In the first successful series of autumn 2015, running at 2 TW peak power and 100 Hz diode pump rate, protons up to 0.7 MeV have been spectrally characterised. Subsequently, at increased laser pulse energy and improved contrast, we have obtained maximum particle energies around 1.7 MeV. These results, achieved in single-shot mode with a variety of thin foil targets, are an important step towards our aim of a stable, compact proton accelerator with high rate capacity.

  4. The young binary HD 102077: Orbit, spectral type, kinematics, and moving group membership

    CERN Document Server

    Wöllert, Maria; Reffert, Sabine; Schlieder, Joshua E; Mohler-Fischer, Maren; Köhler, Rainer; Henning, Thomas

    2014-01-01

    The K-type binary star HD 102077 was proposed as a candidate member of the TW Hydrae Association (TWA) which is a young (5-15 Myr) moving group in close proximity (~50 pc) to the solar system. The aim of this work is to verify this hypothesis by different means. We first combine diffraction-limited observations from the ESO NTT 3.5m telescope in SDSS-i' and -z' passbands and ESO 3.6m telescope in H-band with literature data to obtain a new, amended orbit fit, estimate the spectral types of both components, and reanalyse the Hipparcos parallax and proper motion taking the orbital motion into account. Moreover, we use two high-resolution spectra of HD 102077 obtained with the fibre-fed optical echelle spectrograph FEROS at the MPG/ESO 2.2m telescope to determine the radial velocity and the lithium equivalent width of the system. The trajectory of HD 102077 is well constrained and we derive a total system mass of $2.6 \\pm 0.8\\,$ M$_{\\odot}$ and a semi-major axis of $14.9 \\pm 1.6\\,$AU. From the i'-z' colours we i...

  5. Vertically illuminated TW-UTC photodiodes for terahertz generation

    Science.gov (United States)

    Barrientos Z., Claudio M.; Calle G., Victor H.; Alvarez, Jaime A.; Mena, F. Patricio; Vukusic, Josip; Stake, Jan; Michael, Ernest A.

    2012-09-01

    More efficient and powerful continuous-wave photonic mixers as terahertz sources are motivated by the need of more versatile local oscillators for submillimeter/terahertz receiver systems. Uni-Travelling Carrier (UTC) photodiodes are very prospective candidates for reaching this objective, but so far only have been reported as lumped-elements or as edge-illuminated optical-waveguide travelling-wave (TW) devices. To overcome the associated power limitations of those implementations, we are developing a novel implementation of the UTC photodiodes which combines a travelingwave photomixer with vertical velocity-matched illumination in a distributed structure. In this implementation called velocity-matched travelling-wave uni-travelling carrier photodiode, it is possible to obtain in-situ velocity matching of the beat-fringes of the two angled laser beams with the submm/THz-wave on the stripline. In this way, minimum frequency roll-off is achieved by tuning the angle between the two laser beams. A first design of these TW-UTC PDs from our Terahertz Photonics Laboratory at University of Chile has been micro-fabricated at the MC2 cleanroom facility at Chalmers Technical University.

  6. Strong tW Scattering at the LHC

    CERN Document Server

    Dror, Jeff Asaf; Salvioni, Ennio; Serra, Javi

    2016-01-01

    Deviations of the top electroweak couplings from their Standard Model values imply that certain amplitudes for the scattering of third generation fermions and longitudinally polarized vector bosons or Higgses diverge quadratically with momenta. This high-energy growth is a genuine signal of models where the top quark is strongly coupled to the sector responsible for electroweak symmetry breaking. We propose to profit from the high energies accessible at the LHC to enhance the sensitivity to non-standard top-$Z$ couplings, which are currently very weakly constrained. To demonstrate the effectiveness of the approach, we perform a detailed analysis of $tW \\to tW$ scattering, which can be probed at the LHC via $pp\\to t\\bar{t}Wj$. By recasting a CMS analysis at 8 TeV, we derive the strongest direct bounds to date on the $Ztt$ couplings. We also design a dedicated search at 13 TeV that exploits the distinctive features of the $t\\bar{t}Wj$ signal. Finally, we present other scattering processes in the same class that...

  7. Spitzer Spectroscopy of the Transition Object TW Hya

    CERN Document Server

    Najita, Joan R; Strom, Stephen E; Watson, Dan M; Pascucci, Ilaria; Hollenbach, David; Gorti, Uma; Keller, Luke

    2010-01-01

    We report sensitive Spitzer IRS spectroscopy in the 10-20 micron region of TW Hya, a nearby T Tauri star. The unusual spectral energy distribution of the source, that of a transition object, indicates that the circumstellar disk in the system has experienced significant evolution, possibly as a result of planet formation. The spectrum we measure is strikingly different from that of other classical T Tauri stars reported in the literature, displaying no strong emission features of water, acetylene, or HCN. The difference indicates that the inner planet formation region (within 5 AU) of the gaseous disk has evolved physically and/or chemically away from the classical T Tauri norm. Nevertheless, TW Hya does show a rich spectrum of emission features of atoms (HI, [NeII], and [NeIII]) and molecules (H2, OH, CO2, HCO+, and possibly CH3), some of which are also detected in classical T Tauri spectra. The properties of the neon emission are consistent with an origin for the emission in a disk irradiated by X-rays (wit...

  8. The innate immunity in the cnidarian Hydra vulgaris

    Directory of Open Access Journals (Sweden)

    B Altincicek

    2009-08-01

    Full Text Available Hydra vulgaris is currently receiving increased attention as a genetically tractable invertebrate model system for studying important processes of life such as the innate immune defense. Similar to complex animals, H. vulgaris polyps respond to injury by abrupt muscle contraction, by limited escape behavior, and by healing the damaged tissue. Simultaneously, cellular processes such as phagocytosis and programmed cell death as well as the massive production of antimicrobial peptides are induced. Recent studies identified several molecular pathways controlling these responses; however, the interdependence of innate immunity and, for example, regeneration and tissue remodeling is not well elucidated yet. H. vulgaris belongs to the Cnidaria representing the phylogenic sister group of bilaterian animals; hence, a better understanding of evolutionarily conserved as well as Hydra/Cnidaria-specific immune responses will provide deep insight into both origin and evolution of the animal innate immune system

  9. An EUV Study of the Intermediate Polar EX Hydrae

    CERN Document Server

    Belle, K E; Sirk, M; Huber, M E; Belle, Kunegunda E.; Howell, Steve B.; Sirk, Martin; Huber, Mark E.

    2002-01-01

    On 2000 May 5, we began a large multi-wavelength campaign to study the intermediate polar, EX Hydrae. The simultaneous observations from six satellites and four telescopes were centered around a one million second observation with EUVE. Although EX Hydrae has been studied previously with EUVE, our higher signal-to-noise observations present new results and challenge the current IP models. Previously unseen dips in the light curve are reminiscent of the stream dips seen in polar light curves. Also of interest is the temporal extent of the bulge dip; approximately 0.5 in phase, implying that the bulge extends over half of the accretion disk. We propose that the magnetic field in EX Hydrae is strong enough (a few MG) to begin pulling material directly from the outer edge of the disk, thereby forming a large accretion curtain which would produce a very broad bulge dip. This would also result in magnetically controlled accretion streams originating from the outer edge of the disk. We also present a period analysis...

  10. Hydra-TH Extensions for Multispecies and Thermosolutal Convection

    Energy Technology Data Exchange (ETDEWEB)

    Stagg, Alan K [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States; Yoon, Su-Jong [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    This report describes the Consortium for Advanced Simulation of Light Water Reactors (CASL) work conducted for completion of the Thermal Hydraulics Methods (THM) Level 3 Milestone THM.CFD.P11.02: Hydra-TH Extensions for Multispecies and Thermosolutal Convection. A critical requirement for modeling reactor thermal hydraulics is to account for species transport within the fluid. In particular, this capability is needed for modeling transport and diffusion of boric acid within water for emergency, reactivity-control scenarios. To support this need, a species transport capability has been implemented in Hydra-TH for binary systems (for example, solute within a solvent). A species transport equation is solved for the species (solute) mass fraction, and both thermal and solutal buoyancy effects are handled with specification of a Boussinesq body force. Species boundary conditions can be specified with a Dirichlet condition on mass fraction or a Neumann condition on diffusion flux. To enable enhanced species/fluid mixing in turbulent flow, the molecular diffusivity for the binary system is augmented with a turbulent diffusivity in the species transport calculation. The new capabilities are demonstrated by comparison of Hydra-TH calculations to the analytic solution for a thermosolutal convection problem, and excellent agreement is obtained.

  11. Evolutionary Analysis of Minor Histocompatibility Genes In Hydra

    KAUST Repository

    Aalismail, Nojood

    2016-05-01

    Hydra is a simple freshwater solitary polyp used as a model system to study evolutionary aspects. The immune response of this organism has not been studied extensively and the immune response genes have not been identified and characterized. On the other hand, immune response has been investigated and genetic analysis has been initiated in other lower invertebrates. In the present study we took initiative to study the self/nonself recognition in hydra and its relation to the immune response. Moreover, performing phylogenetic analysis to look for annotated immune genes in hydra gave us a potential to analyze the expression of minor histocompatibility genes that have been shown to play a major role in grafting and transplantation in mammals. Here we obtained the cDNA library that shows expression of minor histocompatibility genes and confirmed that the annotated sequences in databases are actually present. In addition, grafting experiments suggested, although still preliminary, that homograft showed less rejection response than in heterograft. Involvement of possible minor histocompatibility gene orthologous in immune response was examined by qPCR.

  12. Predicting Complex Organic Molecule Emission from TW Hya

    Science.gov (United States)

    Vissapragada, Shreyas; Walsh, Catherine

    2017-01-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) has significantly increased our ability to observe the rich chemical inventory of star and planet formation. ALMA has recently been used to detect CH3OH (methanol) and CH3CN (methyl cyanide) in protoplanetary disks; these molecules may be vital indicators of the complex organic ice reservoir in the comet-forming zone. We have constructed a physiochemical model of TW Hya, a well-studied protoplanetary disk, to explore the different formation mechanisms of complex ices. By running our model through a radiative transfer code and convolving with beam sizes appropriate for ALMA, we have obtained synthetic observations of methanol and methyl cyanide. Here, we compare and comment on these synthetic observations, and provide astrochemical justification for their spatial distributions.

  13. Conservation of the nucleotide excision repair pathway: characterization of hydra Xeroderma Pigmentosum group F homolog.

    Directory of Open Access Journals (Sweden)

    Apurva Barve

    Full Text Available Hydra, one of the earliest metazoans with tissue grade organization and nervous system, is an animal with a remarkable regeneration capacity and shows no signs of organismal aging. We have for the first time identified genes of the nucleotide excision repair (NER pathway from hydra. Here we report cloning and characterization of hydra homolog of xeroderma pigmentosum group F (XPF gene that encodes a structure-specific 5' endonuclease which is a crucial component of NER. In silico analysis shows that hydra XPF amino acid sequence is very similar to its counterparts from other animals, especially vertebrates, and shows all features essential for its function. By in situ hybridization, we show that hydra XPF is expressed prominently in the multipotent stem cell niche in the central region of the body column. Ectoderm of the diploblastic hydra was shown to express higher levels of XPF as compared to the endoderm by semi-quantitative RT-PCR. Semi-quantitative RT-PCR analysis also demonstrated that interstitial cells, a multipotent and rapidly cycling stem cell lineage of hydra, express higher levels of XPF mRNA than other cell types. Our data show that XPF and by extension, the NER pathway is highly conserved during evolution. The prominent expression of an NER gene in interstitial cells may have implications for the lack of senescence in hydra.

  14. Substance P-like immunoreactivity in the nervous system of hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Balfe, A; Emson, P C

    1981-01-01

    Using immunocytochemistry we find substance P-like material in nerve cells of hydra. These nerve cells are situated in the ectoderm of the basal disk and tentacles. Radioimmunoassay of hydra extracts gives dilution curves parallel to that of synthetic substance P, from which it can be calculated ...

  15. A peptide-gated ion channel from the freshwater polyp Hydra

    DEFF Research Database (Denmark)

    Golubovic, Andjelko; Kuhn, Anne; Williamson, Michael;

    2007-01-01

    regarded as a curiosity, and it was not known whether peptide-gated ionotropic receptors are also present in other animal groups. Nervous systems first evolved in cnidarians, which extensively use neuropeptides. Here we report cloning from the freshwater cnidarian Hydra of a novel ion channel (Hydra sodium...

  16. 骨龄评价方法TW3-RUS、TW3-C carpal、RUS-CHN对比及可重复性分析%Comparing and Analysizing the Repeatability of Assessing Skeletal Age by TW3-RUS,TW3-C carpal and RUS-CHN

    Institute of Scientific and Technical Information of China (English)

    冯红梅; 洪居陆; 何耀强; 杨冠英; 朱彬; 高明勇; 包相华

    2015-01-01

    目的:探讨TW3-RUS、TW3-C carpal、RUS-CHN三种骨龄评价方法的差异性及可重复性.材料与方法:应用TW3-RUS、TW3-C carpal、RUS-CHN三种方法,由2名有骨龄评价培训经历的医师,阅读时间年龄为12岁的正常男性儿童的手腕部X线平片,独立盲法进行骨龄评价.结果:2名医师的骨龄评价结果差别无统计学差异(P>0.05);3种方法对骨龄评价结果的差别有统计学意义(P<0.05);2人组内3种方法两两比较,TW3-Ccarpal与TW3-RUS及RUS-CHN骨龄评价结果的差别有统计学意义(P<0.05),TW3-RUS与RUS-CHN骨龄评价结果的差别无统计学意义(P>0.05).结论:2名医师应用3种方法对12岁男童骨龄评价结果的可重复性高.对12岁男童骨龄评价,TW3-RUS与RUS-CHN法无明显差别,TW3-C carpal与TW3-RUS及RUS-CHN差别较大,推测TW3-C carpal可能不适合12岁男童骨龄评价.

  17. Revisiting the age, evolutionary history and species level diversity of the genus Hydra (Cnidaria: Hydrozoa).

    Science.gov (United States)

    Schwentner, Martin; Bosch, Thomas C G

    2015-10-01

    The genus Hydra has long served as a model system in comparative immunology, developmental and evolutionary biology. Despite its relevance for fundamental research, Hydra's evolutionary origins and species level diversity are not well understood. Detailed previous studies using molecular techniques identified several clades within Hydra, but how these are related to described species remained largely an open question. In the present study, we compiled all published sequence data for three mitochondrial and nuclear genes (COI, 16S and ITS), complemented these with some new sequence data and delimited main genetic lineages (=hypothetical species) objectively by employing two DNA barcoding approaches. Conclusions on the species status of these main lineages were based on inferences of reproductive isolation. Relevant divergence times within Hydra were estimated based on relaxed molecular clock analyses with four genes (COI, 16S, EF1α and 28S) and four cnidarians fossil calibration points All in all, 28 main lineages could be delimited, many more than anticipated from earlier studies. Because allopatric distributions were common, inferences of reproductive isolation often remained ambiguous but reproductive isolation was rarely refuted. Our results support three major conclusions which are central for Hydra research: (1) species level diversity was underestimated by molecular studies; (2) species affiliations of several crucial 'workhorses' of Hydra evolutionary research were wrong and (3) crown group Hydra originated ∼200mya. Our results demonstrate that the taxonomy of Hydra requires a thorough revision and that evolutionary studies need to take this into account when interspecific comparisons are made. Hydra originated on Pangea. Three of four extant groups evolved ∼70mya ago, possibly on the northern landmass of Laurasia. Consequently, Hydra's cosmopolitan distribution is the result of transcontinental and transoceanic dispersal. Copyright © 2015 Elsevier Inc

  18. 76 FR 1149 - T.W. Phillips Pipeline Corp.; Notice of Filing

    Science.gov (United States)

    2011-01-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission T.W. Phillips Pipeline Corp.; Notice of Filing December 30, 2010. Take notice that on December 17, 2010, T.W. Phillips Pipeline Corp. submitted a request for a waiver of...

  19. TW Hya: Spectral Variability, X-Rays, and Accretion Diagnostics

    CERN Document Server

    Dupree, A K; Cranmer, S R; Luna, G J M; Schneider, E E; Bessell, M S; Bonanos, A; Crause, L A; Lawson, W A; Mallik, S V; Schuler, S C

    2012-01-01

    The nearest accreting T Tauri star, TW Hya was observed with spectroscopic and photometric measurements simultaneous with a long se gmented exposure using the CHANDRA satellite. Contemporaneous optical photometry from WASP-S indicates a 4.74 day period was present during this time. Absence of a similar periodicity in the H-alpha flux and the total X-ray flux points to a different source of photometric variations. The H-alpha emission line appears intrinsically broad and symmetric, and both the profile and its variability suggest an origin in the post-shock cooling region. An accretion event, signaled by soft X-rays, is traced spectroscopically for the first time through the optical emission line profiles. After the accretion event, downflowing turbulent material observed in the H-alpha and H-beta lines is followed by He I (5876A) broadening. Optical veiling increases with a delay of about 2 hours after the X-ray accretion event. The response of the stellar coronal emission to an increase in the veiling follow...

  20. M Stars in the TW Hya Association: Stellar X-rays and Disk Dissipation

    CERN Document Server

    Kastner, Joel H; Punzi, Kristina; Stelzer, Beate; Gorti, Uma; Pascucci, Ilaria; Argiroffi, Costanza

    2016-01-01

    To investigate the potential connection between the intense X-ray emission from young, low-mass stars and the lifetimes of their circumstellar, planet-forming disks, we have compiled the X-ray luminosities ($L_X$) of M stars in the $\\sim$8 Myr-old TW Hya Association (TWA) for which X-ray data are presently available. Our investigation includes analysis of archival Chandra data for the TWA binary systems TWA 8, 9, and 13. Although our study suffers from poor statistics for stars later than M3, we find a trend of decreasing $L_X/L_{bol}$ with decreasing $T_{eff}$ for TWA M stars wherein the earliest-type (M0--M2) stars cluster near $\\log{(L_X/L_{bol})} \\approx -3.0$ and then $\\log{(L_X/L_{bol})}$ decreases, and its distribution broadens, for types M4 and later. The fraction of TWA stars that display evidence for residual primordial disk material also sharply increases in this same (mid-M) spectral type regime. This apparent anticorrelation between the relative X-ray luminosities of low-mass TWA stars and the lo...

  1. Constraining Accretion Signatures of Exoplanets in the TW Hya Transitional Disk

    Science.gov (United States)

    Uyama, Taichi; Tanigawa, Takayuki; Hashimoto, Jun; Tamura, Motohide; Aoyama, Yuhiko; Brandt, Timothy D.; Ishizuka, Masato

    2017-09-01

    We present a near-infrared direct imaging search for accretion signatures of possible protoplanets around the young stellar object (YSO) TW Hya, a multi-ring disk exhibiting evidence of planet formation. The Paβ line (1.282 μm) is an indication of accretion onto a protoplanet, and its intensity is much higher than that of blackbody radiation from the protoplanet. We focused on the Paβ line and performed Keck/OSIRIS spectroscopic observations. Although spectral differential imaging (SDI) reduction detected no accretion signatures, the results of the present study allowed us to set 5σ detection limits for Paβ emission of 5.8 × 10-18 and 1.5 × 10-18 erg-1 s-1 cm-2 at 0.″4 and 1.″6, respectively. We considered the mass of potential planets using theoretical simulations of circumplanetary disks and hydrogen emission. The resulting masses were 1.45 ± 0.04 M J and {2.29}-0.04+0.03 {M}{{J}} at 25 and 95 au, respectively, which agree with the detection limits obtained from previous broadband imaging. The detection limits should allow for the identification of protoplanets as small as ˜1 M J, which may assist in direct imaging searches around faint YSOs for which extreme adaptive optics instruments are unavailable.

  2. 水螅的替代食物筛选%Selection of substitute food for hydra

    Institute of Scientific and Technical Information of China (English)

    方小龙; 董卫兵; 喻飞; 陈百香; 丁冉; 胡好远

    2011-01-01

    Food is always scarce when hydra was cultured. In this article , in order to obtain the substituting food for hydra, the feeding behaviors of hydra were compared. The results showed that hydra could catch meats of earthworm, shrimp, fish, chicken, beef and pork. There was no significant difference in the frequency when hydra caught those foods. But the eating frequencies of hydra to those foods were significantly different. Hydra prefers shrimp meat. When the food is scare during culture , the shrimp meat might be selected as a substituting food.%在水螅的培养中,常出现食物缺乏.为了获得替代食物,比较水螅对一些常见肉类的捕食行为.结果表明,水螅对蚯蚓肉、虾肉、鱼肉、鸡肉、牛肉和猪肉均能捕捉,对各食物的捕捉比例无显著差异;但水螅对食物的摄食比例在食物类型间存在显著差异,对虾肉较为偏好.可选择虾肉作为培养时的替代食物.

  3. Ultraviolet irradiation initiates ectopic foot formation in regenerating hydra and promotes budding

    Indian Academy of Sciences (India)

    Saroj S Ghaskadbi; Leena Shetye; Shashi Chiplonkar; Surendra Ghaskadbi

    2005-03-01

    We have studied the effects of ultraviolet-C (UVC) and Ultraviolet-B (UVB) on growth and pattern formation in Pelmatohydra oligactis. UVC brings about a significant increase in budding in intact hydra while UVB does not exhibit such an effect. Excessive budding could be a response for survival at wavelengths that damage biological tissues. If the head or base piece of a bisected hydra is irradiated and recombined with the unirradiated missing part, regeneration proceeds normally indicating that exposure of a body part with either an intact head or foot to UVC does not influence pattern formation. Most significantly, in the middle piece, but not in the head or the base piece of a trisected hydra, UVC leads to initiation of ectopic feet formation in almost one third of the cases. Thus, UV irradiation interferes with pattern formation in regenerating hydra, possibly by changing positional values, and promotes budding in intact hydra. This is the first report on induction of ectopic feet formation by UV in regenerating hydra and opens up the possibility of using UV irradiation as a tool to understand pattern formation in the enigmatic hydra.

  4. The Hydra FGFR, Kringelchen, partially replaces the Drosophila Heartless FGFR.

    Science.gov (United States)

    Rudolf, Anja; Hübinger, Christine; Hüsken, Katrin; Vogt, Angelika; Rebscher, Nicole; Onel, Susanne-Filiz; Renkawitz-Pohl, Renate; Hassel, Monika

    2013-05-01

    Fibroblast growth factor receptors (FGFR) are highly conserved receptor tyrosine kinases, and evolved early in metazoan evolution. In order to investigate their functional conservation, we asked whether the Kringelchen FGFR in the freshwater polyp Hydra vulgaris, is able to functionally replace FGFR in fly embryos. In Drosophila, two endogenous FGFR, Breathless (Btl) and Heartless (Htl), ensure formation of the tracheal system and mesodermal cell migration as well as formation of the heart. Using UAS-kringelchen-5xmyc transgenic flies and targeted expression, we show that Kringelchen is integrated correctly into the cell membrane of mesodermal and tracheal cells in Drosophila. Nevertheless, Kringelchen expression driven in tracheal cells failed to rescue the btl (LG19) mutant. The Hydra FGFR was able to substitute for Heartless in the htl (AB42) null mutant; however, this occurred only during early mesodermal cell migration. Our data provide evidence for functional conservation of this early-diverged FGFR across these distantly related phyla, but also selectivity for the Htl FGFR in the Drosophila system.

  5. Floating attenuator wave energy device: Wavegen HYDRA project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This report describes research funded by the Department of Trade and Industry (DTI) into the feasibility of developing and constructing a floating attenuator wave energy device known as HYDRA following initial studies by Wavegen. HYDRA is a floating externally tensioned articulated raft wave energy generator based on work by Professor FJM Farley and colleagues during the 1980s. The project's first four work tasks confirmed the theoretical potential of the device but also highlighted significant practical problems in translating that potential into a viable design. It was therefore decided not to proceed further, i.e. not to construct and test a prototype device. The report provides a general description of the device and describes the results of the initial analysis and the first series of model tests. It then discusses device design and component testing and explains the methodology for determining device performance at a particular site and mathematical modelling of a one-third scale device. To help future research and development programmes, the report emphasises the generic problems associated with the development of wave devices.

  6. The 2006-2007 Observing Campaign On VX Hydrae

    Science.gov (United States)

    Templeton, Matthew R.; Samolyk, G.; Dvorak, S.; Poklar, R.; Butterworth, N.; Gerner, H. S.

    2009-12-01

    We present the results of the 2006-2007 observing campaign on the double-mode delta Scuti star VX Hydrae. Nearly 8800 V-band CCD observations were obtained during the two observing seasons. Although the data were taken with small telescopes (0.3-m or less, using consumer-grade CCD cameras), the data quality is very high, enabling the detection of variability at the millimagnitude level at some frequencies. Analysis of the data yields only two primary pulsation frequencies: f(0) = 4.4765 c/d, and f(1) = 5.7899 c/d. The two modes have comparable amplitude, although the amplitude of f(1) appears to have increased slightly from 2006 to 2007 by 0.01 mag. Only two pulsation modes are detected, but at least 18 additional linear combination frequencies are also clearly detected, some having amplitudes as low as 1 mmag, resulting in an incredibly rich Fourier spectrum. We discuss the evidence for amplitude variation in VX Hydrae, along with prospects for future study of this and other similar delta Scuti stars by AAVSO observers.

  7. Biometric and statistical investigations on the cnidoma of the genus Hydra (Cnidaria, Hydrozoa

    Directory of Open Access Journals (Sweden)

    Maria I. Deserti

    2012-09-01

    Full Text Available This paper deals about the nematocysts like a source of biometric information for comparison between the species Hydra vulgaris Pallas, 1766, Hydra vulgaris pedunculata Deserti et al., 2011 and Hydra pseudoligactis (Hyman, 1931. This biometric tool lets us carry out statistical comparisons and adding these results to the identification of specimens from different classificatory groups. In this particular study, we obtained significant differences between species, individuals of each species and nematocysts type when compared the biometry of its nematocysts. Another result was the variation in of particular nematocysts, like atrichous isorhiza and holotrichous isorhiza for the species H. vulgaris in relation to the column size.

  8. A nearby young M dwarf with a wide, possibly planetary-mass companion

    Science.gov (United States)

    Deacon, N. R.; Schlieder, J. E.; Murphy, S. J.

    2016-04-01

    We present the identification of two previously known young objects in the solar neighbourhood as a likely very wide binary. TYC 9486-927-1, an active, rapidly rotating early-M dwarf, and 2MASS J21265040-8140293, a low-gravity L3 dwarf previously identified as candidate members of the ˜45 Myr old Tucana-Horologium association (TucHor). An updated proper motion measurement of the L3 secondary, and a detailed analysis of the pair's kinematics in the context of known nearby, young stars, reveals that they share common proper motion and are likely bound. New observations and analyses reveal the primary exhibits Li 6708 Å absorption consistent with M dwarfs younger than TucHor but older than the ˜10 Myr TW Hydra association yielding an age range of 10-45 Myr. A revised kinematic analysis suggests the space motions and positions of the pair are closer to, but not entirely in agreement with, the ˜24 Myr old β Pictoris moving group. This revised 10-45 Myr age range yields a mass range of 11.6-15 MJ for the secondary. It is thus likely 2MASS J2126-8140 is the widest orbit planetary-mass object known (>4500 au) and its estimated mass, age, spectral type, and Teff are similar to the well-studied planet β Pictoris b. Because of their extreme separation and youth, this low-mass pair provide an interesting case study for very wide binary formation and evolution.

  9. Modifications to hydra-gym equipment provide for clinically useful strength measurements.

    Science.gov (United States)

    Tremblay, M S; Lovely, D F; McInnis, M D; Sexsmith, J R

    1994-04-01

    Modifications were made to the Series III-311 Omnikinetic Hydra-Gym apparatus (Hydra-Fitness Industries Inc., Belton, TX) in an effort to provide relatively inexpensive yet clinically useful isokinetic strength measurements. Signal transmission and processing functions were installed to calculate relevant strength characteristics for knee extension/flexion motions. Results from the modified Hydra-Gym were compared with matched procedures on the Kin-Com (model 500-10, Chattecx Corporation, Chattanooga, TN). Subjects (N = 10) performed three maximal concentric right knee extension/flexion cycles at different resistance settings (2, 4, and 6) on the Hydra-Gym and the corresponding angular velocities on the Kin-Com (190, 125, and 40 degrees/sec, respectively). Each subject completed eight testing sessions, four on each dynamometer. A five-way analysis of variance on the peak torque data revealed no significant difference between dynamometers; however, there was a significant interaction between dynamometer and extension/flexion measurements. The variance in angle of peak torque data was significantly different between dynamometers, with Hydra-Gym showing superior reproducibility (p Gym because the interaction noticed between dynamometer and extension/flexion may exaggerate muscle imbalances. In summary, modifications to the Hydra-Gym appear to provide clinicians with a reliable and clinically useful strength testing alternative.

  10. Immunochemical Localization of GABAA Receptor Subunits in the Freshwater Polyp Hydra vulgaris (Cnidaria, Hydrozoa).

    Science.gov (United States)

    Concas, A; Imperatore, R; Santoru, F; Locci, A; Porcu, P; Cristino, L; Pierobon, P

    2016-11-01

    γ-aminobutyric acid (GABA) receptors, responding to GABA positive allosteric modulators, are present in the freshwater polyp Hydra vulgaris (Cnidaria, Hydrozoa), one of the most primitive metazoans to develop a nervous system. We examined the occurrence and distribution of GABAA receptor subunits in Hydra tissues by western blot and immunohistochemistry. Antibodies against different GABAA receptor subunits were used in Hydra membrane preparations. Unique protein bands, inhibited by the specific peptide, appeared at 35, 60, ∼50 and ∼52 kDa in membranes incubated with α3, β1, γ3 or δ antibodies, respectively. Immunohistochemical screening of whole mount Hydra preparations revealed diffuse immunoreactivity to α3, β1 or γ3 antibodies in tentacles, hypostome, and upper part of the gastric region; immunoreactive fibers were also present in the lower peduncle. By contrast, δ antibodies revealed a strong labeling in the lower gastric region and peduncle, as well as in tentacles. Double labeling showed colocalization of α3/β1, α3/γ3 and α3/δ immunoreactivity in granules or cells in tentacles and gastric region. In the peduncle, colocalization of both α3/β1 and α3/γ3 immunoreactivity was found in fibers running horizontally above the foot. These data indicate that specific GABAA receptor subunits are present and differentially distributed in Hydra body regions. Subunit colocalization suggests that Hydra GABA receptors are heterologous multimers, possibly sub-serving different physiological activities.

  11. Evidence That Hydra I is a Tidally Disrupting Milky Way Dwarf Galaxy

    CERN Document Server

    Hargis, Jonathan R; Willman, B; Caldwell, N; Walker, M G; Strader, J; Sand, D J; Grillmair, C J; Yoon, J H

    2015-01-01

    The Eastern Banded Structure (EBS) and Hydra~I halo overdensity are very nearby (d $\\sim$ 10 kpc) objects discovered in SDSS data. Previous studies of the region have shown that EBS and Hydra I are spatially coincident, cold structures at the same distance, suggesting that Hydra I may be the EBS's progenitor. We combine new wide-field DECam imaging and MMT/Hectochelle spectroscopic observations of Hydra I with SDSS archival spectroscopic observations to quantify Hydra I's present-day chemodynamical properties, and to infer whether it originated as a star cluster or dwarf galaxy. While previous work using shallow SDSS imaging assumed a standard old, metal-poor stellar population, our deeper DECam imaging reveals that Hydra~I has a thin, well-defined main sequence turnoff of intermediate age ($\\sim 5-6$ Gyr) and metallicity ([Fe/H] = $-0.9$ dex). We measure statistically significant spreads in both the iron and alpha-element abundances of $\\sigma_{[Fe/H]} = 0.13 \\pm 0.02$ dex and $\\sigma_{[\\alpha/{\\rm Fe}]} = 0...

  12. Environmental challenges improve resource utilization for asexual reproduction and maintenance in hydra.

    Science.gov (United States)

    Schaible, Ralf; Ringelhan, Felix; Kramer, Boris H; Miethe, Tanja

    2011-10-01

    Variation in life history can reflect genetic differences, and may be caused by environmental effects on phenotypes. Understanding how these two sources of life history variation interact to express an optimal allocation of resources in a changing environment is central to life history theory. This study addresses variation in the allocation of resources to asexual reproduction and to maintenance of Hydra magnipapillata in relation to differences in temperature and food availability. Hydra is a non-senescent, persistent species with primarily clonal reproduction. We recorded changes in budding rate and mean survival under starvation, which indicate changes in the allocation of resources to asexual reproduction and maintenance. In constant conditions we observed a clear trade-off between asexual reproduction and maintenance, where budding increased linearly with food intake while starvation survival stayed rather constant. In contrast, an environment with fluctuations in temperature or food availability promotes maintenance and increases the survival chances of hydra under starvation. Surprisingly, asexual reproduction also tends to be positively affected by fluctuating environmental conditions, which suggests that in this case there is no clear trade-off between asexual reproduction and maintenance in hydra. Environmental stresses have a beneficial impact on the fitness-related phenotypical traits of the basal metazoan hydra. The results indicate that, if the stress occurs in hormetic doses, variable stressful and fluctuating environments can be salutary for hydra. A closer examination of this dynamic can therefore enable us to develop a deeper understanding of the evolution of aging and longevity.

  13. Hydra: a service oriented architecture for scientific simulation integration

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell [Los Alamos National Laboratory; Djidjev, Tatiana [Los Alamos National Laboratory; Hayes, Birch P [Los Alamos National Laboratory; Holland, Joe V [Los Alamos National Laboratory; Khalsa, Hari S [Los Alamos National Laboratory; Linger, Steve P [Los Alamos National Laboratory; Mathis, Mark M [Los Alamos National Laboratory; Mniszewski, Sue M [Los Alamos National Laboratory; Bush, Brian [NATIONAL RENEWABLE ENERGY LAB

    2008-01-01

    One of the current major challenges in scientific modeling and simulation, in particular in the infrastructure-analysis community, is the development of techniques for efficiently and automatically coupling disparate tools that exist in separate locations on different platforms, implemented in a variety of languages and designed to be standalone. Recent advances in web-based platforms for integrating systems such as SOA provide an opportunity to address these challenges in a systematic fashion. This paper describes Hydra, an integrating architecture for infrastructure modeling and simulation that defines geography-based schemas that, when used to wrap existing tools as web services, allow for seamless plug-and-play composability. Existing users of these tools can enhance the value of their analysis by assessing how the simulations of one tool impact the behavior of another tool and can automate existing ad hoc processes and work flows for integrating tools together.

  14. Effects of water hardness and alkalinity on the toxicity of uranium to a tropical freshwater hydra (Hydra viridissima).

    Science.gov (United States)

    Riethmuller, N; Markich, S J; Van Dam, R A; Parry, D

    2001-01-01

    In tropical Australian freshwaters, uranium (U) is of potential ecotoxicological concern, largely as a consequence of mining activities. Although the toxicity of uranium to Australian freshwater biota is comprehensive, by world standards, few data are available on the effects of physicochemical variables, such as hardness, alkalinity, pH and organic matter, on uranium speciation and bioavailability. This study determined the individual effects of water hardness (6.6, 165 and 330 mg l(-1) as CaCO3) and alkalinity (4.0 and 102 mg l(-1) as CaCO3), at a constant pH (6.0), on the toxicity (96 h population growth) of uranium to Hydra viridissima (green hydra). A 50-fold increase in hardness (Ca and Mg concentration) resulted in a 92% (two-fold) decrease in the toxicity of uranium to H. viridissima [i.e. an increase in the EC50 value and 95% confidence interval from 114 (107-121) to 219 (192-246) µg l(-1)]. Conversely, at a constant hardness (165 mg l-1 as CaCO3), the toxicity of uranium to H. viridissima was not significantly (P > 0.05) affected by a 25-fold increase in alkalinity (carbonate concentration) [i.e. EC50 values of 177 (166-188) and 171 (150-192) µg l(-1) at 4.0 and 102 mg l(-1) as CaCO3, respectively]. A knowledge of the relationship between water chemistry variables, including hardness and alkalinity, and uranium toxicity is useful for predicting the potential ecological detriment in aquatic systems, and can be used to relax national water quality guidelines on a site-specific basis.

  15. RF Design of the TW Buncher for the CLIC Drive Beam Injector

    CERN Document Server

    Shaker, H

    2015-01-01

    The CLIC is based on the two beams concept that one beam (drive beam) produces the required RF power to accelerate another beam (main beam). The drive beam is produced and accelerated up to 50MeV inside the CLIC drive beam injector. The drive beam injector main components are a thermionic electron gun, three sub harmonic bunchers, a pre-buncher, a TW buncher, 13 accelerating structures and one magnetic chicane. This document is the first report of the RF structure design of the TW buncher. This design is based on the beam dynamic design done by Shahin Sanaye Hajari due to requirements mentioned in CLIC CDR. A disk-loaded tapered structure is chosen for the TW buncher. The axial electric field increases strongly based on the beam dynamic requirements. This report includes the design of the power couplers. The fundamental mode beam loading and higher order modes effect were preliminary studied.

  16. EPSON dorimio EMP-TW10H投影机

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    爱普生去年用dorimio品牌第一次发售了dorimio EMP-TW10投影机。具有普及性价格、真实感动的高画质和动人的大画面.加上简单到谁都能使用的理念.因此得到市场的好评。这次爱普生推出了EMP-TW10的升级版EMP-TW10H.在万元级的投影市场上又增加了一个很有竞争力的选手。

  17. RF Design of the TW Buncher for the CLIC Drive Beam Injector (2nd report)

    CERN Document Server

    Shaker, Hamed

    2016-01-01

    CLIC is based on the two beams concept that one beam (drive beam) produces the required RF power to accelerate another beam (main beam). The drive beam is produced and accelerated up to 50MeV inside the CLIC drive beam injector. The drive beam injector main components are a thermionic electron gun, three sub-harmonic bunchers, a pre-buncher, a TW buncher, 13 accelerating structures and one magnetic chicane. This document is the second report of the RF structure design of the TW buncher. This design is based on the beam dynamic design done by Shahin Sanaye Hajari due to requirements mentioned in CLIC CDR. A disk-loaded tapered structure is chosen for the TW buncher. The axial electric field increases strongly based on the beam dynamic requirements. This second report includes the study of HOM effects, retuning the cells, study of dimensional tolerances and the heat dissipation on the surface.

  18. Hohlraum energetics scaling to 520 TW on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Kline, J. L.; Grim, G.; Kyrala, G. A.; Batha, S. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Callahan, D. A.; Glenzer, S. H.; Meezan, N. B.; Moody, J. D.; Hinkel, D. E.; Jones, O. S.; MacKinnon, A. J.; Bennedetti, R.; Berger, R. L.; Bradley, D.; Dewald, E. L.; Bass, I.; Bennett, C.; Bowers, M.; Brunton, G.; Bude, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2013-05-15

    Indirect drive experiments have now been carried out with laser powers and energies up to 520 TW and 1.9 MJ. These experiments show that the energy coupling to the target is nearly constant at 84% ± 3% over a wide range of laser parameters from 350 to 520 TW and 1.2 to 1.9 MJ. Experiments at 520 TW with depleted uranium hohlraums achieve radiation temperatures of ∼330 ± 4 eV, enough to drive capsules 20 μm thicker than the ignition point design to velocities near the ignition goal of 370 km/s. A series of three symcap implosion experiments with nearly identical target, laser, and diagnostics configurations show the symmetry and drive are reproducible at the level of ±8.5% absolute and ±2% relative, respectively.

  19. Three homologous subunits form a high affinity peptide-gated ion channel in Hydra

    DEFF Research Database (Denmark)

    Dürrnagel, Stefan; Kuhn, Anne; Tsiairis, Charisios D

    2010-01-01

    properties, like a low Na(+) selectivity and a low amiloride affinity, that are different from other channels of the DEG/ENaC gene family, suggesting that a component of the native Hydra channel might still be lacking. Here, we report the cloning of a new ion channel subunit from Hydra, HyNaC5. The new......Recently, three ion channel subunits of the degenerin (DEG)/epithelial Na(+) channel (ENaC) gene family have been cloned from the freshwater polyp Hydra magnipapillata, the Hydra Na(+) channels (HyNaCs) 2-4. Two of them, HyNaC2 and HyNaC3, co-assemble to form an ion channel that is gated...... by the neuropeptides Hydra-RFamides I and II. The HyNaC2/3 channel is so far the only cloned ionotropic receptor from cnidarians and, together with the related ionotropic receptor FMRFamide-activated Na(+) channel (FaNaC) from snails, the only known peptide-gated ionotropic receptor. The HyNaC2/3 channel has pore...

  20. Development and population growth of Hydra viridissima Pallas, 1766 (Cnidaria, Hydrozoa in the laboratory

    Directory of Open Access Journals (Sweden)

    FC. Massaro

    Full Text Available Hydras, the most representative freshwater Cnidaria, are of common occurrence in bodies of water in every continent except Antarctica. This study was planned with the aim of maintaining a population of Hydra viridissima in laboratory culture to enable the determination of the individual and population growth-rates of this species, as well as its population doubling time and generation time, with a view to employing these common animals as test-organisms in ecotoxicological assays. The organisms were maintained in reconstituted water at 20 ± 2 °C, illuminated at 800 lux with a photoperiod of 12 hours light: 12 hours dark, and were fed on neonates of the cladoceran Ceriodaphnia silvestrii (3 or 4 neonates per hydra, 3 times a week. The individual growth-rate (k of the species was 0.43, the maximum length of the column 2.53 mm and the generation time 6.6 ± 1.5 days on average. The hydra population showed an intrinsic growth-rate (r of 0.0468, according to the fitted curve, and a doubling time of 14.8 ± 2.63 days. Hydra viridissima is easy to grow in the laboratory and performs well in the conditions used in this study. It is thus a promising candidate test-organism for ecotoxicological studies.

  1. Development and population growth of Hydra viridissima Pallas, 1766 (Cnidaria, Hydrozoa) in the laboratory.

    Science.gov (United States)

    Massaro, F C; Rocha, O

    2008-05-01

    Hydras, the most representative freshwater Cnidaria, are of common occurrence in bodies of water in every continent except Antarctica. This study was planned with the aim of maintaining a population of Hydra viridissima in laboratory culture to enable the determination of the individual and population growth-rates of this species, as well as its population doubling time and generation time, with a view to employing these common animals as test-organisms in ecotoxicological assays. The organisms were maintained in reconstituted water at 20 +/- 2 degrees C, illuminated at 800 lux with a photoperiod of 12 hours light: 12 hours dark, and were fed on neonates of the cladoceran Ceriodaphnia silvestrii (3 or 4 neonates per hydra, 3 times a week). The individual growth-rate (k) of the species was 0.43, the maximum length of the column 2.53 mm and the generation time 6.6 +/- 1.5 days on average. The hydra population showed an intrinsic growth-rate (r) of 0.0468, according to the fitted curve, and a doubling time of 14.8 +/- 2.63 days. Hydra viridissima is easy to grow in the laboratory and performs well in the conditions used in this study. It is thus a promising candidate test-organism for ecotoxicological studies.

  2. The phosphatidylserine receptor from Hydra is a nuclear protein with potential Fe(II dependent oxygenase activity

    Directory of Open Access Journals (Sweden)

    Stiening Beate

    2004-06-01

    Full Text Available Abstract Background Apoptotic cell death plays an essential part in embryogenesis, development and maintenance of tissue homeostasis in metazoan animals. The culmination of apoptosis in vivo is the phagocytosis of cellular corpses. One morphological characteristic of cells undergoing apoptosis is loss of plasma membrane phospholipid asymmetry and exposure of phosphatidylserine on the outer leaflet. Surface exposure of phosphatidylserine is recognised by a specific receptor (phosphatidylserine receptor, PSR and is required for phagocytosis of apoptotic cells by macrophages and fibroblasts. Results We have cloned the PSR receptor from Hydra in order to investigate its function in this early metazoan. Bioinformatic analysis of the Hydra PSR protein structure revealed the presence of three nuclear localisation signals, an AT-hook like DNA binding motif and a putative 2-oxoglutarate (2OG-and Fe(II-dependent oxygenase activity. All of these features are conserved from human PSR to Hydra PSR. Expression of GFP tagged Hydra PSR in hydra cells revealed clear nuclear localisation. Deletion of one of the three NLS sequences strongly diminished nuclear localisation of the protein. Membrane localisation was never detected. Conclusions Our results suggest that Hydra PSR is a nuclear 2-oxoglutarate (2OG-and Fe(II-dependent oxygenase. This is in contrast with the proposed function of Hydra PSR as a cell surface receptor involved in the recognition of apoptotic cells displaying phosphatidylserine on their surface. The conservation of the protein from Hydra to human infers that our results also apply to PSR from higher animals.

  3. Time-Variable Accretion in the TW Hya Star/Disk System

    CERN Document Server

    Eisner, J A; Najita, J R; McCarthy, D; Kulesa, C; Swift, B J; Teske, J

    2010-01-01

    We present two epochs of observations of TW Hya from the high-dispersion near-IR spectrograph ARIES at the MMT. We detect strong emission from the Brackett gamma transition of hydrogen, indicating an accretion rate substantially larger than previously estimated using hydrogen line emission. The Brackett gamma line-strength varies across our two observed epochs. We also measure circumstellar-to-stellar flux ratios (i.e., veilings) that appear close to zero in both epochs. These findings suggest that TW Hya experiences episodes of enhanced accretion while the inner disk remains largely devoid of dust. We discuss several physical mechanisms that may explain these observations.

  4. Hydra-TH User's Manual, Version: LA-CC-11120, Dated: December 1, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Christon, Mark A. [Los Alamos National Laboratory; Bakosi, Jozsef [Los Alamos National Laboratory; Lowrie, Robert B. [Los Alamos National Laboratory

    2012-07-19

    Hydra-TH is a hybrid finite-element/finite-volume code built using the Hydra toolkit specifically to attack a broad class of incompressible, viscous fluid dynamics problems prevalent in the thermalhydraulics community. The purpose for this manual is provide sufficient information for an experience analyst to use Hydra-TH in an effective way. The Hydra-TH User's Manual present a brief overview of capabilities and visualization interfaces. The execution and restart models are described before turning to the detailed description of keyword input. Finally, a series of example problems are presented with sufficient data to permit the user to verify the local installation of Hydra-TH, and to permit a convenient starting point for more detailed and complex analyses.

  5. The cluster-scale AGN outburst in Hydra A

    CERN Document Server

    Nulsen, P E J; Wise, M W; David, L P

    2004-01-01

    Deep Chandra observations of the Hydra A Cluster reveal a feature in the X-ray surface brightness that surrounds the 330 MHz radio lobes of the AGN at the cluster center. Surface brightness profiles of this feature and its close association with the radio lobes argue strongly that it is a shock front driven by the expanding radio lobes. The Chandra image also reveals other new structure on smaller scales that is associated with the radio source, including a large cavity and filament. The shock front extends 200 - 300 kpc from the AGN at the cluster center and its strength varies along the front, with Mach numbers in the range ~ 1.2 - 1.4. It is stronger where it is more distant from the cluster center, as expected for a shock driven by expanding radio lobes. Simple modeling gives an age for the shock front ~ 1.4\\times10^8 y and a total energy driving it of ~ 10^{61} erg. The mean mechanical power driving the shock is comparable to quasar luminosities, well in excess of that needed to regulate the cooling core...

  6. Progress and status of cryogenic refrigeration system for project Hydra

    Science.gov (United States)

    Yuan, J.; Catseman, F.; Tilleman, H.; Henderson, N.

    2015-12-01

    In the last two decades, HTS cables have been successfully demonstrated around the world, preparing HTS power cables for a full commercial introduction. Among the demonstration projects, circulating subcooled liquid nitrogen to maintain the HTS cable at operating temperature is a widely adopted approach. In this approach, the cooling systems are absolutely critical to the successful operation of the HTS cables. This paper describes the progress and status of the cryogenic refrigeration system designed and manufactured for project Hydra, which is a project jointly funded by the U.S. Department of Homeland Security Science and Technology Directorate, American Superconductor and Consolidated Edison Company of New York, Inc. American Superconductor is leading the team supported by Con Edison, Ultera, Altran Solutions, and DH Industries. The cable is an inherently fault current limiting HTS cable, approximately 200 m long and designed to carry 96 MVA at a distribution level voltage of 13.8 kV. The cable will be installed and energized near New York City. The refrigeration system was designed and manufactured by DH Industries. This paper provides details on the successful factory acceptance testing completed in November 2014.

  7. Phylogenetic placement of Hydra and relationships within Aplanulata (Cnidaria: Hydrozoa).

    Science.gov (United States)

    Nawrocki, Annalise M; Collins, Allen G; Hirano, Yayoi M; Schuchert, Peter; Cartwright, Paulyn

    2013-04-01

    The model organism Hydra belongs to the hydrozoan clade Aplanulata. Despite being a popular model system for development, little is known about the phylogenetic placement of this taxon or the relationships of its closest relatives. Previous studies have been conflicting regarding sister group relationships and have been unable to resolve deep nodes within the clade. In addition, there are several putative Aplanulata taxa that have never been sampled for molecular data or analyzed using multiple markers. Here, we combine the fast-evolving cytochrome oxidase 1 (CO1) mitochondrial marker with mitochondrial 16S, nuclear small ribosomal subunit (18S, SSU) and large ribosomal subunit (28S, LSU) sequences to examine relationships within the clade Aplanulata. We further discuss the relative contribution of four different molecular markers to resolving phylogenetic relationships within Aplanulata. Lastly, we report morphological synapomorphies for some of the major Aplanulata genera and families, and suggest new taxonomic classifications for two species of Aplanulata, Fukaurahydra anthoformis and Corymorpha intermedia, based on a preponderance of molecular and morphological data that justify the designation of these species to different genera. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Innexin gap junctions in nerve cells coordinate spontaneous contractile behavior in Hydra polyps

    Science.gov (United States)

    Takaku, Yasuharu; Hwang, Jung Shan; Wolf, Alexander; Böttger, Angelika; Shimizu, Hiroshi; David, Charles N.; Gojobori, Takashi

    2014-01-01

    Nerve cells and spontaneous coordinated behavior first appeared near the base of animal evolution in the common ancestor of cnidarians and bilaterians. Experiments on the cnidarian Hydra have demonstrated that nerve cells are essential for this behavior, although nerve cells in Hydra are organized in a diffuse network and do not form ganglia. Here we show that the gap junction protein innexin-2 is expressed in a small group of nerve cells in the lower body column of Hydra and that an anti-innexin-2 antibody binds to gap junctions in the same region. Treatment of live animals with innexin-2 antibody eliminates gap junction staining and reduces spontaneous body column contractions. We conclude that a small subset of nerve cells, connected by gap junctions and capable of synchronous firing, act as a pacemaker to coordinate the contraction of the body column in the absence of ganglia.

  9. Innexin gap junctions in nerve cells coordinate spontaneous contractile behavior in Hydra polyps

    KAUST Repository

    Takaku, Yasuharu

    2014-01-07

    Nerve cells and spontaneous coordinated behavior first appeared near the base of animal evolution in the common ancestor of cnidarians and bilaterians. Experiments on the cnidarian Hydra have demonstrated that nerve cells are essential for this behavior, although nerve cells in Hydra are organized in a diffuse network and do not form ganglia. Here we show that the gap junction protein innexin-2 is expressed in a small group of nerve cells in the lower body column of Hydra and that an anti-innexin-2 antibody binds to gap junctions in the same region. Treatment of live animals with innexin-2 antibody eliminates gap junction staining and reduces spontaneous body column contractions. We conclude that a small subset of nerve cells, connected by gap junctions and capable of synchronous firing, act as a pacemaker to coordinate the contraction of the body column in the absence of ganglia.

  10. The toxicity of copper, cadmium and zinc to four different Hydra (Cnidaria: Hydrozoa).

    Science.gov (United States)

    Karntanut, Wanchamai; Pascoe, David

    2002-06-01

    An acute toxicity study of three metals to Hydra species carried out using two different assessment methods, (i) determination of the LC50 and (ii) measurement of progressive morphological changes, demonstrated that relative toxicity decreased from copper to cadmium with zinc the least toxic for all species. The latter method revealed more details of the effect on Hydra in terms of physical damage to the polyp but both methods indicated that H. viridissima was more sensitive to copper and cadmium than H. vulgaris1 (Zurich strain, male clone), H. vulgaris2 (a dioecious strain reproducing sexually and asexually) and H. oligactis (dioecious, reproducing sexually and asexually). The responses to zinc were similar for all Hydra. The possible role of metabolic interactions between H. viridissima and its symbiotic green algae in contributing to the greater sensitivity of this polyp is discussed.

  11. Nerve ring of the hypostome in hydra. I. Its structure, development, and maintenance

    DEFF Research Database (Denmark)

    Koizumi, O; Itazawa, M; Mizumoto, H

    1992-01-01

    neuronal complex consisting of a thick nerve bundle running circumferentially at the border between the hypostome and tentacle zone. Immunostaining showed that the nerve ring was heterogeneous and contained at least four different subsets of neurons. During head regeneration and budding, the nerve ring......The anatomy and developmental dynamics of the nerve ring in the hypostome of Hydra oligactis were examined immunocytochemically with an antiserum against a neuropeptide and with neuron-specific monoclonal antibodies. The nerve ring is unique in the mesh-like nerve net of hydra. It is a distinct...... appeared only after the nerve net of ganglion and sensory cells had formed. Every epithelial cell is continuously displaced with neurons toward either head or foot in an adult hydra. However, the ectoderm in the immediate vicinity of, and including, the nerve ring constitutes a stationary zone...

  12. The solar neighborhood. XXXIII. Parallax results from the CTIOPI 0.9 m program: trigonometric parallaxes of Nearby low-mass active and young systems

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Adric R.; Cruz, Kelle L. [Department of Physics and Astronomy, Hunter College, The City University of New York, 695 Park Avenue, New York, NY 10065 (United States); Finch, Charlie T. [Astrometry Department, U.S. Naval Observatory, Washington, DC 20392 (United States); Henry, Todd J.; Jao, Wei-Chun; White, Russel J.; Gies, Douglas R.; Dieterich, Sergio B.; Winters, Jennifer G.; Davison, Cassy L. [Department of Physics and Astronomy, Georgia State University, P.O. Box 5060, Atlanta, GA 30302-5060 (United States); Subasavage, John P. [United States Naval Observatory, Flagstaff, AZ 86001 (United States); Malo, Lison [Département de Physique et Observatoire du Mont-Megantic, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7 (Canada); Rodriguez, David R. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Las Condes, Santiago (Chile); Nelan, Edmund P. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Blunt, Sarah C.; Rice, Emily L. [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States); Ianna, Philip A., E-mail: ar494@hunter.cuny.edu [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)

    2014-04-01

    We present basic observational data and association membership analysis for 45 young and active low-mass stellar systems from the ongoing Research Consortium On Nearby Stars photometry and astrometry program at the Cerro Tololo Inter-American Observatory. Most of these systems have saturated X-ray emission (log (L{sub X} /L {sub bol}) > –3.5) based on X-ray fluxes from the ROSAT All-Sky Survey, and many are significantly more luminous than main-sequence stars of comparable color. We present parallaxes and proper motions, Johnson-Kron-Cousins VRI photometry, and multiplicity observations from the CTIOPI program on the CTIO 0.9 m telescope. To this we add low-resolution optical spectroscopy and line measurements from the CTIO 1.5 m telescope, and interferometric binary measurements from the Hubble Space Telescope Fine Guidance Sensors. We also incorporate data from published sources: JHK{sub S} photometry from the Two Micron All Sky Survey point source catalog, X-ray data from the ROSAT All-Sky Survey, and radial velocities from literature sources. Within the sample of 45 systems, we identify 21 candidate low-mass pre-main-sequence members of nearby associations, including members of β Pictoris, TW Hydrae, Argus, AB Doradus, two ambiguous ≈30 Myr old systems, and one object that may be a member of the Ursa Major moving group. Of the 21 candidate young systems, 14 are newly identified as a result of this work, and six of those are within 25 pc of the Sun.

  13. Slow-cycling stem cells in hydra contribute to head regeneration

    Directory of Open Access Journals (Sweden)

    Niraimathi Govindasamy

    2014-11-01

    Full Text Available Adult stem cells face the challenge of maintaining tissue homeostasis by self-renewal while maintaining their proliferation potential over the lifetime of an organism. Continuous proliferation can cause genotoxic/metabolic stress that can compromise the genomic integrity of stem cells. To prevent stem cell exhaustion, highly proliferative adult tissues maintain a pool of quiescent stem cells that divide only in response to injury and thus remain protected from genotoxic stress. Hydra is a remarkable organism with highly proliferative stem cells and ability to regenerate at whole animal level. Intriguingly, hydra does not display consequences of high proliferation, such as senescence or tumour formation. In this study, we investigate if hydra harbours a pool of slow-cycling stem cells that could help prevent undesirable consequences of continuous proliferation. Hydra were pulsed with the thymidine analogue 5-ethynyl-2′-deoxyuridine (EdU and then chased in the absence of EdU to monitor the presence of EdU-retaining cells. A significant number of undifferentiated cells of all three lineages in hydra retained EdU for about 8–10 cell cycles, indicating that these cells did not enter cell cycle. These label-retaining cells were resistant to hydroxyurea treatment and were predominantly in the G2 phase of cell cycle. Most significantly, similar to mammalian quiescent stem cells, these cells rapidly entered cell division during head regeneration. This study shows for the first time that, contrary to current beliefs, cells in hydra display heterogeneity in their cell cycle potential and the slow-cycling cells in this population enter cell cycle during head regeneration. These results suggest an early evolution of slow-cycling stem cells in multicellular animals.

  14. Inotropic response elicited by nematocyst contents of Hydra oligactis (Coelenterata: Hydrozoa).

    Science.gov (United States)

    Lesh-Laurie, G E; DiBlasi, S L; Suchy, P E; Senturia, J B

    1989-01-01

    1. Intact, isolated nematocysts from the non-toxic, freshwater coelenterate Hydra oligactis contain soluble material(s) capable of producing a sustained increase in the rate of developed force in the vertebrate myocardium. 2. The positive inotropic effects of this material(s) appear grossly comparable to those described for Anthopleurin-A (AP-A) and Toxin II (ATX-II) from sea anemones. 3. The effects of the nematocyst material are distinct from those of known vasoactive peptides reported to occur in Hydra.

  15. Simulation studies of laser wakefield acceleration based on typical 100 TW laser facilities

    Institute of Scientific and Technical Information of China (English)

    李大章; 高杰; 朱雄伟; 何安

    2011-01-01

    In this paper, 2-D Particle-In-Cell simulations are made for Laser Wakefield Accelerations (LWFA). As in a real experiment, we perform plasma density scanning for typical 100 TW laser facilities. Several basic laws for self-injected acceleration in a bubb

  16. Evolution of hydra, a recently evolved testis-expressed gene with nine alternative first exons in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Shou-Tao Chen

    2007-07-01

    Full Text Available We describe here the Drosophila gene hydra that appears to have originated de novo in the melanogaster subgroup and subsequently evolved in both structure and expression level in Drosophila melanogaster and its sibling species. D. melanogaster hydra encodes a predicted protein of approximately 300 amino acids with no apparent similarity to any previously known proteins. The syntenic region flanking hydra on both sides is found in both D. ananassae and D. pseudoobscura, but hydra is found only in melanogaster subgroup species, suggesting that it originated less than approximately 13 million y ago. Exon 1 of hydra has undergone recurrent duplications, leading to the formation of nine tandem alternative exon 1s in D. melanogaster. Seven of these alternative exons are flanked on their 3' side by the transposon DINE-1 (Drosophila interspersed element-1. We demonstrate that at least four of the nine duplicated exon 1s can function as alternative transcription start sites. The entire hydra locus has also duplicated in D. simulans and D. sechellia. D. melanogaster hydra is expressed most intensely in the proximal testis, suggesting a role in late-stage spermatogenesis. The coding region of hydra has a relatively high Ka/Ks ratio between species, but the ratio is less than 1 in all comparisons, suggesting that hydra is subject to functional constraint. Analysis of sequence polymorphism and divergence of hydra shows that it has evolved under positive selection in the lineage leading to D. melanogaster. The dramatic structural changes surrounding the first exons do not affect the tissue specificity of gene expression: hydra is expressed predominantly in the testes in D. melanogaster, D. simulans, and D. yakuba. However, we have found that expression level changed dramatically (approximately >20-fold between D. melanogaster and D. simulans. While hydra initially evolved in the absence of nearby transposable element insertions, we suggest that the subsequent

  17. Two-Step Evolution of Endosymbiosis between Hydra and Algae

    KAUST Repository

    Ishikawa, Masakazu

    2016-07-09

    In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor algae remains unknown. The endosymbiotic potential of non-symbiotic strains that can harbor algae may have been acquired before or during divergence of the strains. With the aim of understanding the evolutionary process of endosymbiosis in the H. vulgaris group, we examined the endosymbiotic potential of non-symbiotic strains of the H. vulgaris group by artificially introducing endosymbiotic algae. We found that 12 of the 23 non-symbiotic strains were able to harbor the algae until reaching the grand-offspring through the asexual reproduction by budding. Moreover, a phylogenetic analysis of mitochondrial genome sequences showed that all the strains with endosymbiotic potential grouped into a single cluster (cluster γ). This cluster contained two strains (J7 and J10) that currently harbor algae; however, these strains were not the closest relatives. These results suggest that evolution of endosymbiosis occurred in two steps; first, endosymbiotic potential was gained once in the ancestor of the cluster γ lineage; second, strains J7 and J10 obtained algae independently after the divergence of the strains. By demonstrating the evolution of the endosymbiotic potential in non-symbiotic H. vulgaris group strains, we have clearly distinguished two evolutionary steps. The step-by-step evolutionary process provides significant insight into the evolution of endosymbiosis in cnidarians.

  18. Glutamatergic transmission in hydra: NMDA/D-serine affects the electrical activity of the body and tentacles of Hydra vulgaris (Cnidaria, Hydrozoa).

    Science.gov (United States)

    Kay, J C; Kass-Simon, G

    2009-04-01

    Previous electrophysiological studies on the early-evolved metazoan Hydra vulgaris provided evidence that glutamate, acting through alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate receptors, affects hydra's pacemaker systems; immunocytochemical studies showed that N-methyl-d-aspartate (NMDA) receptors were present in hydra tentacles; behavioral studies demonstrated that NMDA/d-serine affected mouth opening induced by reduced glutathione, and with AMPA/kainate, discharge of nematocysts. In this study, extracellular recordings were made from the tentacle and peduncle of hydra during bath application of NMDA and d-serine (both at 1 x 10(-5) mol l(-1) to 1 x 10(-9) mol l(-1)) in the presence of 1 x 10(-7) mol l(-1) AMPA or kainate. NMDA/d-serine produced a significant increase in tentacle activity, increasing the rate of tentacle pacemaker pulses (TPs) at 1 x 10(-7) mol l(-1), and small, behaviorally uncorrelated tentacle pulses (SUTPs) at 1 x 10(-5) mol l(-1). The NMDA antagonist, d-2-amino-5-phosphonopentanoic acid (D-AP5), counteracted the effects. NMDA/d-serine (1 x 10(-7) mol l(-1)) also caused a potentially significant (trend) decrease in the rate of small, behaviorally uncorrelated electrical body pulses (SUBPs) and rhythmic potentials (RPs). The effect was counteracted by D-AP5. The ectodermal contraction burst (CB) pacemaker system was unaffected by NMDA/d-serine. Our results indicate that glutamate, acting on NMDA/AMPA-kainate receptors, may cause opposing effects on the coordinating systems of tentacle and body-exciting the tentacle effectors and potentially causing an inhibition in the body column.

  19. Oxytocin/vasopressin-like immunoreactivity is present in the nervous system of hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Dierickx, K; Boer, G J

    1982-01-01

    Nerve cells have been found in hydra, which react with antisera to oxytocin, vasopressin and mesotocin. These nerve cells have a high density in the ectoderm of basal disk and tentacles and lower density in the ectoderm of peduncle, gastric region and hypostome. A very small number of nerve cells...

  20. Structure, expression, and developmental function of early divergent forms of metalloproteinases in Hydra

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Metalloproteinases have a critical role in a broad spectrum of cellular processes ranging from the break-down of extracellulax matrix to the processing of signal transduction-related proteins. These hydrolyticfunctions underlie a variety of mechanisms related to developmental processes as well as disease states.Structural analysis of metalloproteinases from both invertebrate and vertebrate species indicates that theseenzymes are highly conserved and arose early during metazoan evolution. In this regard, studies from vari-ous laboratories have reported that a number of classes of metalloproteinases are found in hydra, a memberof Cnidaria, the second oldest of existing animal phyla. These studies demonstrate that the hydra genomecontains at least three classes of metalloproteinases to include members of the 1) astacin class, 2) matrix met-alloproteinase class, and 3) neprilysin class. Functional studies indicate that these metalloproteinases playdiverse and important roles in hydra morphogenesis and cell differentiation as well as specialized functionsin adult polyps. This article will review the structure, expression, and function of these metalloproteinasesin hydra.

  1. The synaptonemal complex of basal metazoan hydra: more similarities to vertebrate than invertebrate meiosis model organisms.

    Science.gov (United States)

    Fraune, Johanna; Wiesner, Miriam; Benavente, Ricardo

    2014-03-20

    The synaptonemal complex (SC) is an evolutionarily well-conserved structure that mediates chromosome synapsis during prophase of the first meiotic division. Although its structure is conserved, the characterized protein components in the current metazoan meiosis model systems (Drosophila melanogaster, Caenorhabditis elegans, and Mus musculus) show no sequence homology, challenging the question of a single evolutionary origin of the SC. However, our recent studies revealed the monophyletic origin of the mammalian SC protein components. Many of them being ancient in Metazoa and already present in the cnidarian Hydra. Remarkably, a comparison between different model systems disclosed a great similarity between the SC components of Hydra and mammals while the proteins of the ecdysozoan systems (D. melanogaster and C. elegans) differ significantly. In this review, we introduce the basal-branching metazoan species Hydra as a potential novel invertebrate model system for meiosis research and particularly for the investigation of SC evolution, function and assembly. Also, available methods for SC research in Hydra are summarized.

  2. A comparison of metal accumulation by the cnidarian Hydra vulgaris directly from water or

    Directory of Open Access Journals (Sweden)

    Wanchamai Karntanut

    2007-05-01

    Full Text Available The cnidarian Hydra has been widely used to assess the acute toxicity of freshwater pollutants, but very little is known about pollutant accumulation by this animal. The purpose of this study was to measurethe accumulation of the three metals, i.e., copper, cadmium and zinc directly from water and also via its prey and to relate the recorded tissue concentrations to any change in biological activities. It was found thatcopper, cadmium and zinc all were accumulated in the tissues of Hydra exposed directly to the metals in water and also those exposed indirectly through feeding on contaminated prey. The bioconcentration factor(BCF recorded at 48 hours following direct uptake from water was greatest for copper (773, followed by cadmium (409 and zinc (125, although the greatest increase in body burden occurred with cadmium, Metal body burdens of Hydra fed on contaminated prey (Artemia increased in the same metal sequence as fordirect uptake from water and the increase was highest (250 times that of control Hydra for cadmium; however, biomagnification factors (BMFs were all < 1.0 indicating that there was little potential for increasingaccumulation via the food chain. There was significant inhibition of regeneration and bud production in polyps which had fed on cadmium-containing Artemia but not on copper or zinc- containing Artemia.

  3. Hydramacin-1, structure and antibacterial activity of a protein from the basal metazoan hydra

    NARCIS (Netherlands)

    Jung, S.; Dingley, A.J.; Augustin, R.; Anton-Erxleben, F.; Stanisak, M.; Gelhaus, C.; Gutsmann, T.; Hammer, M.U.; Podschun, R.; Bonvin, A.M.J.J.; Leippe, M.; Bosch, T.C.G.; Grötzinger, J.

    2009-01-01

    Hydramacin-1 is a novel antimicrobial protein recently discovered during investigations of the epithelial defense of the ancient metazoan Hydra. The amino acid sequence of hydramacin- 1 shows no sequence homology to any known antimicrobial proteins. Determination of the solution structure revealed t

  4. FoxO and stress responses in the cnidarian Hydra vulgaris.

    Directory of Open Access Journals (Sweden)

    Diane Bridge

    Full Text Available BACKGROUND: In the face of changing environmental conditions, the mechanisms underlying stress responses in diverse organisms are of increasing interest. In vertebrates, Drosophila, and Caenorhabditis elegans, FoxO transcription factors mediate cellular responses to stress, including oxidative stress and dietary restriction. Although FoxO genes have been identified in early-arising animal lineages including sponges and cnidarians, little is known about their roles in these organisms. METHODS/PRINCIPAL FINDINGS: We have examined the regulation of FoxO activity in members of the well-studied cnidarian genus Hydra. We find that Hydra FoxO is expressed at high levels in cells of the interstitial lineage, a cell lineage that includes multipotent stem cells that give rise to neurons, stinging cells, secretory cells and gametes. Using transgenic Hydra that express a FoxO-GFP fusion protein in cells of the interstitial lineage, we have determined that heat shock causes localization of the fusion protein to the nucleus. Our results also provide evidence that, as in bilaterian animals, Hydra FoxO activity is regulated by both Akt and JNK kinases. CONCLUSIONS: These findings imply that basic mechanisms of FoxO regulation arose before the evolution of bilaterians and raise the possibility that FoxO is involved in stress responses of other cnidarian species, including corals.

  5. Direct evidence for outflow of metal-enriched gas along the radio jets of Hydra A

    NARCIS (Netherlands)

    Kirkpatrick, C.C.; Gitti, M.; Cavagnolo, K.W.; McNamara, B.R.; David, L.P.; Nulsen, P.E.J.; Wise, M.W.

    2009-01-01

    Using deep Chandra observations of the Hydra A galaxy cluster, we examine the metallicity structure near the central galaxy and along its powerful radio source. We show that the metallicity of the intracluster medium is enhanced by up to 0.2 dex along the radio jets and lobes compared to the

  6. Profiling of adhesive-related genes in the freshwater cnidarian Hydra magnipapillata by transcriptomics and proteomics

    NARCIS (Netherlands)

    Rodrigues, Marcelo; Ostermann, Thomas; Kremeser, Leopold; Lindner, Herbert; Beisel, Christian; Berezikov, Eugene; Hobmayer, Bert; Ladurner, Peter

    2016-01-01

    The differentiated ectodermal basal disc cells of the freshwater cnidarian Hydra secrete proteinaceous glue to temporarily attach themselves to underwater surfaces. Using transcriptome sequencing and a basal disc-specific RNA-seq combined with in situ hybridisation a highly specific set of candidate

  7. Unstable normal modes of low T/W dynamical instabilities in differentially rotating stars

    CERN Document Server

    Saijo, Motoyuki

    2016-01-01

    We investigate the nature of low T/W dynamical instabilities in differentially rotating stars by means of linear perturbation. Here, T and W represent rotational kinetic energy and the gravitational binding energy of the star. This is the first attempt to investigate low T/W dynamical instabilities as a complete set of the eigenvalue problem. Our equilibrium configuration has "constant" specific angular momentum distribution, which potentially contains a singular solution in the perturbed enthalpy at corotation radius in linear perturbation. We find the unstable normal modes of differentially rotating stars by solving the eigenvalue problem along the equatorial plane of the star, imposing the regularity condition on the center and the vanished enthalpy at the oscillating equatorial surface. We find that the existing pulsation modes become unstable due to the existence of the corotation radius inside the star. The feature of the unstable mode eigenfrequency and its eigenfunction in the linear analysis roughly ...

  8. Rings of C2H in the Molecular Disks Orbiting TW Hya and V4046 Sgr

    CERN Document Server

    Kastner, J H; Gorti, U; Hily-Blant, P; Oberg, K; Forveille, T; Andrews, S; Wilner, D

    2015-01-01

    We have used the Submillimeter Array to image, at ~1" resolution, C2H(3-2) emission from the molecule-rich circumstellar disks orbiting the nearby, classical T Tauri star systems TW Hya and V4046 Sgr. The SMA imaging reveals that the C2H emission exhibits a ring-like morphology within each disk, the inner hole radius of the C2H ring within the V4046 Sgr disk (~70 AU) is somewhat larger than than of its counterpart within the TW Hya disk (~45 AU). We suggest that, in each case, the C2H emission likely traces irradiation of the tenuous surface layers of the outer disks by high-energy photons from the central stars.

  9. 投影机 爱普生EMP-TW20

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    在爱普生的EMP-TW系列家用投影机中,EMP-TW20是最新的一款低端产品。在外观方面,它仍保持了爱普生EMP-TW投影机简浩高质感的设计风格,而且乳白色的机身可以很容易地与家居环境融合.

  10. 200 TW 45 fs laser based on optical parametric chirped pulse amplification.

    Science.gov (United States)

    Lozhkarev, V V; Freidman, G I; Ginzburg, V N; Katin, E V; Khazanov, E A; Kirsanov, A V; Luchinin, G A; Mal'shakov, A N; Martyanov, M A; Palashov, O V; Poteomkin, A K; Sergeev, A M; Shaykin, A A; Yakovlev, I V; Garanin, S G; Sukharev, S A; Rukavishnikov, N N; Charukhchev, A V; Gerke, R R; Yashin, V E

    2006-01-01

    200 TW peak power has been achieved experimentally using a Cr:forsterite master oscillator at 1250 nm, a stretcher, three optical parametrical amplifiers based on KD*P (DKDP) crystals providing 14.5 J energy in the chirped pulse at 910 nm central wavelength, and a vacuum compressor. The final parametrical amplifier and the compressor are described in detail. Scaling of such architecture to multipetawatt power is discussed.

  11. BANYAN. IX. The Initial Mass Function and Planetary-mass Object Space Density of the TW HYA Association

    Science.gov (United States)

    Gagné, Jonathan; Faherty, Jacqueline K.; Mamajek, Eric E.; Malo, Lison; Doyon, René; Filippazzo, Joseph C.; Weinberger, Alycia J.; Donaldson, Jessica K.; Lépine, Sébastien; Lafrenière, David; Artigau, Étienne; Burgasser, Adam J.; Looper, Dagny; Boucher, Anne; Beletsky, Yuri; Camnasio, Sara; Brunette, Charles; Arboit, Geneviève

    2017-02-01

    A determination of the initial mass function (IMF) of the current, incomplete census of the 10 Myr-old TW Hya association (TWA) is presented. This census is built from a literature compilation supplemented with new spectra and 17 new radial velocities from ongoing membership surveys, as well as a reanalysis of Hipparcos data that confirmed HR 4334 (A2 Vn) as a member. Although the dominant uncertainty in the IMF remains census incompleteness, a detailed statistical treatment is carried out to make the IMF determination independent of binning while accounting for small number statistics. The currently known high-likelihood members are fitted by a log-normal distribution with a central mass of {0.21}-0.06+0.11 M ⊙ and a characteristic width of {0.8}-0.1+0.2 dex in the 12 M Jup–2 M ⊙ range, whereas a Salpeter power law with α ={2.2}-0.5+1.1 best describes the IMF slope in the 0.1–2 M ⊙ range. This characteristic width is higher than other young associations, which may be due to incompleteness in the current census of low-mass TWA stars. A tentative overpopulation of isolated planetary-mass members similar to 2MASS J11472421–2040204 and 2MASS J11193254–1137466 is identified: this indicates that there might be as many as {10}-5+13 similar members of TWA with hot-start model-dependent masses estimated at ∼5–7 M Jup, most of which would be too faint to be detected in 2MASS. Our new radial velocity measurements corroborate the membership of 2MASS J11472421–2040204, and secure TWA 28 (M8.5 γ), TWA 29 (M9.5 γ), and TWA 33 (M4.5 e) as members. The discovery of 2MASS J09553336–0208403, a young L7-type interloper unrelated to TWA, is also presented.

  12. Isolation and cultivation of endosymbiotic algae from green hydra and phylogenetic analysis of 18S rDNA sequences.

    Science.gov (United States)

    Kovacević, Goran; Franjević, Damjan; Jelencić, Biserka; Kalafatić, Mirjana

    2010-01-01

    Symbiotic associations are of wide significance in evolution and biodiversity. The green hydra is a typical example of endosymbiosis. In its gastrodermal myoepithelial cells it harbors the individuals of a unicellular green algae. Endosymbiotic algae from green hydra have been successfully isolated and permanently maintained in a stable clean lab culture for the first time. We reconstructed the phylogeny of isolated endosymbiotic algae using the 18S rRNA gene to clarify its current status and to validate the traditional inclusion of these endosymbiotic algae within the Chlorella genus. Molecular analyses established that different genera and species of unicellular green algae could be present as symbionts in green hydra, depending on the natural habitat of a particular strain of green hydra.

  13. Gry w podmiot. Szkic o (wczesnej twórczości Mladena Stilinovicia

    Directory of Open Access Journals (Sweden)

    Magdalena Bogusławska

    2016-10-01

    Full Text Available Games of a subject: A sketch of the (early works of Mladen Stilinović The article concerns the conceptualization of the subject in the works of the contemporary Croatian visual artist Mladen Stilinović. The object of analysis are most of all works (collages, texts from the 1970s and early 1980s, when the artist formulated the basis for his creative philosophy and at the same time determined the directions of their research. His system of reference were the socialist state order and the traditionalist, academic system of artistic practice, which he criticized from the perspectives of Diogenes, philosophical Cynicism and constructive anarchism. Until this day, the attitude of resistance is the main creative principle for Stilinović’s art. He sets strong, conscious and autonomous creator’s “I” against symbolic violence of different systems (political, ideological, educational, etc.. This “I” is not so much the material and object of expression as a space of play based on concpetualism and self-irony.   Gry w podmiot. Szkic o (wczesnej twórczości Mladena Stilinovicia Artykuł dotyczy konceptualizacji podmiotu w twórczości współczesnego chorwackiego artysty wizualnego – Mladena Stilinovicia. Przedmiotem analizy są przede wszystkim prace (kolaże, teksty z lat 70. i początku 80. XX wieku, kiedy to artysta formułował podstawy filozofii twórczej i określał kierunki swych poszukiwań. Układem odniesienia były dla niego wówczas socjalistyczny porządek państwa i tradycjonalistyczny, akademicki system praktyki artystycz­nej, które poddawał konsekwentnej krytyce z pozycji rozumnego, diogenesowskiego cynizmu i konstruktywnego anarchizmu. Do dziś postawa oporu jest dla Stilinovicia podstawową zasadą twórczą. Przemocy symbolicznej wszelkich systemów (politycznych, ideologicznych, edukacyjnych itp. przeciwstawia mocne, świadome i niezależne „ja” twórcy. Jest tu ono nie tyle tworzywem i przedmiotem ekspresji

  14. The Effect of Broadband Soft X-Rays in SO2-Containing Ices: Implications on the Photochemistry of Ices toward Young Stellar Objects

    Science.gov (United States)

    Pilling, S.; Bergantini, A.

    2015-10-01

    We investigate the effects produced mainly by broadband soft X-rays up to 2 keV (plus fast (˜keV) photoelectrons and low-energy (˜eV) induced secondary electrons) in the ice mixtures containing H2O:CO2:NH3:SO2 (10:1:1:1) at two different temperatures (50 and 90 K). The experiments are an attempt to simulate the photochemical processes induced by energetic photons in SO2-containing ices present in cold environments in the ices surrounding young stellar objects (YSO) and in molecular clouds in the vicinity of star-forming regions, which are largely illuminated by soft X-rays. The measurements were performed using a high-vacuum portable chamber from the Laboratório de Astroquímica e Astrobiologia (LASA/UNIVAP) coupled to the spherical grating monochromator beamline at the Brazilian Synchrotron Light Source (LNLS) in Campinas, Brazil. In situ analyses were performed by a Fourier transform infrared spectrometer. Sample processing revealed the formation of several organic molecules, including nitriles, acids, and other compounds such as H2O2, H3O+, SO3, CO, and OCN-. The dissociation cross section of parental species was on the order of (2-7) × 10-18 cm2. The ice temperature does not seem to affect the stability of SO2 in the presence of X-rays. Formation cross sections of new species produced were also determined. Molecular half-lives at ices toward YSOs due to the presence of incoming soft X-rays were estimated. The low values obtained employing two different models of the radiation field of YSOs (TW Hydra and typical T-Tauri star) reinforce that soft X-rays are indeed a very efficient source of molecular dissociation in such environments.

  15. Spectroscopic Confirmation of the Dwarf Galaxies Hydra II and Pisces II and the Globular Cluster Laevens 1

    CERN Document Server

    Kirby, Evan N; Cohen, Judith G

    2015-01-01

    We present Keck/DEIMOS spectroscopy of stars in the recently discovered Milky Way satellites Hydra II, Pisces II, and Laevens 1. We measured a velocity dispersion of 5.4 (+3.6 -2.4) km/s for Pisces II, but we did not resolve the velocity dispersions of Hydra II or Laevens 1. We marginally resolved the metallicity dispersions of Hydra II and Pisces II but not Laevens 1. Furthermore, Hydra II and Pisces II obey the luminosity-metallicity relation for Milky Way dwarf galaxies ( = -2.02 +/- 0.08 and -2.45 +/- 0.07, respectively), whereas Laevens 1 does not ( = -1.68 +/- 0.05). The kinematic and chemical properties suggest that Hydra II and Pisces II are dwarf galaxies, and Laevens 1 is a globular cluster. We determined that two of the previously observed blue stars near the center of Laevens 1 are not members of the cluster. A third blue star has ambiguous membership. If it is a member, we suggest that it could be a Type II Cepheid variable. Hydra II has a radial velocity = 303.1 +/- 1.4 km/s, similar to the lea...

  16. Structural and Sequence Similarities of Hydra Xeroderma Pigmentosum A Protein to Human Homolog Suggest Early Evolution and Conservation

    Directory of Open Access Journals (Sweden)

    Apurva Barve

    2013-01-01

    Full Text Available Xeroderma pigmentosum group A (XPA is a protein that binds to damaged DNA, verifies presence of a lesion, and recruits other proteins of the nucleotide excision repair (NER pathway to the site. Though its homologs from yeast, Drosophila, humans, and so forth are well studied, XPA has not so far been reported from protozoa and lower animal phyla. Hydra is a fresh-water cnidarian with a remarkable capacity for regeneration and apparent lack of organismal ageing. Cnidarians are among the first metazoa with a defined body axis, tissue grade organisation, and nervous system. We report here for the first time presence of XPA gene in hydra. Putative protein sequence of hydra XPA contains nuclear localization signal and bears the zinc-finger motif. It contains two conserved Pfam domains and various characterized features of XPA proteins like regions for binding to excision repair cross-complementing protein-1 (ERCC1 and replication protein A 70 kDa subunit (RPA70 proteins. Hydra XPA shows a high degree of similarity with vertebrate homologs and clusters with deuterostomes in phylogenetic analysis. Homology modelling corroborates the very close similarity between hydra and human XPA. The protein thus most likely functions in hydra in the same manner as in other animals, indicating that it arose early in evolution and has been conserved across animal phyla.

  17. THM-GTRF: New Spider meshes, New Hydra-TH runs

    Energy Technology Data Exchange (ETDEWEB)

    Bakosi, Jozsef [Los Alamos National Laboratory; Christon, Mark A. [Los Alamos National Laboratory; Francois, Marianne M. [Los Alamos National Laboratory; Lowrie, Robert B. [Los Alamos National Laboratory; Nourgaliev, Robert [Los Alamos National Laboratory

    2012-06-20

    Progress is reported on computational capabilities for the grid-to-rod-fretting (GTRF) problem of pressurized water reactors. Numeca's Hexpress/Hybrid mesh generator is demonstrated as an excellent alternative to generating computational meshes for complex flow geometries, such as in GTRF. Mesh assessment is carried out using standard industrial computational fluid dynamics practices. Hydra-TH, a simulation code developed at LANL for reactor thermal-hydraulics, is demonstrated on hybrid meshes, containing different element types. A series of new Hydra-TH calculations has been carried out collecting turbulence statistics. Preliminary results on the newly generated meshes are discussed; full analysis will be documented in the L3 milestone, THM.CFD.P5.05, Sept. 2012.

  18. Searching for star-forming galaxies in the Fornax and Hydra clusters

    Science.gov (United States)

    Vaduvescu, O.; Kehrig, C.; Vilchez, J. M.; Unda-Sanzana, E.

    2011-09-01

    Context. The formation and evolution of dwarf galaxies is relatively difficult to understand because of their faint emission in all regimes that require large aperture telescopes. Aims: We intend to study the evolution of star-forming dwarf galaxies in clusters. We selected Fornax and Hydra clusters to complement our previous study of Virgo. On the basis of available literature data, we selected ten star-forming candidates in Fornax and another ten objects in Hydra. Methods: We used Gemini South with GMOS to acquire Hα images necessary to detect star-forming regions in the two galaxy samples. We then performed long-slit spectroscopy for the brightest six candidates, to derive their chemical properties. Finally, we employed the VLT with HAWK-I to observe all galaxies in the K' band to derive their main physical properties. Results: We studied the morphology of our two samples, finding five objects in Fornax and six in Hydra with structures consistent with those of star-forming dwarfs, i.e., dwarf irregulars (dIs) or blue compact dwarfs (BCDs). About four other objects are probably dwarf spirals, while three objects remained undetected in both visible and near infrared. On the basis of visible bright emission lines, we derived oxygen abundances for ten star-forming candidates with values between 8.00 ≤ 12+log(O/H) ≤8.78. Conclusions: Most fundamental properties of star-forming galaxies in Fornax and Hydra appear similar to corresponding properties of dIs and BCDs from Virgo and the local volume (LV). The luminosity-metallicity and metallicity-gas fraction relations in the LV and Virgo appear to be followed by Fornax and Hydra samples, suggesting that the chemical evolution of the two clusters seems consistent with the predictions from the closed box model, although larger samples are needed to investigate the role of possible environmental effects. Star-forming dwarfs (dIs and BCDs) in different environments appear to follow different mass-metallicity relations

  19. Variable Stars in the Field of the Hydra II Ultra-faint Dwarf Galaxy

    Science.gov (United States)

    Vivas, A. Katherina; Olsen, Knut; Blum, Robert; Nidever, David L.; Walker, Alistair R.; Martin, Nicolas F.; Besla, Gurtina; Gallart, Carme; van der Marel, Roeland P.; Majewski, Steven R.; Kaleida, Catherine C.; Muñoz, Ricardo R.; Saha, Abhijit; Conn, Blair C.; Jin, Shoko

    2016-05-01

    We report the discovery of one RR Lyrae star in the ultra-faint satellite galaxy Hydra II based on time series photometry in the g, r and i bands obtained with the Dark Energy Camera at Cerro Tololo Inter-American Observatory, Chile. The association of the RR Lyrae star discovered here with Hydra II is clear because is located at 42\\prime\\prime from the center of the dwarf, well within its half-light radius of 102\\prime\\prime . The RR Lyrae star has a mean magnitude of i=21.30+/- 0.04 which is too faint to be a field halo star. This magnitude translates to a heliocentric distance of 151 ± 8 kpc for Hydra II; this value is ∼ 13% larger than the estimate from the discovery paper based on the average magnitude of several blue horizontal branch star candidates. The new distance implies a slightly larger half-light radius of {76}-10+12 pc and a brighter absolute magnitude of {M}V=-5.1+/- 0.3, which keeps this object within the realm of the dwarf galaxies. A comparison with other RR Lyrae stars in ultra-faint systems indicates similar pulsational properties among them, which are different to those found among halo field stars and those in the largest of the Milky Way satellites. We also report the discovery of 31 additional short period variables in the field of view (RR Lyrae, SX Phe, eclipsing binaries, and a likely anomalous cepheid) which are likely not related with Hydra II.

  20. Toxicity of Polychlorinated Diphenyl Ethers in Hydra Attenuata and in Rat Whole Embryo Culture

    Science.gov (United States)

    1991-05-01

    were fed freshly hatched Artemia naupii ( brine shrimp ) once a day. The shrimp eggs (approximately 15 ml) were hydrated in 1% NaCl for approximately 2...all other chemicals were from Sigma (St. Louis, MO.). Brine shrimp eggs were purchased from Carolina Biological Supply, Burlington, NC. The original...days at room temperature. Eggs were aerated throughout the hatching period. Prior to feeding to the hydra, brine shrimp were siphoned into a fish net

  1. Notch-signalling is required for head regeneration and tentacle patterning in Hydra.

    Science.gov (United States)

    Münder, Sandra; Tischer, Susanne; Grundhuber, Maresa; Büchels, Nathalie; Bruckmeier, Nadine; Eckert, Stefanie; Seefeldt, Carolin A; Prexl, Andrea; Käsbauer, Tina; Böttger, Angelika

    2013-11-01

    Local self-activation and long ranging inhibition provide a mechanism for setting up organising regions as signalling centres for the development of structures in the surrounding tissue. The adult hydra hypostome functions as head organiser. After hydra head removal it is newly formed and complete heads can be regenerated. The molecular components of this organising region involve Wnt-signalling and β-catenin. However, it is not known how correct patterning of hypostome and tentacles are achieved in the hydra head and whether other signals in addition to HyWnt3 are needed for re-establishing the new organiser after head removal. Here we show that Notch-signalling is required for re-establishing the organiser during regeneration and that this is due to its role in restricting tentacle activation. Blocking Notch-signalling leads to the formation of irregular head structures characterised by excess tentacle tissue and aberrant expression of genes that mark the tentacle boundaries. This indicates a role for Notch-signalling in defining the tentacle pattern in the hydra head. Moreover, lateral inhibition by HvNotch and its target HyHes are required for head regeneration and without this the formation of the β-catenin/Wnt dependent head organiser is impaired. Work on prebilaterian model organisms has shown that the Wnt-pathway is important for setting up signalling centres for axial patterning in early multicellular animals. Our data suggest that the integration of Wnt-signalling with Notch-Delta activity was also involved in the evolution of defined body plans in animals.

  2. Spectral and Temporal Characteristics of LS PEG and TW PIC Using XMM-NEWTON Data

    Science.gov (United States)

    Talebpour Sheshvan, Nasrin; Balman, Solen

    2016-07-01

    We report the analysis of archival XMM-Newton X-ray observations of LS Peg and TW Pic. These are Cataclysmic Variables (CVs) suggested as Intermediate Polars (IPs), but unconfirmed in the X-rays. Identification of several periodic oscillations in the optical band hint them as IPs. Unlike the previous spectral analysis on the EPIC-MOS data by fitting a hot optically thin plasma emission model with a single temperature for LS Peg, we simultaneously fitted all EPIC spectrum (pn+MOS) using a composite model of absorption for interstellar medium (tbabs) with two different partial covering absorbers (pcfabs) including a multitemperature plasma emission component (cevmkl) and a Gaussian emission line at 6.4 keV. TW Pic is best modeled in a similar manner with only one partial covering absorber and an extra Gaussian emission line at 6.7 keV. LS Peg has a maximum plasma temperature of ˜14.8 keV with an X-ray luminosity of ˜5×10^{32}ergs ^{-1} translating to an accretion rate of ˜1.27×10^{-10}M _{⊙}yr ^{-1}. TW Pic shows kT _{max} ˜38.7 keV with an X-ray luminosity around 1.6×10^{33}ergs ^{-1} at an accretion rate of ˜4×10^{-10}M _{⊙}yr ^{-1}. In addition, we discuss orbital modulations in the X-rays and power spectral analysis, and derive the EPIC pn spectra for orbital minimum and orbital maximum phases for both sources. We elaborate on the geometry of accretion and absorption in the X-ray emitting regions of both sources with articulation on the magnetic nature.

  3. Advances in HYDRA and its application to simulations of Inertial Confinement Fusion targets

    Science.gov (United States)

    Marinak, M. M.; Kerbel, G. D.; Koning, J. M.; Patel, M. V.; Sepke, S. M.; Brown, P. N.; Chang, B.; Procassini, R.; Veitzer, S. A.

    2008-11-01

    We will outline new capabilities added to the HYDRA 2D/3D multiphysics ICF simulation code. These include a new SN multigroup radiation transport package (1D), constitutive models for elastic-plastic (strength) effects, and a mix model. A Monte Carlo burn package is being incorporated to model diagnostic signatures of neutrons, gamma rays and charged particles. A 3D MHD package that treats resistive MHD is available. Improvements to HYDRA's implicit Monte Carlo photonics package, including the addition of angular biasing, now enable integrated hohlraum simulations to complete in substantially shorter time. The heavy ion beam deposition package now includes a new model for ion stopping power developed by the Tech-X Corporation, with improved accuracy below the Bragg peak. Examples will illustrate HYDRA's enhanced capabilities to simulate various aspects of inertial confinement fusion targets.This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344. The work of Tech-X personnel was funded by the Department of Energy under Small Business Innovation Research Contract No. DE-FG02-03ER83797.

  4. Peptide-gated ion channels and the simple nervous system of Hydra.

    Science.gov (United States)

    Gründer, Stefan; Assmann, Marc

    2015-02-15

    Neurons either use electrical or chemical synapses to communicate with each other. Transmitters at chemical synapses are either small molecules or neuropeptides. After binding to their receptors, transmitters elicit postsynaptic potentials, which can either be fast and transient or slow and longer lasting, depending on the type of receptor. Fast transient potentials are mediated by ionotropic receptors and slow long-lasting potentials by metabotropic receptors. Transmitters and receptors are well studied for animals with a complex nervous system such as vertebrates and insects, but much less is known for animals with a simple nervous system like Cnidaria. As cnidarians arose early in animal evolution, nervous systems might have first evolved within this group and the study of neurotransmission in cnidarians might reveal an ancient mechanism of neuronal communication. The simple nervous system of the cnidarian Hydra extensively uses neuropeptides and, recently, we cloned and functionally characterized an ion channel that is directly activated by neuropeptides of the Hydra nervous system. These results demonstrate the existence of peptide-gated ion channels in Hydra, suggesting they mediate fast transmission in its nervous system. As related channels are also present in the genomes of the cnidarian Nematostella, of placozoans and of ctenophores, it should be considered that the early nervous systems of cnidarians and ctenophores have co-opted neuropeptides for fast transmission at chemical synapses.

  5. Variable stars in the field of the Hydra II ultra-faint dwarf galaxy

    CERN Document Server

    Vivas, A Katherina; Olsen, Knut; Blum, Robert; Walker, Alistair; Martin, Nicolas; Besla, Gurtina; Gallart, Carme; van der Marel, Roeland; Majewski, Steven; Kaleida, Catherine; Muñoz, Ricardo; Conn, Blair; Jin, Shoko

    2015-01-01

    We report the discovery of one RR Lyrae star in the ultra--faint satellite galaxy Hydra II based on time series photometry in the g, r and i bands obtained with the Dark Energy Camera at Cerro Tololo Interamerican Observatory, Chile. The RR Lyrae star has a mean magnitude of $i = 21.30\\pm 0.04$ which translates to a heliocentric distance of $151\\pm 8$ kpc for Hydra II; this value is $\\sim 13\\%$ larger than the estimate from the discovery paper based on the average magnitude of several blue horizontal branch star candidates. The new distance implies a slightly larger half-light radius of $76^{+12}_{-10}$ pc and a brighter absolute magnitude of $M_V = -5.1 \\pm 0.3$, which keeps this object within the realm of the dwarf galaxies. The pulsational properties of the RR Lyrae star ($P=0.645$ d, $\\Delta g = 0.68$ mag) suggest Hydra II may be a member of the intermediate Oosterhoff or Oosterhoff II group. A comparison with other RR Lyrae stars in ultra--faint systems indicates similar pulsational properties among them...

  6. Impact of Carbon Nano-Onions on Hydra vulgaris as a Model Organism for Nanoecotoxicology

    Directory of Open Access Journals (Sweden)

    Valentina Marchesano

    2015-08-01

    Full Text Available The toxicological effects of pristine and chemically modified carbon nano-onions (CNOs on the development of the freshwater polyp Hydra vulgaris were investigated in order to elucidate the ecotoxicological effects of CNOs. Chemical modifications of the CNOs were accomplished by surface functionalization with benzoic acid, pyridine and pyridinium moieties. thermogravimetric analysis (TGA, Fourier transform infrared spectroscopy (FT-IR and Raman spectroscopy confirmed the covalent surface functionalization of CNOs. Hydra specimens were exposed to the carbon nanomaterials by prolonged incubation within their medium. Uptake was monitored by optical microscopy, and the toxicological effects of the CNOs on Hydra behavior, morphology, as well as the long-term effects on the development and reproductive capability were examined. The obtained data revealed the absence of adverse effects of CNOs (in the range 0.05–0.1 mg/L in vivo at the whole animal level. Together with previously performed in vitro toxicological analyses, our findings indicate the biosafety of CNOs and the feasibility of employing them as materials for biomedical applications.

  7. Toxic effects of bisphenol A on sexual and asexual reproduction in Hydra oligactis.

    Science.gov (United States)

    Fukuhori, N; Kitano, M; Kimura, H

    2005-05-01

    Hydra oligactis, an evolutionarily primitive invertebrate, produced eggs or testes (sexual reproduction) when starved at 10 degrees C, and produced buds (asexual reproduction) when fed at 20 degrees C. Bisphenol A (BPA) at 2-4 mg/L given to male or female hydra had adverse effects on both sexual and asexual reproduction. Despite the estrogenic nature of BPA, testis formation and egg formation were similarly affected. The doses causing these acute toxicities were comparable to those reported earlier in aquatic invertebrates and were much higher than environmentally detected doses, at which the disruption of the endocrine system has been reported in fishes. All these facts indicate that the adverse effects are the results of general toxicity and may not be due to the estrogenic function of the compound. On the other hand, we found that BPA at 1 mg/L (a dose still much higher than environmental doses) stimulated asexual reproduction. No such stimulation of sexual reproduction was seen. When male hydras were fed at 10 degrees C, they produced both buds and testes simultaneously. BPA at 0.5 and 1 mg/L under this condition also stimulated asexual reproduction, whereas it suppressed sexual reproduction more severely than BPA at 2-3 mg/L. There may be some interaction between processes involved in sexual and asexual reproduction under this condition, and the stimulation of asexual reproduction by BPA may cause suppression of sexual reproduction.

  8. Patterning processes in aggregates of Hydra cells visualized with the monoclonal antibody, TS19.

    Science.gov (United States)

    Sato, M; Bode, H R; Sawada, Y

    1990-10-01

    The monoclonal antibody, TS19, (Heimfeld et al., 1985), labels the apical surface of ectodermal epithelial cells of tentacles and lower peduncles in Hydra. To investigate the patterning process in a tissue whose original pattern was completely destroyed, the TS19 staining pattern was examined in developing aggregates of Hydra cells. Two types of aggregates were prepared. G-aggregates were made from tissue of the gastric portion of animals and RG-aggregates from gastric tissue allowed to regenerate for 24 hr before making aggregates. G-aggregates were initially TS19-negative, and later dim and uniformly TS19-positive. Thereafter, TS19 staining broke up into brightly stained and unstained regions. The brightly staining regions developed into head or foot structures. The TS19 pattern in RG-aggregates developed differently. Since the initial aggregates contained cells of regenerating tips, they started with TS19-positive cells as well as TS19-negative cells. The numbers of brightly staining TS19-positive cells increased with time. Some patches of these cells developed into head or foot structures, while others did not. These results and a simulation using a reaction-diffusion model suggest that the changes in activation levels affected the temporal changes in the pattern of TS19 staining, and that the de novo pattern formation in hydra can be explained in terms of a process involving activation and inhibition properties.

  9. Simulation studies of laser wakefield acceleration based on typical 100 TW laser facilities

    Institute of Scientific and Technical Information of China (English)

    LI Da-Zhang; GAO Jie; ZHU Xiong-Wei; HE An

    2011-01-01

    In this paper,2-D Particle-In-Cell simulations are made for Laser Wakefield Accelerations(LWFA).As in a real experiment,we perform plasma density scanning for typical 100 TW laser facilities.Several basic laws for self-injected acceleration in a bubble regime are presented.According to these laws,we choose a proper plasma density and then obtain a high quality quasi-monoenergetic electron bunch with arms energy of more than 650 MeV and a bunch length of less than 1.5 μn.

  10. LIGHT SOURCE: TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Science.gov (United States)

    Yan, Li-Xm; Du, Ying-Chao; Du, Qiang; Li, Ren-Kai; Hua, Jian-Fei; Huang, Wen-Hui; Tang, Chuan-Xiang

    2009-06-01

    A TW (Tera Watt) laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source (TTX) is being built. Both UV (ultraviolet) laser pulse for driving the photocathode radio-frequency (RF) gun and the IR (infrared) laser pulse as the electron-beam-scattered-light are provided by the system. Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  11. TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Institute of Scientific and Technical Information of China (English)

    YAN Li-Xin; DU Ying-Chao; DU Qiang; LI Ren-Kai; HUA Jian-Fei; HUANG Wen-Hui; TANG Chuan-Xiang

    2009-01-01

    A TW(Tera Watt)laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source(TTX)is being built.Both UV(ultraviolet)laser pulse for driving the photocathode radiofrequency(RF)gun and the IR(infrared)laser pulse as the electron-beam-scattered-light are provided by the system.Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  12. Rapid divergence of histones in Hydrozoa (Cnidaria) and evolution of a novel histone involved in DNA damage response in hydra.

    Science.gov (United States)

    Reddy, Puli Chandramouli; Ubhe, Suyog; Sirwani, Neha; Lohokare, Rasika; Galande, Sanjeev

    2017-08-01

    Histones are fundamental components of chromatin in all eukaryotes. Hydra, an emerging model system belonging to the basal metazoan phylum Cnidaria, provides an ideal platform to understand the evolution of core histone components at the base of eumetazoan phyla. Hydra exhibits peculiar properties such as tremendous regenerative capacity, lack of organismal senescence and rarity of malignancy. In light of the role of histone modifications and histone variants in these processes it is important to understand the nature of histones themselves and their variants in hydra. Here, we report identification of the complete repertoire of histone-coding genes in the Hydra magnipapillata genome. Hydra histones were classified based on their copy numbers, gene structure and other characteristic features. Genomic organization of canonical histone genes revealed the presence of H2A-H2B and H3-H4 paired clusters in high frequency and also a cluster with all core histones along with H1. Phylogenetic analysis of identified members of H2A and H2B histones suggested rapid expansion of these groups in Hydrozoa resulting in the appearance of unique subtypes. Amino acid sequence level comparisons of H2A and H2B forms with bilaterian counterparts suggest the possibility of a highly mobile nature of nucleosomes in hydra. Absolute quantitation of transcripts confirmed the high copy number of histones and supported the canonical nature of H2A. Furthermore, functional characterization of H2A.X.1 and a unique variant H2A.X.2 in the gastric region suggest their role in the maintenance of genome integrity and differentiation processes. These findings provide insights into the evolution of histones and their variants in hydra. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. Kerr self-defocusing of multiple filaments in TW peak power UV laser beam

    Science.gov (United States)

    Zvorykin, V. D.; Goncharov, S. A.; Ionin, A. A.; Mokrousova, D. V.; Ryabchuk, S. V.; Seleznev, L. V.; Shutov, A. V.; Smetanin, I. V.; Sunchugasheva, E. S.; Ustinovskii, N. N.

    2016-12-01

    An effective suppression of multiple filamentation of the sub-TW peak power supercritical laser beam in xenon gas was demonstrated in direct amplification of subpicosecond UV pulses at Ti:sapphire/KrF laser facility GARPUN-MTW. A large negative nonlinear refractive index due to a two-photon resonance of KrF laser radiation with Xe 6p{{≤ft[1/2\\right]}0} state ensured Kerr self-defocusing of a few hundred filaments with a local peak intensity of ~0.2 TW cm-2, 200-fold higher than the average one over the beam cross section, and thus homogenized the laser beam. UV filaments in Xe produced a narrow-angle monochromatic coherent cone emission at 828 nm wavelength due to stimulated hyper-Raman scattering and amplified spontaneous emission at the transition 6p{{≤ft[1/2\\right]}0}\\to 6s≤ft[3/2\\right]10 .

  14. Low temperature thermal windowing (TW) thermally stimulated depolarization current (TSDC) setup

    Science.gov (United States)

    Jain, Deepti; Sharath Chandra, L. S.; Nath, R.; Ganesan, V.

    2012-02-01

    We report here the design and implementation of a precise and easy to operate thermally stimulated depolarization current (TSDC) measurement setup for temperature range 77-400 K. The sample loading is made simple by sandwiching the sample between two copper disk electrodes using a spring-shaft arrangement. The salient features of the setup are precise thermal windowing (TW) capability and linear heating rate over the entire temperature range. The resolution in the measurement of depolarization current is of the order of 7×10-14 A. This is achieved by means of good electrical insulation of the electrodes from the rest of the setup and utilization of low noise circuitry. Precision of the system is demonstrated by its capability to resolve constituent relaxations present in complex relaxation processes using the TW experiments. Study and detection of glass transition processes in polyethylene terephthalate, four relaxation processes in polymethyl methacrylate, glass and crystallization transitions along with the onset of ferroelectric Curie transitions in polyvinylidene fluoride and characterization of electret state in amino acids l-arginine, phenylalanine, tyrosine, tryptophan, glutamic acid, glutamine and methionine show the versatility of our setup.

  15. Chasing Shadows: Rotation of the Azimuthal Asymmetry in the TW Hya Disk

    Science.gov (United States)

    Debes, John H.; Poteet, Charles A.; Jang-Condell, Hannah; Gaspar, Andras; Hines, Dean; Kastner, Joel H.; Pueyo, Laurent; Rapson, Valerie; Roberge, Aki; Schneider, Glenn; hide

    2017-01-01

    We have obtained new images of the protoplanetary disk orbiting TW Hya in visible, total intensity light with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST), using the newly commissioned BAR5 occulter. These HSTSTIS observations achieved an inner working angle of approximately 0 "2, or11.7 au, probing the system at angular radii coincident with recent images of the disk obtained by ALMA and in polarized intensity near-infrared light. By comparing our new STIS images to those taken with STIS in 2000 and with NICMOS in 1998, 2004, and 2005, we demonstrate that TW Hyas azimuthal surface brightness asymmetry moves coherently in position angle. Between 50 au and 141 au we measure a constant angular velocity in the azimuthal brightness asymmetry of 22.deg7 yr(exp -1) in a counterclockwise direction, equivalent to a period of 15.9yrassuming circular motion. Both the (short) inferred period and lack of radial dependence of the moving shadow pattern are inconsistent with Keplerian rotation at these disk radii. We hypothesize that the asymmetry arises from the fact that the disk interior to 1 au is inclined and precessing owing to a planetary companion, thus partially shadowing the outer disk. Further monitoring of this and other shadows on protoplanetary disks potentially opens anew avenue for indirectly observing the sites of planet formation.

  16. Toward TW-Level, Hard X-Ray Pulses at LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Fawley, W.M.; Frisch, J.; Huang, Z.; Jiao, Y.; Nuhn, H.-D.; /SLAC; Pellegrini, C.; /SLAC /UCLA; Reiche, S.; /PSI, Villigen; Wu, J,; /SLAC

    2011-12-13

    Coherent diffraction imaging of complex molecules such as proteins requires a large number (e.g., {approx} 10{sup 13}/pulse) of hard X-ray photons within a time scale of {approx} 10 fs or less. This corresponds to a peak power of {approx} 1 TW, much larger than that currently generated by LCLS or other proposed X-ray free electron lasers (FELs). We study the feasibility of producing such pulses using a LCLS-like, low charge electron beam, as will be possible in the LCLS-II upgrade project, employing a configuration beginning with a SASE amplifier, followed by a 'self-seeding' crystal monochromator, and finishing with a long tapered undulator. Our results suggest that TW-level output power at 8.3 keV is possible from a total undulator system length around 200 m. In addition power levels larger than 100 GW are generated at the third harmonic. We present a tapering strategy that extends the original 'resonant particle' formalism by optimizing the transport lattice to maximize optical guiding and enhance net energy extraction. We discuss the transverse and longitudinal coherence properties of the output radiation pulse and the expected output pulse energy sensitivity, both to taper errors and to power fluctuations on the monochromatized SASE seed.

  17. A new case of neuropeptide coexpression (RGamide and LWamides) in Hydra, found by whole-mount, two-color double-labeling in situ hybridization

    DEFF Research Database (Denmark)

    Hansen, Georg N; Williamson, Michael; Grimmelikhuijzen, Cornelis J P

    2002-01-01

    The freshwater polyp Hydra has a primitive nervous system that expresses at least six different neuropeptide genes: (1) three genes, coding for the preprohormones-A, -B, and -C that each gives rise to a variety of peptides with the C-terminal sequence Arg-Phe-NH(2) (the Hydra-RFamides); (2) one g...

  18. 'Abnormal' angle response curves of TW/Rs for near zero tilt and high tilt channeling implants

    Energy Technology Data Exchange (ETDEWEB)

    Guo Baonian; Gossmann, Hans-Joachim; Toh, Terry; Colombeau, Benjamin; Todorov, Stan; Sinclair, Frank; Shim, Kyu-Ha; Henry, Todd [Applied Materials - Varian Semiconductor Equipment, 35 Dory Road, Gloucester, MA 01930 (United States)

    2012-11-06

    Angle control has been widely accepted as the key requirement for ion implantation in semiconductor device processing. From an ion implanter point of view, the incident ion direction should be measured and corrected by suitable techniques, such as XP-VPS for the VIISta implanter platform, to ensure precision ion placement in device structures. So called V-curves have been adopted to generate the wafer-based calibration using channeling effects as the Si lattice steer ions into a channeling direction. Thermal Wave (TW) or sheet resistance (Rs) can be used to determine the minimum of the angle response curve. Normally it is expected that the TW and Rs have their respective minima at identical angles. However, the TW and Rs response to the angle variations does depend on factors such as implant species, dose, and wafer temperature. Implant damage accumulation effects have to be considered for data interpretation especially for some 'abnormal' V-curve data. In this paper we will discuss some observed 'abnormal' angle responses, such as a) TW/Rs reverse trend for Arsenic beam, 2) 'W' shape of Rs Boron, and 3) apparent TW/Rs minimum difference for high tilt characterization, along with experimental data and TCAD simulations.

  19. RNAseq versus genome-predicted transcriptomes: a large population of novel transcripts identified in an Illumina-454 Hydra transcriptome.

    Science.gov (United States)

    Wenger, Yvan; Galliot, Brigitte

    2013-03-25

    Evolutionary studies benefit from deep sequencing technologies that generate genomic and transcriptomic sequences from a variety of organisms. Genome sequencing and RNAseq have complementary strengths. In this study, we present the assembly of the most complete Hydra transcriptome to date along with a comparative analysis of the specific features of RNAseq and genome-predicted transcriptomes currently available in the freshwater hydrozoan Hydra vulgaris. To produce an accurate and extensive Hydra transcriptome, we combined Illumina and 454 Titanium reads, giving the primacy to Illumina over 454 reads to correct homopolymer errors. This strategy yielded an RNAseq transcriptome that contains 48'909 unique sequences including splice variants, representing approximately 24'450 distinct genes. Comparative analysis to the available genome-predicted transcriptomes identified 10'597 novel Hydra transcripts that encode 529 evolutionarily-conserved proteins. The annotation of 170 human orthologs points to critical functions in protein biosynthesis, FGF and TOR signaling, vesicle transport, immunity, cell cycle regulation, cell death, mitochondrial metabolism, transcription and chromatin regulation. However, a majority of these novel transcripts encodes short ORFs, at least 767 of them corresponding to pseudogenes. This RNAseq transcriptome also lacks 11'270 predicted transcripts that correspond either to silent genes or to genes expressed below the detection level of this study. We established a simple and powerful strategy to combine Illumina and 454 reads and we produced, with genome assistance, an extensive and accurate Hydra transcriptome. The comparative analysis of the RNAseq transcriptome with genome-predicted transcriptomes lead to the identification of large populations of novel as well as missing transcripts that might reflect Hydra-specific evolutionary events.

  20. “Is the Hydra the Enemy?” A Review of English Language as Hydra: Its Impacts on Non-English Language Cultures

    Directory of Open Access Journals (Sweden)

    Corazon D. Villareal

    2012-12-01

    Full Text Available The book, part of the series on Linguistic Diversity and Language Rights of Multilingual Matters, seeks "to promote multilingualism as a resource, the maintenance of the linguistic diversity and development of and respect for linguistic human rights worldwide through the dissemination of theoretical and empirical research"(ii. The context for this advocacy is English whose domain is perceived to have reduced linguistic and cultural diversity; this encounter is the core concern of the book, as the title suggests. The contributors unabashedly articulate their disgust and rage against this hydra through a seemingly inexhaustible arsenal of metaphors - thief, bully, juggernaut,an intractable governess, "a partner in crime," "an overstaying auntie," etc. The tone is combative, sometimes veering dangerously close to simplistic name-calling and clichéd emotionalism. So it seems.

  1. KINEMATICS OF THE CO GAS IN THE INNER REGIONS OF THE TW Hya DISK

    Energy Technology Data Exchange (ETDEWEB)

    Rosenfeld, Katherine A.; Qi Chunhua; Andrews, Sean M.; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Corder, Stuartt A. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Dullemond, C. P. [Institut fuer Theoretische Astrophysik, Universitaet Heidelberg, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Lin Shinyi [Department of Physics, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Hughes, A. M. [Department of Astronomy, University of California at Berkeley, 601 Campbell Hall, Berkeley, CA 94720 (United States); D' Alessio, Paola [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 72-3 (Xangari), 58089 Morelia, Michoacan (Mexico); Ho, P. T. P. [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 106, Taiwan (China)

    2012-10-01

    We present a detailed analysis of the spatially and spectrally resolved {sup 12}CO J = 2-1 and J = 3-2 emission lines from the TW Hya circumstellar disk, based on science verification data from the Atacama Large Millimeter/submillimeter Array (ALMA). These lines exhibit substantial emission in their high-velocity wings (with projected velocities out to 2.1 km s{sup -1}, corresponding to intrinsic orbital velocities >20 km s{sup -1}) that trace molecular gas as close as 2 AU from the central star. However, we are not able to reproduce the intensity of these wings and the general spatio-kinematic pattern of the lines with simple models for the disk structure and kinematics. Using three-dimensional non-local thermodynamic equilibrium molecular excitation and radiative transfer calculations, we construct some alternative models that successfully account for these features by modifying either (1) the temperature structure of the inner disk (inside the dust-depleted disk cavity; r < 4 AU), (2) the intrinsic (Keplerian) disk velocity field, or (3) the distribution of disk inclination angles (a warp). The latter approach is particularly compelling because a representative warped disk model qualitatively reproduces the observed azimuthal modulation of optical light scattered off the disk surface. In any model scenario, the ALMA data clearly require a substantial molecular gas reservoir located inside the region where dust optical depths are known to be substantially diminished in the TW Hya disk, in agreement with previous studies based on infrared spectroscopy. The results from these updated model prescriptions are discussed in terms of their potential physical origins, which might include dynamical perturbations from a low-mass companion with an orbital separation of a few AU.

  2. Chasing Shadows: Rotation of the Azimuthal Asymmetry in the TW Hya Disk

    Science.gov (United States)

    Debes, John H.; Poteet, Charles A.; Jang-Condell, Hannah; Gaspar, Andras; Hines, Dean; Kastner, Joel H.; Pueyo, Laurent; Rapson, Valerie; Roberge, Aki; Schneider, Glenn; Weinberger, Alycia J.

    2017-02-01

    We have obtained new images of the protoplanetary disk orbiting TW Hya in visible, total intensity light with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST), using the newly commissioned BAR5 occulter. These HST/STIS observations achieved an inner working angle of ∼0.″2, or 11.7 au, probing the system at angular radii coincident with recent images of the disk obtained by ALMA and in polarized intensity near-infrared light. By comparing our new STIS images to those taken with STIS in 2000 and with NICMOS in 1998, 2004, and 2005, we demonstrate that TW Hya’s azimuthal surface brightness asymmetry moves coherently in position angle. Between 50 au and 141 au we measure a constant angular velocity in the azimuthal brightness asymmetry of 22.°7 yr‑1 in a counterclockwise direction, equivalent to a period of 15.9 yr assuming circular motion. Both the (short) inferred period and lack of radial dependence of the moving shadow pattern are inconsistent with Keplerian rotation at these disk radii. We hypothesize that the asymmetry arises from the fact that the disk interior to 1 au is inclined and precessing owing to a planetary companion, thus partially shadowing the outer disk. Further monitoring of this and other shadows on protoplanetary disks potentially opens a new avenue for indirectly observing the sites of planet formation. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  3. HYDRA-II: A hydrothermal analysis computer code: Volume 3, Verification/validation assessments

    Energy Technology Data Exchange (ETDEWEB)

    McCann, R.A.; Lowery, P.S.

    1987-10-01

    HYDRA-II is a hydrothermal computer code capable of three-dimensional analysis of coupled conduction, convection, and thermal radiation problems. This code is especially appropriate for simulating the steady-state performance of spent fuel storage systems. The code has been evaluated for this application for the US Department of Energy's Commercial Spent Fuel Management Program. HYDRA-II provides a finite difference solution in cartesian coordinates to the equations governing the conservation of mass, momentum, and energy. A cylindrical coordinate system may also be used to enclose the cartesian coordinate system. This exterior coordinate system is useful for modeling cylindrical cask bodies. The difference equations for conservation of momentum are enhanced by the incorporation of directional porosities and permeabilities that aid in modeling solid structures whose dimensions may be smaller than the computational mesh. The equation for conservation of energy permits modeling of orthotropic physical properties and film resistances. Several automated procedures are available to model radiation transfer within enclosures and from fuel rod to fuel rod. The documentation of HYDRA-II is presented in three separate volumes. Volume I - Equations and Numerics describes the basic differential equations, illustrates how the difference equations are formulated, and gives the solution procedures employed. Volume II - User's Manual contains code flow charts, discusses the code structure, provides detailed instructions for preparing an input file, and illustrates the operation of the code by means of a model problem. This volume, Volume III - Verification/Validation Assessments, provides a comparison between the analytical solution and the numerical simulation for problems with a known solution. This volume also documents comparisons between the results of simulations of single- and multiassembly storage systems and actual experimental data. 11 refs., 55 figs., 13 tabs.

  4. HYDRA-II: A hydrothermal analysis computer code: Volume 2, User's manual

    Energy Technology Data Exchange (ETDEWEB)

    McCann, R.A.; Lowery, P.S.; Lessor, D.L.

    1987-09-01

    HYDRA-II is a hydrothermal computer code capable of three-dimensional analysis of coupled conduction, convection, and thermal radiation problems. This code is especially appropriate for simulating the steady-state performance of spent fuel storage systems. The code has been evaluated for this application for the US Department of Energy's Commercial Spent Fuel Management Program. HYDRA-II provides a finite-difference solution in cartesian coordinates to the equations governing the conservation of mass, momentum, and energy. A cylindrical coordinate system may also be used to enclose the cartesian coordinate system. This exterior coordinate system is useful for modeling cylindrical cask bodies. The difference equations for conservation of momentum incorporate directional porosities and permeabilities that are available to model solid structures whose dimensions may be smaller than the computational mesh. The equation for conservation of energy permits modeling of orthotropic physical properties and film resistances. Several automated methods are available to model radiation transfer within enclosures and from fuel rod to fuel rod. The documentation of HYDRA-II is presented in three separate volumes. Volume 1 - Equations and Numerics describes the basic differential equations, illustrates how the difference equations are formulated, and gives the solution procedures employed. This volume, Volume 2 - User's Manual, contains code flow charts, discusses the code structure, provides detailed instructions for preparing an input file, and illustrates the operation of the code by means of a sample problem. The final volume, Volume 3 - Verification/Validation Assessments, provides a comparison between the analytical solution and the numerical simulation for problems with a known solution. 6 refs.

  5. Central mass profiles of the nearby cool-core galaxy clusters Hydra A and A478

    Science.gov (United States)

    Okabe, N.; Umetsu, K.; Tamura, T.; Fujita, Y.; Takizawa, M.; Matsushita, K.; Fukazawa, Y.; Futamase, T.; Kawaharada, M.; Miyazaki, S.; Mochizuki, Y.; Nakazawa, K.; Ohashi, T.; Ota, N.; Sasaki, T.; Sato, K.; Tam, S. I.

    2016-03-01

    We perform a weak-lensing study of the nearby cool-core galaxy clusters, Hydra A (z = 0.0538) and A478 (z = 0.0881), of which the brightest cluster galaxies (BCGs) host the powerful activities of active galactic nuclei (AGNs). For each cluster, the observed tangential shear profile is described well by either a single Navarro-Frenk-White model or a two-component model including the BCG as an unresolved point mass. For A478, we determine the BCG and its host-halo masses from a joint fit to weak-lensing and stellar photometry measurements. We find that the choice of initial mass functions (IMFs) can introduce a factor of 2 uncertainty in the BCG mass, whereas the BCG host-halo mass is constrained well by data. We perform a joint analysis of the weak-lensing and stellar kinematics data available for the Hydra A cluster, which allows us to constrain the central mass profile without assuming specific IMFs. We find that the central mass profile (r < 300 kpc) determined from the joint analysis is in excellent agreement with those from independent measurements, including dynamical masses estimated from the cold gas disc component, X-ray hydrostatic total mass estimates, and the central stellar mass estimated with the Salpeter IMF. The observed dark matter fraction around the BCG for Hydra A is found to be smaller than those predicted by adiabatic contraction models, suggesting the importance of other physical processes, such as AGN feedback and/or dissipationless mergers.

  6. Hydra: A web-based system for cardiovascular analysis, diagnosis and treatment.

    Science.gov (United States)

    Novo, J; Hermida, A; Ortega, M; Barreira, N; Penedo, M G; López, J E; Calvo, C

    2017-02-01

    Cardiovascular (CV) risk stratification is a highly complex process involving an extensive set of clinical trials to support the clinical decision-making process. There are many clinical conditions (e.g. diabetes, obesity, stress, etc.) that can lead to the early diagnosis or establishment of cardiovascular disease. In order to determine all these clinical conditions, a complete set of clinical patient analyses is typically performed, including a physical examination, blood analysis, electrocardiogram, blood pressure (BP) analysis, etc. This article presents a web-based system, called Hydra, which integrates a full and detailed set of services and functionalities for clinical decision support in order to help and improve the work of clinicians in cardiovascular patient diagnosis, risk assessment, treatment and monitoring over time. Hydra integrates a number of different services: a service for inputting all the information gathered by specialists (physical examination, habits, BP, blood analysis, electrocardiogram, etc.); a tool to automatically determine the CV risk stratification, including well-known standard risk stratification tables; and, finally, various tools to incorporate, analyze and graphically present the records of the ambulatory BP monitoring that provides BP analysis over a given period of time (24 or 48 hours). In addition, the platform presents a set of reports derived from all the information gathered from the patient in order to support physicians in their clinical decisions. Hydra was tested and validated in a real domain. In particular, internal medicine specialists at the Hypertension Unit of the Santiago de Compostela University Hospital (CHUS) validated the platform and used it in different clinical studies to demonstrate its utility. It was observed that the platform increased productivity and accuracy in the assessment of patient data yielding a cost reduction in clinical practice. This paper proposes a complete platform that includes

  7. Advances in HYDRA and its applications to simulations of inertial confinement fusion targets

    Directory of Open Access Journals (Sweden)

    Marinak M.M.

    2013-11-01

    Full Text Available A new set of capabilities has been implemented in the HYDRA 2D/3D multiphysics inertial confinement fusion simulation code. These include a Monte Carlo particle transport library. It models transport of neutrons, gamma rays and light ions, as well as products they generate from nuclear and coulomb collisions. It allows accurate simulations of nuclear diagnostic signatures from capsule implosions. We apply it to here in a 3D simulation of a National Ignition Facility (NIF ignition capsule which models the full capsule solid angle. This simulation contains a severely rough ablator perturbation and provides diagnostics signatures of capsule failure due to excessive instability growth.

  8. A Polar Discrete Ordinate Radiation Transport Method for 2D ALE Meshes in HYDRA

    Science.gov (United States)

    Chang, Britton; Marinak, Marty; Weber, Chris; Peterson, Luc

    2016-10-01

    The Polar Discrete Ordinate Radiation Transport Method in HYDRA has been extended to handle general 2D r-z meshes. Previously the method was only for orthogonal 2D meshes. The new method can be employed with the ALE methodology for managing mesh motion that is used to simulate Rayleigh-Taylor and Richtmyer-Meshkov instabilities on NIF capsule implosions. The results of an examination of this kind will be compared to those obtained by the corresponding diffusion method. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

  9. A novel gene family controls species-specific morphological traits in Hydra.

    Directory of Open Access Journals (Sweden)

    Konstantin Khalturin

    2008-11-01

    Full Text Available Understanding the molecular events that underlie the evolution of morphological diversity is a major challenge in biology. Here, to identify genes whose expression correlates with species-specific morphologies, we compared transcriptomes of two closely related Hydra species. We find that species-specific differences in tentacle formation correlate with expression of a taxonomically restricted gene encoding a small secreted protein. We show that gain of function induces changes in morphology that mirror the phenotypic differences observed between species. These results suggest that "novel" genes may be involved in the generation of species-specific morphological traits.

  10. A fragmented metazoan organellar genome: the two mitochondrial chromosomes of Hydra magnipapillata

    Directory of Open Access Journals (Sweden)

    Wörheide Gert

    2008-07-01

    Full Text Available Abstract Background Animal mitochondrial (mt genomes are characteristically circular molecules of ~16–20 kb. Medusozoa (Cnidaria excluding Anthozoa are exceptional in that their mt genomes are linear and sometimes subdivided into two to presumably four different molecules. In the genus Hydra, the mt genome comprises one or two mt chromosomes. Here, we present the whole mt genome sequence from the hydrozoan Hydra magnipapillata, comprising the first sequence of a fragmented metazoan mt genome encoded on two linear mt chromosomes (mt1 and mt2. Results The H. magnipapillata mt chromosomes contain the typical metazoan set of 13 genes for respiratory proteins, the two rRNA genes and two tRNA genes. All genes are unidirectionally oriented on mt1 and mt2, and several genes overlap. The gene arrangement suggests that the two mt chromosomes originated from one linear molecule that separated between nd5 and rns. Strong correlations between the AT content of rRNA genes (rns and rnl and the AT content of protein-coding genes among 24 cnidarian genomes imply that base composition is mainly determined by mt genome-wide constraints. We show that identical inverted terminal repeats (ITR occur on both chromosomes; these ITR contain a partial copy or part of the 3' end of cox1 (54 bp. Additionally, both mt chromosomes possess identical oriented sequences (IOS at the 5' and 3' ends (5' and 3' IOS adjacent to the ITR. The 5' IOS contains trnM and non-coding sequences (119 bp, whereas the 3' IOS comprises a larger part (mt2 with a larger partial copy of cox1 (243 bp. Conclusion ITR are also documented in the two other available medusozoan mt genomes (Aurelia aurita and Hydra oligactis. In H. magnipapillata, the arrangement of ITR and 5' IOS and 3' IOS suggest that these regions are crucial for mt DNA replication and/or transcription initiation. An analogous organization occurs in a highly fragmented ichthyosporean mt genome. With our data, we can reject a model of

  11. The putative Notch ligand HyJagged is a transmembrane protein present in all cell types of adult Hydra and upregulated at the boundary between bud and parent

    Directory of Open Access Journals (Sweden)

    Tischer Susanne

    2011-09-01

    Full Text Available Abstract Background The Notch signalling pathway is conserved in pre-bilaterian animals. In the Cnidarian Hydra it is involved in interstitial stem cell differentiation and in boundary formation during budding. Experimental evidence suggests that in Hydra Notch is activated by presenilin through proteolytic cleavage at the S3 site as in all animals. However, the endogenous ligand for HvNotch has not been described yet. Results We have cloned a cDNA from Hydra, which encodes a bona-fide Notch ligand with a conserved domain structure similar to that of Jagged-like Notch ligands from other animals. Hyjagged mRNA is undetectable in adult Hydra by in situ hybridisation but is strongly upregulated and easily visible at the border between bud and parent shortly before bud detachment. In contrast, HyJagged protein is found in all cell types of an adult hydra, where it localises to membranes and endosomes. Co-localisation experiments showed that it is present in the same cells as HvNotch, however not always in the same membrane structures. Conclusions The putative Notch ligand HyJagged is conserved in Cnidarians. Together with HvNotch it may be involved in the formation of the parent-bud boundary in Hydra. Moreover, protein distribution of both, HvNotch receptor and HyJagged indicate a more widespread function for these two transmembrane proteins in the adult hydra, which may be regulated by additional factors, possibly involving endocytic pathways.

  12. Single top-quark production via $tW$, $tZq$, and $s$-channel with ATLAS and CMS

    CERN Document Server

    Finelli, Kevin Daniel; The ATLAS collaboration

    2017-01-01

    Analyses of single top-quark production in the $s$-channel, via $tW$ production, and via $tZq$ production are presented, showing the scope of recent ATLAS and CMS analysis of LHC data. Cross-section values and signal significance estimates are established, confirming good agreement with the most precise available fixed-order calculations for each production mode.

  13. Potential aquaculture probiont Lactococcus lactis TW34 produces nisin Z and inhibits the fish pathogen Lactococcus garvieae.

    Science.gov (United States)

    Sequeiros, Cynthia; Garcés, Marisa E; Vallejo, Marisol; Marguet, Emilio R; Olivera, Nelda L

    2015-04-01

    Bacteriocin-producing Lactococcus lactis TW34 was isolated from marine fish. TW34 bacteriocin inhibited the growth of the fish pathogen Lactococcus garvieae at 5 AU/ml (minimum inhibitory concentration), whereas the minimum bactericidal concentration was 10 AU/ml. Addition of TW34 bacteriocin to L. garvieae cultures resulted in a decrease of six orders of magnitude of viable cells counts demonstrating a bactericidal mode of action. The direct detection of the bacteriocin activity by Tricine-SDS-PAGE showed an active peptide with a molecular mass ca. 4.5 kDa. The analysis by MALDI-TOF-MS detected a strong signal at m/z 2,351.2 that corresponded to the nisin leader peptide mass without the initiating methionine, whose sequence STKDFNLDLVSVSKKDSGASPR was confirmed by MS/MS. Sequence analysis of nisin structural gene confirmed that L. lactis TW34 was a nisin Z producer. This nisin Z-producing strain with probiotic properties might be considered as an alternative in the prevention of lactococcosis, a global disease in aquaculture systems.

  14. Molecular cloning of a preprohormone from Hydra magnipapillata containing multiple copies of Hydra-L Wamide (Leu-Trp-NH2) neuropeptides: evidence for processing at Ser and Asn residues

    DEFF Research Database (Denmark)

    Leviev, I; Williamson, M; Grimmelikhuijzen, C J

    1997-01-01

    The simple, freshwater polyp Hydra is often used as a model to study development in cnidarians. Recently, a neuropeptide, < Glu-Gln-Pro-Gly-Leu-Trp-NH2, has been isolated from sea anemones that induces metamorphosis in a hydroid planula larva to become a polyp. Here, we have cloned a preprohormon...

  15. Lunar-based Ultraviolet Telescope study of the well-known Algol-type binary TW Dra

    Science.gov (United States)

    Liao, Wen-Ping; Qian, Sheng-Bang; Zejda, Miloslav; Zhu, Li-Ying; Li, Lin-Jia

    2016-06-01

    By using the Lunar-based Ultraviolet Telescope (LUT) from 2014 December 2 to December 4, the first near-UV light curve of the well-known Algol-type binary TW Dra is reported, which is analyzed with the 2013 version of the W-D code. Our solutions confirmed that TW Dra is a semi-detached binary system where the secondary component fills its Roche lobe. The mass ratio and a high inclination are obtained (q = 0.47, i = 86.68°). Based on 589 available data spanning more than one century, the complex period changes are studied. Secular increase and three cyclical changes are found in the corresponding orbital period analysis. The secular increase changes reveal mass transfer from the secondary component to the primary one at a rate of 6.8 × 10-7 M ⊙ yr-1. One large cyclical change of 116.04 yr may be caused by disturbance of visual component ADS 9706B orbiting TW Dra (ADS 9706A), while the other two cyclical changes with shorter periods of 22.47 and 37.27 yr can be explained as the result of two circumbinary companions that are orbiting around TW Dra, where the two companions are in simple 3 : 5 orbit-rotation resonances. TW Dra itself is a basic binary in a possible sextuple system with the configuration (1 + 1) + (1 + 1) + (1 + 1), which further suggests that multiplicity may be a fairly common phenomenon in close binary systems.

  16. High-resolution 3D simulations of NIF ignition targets performed on Sequoia with HYDRA

    Science.gov (United States)

    Marinak, M. M.; Clark, D. S.; Jones, O. S.; Kerbel, G. D.; Sepke, S.; Patel, M. V.; Koning, J. M.; Schroeder, C. R.

    2015-11-01

    Developments in the multiphysics ICF code HYDRA enable it to perform large-scale simulations on the Sequoia machine at LLNL. With an aggregate computing power of 20 Petaflops, Sequoia offers an unprecedented capability to resolve the physical processes in NIF ignition targets for a more complete, consistent treatment of the sources of asymmetry. We describe modifications to HYDRA that enable it to scale to over one million processes on Sequoia. These include new options for replicating parts of the mesh over a subset of the processes, to avoid strong scaling limits. We consider results from a 3D full ignition capsule-only simulation performed using over one billion zones run on 262,000 processors which resolves surface perturbations through modes l = 200. We also report progress towards a high-resolution 3D integrated hohlraum simulation performed using 262,000 processors which resolves surface perturbations on the ignition capsule through modes l = 70. These aim for the most complete calculations yet of the interactions and overall impact of the various sources of asymmetry for NIF ignition targets. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

  17. Validity of HydraTrend reagent strips for the assessment of hydration status.

    Science.gov (United States)

    Abbey, Bryce M; Heelan, Kate A; Brown, Gregory A; Bartee, Rodrick T

    2014-09-01

    Hydration is used by athletic governing organizations for weight class eligibility. The measurement of urine specific gravity (USG) as a measure of hydration by reagent strips is a controversial issue. The purpose of this study was to determine the validity of HydraTrend reagent strips that facilitate the correction of USG for alkaline urine samples against refractometry for the assessment of USG. Fifty-one participants (33 males, age = 22.3 ± 1.3 years; 18 females, age = 22.4 ± 1.2 years) provided 84 urine samples. The samples were tested for USG using refractometry and reagent strips and for pH using reagent strips and a digital pH meter. Strong correlation coefficients were found between refractometry and reagent strips for USG (rs(82) = 0.812, p refractometry with USG >1.020, pass reagent strips with USG ≤1.020) occurred 39% (33/84) of the time and false negative results for National Federation of State High School Association (NFHS) requirements (fail refractometry with USG >1.025, pass reagent strips with USG ≤1.025) occurred 14% (12/84) of the time. There were no false positives (pass refractometry and fail reagent strips) for NCAA or NFHS requirements. These data show that refractometry and reagent strips have strong positive correlations. However, the risk of a false negative result leading to incorrect certification of euhydration status outweighs the benefits of the HydraTrend reagent strips for the measurement of USG.

  18. Mutagenesis and functional analysis of the pore-forming toxin HALT-1 from Hydra magnipapillata.

    Science.gov (United States)

    Liew, Yvonne Jing Mei; Soh, Wai Tuck; Jiemy, William Febry; Hwang, Jung Shan

    2015-02-03

    Actinoporins are small 18.5 kDa pore-forming toxins. A family of six actinoporin genes has been identified in the genome of Hydra magnipapillata, and HALT-1 (Hydra actinoporin-like toxin-1) has been shown to have haemolytic activity. In this study, we have used site-directed mutagenesis to investigate the role of amino acids in the pore-forming N-terminal region and the conserved aromatic cluster required for cell membrane binding. A total of 10 mutants of HALT-1 were constructed and tested for their haemolytic and cytolytic activity on human erythrocytes and HeLa cells, respectively. Insertion of 1-4 negatively charged residues in the N-terminal region of HALT-1 strongly reduced haemolytic and cytolytic activity, suggesting that the length or charge of the N-terminal region is critical for pore-forming activity. Moreover, substitution of amino acids in the conserved aromatic cluster reduced haemolytic and cytolytic activity by more than 80%, suggesting that these aromatic amino acids are important for attachment to the lipid membrane as shown for other actinoporins. The results suggest that HALT-1 and other actinoporins share similar mechanisms of pore formation and that it is critical for HALT-1 to maintain an amphipathic helix at the N-terminus and an aromatic amino acid-rich segment at the site of membrane binding.

  19. Mutagenesis and Functional Analysis of the Pore-Forming Toxin HALT-1 from Hydra magnipapillata

    Directory of Open Access Journals (Sweden)

    Yvonne Jing Mei Liew

    2015-02-01

    Full Text Available Actinoporins are small 18.5 kDa pore-forming toxins. A family of six actinoporin genes has been identified in the genome of Hydra magnipapillata, and HALT-1 (Hydra actinoporin-like toxin-1 has been shown to have haemolytic activity. In this study, we have used site-directed mutagenesis to investigate the role of amino acids in the pore-forming N-terminal region and the conserved aromatic cluster required for cell membrane binding. A total of 10 mutants of HALT-1 were constructed and tested for their haemolytic and cytolytic activity on human erythrocytes and HeLa cells, respectively. Insertion of 1–4 negatively charged residues in the N-terminal region of HALT-1 strongly reduced haemolytic and cytolytic activity, suggesting that the length or charge of the N-terminal region is critical for pore-forming activity. Moreover, substitution of amino acids in the conserved aromatic cluster reduced haemolytic and cytolytic activity by more than 80%, suggesting that these aromatic amino acids are important for attachment to the lipid membrane as shown for other actinoporins. The results suggest that HALT-1 and other actinoporins share similar mechanisms of pore formation and that it is critical for HALT-1 to maintain an amphipathic helix at the N-terminus and an aromatic amino acid-rich segment at the site of membrane binding.

  20. Dickkopf related genes are components of the positional value gradient in Hydra.

    Science.gov (United States)

    Augustin, René; Franke, André; Khalturin, Konstantin; Kiko, Rainer; Siebert, Stefan; Hemmrich, Georg; Bosch, Thomas C G

    2006-08-01

    Hydra is a classical model organism to understand fundamental developmental biological processes such as regeneration and axis formation. Here, we show that two genes which share some similarity with members of the Dickkopf family of proteins, HyDkk1/2/4-A and HyDkk1/2/4-C, are co-expressed in gland cells and regulated by the positional value gradient. While HyDkk1/2/4-A is expressed throughout the gastric region, HyDkk1/2/4-C has a graded expression pattern with a high level of transcripts just below the tentacle zone and absence of expression in the budding zone. Blocking the activity of GSK-3beta caused a drastic downregulation of HyDkk1/2/4-C expression in the gastric tissue. Experimental reduction of the number of HyDkk1/2/4-C-expressing cells resulted in expansion of the HyWnt expression domain in the hypostome. Thus, similar to Dickkopf proteins in vertebrates, one of the functions of HyDkk1/2/4-C in hydra may be to antagonize Wnt signalling.

  1. Central Mass Profiles of the Nearby Cool-core Galaxy Clusters Hydra A and A478

    CERN Document Server

    Okabe, N; Tamura, T; Fujita, Y; Takizawa, M; Matsushita, K; Fukazawa, Y; Futamase, T; Kawaharada, M; Miyazaki, S; Mochizuki, Y; Nakazawa, K; Ohashi, T; Ota, N; Sasaki, T; Sato, K; Tam, S I

    2015-01-01

    We perform a weak-lensing study of the nearby cool-core galaxy clusters, Hydra A ($z=0.0538$) and A478 ($z=0.0881$), of which brightest cluster galaxies (BCGs) host powerful activities of active galactic nuclei (AGNs). For each cluster, the observed tangential shear profile is well described either by a single Navarro--Frenk--White model or a two-component model including the BCG as an unresolved point mass. For A478, we determine the BCG and its host-halo masses from a joint fit to weak-lensing and stellar photometry measurements. We find that the choice of initial mass functions (IMFs) can introduce a factor of two uncertainty in the BCG mass, whereas the BCG host halo mass is well constrained by data. We perform a joint analysis of weak-lensing and stellar kinematics data available for the Hydra A cluster, which allows us to constrain the central mass profile without assuming specific IMFs.We find that the central mass profile ($r<300$ kpc) determined from the joint analysis is in excellent agreement wi...

  2. Analysis of vascular development in the hydra sterol biosynthetic mutants of Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Margaret Pullen

    Full Text Available The control of vascular tissue development in plants is influenced by diverse hormonal signals, but their interactions during this process are not well understood. Wild-type sterol profiles are essential for growth, tissue patterning and signalling processes in plant development, and are required for regulated vascular patterning.Here we investigate the roles of sterols in vascular tissue development, through an analysis of the Arabidopsis mutants hydra1 and fackel/hydra2, which are defective in the enzymes sterol isomerase and sterol C-14 reductase respectively. We show that defective vascular patterning in the shoot is associated with ectopic cell divisions. Expression of the auxin-regulated AtHB8 homeobox gene is disrupted in mutant embryos and seedlings, associated with variably incomplete vascular strand formation and duplication of the longitudinal axis. Misexpression of the auxin reporter proIAA2ratioGUS and mislocalization of PIN proteins occurs in the mutants. Introduction of the ethylene-insensitive ein2 mutation partially rescues defective cell division, localization of PIN proteins, and vascular strand development.The results support a model in which sterols are required for correct auxin and ethylene crosstalk to regulate PIN localization, auxin distribution and AtHB8 expression, necessary for correct vascular development.

  3. Different Endosymbiotic Interactions in Two Hydra Species Reflect the Evolutionary History of Endosymbiosis

    KAUST Repository

    Ishikawa, Masakazu

    2016-06-19

    Endosymbiosis is an important evolutionary event for organisms, and there is widespread interest in understanding the evolution of endosymbiosis establishment. Hydra is one of the most suitable organisms for studying the evolution of endosymbiosis. Within the genus Hydra, H. viridissima and H. vulgaris show endosymbiosis with green algae. Previous studies suggested that the endosymbiosis in H. vulgaris took place much more recently than that in H. viridissima, noting that the establishment of the interaction between H. vulgaris and its algae is not as stable as in H. viridissima. To investigate the on-going process of endosymbiosis, we first compared growth and tolerance to starvation in symbiotic and aposymbiotic polyps of both species. The results revealed that symbiotic H. viridissima had a higher growth rate and greater tolerance to starvation than aposymbiotic polyps. By contrast, growth of symbiotic H. vulgaris was identical to that of aposymbiotic polyps, and symbiotic H. vulgaris was less tolerant to starvation. Moreover, our gene expression analysis showed a pattern of differential gene expression in H. viridissima similar to that in other endosymbiotically established organisms, and contrary to that observed in H. vulgaris. We also showed that H. viridissima could cope with oxidative stress that caused damage, such as cell death, in H. vulgaris. These observations support the idea that oxidative stress related genes play an important role in the on-going process of endosymbiosis evolution. The different evolutionary stages of endosymbiosis studied here provide a deeper insight into the evolutionary processes occurring toward a stable endosymbiosis.

  4. Direct Evidence for Outflow of Metal-enriched Gas Along the Radio Jets of Hydra A

    CERN Document Server

    Kirkpatrick, C C; Cavagnolo, K W; McNamara, B R; David, L P; Nulsen, P E J; Wise, M W

    2009-01-01

    Using deep Chandra observations of the Hydra A galaxy cluster, we examine the metallicity structure near the central galaxy and along its powerful radio source. We show that the metallicity of the intracluster medium is enhanced by up to 0.2 dex along the radio jets and lobes compared to the metallicity of the undisturbed gas. The enhancements extend from a radius of 20 kpc from the central galaxy to a distance of ~ 120 kpc. We estimate the total iron mass that has been transported out of the central galaxy to be between 2 x 10^7 M_sun and 7 x 10^7 M_sun which represents 10% - 20% of the iron mass within the central galaxy. The energy required to lift this gas is roughly 1% to 5% of the total energetic output of the AGN. Evidently, Hydra A's powerful radio source is able to redistribute metal-enriched, low entropy gas throughout the core of the galaxy cluster. The short re-enrichment time scale < 10^9 yr implies that the metals lost from the central galaxy will be quickly replenished.

  5. Jet-Intracluster Medium interaction in Hydra A. I Estimates of jet velocity from inner knots

    CERN Document Server

    Nawaz, M A; Bicknell, G V; Sutherland, R S; McNamara, B R

    2014-01-01

    We present the first stage of an investigation of the interactions of the jets in the radio galaxy Hydra A with the intracluster medium. We consider the jet kinetic power, the galaxy and cluster atmosphere, and the inner structure of the radio source. Analysing radio observations of the inner lobes of Hydra A by Taylor et al. (1990) we confirm the jet power estimates of about 1e45 ergs/s derived by Wise et al. (2007) from dynamical analysis of the X-ray cavities. With this result and a model for the galaxy halo, we explore the jet-intracluster medium interactions occurring on a scale of 10 kpc using two-dimensional, axisymmetric, relativistic pure hydrodynamic simulations. A key feature is that we identify the three bright knots in the northern jet as biconical reconfinement shocks, which result when an over pressured jet starts to come into equilibrium with the galactic atmosphere. Through an extensive parameter space study we deduce that the jet velocity is approximately 0.8 c at a distance 0.5 kpc from the...

  6. Testing the cooling flow model in the intermediate polar EX Hydrae

    CERN Document Server

    Luna, G J M; Brickhouse, N S; Mauche, C W; Suleimanov, V; .,

    2015-01-01

    We use the best available X-ray data from the intermediate polar EX Hydrae to study the cooling-flow model often applied to interpret the X-ray spectra of these accreting magnetic white dwarf binaries. First, we resolve a long-standing discrepancy between the X-ray and optical determinations of the mass of the white dwarf in EX Hya by applying new models of the inner disk truncation radius. Our fits to the X-ray spectrum now agree with the white dwarf mass of 0.79 M$_{\\odot}$sun determined using dynamical methods through spectroscopic observations of the secondary. We use a simple isobaric cooling flow model to derive the emission line fluxes, emission measure distribution, and H-like to He-like line ratios for comparison with the 496 ks Chandra High Energy Transmission Grating observation of EX Hydrae. We find that the H/He ratios are not well reproduced by this simple isobaric cooling flow model and show that while H-like line fluxes can be accurately predicted, fluxes of lower-Z He-like lines are significa...

  7. The Super Gaussian Laser Intensity Profile in HYDRA's 3D Laser Ray Trace Package

    Energy Technology Data Exchange (ETDEWEB)

    Sepke, Scott M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-01-05

    In this note, the laser focal plane intensity pro le for a beam modeled using the 3D ray trace package in HYDRA is determined. First, the analytical model is developed followed by a practical numerical model for evaluating the resulting computationally intensive normalization factor for all possible input parameters.

  8. Ultrastructural localization of RFamide-like peptides in neuronal dense-cored vesicles in the peduncle of Hydra

    DEFF Research Database (Denmark)

    Koizumi, O; Wilson, Douglas Clyde; Grimmelikhuijzen, C J

    1989-01-01

    The presence of Arg-Phe-amide (RFamide)-like peptides in dense-cored vesicles in neurons of the peduncle of Hydra was demonstrated by immunogold electron microscopy. Thin sections of Lowicryl-embedded tissue labeled with antisera to RFamide and 5-nm gold-conjugated, secondary antibody and of Epon...

  9. A new species of hydra (Cnidaria: Hydrozoa: Hydridae) and molecular phylogenetic analysis of six congeners from China.

    Science.gov (United States)

    Wang, An-Tai; Deng, Li; Liu, Hong-Tao

    2012-12-01

    A new species of genus Hydra (Cnidaria: Hydrozoa: Hydridae), Hydra shenzhensis sp. nov. from Guangdong Province, China, is described and illustrated. Most polyps have five tentacles. Column length reaches 11 mm when relaxed. Buds do not acquire tentacles synchronously. Stenotele is broad and pyriform in shape, 1.2 times as long as its width. Holotrichous isorhiza is asymmetrical and slender (more than 2.7 times as long as its width), with transverse and slanting coils. Atrichous isorhiza is long, resembling a melon-seed in shape. Desmoneme is asymmetrically pyriform in shape. The new species, belonging to the vulgaris group, is dioecious; sexual reproduction was found to occur mostly during November and December under conditions of dense culture or food shortage. Two to thirteen testes, cone-like shape with papilla, formed beneath the tentacles. One to three ovaries, with an egg cup, milky white in color, formed on body column. Ninety percent of individuals developed only one ovum. On a mother polyp, a fertilized ovum developed an embryonic theca covering its surface. The embryotheca is brown, with a spine-like structure, covering a layer of transparent, membrane-like material. For phylogenetic analysis, the mitochondrial cytochrome oxidase subunit I gene (COI) of six hydra species collected from China was amplified by polymerase chain reaction (PCR) and sequenced. Morphological characters in combination with molecular evidence support the hydra described here as a new species.

  10. Hydra II: A Faint and Compact Milky Way Dwarf Galaxy Found in the Survey of the Magellanic Stellar History

    NARCIS (Netherlands)

    Martin, Nicolas F.; Nidever, David L.; Besla, Gurtina; Olsen, Knut; Walker, Alistair R.; Vivas, A. Katherina; Gruendl, Robert A.; Kaleida, Catherine C.; Muñoz, Ricardo R.; Blum, Robert D.; Saha, Abhijit; Conn, Blair C.; Bell, Eric F.; Chu, You-Hua; Cioni, Maria-Rosa L.; de Boer, Thomas J. L.; Gallart, Carme; Jin, Shoko; Kunder, Andrea; Majewski, Steven R.; Martinez-Delgado, David; Monachesi, Antonela; Monelli, Matteo; Monteagudo, Lara; Noël, Noelia E. D.; Olszewski, Edward W.; Stringfellow, Guy S.; van der Marel, Roeland P.; Zaritsky, Dennis

    We present the discovery of a new dwarf galaxy, Hydra II, found serendipitously within the data from the ongoing Survey of the Magellanic Stellar History conducted with the Dark Energy Camera on the Blanco 4 m Telescope. The new satellite is compact ({{r}h}=68 ± 11 pc) and faint ({{M}V}=-4.8 ± 0.3),

  11. X-Ray Supercavities in the Hydra A Cluster and the Outburst History of the Central Galaxy's Active Nucleus

    NARCIS (Netherlands)

    Wise, M.; McNamara, B.R.; Nulsen, P.E.J.; Houck, J.C.; David, L.P.

    2007-01-01

    A 227 ks Chandra X-ray image of the hot plasma in the Hydra A cluster has revealed an extensive cavity system. The system was created by a continuous outflow or a series of bursts from the nucleus of the central galaxy over the past 200-500 Myr. The cavities have displaced 10% of the plasma within a

  12. The identity and occurrence of Kerona pediculus (Ciliophora: Hypotrichida), a well-known epizoite of Hydra vulgaris (Cnidaria: Hydrozoa)

    NARCIS (Netherlands)

    Warren, A.; Robson, E.A.

    1998-01-01

    Epizoic Kerona pediculus have been found on Hydra vulgaris and on Cristatella mucedo (Bryozoa) in the same habitat. On the basis of morphological characters (using Nomarski and Scanning Electron Microscopy) specimens from the two hosts are indistinguishable. Details revealed by SEM agree with

  13. Hydra phantom applicability for carrying out tests of field uniformity in gamma cameras; Aplicabilidade do fantoma hydra para realizacao dos testes de uniformidade de campo em gama camaras

    Energy Technology Data Exchange (ETDEWEB)

    Aragao Filho, Geraldo L., E-mail: geraldo_lemos10@hotmail.com [Centro de Medicina Nuclear de Pernambuco (CEMUPE), Recife, PE (Brazil); Oliveira, Alex C.H., E-mail: oliveira_ach@yahoo.com [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Lopes Filho, Ferdinand J.; Vieira, Jose W., E-mail: ferdinand.lopes@oi.com.br, E-mail: jose-wilson59@live.com [Instituto Federal de Pernambuco (IFPE), Recife, PE (Brazil)

    2014-07-01

    Nuclear Medicine is a medical modality that makes use of radioactive material 'in vivo' in humans, making them a temporary radioactive source. The radiation emitted by the patient's body is detected by a specific equipment, called a gamma camera, creates an image showing the spatial and temporal biodistribution of radioactive material administered to the patient. Therefore, it's of fundamental importance a number of specific measures to make sure that procedure be satisfactory, called quality control. To Nuclear Medicine, quality control of gamma camera has the purpose of ensuring accurate scintillographic imaging, truthful and reliable for the diagnosis, guaranteeing visibility and clarity of details of structures, and also to determine the frequency and the need for preventive maintenance of equipment. To ensure the quality control of the gamma camera it's necessary to use some simulators, called phantom, used in Nuclear Medicine to evaluate system performance, system calibration and simulation of injuries. The goal of this study was to validate a new simulator for nuclear medicine, the Hydra phantom. The phantom was initially built for construction of calibration curves used in radiotherapy planning and quality control in CT. It has similar characteristics to specific phantoms in nuclear medicine, containing inserts and water area. Those inserts are regionally sourced materials, many of them are already used in the literature and based on information about density and interaction of radiation with matter. To verify its efficiency in quality control in Nuclear Medicine, was performed a test for uniformity field, one of the main tests performed daily, so we can verify the ability of the gamma camera to reproduce a uniform distribution of the administered activity in the phantom, been analysed qualitatively, through the image, and quantitatively, through values established for Central Field Of View (CFOV) and Useful Field Of View (UFOV

  14. Volatile carbon locking and release in protoplanetary disks. A study of TW Hya and HD 100546

    CERN Document Server

    Kama, M; van Dishoeck, E F; Hogerheijde, M; Folsom, C P; Miotello, A; Fedele, D; Belloche, A; Güsten, R; Wyrowski, F

    2016-01-01

    The composition of planetary solids and gases is largely rooted in the processing of volatile elements in protoplanetary disks. To shed light on the key processes, we carry out a comparative analysis of the gas-phase carbon abundance in two systems with a similar age and disk mass, but different central stars: HD 100546 and TW Hya. We combine our recent detections of C$^{0}$ in these disks with observations of other carbon reservoirs (CO, C$^{+}$, C$_{2}$H) and gas mass and warm gas tracers (HD, O$^{0}$), as well as spatially resolved ALMA observations and the spectral energy distribution. The disks are modelled with the DALI 2D physical-chemical code. Stellar abundances for HD 100546 are derived from archival spectra. Upper limits on HD emission from HD 100546 place an upper limit on the total disk mass of $\\leq0.1\\,M_{\\odot}$. The gas-phase carbon abundance in the atmosphere of this warm Herbig disk is at most moderately depleted compared to the interstellar medium, with [C]/[H]$_{\\rm gas}=(0.1-1.5)\\times 1...

  15. New Parallaxes and a Convergence Analysis for the TW Hya Association

    CERN Document Server

    Donaldson, Jessica K; Gagné, Jonathan; Faherty, Jacqueline K; Boss, Alan P; Keiser, Sandra A

    2016-01-01

    The TW Hya Association (TWA) is a nearby stellar association with an age of $\\sim$ 5-10 Myr. This is an important age for studying the late stages of star and planet formation. We measure the parallaxes of 14 candidate members of TWA. That brings to 38 the total number of individual stars with fully measured kinematics, i.e. proper motion, radial velocity, and parallax, to describe their motions through the Galaxy. We analyze these kinematics to search for convergence to a smaller volume in the past, but we find the association is never much more compact than it is at present. We show that it is difficult to measure traceback ages for associations such as TWA that have expected velocity dispersions of 1-2 km s$^{-1}$ with typical measurement uncertainties. We also use our stellar distances and pre-main-sequence evolutionary tracks to find the average age of the association of 7.9 $\\pm$ 1.0 Myr. Additionally, our parallax measurement of TWA 32 indicates it should be considered a bona fide member of TWA. Two ne...

  16. Numerical simulations of recent proton acceleration experiments with sub-100 TW laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Sinigardi, Stefano, E-mail: sinigardi@bo.infn.it

    2016-09-01

    Recent experiments carried out at the Italian National Research Center, National Optics Institute Department in Pisa, are showing interesting results regarding maximum proton energies achievable with sub-100 TW laser systems. While laser systems are being continuously upgraded in laboratories around the world, at the same time a new trend on stabilizing and making ion acceleration results reproducible is growing in importance. Almost all applications require a beam with fixed performance, so that the energy spectrum and the total charge exhibit moderate shot to shot variations. This result is surely far from being achieved, but many paths are being explored in order to reach it. Some of the reasons for this variability come from fluctuations in laser intensity and focusing, due to optics instability. Other variation sources come from small differences in the target structure. The target structure can vary substantially, when it is impacted by the main pulse, due to the prepulse duration and intensity, the shape of the main pulse and the total energy deposited. In order to qualitatively describe the prepulse effect, we will present a two dimensional parametric scan of its relevant parameters. A single case is also analyzed with a full three dimensional simulation, obtaining reasonable agreement between the numerical and the experimental energy spectrum.

  17. The intimate relation between the low T/W instability and the co-rotation point

    CERN Document Server

    Passamonti, Andrea

    2014-01-01

    We study the low T/W instability associated with the f-mode of differentially rotating stars. Our stellar models are described by a polytropic equation of state and the rotation profile is given by the standard j-constant law. The properties of the relevant oscillation modes, including the instability growth time, are determined from time evolutions of the linearised dynamical equations in Newtonian gravity. In order to analyse the instability we monitor also the canonical energy and angular momentum. Our results demonstrate that the l=m=2 f-mode becomes unstable as soon as a co-rotation point develops inside the star (i.e. whenever there is a point where the mode's pattern speed matches the bulk angular velocity). Considering various degrees of differential rotation, we show that the instability grows faster deep inside the co-rotation region and deduce an empirical relation that correlates the mode frequency and the star's parameters, which captures the main features of the l=m=2 f-mode growth time. This fu...

  18. D-D nuclear fusion processes induced in polyethylene foams by TW Laser-generated plasma

    Science.gov (United States)

    Torrisi, L.; Cutroneo, M.; Cavallaro, S.; Ullschmied, J.

    2015-06-01

    Deuterium-Deuterium fusion processes were generated by focusing the 3 TW PALS Laser on solid deuterated polyethylene targets placed in vacuum. Deuterium ion acceleration of the order of 4 MeV was obtained using laser irradiance Iλ2 ˜ 5 × 1016 W μm2/cm2 on the target. Thin and thick targets, at low and high density, were irradiated and plasma properties were monitored "on line" and "off line". The ion emission from plasma was monitored with Thomson Parabola Spectrometer, track detectors and ion collectors. Fast semiconductor detectors based on SiC and fast plastic scintillators, both employed in time-of-flight configuration, have permitted to detect the characteristic 3.0 MeV protons and 2.45 MeV neutrons emission from the nuclear fusion reactions. From massive absorbent targets we have evaluated the neutron flux by varying from negligible values up to about 5 × 107 neutrons per laser shot in the case of foams targets, indicating a reaction rate of the order of 108 fusion events per laser shot using "advanced targets".

  19. A novel multienzyme complex from a newly isolated facultative anaerobic bacterium, Paenibacillus sp. TW1.

    Science.gov (United States)

    Tachaapaikoon, C; Kyu, K L; Pason, P; Ratanakhanockchai, K

    2012-06-01

    A multienzyme complex from newly isolated Paenibacillus sp. TW1 was purified from pellet-bound enzyme preparations by elution with 0.25% sucrose and 1.0% triethylamine (TEA), ultrafiltration and Sephacryl S-400 gel filtration chromatography. The purified multienzyme complex showed a single protein band on non-denaturing polyacrylamide gel electrophoresis (native-PAGE). The high molecular mass of the purified multienzyme complex was approximately 1,950 kDa. The complex consisted of xylanase and cellulase activities as the major and minor enzyme subunits, respectively. The complex appeared as at least 18 protein bands on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and as 15 xylanases and 6 cellulases on zymograms. The purified multienzyme complex contained xylanase, α-L-arabinofuranosidase, carboxymethyl cellulase (CMCase), avicelase and cellobiohydrolase. The complex could effectively hydrolyze corn hulls, corncobs and sugarcane bagasse. These results indicate that the multienzyme complex that is produced by this bacterium is a large, novel xylanolytic-cellulolytic enzyme complex.

  20. D-D nuclear fusion processes induced in polyethylene foams by TW Laser-generated plasma

    Directory of Open Access Journals (Sweden)

    Torrisi L.

    2015-01-01

    Full Text Available Deuterium-Deuterium fusion processes were generated by focusing the 3 TW PALS Laser on solid deuterated polyethylene targets placed in vacuum. Deuterium ion acceleration of the order of 4 MeV was obtained using laser irradiance Iλ2 ∼ 5 × 1016 W μm2/cm2 on the target. Thin and thick targets, at low and high density, were irradiated and plasma properties were monitored “on line” and “off line”. The ion emission from plasma was monitored with Thomson Parabola Spectrometer, track detectors and ion collectors. Fast semiconductor detectors based on SiC and fast plastic scintillators, both employed in time-of-flight configuration, have permitted to detect the characteristic 3.0 MeV protons and 2.45 MeV neutrons emission from the nuclear fusion reactions. From massive absorbent targets we have evaluated the neutron flux by varying from negligible values up to about 5 × 107 neutrons per laser shot in the case of foams targets, indicating a reaction rate of the order of 108 fusion events per laser shot using “advanced targets”.

  1. Evidence for a Snow Line Beyond the Transitional Radius in the TW Hya Protoplanetary Disk

    CERN Document Server

    Zhang, K; Salyk, C; Blake, G A

    2013-01-01

    We present an observational reconstruction of the radial water vapor content near the surface of the TW Hya transitional protoplanetary disk, and report the first localization of the snow line during this phase of disk evolution. The observations are comprised of Spitzer-IRS, Herschel-PACS, and Herschel-HIFI archival spectra. The abundance structure is retrieved by fitting a two-dimensional disk model to the available star+disk photometry and all observed H2O lines, using a simple step-function parameterization of the water vapor content near the disk surface. We find that water vapor is abundant (~10^{-4} per H2) in a narrow ring, located at the disk transition radius some 4AU from the central star, but drops rapidly by several orders of magnitude beyond 4.2 AU over a scale length of no more than 0.5AU. The inner disk (0.5-4AU) is also dry, with an upper limit on the vertically averaged water abundance of 10^{-6} per H2. The water vapor peak occurs at a radius significantly more distant than that expected fo...

  2. A new grafting technique for tympanoplasty: tympanoplasty with a boomerang-shaped chondroperichondrial graft (TwBSCPG).

    Science.gov (United States)

    Dündar, Rıza; Soy, Fatih Kemal; Kulduk, Erkan; Muluk, Nuray Bayar; Cingi, Cemal

    2014-10-01

    The aim of this study was to introduce a new grafting technique in tympanoplasty that involves use of a boomerang-shaped chondroperichondrial graft (BSCPG). The anatomical and functional results were evaluated. A new tympanoplasty with boomerang-shaped chondroperichondrial graft (TwBSCPG) technique was used in 99 chronic otitis media patients with central or marginal perforation of the tympanic membrane and a normal middle ear mucosa. All 99 patients received chondroperichondrial cartilage grafts with a boomerang-shaped cartilage island left at the anterior and inferior parts. Postoperative follow-ups were conducted at months 1, 6, and 12. Preoperative and postoperative audiological examinations were performed and air-bone gaps were calculated according to the pure-tone averages (PTAs) of the patients. In the preoperative period, most (83.8%) air-bone gaps were ≥ 16 dB; after operating using the TwBSCPG technique, the air-bone gaps decreased to 0-10 dB in most patients (77.8%). In the TwBSCPG patients, the mean preoperative air-bone gap was 22.02 ± 6.74 dB SPL. Postoperatively, the mean postoperative air-bone gap was 8.70 ± 5.74 dB SPL. The TwBSCPG technique therefore decreased the postoperative air-bone gap compared to that preoperatively (p = 0.000, z = -8.645). At the 1-month follow-up, there were six graft perforations and one graft retraction. At the 6-month follow-up, there were nine graft perforations and three graft retractions. At 12 months, there were seven graft perforations and four graft retractions. During the first year after the boomerang tympanoplasty surgery, graft lateralization was not detected in any patient. Retractions were grade 1 according to the Sade classification and were localized to the postero-superior quadrant of the tympanic membrane. The TwBSCPG technique has benefits with respect to postoperative anatomical and audiological results. It prevents perforation of the tympanic membrane at the anterior quadrant and avoids graft

  3. Charon's, Hydra's, and Nix's near IR spectra as seen by New Horizons

    Science.gov (United States)

    Dalle Ore, Cristina M.; Cook, Jason C.; Cruikshank, Dale P.; Protopapa, Silvia; Grundy, William M.; Olkin, Catherine B.; Ennico, Kimberly; Stern, S. Alan; Weaver, Harold A.; Young, Leslie; New Horizons Surface Composition Theme Team

    2016-10-01

    Charon, Pluto's largest satellite, is a predominantly grey-color icy world covered mostly in H2O ice, with spectral evidence for NH3 and/or its hydrates, as previously reported (Cook et al. 2007, ApJ. 663, 1406; Verbiscer et al. 2007, LPSC 38, 2318; Merlin et al. 2010, Icarus, 210, 930; Cook et al. 2014, AAS/DPS Abstracts, 46, #401.04; Holler et al. 2016, submitted, arXiv:1606.05695). In their 2010 work, Merlin et al. reported the presence of ammonia species along with H2O ice both in crystalline and amorphous phase. They introduced a blue component to model the slope present in their near-IR observations, which could not be otherwise reproduced without the adoption of an ad hoc component. The presence of ammonia and H2O in its crystalline form prompted Cook et al. (2007) to suggest cryovolcanism as a favored mechanism of resurfacing although the geological evidence for volcanism reported from New Horizons imaging observations does not appear to be recent (Moore et al. Science, 351, 1284).We analyze one of New Horizons' observations of Charon taken with the LEISA imaging spectrometer from a distance of ~82,000 km at high spatial resolution (4.9 km/pixel). Images from the New Horizons spacecraft reveal a surface with terrains of seemingly different ages and a moderate degree of localized coloration.Hydra was observed by New Horizons at a distance 240,000 and 370,000 hardly resolving its disk. Nix on the other hand was observed from a much more favorable distance of 60,000 and 162,000 km revealing a nearly uniform surface coloration and structure.Although Hydra could hardly be resolved at the flyby distance we have obtained its spectral signature and we compare it with those of Charon and Nix. A feature at ~2.2 µm, corresponding to the NH3 and/or NH3 hydrates, is visible subtly on Charon and clearly on Hydra and Nix hinting at the possibility that NH3 might be less volatile than previously thought and making the need for recent cryovolcanism less crucial

  4. Hydrophysical Evaluation of Wells TW-B, TW-7, UE-6d, U-2gg PSE 3A, U-10L 1, and UE-6e in Yucca Flat

    Energy Technology Data Exchange (ETDEWEB)

    Pohlmann, Karl [Desert Research Inst. (DRI), Las Vegas, NV (United States); Healey, John [Desert Research Inst. (DRI), Las Vegas, NV (United States); Lyles, Bred [Desert Research Inst. (DRI), Reno, NV (United States); Cooper, Clay [Desert Research Inst. (DRI), Reno, NV (United States); Hershey, Ronald L. [Desert Research Inst. (DRI), Reno, NV (United States)

    2017-05-01

    This study evaluated six wells in Yucca Flat in support of the Underground Test Area (UGTA) Activity conducted by the U.S. Department of Energy (DOE) at the Nevada National Security Site (NNSS). Accessibility and groundwater sampling conditions were assessed and if conditions permitted, samples were collected for tritium analysis. Four of the wells, TW-B, UE-6d, UE-6e, and TW-7 were sampled in support of UGTA responses to recommendations made by the Yucca Flat/Climax Mine External Peer Review Committee (Navarro, 2016). In addition to its role in support of these responses, TW-7 was included because it is listed in the NNSS Integrated Groundwater Sampling Plan (DOE, 2014) as a required sampling location, although it had not been sampled since 1994. U-2gg PSE 3A and U-10L 1 were evaluated to determine whether deteriorating well conditions can be addressed so that these wells can be used as additional sampling points in Yucca Flat.

  5. Early onset and severe clinical course associated with the m.5540G>A mutation in MT-TW

    Directory of Open Access Journals (Sweden)

    Jorge L. Granadillo

    2014-01-01

    Full Text Available We report a patient harboring a de novo m.5540G>A mutation affecting the MT-TW gene coding for the mitochondrial tryptophan-transfer RNA. This patient presented with atonic–myoclonic epilepsy, bilateral sensorineural hearing loss, ataxia, motor regression, ptosis, and pigmentary retinopathy. Our proband had an earlier onset and more severe phenotype than the first reported patient harboring the same mutation. We discuss her clinical presentation and compare it with the only previously published case.

  6. Poverty, violence, and family disorganization: Three "Hydras" and their role in children's street movement in Bangladesh.

    Science.gov (United States)

    Reza, Md Hasan

    2016-05-01

    The increasing number of children running away from home in Bangladesh is a major concern, and in need of critical attention. This yearlong study explores why children leave home with a sample of street children in Dhaka, Bangladesh. Purposive sampling from three locations in Dhaka yielded a sample of 75 homeless children aged 10-17. For each participant, a 60-90min in-depth qualitative interview was conducted multiple times. While the dominant explanations rely on poverty or abuse, the findings of this study reveal that the cause is actually three heads of a Hydra monster: poverty, abuse, and family disorganization and their interactions. It shows that the primary reasons for children breaking from their family are all interrelated. The findings from this study are likely to add knowledge regarding the issues and may lead to preventative interventions for street children and their families.

  7. GTRF Calculations Using Hydra-TH (THM.CFD.P5.05)

    Energy Technology Data Exchange (ETDEWEB)

    Bakosi, Jozsef [Los Alamos National Laboratory; Christon, Mark A. [Los Alamos National Laboratory; Francois, Marianne M. [Los Alamos National Laboratory; Lowrie, Robert B. [Los Alamos National Laboratory; Nourgaliev, Robert [Los Alamos National Laboratory

    2012-09-05

    This report describes the work carried out for completion of the Thermal Hydraulics Methods (THM) Level 3 Milestone THM.CFD.P5.05 for the Consortium for Advanced Simulation of Light Water Reactors (CASL). A series body-fitted computational meshes have been generated by Numeca's Hexpress/Hybrid, a.k.a. 'Spider', meshing technology for the V5H 3x3 and 5x5 rod bundle geometry used to compute the fluid dynamics of grid-to-rod fretting (GTRF). Spider is easy to use, fast, and automatically generates high-quality meshes for extremely complex geometries, required for the GTRF problem. Hydra-TH has been used to carry out large-eddy simulations on both 3x3 and 5x5 geometries, using different mesh resolutions. The results analyzed show good agreement with Star-CCM+ simulations and experimental data.

  8. VizieR Online Data Catalog: Hydra I Cluster Catalogue (HCC) (Misgeld+, 2008)

    Science.gov (United States)

    Misgeld, I.; Mieske, S.; Hilker, M.

    2008-07-01

    The obtained photometric parameters along with the available radial velocities for all early-type galaxies in our sample (111 objects) are presented in the Hydra I Cluster Catalogue (HCC). For each galaxy right ascension, declination, extinction corrected magnitude V and colour V-I, central surface brightness and scale length of an exponential fit to the surface brightness profile, effective surface brightness, effective radius and profile shape index n, as obtained from a Sersic fit, are given. The physical scale is 0.2kpc/arcsec at the assumed distance modulus of (m-M)=33.07mag. The radial velocities are taken from our study and from Christlein & Zabludoff (2003ApJ...591..764C). (1 data file).

  9. Toxicity of water and sediment from stormwater retarding basins to Hydra hexactinella

    DEFF Research Database (Denmark)

    Rosenkrantz, Rikke Tjørnhøj; Pollino, Carmel A.; Nugegoda, Dayanthi;

    2008-01-01

    of 50 ml/L and 100 ml/L, while the 7 h pulse exposure caused a significant increase in the mean population growth rate compared to the control. Water samples from the two other retarding basins were found non-toxic to H. hexactinella. This is the first study to employ sediment tests with Hydra spp....... on stormwater sediments and a lower population growth rate was observed for organisms exposed to sediment from the Avoca St retarding basins. The behavioral study showed that H. hexactinella tended to avoid the sediment-water interface when exposed to sediment from all retarding basins, compared...... to the reference sediment. Further work is needed to determine the long-term effects of stormwater polluted sediments and acute effects due to organism exposure to short-term high concentrations during rain events. (C) 2008 Elsevier Ltd. All rights reserved....

  10. GTRF Calculations Using Hydra-TH (L3 Milestone THM.CFD.P5.05)

    Energy Technology Data Exchange (ETDEWEB)

    Bakosi, Jozsef [Los Alamos National Laboratory; Christon, Mark A. [Los Alamos National Laboratory; Francois, Marianne M. [Los Alamos National Laboratory; Lowrie, Robert B. [Los Alamos National Laboratory; Nourgaliev, Robert [Los Alamos National Laboratory

    2012-09-05

    This report describes the work carried out for completion of the Thermal Hydraulics Methods (THM) Level 3 Milestone THM.CFD.P5.05 for the Consortium for Advanced Simulation of Light Water Reactors (CASL). A series of body-fitted computational meshes have been generated by Numeca's Hexpress/Hybrid, a.k.a. 'Spider', meshing technology for the V5H 3 x 3 and 5 x 5 rod bundle geometries and subsequently used to compute the fluid dynamics of grid-to-rod fretting (GTRF). Spider is easy to use, fast, and automatically generates high-quality meshes for extremely complex geometries, required for the GTRF problem. Hydra-TH has been used to carry out large-eddy simulations on both 3 x 3 and 5 x 5 geometries, using different mesh resolutions. The results analyzed show good agreement with Star-CCM+ simulations and experimental data.

  11. 2D HYDRA Calculations of Magneto-Rayleigh-Taylor Growth and Feedthrough in Cylindrical Liners

    Science.gov (United States)

    Weis, Matthew; Zhang, Peng; Lau, Y. Y.; Gilgenbach, Ronald; Peterson, Kyle; Hess, Mark

    2014-10-01

    Cylindrical liner implosions are susceptible to the magneto-Rayleigh-Taylor instability (MRT), along with the azimuthal current-carrying modes (sausage, kink, etc). ``Feedthrough'' of these instabilities has a strong influence on the integrity of the liner/fuel interface in the magnetized liner inertial fusion concept (MagLIF). The linearized ideal MHD equations can be solved to quantify these effects, including the presence of an effective gravity and an axial magnetic field. We investigate the potential of this field to mitigate feedthrough, due to MRT growth from various initial surface finishes (seeded, rough), throughout the implosion using our analytic results and the LLNL code, HYDRA. We will present both low and high convergence cases. Lastly, we illustrate the effect shock compression can have on feedthrough in seeded liners for various fill gases (cold and pre-heated) and magnetic field configurations. M. R. Weis was supported by the Sandia National Laboratories.

  12. Development of the two-part pattern during regeneration of the head in hydra

    DEFF Research Database (Denmark)

    Bode, Matthias; Awad, T A; Koizumi, O;

    1988-01-01

    The head of a hydra is composed of two parts, a domed hypostome with a mouth at the top and a ring of tentacles below. When animals are decapitated a new head regenerates. During the process of regeneration the apical tip passes through a transient stage in which it exhibits tentacle...... began evaginating in a ring, both the TS-19 antigen and RLI+ ganglion cells gradually disappeared from the presumptive hypostome area and RLI+ sensory cells appeared at the apex. By tracking tissue movements during morphogenesis it became clear that the apical cap, in which these changes took place, did...... not undergo tissue turnover. The implications of this tentacle-like stage for patterning the two-part head are discussed....

  13. Jet-Intracluster Medium interaction in Hydra A. II The Effect of Jet Precession

    CERN Document Server

    Nawaz, M A; Wagner, A Y; Sutherland, R S; McNamara, B R

    2016-01-01

    We present three dimensional relativistic hydrodynamical simulations of a precessing jet interacting with the intracluster medium and compare the simulated jet structure with the observed structure of the Hydra A northern jet. For the simulations, we use jet parameters obtained in the parameter space study of the first paper in this series and probe different values for the precession period and precession angle. We find that for a precession period P = 1 Myr and a precession angle = 20 degree the model reproduces i) the curvature of the jet, ii) the correct number of bright knots within 20 kpc at approximately correct locations, and iii) the turbulent transition of the jet to a plume. The Mach number of the advancing bow shock = 1.85 is indicative of gentle cluster atmosphere heating during the early stages of the AGN's activity.

  14. CIRCUMBINARY CHAOS: USING PLUTO'S NEWEST MOON TO CONSTRAIN THE MASSES OF NIX AND HYDRA

    Energy Technology Data Exchange (ETDEWEB)

    Youdin, Andrew N.; Kratter, Kaitlin M.; Kenyon, Scott J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2012-08-10

    The Pluto system provides a unique local laboratory for the study of binaries with multiple low-mass companions. In this paper, we study the orbital stability of P4, the most recently discovered moon in the Pluto system. This newfound companion orbits near the plane of the Pluto-Charon (PC) binary, roughly halfway between the two minor moons Nix and Hydra. We use a suite of few body integrations to constrain the masses of Nix and Hydra, and the orbital parameters of P4. For the system to remain stable over the age of the solar system, the masses of Nix and Hydra likely do not exceed 5 Multiplication-Sign 10{sup 16} kg and 9 Multiplication-Sign 10{sup 16} kg, respectively. These upper limits assume a fixed mass ratio between Nix and Hydra at the value implied by their median optical brightness. Our study finds that stability is more sensitive to their total mass and that a downward revision of Charon's eccentricity (from our adopted value of 0.0035) is unlikely to significantly affect our conclusions. Our upper limits are an order of magnitude below existing astrometric limits on the masses of Nix and Hydra. For a density at least that of ice, the albedos of Nix and Hydra would exceed 0.3. This constraint implies they are icy, as predicted by giant impact models. Even with these low masses, P4 only remains stable if its eccentricity e {approx}< 0.02. The 5:1 commensurability with Charon is particularly unstable, combining stability constraints with the observed mean motion places the preferred orbit for P4 just exterior to the 5:1 resonance. These predictions will be tested when the New Horizons satellite visits Pluto. Based on the results for the PC system, we expect that circumbinary, multi-planet systems will be more widely spaced than their singleton counterparts. Further, circumbinary exoplanets close to the three-body stability boundary, such as those found by Kepler, are less likely to have other companions nearby.

  15. Cell type complexity in the basal metazoan Hydra is maintained by both stem cell based mechanisms and transdifferentiation.

    Science.gov (United States)

    Siebert, Stefan; Anton-Erxleben, Friederike; Bosch, Thomas C G

    2008-01-01

    Understanding the mechanisms controlling the stability of the differentiated cell state is a fundamental problem in biology. To characterize the critical regulatory events that control stem cell behavior and cell plasticity in vivo in an organism at the base of animal evolution, we have generated transgenic Hydra lines [Wittlieb, J., Khalturin, K., Lohmann, J., Anton-Erxleben, F., Bosch, T.C.G., 2006. Transgenic Hydra allow in vivo tracking of individual stem cells during morphogenesis. Proc. Natl. Acad. Sci. U. S. A. 103, 6208-6211] which express eGFP in one of the differentiated cell types. Here we present a novel line which expresses eGFP specifically in zymogen gland cells. These cells are derivatives of the interstitial stem cell lineage and have previously been found to express two Dickkopf related genes [Augustin, R., Franke, A., Khalturin, K., Kiko, R., Siebert, S. Hemmrich, G., Bosch, T.C.G., 2006. Dickkopf related genes are components of the positional value gradient in Hydra. Dev. Biol. 296 (1), 62-70]. In the present study we have generated transgenic Hydra in which eGFP expression is under control of the promoter of one of them, HyDkk1/2/4 C. Transgenic Hydra recapitulate faithfully the previously described graded activation of HyDkk1/2/4 C expression along the body column, indicating that the promoter contains all elements essential for spatial and temporal control mechanisms. By in vivo monitoring of eGFP+ gland cells, we provide direct evidence for continuous transdifferentiation of zymogen cells into granular mucous cells in the head region. We also show that in this tissue a subpopulation of mucous gland cells directly derives from interstitial stem cells. These findings indicate that both stem cell-based mechanisms and transdifferentiation are involved in normal development and maintenance of cell type complexity in Hydra. The results demonstrate a remarkable plasticity in the differentiation capacity of cells in an organism which diverged before

  16. Suzaku Observations of the Hydra A Cluster out to the Virial Radius

    Science.gov (United States)

    Sato, Takuya; Sasaki, Toru; Matsushita, Kyoko; Sakuma, Eri; Sato, Kosuke; Fujita, Yutaka; Okabe, Nobuhiro; Fukazawa, Yasushi; Ichikawa, Kazuya; Kawaharada, Madoka; Nakazawa, Kazuhiro; Ohashi, Takaya; Ota, Naomi; Takizawa, Motokazu; Tamura, Takayuki

    2012-10-01

    We report on Suzaku observations of the northern half of the Hydra A cluster out to ˜ 1.4 Mpc, reaching the virial radius. There are the first Suzaku observations of a medium-size (kT ˜ 3 keV) cluster out to the virial radius. Two observations were conducted, north-west and north-east offsets, which continue in a filament direction and a void direction of the large-scale structure of the Universe, respectively. The X-ray emission and distribution of galaxies elongate in the filament direction. The temperature profiles in the two directions are mostly consistent with each other within the error bars, and drop to 1.5 keV at 1.5 r500 . As observed by Suzaku in hot clusters, the entropy profile becomes flatter beyond r500 , in disagreement with the r1.1 relationship, which is expected from accretion shock heating models. When scaled with the average intracluster medium (ICM) temperature, the entropy profiles of clusters observed with Suzaku are universal, and do not depend on the system mass. The hydrostatic mass values in the void and filament directions are in good agreement, and the Navarro, Frenk, and White universal mass profile represents the hydrostatic mass distribution up to ˜ 2r500 . Beyond r500 , the ratio of the gas mass to the hydrostatic mass exceeds the result of the Wilkinson microwave anisotropy probe, and at r100 , these ratios in the filament and void directions reach 0.4 and 0.3, respectively. We discuss possible deviations from the hydrostatic equilibrium at cluster outskirts. We derived radial profiles of the gas-mass-to-light ratio and the iron-mass-to-light ratio out to the virial radius. Within r500 , the iron-mass-to-light ratio of the Hydra A cluster was compared with those in other clusters observed with Suzaku.

  17. Toxaphene affects the levels of mRNA transcripts that encode antioxidant enzymes in Hydra.

    Science.gov (United States)

    Woo, Seonock; Lee, Aekyung; Won, Hyokyoung; Ryu, Jae-Chun; Yum, Seungshic

    2012-06-01

    We evaluated toxaphene-induced acute toxicity in Hydra magnipapillata. The median lethal concentrations of the animals (LC(50)) were determined to be 34.5 mg/L, 25.0 mg/L and 12.0 mg/L after exposure to toxaphene for 24 h, 48 h and 72 h, respectively. Morphological responses of hydra polyps to a range of toxaphene concentrations suggested that toxaphene negatively affects the nervous system of H. magnipapillata. We used real-time quantitative PCR of RNA extracted from polyps exposed to two concentrations of toxaphene (0.3 mg/L and 3 mg/L) for 24 h to evaluate the differential regulation of levels of transcripts that encode six antioxidant enzymes (CAT, G6PD, GPx, GR, GST and SOD), two proteins involved in detoxification and molecular stress responses (CYP1A and UB), and two proteins involved in neurotransmission and nerve cell differentiation (AChE and Hym-355). Of the genes involved in antioxidant responses, the most striking changes were observed for transcripts that encode GPx, G6PD, SOD, CAT and GST, with no evident change in levels of transcripts encoding GR. Levels of UB and CYP1A transcripts increased in a dose-dependent manner following exposure to toxaphene. Given that toxaphene-induced neurotoxicity was not reflected in the level of AChE transcripts and only slight accumulation of Hym-355 transcript was observed only at the higher of the two doses of toxaphene tested, there remains a need to identify transcriptional biomarkers for toxaphene-mediated neurotoxicity in H. magnipapillata. Transcripts that respond to toxaphene exposure could be valuable biomarkers for stress levels in H. magnipapillata and may be useful for monitoring the pollution of aquatic environments.

  18. Discovery of very high velocity outflow in V Hydra - Wind from an accretion disk in a binary?

    Science.gov (United States)

    Sahai, R.; Wannier, P. G.

    1988-01-01

    High-resolution observations of lines from the CO v = 1-0 vibration-rotation band at 4.6 microns, taken with the FTS/KPNO 4-m telescope, are reported for the carbon-rich red giant V Hydra, which is surrounded by an extended expanding molecular envelope resulting from extensive mass loss. The spectrum shows, in addition to the expected absorption at the outflow velocity of the envelope, absorption extending up to 120 km/s bluewards of the stellar velocity. A comparison of the spectrum observed at two epochs shows that the high-velocity absorption features change with time. It is suggested that the observed high-velocity features in V Hydra arise in a high-velocity polar outflow from an accretion disk in a binary system, as proposed in the mass-loss model for bipolar envelopes by Morris (1988).

  19. Karyotyping and single-gene detection using fluorescence in situ hybridization on chromosomes of Hydra magnipapillata (Cnidaria: Hydrozoa

    Directory of Open Access Journals (Sweden)

    B Anokhin

    2010-12-01

    Full Text Available The fresh water polyp Hydra L., 1758 (Cnidaria, Hydrozoa plays a key role as a model organism in modern evolutionary and developmental biology. A complete genome sequence has been published recently for Hydra magnipapillata Ito, 1947 and molecular data are rapidly accumulating in the literature, but little information is available on its chromosomes. In this study, an efficient fluorescence in situ hybridization (FISH method is described for H. magnipapillata which not only allows identification of the chromosomes but also visualization of the location of individual genetic loci. Together with cDNA and genomic sequencing this may provide the foundation for increasingly precise genetic and physical mapping in this basal metazoan model organism.

  20. GLOMOMIDIELLA N. GEN. (FORAMINIFERA, MILIOLATA, NEODISCIDAE: A NEW GENUS FROM THE LATE GUADALUPIAN-LOPINGIAN OF HYDRA ISLAND (GREECE

    Directory of Open Access Journals (Sweden)

    DANIEL VACHARD

    2008-11-01

    Full Text Available A new genus of Foraminifera (Miliolata, Cornuspiroidea, Neodiscidae is erected from the late Guadalupian (Capitanian = Midian to Lopingian sedimentary succession of the island of Hydra (Greece. It represents an important phylogenetic form, probably at the origin of several genera (or subfamilies of the authors that became relatively widespread during the Lopingian (Late Permian. Glomomidiella n. gen. is characterized by an entirely glomospiral coiling and rudimentary pseudoseptation. 

  1. TW-37, a Small-Molecule Inhibitor of Bcl-2, Inhibits Cell Growth and Induces Apoptosis in Pancreatic Cancer: Involvement of Notch-1 Signaling Pathway

    OpenAIRE

    2009-01-01

    Overexpression of Bcl-2 family proteins has been found in a variety of aggressive human carcinomas, including pancreatic cancer, suggesting that specific agents targeting Bcl-2 family proteins would be valuable for pancreatic cancer therapy. We have previously reported that TW-37, a small-molecule inhibitor of Bcl-2 family proteins, inhibited cell growth and induced apoptosis in pancreatic cancer. However, the precise role and the molecular mechanism of action of TW-37 have not been fully elu...

  2. Hydra II: a faint and compact Milky Way dwarf galaxy found in the Survey of the Magellanic Stellar History

    CERN Document Server

    Martin, Nicolas F; Besla, Gurtina; Olsen, Knut; Walker, Alistair R; Vivas, A Katherina; Gruendl, Robert A; Muñoz, Ricardo R; Blum, Robert D; Saha, Abhijit; Conn, Blair C; Bell, Eric F; Chu, You-Hua; Cioni, Maria-Rosa L; de Boer, Thomas J L; Gallart, Carme; Jin, Shoko; Kunder, Andrea; Majewski, Steven R; Martinez-Delgado, David; Monachesi, Antonela; Monelli, Matteo; Monteagudo, Lara; Noël, Noelia E D; Olszewski, Edward W; Stringfellow, Guy S; van der Marel, Roeland P; Zaritsky, Denis

    2015-01-01

    We present the discovery of a new dwarf galaxy, Hydra II, found serendipitously within the data from the ongoing Survey of the MAgellanic Stellar History (SMASH) conducted with the Dark Energy Camera on the Blanco 4m Telescope. The new satellite is compact (r_h = 68 +/- 11 pc) and faint (M_V = -4.8 +/- 0.3), but well within the realm of dwarf galaxies. The stellar distribution of HydraII in the color-magnitude diagram is well-described by a metal-poor ([Fe/H] = -2.2) and old (13 Gyr) isochrone and shows a distinct blue horizontal branch, some possible red clump stars, and faint stars that are suggestive of blue stragglers. At a heliocentric distance of 134 +/- 10 kpc, Hydra II is located in a region of the Galactic halo that models have suggested may host material from the leading arm of the Magellanic Stream. A comparison with N-body simulations hints that the new dwarf galaxy could be or could have been a satellite of the Magellanic Clouds.

  3. Hydratools manual version 1.0, documentation for a MATLAB®-based post-processing package for the Sontek Hydra

    Science.gov (United States)

    Martini, Marinna; Sherwood, Chris; Horwitz, Rachel; Ramsey, Andree; Lightsom, Fran; Lacy, Jessie; Xu, Jingping

    2006-01-01

    The Sediment Transport Instrumentation Group (STG) at the U.S. Geological Survey (USGS) Woods Hole Science Center has a long-standing comitment to providing scientists with high quality oceanographic data. To meet this commitment, STG personnel are vigilant in checking data as well as hardware for signs of instrument malfunction. STG data sets are accompanied by processing histories to detail data processing procedures that may have modified the natural data signal while removing noise from the data. The history also allows the data to be reprocessed in the ligth of new insight into instrument function and moored conditions. This toolbox was compiled to meet these data quality commitments for data generated by Sontek Hydra systems using both ADV and PCADP probes. In the mid 1900's, the USGS Coastal and Marine Program began frequent deployments of Sontek Hydra systems in support of projects in estuaries, coastal, and continental shelf regions nationwide. Hydra data sets are large and complex in structure, and existing processing and editing tools consisted of fragments of MATLAB code written by USGS scientists to satisfy personal research needs. This code did not meet STG quality control criteria. This toolbox permits engineers and scientists to monitor data quality by: 1.\tprocessing data with interactive critical review;

  4. Bringing ATLAS production to HPC resources - A use case with the Hydra supercomputer of the Max Planck Society

    Science.gov (United States)

    Kennedy, J. A.; Kluth, S.; Mazzaferro, L.; Walker, Rodney

    2015-12-01

    The possible usage of HPC resources by ATLAS is now becoming viable due to the changing nature of these systems and it is also very attractive due to the need for increasing amounts of simulated data. In recent years the architecture of HPC systems has evolved, moving away from specialized monolithic systems, to a more generic linux type platform. This change means that the deployment of non HPC specific codes has become much easier. The timing of this evolution perfectly suits the needs of ATLAS and opens a new window of opportunity. The ATLAS experiment at CERN will begin a period of high luminosity data taking in 2015. This high luminosity phase will be accompanied by a need for increasing amounts of simulated data which is expected to exceed the capabilities of the current Grid infrastructure. ATLAS aims to address this need by opportunistically accessing resources such as cloud and HPC systems. This paper presents the results of a pilot project undertaken by ATLAS and the MPP/RZG to provide access to the HYDRA supercomputer facility. Hydra is the supercomputer of the Max Planck Society, it is a linux based supercomputer with over 80000 cores and 4000 physical nodes located at the RZG near Munich. This paper describes the work undertaken to integrate Hydra into the ATLAS production system by using the Nordugrid ARC-CE and other standard Grid components. The customization of these components and the strategies for HPC usage are discussed as well as possibilities for future directions.

  5. Hydra as a model organism to decipher the toxic effects of copper oxide nanorod: Eco-toxicogenomics approach

    Science.gov (United States)

    Murugadas, Anbazhagan; Zeeshan, Mohammed; Thamaraiselvi, Kaliannan; Ghaskadbi, Surendra; Akbarsha, Mohammad Abdulkader

    2016-07-01

    Nanotechnology has emerged as a powerful field of applied research. However, the potential toxicity of nano-materials is a cause of concern. A thorough toxicological investigation is required before a nanomaterial is evaluated for application of any kind. In this context, there is concerted effort to find appropriate test systems to assess the toxicity of nanomaterials. Toxicity of a nanomaterial greatly depends on its physicochemical properties and the biological system with which it interacts. The present research was carried out with a view to generate data on eco-toxicological impacts of copper oxide nanorod (CuO NR) in Hydra magnipapillata 105 at organismal, cellular and molecular levels. Exposure of hydra to CuO NR resulted in severe morphological alterations in a concentration- as well as duration-dependent manner. Impairment of feeding, population growth, and regeneration was also observed. In vivo and in vitro analyses revealed induction of oxidative stress, genotoxicity, and molecular machinery of apoptotic cell death, accompanied by disruption of cell cycle progression. Taken together, CuO nanorod is potentially toxic to the biological systems. Also, hydra offers potential to be used as a convenient model organism for aquatic ecotoxicological risk assessment of nanomaterials.

  6. Hydra as a model organism to decipher the toxic effects of copper oxide nanorod: Eco-toxicogenomics approach

    Science.gov (United States)

    Murugadas, Anbazhagan; Zeeshan, Mohammed; Thamaraiselvi, Kaliannan; Ghaskadbi, Surendra; Akbarsha, Mohammad Abdulkader

    2016-01-01

    Nanotechnology has emerged as a powerful field of applied research. However, the potential toxicity of nano-materials is a cause of concern. A thorough toxicological investigation is required before a nanomaterial is evaluated for application of any kind. In this context, there is concerted effort to find appropriate test systems to assess the toxicity of nanomaterials. Toxicity of a nanomaterial greatly depends on its physicochemical properties and the biological system with which it interacts. The present research was carried out with a view to generate data on eco-toxicological impacts of copper oxide nanorod (CuO NR) in Hydra magnipapillata 105 at organismal, cellular and molecular levels. Exposure of hydra to CuO NR resulted in severe morphological alterations in a concentration- as well as duration-dependent manner. Impairment of feeding, population growth, and regeneration was also observed. In vivo and in vitro analyses revealed induction of oxidative stress, genotoxicity, and molecular machinery of apoptotic cell death, accompanied by disruption of cell cycle progression. Taken together, CuO nanorod is potentially toxic to the biological systems. Also, hydra offers potential to be used as a convenient model organism for aquatic ecotoxicological risk assessment of nanomaterials. PMID:27417574

  7. Determination of Mercury in Ayurvedic Dietary Supplements That Are Not Rasa Shastra Using the Hydra-C Direct Mercury Analyzer

    Directory of Open Access Journals (Sweden)

    Amir A. Abdalla

    2013-01-01

    Full Text Available Mercury has been determined in Ayurvedic dietary supplements (Trifala, Trifala Guggulu, Turmeric, Mahasudarshan, Yograj, Shatawari, Hingwastika, Shatavari, and Shilajit by inductively coupled plasma-mass spectrometry (ICP-MS and direct mercury analysis using the Hydra-C direct mercury analyzer (Teledyne Leeman Labs Hudson, NH, USA. Similar results were obtained from the two methods, but the direct mercury analysis method was much faster and safer and required no microwave digestion (unlike ICP-MS. Levels of mercury ranged from 0.002 to 56 μg/g in samples of dietary supplements. Standard reference materials Ephedra 3240 and tomato leaves that were from the National Institute of Standard and Technology (NIST and dogfish liver (DOLT3 that was from the Canadian Research Council were analyzed using Hydra-C method. Average mercury recoveries were 102% (RSD% 0.0018, 100% (RSD% 0.0009, and 101% (RSD% 0.0729, respectively. Hydra-C method Limit Of Quantitation was 0.5 ng.

  8. [Cultivation of a novel cellulase/xylanase producer, Trichoderma longibrachiatum mutant TW 1-59-27: production of the enzyme preparation and the study of its properties].

    Science.gov (United States)

    Bekkarevicha, A O; Nemashkalov, V A; Koshelev, A V; Goryazchev, D A; Bubnova, T V; Matys, V Yu; Osipov, D O; Kondrat'eva, E G; Okunev, O N; Sinitsyn, A P

    2015-01-01

    As a result of gamma-mutagenesis of Trichoderma longibrachiatum TW1 and the subsequent selection of improved producers, a novel mutant strain, TW1-59-27, capable of efficiently secreting cellulase and xylanase was obtained. In a fed-batch cultivation, the new TW1-59-27 mutant was significantly more active compared with the original TW1 strain. For instance, the activities of cellulase (towards carboxymethylcellulose) and xylanase in the culture broth (CB) increased by 1.8 and two times, respectively, and the protein content increased by 1.47 times. The activity of these enzymes in the dry enzyme preparation derived from the CB of the TW1-59-27 mutant was 1.3-1.8 times higher than that in the preparation derived from the original TW1 strain. It was established that the cellulase from the enzyme preparation of the mutant strain demonstrated the maximum activity at 55-65 degrees C; it occurred in xylanase at 60 degrees C. The pH optima of these enzymes were pH 4.5-5.0 and pH 5.0-6.0, respectively. It was shown that the content of endoglucanases in the enzyme preparation increased from 7% to 13.5%; the effect is largely driven by the secretion of endoglucanase-1. An enzyme preparation with increased endoglucanase-1 content is promising for use as a feed additive in agriculture.

  9. HyDRA: gene prioritization via hybrid distance-score rank aggregation.

    Science.gov (United States)

    Kim, Minji; Farnoud, Farzad; Milenkovic, Olgica

    2015-04-01

    Gene prioritization refers to a family of computational techniques for inferring disease genes through a set of training genes and carefully chosen similarity criteria. Test genes are scored based on their average similarity to the training set, and the rankings of genes under various similarity criteria are aggregated via statistical methods. The contributions of our work are threefold: (i) first, based on the realization that there is no unique way to define an optimal aggregate for rankings, we investigate the predictive quality of a number of new aggregation methods and known fusion techniques from machine learning and social choice theory. Within this context, we quantify the influence of the number of training genes and similarity criteria on the diagnostic quality of the aggregate and perform in-depth cross-validation studies; (ii) second, we propose a new approach to genomic data aggregation, termed HyDRA (Hybrid Distance-score Rank Aggregation), which combines the advantages of score-based and combinatorial aggregation techniques. We also propose incorporating a new top-versus-bottom (TvB) weighting feature into the hybrid schemes. The TvB feature ensures that aggregates are more reliable at the top of the list, rather than at the bottom, since only top candidates are tested experimentally; (iii) third, we propose an iterative procedure for gene discovery that operates via successful augmentation of the set of training genes by genes discovered in previous rounds, checked for consistency. Fundamental results from social choice theory, political and computer sciences, and statistics have shown that there exists no consistent, fair and unique way to aggregate rankings. Instead, one has to decide on an aggregation approach using predefined set of desirable properties for the aggregate. The aggregation methods fall into two categories, score- and distance-based approaches, each of which has its own drawbacks and advantages. This work is motivated by the

  10. Hydra: software for tailored processing of H/D exchange data from MS or tandem MS analyses

    Directory of Open Access Journals (Sweden)

    Bennett Melissa

    2009-05-01

    Full Text Available Abstract Background Hydrogen/deuterium exchange mass spectrometry (H/DX-MS experiments implemented to characterize protein interaction and protein folding generate large quantities of data. Organizing, processing and visualizing data requires an automated solution, particularly when accommodating new tandem mass spectrometry modes for H/DX measurement. We sought to develop software that offers flexibility in defining workflows so as to support exploratory treatments of H/DX-MS data, with a particular focus on the analysis of very large protein systems and the mining of tandem mass spectrometry data. Results We present a software package ("Hydra" that supports both traditional and exploratory treatments of H/DX-MS data. Hydra's software architecture tolerates flexible data analysis procedures by allowing the addition of new algorithms without significant change to the underlying code base. Convenient user interfaces ease the organization of raw data files and input of peptide data. After executing a user-defined workflow, extracted deuterium incorporation values can be visualized in tabular and graphical formats. Hydra also automates the extraction and visualization of deuterium distribution values. Manual validation and assessment of results is aided by an interface that aligns extracted ion chromatograms and mass spectra, while providing a means of rapidly reprocessing the data following manual adjustment. A unique feature of Hydra is the automated processing of tandem mass spectrometry data, demonstrated on a large test data set in which 40,000 deuterium incorporation values were extracted from replicate analysis of approximately 1000 fragment ions in one hour using a typical PC. Conclusion The customizable workflows and user-friendly interfaces of Hydra removes a significant bottleneck in processing and visualizing H/DX-MS data and helps the researcher spend more time executing new experiments and interpreting results. This increased

  11. Scaling laws for energetic ions from the commissioning of the new Los Alamos National Laboratory 200 TW Trident laser.

    Science.gov (United States)

    Flippo, K A; Workman, J; Gautier, D C; Letzring, S; Johnson, R P; Shimada, T

    2008-10-01

    The recent Los Alamos National Laboratory Trident laser enhanced from 30 to 200 TW in power allows more than 100 J to be delivered on target in 500 fs with a spot size smaller than 12 microm at full width at half maximum. 15 microm flat-foil targets have been observed to produce proton beams in excess of 50 MeV at an intensity of only approximately 4x10(19) W/cm(2) with efficiencies approaching 5%. The Trident laser beam characteristics are presented along with the data compared to published scaling laws for proton acceleration.

  12. Understanding Engagement in HIV Risk and Prevention Research Among Black Young Men Who Have Sex with Men and Transgender Women in the District of Columbia

    Science.gov (United States)

    Houston, Ebony; Peterson, James; Kuo, Irene; Magnus, Manya

    2016-01-01

    Abstract Purpose: To develop optimal methods to study sexual health among black young men who have sex with men and transgender women (BYMSM/TW). Methods: We conducted a mixed-methods prospective study to identify recruitment and retention strategies for BYMSM/TW (age 16–21) in Washington D.C., and describe HIV risk behaviors and context. Results: Incentivized peer referral was highly productive, and 60% of BYMSM/TW were retained for 3 months. Participants reported high levels of sexual risk, homophobia, racism, and maternal support. Conclusion: BYMSM/TW studies should utilize a combination of peer-based, in-person, and technology-based recruiting strategies. Additional research is needed to leverage mobile technology and social media to enhance retention. PMID:26651365

  13. Structure and Dynamics of the Accretion Process and Wind in TW Hya

    Science.gov (United States)

    Dupree, A. K.; Brickhouse, N. S.; Cranmer, S. R.; Berlind, P.; Strader, Jay; Smith, Graeme H.

    2014-07-01

    Time-domain spectroscopy of the classical accreting T Tauri star, TW Hya, covering a decade and spanning the far UV to the near-infrared spectral regions can identify the radiation sources, the atmospheric structure produced by accretion, and properties of the stellar wind. On timescales from days to years, substantial changes occur in emission line profiles and line strengths. Our extensive time-domain spectroscopy suggests that the broad near-IR, optical, and far-uv emission lines, centered on the star, originate in a turbulent post-shock region and can undergo scattering by the overlying stellar wind as well as some absorption from infalling material. Stable absorption features appear in Hα, apparently caused by an accreting column silhouetted in the stellar wind. Inflow of material onto the star is revealed by the near-IR He I 10830 Å line, and its free-fall velocity correlates inversely with the strength of the post-shock emission, consistent with a dipole accretion model. However, the predictions of hydrogen line profiles based on accretion stream models are not well-matched by these observations. Evidence of an accelerating warm to hot stellar wind is shown by the near-IR He I line, and emission profiles of C II, C III, C IV, N V, and O VI. The outflow of material changes substantially in both speed and opacity in the yearly sampling of the near-IR He I line over a decade. Terminal outflow velocities that range from 200 km s-1 to almost 400 km s-1 in He I appear to be directly related to the amount of post-shock emission, giving evidence for an accretion-driven stellar wind. Calculations of the emission from realistic post-shock regions are needed. 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

  14. Proteomic screen in the simple metazoan Hydra identifies 14-3-3 binding proteins implicated in cellular metabolism, cytoskeletal organisation and Ca2+ signalling

    Directory of Open Access Journals (Sweden)

    Imhof Axel

    2007-07-01

    Full Text Available Abstract Background 14-3-3 proteins have been implicated in many signalling mechanisms due to their interaction with Ser/Thr phosphorylated target proteins. They are evolutionarily well conserved in eukaryotic organisms from single celled protozoans and unicellular algae to plants and humans. A diverse array of target proteins has been found in higher plants and in human cell lines including proteins involved in cellular metabolism, apoptosis, cytoskeletal organisation, secretion and Ca2+ signalling. Results We found that the simple metazoan Hydra has four 14-3-3 isoforms. In order to investigate whether the diversity of 14-3-3 target proteins is also conserved over the whole animal kingdom we isolated 14-3-3 binding proteins from Hydra vulgaris using a 14-3-3-affinity column. We identified 23 proteins that covered most of the above-mentioned groups. We also isolated several novel 14-3-3 binding proteins and the Hydra specific secreted fascin-domain-containing protein PPOD. In addition, we demonstrated that one of the 14-3-3 isoforms, 14-3-3 HyA, interacts with one Hydra-Bcl-2 like protein in vitro. Conclusion Our results indicate that 14-3-3 proteins have been ubiquitous signalling components since the start of metazoan evolution. We also discuss the possibility that they are involved in the regulation of cell numbers in response to food supply in Hydra.

  15. Verse letters to T.W. from John Donne: "By you my love is sent".

    Science.gov (United States)

    Klawitter, G

    1992-01-01

    Relying on an audience of one for their impact, the verse letters of John Donne are closer to autobiography than anything else in his poetry. Among the most tender of these lyrics are the verse letters written to a young man named Thomas Woodward, whose older brother was one of Donne's closest friends. Using sexual metaphors, the poems reflect a homoerotic undercurrent and demonstrate affection that most readers of Donne associate only with his heterosexual love poems.

  16. SMI of Bcl-2 TW-37 is active across a spectrum of B-cell tumors irrespective of their proliferative and differentiation status.

    Science.gov (United States)

    Al-Katib, Ayad M; Sun, Yuan; Goustin, Anton Scott; Azmi, Asfar Sohail; Chen, Ben; Aboukameel, Amro; Mohammad, Ramzi M

    2009-02-16

    The Bcl-2 family of proteins is critical to the life and death of malignant B-lymphocytes. Interfering with their activity using small-molecule inhibitors (SMI) is being explored as a new therapeutic strategy for treating B-cell tumors. We evaluated the efficacy of TW-37, a non-peptidic SMI of Bcl-2 against a range spectrum of human B-cell lines, fresh patient samples and animal xenograft models. Multiple cytochemical and molecular approaches such as acridine orange/ethidium bromide assay for apoptosis, co-immunoprecipitation of complexes and western blot analysis, caspase luminescent activity assay and apoptotic DNA fragmentation assay were used to demonstrate the effect of TW-37 on different B-cell lines, patient derived samples, as well as in animal xenograft models. Nanomolar concentrations of TW-37 were able to induce apoptosis in both fresh samples and established cell lines with IC50 in most cases of 165-320 nM. Apoptosis was independent of proliferative status or pathological classification of B-cell tumor. TW-37 was able to block Bim-Bcl-XL and Bim-Mcl-1 heterodimerization and induced apoptosis via activation of caspases -9, -3, PARP and DNA fragmentation. TW-37 administered to tumor-bearing SCID mice led to significant tumor growth inhibition (T/C), tumor growth delay (T-C) and Log10kill, when used at its maximum tolerated dose (40 mg/kg x 3 days) via tail vein. TW-37 failed to induce changes in the Bcl-2 proteins levels suggesting that assessment of baseline Bcl-2 family proteins can be used to predict response to the drug. These findings indicate activity of TW-37 across the spectrum of human B-cell tumors and support the concept of targeting the Bcl-2 system as a therapeutic strategy regardless of the stage of B-cell differentiation.

  17. Hydratools, a MATLAB® based data processing package for Sontek Hydra data

    Science.gov (United States)

    Martini, M.; Lightsom, F.L.; Sherwood, C.R.; Xu, Jie; Lacy, J.R.; Ramsey, A.; Horwitz, R.

    2005-01-01

    The U.S. Geological Survey (USGS) has developed a set of MATLAB tools to process and convert data collected by Sontek Hydra instruments to netCDF, which is a format used by the USGS to process and archive oceanographic time-series data. The USGS makes high-resolution current measurements within 1.5 meters of the bottom. These data are used in combination with other instrument data from sediment transport studies to develop sediment transport models. Instrument manufacturers provide software which outputs unique binary data formats. Multiple data formats are cumbersome. The USGS solution is to translate data streams into a common data format: netCDF. The Hydratools toolbox is written to create netCDF format files following EPIC conventions, complete with embedded metadata. Data are accepted from both the ADV and the PCADP. The toolbox will detect and remove bad data, substitute other sources of heading and tilt measurements if necessary, apply ambiguity corrections, calculate statistics, return information about data quality, and organize metadata. Standardized processing and archiving makes these data more easily and routinely accessible locally and over the Internet. In addition, documentation of the techniques used in the toolbox provides a baseline reference for others utilizing the data.

  18. Suzaku observations of the Hydra A cluster out to the virial radius

    CERN Document Server

    Sato, Takuya; Matsushita, Kyoko; Sakuma, Eri; Sato, Kosuke; Fujita, Yutaka; Okabe, Nobuhiro; Fukazawa, Yasushi; Ichikawa, Kazuya; Kawaharada, Madoka; Nakazawa, Kazuhiro; Ohashi, Takaya; Ota, Naomi; Takizawa, Motokazu; Tamura, Takayuki

    2012-01-01

    We report Suzaku observations of the northern half of the Hydra A cluster out to ~1.4 Mpc, reaching the virial radius. This is the first Suzaku observations of a medium size (kT ~3 keV) cluster out to the virial radius. Two observations were conducted, north-west and north-east offsets, which continue into a filament and a void of the large-scale structure of the Universe, respectively. The X-ray emission and distribution of galaxies elongate towards the filament. The temperature profiles toward the two directions are mostly consistent within error bars and drop to 1.5 keV at 1.5r_500. As observed by Suzaku in hot clusters, the entropy profile becomes flatter beyond r_500 and disagrees with the r^1.1 relation that is expected from accretion shock-heating models. When scaled with average intracluster medium (ICM) temperature, the entropy profiles of clusters observed with Suzaku are universal without dependence on system mass. The hydrostatic mass values toward the void and the filament agree well, and the Nav...

  19. Bringing ATLAS production to HPC resources. A case study with SuperMuc and Hydra

    Energy Technology Data Exchange (ETDEWEB)

    Duckeck, Guenter; Walker, Rodney [LMU Muenchen (Germany); Kennedy, John; Mazzaferro, Luca [RZG Garching (Germany); Kluth, Stefan [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: ATLAS-Collaboration

    2015-07-01

    The possible usage of Supercomputer systems or HPC resources by ATLAS is now becoming viable due to the changing nature of these systems and it is also very attractive due to the need for increasing amounts of simulated data. The ATLAS experiment at CERN will begin a period of high luminosity data taking in 2015. The corresponding need for simulated data might potentially exceed the capabilities of the current Grid infrastructure. ATLAS aims to address this need by opportunistically accessing resources such as cloud and HPC systems. This contribution presents the results of two projects undertaken by LMU/LRZ and MPP/RZG to use the supercomputer facilities SuperMuc (LRZ) and Hydra (RZG). Both are Linux based supercomputers in the 100 k CPU-core category. The integration of such HPC resources into the ATLAS production system poses many challenges. Firstly, established techniques and features of standard WLCG operation are prohibited or much restricted on HPC systems, e.g. Grid middleware, software installation, outside connectivity, etc. Secondly, efficient use of available resources requires massive multi-core jobs, back-fill submission and check-pointing. We discuss the customization of these components and the strategies for HPC usage as well as possibilities for future directions.

  20. [Morpho-functional characteristics of the lingual epithelium after administration of hydra peptide morphogen].

    Science.gov (United States)

    Kulaeva, V V; Bykov, V L

    2007-01-01

    Using histological, morphometric and quantitative histoenzymological methods, the changes of lingual epithelium were studied in 40 outbred albino mice after 5 intraperitoneal injections of 100 micrograms of hydra peptide morphogen (HPM) per 1 kg of body weight. Administration of HPM was found to increase the total thickness of epithelial layer on the dorsal tongue surface in the interpapillary regions, while in the area of filiform papillae these changes were not significant. On the ventral tongue surface HPM induced a marked increase of total thickness of the epithelial layer as compared to that in control animals. Mitotic activity was increased in the epithelium covering the ventral surface and in the interpapillary regions on the dorsal tongue surface. Histoenzymologic study which involved the demonstration of NADH-diaphorase, succinate- and lactate-dehydrogenase (LDH) activities, followed by a cytophotometric evaluation of enzyme activity, has shown a stimulatory effect of HPM on the activity of all the enzymes studied, which was most pronounced in respect to LDH and was maximally expressed on the dorsal tongue surface. These findings collectively suggest that HPM exerts a stimulatory effect on proliferation activity and metabolism of lingual epithelium, which is differentially expressed in its variuoe topographical zones.

  1. BVRI Photometric and Polarimetric studies of W UMa type Eclipsing Binary FO Hydra

    CERN Document Server

    Prasad, Vinod; Patel, Manoj K; Srivastava, D C

    2012-01-01

    We present analysis of optical photometric and polarimetric observations of contact binary system FO Hydra (FO Hya). The computed period of the system is 0.469556+/-0.000003 days. An O-C curve analysis indicates an increase in its period by 5.77x10^{-8} day yr^{-1}. The photometric light curves are analyzed using Wilson-Devinney code (WD). The present analysis shows that FO Hya is a B-subtype of W UMa type contact binary. The radii and mass of primary and secondary components are found, respectively, to be R_1 = 1.62+/-0.03 R_sun and R_2 = 0.91+/-0.02 R_sun, and M_1 = 1.31+/-0.07 M_sun and M_2 = 0.31+/-0.11 M_sun. The light curve shape shows small asymmetries around the primary and secondary maxima. This may be due to the presence of dark spots on the components. The polarimetric observations yield average values of its polarization to be 0.18+/-0.03, 0.15+/-0.03, 0.17+/-0.02 and 0.15+/-0.02 per cent in B, V, R and I bands, respectively. These values are appreciably lower than the typical polarization of W UM...

  2. A textbook example of ram-pressure stripping in the Hydra A/A780 cluster

    Science.gov (United States)

    De Grandi, S.; Eckert, D.; Molendi, S.; Girardi, M.; Roediger, E.; Gaspari, M.; Gastaldello, F.; Ghizzardi, S.; Nonino, M.; Rossetti, M.

    2016-08-01

    In the current epoch, one of the main mechanisms driving the growth of galaxy clusters is the continuous accretion of group-scale halos. In this process, the ram pressure applied by the hot intracluster medium on the gas content of the infalling group is responsible for stripping the gas from its dark-matter halo, which gradually leads to the virialisation of the infalling gas in the potential well of the main cluster. Using deep wide-field observations of the poor cluster Hydra A/A780 with XMM-Newton and Suzaku, we report on the discovery of an infalling galaxy group 1.1 Mpc south of the cluster core. The presence of a substructure is confirmed by a dynamical study of the galaxies in this region. A wake of stripped gas is trailing behind the group over a projected scale of 760 kpc. The temperature of the gas along the wake is constant at kT ~ 1.3 keV, which is about a factor of two less than the temperature of the surrounding plasma. We observe a cold front pointing westwards compared to the peak of the group, which indicates that the group is currently not moving in the direction of the main cluster, but is moving along an almost circular orbit. The overall morphology of the group bears remarkable similarities with high-resolution numerical simulations of such structures, which greatly strengthens our understanding of the ram-pressure stripping process.

  3. The Hydra I cluster core. I. Stellar populations in the cD galaxy NGC 3311

    CERN Document Server

    Barbosa, Carlos Eduardo; Coccato, Lodovico; Hilker, Michael; de Oliveira, Cláudia Mendes; Richtler, Tom

    2016-01-01

    (Abridged for arXiv) The history of the mass assembly of brightest cluster galaxies may be studied by the mapping the stellar populations at large radial distances from the galaxy centre. We provide extended and robust measurements of the stellar population parameters in NGC 3311, the cD galaxy at the centre of the Hydra I cluster and out to three effective radii. Using seven absorption-features defined in the Lick/IDS system and single stellar populations models, we obtained luminosity-weighted ages, metallicities and alpha element abundances. The trends in the Lick indices and the distribution of the stellar population parameters indicate that the stars of NGC 3311 may be divided into two radial regimes, one within and the another beyond one effective radius, $R_e = 8.4$ kpc, similar to the distinction between inner galaxy and external halo derived from the NGC 3311 velocity dispersion profile. The inner galaxy ($R\\leq R_e$) is old (age $\\sim 14$ Gyr), have negative metallicity gradients and positive alpha ...

  4. Fluorescent nanocrystals reveal regulated portals of entry into and between the cells of Hydra.

    Directory of Open Access Journals (Sweden)

    Claudia Tortiglione

    Full Text Available Initially viewed as innovative carriers for biomedical applications, with unique photophysical properties and great versatility to be decorated at their surface with suitable molecules, nanoparticles can also play active roles in mediating biological effects, suggesting the need to deeply investigate the mechanisms underlying cell-nanoparticle interaction and to identify the molecular players. Here we show that the cell uptake of fluorescent CdSe/CdS quantum rods (QRs by Hydra vulgaris, a simple model organism at the base of metazoan evolution, can be tuned by modifying nanoparticle surface charge. At acidic pH, amino-PEG coated QRs, showing positive surface charge, are actively internalized by tentacle and body ectodermal cells, while negatively charged nanoparticles are not uptaken. In order to identify the molecular factors underlying QR uptake at acidic pH, we provide functional evidence of annexins involvement and explain the QR uptake as the combined result of QR positive charge and annexin membrane insertion. Moreover, tracking QR labelled cells during development and regeneration allowed us to uncover novel intercellular trafficking and cell dynamics underlying the remarkable plasticity of this ancient organism.

  5. Fluctuations and symmetry breaking during regeneration of Hydra vulgaris tissue toroids

    CERN Document Server

    Krahe, Michael; Lin, Kao-Nung; Fischer, Julia; Fütterer, Claus

    2012-01-01

    While much is known in single cell mechanics, the mechanics of regeneration of naturally grown tissues and cell assemblies is largely unexplored. We found a symmetry breaking scenario accompanied by shape fluctuations in dissected regenerating Hydra vulgaris tissue tori. A subsequent folding and merging process leads finally to a regenerating spheroid. These phenomena are related to the dynamics of fluorescent beta- and trans-cellular alpha-actin structures. By embedding the tissues in a hydro-gel the fluctuations could be studied over a longer period of time. The power spectrum of the torus-fluctuations shows a non-trivial energy distribution dynamics depending on the gel stiffness. During the transition, many higher modes where found but in the end the 2nd mode wins in most cases. The toroid builds up an uniform alpha-actin ring along the inner edge of the torus. We found this ring in the inner cellular layer to be responsible for the force generation destabilizing the toroid shape. This actin structure is ...

  6. A textbook example of ram-pressure stripping in the Hydra A/A780 cluster

    CERN Document Server

    De Grandi, S; Molendi, S; Girardi, M; Roediger, E; Gaspari, M; Gastaldello, F; Ghizzardi, S; Nonino, M; Rossetti, M

    2016-01-01

    In the current epoch, one of the main mechanisms driving the growth of galaxy clusters is the continuous accretion of group-scale halos. In this process, the ram pressure applied by the hot intracluster medium on the gas content of the infalling group is responsible for stripping the gas from its dark-matter halo, which gradually leads to the virialization of the infalling gas in the potential well of the main cluster. Using deep wide-field observations of the poor cluster Hydra A/A780 with XMM-Newton and Suzaku, we report the discovery of an infalling galaxy group 1.1 Mpc south of the cluster core. The presence of a substructure is confirmed by a dynamical study of the galaxies in this region. A wake of stripped gas is trailing behind the group over a projected scale of 760 kpc. The temperature of the gas along the wake is constant at kT ~ 1.3 keV, which is about a factor of two less than the temperature of the surrounding plasma. We observe a cold front pointing westwards compared to the peak of the group, ...

  7. Cold gas dynamics in Hydra-A: evidence for a rotating disk

    CERN Document Server

    Hamer, S L; Swinbank, A M; Oonk, J B R; Mittal, R; McNamara, B R; Russell, H R; Bremer, M N; Combes, F; Fabian, A C; Nesvadba, N P H; O'Dea, C P; Baum, S A; Salomé, P; Tremblay, G; Donahue, M; Ferland, G J; Sarazin, C L

    2013-01-01

    We present multi-frequency observations of the radio galaxy Hydra-A (3C218) located in the core of a massive, X-ray luminous galaxy cluster. IFU spectroscopy is used to trace the kinematics of the ionised and warm molecular hydrogen which are consistent with a ~ 5 kpc rotating disc. Broad, double-peaked lines of CO(2-1), [CII]157 $\\mu$m and [OI]63 $\\mu$m are detected. We estimate the mass of the cold gas within the disc to be M$_{gas}$ = 2.3 $\\pm$ 0.3 x 10$^9$ M$_{\\odot}$. These observations demonstrate that the complex line profiles found in the cold atomic and molecular gas are related to the rotating disc or ring of gas. Finally, an HST image of the galaxy shows that this gas disc contains a substantial mass of dust. The large gas mass, SFR and kinematics are consistent with the levels of gas cooling from the ICM. We conclude that the cold gas originates from the continual quiescent accumulation of cooled ICM gas. The rotation is in a plane perpendicular to the projected orientation of the radio jets and I...

  8. On the role of corotation radius in the low T/W dynamical instability of differentially rotating stars

    Science.gov (United States)

    Yoshida, Shin'ichirou; Saijo, Motoyuki

    2017-04-01

    We investigate the nature of so-called low T/W dynamical instability in a differentially rotating star, by focusing on the role played by the corotation radius of the unstable oscillation modes. A one-dimensional model of linear perturbation, which neglects dependence of variables on the coordinate along the rotational axis of the star, is solved to obtain stable and unstable eigenmodes. A linear eigenmode having a corotation radius, at which azimuthal pattern speed of the mode coincides with the stellar angular velocity, is categorized to either a complex (growing or damping) mode or a purely real mode belonging to a continuous spectrum of frequency. We compute canonical angular momentum and its flux to study eigenmodes with corotation radius. In a dynamically unstable mode, sound wave transports its angular momentum in such a way that the absolute value of the angular momentum is increased on both sides of the corotation radius. We further evaluate growth of amplitude of reflected sound wave incident to a corotation point, and find that the overreflection of the wave and the trapping of it between the corotation radius and the surface of the star may qualitatively explain dependences of eigenfrequencies on the stellar differential rotation. The results suggest that the low T/W instability may be caused by overreflection of sound waves trapped mainly between the surface of the star and a corotation radius.

  9. Genome sequence of Ensifer sp. TW10; a Tephrosia wallichii (Biyani) microsymbiont native to the Indian Thar Desert.

    Science.gov (United States)

    Tak, Nisha; Gehlot, Hukam S; Kaushik, Muskan; Choudhary, Sunil; Tiwari, Ravi; Tian, Rui; Hill, Yvette; Bräu, Lambert; Goodwin, Lynne; Han, James; Liolios, Konstantinos; Huntemann, Marcel; Palaniappan, Krishna; Pati, Amrita; Mavromatis, Konstantinos; Ivanova, Natalia; Markowitz, Victor; Woyke, Tanja; Kyrpides, Nikos; Reeve, Wayne

    2013-12-20

    Ensifer sp. TW10 is a novel N2-fixing bacterium isolated from a root nodule of the perennial legume Tephrosia wallichii Graham (known locally as Biyani) found in the Great Indian (or Thar) desert, a large arid region in the northwestern part of the Indian subcontinent. Strain TW10 is a Gram-negative, rod shaped, aerobic, motile, non-spore forming, species of root nodule bacteria (RNB) that promiscuously nodulates legumes in Thar Desert alkaline soil. It is fast growing, acid-producing, and tolerates up to 2% NaCl and capable of growth at 40(o)C. In this report we describe for the first time the primary features of this Thar Desert soil saprophyte together with genome sequence information and annotation. The 6,802,256 bp genome has a GC content of 62% and is arranged into 57 scaffolds containing 6,470 protein-coding genes, 73 RNA genes and a single rRNA operon. This genome is one of 100 RNB genomes sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project.

  10. The Radial Distribution of H2 and CO in TW Hya as Revealed by Resolved ALMA Observations of CO Isotopologues

    CERN Document Server

    Schwarz, Kamber R; Cleeves, L Ilsedore; Blake, Geoffrey A; Zhang, Ke; Öberg, Karin I; van Dishoeck, Ewine F; Qi, Chunhua

    2016-01-01

    CO is widely used as a tracer of molecular gas. However, there is now mounting evidence that gas phase carbon is depleted in the disk around TW Hya. Previous efforts to quantify this depletion have been hampered by uncertainties regarding the radial thermal structure in the disk. Here we present resolved ALMA observations of 13CO 3-2, C18O 3-2, 13CO 6-5, and C18O 6-5 emission in TW Hya, which allow us to derive radial gas temperature and gas surface density profiles, as well as map the CO abundance as a function of radius. These observations provide a measurement of the surface CO snowline at ~30 AU and show evidence for an outer ring of CO emission centered at 53 AU, a feature previously seen only in less abundant species. Further, the derived CO gas temperature profile constrains the freeze-out temperature of CO in the warm molecular layer to < 21 K. Combined with the previous detection of HD 1-0, these data constrain the surface density of the warm H2 gas in the inner ~30 AU. We find that CO is depleted...

  11. Biografia nieobecna. Wokół życia i twórczości Ireneusza Plater-Zyberka

    Directory of Open Access Journals (Sweden)

    Robert Zawisza

    2014-12-01

    Full Text Available An Absent Biography. About the life and work of Ireneusz Plater-Zyberk Ireneusz Plater-Zyberk (1896–1946, was a writer and a film producer, adventurer and gallant. His life is an incredible story of the disabled individual who succeeded in an amazing career. Plater-Zyberk was born in a wealthy landowning family who lived at the estate of Vabole in Latvia. He was born without hands and at that time, due to his disability, was classified as "margins of society." Thanks to perseverance and commitment of his mother, he graduated as an extern student from high school in Warsaw, Poland. His career  includes Life without Hands, memories,  and two novels. He was a co-author of first movie in Poland with stunt effects Dead Node (1927, which unfortunately wasn’t preserved. Also, he was recognized as a documentary creator as well as an initiator of film production regulations.   Biografia nieobecna. Wokół życia i twórczości Ireneusza Plater-Zyberka Ireneusz Plater-Zyberk (1896 lub 1897–1946 był literatem i twórcą filmowym, nieco awanturnikiem i bawidamkiem. Jego postać to niezwykły przykład niepełnosprawnego, który osiągnął w dwudziestoleciu międzywojennym znaczącą karierę. Ireneusz Plater-Zyberk pochodził z zamożnej rodziny ziemiańskiej, zamieszkałej w majątku Wabol na Łotwie. Urodził się bez rąk i w ówczesnej rzeczywistości miał pozostać na marginesie społeczeństwa. Dzięki wytrwałości matki udało mu się ukończyć jako ekstern gimnazjum w Warszawie. W swoim dorobku ma wspomnienia Życie bez rąk oraz dwie powieści. Ważną rolę odegrał Plater jako scenarzysta i reżyser, był m.in. współtwórcą pierwszego polskiego filmu z efektami kaskaderskimi „Martwy węzeł” (1927. Miał on również ogromne zasługi jako twórca filmów dokumentalnych i jednocześnie inspirator zmian w prawodawstwie dotyczącym produkcji filmowej. Tłem jego twórczości pisarskiej jest burzliwe i pełne przygód

  12. Comparative analysis of septic injury-inducible genes in phylogenetically distant model organisms of regeneration and stem cell research, the planarian Schmidtea mediterranea and the cnidarian Hydra vulgaris

    Directory of Open Access Journals (Sweden)

    Vilcinskas Andreas

    2008-04-01

    Full Text Available Abstract Background The planarian Schmidtea mediterranea and the cnidarian Hydra vulgaris have emerged as valuable model organisms in regeneration and stem cell research because of their prominent ability to regenerate a complete organism from any small body fragment. Under natural conditions wounding may result from predator attacks. These injuries open their innermost to a wide array of microbes present in the environment. Therefore, we established the hypothesis that regeneration processes may be linked to or at least accompanied by innate immune responses. In order to screen for septic wounding inducible genes we dissected individuals using a scalpel in the presence of a crude bacterial lipopolysaccharide preparation that is commonly used to elicit innate immune responses in animals and applied the suppression subtractive hybridization technique that selectively amplifies cDNAs of differentially expressed genes. Results This analysis revealed the induced expression of 27 genes in immune challenged Schmidtea and 35 genes in immune challenged Hydra. Identified genes from both animals encode proteins that share sequence similarities with potential homologues from other organisms known to be involved in signaling (e.g. calreticulin in Schmidtea and major vault protein in Hydra, stress responses (e.g. Hsp20 in Schmidtea and a PRP19/PSO4 DNA repair protein in Hydra, or to represent potential antimicrobial effectors (e.g. perforin-like protein in Schmidtea and PR-1-like protein and neutrophil cytosolic factor 1 in Hydra. As expected, septic wounding also induces expression of genes in Schmidtea and Hydra potentially involved in tissue remodeling associated with regeneration processes (e.g. matrix metalloproteinase in Schmidtea and a potential von Willebrand factor in Hydra. Conclusion We identified numerous immune-inducible genes in Hydra and Schmidtea that show a similar distribution corresponding to their physiological roles, although lineages of

  13. 更亮更美更平价投影机——Epson EMP-S1H/EMP-TW10H

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Epson最新推出的两都家用入门级投影机——EMP-S1H及EMP-TW10H,都是上一代EMP-S1和EMP-TW10的加强版.同时加强了显示的亮度与对比度。奠中.EMP-S1H拥有较亮的1,400流明亮度及500:1的对比度;而EMP-TW10H则拥有鞍高显示品质的1,200流明及800:1对比度。而最重要的.就是两机分别都比上一

  14. 更亮更美更平价投影机 Epson EMP-S1H / EMP-TW10H

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Epson最新推出的两部家用入门级投影机——EMP-SIH及EMP-TW10H,都是一代EMP-S1和EMP-TW10的加强版,同时加强了显示的亮度与对比度,其中,EMP-S1H拥有较高的1.400流明亮度及500:1的对比度;而EMP-TW10H则拥有较高显示器质的1.200流明及800:1对比度。而最重要的,就是两机分别都比上一

  15. Volatile-carbon locking and release in protoplanetary disks. A study of TW Hya and HD 100546

    Science.gov (United States)

    Kama, M.; Bruderer, S.; van Dishoeck, E. F.; Hogerheijde, M.; Folsom, C. P.; Miotello, A.; Fedele, D.; Belloche, A.; Güsten, R.; Wyrowski, F.

    2016-08-01

    Aims: The composition of planetary solids and gases is largely rooted in the processing of volatile elements in protoplanetary disks. To shed light on the key processes, we carry out a comparative analysis of the gas-phase carbon abundance in two systems with a similar age and disk mass, but different central stars: HD 100546 and TW Hya. Methods: We combine our recent detections of C0 in these disks with observations of other carbon reservoirs (CO, C+, C2H) and gas-mass and warm-gas tracers (HD, O0), as well as spatially resolved ALMA observations and the spectral energy distribution. The disks are modelled with the DALI 2D physical-chemical code. Stellar abundances for HD 100546 are derived from archival spectra. Results: Upper limits on HD emission from HD 100546 place an upper limit on the total disk mass of ≤0.1 M⊙. The gas-phase carbon abundance in the atmosphere of this warm Herbig disk is, at most, moderately depleted compared to the interstellar medium, with [C]/[H]gas = (0.1-1.5) × 10-4. HD 100546 itself is a λBoötis star, with solar abundances of C and O but a strong depletion of rock-forming elements. In the gas of the T Tauri disk TW Hya, both C and O are strongly underabundant, with [C]/[H]gas = (0.2-5.0) × 10-6 and C / O > 1. We discuss evidence that the gas-phase C and O abundances are high in the warm inner regions of both disks. Our analytical model, including vertical mixing and a grain size distribution, reproduces the observed [C]/[H]gas in the outer disk of TW Hya and allows to make predictions for other systems. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 093.C-0926, 093.F-0015, 077.D-0092, 084.A-9016, and 085.A-9027.Spectra and models are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A83

  16. Coordinated modulation of cellular signaling through ligand-gated ion channels in Hydra vulgaris (Cnidaria, Hydrozoa).

    Science.gov (United States)

    Pierobon, Paola

    2012-01-01

    Cnidarians lack well developed organs, but they have evolved the molecular and cellular components needed to assemble a nervous system. The apparent 'simplicity' of the cnidarian nervous net does not occur at the cellular level, but rather in the organisation of conducting systems. Cnidarian neurons are in fact electrically excitable, show the typical extended morphology and are connected by chemical synapses or gap junctions. They have been regarded as peptidergic, given the wealth of neuropeptides generally distributed along neurites and in cell bodies, supporting the hypothesis of a modulatory role in neurotransmission. However, the presence of clear-cored, as well as dense-cored synaptic vesicles in cnidarian neurons suggests both fast and slow synaptic transmission mechanisms. In fact, biochemical and functional evidence indicates that classical neurotransmitters and their metabolic partners are present in cnidarian tissues, where they are involved in coordinating motility and behavior. We have identified and characterized in Hydra tissues receptors to the inhibitory and excitatory amino acid neurotransmitters, GABA, glycine and NMDA, that are similar to mammalian ionotropic receptors in terms of their biochemical and pharmacological properties. These receptors appear to regulate pacemaker activities and their physiological correlates; in the live animal, they also affect feeding behavior, namely the duration and termination of the response elicited by reduced glutathione, with opposite actions of GABA and glycine or NMDA, respectively. These results suggest that modulation of cellular signaling through ligand-gated-ion channels is an ancient characteristic in the animal kingdom, and that the pharmacological properties of these receptors have been highly conserved during evolution.

  17. Generation of sub-three-cycle, 16 TW light pulses by using noncollinear optical parametric chirped-pulse amplification.

    Science.gov (United States)

    Herrmann, Daniel; Veisz, Laszlo; Tautz, Raphael; Tavella, Franz; Schmid, Karl; Pervak, Vladimir; Krausz, Ferenc

    2009-08-15

    We present a two-stage noncollinear optical parametric chirped-pulse amplification system that generates 7.9 fs pulses containing 130 mJ of energy at an 805 nm central wavelength and 10 Hz repetition rate. These 16 TW light pulses are compressed to within 5% of their Fourier limit and are carefully characterized by the use of home-built pulse diagnostics. The contrast ratio before the main pulse has been measured as 10(-4), 10(-8), and 10(-11) at t=-3.3 ps, t=-5 ps, and t=-30 ps, respectively. This source allows for experiments in a regime of relativistic light-matter interactions and attosecond science.

  18. Data on the DNA damaging and mutagenic potential of the BH3-mimetics ABT-263/Navitoclax and TW-37.

    Science.gov (United States)

    Green, Maja M; Shekhar, Tanmay M; Hawkins, Christine J

    2016-03-01

    Unfortunately, the mutagenic activities of chemotherapy and radiotherapy can provoke development of therapy-induced malignancies in cancer survivors. Non-mutagenic anti-cancer therapies may be less likely to trigger subsequent malignant neoplasms. Here we present data regarding the DNA damaging and mutagenic potential of two drugs that antagonize proteins within the Bcl-2 family: ABT-263/Navitoclax and TW-37. Our data reveal that concentrations of these agents that stimulated Bax/Bak-dependent signaling provoked little DNA damage and failed to trigger mutations in surviving cells. The data supplied in this article is related to the research work entitled "Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells" [1].

  19. First electrons from the new 220 TW Frascati Laser for Acceleration and Multidisciplinary Experiments (FLAME) at Frascati National Laboratories (LNF)

    Energy Technology Data Exchange (ETDEWEB)

    Levato, T., E-mail: tadzio.levato@lnf.infn.it [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Calvetti, M. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); University of Florence, Department of Physics (Italy); Anelli, F. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Batani, D.; Benocci, R. [University of Milano Bicocca, Department of Physics (Italy); Cacciotti, L. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Cecchetti, C.A. [Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); INFN, Sect. of Pisa (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Cerafogli, O.; Chimenti, P.; Clozza, A. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Drenska, N. [University of Roma La Sapienza (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Esposito, A. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Faccini, R. [University of Roma La Sapienza (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Fioravanti, S. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Gamucci, A. [Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); INFN, Sect. of Pisa (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Gatti, C. [University of Roma La Sapienza (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Giulietti, A. [Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); Giulietti, D. [University of Pisa, Department of Physics (Italy); Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); INFN, Sect. of Pisa (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Labate, L. [Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); INFN, Sect. of Pisa (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Lollo, V. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); and others

    2013-08-21

    A new era of laser based plasma accelerators is emerging following the commissioning of many high power laser facilities around the world. Extremely short (tens of fs) laser pulses with energy of multi-joules level are available at these newly built facilities. Here we describe the new 220 TW FLAME facility. In particular we discuss the laser system general layout, the main measurements on the laser pulse parameters, the underground target area. Finally we give an overview of the first results of the Self-Injection Test Experiment (SITE), obtained at a low laser energy. This initial low laser energy experimental campaign was necessary for the validation of the radio-protection shielding (Esposito, 2011 [1]) we discuss here. With respect to our preliminary configuration, with a pulse duration of 30 fs and a focusing optic of F/15, we discuss here the minimum laser energy requirements for electron acceleration and the forward transmitted optical radiation.

  20. Steady γ-Ray Effects on the Performance of PPP-BOTDA and TW-COTDR Fiber Sensing

    Directory of Open Access Journals (Sweden)

    Isabelle Planes

    2017-02-01

    Full Text Available We investigated the evolution of the performances of Pulse Pre Pump-Brillouin Time Domain Analysis (PPP-BOTDA and Tunable Wavelength Coherent Optical Time Domain Reflectometry (TW-COTDR fiber-based temperature and strain sensors when the sensing optical fiber is exposed to two γ-ray irradiation conditions: (i at room temperature and a dose rate of 370 Gy(SiO2/h up to a total ionizing dose (TID of 56 kGy; (ii at room temperature and a dose rate of 25 kGy(SiO2/h up to a TID of 10 MGy. Two main different classes of single-mode optical fibers have been tested in situ, radiation-tolerant ones: fluorine-doped or nitrogen-doped core fibers, as well as Telecom-grade germanosilicate ones. Brillouin and Rayleigh Sensitivities of N-Doped fibers were not reported yet, and these characterizations pave the way for a novel and alternative sensing scheme. Moreover, in these harsh conditions, our results showed that the main parameter affecting the sensor sensitivity remains the Radiation Induced Attenuation (RIA at its operation wavelength of 1550 nm. RIA limits the maximal sensing range but does not influence the measurement uncertainty. F-doped fiber is the most tolerant against RIA with induced losses below 8 dB/km after a 56 kGy accumulated dose whereas the excess losses of other fibers exceed 22 dB/km. Both Rayleigh and Brillouin signatures that are exploited by the PPP-BOTDA and the TW-COTDR remain unchanged (within our experimental uncertainties. The strain and temperature coefficients of the various fibers under test are not modified by radiations, at these dose/dose rate levels. Consequently, this enables the design of a robust strain and temperature sensing architecture for the monitoring of radioactive waste disposals.

  1. Steady γ-Ray Effects on the Performance of PPP-BOTDA and TW-COTDR Fiber Sensing

    Science.gov (United States)

    Planes, Isabelle; Girard, Sylvain; Boukenter, Aziz; Marin, Emmanuel; Delepine-Lesoille, Sylvie; Marcandella, Claude; Ouerdane, Youcef

    2017-01-01

    We investigated the evolution of the performances of Pulse Pre Pump-Brillouin Time Domain Analysis (PPP-BOTDA) and Tunable Wavelength Coherent Optical Time Domain Reflectometry (TW-COTDR) fiber-based temperature and strain sensors when the sensing optical fiber is exposed to two γ-ray irradiation conditions: (i) at room temperature and a dose rate of 370 Gy(SiO2)/h up to a total ionizing dose (TID) of 56 kGy; (ii) at room temperature and a dose rate of 25 kGy(SiO2)/h up to a TID of 10 MGy. Two main different classes of single-mode optical fibers have been tested in situ, radiation-tolerant ones: fluorine-doped or nitrogen-doped core fibers, as well as Telecom-grade germanosilicate ones. Brillouin and Rayleigh Sensitivities of N-Doped fibers were not reported yet, and these characterizations pave the way for a novel and alternative sensing scheme. Moreover, in these harsh conditions, our results showed that the main parameter affecting the sensor sensitivity remains the Radiation Induced Attenuation (RIA) at its operation wavelength of 1550 nm. RIA limits the maximal sensing range but does not influence the measurement uncertainty. F-doped fiber is the most tolerant against RIA with induced losses below 8 dB/km after a 56 kGy accumulated dose whereas the excess losses of other fibers exceed 22 dB/km. Both Rayleigh and Brillouin signatures that are exploited by the PPP-BOTDA and the TW-COTDR remain unchanged (within our experimental uncertainties). The strain and temperature coefficients of the various fibers under test are not modified by radiations, at these dose/dose rate levels. Consequently, this enables the design of a robust strain and temperature sensing architecture for the monitoring of radioactive waste disposals. PMID:28218652

  2. Molecular cloning, sequence analysis, prokaryotic expression, and function prediction of foot-specific peroxidase in Hydra magnipapillata Chinese strain.

    Science.gov (United States)

    Pan, H C; Yang, H Q; Zhao, F X; Qian, X C

    2014-08-28

    The cDNA sequence of foot-specific peroxidase PPOD1 from the Chinese strain of Hydra magnipapillata was cloned by reverse transcription-polymerase chain reaction. The cDNA sequence contained a coding region with an 873-bp open reading frame, a 31-bp 5'-untranslated region, and a 36-bp 3'-untranslated region. The structure prediction results showed that PPOD1 contains 10.34% of α-helix, 38.62% of extended strand, 12.41% of β-turn, and 38.62% of random coil. The structural core was α-helix at the N terminus. The GenBank protein blast server showed that PPOD1 contains 2 fascin-like domains. In addition, high-level PPOD1 activity was only present in the ectodermal epithelial cells located on the edge of the adhesive face of the basal disc, and that these cells extended lamellipodia and filopodia when the basal disc was tightly attached to a glass slide. The fascin-like domains of Hydra PPOD1 might contribute to the bundling of the actin filament of these cells, and hence, the formation of filopodia. In conclusion, these cells might play an important role in strengthening the adsorbability of the basal disc to substrates.

  3. Loss of neurogenesis in Hydra leads to compensatory regulation of neurogenic and neurotransmission genes in epithelial cells.

    Science.gov (United States)

    Wenger, Y; Buzgariu, W; Galliot, B

    2016-01-05

    Hydra continuously differentiates a sophisticated nervous system made of mechanosensory cells (nematocytes) and sensory-motor and ganglionic neurons from interstitial stem cells. However, this dynamic adult neurogenesis is dispensable for morphogenesis. Indeed animals depleted of their interstitial stem cells and interstitial progenitors lose their active behaviours but maintain their developmental fitness, and regenerate and bud when force-fed. To characterize the impact of the loss of neurogenesis in Hydra, we first performed transcriptomic profiling at five positions along the body axis. We found neurogenic genes predominantly expressed along the central body column, which contains stem cells and progenitors, and neurotransmission genes predominantly expressed at the extremities, where the nervous system is dense. Next, we performed transcriptomics on animals depleted of their interstitial cells by hydroxyurea, colchicine or heat-shock treatment. By crossing these results with cell-type-specific transcriptomics, we identified epithelial genes up-regulated upon loss of neurogenesis: transcription factors (Dlx, Dlx1, DMBX1/Manacle, Ets1, Gli3, KLF11, LMX1A, ZNF436, Shox1), epitheliopeptides (Arminins, PW peptide), neurosignalling components (CAMK1D, DDCl2, Inx1), ligand-ion channel receptors (CHRNA1, NaC7), G-Protein Coupled Receptors and FMRFRL. Hence epitheliomuscular cells seemingly enhance their sensing ability when neurogenesis is compromised. This unsuspected plasticity might reflect the extended multifunctionality of epithelial-like cells in early eumetazoan evolution.

  4. Genome-wide screening reveals the emergence and divergence of RTK homologues in basal Metazoan Hydra magnipapillata

    Indian Academy of Sciences (India)

    P C Reddy; Salil S Bidaye; Surendra Ghaskadbi

    2011-06-01

    Receptor tyrosine kinases (RTKs) are key components of cell–cell signalling required for growth and development of multicellular organisms. It is therefore likely that the divergence of RTKs and associated components played a significant role in the evolution of multicellular organisms. We have carried out the present study in hydra, a diploblast, to investigate the divergence of RTKs after parazoa and before emergence of triploblast phyla. The domain-based screening using Hidden Markov Models (HMMs) for RTKs in Genomescan predicted gene models of the Hydra magnipapillata genome resulted in identification of 15 RTKs. These RTKs have been classified into eight families based on domain architecture and homology. Only 5 of these RTKs have been previously reported and a few of these have been partially characterized. A phylogeny-based analysis of these predicted RTKs revealed that seven subtype duplications occurred between `parazoan–eumetazoan split’ and `diploblast–triploblast split’ in animal phyla. These results suggest that most of the RTKs evolved before the radiata–bilateria divergence during animal evolution.

  5. A Multi-Year Plan for Enhancing Turbulence Modeling in Hydra-TH Revised and Updated Version 2.0

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Thomas M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Berndt, Markus [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baglietto, Emilio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Magolan, Ben [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2015-10-01

    The purpose of this report is to document a multi-year plan for enhancing turbulence modeling in Hydra-TH for the Consortium for Advanced Simulation of Light Water Reactors (CASL) program. Hydra-TH is being developed to the meet the high- fidelity, high-Reynolds number CFD based thermal hydraulic simulation needs of the program. This work is being conducted within the thermal hydraulics methods (THM) focus area. This report is an extension of THM CASL milestone L3:THM.CFD.P10.02 [33] (March, 2015) and picks up where it left off. It will also serve to meet the requirements of CASL THM level three milestone, L3:THM.CFD.P11.04, scheduled for completion September 30, 2015. The objectives of this plan will be met by: maturation of recently added turbulence models, strategic design/development of new models and systematic and rigorous testing of existing and new models and model extensions. While multi-phase turbulent flow simulations are important to the program, only single-phase modeling will be considered in this report. Large Eddy Simulation (LES) is also an important modeling methodology. However, at least in the first year, the focus is on steady-state Reynolds Averaged Navier-Stokes (RANS) turbulence modeling.

  6. Transitioning from microbiome composition to microbial community interactions: the potential of the metaorganism Hydra as an experimental model

    Directory of Open Access Journals (Sweden)

    Peter Deines

    2016-10-01

    Full Text Available Animals are home to complex microbial communities, which are shaped through interactions within the community, interactions with the host, and through environmental factors. The advent of high-throughput sequencing methods has led to novel insights in changing patterns of community composition and structure. However, deciphering the different types of interactions among community members, with their hosts and their interplay with their environment is still a challenge of major proportion. The emerging fields of synthetic microbial ecology and community systems biology have the potential to decrypt these complex relationships. Studying host-associated microbiota across multiple spatial and temporal scales will bridge the gap between individual microorganism studies and large-scale whole community surveys. Here, we discuss the unique potential of Hydra as an emerging experimental model in microbiome research. Through in vivo, in vitro, and in silico approaches the interaction structure of host-associated microbial communities and the effects of the host on the microbiota and its interactions can be disentangled. Research in the model system Hydra can unify disciplines from molecular genetics to ecology, opening up the opportunity to discover fundamental rules that govern microbiome community stability.

  7. Immagine della crisi / Crisi dell'immagine. Critica all'egemonia culturale del realismo e diritto all'opacità in Hydra Decapita (2011, un film saggio di The Otolith Group

    Directory of Open Access Journals (Sweden)

    Beatrice Ferrara

    2015-12-01

    Full Text Available This article reflects on the ways in which the relation between crisis and imaginary is articulated in Hydra Decapita, a 2011 essay-film by the British art collective The Otolith Group. Hydra Decapita is an imaged-based reflection arguing for the biopolitical character of the global economic crisis erupted in 2008 and of its representations in the media. By deploying a Cultural Studies-oriented interdisciplinary approach to the artwork – drawing its methodology from visual studies, critical theory and post-colonial studies – the article interrogates the limits and potentialities of Hydra Decapita’s conceptual kernel and aesthetic language.

  8. IMMUNOLOGICAL STUDIES OF THE MULTIGLYCOSIDES OF TRIPTERYGIUM WILFORDII (GTW) AND AN ACTIVE COMPOUND (TW15) ISOLATED FROM THE PLANT

    Institute of Scientific and Technical Information of China (English)

    ZENGHai-Qun; WUYu-Lin; HUYan-Zhong; QIAi-Ping; QIANShao-Zhen

    1989-01-01

    GTW have been shown to cause reversible infertility both in male rats and in men. Very recently, it was reported that a compound isolated from GTW, TW15 (provided by China Pharmae. Univ. and Brit. Columbia Univ. Canada), could also cause infertility in male

  9. Reference values of differences between TW3-C RUS and TW3-C Carpal bone ages of children from five cities of China%中国五城市儿童手腕部桡、尺、掌指骨骨龄与腕骨骨龄差异参考值

    Institute of Scientific and Technical Information of China (English)

    张绍岩; 刘丽娟; 韩一三; 刘刚; 马振国; 沈勋章; 许瑞龙; 花纪青

    2008-01-01

    目的 观察中国城市儿童手腕部桡、尺、掌指骨骨龄与腕骨骨龄差异,为临床应用提供参考.方法 抽取上海、广州、温州、大连、石家庄5城市汉族健康儿童9408名,男5066名,女4342名,年龄1.5~13.5岁.采用桡、尺、掌指骨(BUS)骨龄标准(TW3-C RUS)和腕骨(Carpal)骨龄标准(TW3-C Carpal),分别评价儿童的桡、尺、掌指骨骨龄和腕骨骨龄.采用Box-Cox幂指数分布模型(Box-Cox power exponential distribution,BCPE)建立TW3-CRUS与TW3-C Carpal骨龄差值的Z分值曲线评价图表,以Q检验和拟合的百分位数曲线下样本例数的百分数检验BCPE模型的拟合优度.结果男2.0~13.5岁、女1.5~11.5岁,各年龄组TW3-CBUS与TW3-C Carpal骨龄差值的平均数均接近于零,男童平均数范围在-0.19~0.17岁,女童平均数范围在-0.12~0.13岁;男童年龄组骨龄差值的标准差在0.47~1.01岁之间,达最大标准差时4.5岁;女童骨龄差值的标准差在0.49~0.82岁之间,达最大标准差时3.5岁.经Q检验,选择出了男女儿童骨龄差值BCPE模型,所拟合的百分位数曲线下样本例数的百分数与其理论百分位相差很小,除女第90百分位数相差1.00%外,均在0.66%以下.结论 男女儿童TW3-C RUS与TW3-CCarpal骨龄差值随年龄而增加,分别在男4.5岁和女3.5岁左右达到最大,其后逐渐下降至腕骨发育成熟.但变异程度存在性别差异,男性大于女性,10岁后性别差异减小.%Objective The determination of skeletal maturity has an important role in pediatricclinical practice, especially in relation to endocrinological problems and growth disorders, and it is frequentlyuseful in diagnosis and monitoring treatment. It has been suggested that the difference between radius, ulnaand short bonse (RUS) and carpal may be of differential diagnostic significance. However, no data oncomparison among bone ages of Chinese children are available. The differences between TW3-Chinese RUS(TW3-C BUS) and

  10. Young Market: Young Consumers

    Institute of Scientific and Technical Information of China (English)

    Shang Lin'aiyi

    2009-01-01

    @@ This young generation enjoys a staggering amount of purchasing power in China.That's because the population of young consumers in China is massive. They were born after China instituted its one-child policy in the late 1970s and grew up in the context of China launching its economic reforms and opening up to the world outside.

  11. The Hydra I cluster core. I. Stellar populations in the cD galaxy NGC 3311

    Science.gov (United States)

    Barbosa, C. E.; Arnaboldi, M.; Coccato, L.; Hilker, M.; Mendes de Oliveira, C.; Richtler, T.

    2016-05-01

    Context. The history of the mass assembly of brightest cluster galaxies may be studied by mapping the stellar populations at large radial distances from the galaxy centre, where the dynamical times are long and preserve the chemodynamical signatures of the accretion events. Aims: We provide extended and robust measurements of the stellar population parameters in NGC 3311, the cD galaxy at the centre of the Hydra I cluster, and out to three effective radii. We wish to characterize the processes that drove the build-up of the stellar light at all these radii. Methods: We obtained the spectra from several regions in NGC 3311 covering an area of ~3 arcmin2 in the wavelength range 4800 ≲ λ(Å) ≲ 5800, using the FORS2 spectrograph at the Very Large Telescope in the MXU mode. We measured the equivalent widths of seven absorption-features defined in the Lick/IDS system, which were modelled by single stellar populations, to provide luminosity-weighted ages, metallicities, and alpha element abundances. Results: The trends in the Lick indices and the distribution of the stellar population parameters indicate that the stars of NGC 3311 may be divided in two radial regimes, one within and the another beyond one effective radius, Re = 8.4 kpc, similar to the distinction between the inner galaxy and the external halo derived from the NGC 3311 velocity dispersion profile. The inner galaxy (R ≤ Re) is old (age ~14 Gyr), has negative metallicity gradients and positive alpha element gradients. The external halo is also very old, but has a negative age gradient. The metal and element abundances of the external halo both have a large scatter, indicating that stars from a variety of satellites with different masses have been accreted. The region in the extended halo associated with the off-centred envelope at 0°parent galaxies, either disks with truncated star formation, or the outer regions of early-type galaxies. Late mass accretion at large radii is now coming from the tidal

  12. An orbital period investigation of the Algol-type eclipsing binary VW Hydrae

    Institute of Scientific and Technical Information of China (English)

    Jia Zhang; Sheng-Bang Qian; Boonrucksar Soonthornthum

    2009-01-01

    Orbital period variations of the Algol-type eclipsing binary, VW Hydrae, are analyzed based on one newly determined eclipse time and the other times of light minima collected from the literature. It is discovered that the orbital period shows a continuous increase at a rate of dP/dt = +6.34×10-7 d yr-1 while it undergoes a cyclic change with an amplitude of 0.0639 d and a period of 51.5 yr. After the long-term period increase and the large-amphtude period oscillation were subtracted from the O-C curve, the residuals of the photoelectric and CCD data indicate a small-amplitude cyclic variation with a period of 8.75 yr and a small amplitude of 0.0048d. The continuous period increase indicates a conservative mass transfer at a rate of dM2/dt = 7.89×10-8 M⊙ yr-1 from the secondary to the primary. The period increase may be caused by a combination of the mass transfer from the secondary to the primary and the angular momentum transfer from the binary system to the circumbinary disk. The two cyclic period oscillations can be explained by light-travel time effects via the presence of additional bodies. The small-amplitude periodic change indicates the existence of a less massive component with mass M3 > 0.53 M⊙, while the large-amplitude one is caused by the presence of a more massive component with mass M4 > 2.84 M⊙. The ultraviolet source in the system reported by Kviz & Rufener (1987) may be one of the additional components, and it is possible that the more massive one may be an unseen neutron star or black hole. The rapid period increase and the possibility of the presence of two additional components in the binary make it a very interesting system to study. New photometric and high-resolution spectroscopic observations and a detailed investigation of those data are required in the future.

  13. Constraints on the gamma-ray emission from the cluster-scale AGN outburst in the Hydra A galaxy cluster

    Science.gov (United States)

    HESS Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker, J.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Cologna, G.; Conrad, J.; Couturier, C.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Gérard, L.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Göring, D.; Grondin, M.-H.; Häffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Laffon, H.; Lamanna, G.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.; Ali, M. O.

    2012-09-01

    Context. In some galaxy clusters, powerful active galactic nuclei (AGN) have blown bubbles with cluster scale extent into the ambient medium. The main pressure support of these bubbles is not known to date, but cosmic rays are a viable possibility. For such a scenario copious gamma-ray emission is expected as a tracer of cosmic rays from these systems. Aims: Hydra A, the closest galaxy cluster hosting a cluster scale AGN outburst, located at a redshift of 0.0538, is investigated for being a gamma-ray emitter with the High Energy Stereoscopic System (H.E.S.S.) array and the Fermi Large Area Telescope (Fermi-LAT). Methods: Data obtained in 20.2 h of dedicated H.E.S.S. observations and 38 months of Fermi-LAT data, gathered by its usual all-sky scanning mode, have been analyzed to search for a gamma-ray signal. Results: No signal has been found in either data set. Upper limits on the gamma-ray flux are derived and are compared to models. These are the first limits on gamma-ray emission ever presented for galaxy clusters hosting cluster scale AGN outbursts. Conclusions: The non-detection of Hydra A in gamma-rays has important implications on the particle populations and physical conditions inside the bubbles in this system. For the case of bubbles mainly supported by hadronic cosmic rays, the most favorable scenario, which involves full mixing between cosmic rays and embedding medium, can be excluded. However, hadronic cosmic rays still remain a viable pressure support agent to sustain the bubbles against the thermal pressure of the ambient medium. The largest population of highly-energetic electrons, which are relevant for inverse-Compton gamma-ray production is found in the youngest inner lobes of Hydra A. The limit on the inverse-Compton gamma-ray flux excludes a magnetic field below half of the equipartition value of 16 μG in the inner lobes.

  14. The Far-Ultraviolet Spectra of TW Hya. II. Models of H2 Fluorescence in a Disk

    CERN Document Server

    Herczeg, G J; Linsky, J L; Valenti, J A; Johns-Krull, C M; Herczeg, Gregory J.; Wood, Brian E.; Linsky, Jeffrey L.; Valenti, Jeff A.; Johns-Krull, Chris M.

    2004-01-01

    We measure the temperature of warm gas at planet-forming radii in the disk around the classical T Tauri star (CTTS) TW Hya by modelling the H2 fluorescence observed in HST/STIS and FUSE spectra. Strong Ly-alpha emission irradiates a warm disk surface within 2 AU of the central star and pumps certain excited levels of H2. We simulate a 1D plane-parallel atmosphere to estimate fluxes for the 140 observed H2 emission lines and to reconstruct the Ly-alpha emission profile incident upon the warm H2. The excitation of H2 can be determined from relative line strengths by measuring self-absorption in lines with low-energy lower levels, or by reconstructing the Ly-alpha profile incident upon the warm H2 using the total flux from a single upper level and the opacity in the pumping transition. Based on those diagnostics, we estimate that the warm disk surface has a column density of log N(H2)=18.5^{+1.2}_{-0.8}, a temperature T=2500^{+700}_{-500} K, and a filling factor of H2, as seen by the source of Ly-alpha emission,...

  15. Steepening of the 820 micron continuum surface-brightness profile signals dust evolution in TW Hya's disk

    CERN Document Server

    Hogerheijde, Michiel R; Pinilla, Paola; Salinas, Vachail N; Kama, Mihkel; Andrews, Sean M; Qi, Chunhua; Wilner, David J

    2015-01-01

    Grain growth in planet-forming disks is the first step toward the formation of planets. The growth of grains and their inward drift leaves a distinct imprint on the dust surface-density distribution and the resulting surface-brightness profile of the thermal continuum emission. We determine the surface-brightness profile of the continuum emission using resolved observations at millimeter wavelengths of the disk around TW Hya, and infer the signature of dust evolution on the surface density and dust opacity. Archival ALMA observations at 820 micron on baselines up to 410 kilolambda are compared to parametrized disk models to determine the surface-brightness profile. Under the assumption of a constant dust opacity, a broken radial power law best describes the dust surface density, with a slope of -0.53 +/- 0.01 from the 4.1 au radius of the (already known) inner hole to a turn-over radius of 47.1 +/- 0.2 au, steepening to -8.0 +/- 0.1 at larger radii. The emission drops below the detection limit beyond ~60 au. ...

  16. Herschel/PACS view of disks around low-mass stars and brown dwarfs in the TW Hya association

    CERN Document Server

    Liu, Yao; Gong, Munan; Allers, Katelyn N; Brown, Joanna M; Kraus, Adam L; Liu, Michael C; Shkolnik, Evgenya L; van Dishoeck, Ewine F

    2014-01-01

    We conducted Herschel/PACS observations of five very low-mass stars or brown dwarfs located in the TW Hya association with the goal of characterizing the properties of disks in the low stellar mass regime. We detected all five targets at $70\\,\\mu{\\rm{m}}$ and $100\\,\\mu{\\rm{m}}$ and three targets at $160\\,\\mu{\\rm{m}}$. Our observations, combined with previous photometry from 2MASS, WISE, and SCUBA-2, enabled us to construct SEDs with extended wavelength coverage. Using sophisticated radiative transfer models, we analyzed the observed SEDs of the five detected objects with a hybrid fitting strategy that combines the model grids and the simulated annealing algorithm and evaluated the constraints on the disk properties via the Bayesian inference method. The modelling suggests that disks around low-mass stars and brown dwarfs are generally flatter than their higher mass counterparts, but the range of disk mass extends to well below the value found in T Tauri stars, and the disk scale heights are comparable in both...

  17. On a role of corotation radius in the low $T/W$ dynamical instability of differentially rotating stars

    CERN Document Server

    Yoshida, Shin'ichirou

    2016-01-01

    We investigate the nature of so-called low $T/W$ dynamical instability in a differentially rotating star by focusing on the role played by the corotation radius of the unstable oscillation modes. An one dimensional model of linear perturbation, which neglects dependence of variables on the coordinate along the rotational axis of the star, is solved to obtain stable and unstable eigenmodes. A linear eigenmode having a corotation radius, at which azimuthal pattern speed of the mode coincides with the stellar angular velocity, is categorized to either a complex (growing or damping) mode or a purely real mode belonging to a continuous spectrum of frequency. We compute canonical angular momentum and its flux to study eigenmodes with corotation radius. In a dynamically unstable mode, sound wave transports its angular momentum in such a way that the absolute value of the angular momentum is increased on both sides of the corotation radius. We further evaluate growth of amplitude of reflected sound wave incident to a...

  18. Measurements of the thermal conductivity of compressed beryllium pebble beds. EDFA reference: TW2-TTBB-007a D4

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, J.; Piazza, G.; Xu, Z. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Kern- und Energietechnik, Programm Kernfusion; Goraieb, A.; Harsch, H. [Goraieb Versuchstechnik, Karlsruhe (Germany)

    2005-05-01

    For helium cooled pebble bed blankets, the description of the thermal-mechanical interaction between pebble beds and structural material requires the knowledge of the pebble bed thermal conductivity k as a function of temperature T and deformation state (pebble bed strain {epsilon}). In the frame of the EFDA Technology Work Programme TW2-TTBB-007a-D4, the measurements of thermal and mechanical parameters of beryllium pebble beds have been performed in the HECOP facility in the Forschungszentrum Karlsruhe. This report gives a summary of previous work on the thermal conductivity k of beryllium pebble beds, describes the experimental set-up, and presents the new experimental results. The investigated pebble beds, consisting of 1 mm pebbles, are representative for dense pebble beds (vibrated after filling, packing factors of {approx}63.5%). Measurements were performed at bed temperatures between 200 and 650 C and maximum pebble bed deformations up to 3.5%. For this parameter range, two different correlations for the thermal conductivity k as a function of pebble bed deformation {epsilon} and temperature T are proposed. The first one is primarily based on measurements but makes use of the conductivity values for non-deformed pebble beds predicted by the Schluender Bauer Zehner (SBZ) model. (orig.)

  19. A Significantly Low CO Abundance Toward the TW Hya Protoplanetary Disk: A Path to Active Carbon Chemistry?

    CERN Document Server

    Favre, Cécile; Bergin, Edwin A; Qi, Chunhua; Blake, Geoffrey A

    2013-01-01

    In this Letter we report the CO abundance relative to H2 derived toward the circumstellar disk of the T-Tauri star TW Hya from the HD (1-0) and C18O (2-1) emission lines. The HD (1-0) line was observed by the Herschel Space Observatory Photodetector Array Camera and Spectrometer whereas C18O (2-1) observations were carried out with the Submillimeter Array at a spatial resolution of 2.8" x 1.9" (corresponding to 142 x 97 AU). In the disk's warm molecular layer (T>20 K) we measure a disk-averaged gas-phase CO abundance relative to H2 of $\\chi{\\rm(CO)}=(0.1-3)x10^{-5}$, substantially lower than the canonical value of $\\chi{\\rm(CO)}=10^{-4}$. We infer that the best explanation of this low $\\chi$(CO) is the chemical destruction of CO followed by rapid formation of carbon chains, or perhaps CO2, that can subsequently freeze-out, resulting in the bulk mass of carbon locked up in ice grain mantles and oxygen in water. As a consequence of this likely time-dependent carbon sink mechanism, CO may be an unreliable tracer...

  20. Development of x-ray and ion diagnostics of plasma obtained with a 10-TW femtosecond laser

    Science.gov (United States)

    Ryć, L.; Dobrzański, L.; Dubecky, F.; Jabłoński, S.; Parys, P.; Słysz, W.; Rosiński, M.

    2016-07-01

    Several x-ray and ion semiconductor detectors have been developed for the diagnostics of femtosecond laser plasma generated by a 10-TW laser which was recently commissioned for operation at the Institute of Plasma Physics and Laser Microfusion, Warsaw. A range of detectors has been employed including a CdTe detector for hard x-rays and four detectors for proton detection. These four are SiC and GaN employing a sandwich structure, an interdigitated M-S-M InP detector and finally a silicon photo-diode equipped with an aluminium filter (to shield against scattered light). The detectors presented are innovative as they are not commonly used for the diagnostic of laser plasma. The details of the internal structures of the detectors are presented. The immunity of the detectors to the noise coming from the laser system and the femtosecond plasma is discussed. Lastly, the possibility for further modifications and improvements are considered and discussed.

  1. HYDRA VULGARIS PALLAS, 1766 (HYDROZOA: HYDRIDAE AS BIOINDICATOR OF THE WATER QUALITY OF THE RIVER CHILI, AREQUIPA, PERU

    Directory of Open Access Journals (Sweden)

    Ronald Huarachi

    2012-12-01

    Full Text Available The aim of this study was to use Hydra vulgaris Pallas, 1766 (Hydrozoa: Hydridae as a bioindicator of water quality of the Chili River, Arequipa, Peru. The freshwater hydra were collected in the spring "Ojo del Milagro", Characato District, Arequipa, Peru. H. vulgaris was cultivated under standardized conditions and were fed Artemia sp. K2Cr2O7 was used as a positive control and as a reference toxin. Acute toxicity and morphological changes of H. vulgaris were evaluated on Tiabaya and Tingo, sampling points of the Chili River. The LC50 (median lethal concentration showed: Tingo (LC50-96h = 135.95% classifying it as non-toxic and Tiabaya (LC50 -24h = 61.83%, classifying it as moderately toxic; LC50-48h = 44.19% and LC50 -72h = 38.28% classifying them as toxic; LC50 -96h = 21.44% rating it as very toxic. Significant differences in the morphological changes of H. vulgaris were observed with regard to different concentrations and exposure time in waters sampled from Tingo from 48 h to 96 h and in Tiabaya, significant differences in morphological changes from 24 h to 96 h exposure. The results of the physicochemical parameters of the Chili River were compared with the Peruvian National Standards for Environmental Quality (ECA for water (categories 3 and 4 and recorded high values of biochemical oxygen demand BOD5, NH4 and PO4, and low dissolved oxigen OD values for Tiabaya. In Tingo, NH4 and phosphate were high. In Tiabaya, water was considered more toxic than at Tingo.

  2. Somatostatin signaling system as an ancestral mechanism: Myoregulatory activity of an Allatostatin-C peptide in Hydra.

    Science.gov (United States)

    Alzugaray, María Eugenia; Hernández-Martínez, Salvador; Ronderos, Jorge Rafael

    2016-08-01

    The coordination of physiological processes requires precise communication between cells. Cellular interactions allow cells to be functionally related, facilitating the maintaining of homeostasis. Neuropeptides functioning as intercellular signals are widely distributed in Metazoa. It is assumed that neuropeptides were the first intercellular transmitters, appearing early during the evolution. In Cnidarians, neuropeptides are mainly involved in neurotransmission, acting directly or indirectly on epithelial muscle cells, and thereby controlling coordinated movements. Allatostatins are a group of chemically unrelated neuropeptides that were originally characterized based on their ability to inhibit juvenil hormone synthesis in insects. Allatostatin-C has pleiotropic functions, acting as myoregulator in several insects. In these studies, we analyzed the myoregulatory effect of Aedes aegypti Allatostatin-C in Hydra sp., a member of the phylum Cnidaria. Allatostatin-C peptide conjugated with Qdots revealed specifically distributed cell populations that respond to the peptide in different regions of hydroids. In vivo physiological assays using Allatostatin-C showed that the peptide induced changes in shape and length in tentacles, peduncle and gastrovascular cavity. The observed changes were dose and time dependent suggesting the physiological nature of the response. Furthermore, at highest doses, Allatostatin-C induced peristaltic movements of the gastrovascular cavity resembling those that occur during feeding. In silico search of putative Allatostatin-C receptors in Cnidaria showed that genomes predict the existence of proteins of the somatostatin/Allatostatin-C receptors family. Altogether, these results suggest that Allatostatin-C has myoregulatory activity in Hydra sp, playing a role in the control of coordinated movements during feeding, indicating that Allatostatin-C/Somatostatin based signaling might be an ancestral mechanism.

  3. The Hydra regeneration assay reveals ecological risks in running waters: a new proposal to detect environmental teratogenic threats.

    Science.gov (United States)

    Traversetti, Lorenzo; Del Grosso, Floriano; Malafoglia, Valentina; Colasanti, Marco; Ceschin, Simona; Larsen, Stefano; Scalici, Massimiliano

    2017-03-01

    The regenerative ability of Hydra vulgaris was tested as potential biomarker for the development of a new eco-toxicological index. The test is based on the regeneration rate and the aberration frequency of the columna (body and adhesive foot) after separation from head and tentacles by a bistoury. Particularly, 45 columnae were submerged in the rearing solution (that is Hydra medium) to have control, and 285 in potential contaminated waters to have treatments, collected from 19 sites along 10 rivers in central Italy. ANCOVA and chi-square tests were used to compare values from each site to a laboratory control. Subsequently the values on regeneration rate and aberration frequency were inserted in a double entry matrix, where the match of the two entries in the matrix provides the score of the proposed Teratogenic Risk Index (TRI). Each score corresponded to one of the 5 teratogenic risk classes, to which a risk level was associated: from 1 (no risk) to 5 (very high risk). On the whole, 32% of the studied sites were classified as no teratogenic risk while the remaining showed a variable risk level from low to very high. This study proposed for the first time an early warning system to detect the presence of teratogens in running waters, providing a rapid and cost-effective evaluation method. Therefore, TRI may contribute to initiate adequate measures to manage riverine habitats, and to monitor the running water teratogenic status. Specifically, this index may provide the opportunity to identify the disturbance sources and then to drive the decisions, together with competent authorities, on the catchment and landscape management and on the possible use of waters for urban, agricultural, and industrial activities, since they may show significant effects on the human health.

  4. Timescales of Disk Evolution and Planet Formation

    CERN Document Server

    Jayawarhana, R

    2000-01-01

    It has been suggested that circumstellar disks evolve from dense, actively accreting structures to low-mass, replenished remnants. During this transition, grains may assemble into planetesimals, or the disk may be cleared by newborn planets. Recently identified nearby groups of young stars provide valuable laboratories for probing disk evolution. I discuss the properties of dust disks in the TW Hydrae Association and the MBM 12 cloud, and compare the results to other studies of disk evolution and planet formation timescales.

  5. Fracture mechanical experiments on EUROFER 97 and MANET II mini-bar specimens. Final report for task TW5-TTMS 005-D04

    Energy Technology Data Exchange (ETDEWEB)

    Gaganidze, E.; Dafferner, B.; Aktaa, J.

    2006-08-15

    This report summarizes Fracture Mechanical (FM) experiments carried out under the contract of the European Fusion Development Agreement (EFDA), subtask TW5-TTMS-005-D04 for supporting the modeling work on size effects in ductile and ductile to brittle transition region performed within a task TW5-TTMS-005-D3. Quasi-static three-point-bend (3PB) experiments have been performed on the European reference RAFM steel EUROFER 97 and on a martensitic steel MANET II. The crack resistance curves have been constructed from the original fracture mechanical data in the ductile and ductile to brittle transition regions. Additionally, in the ductile region, where complexity of the three dimensional fracture surfaces prevented an explicit quantitative assessment of the crack extension, the validity of the failure assessment diagram (R6) has been verified for RAFM steel EUROFER 97. (orig.) [German] In diesem Bericht werden die bruchmechanischen Untersuchungen zusammengefasst, welche zur Unterstuetzung von Modellierungsarbeiten von Groesseneffekten in duktilen und sproedduktilen Uebergangsbereichen (Subtask TW5-TTMS-005-D03) im Rahmen des Europaeischen Abkommens zur Entwicklung der Fusionsforschung (EFDA), Subtask TW5-TTMS-005-D04 durchgefuehrt wurden. Es wurden quasi-statische Drei-Punkt-Biegeversuche (3PB) an dem Europaeischen RAFM Referenzstahl EUROFER 97 und an dem martensitischen Stahl MANET II durchgefuehrt. Die Risswiderstandskurven wurden durch die Auswertung von bruchmechanischen Versuchen in duktilen und sproed-duktilen Uebergangsbereichen erstellt. Im duktilen Bereich, wo die Komplexitaet der drei dimensionalen Bruchflaechen eine explizite quantitative Auswertung des Risswachstums verhinderte, wurde zusaetzlich die Gueltigkeit der Auslegungskurve (R6) an dem RAFM Stahl EUROFER 97 ueberprueft.

  6. Tetrandrine Induces Apoptosis of Human Nasopharyngeal Carcinoma NPC-TW 076 Cells through Reactive Oxygen Species Accompanied by an Endoplasmic Reticulum Stress Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Ya-Jing Lin

    2016-10-01

    Full Text Available Nasopharyngeal carcinoma (NPC is an epithelial malignancy of the head and neck and the incidence is higher in Southeast Asia. Tetrandrine (TET is a bisbenzylisoquinoline alkaloid, a natural product, and exhibits biological activities including action against many human cancer cell lines. However, the molecular mechanism of TET-induced cell apoptosis in human NPC cells is still unclear. In the present study, we investigated TET-induced apoptotic cell death and associated possible signal pathways on human nasopharyngeal carcinoma NPC-TW 076 cells in vitro. Phase contrast microscopy was used to examine cell morphology and DAPI staining was used to examine chromatin condensation. Flow cytometry assay was used to measure total viable cells, cell cycle and sub-G1 phase distribution, reactive oxygen species (ROS, Ca2+, and mitochondria membrane potential (ΔΨm in NPC-TW 076 cells. Results indicate that TET induced cell death through the cell morphological changes, caused G0/G1 phase arrest, increased ROS and Ca2+ production, and finally caused apoptotic cell death in NPC-TW 076 cells. There was no influence on the level of ΔΨm after TET treatment. Western blotting indicated that TET increased endoplasmic reticulum (ER stress associated protein expression such as GADD153, GRP78, ATF-6α and ATF-6 βwhich indicated that TET induced cell death through ER stress. ER stress is a potential target in cancer treatment, so the ability of TET to induce ER stress response and to activate programming cell death in NPC-TW 076 cells make this molecule become a promising anticancer agent.

  7. Tetrandrine Induces Apoptosis of Human Nasopharyngeal Carcinoma NPC-TW 076 Cells through Reactive Oxygen Species Accompanied by an Endoplasmic Reticulum Stress Signaling Pathway.

    Science.gov (United States)

    Lin, Ya-Jing; Peng, Shu-Fen; Lin, Meng-Liang; Kuo, Chao-Lin; Lu, Kung-Wen; Liao, Ching-Lung; Ma, Yi-Shih; Chueh, Fu-Shin; Liu, Kuo-Ching; Yu, Fu-Shun; Chung, Jing-Gung

    2016-10-12

    Nasopharyngeal carcinoma (NPC) is an epithelial malignancy of the head and neck and the incidence is higher in Southeast Asia. Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid, a natural product, and exhibits biological activities including action against many human cancer cell lines. However, the molecular mechanism of TET-induced cell apoptosis in human NPC cells is still unclear. In the present study, we investigated TET-induced apoptotic cell death and associated possible signal pathways on human nasopharyngeal carcinoma NPC-TW 076 cells in vitro. Phase contrast microscopy was used to examine cell morphology and DAPI staining was used to examine chromatin condensation. Flow cytometry assay was used to measure total viable cells, cell cycle and sub-G₁ phase distribution, reactive oxygen species (ROS), Ca(2+), and mitochondria membrane potential (ΔΨm) in NPC-TW 076 cells. Results indicate that TET induced cell death through the cell morphological changes, caused G₀/G₁ phase arrest, increased ROS and Ca(2+) production, and finally caused apoptotic cell death in NPC-TW 076 cells. There was no influence on the level of ΔΨm after TET treatment. Western blotting indicated that TET increased endoplasmic reticulum (ER) stress associated protein expression such as GADD153, GRP78, ATF-6α and ATF-6 βwhich indicated that TET induced cell death through ER stress. ER stress is a potential target in cancer treatment, so the ability of TET to induce ER stress response and to activate programming cell death in NPC-TW 076 cells make this molecule become a promising anticancer agent.

  8. A Fast and Efficient Version of the TwO-Moment Aerosol Sectional (TOMAS) Global Aerosol Microphysics Model

    Science.gov (United States)

    Lee, Yunha; Adams, P. J.

    2012-01-01

    This study develops more computationally efficient versions of the TwO-Moment Aerosol Sectional (TOMAS) microphysics algorithms, collectively called Fast TOMAS. Several methods for speeding up the algorithm were attempted, but only reducing the number of size sections was adopted. Fast TOMAS models, coupled to the GISS GCM II-prime, require a new coagulation algorithm with less restrictive size resolution assumptions but only minor changes in other processes. Fast TOMAS models have been evaluated in a box model against analytical solutions of coagulation and condensation and in a 3-D model against the original TOMAS (TOMAS-30) model. Condensation and coagulation in the Fast TOMAS models agree well with the analytical solution but show slightly more bias than the TOMAS-30 box model. In the 3-D model, errors resulting from decreased size resolution in each process (i.e., emissions, cloud processing wet deposition, microphysics) are quantified in a series of model sensitivity simulations. Errors resulting from lower size resolution in condensation and coagulation, defined as the microphysics error, affect number and mass concentrations by only a few percent. The microphysics error in CN70CN100 (number concentrations of particles larger than 70100 nm diameter), proxies for cloud condensation nuclei, range from 5 to 5 in most regions. The largest errors are associated with decreasing the size resolution in the cloud processing wet deposition calculations, defined as cloud-processing error, and range from 20 to 15 in most regions for CN70CN100 concentrations. Overall, the Fast TOMAS models increase the computational speed by 2 to 3 times with only small numerical errors stemming from condensation and coagulation calculations when compared to TOMAS-30. The faster versions of the TOMAS model allow for the longer, multi-year simulations required to assess aerosol effects on cloud lifetime and precipitation.

  9. Arabic summarization in Tw

    Directory of Open Access Journals (Sweden)

    Nawal El-Fishawy

    2014-06-01

    Full Text Available Twitter, an online micro blogs, enables its users to write and read text-based posts known as “tweets”. It became one of the most commonly used social networks. However, an important problem arises is that the returned tweets, when searching for a topic phrase, are only sorted by recency not relevancy. This makes the user to manually read through the tweets in order to understand what are primarily saying about the particular topic. Some strategies were developed for summarizing English micro blogs but Arabic micro blogs summarization is still an active research area. This paper presents a machine learning based solution for summarizing Arabic micro blogging posts and more specifically Egyptian dialect summarization. The goal is to produce short summary for Arabic tweets related to a specific topic in less time and effort. The proposed strategy is evaluated and the results are compared with that obtained by the well-known multi-document summarization algorithms including; SumBasic, TF-IDF, PageRank, MEAD, and human summaries.

  10. HYDRA-I: a three-dimensional finite difference code for calculating the thermohydraulic performance of a fuel assembly contained within a canister

    Energy Technology Data Exchange (ETDEWEB)

    McCann, R.A.

    1980-12-01

    A finite difference computer code, named HYDRA-I, has been developed to simulate the three-dimensional performance of a spent fuel assembly contained within a cylindrical canister. The code accounts for the coupled heat transfer modes of conduction, convection, and radiation and permits spatially varying boundary conditions, thermophysical properties, and power generation rates. This document is intended as a manual for potential users of HYDRA-I. A brief discussion of the governing equations, the solution technique, and a detailed description of how to set up and execute a problem are presented. HYDRA-I is designed for operation on a CDC 7600 computer. An appendix is included that summarizes approximately two dozen different cases that have been examined. The cases encompass variations in fuel assembly and canister configurations, power generation rates, filler materials, and gases. The results presented show maximum and various local temperatures and heat fluxes illustrating the changing importance of the three heat transfer modes. Finally, the need for comparison with experimental data is emphasized as an aid in code verification although the limited data available indicate excellent agreement.

  11. Multi-scale biomarker evaluation of the toxicity of a commercial azo dye (Disperse Red 1) in an animal model, the freshwater cnidarian Hydra attenuata.

    Science.gov (United States)

    de Jong, Laetitia; Pech, Nicolas; de Aragão Umbuzeiro, Gisela; Moreau, Xavier

    2016-06-01

    Acute (24 h, 48 h, 72 h) and chronic (7 days) tests have been performed to evaluate the effects of the commercial azo dye Disperse Red 1 (DR1) using various biomarkers in the freshwater invertebrate Hydra attenuata. Morphological changes have been selected to calculate ecotoxicological thresholds for sublethal and lethal DR1 concentrations. A multinomial logistic model showed that the probability of each morphological stage occurrence was function of concentration, time and interaction between both. Results of oxidative balance parameter measurements (72 h and 7 days) suggest that polyps set up defense mechanisms to limit lipid peroxidation caused by DR1. DR1 exposure at hormetic concentrations induces increase of asexual reproductive rates. This result suggests (1) an impact on the fitness-related phenotypical traits and (2) trade-offs between reproduction and maintenance to allow the population to survive harsher conditions. Changes in serotonin immuno-labeling in polyps showing alterations in feeding behavior suggest that chronic DR1 exposure impaired neuronal processes related to ingesting behavior in H. attenuata. This ecotoxicity study sheds light on the possible serotonin function in Hydra model and reports for the first time that serotonin could play a significant role in feeding behavior. This study used a multi-scale biomarker approach investigating biochemical, morphological, reproductive and behavioral endpoints in Hydra attenuata. This organism is proposed for a pertinent animal model to assess ecotoxicological impact of pollutant mixtures in freshwater environment.

  12. Ecotoxicological assessment of cobalt using Hydra model: ROS, oxidative stress, DNA damage, cell cycle arrest, and apoptosis as mechanisms of toxicity.

    Science.gov (United States)

    Zeeshan, Mohammed; Murugadas, Anbazhagan; Ghaskadbi, Surendra; Ramaswamy, Babu Rajendran; Akbarsha, Mohammad Abdulkader

    2017-05-01

    The mechanisms underlying cobalt toxicity in aquatic species in general and cnidarians in particular remain poorly understood. Herein we investigated cobalt toxicity in a Hydra model from morphological, histological, developmental, and molecular biological perspectives. Hydra, exposed to cobalt (0-60 mg/L), were altered in morphology, histology, and regeneration. Exposure to standardized sublethal doses of cobalt impaired feeding by affecting nematocytes, which in turn affected reproduction. At the cellular level, excessive ROS generation, as the principal mechanism of action, primarily occurred in the lysosomes, which was accompanied by the upregulation of expression of the antioxidant genes SOD, GST, GPx, and G6PD. The number of Hsp70 and FoxO transcripts also increased. Interestingly, the upregulations were higher in the 24-h than in the 48-h time-point group, indicating that ROS overwhelmed the cellular defense mechanisms at the latter time-point. Comet assay revealed DNA damage. Cell cycle analysis indicated the induction of apoptosis accompanied or not by cell cycle arrest. Immunoblot analyses revealed that cobalt treatment triggered mitochondria-mediated apoptosis as inferred from the modulation of the key proteins Bax, Bcl-2, and caspase-3. From this data, we suggest the use of Hydra as a model organism for the risk assessment of heavy metal pollution in aquatic ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Laser Driven Compression Equations of State and Hugoniot Pressure Measurements in Thick Solid Metallic Targets at ˜0.17-13 TW/cm2

    Science.gov (United States)

    Remo, John L.

    2010-10-01

    An electro-optic laser probe was developed to obtain parameters for high energy density equations of state (EoS), Hugoniot pressures (PH), and strain rates for high energy density laser irradiation intensity, I, experiments at ˜170 GW/cm2 (λ = 1064 nm) to ˜13 TW/cm2 (λ = 527 nm) on Al, Cu, Ti, Fe, Ni metal targets in a vacuum. At I ˜7 TW/cm2 front surface plasma pressures and temperatures reached 100's GPa and over two million K. Rear surface PH ranged from 7-120 GPa at average shock wave transit velocities 4.2-8.5 km/s, depending on target thickness and I. A surface plasma compression ˜100's GPa generated an impulsive radial expanding shock wave causing compression, rarefactions, and surface elastic and plastic deformations depending on I. A laser/fiber optic system measured rear surface shock wave emergence and particle velocity with ˜3 GHz resolution by monitoring light deflection from diamond polished rear surfaces of malleable metallic targets, analogous to an atomic force microscope. Target thickness, ˜0.5-2.9 mm, prevented front surface laser irradiation penetration, due to low radiation skin depth, from altering rear surface reflectivity (refractive index). At ˜10 TW electromagnetic plasma pulse noise generated from the target chamber overwhelmed detector signals. Pulse frequency analysis using Moebius loop antennae probed transient noise characteristics. Average shock (compression) and particle (rear surface displacement) velocity measurements determined rear surface PH and GPa) EoS that are compared with gas guns.

  14. Healthhazard evaluation report HETA 84-075-1634, Hydra-Matic Division of General Motors, Ypsilanti, Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, W.J.; Orris, P.

    1985-11-01

    Environmental and breathing-zone samples were analyzed for total particulates, trace metals, glycol ethers, and other organic materials at Hydra/Matic, a division of General Motors, in Ypsilanti, Michigan in March, 1984 and March, 1985. The evaluation was requested confidentially to investigate employee exposures to machine coolants and additives used in the centerless grinding operation. The central coolant system had been contaminated by sewage and high concentrations of chemicals had reportedly been added to the system to prevent bacterial growth. Questionnaire interviews were conducted with 75 employees. Eye irritation, sinus congestion, rhinitis, daily cough, upper respiratory infections, and skin complaints such as frequent dryness, itching, rash, and pimples were reported. All concentrations of chemical agents were below their relevant standards or not detectable. The authors note that no airborne contaminant that would pose a health hazard has been identified. Recommendations include properly maintaining the coolant system and individual machines, training employees in proper work practices for use with cutting fluids, and making barrier creams and protective clothing available.

  15. Constraints on the gamma-ray emission from the cluster-scale AGN outburst in the Hydra A galaxy cluster

    CERN Document Server

    Abramowski, A; Aharonian, F; Akhperjanian, A G; Anton, G; Balenderan, S; Balzer, A; Barnacka, A; Becherini, Y; Becker, J; Bernloehr, K; Birsin, E; Biteau, J; Bochow, A; Boisson, C; Bolmont, J; Bordas, P; Brucker, J; Brun, F; Brun, P; Bulik, T; Buesching, I; Carrigan, S; Casanova, S; Cerruti, M; Chadwick, P M; Charbonnier, A; Chaves, R C G; Cheesebrough, A; Cologna, G; Conrad, J; Couturier, C; Daniel, M K; Davids, I D; Degrange, B; Deil, C; Dickinson, H J; Djannati-Atai, A; Domainko, W; Drury, L O'C; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Egberts, K; Eger, P; Espigat, P; Fallon, L; Fegan, S; Feinstein, F; Fernandes, M V; Fiasson, A; Fontaine, G; Foerster, A; Fuessling, M; Gajdus, M; Gallant, Y A; Garrigoux, T; Gast, H; Gerard, L; Giebels, B; Glicenstein, J F; Glueck, B; Goering, D; Grondin, M -H; Haeffner, S; Hague, J D; Hahn, J; Hampf, D; Harris, J; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hillert, A; Hinton, J A; Hofmann, W; Hofverberg, P; Holler, M; Horns, D; Jacholkowska, A; Jahn, C; Jamrozy, M; Jung, I; Kastendieck, M A; Katarzynski, K; Katz, U; Kaufmann, S; Khelifi, B; Klochkov, D; Kluzniak, W; Kneiske, T; Komin, Nu; Kosack, K; Kossakowski, R; Krayzel, F; Laffon, H; Lamanna, G; Lenain, J -P; Lennarz, D; Lohse, T; Lopatin, A; Lu, C -C; Marandon, V; Marcowith, A; Masbou, J; Maurin, G; Maxted, N; Mayer, M; McComb, T J L; Medina, M C; Mehault, J; Moderski, R; Mohamed, M; Moulin, E; Naumann, C L; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Nguyen, N; Nicholas, B; Niemiec, J; Nolan, S J; Ohm, S; Wilhelmi, E de Ona; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Arribas, M Paz; Pekeur, N W; Pelletier, G; Perez, J; Petrucci, P -O; Peyaud, B; Pita, S; Puehlhofer, G; Punch, M; Quirrenbach, A; Raue, M; Reimer, A; Reimer, O; Renaud, M; Reyes, R de los; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Sahakian, V; Sanchez, D A; Santangelo, A; Schlickeiser, R; Schulz, A; Schwanke, U; Schwarzburg, S; Schwemmer, S; Sheidaei, F; Skilton, J L; Sol, H; Spengler, G; Stawarz, L; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Szostek, A; Tavernet, J -P; Terrier, R; Tluczykont, M; Valerius, K; van Eldik, C; Vasileiadis, G; Venter, C; Viana, A; Vincent, P; Voelk, H J; Volpe, F; Vorobiov, S; Vorster, M; Wagner, S J; Ward, M; White, R; Wierzcholska, A; Zacharias, M; Zajczyk, A; Zdziarski, A A; Zech, A; Zechlin, H -S; Ali, M O

    2012-01-01

    In some galaxy clusters powerful AGN have blown bubbles with cluster scale extent into the ambient medium. The main pressure support of these bubbles is not known to date, but cosmic rays are a viable possibility. For such a scenario copious gamma-ray emission is expected as a tracer of cosmic rays from these systems. Hydra A, the closest galaxy cluster hosting a cluster scale AGN outburst, located at a redshift of 0.0538, is investigated for being a gamma-ray emitter with the High Energy Stereoscopic System (H.E.S.S.) array and the Fermi Large Area Telescope (Fermi-LAT). Data obtained in 20.2 hours of dedicated H.E.S.S. observations and 38 months of Fermi-LAT data, gathered by its usual all-sky scanning mode, have been analyzed to search for a gamma-ray signal. No signal has been found in either data set. Upper limits on the gamma-ray flux are derived and are compared to models. These are the first limits on gamma-ray emission ever presented for galaxy clusters hosting cluster scale AGN outbursts. The non-de...

  16. A Radiation-Hydrodynamics Code Comparison for Laser-Produced Plasmas: FLASH versus HYDRA and the Results of Validation Experiments

    CERN Document Server

    Orban, Chris; Chawla, Sugreev; Wilks, Scott C; Lamb, Donald Q

    2013-01-01

    The potential for laser-produced plasmas to yield fundamental insights into high energy density physics (HEDP) and deliver other useful applications can sometimes be frustrated by uncertainties in modeling the properties and expansion of these plasmas using radiation-hydrodynamics codes. In an effort to overcome this and to corroborate the accuracy of the HEDP capabilities recently added to the publicly available FLASH radiation-hydrodynamics code, we present detailed comparisons of FLASH results to new and previously published results from the HYDRA code used extensively at Lawrence Livermore National Laboratory. We focus on two very different problems of interest: (1) an Aluminum slab irradiated by 15.3 and 76.7 mJ of "pre-pulse" laser energy and (2) a mm-long triangular groove cut in an Aluminum target irradiated by a rectangular laser beam. Because this latter problem bears a resemblance to astrophysical jets, Grava et al., Phys. Rev. E, 78, (2008) performed this experiment and compared detailed x-ray int...

  17. Detection of a Degenerate Companion of the SX Phoenicis Star KZ Hydrae by Studying its Long-Term Variability

    Science.gov (United States)

    Fu, J. N.; Khokhuntod, P.; Rodríguez, E.; Boonyarak, C.; Marak, K.; López-González, M. J.; Zhu, L. Y.; Qian, S. B.; Jiang, S. Y.

    2008-05-01

    We present 109 new times of maximum light of the SX Phoenicis (SX Phe) star KZ Hydrae (KZ Hya) based mainly on our extensive photometric observations for two decades, leading to determination of a general ephemeris combined with the data in the literature. The O - C diagram reveals a continuously increasing period change combined with the light traveling time effect of the orbital motion of KZ Hya in a binary system with an orbital period of 26.8 ± 0.2 years. The deduced mass of the companion cannot be smaller than 0.83 M sun. Since no sign of the companion has ever been observed spectroscopically and the observed color index b - y excludes the possibility of the companion being a late-type main-sequence or dwarf star, KZ Hya becomes the first SX Phe star for which a degenerate companion is detected. The pulsation properties are studied by analyzing the Fourier spectra of the observed light curves while the fundamental parameters are deduced with the simultaneous multicolor uvbyβ data, showing this star to be a strong low-metallicity high-amplitude SX Phe-type variable pulsating in the fundamental radial mode. No signs of multiperiodicity or significant long-term changes in amplitude are detected in the pulsation of this variable.

  18. The mitochondrial genome of Hydra oligactis (Cnidaria, Hydrozoa) sheds new light on animal mtDNA evolution and cnidarian phylogeny.

    Science.gov (United States)

    Kayal, Ehsan; Lavrov, Dennis V

    2008-02-29

    The 16,314-nuceotide sequence of the linear mitochondrial DNA (mtDNA) molecule of Hydra oligactis (Cnidaria, Hydrozoa)--the first from the class Hydrozoa--has been determined. This sequence contains genes for 13 energy pathway proteins, small and large subunit rRNAs, and methionine and tryptophan tRNAs, as is typical for cnidarians. All genes have the same transcriptional orientation and their arrangement in the genome is similar to that of the jellyfish Aurelia aurita. In addition, a partial copy of cox1 is present at one end of the molecule in a transcriptional orientation opposite to the rest of the genes, forming a part of inverted terminal repeat characteristic of linear mtDNA and linear mitochondrial plasmids. The sequence close to at least one end of the molecule contains several homonucleotide runs as well as small inverted repeats that are able to form strong secondary structures and may be involved in mtDNA maintenance and expression. Phylogenetic analysis of mitochondrial genes of H. oligactis and other cnidarians supports the Medusozoa hypothesis but also suggests that Anthozoa may be paraphyletic, with octocorallians more closely related to the Medusozoa than to the Hexacorallia. The latter inference implies that Anthozoa is paraphyletic and that the polyp (rather than a medusa) is the ancestral body type in Cnidaria.

  19. WIYN Open Cluster Study. XXXIX. Abundances in NGC 6253 from HYDRA Spectroscopy of the Li 6708 A Region

    CERN Document Server

    Anthony-Twarog, B J; Twarog, B A; Cummings, J D; Maderak, R M

    2010-01-01

    High-dispersion spectra of 89 potential members of the old, super-metal-rich open cluster, NGC 6253, have been obtained with the HYDRA multi-object spectrograph. Based upon radial-velocity measurements alone, 47 stars at the turnoff of the cluster color-magnitude diagram (CMD) and 18 giants are identified as potential members. Five turnoff stars exhibit evidence of binarity while proper-motion data eliminates two of the dwarfs as members. The mean cluster radial velocity from probable single-star members is -29.4 +/- 1.3 km/sec (sd). A discussion of the current estimates for the cluster reddening, derived independently of potential issues with the BV cluster photometry, lead to an adopted reddening of E(B-V) = 0.22 +/- 0.04. From equivalent width analyses of 38 probable single-star members near the CMD turnoff, the weighted average abundances are found to be [Fe/H] = +0.43 +/- 0.01, [Ni/H] = +0.53 +/- 0.02 and [Si/H] = +0.43 (+0.03,-0.04), where the errors refer to the standard errors of the weighted mean. We...

  20. Expulsion of symbiotic algae during feeding by the green hydra--a mechanism for regulating symbiont density?

    Directory of Open Access Journals (Sweden)

    Yelena Fishman

    Full Text Available BACKGROUND: Algal-cnidarian symbiosis is one of the main factors contributing to the success of cnidarians, and is crucial for the maintenance of coral reefs. While loss of the symbionts (such as in coral bleaching may cause the death of the cnidarian host, over-proliferation of the algae may also harm the host. Thus, there is a need for the host to regulate the population density of its symbionts. In the green hydra, Chlorohydra viridissima, the density of symbiotic algae may be controlled through host modulation of the algal cell cycle. Alternatively, Chlorohydra may actively expel their endosymbionts, although this phenomenon has only been observed under experimentally contrived stress conditions. PRINCIPAL FINDINGS: We show, using light and electron microscopy, that Chlorohydra actively expel endosymbiotic algal cells during predatory feeding on Artemia. This expulsion occurs as part of the apocrine mode of secretion from the endodermal digestive cells, but may also occur via an independent exocytotic mechanism. SIGNIFICANCE: Our results demonstrate, for the first time, active expulsion of endosymbiotic algae from cnidarians under natural conditions. We suggest this phenomenon may represent a mechanism whereby cnidarians can expel excess symbiotic algae when an alternative form of nutrition is available in the form of prey.

  1. Tracking mechanical and morphological dynamics of regenerating Hydra tissue fragments using a two fingered micro-robotic hand

    Science.gov (United States)

    Veschgini, M.; Gebert, F.; Khangai, N.; Ito, H.; Suzuki, R.; Holstein, T. W.; Mae, Y.; Arai, T.; Tanaka, M.

    2016-03-01

    Regeneration of a tissue fragment of freshwater polyp Hydra is accompanied by significant morphological fluctuations, suggesting the generation of active forces. In this study, we utilized a two fingered micro-robotic hand to gain insights into the mechanics of regenerating tissues. Taking advantage of a high force sensitivity (˜1 nN) of our micro-hand, we non-invasively acquired the bulk elastic modulus of tissues by keeping the strain levels low (ɛ tissue and determined both viscous modulus and elastic modulus simultaneously, following a simple Maxwell model. We further investigated the correlation between the frequency of force fluctuation and that of morphological fluctuation by monitoring one "tweezed" tissue and the other "intact" tissue at the same time. The obtained results clearly indicated that the magnitude and periodicity of the changes in force and shape are directly correlated, confirming that our two fingered micro-hand can precisely quantify the mechanics of soft, dynamic tissue during the regeneration and development in a non-invasive manner.

  2. Intercomparison Study of Time and Frequency Transfer between VLBI and Other Techniques (GPS, ETS8(TCE), TW(DPN) and DMTD)

    CERN Document Server

    Takiguchi, Hiroshi; Kondo, Tetsuro; Ishii, Atsutoshi; Thomas, Hobiger; Ichikawa, Ryuichi; Koyama, Yasuhiro; Takahashi, Yasuhiro; Nakagawa, Fumimaru; Nakamura, Maho; Tabuchi, Ryo; Tsutshiya, Shigeru; Hama, Shinichi; Gotoh, Tadahiro; Fujieda, Miho; Aida, Masanori; Li, Tingyu; Amagai, Jun

    2011-01-01

    We carried out the intercomparison experiments between VLBI and other techniques to show the capability of VLBI time and frequency transfer by using the current geodetic VLBI technique and facilities as the summary of the experiments that we carried out since 2007. The results from the two different types of experiments show that the VLBI is more stable than GPS but is slightly noisier than two new two-way techniques (TW(DPN), ETS8(TCE)), and VLBI can measure the correct time difference as same as ETS8(TCE).

  3. Skeletal age in idiopathic short stature: An analytical study by the TW3 method, Greulich and Pyle method

    Directory of Open Access Journals (Sweden)

    Kim Hak

    2010-01-01

    Full Text Available Background: The skeletal age in short stature and in various other growth abnormalities is well documented. We lack the study pertaining to the analysis of the skeletal age in idiopathic short stature or analyzing the difference in skeletal age delay or advancement between the familial short stature (FSS and non-familial short stature (non-FSS groups, hence this study. Present retrospective study is designed to study the variation in patterns of skeletal age in ISS. Materials and Methods: One hundred and eighty six patients, 95 males and 91 females of idiopathic short stature were examined to assess the skeletal age deviation in relation to chronological age. The radiographs of the left hand and wrist were done. The skeletal age was assessed using Tanner and Whitehouse (TW3 method and Greulich and Pyle (GP atlas. The patients were divided into two groups based on the parental heights. Group A (Familial Short Stature; FSS with 100 patients (55 males, 45 females included patients whose at least one parent was short and Group B (non-Familial Short Stature; non-FSS with 86 patients (40 males, 46 females, included patients whose parental height was normal. The carpal scores, RUS (Radius, Ulna and Short bone scores and GP age were determined and the respective delay or advances were calculated. Results: The skeletal age in Group A was delayed relative to chronological age by a mean of 1.9 years in males and 2.3 years in females (P< 0.05 by RUS method, mean of 2.7 years in males and 2.6 years in females by Carpal score (P< 0.05, 2.2 years in males and 2.7 years in females by GP atlas age (P< 0.05. The skeletal age in Group B was advanced by a mean of 0.9 years in males and 1.4 years in females (P< 0.05 by RUS method, mean of 0.4 years in males and 0.35 years in females by Carpal score (P< 0.05, mean of 1.1 years in males and 0.2 years in females by GP atlas method (P< 0.05. The Pearson′s coefficient of correlation (P< .001 demonstrated good agreement

  4. The molecular cell death machinery in the simple cnidarian Hydra includes an expanded caspase family and pro- and anti-apoptotic Bcl-2 proteins.

    Science.gov (United States)

    Lasi, Margherita; Pauly, Barbara; Schmidt, Nikola; Cikala, Mihai; Stiening, Beate; Käsbauer, Tina; Zenner, Gerhardt; Popp, Tanja; Wagner, Anita; Knapp, Regina T; Huber, Andreas H; Grunert, Michaela; Söding, Johannes; David, Charles N; Böttger, Angelika

    2010-07-01

    The fresh water polyp Hydra belongs to the phylum Cnidaria, which diverged from the metazoan lineage before the appearance of bilaterians. In order to understand the evolution of apoptosis in metazoans, we have begun to elucidate the molecular cell death machinery in this model organism. Based on ESTs and the whole Hydra genome assembly, we have identified 15 caspases. We show that one is activated during apoptosis, four have characteristics of initiator caspases with N-terminal DED, CARD or DD domain and two undergo autoprocessing in vitro. In addition, we describe seven Bcl-2-like and two Bak-like proteins. For most of the Bcl-2 family proteins, we have observed mitochondrial localization. When expressed in mammalian cells, HyBak-like 1 and 2 strongly induced apoptosis. Six of the Bcl-2 family members inhibited apoptosis induced by camptothecin in mammalian cells with HyBcl-2-like 4 showing an especially strong protective effect. This protein also interacted with HyBak-like 1 in a yeast two-hybrid assay. Mutation of the conserved leucine in its BH3 domain abolished both the interaction with HyBak-like 1 and the anti-apoptotic effect. Moreover, we describe novel Hydra BH-3-only proteins. One of these interacted with Bcl-2-like 4 and induced apoptosis in mammalian cells. Our data indicate that the evolution of a complex network for cell death regulation arose at the earliest and simplest level of multicellular organization, where it exhibited a substantially higher level of complexity than in the protostome model organisms Caenorhabditis and Drosophila.

  5. Hydra myc2, a unique pre-bilaterian member of the myc gene family, is activated in cell proliferation and gametogenesis

    Directory of Open Access Journals (Sweden)

    Markus Hartl

    2014-04-01

    Full Text Available The myc protooncogene encodes the Myc transcription factor which is the essential part of the Myc–Max network controlling fundamental cellular processes. Deregulation of myc leads to tumorigenesis and is a hallmark of many human cancers. We have recently identified homologs of myc (myc1, myc2 and max in the early diploblastic cnidarian Hydra and have characterized myc1 in detail. Here we show that myc2 is transcriptionally activated in the interstitial stem cell system. Furthermore, in contrast to myc1, myc2 expression is also detectable in proliferating epithelial stem cells throughout the gastric region. myc2 but not myc1 is activated in cycling precursor cells during early oogenesis and spermatogenesis, suggesting that the Hydra Myc2 protein has a possible non-redundant function in cell cycle progression. The Myc2 protein displays the principal design and properties of vertebrate Myc proteins. In complex with Max, Myc2 binds to DNA with similar affinity as Myc1–Max heterodimers. Immunoprecipitation of Hydra chromatin revealed that both Myc1 and Myc2 bind to the enhancer region of CAD, a classical Myc target gene in mammals. Luciferase reporter gene assays showed that Myc1 but not Myc2 transcriptionally activates the CAD promoter. Myc2 has oncogenic potential when tested in primary avian fibroblasts but to a lower degree as compared to Myc1. The identification of an additional myc gene in Cnidaria, a phylum that diverged prior to bilaterians, with characteristic expression patterns in tissue homeostasis and developmental processes suggests that principle functions of myc genes have arisen very early in metazoan evolution.

  6. Towards A Complete Census of the Solar-Type Binaries in the Young Open Cluster M37

    Science.gov (United States)

    Geller, Aaron M.; Meibom, Soren; Barnes, Sydney A.; Mathieu, Robert D.

    2012-08-01

    Binary stars govern the dynamical evolution of star clusters and determine the formation rates and mechanisms for exotic stars like blue stragglers and X-ray sources. Understanding the near-primordial (after removal of the natal gas) binary population of star clusters is of primary importance for dynamical models of star clusters, which have the potential to revolutionize our understanding of star cluster evolution. Yet the binary frequencies and distributions of binary orbital parameters (period, eccentricity, etc.) for young coeval stellar populations are poorly known, due to a lack of necessary observations. Time-series radial-velocity surveys are essential for identifying and characterizing binary populations. Using WIYN/Hydra data, we have already identified a nearly complete sample of 329 solar-type (1.5 open cluster M37. Of these stars, 82 show significant radial-velocity variability, indicative of a binary companion. Kinematic orbital solutions are crucial to define the initial binary conditions critical for dynamical star cluster models, and to understand how binaries affects stellar rotational evolution. As we have already identified the binaries in M37, we have a unique opportunity to add significantly to our knowledge of young binaries with minimal additional telescope time. We propose to initiate a WIYN/Hydra multi-epoch radial-velocity survey of the 82 velocity variables in M37.

  7. The Young Visual Binary Database

    Science.gov (United States)

    Prato, Lisa A.; Avilez, Ian; Allen, Thomas; Zoonematkermani, Saeid; Biddle, Lauren; Muzzio, Ryan; Wittal, Matthew; Schaefer, Gail; Simon, Michal

    2017-01-01

    We have obtained adaptive optics imaging and high-resolution H-band and in some cases K-band spectra of each component in close to 100 young multiple systems in the nearby star forming regions of Taurus, Ophiuchus, TW Hya, and Orion. The binary separations for the pairs in our sample range from 30 mas to 3 arcseconds. The imaging and most of our spectra were obtained with instruments behind adaptive optics systems in order to resolve even the closest companions. We are in the process of determining fundamental stellar and circumstellar properties, such as effective temperature, Vsin(i), veiling, and radial velocity, for each component in the entire sample. The beta version of our database includes systems in the Taurus region and provides plots, downloadable ascii spectra, and values of the stellar and circumstellar properties for both stars in each system. This resource is openly available to the community at http://jumar.lowell.edu/BinaryStars/. In this poster we describe initial results from our analysis of the survey data. Support for this research was provided in part by NSF award AST-1313399 and by NASA Keck KPDA funding.

  8. Extragalactic large-scale structures behind the southern Milky Way; 1, redshifts obtained at the SAAO in the Hydra/Antlia extension

    CERN Document Server

    Kraan-Korteweg, R C; Balkowski, C; Kraan-Korteweg, Renee C; Fairall, Tony P; Balkowksi, Chantal

    1994-01-01

    Spectroscopic observations have been carried out for galaxies in the Milky Way with the 1.9 m telescope of the South African Astronomical Observatory (SAAO). The galaxies were selected from a deep optical galaxy search covering 266Hydra and Antlia clusters and in the approximate direction of the dipole anisotropy in the Cosmic Microwave Back- ground radiation. The galaxies in the SAAO observing program -- one of the three complementary approaches in mapping the 3D galaxy distribution in the ZOA -- were selected for high central SB and for even distribution over the search area. The galaxies have magnitudes in the range 14.5Hydra/Antlia supercluster across the ZOA...

  9. Comparison of Strong Gravitational Lens Model Software II. HydraLens: Computer-Assisted Strong Gravitational Lens Model Generation and Translation

    CERN Document Server

    Lefor, Alsn T

    2015-01-01

    The behavior of strong gravitational lens model software in the analysis of lens models is not necessarily consistent among the various software available, suggesting that the use of several models may enhance the understanding of the system being studied. Among the publicly available codes, the model input files are heterogeneous, making the creation of multiple models tedious. An enhanced method of creating model files and a method to easily create multiple models, may increase the number of comparison studies. HydraLens simplifies the creation of model files for four strong gravitational lens model software packages, including Lenstool, Gravlens/Lensmodel, glafic and PixeLens, using a custom designed GUI for each of the four codes that simplifies the entry of the model for each of these codes, obviating the need for user manuals to set the values of the many flags and in each data field. HydraLens is designed in a modular fashion, which simplifies the addition of other strong gravitational lens codes in th...

  10. The Primary Observation of Monster Hydras from Heterograft%异种嫁接的水螅畸形体初步观察

    Institute of Scientific and Technical Information of China (English)

    吴小婷; 吴佩玲; 汪安泰; 吴程琛; 邓利

    2011-01-01

    Hydra robusta and H. Vulgaris were cut transversely in the sub-hypostome region and the basal portion of two hydranth were grafted together. Three kinds of monster hydras, totally 78 individuals were found after 280 days continuous observation, it was shown that: ① monster and its asexual reproduction offspring contained 2 kinds of falcate nematocyst ( H. Robusta' s and H. Vulgaris' falcate nematocyst) ; ② its length could reach 52 mm when it stretched its body; ③ the average period of asexual gemmation was more than 10 days; ④ individuals died after reproducing 3-8 generations; ⑤ those who had 4, 5 and 6 tentacles consisted of 80% , 10% and 10% the individuals respectively; ⑥ it had no sexual reproduction; ⑦ it needed a relatively long time to regenerate after being cut off. When completing regeneration, both its form and development were as the normal one; ⑧ hyperplastic tissue appeared on the surface of its ectoderm, and went to apoptosis on the scapus, or disintegrated 1-2 days after disengaging form matrix; endodenn's cellular conglomeration frequently disengaged from the body, entering digestive chambers. The phenomena of hyperplasia and apoptosis appeared on the monster hydra from heterograft showed that hydra might have primitive immune system that can identify and exclude heterogenetic tissues.%摘要:把强壮水螅(Hydra robusta)和普通水螅(H.vulgaris)除头后进行异种切口嫁接实验,共获得3例畸形体,对其进行280 d的培养,获得78只畸形子代。追踪观察发现:①畸形体及其无性生殖子代均具有2种钩刺丝囊(强壮水媳钩刺丝囊和普通水螅钩刺丝囊);②其身体伸展时最长达52 mm;③无性出芽生殖的平均生殖周期10 d以上;④个体无性生殖3~8代后凋亡;⑤触手数为4、5和6条的个体分别占80%、10%和10%;⑥不发生有性生殖;⑦切割再生时间长,再生后形态与发育特性同术前个体;⑧

  11. Short-term evolution and coexistence of spots, plages and flare activity on LQ Hydrae

    Science.gov (United States)

    Flores Soriano, M.; Strassmeier, K. G.

    2017-01-01

    Aims: We aim to study the short-term evolution of the chromospheric and photospheric activity of the young, single K2 dwarf LQ Hya. Methods: Four months of quasi-simultaneous spectroscopic and photometric observations were used to study the variations of the photometric light curve, the evolution of the chromospheric activity from the Hα and Hβ lines, and the distribution of cool spots from Doppler maps. Results: During our observations one side of the star was more active than the other. The equivalent width of the Hα line from the least active hemisphere increased from ≈0.7 Å at the beginning of the observation to 1.0 Å at the end. The basal emission of the most active hemisphere remained roughly constant at EWHαt1.0 Å. Intense flare activity was observed during the first twenty days, where at least four different events were detected. The line asymmetries of the Hα line suggest that one of the flares could have produced a mass ejection with a maximum projected speed of 70kms-1. The rotational modulation of the V-band photometry showed clear anti-correlation with the chromospheric activity. The difference in brightness between the opposite hemispheres decreased from 0.m16 to 0.m09 in two months. Three spots gradually moving apart from each other are dominating the photospheric Doppler maps. The comparison between the maps and the Hα line as the star rotates reveals the spatial coexistence of chromospheric Hα emission and photospheric spots. Conclusions: Our results indicate that the active regions of LQ Hya can live for at least four months. The detected changes in the photometric light curve and the spectroscopic Doppler images seem to be more a consequence of the spatial redistribution of the active regions rather than due to changes in their strength. Only one of the active regions shows significant changes in its chromospheric emission. Based on data obtained with the STELLA robotic telescope in Tenerife, an AIP facility jointly operated by AIP

  12. Konstruowanie „ja” w twórczości Franciszka Karpińskiego na tle epoki i jej tendencji

    Directory of Open Access Journals (Sweden)

    Przemysław Górecki

    2014-04-01

    Full Text Available Constructing the self in the literary work of Franciszek Karpiński against the background of the Enlightenment and its tendencies The presented paper provides analysis of the notion ‘autobiographism’ contextualised in the literary output of the Polish poet of the enlightenment, Franciszek Karpiński. The question of autobiographism is presented in terms of the literature and philosophy of Jean Jacques Rousseau. This analysis of the phenomena of authenticity and autobiographicality is concerned with constructing oneself in literature as illustrated by certain works, with the primacy of the mundane The History Of My Age And People With Whom I Lived. The essay draws on The Confessions by Rousseau with a view to specifying the connections between these two novels. The consciousness of the impact Rousseau had on the European sense of literature breaks new ground in the interpretation of the legacy of Karpiński. It also enables the recognition of the complete and compact project situated on the verge of literature and philosophy. The breakthrough of this project is contained in the priority given to the Polish historical literary process and the novelty of the autobiographical attitude, which is considered through the application of basic conceptions concerning autobiographism and the modern identity project of the aesthetic human.   Konstruowanie „ja” w twórczości Franciszka Karpińskiego na tle epoki i jej tendencji Szkic poświęcony jest zagadnieniu autobiografizmu w twórczości Franciszka Karpińskiego ujmowanemu pod kątem jego związków z twórczością i filozofią Jana Jakuba Rousseau. Analiza zjawisk autentyczności i autobiograficzności dotyka kwestii konstruowania siebie w literaturze na przykładzie konkretnych utworów, z których najważniejszym jest przełomowa dla historii polskiej literatury powieść Karpińskiego Historia mego wieku i ludzi z którymi żyłem. Przedmiotem analizy są m.in. jej związki z Wyznaniami

  13. The simulations of charged particle acceleration from gas target at 20 TW SOKOL-P laser with intensity of 5⋅1019 W/cm2

    Directory of Open Access Journals (Sweden)

    Lykov V.A.

    2013-11-01

    Full Text Available 2D PIC code simulations have been performed for the optimization of gas jet target parameters to achieve a maximal energy and efficiency of charged particle acceleration in planned experiments at the 20 TW picosecond SOKOL-P laser. These calculations specify an opportunity to obtain energy up to Ee ∼ 200 MeV and efficiency ηe ∼ 10% for accelerated electrons and Ep ∼ 30 − 50 MeV and ηp ∼ 5% for accelerated protons in these experiments at laser intensity I ∼ 5 ⋅ 1019 W/cm2. They show the necessity of providing a formation of hydrogen jets with diameter ∼ 1mm, a gas molecule concentration ∼ 2 ⋅ 1019 cm−3 and steep density gradients ∼ 200 μm at the edge of the gas jet target for achieving these parameters of laser accelerated particle beams.

  14. Young Money

    DEFF Research Database (Denmark)

    Roelsgaard Obling, Anne

    2015-01-01

    Book review of: Kevin Roose: "Young Money: Inside the Hidden World of Wall Street's Post-Crash Recruits". New York: Grand Central Publishing, 2014. 320 pp.......Book review of: Kevin Roose: "Young Money: Inside the Hidden World of Wall Street's Post-Crash Recruits". New York: Grand Central Publishing, 2014. 320 pp....

  15. Sistema de prueba para la determinación de la capacitancia y permitividad relativa en cables de bajo voltaje del tipo TW y THW

    Directory of Open Access Journals (Sweden)

    Juan Almirall Mesa

    2011-02-01

    Full Text Available En los cables de baja tensión la comprobación de la calidad del material aislante de recubrimiento seefectúa a partir de la evaluación de parámetros eléctricos tales como: la resistencia de aislamiento y lacapacitancia del mismo. En el presente trabajo se expone el esquema de prueba, su calibración y elanálisis de la metodología de ensayo empleada, para medir la capacitancia de cables nacionales del tipoTW y THW. El esquema general de pruebas consta de dos partes fundamentales: el sistema de pruebapara la medición de los parámetros eléctricos y el sistema de control de temperatura y de nivel del líquidodonde se sumergen los cables para los ensayos, este último garantiza que los cambios de temperaturaen el mismo se mantengan en el rango establecido por las normas. La metodología tiene en cuenta ladeterminación del efecto que tienen las condiciones iniciales sobre los resultados finales.  The verification of the quality of the covering insulating material in low voltage cables is carried outbeginning whit the evaluation of electric parameters such as: insulating resistance and capacitance of thesame. In this work, the test scheme, its calibration and the analyses of the methodology of the employedtest, for measuring the national cables capacitance of the TW and THW type are exposed. The generalscheme of test consist in two fundamental parts: the test system for the measure of the electric parametersand the temperature and liquid level control system where the cables are immersed for the test, the lastsystem guarantee that the temperature changes in the same in the establish range by the standards aremaintained.The methodology taking into account the determination of the effect that has the startingconditions on the final results.

  16. Correlation and comparison of Risser sign versus bone age determination (TW3 between children with and without scoliosis in Korean population

    Directory of Open Access Journals (Sweden)

    Yang Jae-Hyuk

    2009-09-01

    Full Text Available Abstract Background Most studies comparing the Risser staging for skeletal maturity are representing the American or European standards which are not always applicable to Asian population who have relatively less height and body mass. There is no article available that compares the Risser sign and bone age correlation between patients with idiopathic scoliosis and patients without scoliosis. Materials and methods To analyze and compare the skeletal age with the Risser sign between scoliosis and non-scoliosis group, a cross-sectional study was done in 418 scoliosis (untreated, bracing or surgically and 256 non-scoliosis children of Korean origin. Relationship was found in both groups using Pearson correlation test. Results In scoliosis group, Pearson correlation exhibited significant correlation (p 2 = 0.791 for girls, 0.787 for boys and Risser sign and TW3 age (r2 = 0.718 for girls, 0.785 for boys. Non-scoliosis group also showed significant relationship (p 2 = 0.893 for girls, 0.879 for boys and Risser sign and TW3 age (r2 = 0.913 for girls, 0.895 for boys. Similarly, comparing Cobb angles of each patient according to their Risser staging, exhibited that if scoliosis remains untreated Cobb angle will increase with the increase in their Risser staging (r2 = 0.363 for girls, 0.443 for boys; p Conclusion Our results showed that chronological age is equally as reliable as skeletal age method to compare with Risser sign, and therefore, we do not mean to imply that only the Risser sign compared with skeletal age should be considered in the decision making in idiopathic as well as non-scoliosis patients of Korean ethnicity. Concomitant indicators such as menarchal period, secondary sex characteristics, and recent growth pattern will likely reinforce our data comparing Risser sign with skeletal age in decision making.

  17. Young Love

    OpenAIRE

    Regmi, Pramod; Simkhada, Padam; van Teijlingen, Edwin

    2010-01-01

    Your article on love and relationship deals with a very important issue (“Love makes the world go round,” Feb. 15, Page 1).It is now widely accepted that romantic relationships and dating are normative among adolescents and young people in Nepal. In our qualitative study of urban and rural young males and females using same sex researchers — in perhaps the first study of dating practice among Nepali youth — almost all of our respondents reported that young people in Nepal form partnerships wi...

  18. Mapping of the Pim-1 oncogene in mouse t-haplotypes and its use to define the relative map positions of the tcl loci t0(t6) and tw12 and the marker tf (tufted).

    Science.gov (United States)

    Ark, B; Gummere, G; Bennett, D; Artzt, K

    1991-06-01

    Pim-1 is an oncogene activated in mouse T-cell lymphomas induced by Moloney and AKR mink cell focus (MCF) viruses. Pim-1 was previously mapped to chromosome 17 by somatic cell hybrids, and subsequently to the region between the hemoglobin alpha-chain pseudogene 4 (Hba-4ps) and the alpha-crystalline gene (Crya-1) by Southern blot analysis of DNA obtained from panels of recombinant inbred strains. We have now mapped Pim-1 more accurately in t-haplotypes by analysis of recombinant t-chromosomes. The recombinants were derived from Tts6tf/t12 parents backcrossed to + tf/ + tf, and scored for recombination between the loci of T and tf. For simplicity all t-complex lethal genes properly named tcl-tx are shortened to tx. The Pim-1 gene was localized 0.6 cM proximal to the tw12 lethal gene, thus placing the Pim-1 gene 5.2 cM distal to the H-2 region in t-haplotypes. Once mapped, the Pim-1 gene was used as a marker for further genetic analysis of t-haplotypes. tw12 is so close to tf that even with a large number of recombinants it was not possible to determine whether it is proximal or distal to tf. Southern blot analysis of DNA from T-tf recombinants with a separation of tw12 and tf indicated that tw12 is proximal to tf. The mapping of two allelic t-lethals, t0 and t6 with respect to tw12 and tf has also been a problem.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Glycosaminoglycans in Hydra magnipapillata (Hydrozoa, Cnidaria): demonstration of chondroitin in the developing nematocyst, the sting organelle, and structural characterization of glycosaminoglycans.

    Science.gov (United States)

    Yamada, Shuhei; Morimoto, Hideto; Fujisawa, Toshitaka; Sugahara, Kazuyuki

    2007-08-01

    The hydrozoan is the simplest organism whose movements are governed by the neuromuscular system, and its de novo morphogenesis can be easily induced by the removal of body parts. These features make the hydrozoan an excellent model for studying the regeneration of tissues in vivo, especially in the nervous system. Although glycosaminoglycans (GAGs) and proteoglycans (PGs) have been implicated in the signaling functions of various growth factors and play critical roles in the development of the central nervous system, the isolation and characterization of GAGs from hydrozoans have never been reported. Here, we characterized GAGs of Hydra magnipapillata. Immunostaining using anti-GAG antibodies showed chondroitin or chondroitin sulfate (CS) in the developing nematocyst, which is a sting organelle specific to cnidarians. The CS-PGs might furnish an environment for assembling nematocyst components, and might themselves be components of nematocysts. Therefore, GAGs were isolated from Hydra and their structural features were examined. A considerable amount of CS, three orders of magnitude less heparan sulfate (HS), but no hyaluronan were found, as in Caenorhabditis elegans. Analysis of the disaccharide composition of HS revealed glucosamine 2-N-sulfation, glucosamine 6-O-sulfation, and uronate 2-O-sulfation. CS contains not only nonsulfated and 4-O-sulfated N-acetylgalactosamine (GalNAc) but also 6-O-sulfated GalNAc. The average molecular size of CS and HS was 110 and 10 kDa, respectively. It has also been established here that CS chains are synthesized on the core protein through the ubiquitous linkage region tetrasaccharide, suggesting that indispensable functions of the linkage region in the synthesis of GAGs have been conserved during evolution.

  20. Search for the production of an excited bottom quark decaying to tW in proton-proton collisions at $\\sqrt{s} =$ 8 TeV

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Aşılar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Knünz, Valentin; König, Axel; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Lauwers, Jasper; Luyckx, Sten; Ochesanu, Silvia; Rougny, Romain; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Van Parijs, Isis; Barria, Patrizia; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Delannoy, Hugo; Fasanella, Giuseppe; Favart, Laurent; Gay, Arnaud; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Léonard, Alexandre; Maerschalk, Thierry; Marinov, Andrey; Perniè, Luca; Randle-conde, Aidan; Reis, Thomas; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Crucy, Shannon; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Poyraz, Deniz; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Mertens, Alexandre; Nuttens, Claude; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Beliy, Nikita; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Hamer, Matthias; Hensel, Carsten; Mora Herrera, Clemencia; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; De Souza Santos, Angelo; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Cheng, Tongguang; Du, Ran; Jiang, Chun-Hua; Romeo, Francesco; Shaheen, Sarmad Masood; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Zhu, Shihai; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Zou, Wei; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Micanovic, Sasa; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Awad, Adel; El-khateeb, Esraa; Mohamed, Amr; Salama, Elsayed; Calpas, Betty; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Veelken, Christian; Eerola, Paula; Pekkanen, Juska; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Zghiche, Amina; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Chapon, Emilien; Charlot, Claude; Dahms, Torsten; Davignon, Olivier; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Lisniak, Stanislav; Mastrolorenzo, Luca; Miné, Philippe; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Regnard, Simon; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Chanon, Nicolas; Collard, Caroline; Conte, Eric; Coubez, Xavier; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Merlin, Jeremie Alexandre; Skovpen, Kirill; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Bouvier, Elvire; Carrillo Montoya, Camilo Andres; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Courbon, Benoit; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Xiao, Hong; Toriashvili, Tengizi; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Edelhoff, Matthias; Feld, Lutz; Heister, Arno; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Ostapchuk, Andrey; Preuten, Marius; Raupach, Frank; Schael, Stefan; Schulte, Jan-Frederik; Verlage, Tobias; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Künsken, Andreas; Lingemann, Joschka; Nehrkorn, Alexander; Nowack, Andreas; Nugent, Ian Michael; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Asin, Ivan; Bartosik, Nazar; Behnke, Olaf; Behrens, Ulf; Bell, Alan James; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dolinska, Ganna; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Gizhko, Andrii; Gunnellini, Paolo; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Karacheban, Olena; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Korol, Ievgen; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Nayak, Aruna; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Roland, Benoit; Sahin, Mehmet Özgür; Saxena, Pooja; Schoerner-Sadenius, Thomas; Schröder, Matthias; Seitz, Claudia; Spannagel, Simon; Trippkewitz, Karim Damun; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Gonzalez, Daniel; Görner, Martin; Haller, Johannes; Hoffmann, Malte; Höing, Rebekka Sophie; Junkes, Alexandra; Klanner, Robert; Kogler, Roman; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Marconi, Daniele; Meyer, Mareike; Nowatschin, Dominik; Ott, Jochen; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Pietsch, Niklas; Poehlsen, Jennifer; Rathjens, Denis; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schwandt, Joern; Seidel, Markus; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Vormwald, Benedikt; Akbiyik, Melike; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Fink, Simon; Frensch, Felix; Giffels, Manuel; Gilbert, Andrew; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Lobelle Pardo, Patricia; Maier, Benedikt; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Röcker, Steffen; Roscher, Frank; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Psallidas, Andreas; Topsis-Giotis, Iasonas; Agapitos, Antonis; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Tziaferi, Eirini; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Loukas, Nikitas; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Strologas, John; Bencze, Gyorgy; Hajdu, Csaba; Hazi, Andras; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Makovec, Alajos; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Mal, Prolay; Mandal, Koushik; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Chawla, Ridhi; Gupta, Ruchi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Anterpreet; Kaur, Manjit; Kumar, Ramandeep; Mehta, Ankita; Mittal, Monika; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Garg, Rocky Bala; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Nishu, Nishu; Ranjan, Kirti; Sharma, Ramkrishna; Sharma, Varun; Banerjee, Sunanda; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dey, Sourav; Dutta, Suchandra; Jain, Sandhya; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukherjee, Swagata; Mukhopadhyay, Supratik; Roy, Ashim; Roy, Debarati; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Bhowmik, Sandeep; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Mahakud, Bibhuprasad; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mitra, Soureek; Mohanty, Gagan Bihari; Parida, Bibhuti; Sarkar, Tanmay; Sudhakar, Katta; Sur, Nairit; Sutar, Bajrang; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Sharma, Seema; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Goldouzian, Reza; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Caputo, Claudio; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Abbiendi, Giovanni; Battilana, Carlo; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Lo Vetere, Maurizio; Monge, Maria Roberta; Robutti, Enrico; Tosi, Silvano; Brianza, Luca; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Esposito, Marco; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lanza, Giuseppe; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Azzi, Patrizia; Bacchetta, Nicola; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; Dall'Osso, Martino; Dorigo, Tommaso; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Passaseo, Marina; Pazzini, Jacopo; Pegoraro, Matteo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Zanetti, Marco; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Braghieri, Alessandro; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Biasini, Maurizio; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Spiezia, Aniello; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fedi, Giacomo; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; D'imperio, Giulia; Del Re, Daniele; Diemoz, Marcella; Gelli, Simone; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Micheli, Francesco; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Costa, Marco; Covarelli, Roberto; Dattola, Domenico; Degano, Alessandro; Demaria, Natale; Finco, Linda; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Musich, Marco; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Ravera, Fabio; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Schizzi, Andrea; Umer, Tomo; Zanetti, Anna; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Sakharov, Alexandre; Son, Dong-Chul; Brochero Cifuentes, Javier Andres; Kim, Hyunsoo; Kim, Tae Jeong; Ryu, Min Sang; Song, Sanghyeon; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Park, Sung Keun; Roh, Youn; Yoo, Hwi Dong; Choi, Minkyoo; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Ryu, Geonmo; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Donghyun; Kwon, Eunhyang; Lee, Jongseok; Yu, Intae; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Casimiro Linares, Edgar; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Reucroft, Steve; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Khurshid, Taimoor; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Leonardo, Nuno; Lloret Iglesias, Lara; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Konoplyanikov, Viktor; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Vlasov, Evgueni; Zhokin, Alexander; Bylinkin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Ekmedzic, Marko; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Soares, Mara Senghi; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Brun, Hugues; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Palencia Cortezon, Enrique; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Castiñeiras De Saa, Juan Ramon; De Castro Manzano, Pablo; Duarte Campderros, Jordi; Fernandez, Marcos; Garcia-Ferrero, Juan; Gomez, Gervasio; Graziano, Alberto; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Berruti, Gaia Maria; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Colafranceschi, Stefano; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; Daponte, Vincenzo; David Tinoco Mendes, Andre; De Gruttola, Michele; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Di Marco, Emanuele; Dobson, Marc; Dordevic, Milos; Dorney, Brian; Du Pree, Tristan; Dünser, Marc; Dupont, Niels; Elliott-Peisert, Anna; Franzoni, Giovanni; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Glege, Frank; Guida, Roberto; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kirschenmann, Henning; Kortelainen, Matti J; Kousouris, Konstantinos; Krajczar, Krisztian; Lecoq, Paul; Lourenco, Carlos; Lucchini, Marco Toliman; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Martelli, Arabella; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Nemallapudi, Mythra Varun; Neugebauer, Hannes; Orfanelli, Styliani; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Peruzzi, Marco; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Piparo, Danilo; Racz, Attila; Rolandi, Gigi; Rovere, Marco; Ruan, Manqi; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Sharma, Archana; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Steggemann, Jan; Stieger, Benjamin; Stoye, Markus; Takahashi, Yuta; Treille, Daniel; Triossi, Andrea; Tsirou, Andromachi; Veres, Gabor Istvan; Wardle, Nicholas; Wöhri, Hermine Katharina; Zagoździńska, Agnieszka; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; Kotlinski, Danek; Langenegger, Urs; Renker, Dieter; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Buchmann, Marco-Andrea; Casal, Bruno; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Eller, Philipp; Grab, Christoph; Heidegger, Constantin; Hits, Dmitry; Hoss, Jan; Kasieczka, Gregor; Lustermann, Werner; Mangano, Boris; Marini, Andrea Carlo; Marionneau, Matthieu; Martinez Ruiz del Arbol, Pablo; Masciovecchio, Mario; Meister, Daniel; Musella, Pasquale; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pata, Joosep; Pauss, Felicitas; Perrozzi, Luca; Quittnat, Milena; Rossini, Marco; Starodumov, Andrei; Takahashi, Maiko; Tavolaro, Vittorio Raoul; Theofilatos, Konstantinos; Wallny, Rainer; Aarrestad, Thea Klaeboe; Amsler, Claude; Caminada, Lea; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Galloni, Camilla; Hinzmann, Andreas; Hreus, Tomas; Kilminster, Benjamin; Lange, Clemens; Ngadiuba, Jennifer; Pinna, Deborah; Robmann, Peter; Ronga, Frederic Jean; Salerno, Daniel; Yang, Yong; Cardaci, Marco; Chen, Kuan-Hsin; Doan, Thi Hien; Jain, Shilpi; Khurana, Raman; Konyushikhin, Maxim; Kuo, Chia-Ming; Lin, Willis; Lu, Yun-Ju; Volpe, Roberta; Yu, Shin-Shan; Kumar, Arun; Bartek, Rachel; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Dietz, Charles; Fiori, Francesco; Grundler, Ulysses; Hou, George Wei-Shu; Hsiung, Yee; Liu, Yueh-Feng; Lu, Rong-Shyang; Miñano Moya, Mercedes; Petrakou, Eleni; Tsai, Jui-fa; Tzeng, Yeng-Ming; Asavapibhop, Burin; Kovitanggoon, Kittikul; Singh, Gurpreet; Srimanobhas, Norraphat; Suwonjandee, Narumon; Adiguzel, Aytul; Cerci, Salim; Demiroglu, Zuhal Seyma; Dozen, Candan; Dumanoglu, Isa; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Tali, Bayram; Topakli, Huseyin; Vergili, Mehmet; Zorbilmez, Caglar; Akin, Ilina Vasileva; Bilin, Bugra; Bilmis, Selcuk; Isildak, Bora; Karapinar, Guler; Surat, Ugur Emrah; Yalvac, Metin; Zeyrek, Mehmet; Yetkin, Elif Asli; Gülmez, Erhan; Kaya, Mithat; Kaya, Ozlem; Yetkin, Taylan; Cankocak, Kerem; Sen, Sercan; Vardarlı, Fuat Ilkehan; Grynyov, Boris; Levchuk, Leonid; Sorokin, Pavel; Aggleton, Robin; Ball, Fionn; Beck, Lana; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Meng, Zhaoxia; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Sakuma, Tai; Seif El Nasr-storey, Sarah; Senkin, Sergey; Smith, Dominic; Smith, Vincent J; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Thomas, Laurent; Tomalin, Ian R; Williams, Thomas; Womersley, William John; Worm, Steven; Baber, Mark; Bainbridge, Robert; Buchmuller, Oliver; Bundock, Aaron; Burton, Darren; Casasso, Stefano; Citron, Matthew; Colling, David; Corpe, Louie; Cripps, Nicholas; Dauncey, Paul; Davies, Gavin; De Wit, Adinda; Della Negra, Michel; Dunne, Patrick; Elwood, Adam; Ferguson, William; Fulcher, Jonathan; Futyan, David; Hall, Geoffrey; Iles, Gregory; Kenzie, Matthew; Lane, Rebecca; Lucas, Robyn; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Raymond, David Mark; Richards, Alexander; Rose, Andrew; Seez, Christopher; Tapper, Alexander; 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Polese, Giovanni; Ross, Ian; Ruggles, Tyler; Sarangi, Tapas; Savin, Alexander; Sharma, Archana; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Woods, Nathaniel

    2016-01-01

    A search is presented for a singly produced excited bottom quark ($\\mathrm{b}^*$) decaying to a top quark and a W boson in the all-hadronic, lepton+jets, and dilepton final states in proton-proton collisions at $\\sqrt{s} =$ 8 TeV recorded by the CMS experiment at the CERN LHC. Data corresponding to an integrated luminosity of 19.7 fb$^{-1}$ are used. No significant excess of events is observed with respect to standard model expectations. We set limits at 95% confidence on the product of the $\\mathrm{b}^*$ quark production cross section and its branching fraction to tW. The cross section limits are interpreted for scenarios including left-handed, right-handed, and vector-like couplings of the $\\mathrm{b}^*$ quark and are presented in the two-dimensional coupling plane based on the production and decay coupling constants. The masses of the left-handed, right-handed, and vector-like $\\mathrm{b}^*$ quark states are excluded at 95% confidence below 1390, 1430, and 1530 GeV, respectively, for benchmark couplings. T...

  1. Scheme for generation of fully-coherent, TW power level hard X-ray pulses from baseline undulators at the European X-ray FEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2010-01-01

    The most promising way to increase the output power of an X-ray FEL (XFEL) is by tapering the magnetic field of the undulator. Also, significant increase in power is achievable by starting the FEL process from a monochromatic seed rather than from noise. This report proposes to make use of a cascade self-seeding scheme with wake monochromators in a tunable-gap baseline undulator at the European XFEL to create a source capable of delivering coherent radiation of unprecedented characteristics at hard X-ray wavelengths. Compared with SASE X-ray FEL parameters, the radiation from the new source has three truly unique aspects: complete longitudinal and transverse coherence, and a peak brightness three orders of magnitude higher than what is presently available at LCLS. Additionally, the new source will generate hard X-ray beam at extraordinary peak (TW) and average (kW) power level. The proposed source can thus revolutionize fields like single biomolecule imaging, inelastic scattering and nuclear resonant scatteri...

  2. Proposal to generate 10 TW level femtosecond x-ray pulses from a baseline undulator in conventional SASE regime at the European XFEL

    CERN Document Server

    Serkez, Svitozar; Saldin, Evgeni; Zagorodnov, Igor; Geloni, Gianluca

    2013-01-01

    Output characteristics of the European XFEL have been previously studied assuming an operation point at 5 kA peak current. In this paper we explore the possibility to go well beyond such nominal peak current level. In order to illustrate the potential of the European XFEL accelerator complex we consider a bunch with 0.25 nC charge, compressed up to a peak current of 45 kA. An advantage of operating at such high peak current is the increase of the x-ray output peak power without any modification to the baseline design. Based on start-to-end simulations, we demonstrate that such high peak current, combined with undulator tapering, allows one to achieve up to a 100-fold increase in a peak power in the conventional SASE regime, compared to the nominal mode of operation. In particular, we find that 10 TW-power level, femtosecond x-ray pulses can be generated in the photon energy range between 3 keV and 5 keV, which is optimal for single biomolecule imaging. Our simulations are based on the exploitation of all the ...

  3. Proposal to generate 10 TW level femtosecond X-ray pulses from a baseline undulator in conventional SASE regime at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

    2013-08-15

    Output characteristics of the European XFEL have been previously studied assuming an operation point at 5 kA peak current. In this paper we explore the possibility to go well beyond such nominal peak current level. In order to illustrate the potential of the European XFEL accelerator complex we consider a bunch with 0.25 nC charge, compressed up to a peak current of 45 kA. An advantage of operating at such high peak current is the increase of the X-ray output peak power without any modification to the baseline design. Based on start-to-end simulations, we demonstrate that such high peak current, combined with undulator tapering, allows one to achieve up to a 100-fold increase in a peak power in the conventional SASE regime, compared to the nominal mode of operation. In particular, we find that 10 TW-power level, femtosecond x-ray pulses can be generated in the photon energy range between 3 keV and 5 keV, which is optimal for single biomolecule imaging. Our simulations are based on the exploitation of all the 21 cells foreseen for the SASE3 undulator beamline, and indicate that one can achieve diffraction to the desired resolution with 15 mJ (corresponding to about 3.10{sup 13} photons) in pulses of about 3 fs, in the case of a 100 nm focus at the photon energy of 3.5 keV.

  4. Efecto de las condiciones de crecimiento y composición del medio de cultivo sobre la producción de bacteriocina de Enterococcus mundtii Tw56

    Directory of Open Access Journals (Sweden)

    Marisol Vallejo

    2014-12-01

    Full Text Available Enterococcus mundtii Tw56 is a bacteriocin-producing strain that was isolated from intestinal content of silverside (Odontesthes sp.. The aim of the present work was to determine physicochemical factors and culture medium composition for higher yield of viable cells and bacteriocin production. No changes were observed in the antimicrobial production when glucose was replaced by fructose or maltose in the MRS medium formulation. On the other hand, highest bacteriocin activity was obtained when meat extract was used as a sole nitrogen source. While the maximun biomass was achieved at35 ºC, the optimal temperatures for bacteriocin production were observed at 25 and30 ºC. The optimal initial pH for cell growth and bioactivity was 6.5, both parameters dropped when the experience started at pH 6.0 or 5.5. Biomass formation and bacteriocin production decreased in the presence of sodium chloride. The strain started producing the bacteriocin at the late exponential phase. The activity increased as a function of the cell mass and reached the maximun at the end of exponential phase (12 h. A decrease of antimicrobial activity was observed in the stationary phase (16 h, possibly due to degradation by proteolitic enzimes.

  5. 长蛇灸治疗强直性脊柱炎中的护理安全管理%Nursing security management of hydra moxibustion treatment applied in patients with ankylosing spondylitis

    Institute of Scientific and Technical Information of China (English)

    熊丽萍; 龚小燕; 潘芳

    2011-01-01

    目的 探讨长蛇灸治疗强直性脊柱炎中的护理安全问题及其防范措施,防止不良并发症发生.方法 对患者施灸前做好充分的灸前准备,并针对治疗中容易发生的皮肤过敏及感染、烫伤、晕厥等安全问题进行积极防范以及灸后的护理干预.结果 38例患者无并发症发生,保障了患者安全.结论 针对长蛇灸治疗强直性脊柱炎中的护理安全问题积极防范,可以保障患者安全.%Objective To explore nursing safety problems and management strategies of hydra moxibustion treatment applied in patients with ankyiosing spondylitis, so as to prevent the occurrence of adverse complications. Methods Adequate preparation was done before hydra moxibustion treatment, and the problems, which were easy to occur during the treatment,such as skin allergies and infections,burns,syncope and other safety issues, were prevented actively,and nursing interventions after hydra moxibustion treatment were strengthened. Result No adverse complications happened in 38 patients, and the safty of patients was protected. Conclusion Positive prevention of nursing security problems during hydra moxibustion treatment can enhance the safety of patients.

  6. Horizontal gene transfer contributed to the evolution of extracellular surface structures: the freshwater polyp Hydra is covered by a complex fibrous cuticle containing glycosaminoglycans and proteins of the PPOD and SWT (sweet tooth families.

    Directory of Open Access Journals (Sweden)

    Angelika Böttger

    Full Text Available The single-cell layered ectoderm of the fresh water polyp Hydra fulfills the function of an epidermis by protecting the animals from the surrounding medium. Its outer surface is covered by a fibrous structure termed the cuticle layer, with similarity to the extracellular surface coats of mammalian epithelia. In this paper we have identified molecular components of the cuticle. We show that its outermost layer contains glycoproteins and glycosaminoglycans and we have identified chondroitin and chondroitin-6-sulfate chains. In a search for proteins that could be involved in organising this structure we found PPOD proteins and several members of a protein family containing only SWT (sweet tooth domains. Structural analyses indicate that PPODs consist of two tandem β-trefoil domains with similarity to carbohydrate-binding sites found in lectins. Experimental evidence confirmed that PPODs can bind sulfated glycans and are secreted into the cuticle layer from granules localized under the apical surface of the ectodermal epithelial cells. PPODs are taxon-specific proteins which appear to have entered the Hydra genome by horizontal gene transfer from bacteria. Their acquisition at the time Hydra evolved from a marine ancestor may have been critical for the transition to the freshwater environment.

  7. 大豆突变体Gm-lpa-TW-1中低植酸性状与种子发芽率和糖份含量的相关性分析%RELATIONSHIP OF LOW PHYTATE TRAIT WITH SEED GERMINATION AND CARBOHYDRATES CONTENT IN SOYBEAN MUTANT Gm-lpa-TW-1

    Institute of Scientific and Technical Information of China (English)

    袁凤杰; 董德坤; 李百权; 傅旭军; 朱丹华; 朱申龙

    2011-01-01

    为明确低植酸突变体Gm-lpa-TW-1植酸性状突变与种子发芽率降低以及糖份含量变化的相关性,选用低植酸突变体Gm-lpa-TW-1与不同野生型亲本的杂交后代,低植酸纯合株系(LPA)和非低植酸纯合株系(HPA)为研究材料,分析不同株系在不同种植环境下收获种子的发芽率、总糖、蔗糖和低聚糖的含量。结果表明:无论是LPA株系还是HPA株系春播种子的发芽率均显著低于秋播种子;同一杂交组合中LPA株系春播种子的发芽率显著低于HPA株系春播种子;鲜食大豆杂交组合后代的LPA株系发芽率低于粒用大豆杂交组合的LPA株系;但在所有杂交组合后代株系中均可以筛选到发芽率显著高于突变亲本Gm-lpa-TW-1的LPA株系。糖份含量分析表明:LPA和HPA株系之间总糖含量无明显差异;LPA株系的蔗糖含量极显著地高于HPA株系的蔗糖含量,低聚糖含量则表现为极显著低于HPA株系,3种糖份含量在LPA和HPA株系之间的差异不受种植环境影响。LPA株系种子发芽率受到突变基因与环境互作的影响,高温环境对LPA株系种子的发芽率影响较大;通过遗传改良可以有效改善LPA突变基因对种子发芽率的不良影响。LPA株系中的低植酸性状与高蔗糖低寡聚糖性状表现为连锁遗传,有利于选育品质更为优良的大豆新品种。%The relationship between the low phytate mutation with seed germination and carbohydrate content homozygous F5 lines with/without lpagene derived from mutant and different wild type parents were analyzed.The results showed that LPA(low phytic acid)/HPA(high phytic aicd) lines developed in autumn had higher seed germination rate than that developed in spring.LPA lines had lower seed germination rate than HPA lines when they all developed in spring.However,in all crosses LPA lines with higher seed germination rate than mutant parent Gm-lpa-TW-1 was observed.No significant difference was

  8. A Chandra study of the large-scale shock and cool filaments in Hydra A: Evidence for substantial gas dredge-up by the central outburst

    CERN Document Server

    Gitti, Myriam; David, Laurence P; McNamara, Brian R; Wise, Michael W

    2011-01-01

    We present the results of a Chandra study of the Hydra A galaxy cluster, where a powerful AGN outburst created a large-scale cocoon shock. We investigated possible azimuthal variations in shock strength and shape, finding indications for a weak shock with a Mach number in the range ~1.2-1.3. We measured the temperature change across the shock front. However, the detection of a temperature rise in the regions immediately inside of the front is complicated by the underlying temperature profile of the cluster atmosphere. We measured the global temperature profile of the cluster up to 700 kpc, which represents the farthest measurement obtained with Chandra for this cluster. A "plateau" in the temperature profile in the range ~70-150 kpc indicates the presence of cool gas, which is likely the result of uplift of material by the AGN outburst. After masking the cool filaments visible in the hardness ratio map, the plateau disappears and the temperature profile recovers a typical shape with a peak around 190 kpc, jus...

  9. Experiment and Simulation Study on Generation of Monoenergetic Electron with Ultra-small NDA from 2 TW Laser Facility%利用2 TW 激光器产生具有超小归一化发散角的准单能电子束团的实验和模拟研究

    Institute of Scientific and Technical Information of China (English)

    李大章; 高杰

    2015-01-01

    利用2TW、80fs激光脉冲和等离子体相互作用,产生了能量为(23.0±0.8)MeV、电量为6pC的准单能电子束。该电子束的归一化发散角只有92 m rad ,较之前激光等离子体加速领域所获得的实验结果至少小了5倍以上。二维数值模拟结果显示,此结果的产生归功于加速机制上从自调制激光尾场加速向激光尾场加速的平稳过渡。%Monoenergetic electron beams with the energy of (23.0 ± 0.8) MeV and the charge of 6 pC were generated by using 2 TW and 80 fs laser pulses interacting with underdense plasmas .The beam’s normalized divergence angle is merely 92 mrad ,which is at least 5 times smaller than the published laser plasma acceleration experiment results .2D simulation and experiment data analysis results show that the significant improvement is due to the smooth transfer from self modulated laser wakefield accelera‐tion to laser wakefield acceleration .

  10. Empowering young people/ young adults to action

    DEFF Research Database (Denmark)

    Brander, Birgitte Gade

    2014-01-01

    Research questions: How do the young students relate to their community? How do young students position themselves as agents in their own lives and in the places they live – which discourse is used?......Research questions: How do the young students relate to their community? How do young students position themselves as agents in their own lives and in the places they live – which discourse is used?...

  11. Young Adult Literature for Young Adult Males.

    Science.gov (United States)

    Gill, Sam D.

    1999-01-01

    Argues that young adult literature can play a significant role in the emotional and mental health of an adolescent as well as help young males become more literate. Offers a 19-item annotated list of young adult novels with male protagonists, sorted by themes: nature and adventure stories, sports stories, genre stories, historical stories, and…

  12. Performance tests of the 5 TW, 1 kHz, passively CEP-stabilized ELI-ALPS SYLOS few-cycle laser system (Conference Presentation)

    Science.gov (United States)

    Stanislauskas, Tomas; Budriūnas, Rimantas; Veitas, Gediminas; Gadonas, Darius; Adamonis, Jonas; Aleknavičius, Aidas; Masian, Gžegož; Kuprionis, Zenonas; Hoff, Dominik; Paulus, Gerhard G.; Börzsönyi, Ádám.; Toth, Szabolcs; Kovacs, Mate; Csontos, János; López-Martens, Rodrigo; Osvay, Károly

    2017-05-01

    ELI-ALPS in Hungary, one of the three pillars of the Extreme Light Infrastructure, aims at providing diverse light sources, including energetic attosecond pulses at the highest possible repetition rates. One of the main laser systems for driving plasma and gas-based HHG stages, is a state-of-the-art 1 kHz few-cycle laser called SYLOS. Targeted pulse parameters are an energy of 100 mJ and a duration shorter than two optical cycles (energy, phase and pointing stability as well as high spatiotemporal quality. The first phase of the laser system has already set a new standard in kHz laser system engineering and technology. The performance and reliability of the SYLOS laser have been consistently tested over the course of a six-month trial period. During this time the system was running at least 8 hours a day at full power for more than 5 months. The current output parameters are 5 TW peak power, 45 mJ pulse energy with 9 fs duration and 300 mrad CEP stability, while the spectrum spans over 300 nm around 840 nm central wavelength. The layout follows the general scheme NOPCPA architecture with a passively CEP-stabilized front-end. The pulses are negatively chirped for the amplification process and compressed by a combination of large aperture bulk glass blocks and positively chirped mirrors under vacuum conditions at the output. During the trial period, the laser system demonstrated outstanding reliability. Daily startup and shutdown procedures take only a few minutes, and the command-control system enables pulse parameters to be modified instantly. Controlling the delays of individual NOPCPA stages makes it possible to tailor the output spectrum of the pulses and tune the central wavelength between 770 nm and 940 nm. We performed several experimental tests to find out the pulse characteristics. Pulse duration was verified with Wizzler, chirp-scan, autocorrelation methods and a stereo-ATI independently. All of them confirmed the sub-9 fs pulse duration. We recorded the

  13. Evolved Models for Elementary Particles and Atoms Require Alternating Neutrino/Antineutrino Pairs Along Interlocked or Looped Strings. Traveling Waves, TW, and Standing Waves, SW, Alternate at Nodal Notches

    Science.gov (United States)

    McLeod, Roger David; McLeod, David Matthew

    2009-05-01

    Our hydrogen atom interacts with a neutron star. Its stringy TW/SW electron is cut by a neutrino scissor that instantly becomes its end anti-node. The string has one extra neutrino in 100,000. Antimatter remains concealed. Our Dumbo Proton of a TW state is similarly cut. Inside the star, electron string/spring compresses 100,000 and 1836 times more, to proton's linear mass density. Electrostatics encourages that caboose, stringy electron, to couple with a cut proton. Linear charge densities neutralize while composite length contracts 20%. The writhing string evicts an antineutrino at closure on Pauli's authority, becoming Mickey Neutron, with looped quarks. Unstable Mickey Neutron has his ear notch forced into an ear notch of stable Dumbo Proton, achieving immortality in this deuteron marriage. Tritium is in a m'enage a trois. Alpha Nucleus has a # grid. Meta state Ne-20 predicts alpha eviction to O-16. Schr"odinger finally prevails, so string theory and Wave Mechanics can prosper.

  14. ADHD in Young Children

    Science.gov (United States)

    ... Digital Press Kit Read the MMWR Science Clips ADHD in Young Children Use recommended treatment first Language: ... The recommended first treatment for young children with ADHD is underused. The American Academy of Pediatrics recommends ...

  15. Extension of self-seeding scheme with single crystal monochromator to lower energy < 5 keV as a way to generate multi-TW scale pulses at the European XFEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2012-01-01

    We propose a use of the self-seeding scheme with single crystal monochromator to produce high power, fully-coherent pulses for applications at a dedicated bio-imaging beamline at the European X-ray FEL in the photon energy range between 3.5 keV and 5 keV. We exploit the C(111) Bragg reflection (pi-polarization) in diamond crystals with a thickness of 0.1 mm, and we show that, by tapering the 40 cells of the SASE3 type undulator the FEL power can reach up to 2 TW in the entire photon energy range. The present design assumes the use of a nominal electron bunch with charge 0.1 nC at nominal electron beam energy 17.5 GeV. The main application of the scheme proposed in this work is for single shot imaging of individual protein molecules.

  16. Phase-matched four-wave mixing of sub-100-TW/ cm2 femtosecond laser pulses in isolated air-guided modes of a hollow photonic-crystal fiber.

    Science.gov (United States)

    Konorov, S O; Serebryannikov, E E; Akimov, D A; Ivanov, A A; Alfimov, M V; Zheltikov, A M

    2004-12-01

    Hollow-core photonic-crystal fibers are shown to allow propagation and nonlinear-optical frequency conversion of high-intensity ultrashort laser pulses in the regime of isolated guided modes confined in the hollow gas-filled fiber core. With a specially designed dispersion of such modes, the 3omega=2omega+2omega-omega four-wave mixing of fundamental (omega) and second-harmonic (2omega) sub-100- TW/ cm(2) femtosecond pulses of a Cr:forsterite laser can be phase matched in a hollow photonic-crystal fiber within a spectral band of more than 10 nm, resulting in the efficient generation of femtosecond pulses in a well-resolved higher-order air-guided mode of 417-nm radiation.

  17. WEB法儿童成年身高预测系统的实用性研究%A web system based on TW2 method in prediction of adult height for children

    Institute of Scientific and Technical Information of China (English)

    邹诚实; 陈建列; 董静波; 何广友; 郭秧君; 方略; 邢红卫; 张兆国

    2012-01-01

    Objective To evaluate the application of an user-friendly web system based on TW2 method in predicting adult height for children. Methods The equations were programmed with a java-script language in an available web system of assessment of skeletal maturity. Three hundred cases were analyzed by this new web system and manual method. The adult height was predicted and children growth chart was generated based on time of birth, sex, time of menarche (female), height, parental height, and R series of skeletal age derived from the web system of assessment of skeletal maturity,. The substitutability of the two methods was analyzed by Bland-Altman chart. The consistency of the results of the two methods in predicting adult height in childhood was compared (u test). Results Three hundred cases were studied by two skilled radiologists using both web system and manual method; the results were compared. With the web system, 94.0% predictions (282/300) were the same, the difference was within +/- 1cm in 12 cases (4%) and within +/- 2cm in 6 cases(2%). With the manual method, 75.3%(226/300) predictions was the same, the difference within +/- 1cm in 30 cases(10%),within +/- 2cm in 28 cases(9.3%), within +/- 3cm in 9 cases (3.0%), within +/- 4cm in 4 cases (1.3%), and within +/- 5cm in 3 cases (1.0%). TW2 web system was significantly better than manual method (u=6.3462,P<0.05) and more effective. Conclusion The method developed in the study provides an easy and quick prediction of adult height in childhood, which can be used for clinical evaluation of child growth.%目的 研究一种简单实用的基于TW2骨龄的WEB法儿童成年身高预测系统来代替人工法进行儿童成年身高预测.方法 用JAVA脚本执行语言在现有TW2骨龄检测系统基础上编写基于TW2骨龄的成年身高预测公式,通过访问集成有以上算法的可视化WEB页面,根据TW2骨龄检测系统计算300例受检儿童X线骨龄片得到的R骨龄,结合输入的出生日期

  18. Fundamentals, current state of the development of, and prospects for further improvement of the new-generation thermal-hydraulic computational HYDRA-IBRAE/LM code for simulation of fast reactor systems

    Science.gov (United States)

    Alipchenkov, V. M.; Anfimov, A. M.; Afremov, D. A.; Gorbunov, V. S.; Zeigarnik, Yu. A.; Kudryavtsev, A. V.; Osipov, S. L.; Mosunova, N. A.; Strizhov, V. F.; Usov, E. V.

    2016-02-01

    The conceptual fundamentals of the development of the new-generation system thermal-hydraulic computational HYDRA-IBRAE/LM code are presented. The code is intended to simulate the thermalhydraulic processes that take place in the loops and the heat-exchange equipment of liquid-metal cooled fast reactor systems under normal operation and anticipated operational occurrences and during accidents. The paper provides a brief overview of Russian and foreign system thermal-hydraulic codes for modeling liquid-metal coolants and gives grounds for the necessity of development of a new-generation HYDRA-IBRAE/LM code. Considering the specific engineering features of the nuclear power plants (NPPs) equipped with the BN-1200 and the BREST-OD-300 reactors, the processes and the phenomena are singled out that require a detailed analysis and development of the models to be correctly described by the system thermal-hydraulic code in question. Information on the functionality of the computational code is provided, viz., the thermalhydraulic two-phase model, the properties of the sodium and the lead coolants, the closing equations for simulation of the heat-mass exchange processes, the models to describe the processes that take place during the steam-generator tube rupture, etc. The article gives a brief overview of the usability of the computational code, including a description of the support documentation and the supply package, as well as possibilities of taking advantages of the modern computer technologies, such as parallel computations. The paper shows the current state of verification and validation of the computational code; it also presents information on the principles of constructing of and populating the verification matrices for the BREST-OD-300 and the BN-1200 reactor systems. The prospects are outlined for further development of the HYDRA-IBRAE/LM code, introduction of new models into it, and enhancement of its usability. It is shown that the program of development and

  19. [Vulvovaginitis in young girls].

    Science.gov (United States)

    Olejek, Anita; Kellas-Sleczka, Sylwia; Kozak-Darmas, Iwona; Bilska, Anna; Zamłyński, Jacek; Horak, Stanisław; Nowak, Leszek

    2009-12-01

    Vulvovaginitis is the most common cause of gynecological complaints in young girls. Factors which cause vulvovaginitis include, among other things, low level of sexual hormones (hypoestrogenism), the anatomical proximity of the rectum and delicate vulvar skin and vaginal mucosa. Usually vulvovaginitis in young girls is caused by non-specific factors. The aim of the study was to present the most frequent causes of vulvovaginitis in young girls.

  20. Precise Infrared Radial Velocities from Keck/NIRSPEC and the Search for Young Planets

    CERN Document Server

    Bailey, John I; Blake, Cullen H; Charbonneau, Dave; Barman, Travis S; Tanner, Angelle M; Torres, Guillermo

    2012-01-01

    We present a high-precision infrared radial velocity study of late-type stars using spectra obtained with NIRSPEC at the W. M. Keck Observatory. Radial velocity precisions of 50 m/s are achieved for old field mid-M dwarfs using telluric features for precise wavelength calibration. Using this technique, 20 young stars in the {\\beta} Pic (age ~12 Myr) and TW Hya (age ~8 Myr) Associations were monitored over several years to search for low mass companions; we also included the chromospherically active field star GJ 873 (EV Lac) in this survey. Based on comparisons with previous optical observations of these young active stars, radial velocity measurements at infrared wavelengths mitigate the radial velocity noise caused by star spots by a factor of ~3. Nevertheless, star spot noise is still the dominant source of measurement error for young stars at 2.3 {\\mu}m, and limits the precision to ~77 m/s for the slowest rotating stars (v sin i 12 km/s). The observations reveal both GJ 3305 and TWA 23 to be single-lined...

  1. Evolution for Young Victorians

    Science.gov (United States)

    Lightman, Bernard

    2012-01-01

    Evolution was a difficult topic to tackle when writing books for the young in the wake of the controversies over Darwin's "Origin of Species." Authors who wrote about evolution for the young experimented with different ways of making the complex concepts of evolutionary theory accessible and less controversial. Many authors depicted presented…

  2. Young novice drivers.

    NARCIS (Netherlands)

    2013-01-01

    In The Netherlands, young novice drivers (18-24 years of age) show a crash rate that is five times higher than that of experienced drivers (30-59 years of age). The rate of young males is even seven times as high. The main reasons are lack of driving experience and hazardous behaviour typical of ado

  3. Evolution for Young Victorians

    Science.gov (United States)

    Lightman, Bernard

    2012-01-01

    Evolution was a difficult topic to tackle when writing books for the young in the wake of the controversies over Darwin's "Origin of Species." Authors who wrote about evolution for the young experimented with different ways of making the complex concepts of evolutionary theory accessible and less controversial. Many authors depicted presented…

  4. Young skateboarders their everyday

    Directory of Open Access Journals (Sweden)

    Marcelo Rampazzo

    2016-09-01

    Full Text Available In this research, we focus on young people and their daily lives, bringing elements discussing leisure, family, education and work. Research conducted with a group of young skaters in a public track skating in the city of Porto Alegre - RS. In a total nine months of direct observation, each reported in Field Diaries. We seek to understand how the leisure of young people who gave the practice of skateboarding, was related to other aspects of their daily lives. After completing the work, we consider that - to remain in practice the skateboard - young people needed to reconcile the charges of their families, in addition to labels and stereotypes imposed from "outside" the universe of practitioners of this sport. We noticed also that young people go through all this in order to keep their "projects" on the skateboard.

  5. Young-Old

    DEFF Research Database (Denmark)

    Simpson, Deane

    Young-Old examines contemporary architectural and urban mutations that have emerged as a consequence of one of the key demographic transformations of our time: aging populations. Distinguishing between different phases of old age, the book identifies the group known as the “young old” as a remark......Young-Old examines contemporary architectural and urban mutations that have emerged as a consequence of one of the key demographic transformations of our time: aging populations. Distinguishing between different phases of old age, the book identifies the group known as the “young old......” as a remarkable petri dish for experiments in subjectivity, collectivity, and environment. In investigating this field of latent urban and architectural novelty, Young-Old asserts both the escapist and emancipatory dimensions of these practices. Illustrated with drawings, maps, and photographs, the volume...... of Japan....

  6. Hypertension in young adults.

    Science.gov (United States)

    De Venecia, Toni; Lu, Marvin; Figueredo, Vincent M

    2016-01-01

    Hypertension remains a major societal problem affecting 76 million, or approximately one third, of US adults. While more prevalent in the older population, an increasing incidence in the younger population, including athletes, is being observed. Active individuals, like the young and athletes, are viewed as free of diseases such as hypertension. However, the increased prevalence of traditional risk factors in the young, including obesity, diabetes mellitus, and renal disease, increase the risk of developing hypertension in younger adults. Psychosocial factors may also be contributing factors to the increasing incidence of hypertension in the younger population. Increased left ventricular wall thickness and mass are increasingly found in young adults on routine echocardiograms and predict future cardiovascular events. This increasing incidence of hypertension in the young calls for early surveillance and prompt treatment to prevent future cardiac events. In this review we present the current epidemiological data, potential mechanisms, clinical implications, and treatment of hypertension in young patients and athletes.

  7. submitter Search for pair-produced heavy fourth-generation bottom-like quarks decaying to bZ and tW in 8,TeV proton-proton collisions with multilepton final states

    CERN Document Server

    Arora, Sanjay R

    We present a search for anomalous production of events with three or more isolated leptons produced in proton-proton collisions at 8 TeV collected by the CMS experiment at the LHC. We analyze 9.2 /fb of data collected by the CMS experiment during the 2012 LHC run. We categorize observed multilepton events into exclusive search channels based on various quantities based on the identity and kinematics of the objects in the events. The search channels are ordered by the amount of expected Standard Model background. Explicit use of requirements such as missing transverse energy or total hadronic energy is avoided. We emphasize data-based estimation of the Standard Model backgrounds, but also use simulation to estimate some of the backgrounds when appropriate. We interpret search results in the context of a model involving the exotic bottom-like quark bprime decaying to two different modes bZ and tW with varying branching ratios. We derive exclusion limits as a function of the bprime mass as well as the branching ...

  8. Young drivers and their young passengers.

    NARCIS (Netherlands)

    2015-01-01

    More than one-third of all fatalities among car passengers occurs in the 10-24-year age group. The majority of these young passengers die in a car driven by an 18 to 24-year old. Compared with the composition of the population, these are high proportions, yet the exposure (for example in distance tr

  9. Young drivers and their young passengers.

    NARCIS (Netherlands)

    2015-01-01

    More than one-third of all fatalities among car passengers occurs in the 10-24-year age group. The majority of these young passengers die in a car driven by an 18 to 24-year old. Compared with the composition of the population, these are high proportions, yet the exposure (for example in distance

  10. Young drivers and their young passengers.

    NARCIS (Netherlands)

    2015-01-01

    More than one-third of all fatalities among car passengers occurs in the 10-24-year age group. The majority of these young passengers die in a car driven by an 18 to 24-year old. Compared with the composition of the population, these are high proportions, yet the exposure (for example in distance tr

  11. From a Girl to a Young Woman.

    Science.gov (United States)

    Population Education Newsletter and Forum, 1987

    1987-01-01

    Describes a 27-part flip chart developed in the Marshall Islands which was designed to be used with sixth graders in an effort to prevent teenage pregnancy. Examples of various parts of the materials are included, along with discussion questions. (TW)

  12. Screening of Native Rotifers, Hydra, Planaria for Deriving Aquatic Life Criteria%水生生物水质基准研究中轮虫、水螅、涡虫类受试生物的筛选

    Institute of Scientific and Technical Information of China (English)

    郑欣; 闫振广; 刘征涛; 刘婷婷; 王晓南; 武江越; 王伟莉

    2015-01-01

    轮虫、水螅、涡虫是水生生态系统的重要生物类群.因其对水体污染较敏感,所以对水生生物基准研究有重要意义.依据我国生物区系资料及毒性数据丰度,筛选出8种代表性本土轮虫、水螅、涡虫类生物.参照美国水生生物基准技术指南,搜集、筛选了这8种代表性生物的急性毒性数据,通过数据分析,筛选出对各物种毒性最大的污染物,主要包括重金属、农药、有机锡化物、表面活性剂、吡啶胺类杀菌剂.分析污染物的物种敏感度分布,依据累积概率对代表性生物的物种敏感性进行分类,结果为:萼花臂尾轮虫(Brachionus calyciflorus)、绿水螅(Hydrav iridissima)、普通水螅(Hydra vulgaris)对重金属铜的累积概率为6.5%、85%和10.4%,普通水螅(Hydra vulgaris)对重金属汞的累积概率为6.3%;龟甲轮虫(Keratella cochlearis)和四齿腔轮虫(Lecane quadridentata)对五氯酚钠的累积概率为5.1%和7.6%;褐水螅(Hydrao ligactis)和绿水螅(Hydra viridissima)对三丁基氧化锡的累积概率为6.9%和13.8%,萼花臂尾轮虫(Brachionus calyciflorus)对氟啶胺的累积概率为6.7%,日本三角涡虫(Dugesia japonica)对四氯化碳、十二烷基苯磺酸钠的累积概率分别为6.7%和7.1%.上述结果表明:萼花臂尾轮虫、绿水螅对重金属铜敏感;普通水螅对重金属铜和汞敏感;龟甲轮虫和四齿腔轮虫对农药敏感;褐水螅和绿水螅对有机锡化物敏感;萼花臂尾轮虫对吡啶胺类杀菌剂敏感;日本三角涡虫对四氯化碳、表面活性剂敏感.这7种代表性生物可作为相关污染物的水生生物基准受试物种.

  13. Gas in Protoplanetary Discs (GASPS) 1. First results

    CERN Document Server

    Mathews, G S; Williams, J P; Howard, C D; Meeus, G; Riaz, B; Roberge, A; Sandell, G; Vandenbussche, B; Duchêne, G; Kamp, I; Ménard, F; Montesinos, B; Pinte, C; Thi, W F; Woitke, P; Alacid, J M; Andrews, S M; Ardila, D R; Aresu, G; Augereau, J C; Barrado, D; Brittain, S; Ciardi, D R; Danchi, W; Eiroa, C; Fedele, D; Grady, C A; de Gregorio-Monsalvo, I; Heras, A; Huelamo, N; Krivov, A; Lebreton, J; Liseau, R; Martin-Zaidi, C; Mendigutía, I; Mora, A; Morales-Calderon, M; Nomura, H; Pantin, E; Pascucci, I; Phillips, N; Podio, L; Poelman, D R; Ramsay, S; Rice, K; Riviere-Marichalar, P; Solano, E; Tilling, I; Walker, H; White, G J; Wright, G

    2010-01-01

    Context - Circumstellar discs are ubiquitous around young stars, but rapidly dissipate their gas and dust on timescales of a few Myr. The Herschel space observatory allows for the study of the warm disc atmosphere, using far-infrared spectroscopy to measure gas content and excitation conditions, and far-IR photometry to constrain the dust distribution. Aims - We aim to detect and characterize the gas content of circumstellar discs in four targets as part of the Herschel science demonstration phase. Methods - We carried out sensitive medium resolution spectroscopy and high sensitivity photometry at lambda ~60-190 micron using the Photodetector Array Camera and Spectrometer instrument on the Herschel space observatory. Results - We detect [OI] 63 micron emission from the young stars HD 169142, TW Hydrae, and RECX 15, but not HD 181327. No other lines, including [CII] 158 and [OI] 145, are significantly detected. All four stars are detected in photometry at 70 and 160 micron. Extensive models are presented in as...

  14. Reintegration of young mothers

    Directory of Open Access Journals (Sweden)

    Miranda Worthen

    2012-08-01

    Full Text Available Young mothers seeking reintegration after periods of time spent livingwith fighting forces and armed groups face exclusion and stigmarather than the support they and their children badly need.

  15. Young Adult Books.

    Science.gov (United States)

    Epstein, Connie C.

    1987-01-01

    Considers the similarities between science fiction writing and young adult literature, and points out that several well-known authors, such as Robert Heinlein and Jane Yolen, write in both genres. (NKA)

  16. Young Adult Books.

    Science.gov (United States)

    Rochman, Hazel

    1986-01-01

    Applies the idea of the theme booktalk to "Wuthering Heights," which serves as a springboard for talking about themes of family rage, confrontation, quarrel and rebellion in other works of literature with relevance to contemporary young people. (JK)

  17. [Excretory azoospermia: Young's syndrome].

    Science.gov (United States)

    Arrufat, J M; Cervelló, E; Albella, F

    1980-01-01

    The authors present a case of excretory azoospermia, whose deferentovesiculography and surgical exploration of the epididymis were normal. The patient presented bronchio-estasis and sinusitis as a result of which he was diagnosed as suffering from Young's syndrome. The authors make a review of the current state of the problem stressing the differences between Young's syndrome and immobile cilia syndrome described by Eliasson and colls.

  18. ECNS '99 - Young scientists forum

    DEFF Research Database (Denmark)

    Ceretti, M.; Janssen, S.; McMorrow, D.F.

    2000-01-01

    The Young Scientists Forum is a new venture for ECNS and follows the established tradition of an active participation by young scientists in these conferences. At ECNS '99 the Young Scientists Forum brought together 30 young scientists from 13 European countries. In four working groups...

  19. Motywy wędrówki dusz i dybuka w kulturze żydowskiej i ich współczesna realizacja w twórczości Jony Wolach

    Directory of Open Access Journals (Sweden)

    Anna Piątek

    2016-06-01

    Full Text Available Motifs of transmigration of souls and dybbuk in Jewish culture and their contemporary implementation in the works by Yona Wollach This article describes two concepts important for Jewish mysticism – dybbuk and the transmigration of soul, and goes on to present their contemporary usage in the works by Yona Wollach. The concept of the transmigration of souls (in Hebrew: gilgul neshamot describes a situation whereby the soul of a dead person returns to the this world and occupies a new body. In the case of the dybbuk (in Hebrew: dibuk, on the other hand, the body of a living person, who has his or her own soul, is possessed by the spirit of a dead person. The concepts of reincarnation and dybbuk played an important role not only in religious tradition but also in folklore and popular and high culture. Both became the focus of a number of artworks. The article presents fragments of the poems of the Israeli poet Yona Wollach (1944–1985, in which she describes psychological states similar to transmigration of souls and being captured by a dybbuk. The article aims to show that these poetic images are in close connection with Wollach`s concept of the human psyche.   Motywy wędrówki dusz i dybuka w kulturze żydowskiej i ich współczesna realizacja w twórczości Jony Wolach Artykuł przybliża dwa ważne pojęcia mistyki żydowskiej – dybuka i wędrówki dusz, a następnie ukazuje współczesne nawiązanie do nich w twórczości Jony Wolach. Pod pojęciem wędrówki dusz (hebr. gilgul neszamot rozumie się sytuację, w której dusza zmarłego wraca do świata doczesnego i zamieszkuje w nowym ciele. Natomiast w przypadku dybuka (hebr. dibuk dochodzi do zawładnięcia ciałem żywego człowieka, posiadającego już jedną duszę, przez ducha zmarłej wcześniej osoby. Pojęcia wędrówki dusz i dybuka odgrywały istotną rolę nie tylko w tradycji religijnej, ale i w folklorze oraz kulturze popularnej i wysokiej, stając się tematem wielu dzie

  20. Gene for non-insulin-dependent diabetes mellitus (maturity-onset diabetes of the young subtype) is linked to DNA polymorphism on human chromosome 20q

    Energy Technology Data Exchange (ETDEWEB)

    Bell, G.I.; Xiang, Kunsan; Newman, M.V.; Wu, Songhua; Cox, N.J. (Univ. of Chicago, IL (United States)); Wright, L.G.; Spielman, R.S. (Univ. of Pennsylvania, Philadelphia (United States)); Fajans, S.S. (Univ. of Michigan, Ann Arbor (United States))

    1991-02-15

    Maturity-onset diabetes of the young (MODY) is a form of non-insulin-dependent diabetes mellitus characterized by an early age of onset, usually before 25 years of age, and an autosomal dominant mode of inheritance. The largest and best-studies MODY pedigree is the TW family. The majority of the diabetic subjects in this pedigree has a reduced and delayed insulin-secretory response to glucose, and it has been proposed that this abnormal response is the manifestation of the basic genetic defect that leads to diabetes. Using DNA from members of the TW family, the authors tested more than 75 DNA markers for linkage with MODY. A DNA polymorphism in the adenosine deaminase gene (ADA) on the long arm of chromosome 20 was found to cosegregate with MODY. The maximum logarithm of adds (lod score) for linkage between MODY and ADA was 5.25 at a recombination fraction of 0.00. These results indicate that the odds are {gt}178,000:1 that the gene responsible for MODY is this family is tightly linked to the ADA gene on chromosome 20q.

  1. Spanish Young Generation (JJNN) Activities

    Energy Technology Data Exchange (ETDEWEB)

    Millan, Miguel [INITEC Nuclear- Westinghouse, Padilla 17, 28006 Madrid (Spain)

    2008-07-01

    Spanish Young Generation has been very active during 2006-2008. JJNN have mainly focused on communication activities, as conferences at universities, schools and nuclear companies. Lately, becoming in referent of the young politics, journalist and the young people in Nuclear Subjects is the new and most challenging target of the Spanish Young Generation. In order to accomplish with their objects and commitments with their members, JJNN are developing all kinds of activities focused in the young people and the JJNN members. (authors)

  2. Tracking of fatness during childhood, adolescence and young adulthood: a 7-year follow-up study in Madeira Island, Portugal.

    Science.gov (United States)

    Freitas, Duarte; Beunen, Gaston; Maia, José; Claessens, Albrecht; Thomis, Martine; Marques, António; Gouveia, Elvio; Lefevre, Johan

    2012-01-01

    Investigating tracking of fatness from childhood to adolescence, early adolescence to young adulthood and late adolescence to young adulthood. Participants from the Madeira Growth Study were followed during an average period of 7.2 years. Height, body mass, skin-folds and circumferences were measured, nine health- and performance-related tests were administered and the Baecke questionnaire was used to assess physical activity. Skeletal maturity was estimated using the TW3 method. The prevalence of overweight plus obesity ranged from 8.2-20.0% at baseline and from 20.4-40.0% at follow-up, in boys. Corresponding percentages for girls were 10.6-12.0% and 13.2-18.0%. Inter-age correlations for fatness indicators ranged from 0.43-0.77. BMI, waist circumference and sum of skin-folds at 8, 12 and 16-years old were the main predictors of these variables at 15, 19 and 23-years old, respectively. Strength, muscular endurance and aerobic fitness were negatively related to body fatness. Physical activity and maturation were independently associated with adolescent (15 years) and young adult (19 years) fatness. Over 7.2 years, tracking was moderate-to-high for fatness. Variance was explained by fatness indicators and to a small extent by physical fitness, physical activity and maturation.

  3. Young Artists@ CERN

    CERN Multimedia

    2004-01-01

    In view of 50th anniversary of CERN, about 20 young artists will be visiting CERN from 26 to 31 January to learn about the laboratory's research and the mysterious world of particle physics. The impressions they take home will be the main inspiration for the artwork they will then produce for an exhibition to be inaugurated in October 2004 as part of CERN's 50th anniversary celebration. We are looking for scientists who are interested in the Art-Science synergy and who can volunteer to discuss their work at CERN to these young artists during this week (25-31/01). Please contact renilde.vanden.broeck@cern.ch if you are interested. The project is called Young Artists@ CERN and for more information look at this website: http://www.hep.ucl.ac.uk/~andy/CERNart/

  4. Ages of young stars

    CERN Document Server

    Soderblom, David R; Jeffries, Rob D; Mamajek, Eric E; Naylor, Tim

    2013-01-01

    Determining the sequence of events in the formation of stars and planetary systems and their time-scales is essential for understanding those processes, yet establishing ages is fundamentally difficult because we lack direct indicators. In this review we discuss the age challenge for young stars, specifically those less than ~100 Myr old. Most age determination methods that we discuss are primarily applicable to groups of stars but can be used to estimate the age of individual objects. A reliable age scale is established above 20 Myr from measurement of the Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off -- if modest core convection and rotation is included in the models of higher-mass stars. Other available methods for age estimation include the kinematics of young groups, placing stars in Hertzsprung-Russell diagrams, pulsations and seismology, surface gravity measurement, rotation and activ...

  5. Young, Single and Spending

    Institute of Scientific and Technical Information of China (English)

    DAVID HENDRICKSON

    2006-01-01

    @@ As 2006 comes to a close, the Chinese lunar calendar prepares to shift from the Year of the Dog to the Year of the Pig,considered by many to be auspicious years for marriage and childbirth. In accordance with this occasion, hordes of young Chinese have responded with the exchange of wedding vows.

  6. Popular With the Young

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Chopin continues to exert a strong influence upon young piano learners in China Located along the West Third Ring Road of Beijing, the piano school of the Jiang Jie Culture and Arts School, lone of the most popular music schools for children in the city, has never been short

  7. Drugs and Young People

    Science.gov (United States)

    ... fully developed. As a result, the brains of young people may be more susceptible to drug abuse and addiction than adult brains. Abused drugs include Amphetamines Anabolic ... better to prevent drug abuse in the first place. NIH: National Institute on Drug Abuse

  8. Guiding Young Composers

    Science.gov (United States)

    Freund, Don

    2011-01-01

    Composition is learned by discovering that musical ideas can be experienced in a variety of ways, and that new musical ideas can be created by reconfiguring learned materials in new contexts. The act of imagining, defining, and communicating unique musical ideas awakens in young people a dormant part of their brains, unlocking an awareness of the…

  9. A Young Woman Millionaire

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    ZHANG Can is a young woman who likes to laugh. She is also the founder of a business kingdom worth 400 million yuan. Certainly, there were points in her career that were no laughing matter, but now she is general manager of Beijing Dyne Group Corporation. "She’s simply amazing—beyond description," say her friends.

  10. Letters to a Young Writer.

    Science.gov (United States)

    Wright, C. D.; Schulman, Grace

    2001-01-01

    Presents two letters to a young writer, modeled on the influential "Letters to a Young Poet" by Rainer Maria Rilke. Notes the first letter situates itself when a young writer first turns toward poetry; and the second addresses the relationship between mentorship and the imagination, questioning the right of any writer to presume to guide the…

  11. Letters to a Young Writer.

    Science.gov (United States)

    Wright, C. D.; Schulman, Grace

    2001-01-01

    Presents two letters to a young writer, modeled on the influential "Letters to a Young Poet" by Rainer Maria Rilke. Notes the first letter situates itself when a young writer first turns toward poetry; and the second addresses the relationship between mentorship and the imagination, questioning the right of any writer to presume to guide the…

  12. Compact Hermitian Young Projection Operators

    CERN Document Server

    Alcock-Zeilinger, Judith

    2016-01-01

    In this paper, we describe a compact and practical algorithm to construct Hermitian Young projection operators for irreducible representations of the special unitary group SU(N), and discuss why ordinary Young projection operators are unsuitable for physics applications. The proof of this construction algorithm uses the iterative method described by Keppeler and Sj\\"odahl. We further show that Hermitian Young projection operators share desirable properties with Young tableaux, namely a nested hierarchy when "adding a particle". We end by exhibiting the enormous advantage of the Hermitian Young projection operators constructed in this paper over those given by Keppeler and Sj\\"odahl.

  13. Young children's harmonic perception.

    Science.gov (United States)

    Costa-Giomi, Eugenia

    2003-11-01

    Harmony and tonality are two of the most difficult elements for young children to perceive and manipulate and are seldom taught in the schools until the end of early childhood. Children's gradual harmonic and tonal development has been attributed to their cumulative exposure to Western tonal music and their increasing experiential knowledge of its rules and principles. Two questions that are relevant to this problem are: (1) Can focused and systematic teaching accelerate the learning of the harmonic/tonal principles that seem to occur in an implicit way throughout childhood? (2) Are there cognitive constraints that make it difficult for young children to perceive and/or manipulate certain harmonic and tonal principles? A series of studies specifically addressed the first question and suggested some possible answers to the second one. Results showed that harmonic instruction has limited effects on children's perception of harmony and indicated that the drastic improvement in the perception of implied harmony noted approximately at age 9 is due to development rather than instruction. I propose that young children's difficulty in perceiving implied harmony stems from their attention behaviors. Older children have less memory constraints and more strategies to direct their attention to the relevant cues of the stimulus. Younger children focus their attention on the melody, if present in the stimulus, and specifically on its concrete elements such as rhythm, pitch, and contour rather than its abstract elements such as harmony and key. The inference of the abstract harmonic organization of a melody required in the perception of implied harmony is thus an elusive task for the young child.

  14. NEW MEMBERS OF THE SCORPIUS-CENTAURUS COMPLEX AND AGES OF ITS SUB-REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Song, Inseok [Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602-2451 (United States); Zuckerman, B. [Department of Physics and Astronomy, University of California, Los Angeles, 475 Portola Plaza, Los Angeles, CA 90095-1547 (United States); Bessell, M. S. [Research School of Astronomy and Astrophysics, Institute of Advanced Studies, The Australian National University, ACT 2611 (Australia)

    2012-07-15

    We have spectroscopically identified {approx}100 G-, K-, and M-type members of the Scorpius-Centaurus complex. To deduce the age of these young stars we compare their Li {lambda}6708 absorption line strengths against those of stars in the TW Hydrae association and {beta} Pictoris moving group. These line strengths indicate that Sco-Cen stars are younger than {beta} Pic stars whose ages of {approx}12 Myr have previously been derived from a kinematic traceback analysis. Our derived age, {approx}10 Myr, for stars in the Lower Centaurus Crux and Upper Centaurus Lupus subgroups of ScoCen is younger than previously published ages based on the moving cluster method and upper main-sequence fitting. The discrepant ages are likely due to an incorrect (or lack of) cross-calibration between model-dependent and model-independent age-dating methods.

  15. Prison and young convicts

    Directory of Open Access Journals (Sweden)

    Krzysztof Linowski

    2013-06-01

    Full Text Available Penalty, including imprisonment comprises one of the basic forms of reaction to crime. It differs from other possible penalties in the degree of discomfort and in the legal consequences. There are also different goals in case of criminal penalty as a legal and social consequence of a crime or misconduct. Imprisonment aims at taking different actions which consequently, should lead to the situation where the criminal does not return to committing crimes. It is so called penitentiary rehabilitation which is a multidimensional phenomenon and it should be considered from the modern society point of view. Its range includes correction of inadequate individual’s behavior and his or her adaptation of norms and values shared by the general public, as well as taking and being persistent in the process of designing oneself, own personality and consistent implementation of the self- vision in the future, organized hierarchically for the given time periods. Therefore, different means and action are taken under the implementation of imprisonment. Moreover, convicted prisoners are divided into different groups in penitentiaries. One of the groups is the group of young convicts. The goal of this article is to examine and describe the opinion of the young convicts on the penitentiary as a penal and rehabilitation institution. To perform the study, sixty young convicts were selected. In the test method, the diagnostic survey was applied. The original authoring questionnaire was used in the study. The study was performed in the Penitentiary in Radom, in December 2012.

  16. CONFERENCE OF YOUNG SCIENTISTS

    Directory of Open Access Journals (Sweden)

    article editorial

    2008-01-01

    Full Text Available A conference of young scientists dedicated to the 245th anniversary of the Scientific Center of Children's Health was held on September 12, 2008.Speakers at the conference were young professionals working at SCCH of RAMS, Sechenov Moscow Medical Academy, Institute of Pediatric Hematology, Oncology, and Immunology. During the conference the poster session was held in which young scientists of the Centre took part. Presentations of participants were evaluated by the members of the Academic Council of SCCH, leading specialists of the Center. Gifts to the winners of the conference were provided by "Procter & Gamble".Winners and awardees:I place: Chistyakova V.P. - Clinical intern at SCCH of RAMS;II place: Gudkova E.Yu. - Researcher at the Department of Rheumatology of SCCH of RAMS;III place: Darmanyan A.S. - Researcher at the Department of diagnostics and rehabilitation treatment of SCCH of RAMS.Best poster paper: Plyakin V.A. - Researcher at Surgical Department NTSZD RAMS.Audience Award: Tikhomirova E.A. - Researcher at the Department of functional diagnostics of SCCH of RAMS.

  17. Young Journalists in Vojvodina

    Directory of Open Access Journals (Sweden)

    Smiljana Milinkov

    2010-12-01

    Full Text Available According to a recent study entitled, ”Professional Status of Young Journalists in the Autonomous Province of Vojvodina”, the primary complaints of journalists thirty-years old and younger are overtime,small salaries, uneducated executives, censorship, and the infl uence of politics and advertisers on editorial policy. Most of the interviewees are not permanently employed, receiving some 200€ honoraria,and as they have mentioned, executives and editors do not suffi ciently trust them, nor are they aff orded adequate space to express themselves. While Serbia has enacted nominal steps toward democracy over the past ten years, and in the process has reduced the number of persecutions and arrests of journalists and punishments and cancellations of media, more than half of the young journalists surveyed have experienced restraints in freedom of speech while doing their job. Further, ten percent of those surveyed state that they are often censored. The basis of this examination emanates from research on the professional status of ”eternal freelancers”, conducted in 2009 by the Youth Development Fund (Razvojni fond za mlade – RFM expert team, with the support from the Provincial Secretariat for Sport and Youth. In addition, a questionnaire has been filled out by over 50 young journalists from Vojvodina.

  18. Understanding Gas-Phase Ammonia Chemistry in Protoplanetary Disks

    Science.gov (United States)

    Chambers, Lauren; Oberg, Karin I.; Cleeves, Lauren Ilsedore

    2017-01-01

    Protoplanetary disks are dynamic regions of gas and dust around young stars, the remnants of star formation, that evolve and coagulate over millions of years in order to ultimately form planets. The chemical composition of protoplanetary disks is affected by both the chemical and physical conditions in which they develop, including the initial molecular abundances in the birth cloud, the spectrum and intensity of radiation from the host star and nearby systems, and mixing and turbulence within the disk. A more complete understanding of the chemical evolution of disks enables a more complete understanding of the chemical composition of planets that may form within them, and of their capability to support life. One element known to be essential for life on Earth is nitrogen, which often is present in the form of ammonia (NH3). Recent observations by Salinas et al. (2016) reveal a theoretical discrepancy in the gas-phase and ice-phase ammonia abundances in protoplanetary disks; while observations of comets and protostars estimate the ice-phase NH3/H2O ratio in disks to be 5%, Salinas reports a gas-phase NH3/H2O ratio of ~7-84% in the disk surrounding TW Hydra, a young nearby star. Through computational chemical modeling of the TW Hydra disk using a reaction network of over 5000 chemical reactions, I am investigating the possible sources of excess gas-phase NH3 by determining the primary reaction pathways of NH3 production; the downstream chemical effects of ionization by ultraviolet photons, X-rays, and cosmic rays; and the effects of altering the initial abundances of key molecules such as N and N2. Beyond providing a theoretical explanation for the NH3 ice/gas discrepancy, this new model may lead to fuller understanding of the gas-phase formation processes of all nitrogen hydrides (NHx), and thus fuller understanding of the nitrogen-bearing molecules that are fundamental for life as we know it.

  19. A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood

    CERN Document Server

    Bell, Cameron P M; Naylor, Tim

    2015-01-01

    We present a self-consistent, absolute isochronal age scale for young (< 200 Myr), nearby (< 100 pc) moving groups in the solar neighbourhood based on homogeneous fitting of semi-empirical pre-main-sequence model isochrones using the tau^2 maximum-likelihood fitting statistic of Naylor & Jeffries in the M_V, V-J colour-magnitude diagram. The final adopted ages for the groups are: 149+51-19 Myr for the AB Dor moving group, 24+/-3 Myr for the {\\beta} Pic moving group (BPMG), 45+11-7 Myr for the Carina association, 42+6-4 Myr for the Columba association, 11+/-3 Myr for the {\\eta} Cha cluster, 45+/-4 Myr for the Tucana-Horologium moving group (Tuc-Hor), 10+/-3 Myr for the TW Hya association, and 22+4-3 Myr for the 32 Ori group. At this stage we are uncomfortable assigning a final, unambiguous age to the Argus association as our membership list for the association appears to suffer from a high level of contamination, and therefore it remains unclear whether these stars represent a single population of co...

  20. Herschel observations of the hydroxyl radical (OH) in young stellar objects

    CERN Document Server

    Wampfler, S F; Bruderer, S; Benz, A O; van Dishoeck, E F; Kristensen, L E; Visser, R; Doty, S D; Melchior, M; van Kempen, T A; Yildiz, U A; Dedes, C; Goicoechea, J R; Baudry, A; Melnick, G; Bachiller, R; Benedettini, M; Bergin, E; Bjerkeli, P; Blake, G A; Bontemps, S; Braine, J; Caselli, P; Cernicharo, J; Codella, C; Daniel, F; di Giorgio, A M; Dominik, C; Encrenaz, P; Fich, M; Fuente, A; Giannini, T; de Graauw, Th; Helmich, F; Herpin, F; Jacq, T; Johnstone, D; ørgensen, J K J; Larsson, B; Lis, D; Liseau, R; Marseille, M; McCoey, C; Neufeld, D; Nisini, B; Olberg, M; Parise, B; Pearson, J C; Plume, R; Risacher, C; Santiago-Garcia, J; Saraceno, P; Shipman, R; Tafalla, M; van der Tak, F F S; Wyrowski, F; Roelfsema, P; Jellema, W; Dieleman, P; Caux, E; Stutzki, J

    2010-01-01

    Water in Star-forming regions with Herschel (WISH) is a Herschel Key Program investigating the water chemistry in young stellar objects (YSOs) during protostellar evolution. Hydroxyl (OH) is one of the reactants in the chemical network most closely linked to the formation and destruction of H2O. High-temperature chemistry connects OH and H2O through the OH + H2 H2O + H reactions. Formation of H2O from OH is efficient in the high-temperature regime found in shocks and the innermost part of protostellar envelopes. Moreover, in the presence of UV photons, OH can be produced from the photo-dissociation of H2O. High-resolution spectroscopy of the OH 163.12 micron triplet towards HH 46 and NGC 1333 IRAS 2A was carried out with the Heterodyne Instrument for the Far Infrared (HIFI) on board Herschel. The low- and intermediate-mass YSOs HH 46, TMR 1, IRAS 15398-3359, DK Cha, NGC 7129 FIRS 2, and NGC 1333 IRAS 2A were observed with the Photodetector Array Camera and Spectrometer (PACS) in four transitions of OH and tw...

  1. PAs: Fifty years young.

    Science.gov (United States)

    Mandel, Ellen D; North, Shannon

    2017-10-01

    The PA profession is 50 years young. Practicing PAs and current students hail from several generational categories ranging from Builders to Generation Z. This article reviews how different generations may have experienced PA program expansion, professional identity, state licensing, and prescription delegation. The authors sampled a cohort of PA program applicants about their views on what evokes optimism and concern for the PA profession. These themes mirror the recently paved professional road, while posing the all-important question: What construction lies on the horizon?

  2. The Qingdao Young Reporters School

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Arank of young journalists is active in Qingdao, Shandong Province. In 1993, at a conference during the 11th Qingdao Municipal People’s Congress, people saw children, carrying cameras easily and confidently and taking photos for provincial-and city-level leaders seated at the rostrum. They were young journalists from the Qingdao Young Reporter’s School, so they can be said to be professionally trained.

  3. Sexing young snowy owls

    Science.gov (United States)

    Seidensticker, M.T.; Holt, D.W.; Detienne, J.; Talbot, S.; Gray, K.

    2011-01-01

    We predicted sex of 140 Snowy Owl (Bubo scandiacus) nestlings out of 34 nests at our Barrow, Alaska, study area to develop a technique for sexing these owls in the field. We primarily sexed young, flightless owls (3844 d old) by quantifying plumage markings on the remiges and tail, predicting sex, and collecting blood samples to test our field predictions using molecular sexing techniques. We categorized and quantified three different plumage markings: two types of bars (defined as markings that touch the rachis) and spots (defined as markings that do not touch the rachis). We predicted sex in the field assuming that males had more spots than bars and females more bars than spots on the remiges and rectrices. Molecular data indicated that we correctly sexed 100% of the nestlings. We modeled the data using random forests and classification trees. Both models indicated that the number and type of markings on the secondary feathers were the most important in classifying nestling sex. The statistical models verified our initial qualitative prediction that males have more spots than bars and females more bars than spots on flight feathers P6P10 for both wings and tail feathers T1 and T2. This study provides researchers with an easily replicable and highly accurate method for sexing young Snowy Owls in the field, which should aid further studies of sex-ratios and sex-related variation in behavior and growth of this circumpolar owl species. ?? 2011 The Raptor Research Foundation, Inc.

  4. The young female athlete.

    Science.gov (United States)

    Hurvitz, Michal; Weiss, Ram

    2009-12-01

    Participation of adolescents and young women in strenuous sports activity may lead to various metabolic and psychological derangements of clinical relevance to the endocrinologist. The most common manifestations encountered in practice are primary and secondary amenorrhea, reduced bone mineral density and eating disorders. The occurrence of all three together has been named "the athletic triad". The underlying hormonal drivers that lead to some of these manifestations are the reduced leptin level as well as the persistent low grade stress response commonly observed in such females. "Exercise-related female reproductive dysfunction" (ERFRD), can possibly include short-term (infertility) and long-term (osteoporosis) consequences. Functional hypothalamic amenorrhea, a manifestation of ERFRD in adolescence, is an integrated response to the combination of excessive physical and emotional stress, exercise, and/or reduced food intake characterized by decreased endogenous GNRH secretion. The primary aim of treating these athletes should be the prevention of the development of any component of the triad as well as the whole complex by educating athletes, trainers, parents and health care professionals about proper nutrition and safe training. The long term prognosis is good. However, significant long term morbidity may affect these young women later in life.

  5. A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood

    Science.gov (United States)

    Bell, Cameron P. M.; Mamajek, Eric E.; Naylor, Tim

    2015-11-01

    We present a self-consistent, absolute isochronal age scale for young ( ≲ 200 Myr), nearby ( ≲ 100 pc) moving groups in the solar neighbourhood based on homogeneous fitting of semi-empirical pre-main-sequence model isochrones using the τ2 maximum-likelihood fitting statistic of Naylor & Jeffries in the MV, V - J colour-magnitude diagram. The final adopted ages for the groups are as follows: 149^{+51}_{-19} {Myr} for the AB Dor moving group, 24 ± 3 Myr for the β Pic moving group (BPMG), 45^{+11}_{-7} {Myr} for the Carina association, 42^{+6}_{-4} {Myr} for the Columba association, 11 ± 3 Myr for the η Cha cluster, 45 ± 4 Myr for the Tucana-Horologium moving group (Tuc-Hor), 10 ± 3 Myr for the TW Hya association and 22^{+4}_{-3} {Myr} for the 32 Ori group. At this stage we are uncomfortable assigning a final, unambiguous age to the Argus association as our membership list for the association appears to suffer from a high level of contamination, and therefore it remains unclear whether these stars represent a single population of coeval stars. Our isochronal ages for both the BPMG and Tuc-Hor are consistent with recent lithium depletion boundary (LDB) ages, which unlike isochronal ages, are relatively insensitive to the choice of low-mass evolutionary models. This consistency between the isochronal and LDB ages instils confidence that our self-consistent, absolute age scale for young, nearby moving groups is robust, and hence we suggest that these ages be adopted for future studies of these groups. Software implementing the methods described in this study is available from http://www.astro.ex.ac.uk/people/timn/tau-squared/.

  6. Injuries to the Young Athlete.

    Science.gov (United States)

    Sandusky, Jane C.

    A review of literature on the incidence and nature of injuries to young athletes is presented on the topics of: (1) physiological characteristics of preadolescents, adolescents, and young adults; (2) musculo-skeletal changes in the growing athlete; (3) epiphyseal injuries and their potential for resulting in temporary or permanent impairment; (4)…

  7. Effective Communication with Young People

    Science.gov (United States)

    Shanahan, Patrick; Elliott, David

    2009-01-01

    The Australian Government established the Office for Youth (the Office) in September 2008 in an effort to engage with the young people of Australia. The Office will work with other government agencies to help young people reach their full potential; make effective transitions to adulthood as they continue to learn, start work, make decisions that…

  8. Young people and sexual orientation

    NARCIS (Netherlands)

    Lisette Kuyper

    2015-01-01

    Original title: Young people and sexual orientation The Netherlands Institute for Social Research ¦ SCP carries out regular research on lesbian, gay, bisexual and transgender (LGBT) individuals. In this report, the focus is on young people in the Netherlands. The report addresses two issues: attitud

  9. Young women's use of medicines

    DEFF Research Database (Denmark)

    Hansen, Dana Lee; Hansen, Ebba Holme; Holstein, Bjørn Evald

    2009-01-01

    Medicine use among youths is widespread and on the increase. This is especially true for young females, whose utilization of a variety of medications grows considerably during the teenage years. This user perspective study aims to obtain a greater understanding of what young women perceive as the...

  10. Young Peoples' Ideas of Infinity.

    Science.gov (United States)

    Monaghan, John

    2001-01-01

    Considers young peoples' views of infinity prior to instruction in the methods mathematicians use in addressing the subject of infinity. Presents a partially historical account of studies examining young peoples' ideas of infinity. Four sections address potential pitfalls for research in this area and the work of Piaget, issues concerning the…

  11. Young people and sexual orientation

    NARCIS (Netherlands)

    Lisette Kuyper

    2015-01-01

    Original title: Young people and sexual orientation The Netherlands Institute for Social Research ¦ SCP carries out regular research on lesbian, gay, bisexual and transgender (LGBT) individuals. In this report, the focus is on young people in the Netherlands. The report addresses two issues:

  12. Young People and Contemporary Art

    Science.gov (United States)

    Illeris, Helene

    2005-01-01

    In this article empirical examples are used to connect theories about young people, contemporary art forms and learning. The first part of the article introduces the new forms of consciousness which, according to the youth researchers Birgitte Simonsen and Thomas Ziehe, characterize young people of today. In the second part, the qualities of…

  13. Osteosarcoma in young children.

    Science.gov (United States)

    Kozakewich, H; Perez-Atayde, A R; Goorin, A M; Wilkinson, R H; Gebhardt, M C; Vawter, G F

    1991-02-01

    The clinicopathologic features of osteosarcoma in 12 children younger than 16 years of age treated at The Children's Hospital and Dana-Farber Cancer Institute, Boston, during a 70-year time period are presented. Only one of six children treated before 1972 is a long-term survivor. Four of six children (67%) treated after 1972 are disease-free with an average follow-up of 8.8 years. The year 1972 marked the onset of use of effective chemotherapy in osteosarcoma, namely, high-dose methotrexate and leucovorin rescue. It would appear that the pathologic features and behavior of osteosarcoma in young children is similar to that of osteosarcoma in older children and adolescents. A combination of complete (wide) surgical resection or amputation and aggressive chemotherapy offers the best chance of long-term survival.

  14. Media life of the young

    DEFF Research Database (Denmark)

    Westlund, Oscar; Bjur, Jakob

    2014-01-01

    This is a thorough investigation into contemporary young people and their media life. The article conceptualizes a typology of media life, drawing on a theoretical body involving the sociology of generations, life course research, media life and individualization. This empirically derived typology...... makes a strong instrument for an understanding of the media life of the young, furnishing insights into how they have constructed their use of media. The investigation is based on a robust national survey with Swedes born 1994–2001, conducted in 2010, and focusing on four media: television, gaming......, the Internet and mobile devices. Two of the findings are particularly surprising. Firstly, the results reveal that the young generally lead heterogeneous media lives, varying with age and sex. Secondly, although some young people literarily live their life in media, there are also de facto young who live...

  15. Irreducible Specht modules are signed Young modules

    OpenAIRE

    Hemmer, David J.

    2005-01-01

    Recently Donkin defined signed Young modules as a simultaneous generalization of Young and twisted Young modules for the symmetric group. We show that in odd characteristic, if a Specht module $S^\\lambda$ is irreducible, then $S^\\lambda$ is a signed Young module. Thus the set of irreducible Specht modules coincides with the set of irreducible signed Young modules. This provides evidence for our conjecture that the signed Young modules are precisely the class of indecomposable self-dual module...

  16. Characteristics of Young Learners and Implications for Teaching Young Learners

    Institute of Scientific and Technical Information of China (English)

    陈佳燕

    2016-01-01

    Teaching young learners is much more difficult for teachers because learners at this age have their own characteristics and needs and are difficult to manage.For example,they are more easily distracted,they may suffer from more peer pressure and they have less knowledge about the world,which results in their great curiosity about this world and anything new.In order to get along well with young learners and teach them effectively,it is necessary to explore these characteristics and draw implications from them.Therefore,this paper intends to explore the three most important factors which make teaching young learners different from teaching adults and gives suggestion to the teacher of young learners.

  17. The Young and the Stressed

    DEFF Research Database (Denmark)

    Leppink, Eric W.; Odlaug, Brian L.; Lust, Katherine

    2016-01-01

    among college students, are limited. This study examined potential associations between perceived stress, academic achievement, physical/mental health, and impulse control disorders in young adults. A total of 1805 students completed an online survey and were included in the analysis. Responders were...... stress and numerous aspects of mental/physical health in young adults, which could be an important consideration for individuals working with college students.......High levels of stress are common among young adults, particularly those enrolled in college. These degrees of stress have shown numerous deleterious effects across both academic and health variables. Findings regarding the role of stress in the presentation of impulse control disorders, particular...

  18. YOUNG ATHLETES' MOTIVATIONAL PROFILES

    Directory of Open Access Journals (Sweden)

    Juan Antonio Moreno Murcia

    2007-06-01

    Full Text Available The aim of this study was to examine the relationship between motivational characteristics and dispositional flow. In order to accomplish this goal, motivational profiles emerging from key constructs within Achievement Goal Theory and Self-Determination Theory were related to the dispositional flow measures. A sample of 413 young athletes (Age range 12 to 16 years completed the PMCSQ-2, POSQ, SMS and DFS measures. Cluster analysis results revealed three profiles: a "self-determined profile" characterised by higher scores on the task-involving climate perception and on the task orientation; a "non-self-determined profile", characterised by higher scores on ego-involving climate perception and ego orientation; and a "low self-determined and low non-self-determined profile" which had the lowest dispositional flow. No meaningful differences were found between the "self-determined profile" and the "non-self-determined profile" in dispositional flow. The "self-determined profile" was more commonly associated with females, athletes practising individual sports and those training more than three days a week. The "non-self-determined profile" was more customary of males and athletes practising team sports as well as those training just two or three days a week

  19. [Young children and books].

    Science.gov (United States)

    Diatkine, R; Bonnafé, M; Roy, J; Camus, C; Brandao, C

    1986-01-01

    Children come into contact very early with the written language. The work of Emilia Ferreiro, a student of Piaget, has shown that from early on, well before they can read, they know that the written word has a meaning. Their successive hypotheses show an elaboration which does not occur by chance. Experience shows that babies have a specific interest for a book as an object. They recognize the value of the pictures, as much representations of their mental representations as are words, whereas these two capacities evolve in a complementary fashion. The capacity to be interested by a narrative introduces a new form of organization in the chain of representations, whether they refer to absent or imaginary objects. A good story has a special place among the narratives the child hears, which actually have the specific structures of the written language. The authors of this work report a number of examples of very young children who are put in contact with books. They see in this a new model for mental health work which can be set up by virtue of meetings outside the school rooms, the mental health services, and even of the libraries, by people of different professional skills, in order to loosen the vice of the children's daily routine, and to give the child time to dream with the books, and to draw the adults in to a salutary disorder.

  20. Development of the Young Brain

    Medline Plus

    Full Text Available ... Traumatic Events (3 items) Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For ... Health neuroscientist Dr. Jay Giedd has studied the development of the adolescent brain. Decades of imaging work ...

  1. Development of the Young Brain

    Medline Plus

    Full Text Available ... Traumatic Events (3 items) Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For ... Early evidence suggests -pretty well. In fact, the human brain has a track record of successfully adapting ...

  2. Development of the Young Brain

    Medline Plus

    Full Text Available ... 3 items) Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For more than ... Adolescents Brain Anatomy and Physiology Institute Announcements Contact the Press Office 301-443-4536 NIMHpress@nih.gov ...

  3. Development of the Young Brain

    Medline Plus

    Full Text Available ... Traumatic Events (3 items) Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For ... Health neuroscientist Dr. Jay Giedd has studied the development of the adolescent brain. Decades of imaging work ...

  4. The nearest young moving groups

    CERN Document Server

    López-Santiago, J; Fernández-Figueroa, M J; Montes, D

    2006-01-01

    The latest results in the research of forming planetary systems have led several authors to compile a sample of candidates for searching for planets in the vicinity of the sun. Young stellar associations are indeed excellent laboratories for this study, but some of them are not close enough to allow the detection of planets through adaptive optics techniques. However, the existence of very close young moving groups can solve this problem. Here we have compiled the members of the nearest young moving groups, as well as a list of new candidates from our catalogue of late-type stars possible members of young stellar kinematic groups, studying their membership through spectroscopic and photometric criteria.

  5. Informal Education with Young Offenders.

    Science.gov (United States)

    Williams, David

    1994-01-01

    The example of an environmental conservation program for young offenders demonstrates the efficacy of group activities in enhancing self-esteem and coping skills and in enabling transition out of the custodial environment. (SK)

  6. Development of the Young Brain

    Medline Plus

    Full Text Available ... Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For more than twenty years, ... Giedd has studied the development of the adolescent brain. Decades of imaging work have led to remarkable ...

  7. Development of the Young Brain

    Medline Plus

    Full Text Available ... Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For more than twenty years, ... Giedd has studied the development of the adolescent brain. Decades of imaging work have led to remarkable ...

  8. Development of the Young Brain

    Medline Plus

    Full Text Available ... 3 items) Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For more than ... Adolescents Brain Anatomy and Physiology Institute Announcements Contact the Press Office 301-443-4536 NIMHpress@nih.gov ...

  9. Breast Cancer in Young Women

    Science.gov (United States)

    ... NPCR 2017 CDC National Cancer Conference Stay Informed Breast Cancer in Young Women Recommend on Facebook Tweet Share Compartir Syndicate this page Marleah's family history of breast cancer was her motivation for pursuing a career where ...

  10. Young People with a Twist

    DEFF Research Database (Denmark)

    Sørensen, Bo Wagner; Madsen, Diana Højlund

    The report is based on group interviews with 33 young people with ethnic minority backgrounds. They have been asked about their educational and vocational wishes and also touch on a number of issues such as family, gender equality, discrimination and integration.......The report is based on group interviews with 33 young people with ethnic minority backgrounds. They have been asked about their educational and vocational wishes and also touch on a number of issues such as family, gender equality, discrimination and integration....

  11. Nutrition for young soccer players

    OpenAIRE

    Umaña Alvarado, Mónica

    2005-01-01

    El artículo también se encuentra escrito en español. The growing participation of young people in soccer is a motivation so that the trainers, physical educators and parents know which are the special requirements to practice this sport in a safe manner, specially the nutritional requirements. The present revision includes generalities on the physiological demands of soccer, the differences between young people and adults when making prolonged exercise, the necessities ...

  12. Young Instrumentalists’ Music Literacy Acquisition

    OpenAIRE

    Blix, Hilde Synnøve

    2015-01-01

    ABSTRACT The aim of this article is to present and discuss the findings of a research project concerning music literacy acquisition among young beginners on music instruments. The reported project examines the learning strategies that young students use in order to make sense of notated music in the first year of training. Theories from the research field of language learning are applied to illuminate music literacy as a learning process. Observations and interviews were used to collect da...

  13. Myocardial infarction in young adults

    OpenAIRE

    Egred, M; Viswanathan, G; Davis, G.

    2005-01-01

    Although myocardial infarction (MI) mainly occurs in patients older than 45, young men or women can suffer MI. Fortunately, its incidence is not common in patients younger than 45 years. However, the disease carries a significant morbidity, psychological effects, and financial constraints for the person and the family when it occurs at a young age. The causes of MI among patients aged less than 45 can be divided into four groups: (1) atheromatous coronary artery disease; (2) non-atheromatous ...

  14. The apo riboswitch as a molecular hydra.

    Science.gov (United States)

    Wedekind, Joseph E

    2010-07-14

    Riboswitches "sense" metabolites but knowledge is sparse for structures without bound ligand. Stoddard et al. (2010) determined an apo riboswitch structure "closed" to metabolite binding. Further SAXS, biochemical, and computational analyses support ensemble behavior with interconverting open and closed conformations.

  15. The Apo Riboswitch as a Molecular Hydra

    OpenAIRE

    Wedekind, Joseph E.

    2010-01-01

    Riboswitches ‘sense’ metabolites but knowledge is sparse for structures without bound ligand. Stoddard et al. (2010) determined an apo riboswitch structure ‘closed’ to metabolite binding. Further SAXS, biochemical and computational analyses support ensemble behavior with interconverting open and closed conformations.

  16. Intercellular junctions in nerve-free hydra

    DEFF Research Database (Denmark)

    McDowall, A W; Grimmelikhuijzen, C J

    1980-01-01

    with particles in an "enplaque conformation appearing as a raised plateau on the E-face or as a depression on the P-face; (ii) structures morphologically similar to gap junctions in rat liver, containing particles on the P-face and corresponding pits on the E-face, both having hexagonal packing with a lattice...

  17. Far-Ultraviolet H2 Emission from Circumstellar Disks

    CERN Document Server

    Ingleby, Laura; Bergin, Edwin; Yerasi, Ashwin; Espaillat, Catherine; Herczeg, Gregory; Roueff, Evelyne; Abgrall, Herve; Hernandez, Jesus; Briceno, Cesar; Pascucci, Ilaria; Miller, Jon; Fogel, Jeffrey; Hartmann, Lee; Meyer, Michael; Carpenter, John; Crockett, Nathan; McClure, Melissa

    2009-01-01

    We analyze the far-ultraviolet (FUV) spectra of 33 classical T Tauri stars (CTTS), including 20 new spectra obtained with the Advanced Camera for Surveys Solar Blind Channel (ACS/SBC) on the Hubble Space Telescope. Of the sources, 28 are in the ~1 Myr old Taurus-Auriga complex or Orion Molecular Cloud, 4 in the 8-10 Myr old Orion OB1a complex and one, TW Hya, in the 10 Myr old TW Hydrae Association. We also obtained FUV ACS/SBC spectra of 10 non-accreting sources surrounded by debris disks with ages between 10 and 125 Myr. We use a feature in the FUV spectra due mostly to electron impact excitation of \\h2 to study the evolution of the gas in the inner disk. We find that the \\h2 feature is absent in non-accreting sources, but is detected in the spectra of CTTS and correlates with accretion luminosity. Since all young stars have active chromospheres which produce strong X-ray and UV emission capable of exciting \\h2 in the disk, the fact that the non-accreting sources show no \\h2 emission implies that the \\h2 ga...

  18. [GASTRIC CANCER IN YOUNG PATIENTS

    Science.gov (United States)

    Quispe, Dolly; Ruiz, Eloy; Celis, Juan; Berrospi, Francisco; Payet, Eduardo

    2000-01-01

    OBJECTIVE: In order to determine a the clinicopatological features in young patients with gastric cancer and compare them with aged patients.PATIENTS AND METHODS: For this study, we selected the clinical charts from the total of patients with histological proved diagnosis of gastric adenocarcinoma admitted at the INEN between 1980 and 1996 whose age was less than 31 year (Young group, n =92). As a comparison group (Average Group) we chose of the same universe, a random sample of 184 patients between 50 to 70 years of age. Epidemiological, clinical and histological features, operability and resecability, TNM stage, type of surgery and follow-up of both groups were analyzed.RESULTS: In the Young Group in compared with Average Group, females were more frequent (73.9% vs. 50.5% p0.001). The mean survival time in the Young Group was 74.9 months and in the Average Group was 36.03 months (p=0.26), there were no significant differences in the survival between resecability and sex (p=0.10 and p=0.41).CONCLUSION: The females and undifferentiated carcinoma was the most frequent features in the young patients with gastric cancer. The survival in this group is better than the average group but this was a no significant difference because the diagnosis was made in late stages.

  19. Young Exoplanet Transit Initiative (YETI)

    CERN Document Server

    Neuhäuser, R; Berndt, A; Maciejewski, G; Takahashi, H; Chen, W P; Dimitrov, D P; Pribulla, T; Nikogossian, E H; Jensen, E L N; Marschall, L; Wu, Z -Y; Kellerer, A; Walter, F M; Briceño, C; Chini, R; Fernandez, M; Raetz, St; Torres, G; Latham, D W; Quinn, S N; Niedzielski, A; Bukowiecki, Ł; Nowak, G; Tomov, T; Tachihara, K; Hu, S C -L; Hung, L W; Radeva, D P Kjurkchieva \\and V S; Mihov, B M; Slavcheva-Mihova, L; Bozhinova, I N; Budaj, J; Vaňko, M; Kundra, E; Hambálek, Ľ; Krushevska, V; Movsessian, T; Harutyunyan, H; Downes, J J; Hernandez, J; Hoffmeister, V H; Cohen, D H; Abel, I; Ahmad, R; Chapman, S; Eckert, S; Goodman, J; Guerard, A; Kim, H M; Koontharana, A; Sokol, J; Trinh, J; Wang, Y; Zhou, X; Redmer, R; Kramm, U; Nettelmann, N; Mugrauer, M; Schmidt, J; Moualla, M; Ginski, C; Marka, C; Adam, C; Seeliger, M; Baar, S; Roell, T; Schmidt, T O B; Trepl, L; Eisenbei\\ss, T; Fiedler, S; Tetzlaff, N; Schmidt, E; Hohle, M M; Kitze, M; Chakrova, N; Gräfe, C; Schreyer, K; Hambaryan, V V; Broeg, C H; Koppenhoefer, J; Pandey, A K

    2011-01-01

    We present the Young Exoplanet Transit Initiative (YETI), in which we use several 0.2 to 2.6m telescopes around the world to monitor continuously young (< 100 Myr), nearby (< 1 kpc) stellar clusters mainly to detect young transiting planets (and to study other variability phenomena on time-scales from minutes to years). The telescope network enables us to observe the targets continuously for several days in order not to miss any transit. The runs are typically one to two weeks long, about three runs per year per cluster in two or three subsequent years for about ten clusters. There are thousands of stars detectable in each field with several hundred known cluster members, e.g. in the first cluster observed, Tr-37, a typical cluster for the YETI survey, there are at least 469 known young stars detected in YETI data down to R=16.5 mag with sufficient precision of 50 milli-mag rms (5 mmag rms down to R=14.5 mag) to detect transits, so that we can expect at least about one young transiting object in this cl...

  20. Collisions in young triple systems

    CERN Document Server

    Rawiraswattana, Krisada; Goodwin, Simon P

    2011-01-01

    We perform N-body simulations of young triple systems consisting of two low-mass companions orbiting around a significantly more massive primary. We find that, when the orbits of the companions are coplanar and not too widely separated, the chance of a collision between the two companions can be as high as 20 per cent. Collisions between one of the companions (always the less massive) and the primary can also occur in systems with unequal-mass companions. The chance of collisions is a few per cent in systems with more realistic initial conditions, such as with slightly non-coplanar orbits and unequal-mass companions. If the companions start widely separated then collision are very rare except in some cases when the total mass of the companions is large. We suggest that collisions between members of young multiple systems may explain some unusual young multiple systems such as apparently non-coeval companions.

  1. Multicultural Monologues for Young Actors. The Young Actors Series.

    Science.gov (United States)

    Slaight, Craig, Ed.; Sharrar, Jack, Ed.

    This book presents 62 monologue selections from diverse cultures for young actors to perform. The book's selections offer "quality literature by significant writers." Some of the writers represented in the book are George C. Wolfe, Miguel Pinero, Lorraine Hansberry, Amiri Baraka (LeRoi Jones), John M. Synge, Yukio Mishima, Reynolds…

  2. Young Scientist in Classroom

    Science.gov (United States)

    Doran, Rosa

    simulate experiments, in order to spark young people’s interest in science and in following scientific careers.

  3. Efeito do intervalo de recuperação entre séries de extensões isocinéticas de joelho em homens jovens destreinados Effect of recovery interval between sets of isokinetic knee extensions among untrained young men

    Directory of Open Access Journals (Sweden)

    R Celes

    2009-08-01

    Full Text Available OBJETIVO: Avaliar o efeito de dois diferentes Intervalos de Recuperação (IR entre séries de extensões isocinéticas de joelho no Pico de Torque (PT e no Trabalho Total (TT em jovens destreinados. MÉTODOS: Dezoito homens (24,22±2,58 anos; 80,42±11,41 kg realizaram três séries de 10 extensões isocinéticas com o joelho direito a 60° e 180°/s. O IR entre as séries foram de 1 e 2 minutos, contrabalanceados entre os dois dias de teste, separados por, no mínimo, 48 horas. A taxa de trabalho-recuperação foi de 1:3 e 1:6 para 60°/s e 1:6 e 1:12 para 180°/s. Os voluntários não participavam de programas de treinamento resistido há pelo menos 6 meses. A análise estatística foi a ANOVA de medidas repetidas 2 x 3 [IR (1 e 2 minutos x série (1ª, 2ª e 3ª]. O nível de significância foi aOBJECTIVE: To assess the effect of two recovery intervals (RIs between sets of isokinetic knee extension exercises on peak torque (PT and total work (TW, among untrained young men. METHODS: Eighteen men (24.22±2.58 years; 80.42±11.41 kg performed three sets of ten isokinetic extensions of the right knee, at 60° and 180°/s. The RIs between the sets were one and two minutes long, spread over two test days separated by a minimum of 48 hours. The work-to-recovery ratio was 1:3 and 1:6 for 60°/s, and 1:6 and 1:12 for 180°/s. The subjects had not participated in any resistance training programs within the last six months. The statistical analysis consisted of 2 x 3 repeated-measures ANOVA [RI (one or two minutes x set (1st, 2nd or 3rd]. The significance level was a<0.05. RESULTS: Neither one minute nor two minutes RIs maintained the PT and TW throughout the three sets (p<0.05. However, at 60°/s, two minutes RIs enabled better PT and TW in the second and third sets than one minute RIs (p<0.05. At 180°/s, two minutes RIs were only better (p<0.05 than one minute RIs for TW in the third set. CONCLUSION: This study indicated that, during an isokinetic

  4. Development of the Young Brain

    Medline Plus

    Full Text Available ... items) Brain Anatomy and Physiology (9 items) RDoC (4 items) Research Funding (2 items) Training (1 item) Other Treatments (11 items) Alzheimer’s Disease (2 items) Coping with Traumatic Events (3 items) Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For ...

  5. Young Children's Concepts of Shape.

    Science.gov (United States)

    Clements, Douglas H.; Swaminathan, Sudha; Hannibal, Mary Anne Zeitler; Sarama, Julie

    1999-01-01

    Investigates, by conducting individual clinical interviews of 97 children ages 3 to 6, the criteria preschool children use to distinguish members of a class of shapes from other figures, emphasizing identification and descriptions of shapes and reasons for these identifications. Concludes that young children initially form schemas on the basis of…

  6. Writing in Young Deaf Children

    Science.gov (United States)

    Williams, Cheri; Mayer, Connie

    2015-01-01

    The authors conducted an integrative review of the research literature on the writing development, writing instruction, and writing assessment of young deaf children ages 3 to 8 years (or preschool through third grade) published between 1990 and 2012. A total of 17 studies were identified that met inclusion criteria. The analysis examined research…

  7. Strength Development for Young Adolescents

    Science.gov (United States)

    McDaniel, Larry W.; Jackson, Allen; Gaudet, Laura

    2009-01-01

    Participation in strength training is important for older children or young adolescences who wish to improve fitness or participate in sports. When designing strength training programs for our youth this age group is immature anatomically, physiologically, and psychologically. For the younger or inexperienced group the strength training activities…

  8. Grief: Helping Young Children Cope

    Science.gov (United States)

    Wood, Frances B.

    2008-01-01

    In their role as caregivers supporting the children they teach, it is important for teachers to understand the grieving process and recognize symptoms of grief. The author explains Elisabeth Kubler-Ross's five stages of grief and offers 10 classroom strategies to help young children cope with their feelings.

  9. Young Women, Sports, and Science

    Science.gov (United States)

    Hanson, Sandra L.

    2007-01-01

    This article examines young women's access to two traditionally male domains, sport and science, from two perspectives. The structural approach suggests that sport and science are stratified by gender and have historically been chilly climates for women. The Critical approach argues that structure and agency are important in understanding sources…

  10. YOUNG ADULTS (20 - 35 YEARS)

    African Journals Online (AJOL)

    Chantel

    Young adults are especially distressed by skin conditions that are uncomfortable, disfiguring or ... The cause is unknown, and unlikely to result from repeated shaving or short hair cutting. It ... It is important to exclude drug causes such as lithium .... occur within the hair follicles covering most of the ..... especially in children.

  11. Sexual behaviour in young people.

    Science.gov (United States)

    Gerressu, Makeda; Stephenson, Judith M

    2008-02-01

    The purpose of this review was to synthesize major research findings in relation to young people and sexual behaviour from the period 2006-2007. We found several key reviews that advance knowledge in the field of young people and sexual behaviour, including observational studies, both qualitative and quantitative, and intervention studies designed to reduce sexual transmission of HIV in both developed and developing countries. Other reviews focused on same-sex behaviours, victimization within relationships, HIV infection/sexually transmitted infection in travellers, prevention of HIV/sexually transmitted infection and the determinants of sexual behaviour in young people. Powerful and consistent forces sustain gender differences in sexual behaviour. The design of interventions to reduce sexual risk behaviour should take account of these forces that help explain young people's sexual behaviour. Knowledge about the kind of interventions that reduce risk behaviour and should be implemented has improved, although the impact on health outcomes such as pregnancy and HIV/sexually transmitted infection is often uncertain. Effective school sex education needs to be part of much broader strategies to improve sexual health, and there is an urgent need for better evaluation of interventions, especially community interventions. Further longitudinal studies are needed to provide insight into the development of relationships and sexual behaviour as well as the course of acculturation.

  12. Avoid Overtraining in Young Athletes

    Science.gov (United States)

    Rearick, Matt; Creasy, John; Buriak, Jim

    2011-01-01

    Each year many young athletes suffer injuries from overtraining. According to the existing literature, strategies do exist to help control this growing problem. This article explores the basic nature of training and overtraining, with a particular emphasis on endurance athletes. Several psychological factors are highlighted as the first clear…

  13. Report on the Young 2000

    NARCIS (Netherlands)

    K. Wittebrood; Saskia Keuzenkamp

    2000-01-01

    Original title: Rapportage jeugd 2000. The emphasis in the Report on the Young 2000 (Rapportage Jeugd 2000) is on events and situations which occur in the transition from youth to adulthood. There is an impression that the changes that have taken place in Dutch society in recent decades have

  14. YOUNG CITY,BIG PARTY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Shenzhen Universiade unites the world’s young people through sports with none of the usual hoop-la, no fireworks, no grand performances by celebrities and superstars, the Shenzhen Summer Universiade lowered the curtain on a big party for youth and college students on August 23.

  15. Positive Psychology: Transforming Young Lives

    Science.gov (United States)

    Brendtro, Larry K.; Mitchell, Martin L.

    2011-01-01

    To reach responsible independence, young people must become invested in setting their life course. A rich history of research and practice shows that democratic group climates foster autonomy and prosocial behavior. This article explores principles and practices for creating positive peer cultures to develop strengths and help youth meet their…

  16. Motivating young people for education

    DEFF Research Database (Denmark)

    Cort, Pia

    2013-01-01

    The article explores the issue of motivation in policy and practice. The argument is that the folk high schools and the tradition of liberal education offer a learning environment where a number of psychological needs are satisfied among the young people leading to a motivation for learning whereas...

  17. Interdisciplinarity and young rural researchers

    NARCIS (Netherlands)

    Derkzen, P.H.M.; Mustakangas, E.; Gambino, M.; Kucerova, E.

    2006-01-01

    The European Society for Rural Sociology (ESRS) organised a round table discussion for young rural researchers at the XXI ESRS Congress, 22-26 August, 2005 in Keszthely, Hungary. In the discussion, participants focused on interdisciplinarity in rural research from their own personal points of view b

  18. Young People's Crimes

    Institute of Scientific and Technical Information of China (English)

    许爱平

    2002-01-01

    Crime is a very serious problem in Britain. One sort of crime which particularly worries people is juvenile crimes-that is, crimes committed (犯罪) by young. people.For some years juvenile crimes have been increasing.There are two main sorts of juvenile crimes:stealing and violence(暴力).

  19. Young British Art / Hanno Soans

    Index Scriptorium Estoniae

    Soans, Hanno, 1974-

    2001-01-01

    1990ndate kunsti muutumisest. Inglise kunstniku Peter Daviese maalist "Kuum esimene sada" (1996), Gavin Turki vahakujuna valminud autoportreest "Pop". "Young British Art'i" uuskunstist ja Jasper Zoova installatsioonist "F1". Eri analüüsivõimalusi pakkuvatest töödest (Marko Laimre & Ene-Liis Semperi 2000. a. novembri ühisnäituse osa töid).

  20. Nutrient Needs of Young Athletes.

    Science.gov (United States)

    Willenberg, Barbara; Hemmelgarn, Melinda

    1991-01-01

    Explains the nutritional requirements of children and adolescents, and the physiological roles of the major nutrients. Details the nutrient needs of young athletes, including pre- and postgame meals and fluid replacement. Discusses eating disorders and obesity. Advocates a diet rich in complex carbohydrates. (BC)

  1. Sports Nutrition for Young Athletes

    Science.gov (United States)

    Cotugna, Nancy; Vickery, Connie E.; McBee, Sheldon

    2005-01-01

    Nutritional needs for peak athletic performance include sufficient calorie intake, adequate hydration, and attention to timing of meals. Student athletes and their advisors often are misinformed or have misconceptions about sports nutrition. This paper identifies nutritional needs of young athletes, reviews common misconceptions, and examines the…

  2. Never Too Young to Orienteer.

    Science.gov (United States)

    Lavine, Carolyn

    1992-01-01

    Describes orienteering courses for children, including courses that introduce young children to the idea of navigating in the outdoors and courses that teach map and compass skills and problem-solving techniques to older children. Lists sources of information and references. (SV)

  3. Sports Nutrition for Young Athletes

    Science.gov (United States)

    Cotugna, Nancy; Vickery, Connie E.; McBee, Sheldon

    2005-01-01

    Nutritional needs for peak athletic performance include sufficient calorie intake, adequate hydration, and attention to timing of meals. Student athletes and their advisors often are misinformed or have misconceptions about sports nutrition. This paper identifies nutritional needs of young athletes, reviews common misconceptions, and examines the…

  4. Young Adults' Choices for 2008

    Science.gov (United States)

    Journal of Adolescent & Adult Literacy, 2008

    2008-01-01

    This article presents annotations of 30 trade books on the 2008 list of Young Adults' Choices that are the result of voting by students in five different regions of the United States. Trade books (books other than textbooks) published in 2006 were submitted by more than 50 publishers. Each book had to have at least two positive reviews from…

  5. Writing in Young Deaf Children

    Science.gov (United States)

    Williams, Cheri; Mayer, Connie

    2015-01-01

    The authors conducted an integrative review of the research literature on the writing development, writing instruction, and writing assessment of young deaf children ages 3 to 8 years (or preschool through third grade) published between 1990 and 2012. A total of 17 studies were identified that met inclusion criteria. The analysis examined research…

  6. Young Fans for Big Brands

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    More young Chinese people are becoming the main consumers of luxury goods in China Liu Fei goes to Europe from Beijing twice a year on business.Every time she has a long list of items that her friends ask her

  7. Fact Sheet: Vulnerable Young Children

    Science.gov (United States)

    Shaw, Evelyn, Comp.; Goode, Sue, Comp.

    2008-01-01

    This fact sheet provides data on infants, toddlers and young children who are experiencing high stress as a result of a number of risk factors specifically identified in the Individuals with Disabilities Education Improvement Act of 2004 (IDEA 2004), including substantiated abuse or neglect, foster care placement, homelessness, exposure to family…

  8. Grief: Helping Young Children Cope

    Science.gov (United States)

    Wood, Frances B.

    2008-01-01

    In their role as caregivers supporting the children they teach, it is important for teachers to understand the grieving process and recognize symptoms of grief. The author explains Elisabeth Kubler-Ross's five stages of grief and offers 10 classroom strategies to help young children cope with their feelings.

  9. Young British Art / Hanno Soans

    Index Scriptorium Estoniae

    Soans, Hanno, 1974-

    2001-01-01

    1990ndate kunsti muutumisest. Inglise kunstniku Peter Daviese maalist "Kuum esimene sada" (1996), Gavin Turki vahakujuna valminud autoportreest "Pop". "Young British Art'i" uuskunstist ja Jasper Zoova installatsioonist "F1". Eri analüüsivõimalusi pakkuvatest töödest (Marko Laimre & Ene-Liis Semperi 2000. a. novembri ühisnäituse osa töid).

  10. Letter to a Young Writer.

    Science.gov (United States)

    Hirsch, Edward

    2002-01-01

    Describes, in the form of a letter to a young writer, how the author celebrates the pendulous life of the poet: from arrogance to uncertainty, from misstep to breakthrough. Emphasizes the sustaining force of reading and the need to be initiated into one's own work by the work of others. (SG)

  11. Development of the Young Brain

    Medline Plus

    Full Text Available ... items) RDoC (4 items) Research Funding (2 items) Training (1 item) Other Treatments (11 items) Alzheimer’s Disease (2 items) Coping with Traumatic Events (3 items) Institute Announcements (24 items) Development of the Young Brain May 2, 2011 For ...

  12. Promote "Connections" for Young Adolescents.

    Science.gov (United States)

    Jacoby, Monica

    1987-01-01

    The emotional, social, intellectual, and physical needs of young people from 10 to 15 years old are being increasingly recognized in the schools, but the activities of these students after school are just beginning to be considered in terms of their effects on adolescents' academic and personal growth. Early in 1985, the University of North…

  13. Supporting Young Children with Disabilities

    Science.gov (United States)

    Hebbeler, Kathleen; Spiker, Donna

    2016-01-01

    What do we know about young children with delays and disabilities, and how can we help them succeed in prekindergarten through third grade? To begin with, Kathleen Hebbeler and Donna Spiker write, identifying children with delays and disabilities to receive specialized services under the Individuals with Disabilities Education Act poses several…

  14. Financial planning for young households

    DEFF Research Database (Denmark)

    Pedersen, Anne Marie Boiden; Weissensteiner, Alex; Poulsen, Rolf

    2013-01-01

    We analyze the financial planning problems of young households whose main decisions are how to finance the purchase of a house (liabilities) and how to allocate investments in pension savings schemes (assets). The problems are solved using a multi-stage stochastic programming model where...

  15. Parents' Perspectives on Young Suicide

    Science.gov (United States)

    Stanley, Nicky

    2005-01-01

    Strategies for the prevention of adolescent suicide are frequently designed to identify those young people who represent a high risk in order that services and support can be effectively targeted. This study explored the experiences of parents who had lost a child through suicide. The findings suggest that the range of behaviours perceived by…

  16. Adolescents and Young Adults with Cancer

    Science.gov (United States)

    ... Adults with Cancer Reports, Research, and Literature Quiz Adolescents and Young Adults with Cancer View this video ... Fund for Young Adults Vital Options Teens and Adolescents CureSearch Starlight Children's Foundation Teens Living with Cancer ...

  17. Signed Young Modules and Simple Specht Modules

    OpenAIRE

    Danz, Susanne; Lim, Kay Jin

    2015-01-01

    By a result of Hemmer, every simple Specht module of a finite symmetric group over a field of odd characteristic is a signed Young module. While Specht modules are parametrized by partitions, indecomposable signed Young modules are parametrized by certain pairs of partitions. The main result of this article establishes the signed Young module labels of simple Specht modules. Along the way we prove a number of results concerning indecomposable signed Young modules that are of independent inter...

  18. Simulation Frames: Young Adult Dystopian Cinema

    OpenAIRE

    Alison Tedman

    2015-01-01

    This article examines the ways in which Young Adult dystopian film Divergent (2014) successfully repurposes dystopia for a young demographic, making dystopia an aesthetically appealing space for heroic adventure. The film recombines Young Adult literary tropes with film conventions including those of science fiction. Divergent and other Young Adult dystopian films modify the potential for social critique associated with canonic dystopian fiction. The article’s critical framework includes t...

  19. Simulation Frames: Young Adult Dystopian Cinema

    OpenAIRE

    Alison Tedman

    2015-01-01

    This article examines the ways in which Young Adult dystopian film Divergent (2014) successfully repurposes dystopia for a young demographic, making dystopia an aesthetically appealing space for heroic adventure. The film recombines Young Adult literary tropes with film conventions including those of science fiction. Divergent and other Young Adult dystopian films modify the potential for social critique associated with canonic dystopian fiction. The article’s critical framework includes t...

  20. Helping Young People Engage with Scientists

    Science.gov (United States)

    Leggett, Maggie; Sykes, Kathy

    2014-01-01

    There can be multiple benefits of scientists engaging with young people, including motivation and inspiration for all involved. But there are risks, particularly if scientists do not consider the interests and needs of young people or listen to what they have to say. We argue that "dialogue" between scientists, young people and teachers…