WorldWideScience

Sample records for binary exo 0748-676

  1. The eclipsing bursting X-ray binary EXO 0748-676 revisited by XMM-Newton

    CERN Document Server

    Bonnet-Bidaud, J M; Ferrando, P; Bennie, P J; Kendziorra, E

    2001-01-01

    The bright eclipsing and bursting low-mass X-ray binary EXO 0748-676 has been observed at several occasions by XMM-Newton during the initial calibration and performance verification (CAL/PV) phase. We present here the results obtained from observations with the EPIC cameras. Apart from several type-I X-ray bursts, the source shows a high degree of variability with the presence of soft flares. The wide energy coverage and high sensitivity of XMM-Newton allows for the first time a detailed description of the spectral variability. The source is found to be the superposition of a central (~2 10^8 cm) Comptonized emission, most probably a corona surrounding the inner edge of an accretion disk, associated with a more extended (~3 10^10 cm) thermal halo at a typical temperature of ~0.6 keV with an indication of non-solar abundances. Most of the variations of the source can be accounted for by a variable absorption affecting only the central comptonized component and reaching up to NH ~1.3 10^23 cm^{-2}. The characte...

  2. A Strong X-Ray Burst from the Low Mass X-Ray Binary EXO0748-676

    OpenAIRE

    Wolff, Michael T.; Becker, Peter A.; Ray, Paul S.; Wood, Kent S.

    2005-01-01

    We have observed an unusually strong X-ray burst as a part of our regular eclipse timing observations of the low mass binary system EXO0748-676. The burst peak flux was 5.2x10^-8 ergs cm^-2 s^-1, approximately five times the normal peak X-ray burst flux observed from this source by RXTE. Spectral fits to the data strongly suggest that photospheric radius expansion occurred during the burst. In this Letter we examine the properties of this X-ray burst, which is the first example of a radius ex...

  3. What can the redshift observed in EXO 0748-676 tell us?

    CERN Document Server

    Xu, R X

    2003-01-01

    The mass-radius relations for bare and crusted strange stars are calculated with bag model. Comparing these relations with the observed one derived from redshift, we address that the conclusions, that EXO 0748-676 can not be a strange star, is incorrect. Various strange star models can show that EXO 0748-676 could have a mass of (1.3 ~ 1.7) M_sun and a radius of (8.2 ~ 10.6) km. It is proposed that some nascent strange stars could be bare and have mass $\\sim 0.1M_\\odot$, whereas their mass increases during a long accretion history.

  4. What can the redshift observed in EXO 0748-676 tell us?

    OpenAIRE

    Xu, R. X.

    2002-01-01

    The mass-radius relations for bare and crusted strange stars are calculated with the bag model. Comparing these relations with the observed one derived from redshift, we address that the conclusion, that EXO 0748-676 can not be a strange star, is incorrect. Various strange star models can show that EXO 0748-676 could have a mass of (1.3 ~ 1.7) M_sun and a radius of (8.4 ~ 11.4) km. It is proposed that some nascent strange stars could be bare and have mass \\~ 0.1 M_sun, whereas their masses in...

  5. Disentangling x-ray reprocessing sites in exo 0748{676

    Directory of Open Access Journals (Sweden)

    R. I. Hynes

    2004-01-01

    Full Text Available Presentamos los primeros resultados de un estudio coordinado en m ultiples longitudes de onda de la estrella de neutrones de la binaria de baja masa de rayos X, EXO 0748-676 (UY Vol. Se obtuvieron datos UV r apidos, de rayos X y opticos, incluyendo tanto informaci on espectral como temporal. Discutimos c omo este estudio nos permite indagar sobre cu al es la distribuci on de temperatura dentro de la binaria y por lo tanto, sobre la geometr a y la e ciencia de la irradiaci on de rayos X

  6. Dynamical constraints on the neutron star mass in EXO 0748-676

    OpenAIRE

    T. Muñoz-Darias(Oxford University, United Kingdom); Casares, J.; O'Brien, K.; Steeghs, D; Martinez-Pais, I. G.; Cornelisse, R.; Charles, P. A.

    2009-01-01

    We present VLT intermediate resolution spectroscopy of UY Vol, the optical counterpart of the LMXB X-ray burster EXO 0748-676. By using Doppler tomography we detect narrow components within the broad He II 4542 A, 4686 A and 5412 A emission lines. The phase, velocity and narrowness of these lines are consistent with their arising from the irradiated hemisphere of the donor star, as has been observed in a number of LMXBs. Under this assumption we provide the first dynamical constraints on the ...

  7. Dynamical constraints on the neutron star mass in EXO 0748-676

    CERN Document Server

    Muñoz-Darias, T; O'Brien, K; Steeghs, D; Martínez-Pais, I G; Cornelisse, R; Charles, P A

    2009-01-01

    We present VLT intermediate resolution spectroscopy of UY Vol, the optical counterpart of the LMXB X-ray burster EXO 0748-676. By using Doppler tomography we detect narrow components within the broad He II 4542 A, 4686 A and 5412 A emission lines. The phase, velocity and narrowness of these lines are consistent with their arising from the irradiated hemisphere of the donor star, as has been observed in a number of LMXBs. Under this assumption we provide the first dynamical constraints on the stellar masses in this system. In particular, we measure K_2>K_em = 300 +/- 10 km/s. Using this value we derive 1 M_sun 1.5 M_sun for the case of a main sequence companion star. Our results are consistent with the presence of a massive neutron star as has been suggested by Ozel (2006), although we cannot discard the canonical value of ~1.4 M_sun.

  8. Discovery of long-term superorbital periodicities in the pseudo-transient LMXBs: IGR J17098-3628 and EXO0748-676

    CERN Document Server

    Kotze, M M; Crause, L A

    2009-01-01

    Long-term monitoring of the recently discovered X-ray transient, IGR J17098-3628, by the All Sky Monitor on board the Rossi X-ray Timing Explorer, has shown that it displays a long term (~163d) quasi-periodic modulation in the data spanning its "active" state (i.e. approximately MJD 53450-54200). Furthermore, this light-curve is not typical of "classical" soft X-ray transients, in that J17098-3628 has remained active since its initial discovery, and may be more akin to the pseudo-transient EXO0748-676, which is now classified as a persistent Low Mass X-ray Binary. However, EXO0748-676 recently entered a more active phase (since approximately MJD 53050), since when we find that it too displays a quasi-periodic modulation (~181d) in its light-curve. This must be a "superorbital" modulation, as the orbital period of EXO0748-676 is well established (3.8hrs), and hence we interpret both objects' long periods as representing some intrinsic properties of the accretion disc (such as coupled precessional and warping e...

  9. Progressive Covering of the ADC during Dipping in the LMXB XBT 0748-676

    CERN Document Server

    Church, M J; Dotani, T; Asai, K

    1998-01-01

    We report results of analysis of the ASCA observation of 1993, May 7th of the dipping LMXB source XBT 0748-676, and propose a new explanation of the spectral evolution in dipping in this source. We show that the non-dip and dip spectra in several intensity bands are well fitted using the same physical model that we have previously shown gives good explanations of several dipping sources, consisting of point source blackbody emission from the neutron star, plus extended Comptonised emission from the accretion disk corona (ADC), with progressive covering of the ADC during dipping. Best fit values of kT_bb = 1.99 +/- 0.16 keV and power law photon index Gamma = 1.70 +/- 0.16 are found. The strong excess below 1 keV was well fitted by a Gaussian line at ~0.65 keV. In dipping, good fits were obtained by allowing it to be covered by the same progressive covering factor as the extended continuum emission, providing strong evidence that the line originates in the ADC. By using our two-component model we show that the ...

  10. On the geometric nature of low-frequency quasi-periodic oscillations in neutron-star low-mass X-ray binaries

    CERN Document Server

    Homan, Jeroen; Remillard, Ronald A

    2015-01-01

    We report on a detailed analysis of the so-called ~1 Hz quasi-periodic oscillation (QPO) in the eclipsing and dipping neutron-star low-mass X-ray binary EXO 0748-676. This type of QPO has previously been shown to have a geometric origin. Our study focuses on the evolution of the QPO as the source moves through the color-color diagram, in which it traces out an atoll-source-like track. The QPO frequency increases from ~0.4 Hz in the hard state to ~25 Hz as the source approaches the soft state. Combining power spectra based on QPO frequency reveals additional features that strongly resemble those seen in non-dipping/eclipsing atoll sources. We show that the low-frequency QPOs in atoll sources and the ~1 Hz QPO in EXO 0748-676 follow similar relations with respect to the noise components in their power spectra. We conclude that the frequencies of both types of QPOs are likely set by (the same) precession of a misaligned inner accretion disk. For high-inclination systems, like EXO 0748-676, this results in modula...

  11. Suzaku Observation of Be/X-ray Binary Pulsar EXO 2030+375

    CERN Document Server

    Naik, Sachindra

    2014-01-01

    In this paper we study the timing and spectral properties of Be/X-ray binary pulsar EXO 2030+375 using a $Suzaku$ observation on 2012 May 23, during a less intense Type I outburst. Pulsations were clearly detected in the X-ray light curves at a barycentric period of 41.2852 s which suggests that the pulsar is spinning-up. The pulse profiles were found to be peculiar e.g. unlike that obtained from the earlier Suzaku observation on 2007 May 14. A single-peaked narrow profile at soft X-rays (0.5-10 keV range) changed to a double-peaked broad profile in 12-55 keV energy range and again reverted back to a smooth single-peaked profile at hard X-rays (55-70 keV range). The 1.0-100.0 keV broad-band spectrum of the pulsar was found to be well described by three continuum models such as (i) a partial covering high energy cut-off power-law model, (ii) a partially absorbed power-law with high-energy exponential rolloff and (iii) a partial covering Negative and Positive power law with EXponential (NPEX) continuum model. U...

  12. Hysteresis in the spectral states of the neutron star low-mass X-ray binary EXO 1745-248

    CERN Document Server

    Mukherjee, Arunava

    2011-01-01

    We study the low-frequency timing properties and the spectral state evolution of the transient neutron star low-mass X-ray binary EXO 1745-248 using the entire Rossi X-ray Timing Explorer Proportional Counter Array data. We tentatively conclude that EXO 1745-248 is an atoll source, and report the discovery of a ~ 0.45 Hz low-frequency quasi-periodic oscillation and ~ 10 Hz peaked noises. If it is an atoll, this source is unusual because (1) instead of a `C'-like curve, it traced a clear overall clockwise hysteresis curve in each of the colour-colour diagram and the hardness-intensity diagram; and (2) the source took at least 2.5 months to trace the softer banana state, as opposed to a few hours to a day, which is typical for an atoll source. The shape of the hysteresis track was intermediate between the characteristic `q'-like curves of several black hole systems and `C'-like curves of atolls, implying that EXO 1745-248 is an important source for the unification of the black hole and neutron star accretion pr...

  13. Disc-Jet Coupling in the Terzan 5 Neutron Star X-ray Binary EXO 1745$-$248

    CERN Document Server

    Tetarenko, A J; Sivakoff, G R; Tremou, E; Linares, M; Tudor, V; Miller-Jones, J C A; Heinke, C O; Chomiuk, L; Strader, J; Altamirano, D; Degenaar, N; Maccarone, T; Patruno, A; Sanna, A; Wijnands, R

    2016-01-01

    We present the results of VLA, ATCA, and Swift XRT observations of the 2015 outburst of the transient neutron star X-ray binary (NSXB), EXO 1745$-$248, located in the globular cluster Terzan 5. Combining (near-) simultaneous radio and X-ray measurements we measure a correlation between the radio and X-ray luminosities of $L_R\\propto L_X^\\beta$ with $\\beta=1.68^{+0.10}_{-0.09}$, linking the accretion flow (probed by X-ray luminosity) and the compact jet (probed by radio luminosity). While such a relationship has been studied in multiple black hole X-ray binaries (BHXBs), this work marks only the third NSXB with such a measurement. Constraints on this relationship in NSXBs are strongly needed, as comparing this correlation between different classes of XB systems is key in understanding the properties that affect the jet production process in accreting objects. Our best fit disc-jet coupling index for EXO 1745$-$248 is consistent with the measured correlation in NSXB 4U 1728$-$34 ($\\beta=1.5\\pm 0.2$) but inconsi...

  14. The impact of Gaia and LSST on binary stars and exo-planets

    CERN Document Server

    Eyer, L; Mowlavi, N; North, P; Triaud, A; Barblan, F; Siopis, C; Guy, L; Tingley, B; Zucker, S; Evans, D W; Wyrzykowski, L; Suveges, M; Ivezic, Z

    2012-01-01

    Two upcoming large scale surveys, the ESA Gaia and LSST projects, will bring a new era in astronomy. The number of binary systems that will be observed and detected by these projects is enormous, estimations range from millions for Gaia to several tens of millions for LSST. We review some tools that should be developed and also what can be gained from these missions on the subject of binaries and exoplanets from the astrometry, photometry, radial velocity and their alert systems.

  15. Excess molar volume along with viscosity, refractive index and relative permittivity for binary mixtures of exo-tetrahydrodicyclopentadiene with four octane isomers

    International Nuclear Information System (INIS)

    Highlights: • Binary mixtures of JP-10 with octane isomers are studied as model hydrocarbon fuels. • Density, viscosity, refractive index and relative permittivity are determined. • Excess molar volumes and viscosity deviations are calculated and correlated. - Abstract: The fundamental physical properties including density, viscosity, refractive index and relative permittivity, have been measured for binary mixtures of exo-tetrahydrodicyclopentadiene (JP-10) with four octane isomers (n-octane, 3-methylheptane, 2,4-dimethylhexane and 2,2,4-trimethylpentane) over the whole composition range at temperatures T = (293.15 to 313.15) K and pressure p = 0.1 MPa. The values of excess molar volume (VmE), viscosity deviation (Δη), refractive index deviation (ΔnD) and relative permittivity deviation (Δεr) are then calculated. All of the values of VmE and Δη are observed to be negative, while those of ΔnD and Δεr are close to zero. The effects of temperature and composition on the variation of VmE values are discussed. The negative values of VmE and Δη are conductive to high-density and low-resistance of fuels, which is favorable for the design and preparation of advanced hydrocarbon fuels

  16. Status of EXO-200

    OpenAIRE

    Ackerman, Nicole

    2009-01-01

    EXO-200 is the first phase of the Enriched Xenon Observatory (EXO) experiment, which searches for neutrinoless double beta decay in 136Xe to measure the mass and probe the Majorana nature of the neutrino. EXO-200 consists of 200 kg of liquid Xe enriched to 80% in 136Xe in an ultra-low background TPC. Energy resolution is enhanced through the simultaneous collection of scintillation light using Large Area Avalanche Photodiodes (LAAPD's) and ionization charge. It is being installed at the WIPP ...

  17. Status of EXO-200

    CERN Document Server

    Ackerman, Nicole

    2009-01-01

    EXO-200 is the first phase of the Enriched Xenon Observatory (EXO) experiment, which searches for neutrinoless double beta decay in 136Xe to measure the mass and probe the Majorana nature of the neutrino. EXO-200 consists of 200 kg of liquid Xe enriched to 80% in 136Xe in an ultra-low background TPC. Energy resolution is enhanced through the simultaneous collection of scintillation light using Large Area Avalanche Photodiodes (LAAPD's) and ionization charge. It is being installed at the WIPP site in New Mexico, which provides a 2000 meter water-equivalent overburden. EXO-200 will begin taking data in 2009, with the expected two-year sensitivity to the half-life for neutrinoless double beta decay of 6.4 10^25 years. According to the most recent nuclear matrix element calculations, this corresponds to an effective Majorana neutrino mass of 0.13 to 0.19 eV. It will also measure the two neutrino mode for the first time in 136Xe.

  18. Status of EXO-200

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, Nicole; /SLAC

    2011-12-06

    EXO-200 is the first phase of the Enriched Xenon Observatory (EXO) experiment, which searches for neutrinoless double beta decay in {sup 136}Xe to measure the mass and probe the Majorana nature of the neutrino. EXO-200 consists of 200 kg of liquid Xe enriched to 80% in {sup 136}Xe in an ultra-low background TPC. Energy resolution is enhanced through the simultaneous collection of scintillation light using Large Area Avalanche Photodiodes (LAAPD's) and ionization charge. It is being installed at the WIPP site in New Mexico, which provides a 2000 meter water-equivalent overburden. EXO-200 will begin taking data in 2009, with the expected two-year sensitivity to the half-life for neutrinoless double beta decay of 6.4 x 10{sup 25} years. According to the most recent nuclear matrix element calculations, this corresponds to an effective Majorana neutrino mass of 0.13 to 0.19 eV. It will also measure the two neutrino mode for the first time in {sup 136}Xe.

  19. The Exo-S probe class starshade mission

    Science.gov (United States)

    Seager, Sara; Turnbull, Margaret; Sparks, William; Thomson, Mark; Shaklan, Stuart B.; Roberge, Aki; Kuchner, Marc; Kasdin, N. Jeremy; Domagal-Goldman, Shawn; Cash, Webster; Warfield, Keith; Lisman, Doug; Scharf, Dan; Webb, David; Trabert, Rachel; Martin, Stefan; Cady, Eric; Heneghan, Cate

    2015-09-01

    Exo-S is a direct imaging space-based mission to discover and characterize exoplanets. With its modest size, Exo-S bridges the gap between census missions like Kepler and a future space-based flagship direct imaging exoplanet mission. With the ability to reach down to Earth-size planets in the habitable zones of nearly two dozen nearby stars, Exo-S is a powerful first step in the search for and identification of Earth-like planets. Compelling science can be returned at the same time as the technological and scientific framework is developed for a larger flagship mission. The Exo-S Science and Technology Definition Team studied two viable starshade-telescope missions for exoplanet direct imaging, targeted to the $1B cost guideline. The first Exo-S mission concept is a starshade and telescope system dedicated to each other for the sole purpose of direct imaging for exoplanets (The "Starshade Dedicated Mission"). The starshade and commercial, 1.1-m diameter telescope co-launch, sharing the same low-cost launch vehicle, conserving cost. The Dedicated mission orbits in a heliocentric, Earth leading, Earth-drift away orbit. The telescope has a conventional instrument package that includes the planet camera, a basic spectrometer, and a guide camera. The second Exo-S mission concept is a starshade that launches separately to rendezvous with an existing on-orbit space telescope (the "Starshade Rendezvous Mission"). The existing telescope adopted for the study is the WFIRST-AFTA (Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Asset). The WFIRST-AFTA 2.4-m telescope is assumed to have previously launched to a Halo orbit about the Earth-Sun L2 point, away from the gravity gradient of Earth orbit which is unsuitable for formation flying of the starshade and telescope. The impact on WFIRST-AFTA for starshade readiness is minimized; the existing coronagraph instrument performs as the starshade science instrument, while formation guidance is handled by the

  20. SPICA Coronagraph for the Direct Observation of Exo-Planets

    Science.gov (United States)

    Enya, K.; S. W. Group

    2011-12-01

    We present a mid-infrared coronagraph which targets the direct observation of exo-planets for the Space Infrared telescope for Cosmology and Astrophysics (SPICA). Study and experiment are ongoing for an coronagraph for SPICA, and this coronagraph is currently regarded as an option of the focal plane instruments. The primary target of the SPICA coronagraph is the direct imaging and spectroscopy of exo-planets in infrared. The SPICA mission gives us a unique opportunity for high-contrast observations, because of its large telescope aperture (3.5 m), the clean point-spread function provided by the monolithic telescope mirrors, and the capability for infrared observations from space. Laboratory experiments were performed with a visible laser to demonstrate the principles of the coronagraph. In an experiment using a binary-shaped pupil coronagraph, it was demonstrated that the contrast exceeded the requirement of SPICA, 10×10-6. A coronagraph obtained using a binary-shaped pupil mask is a baseline solution for SPICA because of its feasibility and robustness, while the use of a phase-induced amplitude apodization/binary-mask hybrid coronagraph is also considered as an option. Further developments are ongoing in order to realize a mid-infrared coronagraph for SPICA. Considering SPICA to be an essential platform for coronagraphic studies, and taking into account the progress of key technologies, we propose to develop a mid-infrared coronagraph instrument for SPICA and to perform the direct observation of exo-planets by using it.

  1. Exo-endo cellulase fusion protein

    Science.gov (United States)

    Bower, Benjamin S.; Larenas, Edmund A.; Mitchinson, Colin

    2012-01-17

    The present invention relates to a heterologous exo-endo cellulase fusion construct, which encodes a fusion protein having cellulolytic activity comprising a catalytic domain derived from a fungal exo-cellobiohydrolase and a catalytic domain derived from an endoglucanase. The invention also relates to vectors and fungal host cells comprising the heterologous exo-endo cellulase fusion construct as well as methods for producing a cellulase fusion protein and enzymatic cellulase compositions.

  2. Result from, and status of, EXO-200

    Science.gov (United States)

    MacLellan, Ryan; EXO-200 Collaboration

    2016-03-01

    EXO-200 has provided one of the most sensitive searches for neutrinoless double-beta decay utilizing 175kg of enriched liquid xenon in an ultra-low background time projection chamber. This detector has demonstrated excellent energy resolution and background rejection capabilities. Using the first two years of data, EXO-200 has set a limit of 1 . 1 ×1025 y at 90% C.L. on the neutrinoless double-beta decay half-life of 136Xe. The experiment has experienced a brief hiatus in data taking during a temporary shutdown of its host facility: the Waste Isolation Pilot Plant. EXO-200 expects to resume data taking in earnest this fall with upgraded detector electronics. Results from the analysis of EXO-200 data and an update on the current status of EXO-200 will be presented.

  3. Status and Results from the EXO Collaboration

    Directory of Open Access Journals (Sweden)

    Albert Joshua

    2014-03-01

    Full Text Available The Enriched Xenon Observatory (EXO is an experimental program searching for neutrinoless double-beta decay using 136Xe. Such a search can shed light on the Majorana nature of the neutrino (whether the neutrino is its own anti-particle, the absolute mass scale of neutrinos, and beyond standard model processes that violate lepton number conservation. The first phase of the experiment, EXO-200, uses 200 kg of xenon with 80% enrichment in 136Xe in a single-phase liquid xenon time projection chamber (TPC. The double-beta decay of xenon is detected in the ultra-low background TPC by collecting both the scintillation light and the ionization charge. The detector has been taking low background physics data with enriched xenon at the Waste Isolation Pilot Plant (WIPP in New Mexico since early May 2011. The results produced from the collaboration include the first observation of two-neutrino double-beta decay of 136Xe, and a neutrinoless double-beta decay search result that places one of the most stringent limits on the effective Majorana neutrino mass. Building on the success of EXO-200, the collaboration is performing feasibility studies and R&D work for a future multi-tonne scale experiment named nEXO. During the talk, I will discuss the latest results from EXO-200 and prospects of neutrinoless double-beta decay search with both EXO-200 and nEXO.

  4. Quiescent thermal emission from neutron stars in LMXBs

    CERN Document Server

    Turlione, Anabela; Pons, José A

    2013-01-01

    The quiescent thermal emission from neutron stars in low mass X-ray binaries after active periods of intense activity in x-rays (outbursts) has been monitored. The theoretical modeling of the thermal relaxation of the neutron star crust may be used to establish constraints on the crust and envelope composition and transport properties, depending on the astrophysical scenarios assumed. We perform numerical simulations of the neutron star crust thermal evolution and compare them with inferred surface temperatures for five sources: MXB 1659-29, KS 1731-260, EXO 0748-676, XTE J1701-462 and IGR J17480-2446. We also present stationary envelope models to be used as a boundary condition for the crustal cooling models. We obtain a relation between the mass accretion rate and the temperature reached at the crust-envelope interface at the end of the active phase that accounts for early observations and reduces the number of free parameters of the problem. With this relation we are also able to set constraints to the env...

  5. ExoMars planetary protection implementation

    Science.gov (United States)

    Wall, R.; Waugh, L.; Draper, C.; Roe, M.; Pillinger, C.; Pillinger, J.

    ExoMars will be Europe s first Rover mission to the Red Planet The major aim of ExoMars is the search for evidence of extant or extinct life and as such demands the highest level of Planetary Protection PP requirements This presentation will give the latest status of the PP implementation for this Category IVc mission Areas that will be described include - PP strategy for all mission elements Carrier Descent Module Rover and Payloads - Organic contamination control - Bioburden management - Non-nominal impact provisions - AIV options and baseline strategy - Supplier and subcontractor management One of the major activities is the definition of the AIV approach for ExoMars This definition relies heavily on the confident identification of the sterilization vulnerabilities of all hardware and equipment A robust managerial and technical approach is necessary to ensure reliable sterilization compliance information is obtained A suitable approach is also necessary to ensure that no organic contamination will compromise ExoMars scientific results This will require an aseptic build for at least part of the ExoMars assembly and detailed design solutions The presentation of the activities described in this abstract is subject to award of contract by the European Space Agency

  6. The bulk composition of exo-planets

    CERN Document Server

    Gaensicke, Boris; Dufour, Patrick; Farihi, Jay; Jura, Michael; Kilic, Mukremin; Melis, Carl; Veras, Dimitri; Xu, Siyi; Zuckerman, Ben

    2015-01-01

    Priorities in exo-planet research are rapidly moving from finding planets to characterizing their physical properties. Of key importance is their chemical composition, which feeds back into our understanding of planet formation. For the foreseeable future, far-ultraviolet spectroscopy of white dwarfs accreting planetary debris remains the only way to directly and accurately measure the bulk abundances of exo-planetary bodies. The exploitation of this method is limited by the sensitivity of HST, and significant progress will require a large-aperture space telescope with a high-throughput ultraviolet spectrograph.

  7. EXO-K Into Your World

    Institute of Scientific and Technical Information of China (English)

    凤梨味的orange

    2012-01-01

    万千的等待 只为这一刻经过了100多个日夜的等待,大家期待已久的EX0正式出道,在举办showcase的那天,来自世界各地的歌迷齐聚首尔蚕室。随着《history》的音乐响起,12个少年分成EXO-K和EXO-M两队为台下的观众带来精彩的视觉盛宴。

  8. The ExoMars 2016 Landing Site

    Science.gov (United States)

    Ori, G. G.; Aboudan, A.; Pacifici, A.; Cannarsa, F.; Murana, A.; Portigliotti, S.; Marcer, A.; Lorenzoni, L.

    2015-10-01

    We present the analysis of the engineering constraints of the ExoMars 2016 landing site in order to assess the EDM landing safety The landing ellipse of ExoMars 2016 is located at Meridiani Planum. The EXM2016 ellipse is 100 km long and 15 km large, with a characterization of 110 km long and 25 km large; it covers a flat area to the west of the Opportunity landing site. The EDL operations require such landing area in line with its ballistic approach. A large number of data sets have been used for this analysis and the final outputs have been a set of maps and the final hazard assessment.

  9. Glancing through the accretion column of EXO 2030+375

    Science.gov (United States)

    Ferrigno, C.; Pjanka, P.; Bozzo, E.; Klochkov, D.; Ducci, L.; Zdziarski, A.

    2016-06-01

    The current generation of X-ray instruments is revealing more and more details about the complex magnetic field topology and the geometry of the accretion flows in highly magnetized accretion powered pulsars. We took advantage of the large collecting area and timing capabilities of the EPIC cameras to investigate the accretion geometry onto the magnetized neutron star in the high mass X-ray binary EXO 2030+375 during the rise of one of the source outburst. The X-ray luminosity was 2×10^{36} erg/s and the timing analysis revealed the presence of a narrow dip-like feature in its pulse profile that was never reported before. The width of this feature corresponds to about one hundredth of the neutron star spin period. From the results of the phase-resolved spectral analysis we suggest that this feature can be ascribed to the self-obscuration of the accretion stream passing in front of the observer line of sight. We inferred from Suzaku observation carried out in 2007 that the self-obscuration of the accretion stream might produce a significantly wider feature in the neutron star pulsed profile at higher luminosities (>˜2×10^{37} erg/s). The presence of such feature is so far unique among all known high mass X-ray binaries hosting strongly magnetized neutron stars.

  10. Glancing through the accretion column of EXO 2030+375

    Science.gov (United States)

    Ferrigno, C.; Pjanka, P.; Bozzo, E.; Klochkov, D.; Ducci, L.; Zdziarski, A.

    2016-06-01

    The current generation of X-ray instruments is revealing more and more details about the complex magnetic field topology and the geometry of the accretion flows in highly magnetized accretion powered pulsars. We took advantage of the large collecting area and timing capabilities of the EPIC cameras to investigate the accretion geometry onto the magnetized neutron star in the high mass X-ray binary EXO 2030+375 during the rise of one of the source outburst. The X-ray luminosity was 2×10^{36} erg/s and the timing analysis revealed the presence of a narrow dip-like feature in its pulse profile that was never reported before. The width of this feature corresponds to about one hundredth of the neutron star spin period. From the results of the phase-resolved spectral analysis we suggest that this feature can be ascribed to the self-obscuration of the accretion stream passing in front of the observer line of sight. We inferred from Suzaku observation carried out in 2007 that the self-obscuration of the accretion stream might produce a significantly wider feature in the neutron star pulsed profile at higher luminosities (≳2×10^{37} erg/s). The presence of such feature is so far unique among all known high mass X-ray binaries hosting strongly magnetized neutron stars.

  11. Planetary protection appraoch for ExoMars

    Science.gov (United States)

    Kminek, G.; Guarnieri, V.

    The scientific objective of the ExoMars mission is the search for life on Mars As a result of that the planetary protection category assigned to the mission is a modified category IVc The modification being that the requirements of category IVb apply along with the additional category IVc requirements As the discussion of what exactly defines a special region is still ongoing the detailed requirements for this category might have to be adjusted during phase B1 A dedicated six month subcontract released by the prime contractor in phase B1 will propose a programmatic and technical implementation of the appropriate planetary protection requirements for the ExoMars mission This contract includes a trade-off between sterile integration and terminal sterilization process proposed AIV AIT flow based on trade-off preliminary bioburden allocation proposed bioburden reduction processes disposal of cruise stage etc The preliminary result of this activity will be presented

  12. EXO-K THE FIRST HISTORY

    Institute of Scientific and Technical Information of China (English)

    凤梨味的Orange

    2012-01-01

    EXO-K还没有出道,就因大众的高度关注而接手CK牛仔代言,拍广告,拍杂志,忙得不亦乐乎,6个青涩少年正用自己的方式为行星的轨迹描绘出第一个历史。

  13. The ExoMars 2016 mission

    Science.gov (United States)

    Svedhem, Håkan; Vago, Jorge; de Groot, Rolf

    2015-11-01

    The ExoMars programme is a joint activity by the European Space Agency (ESA) and ROSCOSMOS, Russia. It consists of the ExoMars 2016 mission with the Trace Gas Orbiter, TGO, and the Entry Descent and Landing Demonstrator, Schiaparelli, and the Exomars 2018 mission which carries a lander and a rover.The TGO scientific payload consists of four instruments. These are: ACS and NOMAD, both infrared spectrometers for atmospheric measurements in solar occultation mode and in nadir mode, CASSIS, a multichannel camera with stereo imaging capability, and FREND, an epithermal neutron detector for search of subsurface hydrogen. ESA is providing the TGO spacecraft and the Schiaparelli Lander demonstrator and two of the TGO instruments and ROSCOSMOS is providing the launcher and the other two TGO instruments.After the arrival of the ExoMars 2018 mission at the surface of Mars, the TGO will handle the communication between the Earth and the Rover and lander through its UHF communication system. The 2016 mission will be launched by a Russian Proton rocket from Baikonur in January 2016 and will arrive at Mars in October the same year. This presentation will cover a description of the 2016 mission, including the spacecraft, its payload and science and the related plans for scientific operations and measurements.

  14. Glancing through the accretion column of EXO 2030+375

    CERN Document Server

    Ferrigno, C; Bozzo, E; Klochkov, D; Ducci, L; Zdziarski, A A

    2016-01-01

    We took advantage of the large collecting area and good timing capabilities of the EPIC cameras on-board XMM-Newton to investigate the accretion geometry onto the magnetized neutron star hosted in the high mass X-ray binary EXO 2030+375 during the rise of a source Type-I outburst in 2014. We carried out a timing and spectral analysis of the XMM-Newton observation as function of the neutron star spin phase. We used a phenomenological spectral continuum model comprising the required fluorescence emission lines. Two neutral absorption components are present: one covering fully the source and one only partially. The same analysis was also carried out on two Suzaku observations of the source performed during outbursts in 2007 and 2012, to search for possible spectral variations at different luminosities. The XMM-Newton data caught the source at an X-ray luminosity of $2\\times10^{36}$ erg s$^{-1}$ and revealed the presence of a narrow dip-like feature in its pulse profile that was never reported before. The width o...

  15. The exo-metabolome in filamentous fungi

    DEFF Research Database (Denmark)

    Thrane, Ulf; Andersen, Birgitte; Frisvad, Jens Christian;

    2007-01-01

    Filamentous fungi are a diverse group of eukaryotic microorganisms that have a significant impact on human life as spoilers of food and feed by degradation and toxin production. They are also most useful as a source of bulk and fine chemicals and pharmaceuticals. This chapter focuses on the exo......-metabolome in filamentous fungi, which comprises more than 30,000 known secondary metabolites. Profiles of this diverse range of secondary metabolites have, for more than 25 years, been central in development of fungal systematics, taxonomy, and ecology, today integrated in a multidisciplinary and polyphasic approach...

  16. The ExoMars 2016 Mission

    Science.gov (United States)

    Svedhem, Håkan; Vago, Jorge; de Groot, Rolf; McCoy, Don

    2016-04-01

    ExoMars is a joint programme of the European Space Agency (ESA) and Roscosmos, Russia. It consists of the ExoMars 2016 mission with the Trace Gas Orbiter, TGO, and the Entry Descent and Landing Demonstrator, EDM, named Schiaparelli, and the ExoMars 2018 mission, which carries a lander and a rover. The TGO scientific payload consists of four instruments. These are: ACS and NOMAD, both infrared spectrometers for atmospheric measurements in solar occultation mode and in nadir mode, CASSIS, a multichannel camera with stereo imaging capability, and FREND, an epithermal neutron detector to search for subsurface hydrogen (as proxy for water ice and hydrated minerals). The mass of the TGO is 3700 kg, including fuel. The EDM, with a mass of 600 kg, is mounted on top of the TGO as seen in its launch configuration. The EDM is carried to Mars by the TGO and is separated three days before arrival at Mars. In addition to demonstrating the landing capability two scientific investigations are included with the EDM. The AMELIA investigation aims at characterising the Martian atmosphere during the entry and descent using technical and engineering sensors of the EDM, and the DREAMS suite of sensors that will characterise the environment of the landing site for a few days after the landing. ESA provides the TGO spacecraft and the Schiaparelli Lander demonstrator, ESA member states provide two of the TGO instruments and Roscosmos provides the launcher and the other two TGO instruments. After the arrival of the ExoMars 2018 mission at the surface of Mars, the TGO will handle all communications between the Earth and the Rover. The communication between TGO and the rover/lander is done through a UHF communications system, a contribution from NASA. The 2016 mission will be launched by a Russian Proton rocket from Baikonur in March 2016 (launch window 14-25 March) and will arrive at Mars on 19 October. This presentation will cover a description of the 2016 mission, including the spacecraft

  17. Exceptional results from, and status of, EXO-200

    Science.gov (United States)

    Smith, Erica; EXO-200 Collaboration

    2015-10-01

    EXO-200 has provided one of the most sensitive searches for neutrinoless double-beta decay utilizing 175 kg of enriched liquid xenon in an ultra-low background time projection chamber. This detector has demonstrated excellent energy resolution and background rejection capabilities. Using the first two years of data, EXO-200 has set a limit of 1 . 1 ×1025 y at 90% C.L. on the neutrinoless double-beta decay half-life of Xe136. The experiment has experienced a brief hiatus in data taking during a temporary shutdown of its host facility: the Waste Isolation Pilot Plant. EXO-200 expects to resume data taking in earnest this fall with upgraded detector electronics. Results from the analysis of EXO-200 data and an update on the current status of EXO-200 will be presented.

  18. Novel endo- to exo-isomerization of dicyclopentadiene

    Institute of Scientific and Technical Information of China (English)

    Xiang Wen Zhang; Kai Jiang; Qiang Jiang; Ji Jun Zou; Li Wang; Zhen Tao Mi

    2007-01-01

    Endo-dicyclopentadiene was isomerized to exo-isomer by thermal treatment at evaluated temperature and pressure.The reaction temperature and pressure are key factors for this novel isomerization.This result may have great potential for practical application.

  19. Characterization of Large Area APDs for the EXO-200 Detector

    Energy Technology Data Exchange (ETDEWEB)

    Neilson, R.; LePort, F.; Pocar, A.; /Stanford U., Phys. Dept.; Kumar, K.; /Massachusetts U., Amherst; Odian, A.; Prescott, C.Y.; /SLAC; Tenev, V.; /Stanford U., Phys. Dept.; Ackerman, N.; /SLAC; Akimov, D.; /Moscow, ITEP; Auger, M.; /Bern U., LHEP; Benitez-Medina, C.; /Colorado State U.; Breidenbach, M.; /SLAC; Burenkov, A.; /Moscow, ITEP; Conley, R.; /SLAC; Cook, S.; /Colorado State U.; deVoe, R.; Dolinski, M.J.; /Stanford U., Phys. Dept.; Fairbank, W., Jr.; /Colorado State U.; Farine, J.; /Laurentian U.; Fierlinger, P.; Flatt, B.; /Stanford U., Phys. Dept. /Bern U., LHEP /Stanford U., Phys. Dept. /Maryland U. /Colorado State U. /Laurentian U. /Carleton U. /SLAC /Maryland U. /Moscow, ITEP /Alabama U. /SLAC /Colorado State U. /Stanford U., Phys. Dept. /Alabama U. /Stanford U., Phys. Dept. /Alabama U. /SLAC /Carleton U. /SLAC /Maryland U. /Moscow, ITEP /Carleton U. /Stanford U., Phys. Dept. /Bern U., LHEP /SLAC /Laurentian U. /SLAC /Maryland U.

    2011-12-02

    EXO-200 uses 468 large area avalanche photodiodes (LAAPDs) for detection of scintillation light in an ultra-low-background liquid xenon (LXe) detector. We describe initial measurements of dark noise, gain and response to xenon scintillation light of LAAPDs at temperatures from room temperature to 169 K - the temperature of liquid xenon. We also describe the individual characterization of more than 800 LAAPDs for selective installation in the EXO-200 detector.

  20. A panoramic view of the ExoMars Project

    OpenAIRE

    Witasse, Olivier

    2014-01-01

    ExoMars is a cooperative programme between ESA and ROSCOSMOS, with NASA contributions. ExoMars includes two missions, one in 2016 and one in 2018, and is considered a necessary preparatory step for the future realisation of an international Mars Sample Return (MSR) mission during the second half of the next decade. The 2016 mission includes two elements: an orbiting satellite (Trace Gas Orbiter, TGO) devoted to the study of atmospheric trace gases and subsurface water, with the goal to acquir...

  1. Human exonuclease 1 (EXO1) activity characterization and its function on FLAP structures

    DEFF Research Database (Denmark)

    Keijzers, Guido; Bohr, Vilhelm A; Juel Rasmussen, Lene

    2015-01-01

    Human exonuclease 1 (EXO1) is involved in multiple DNA metabolism processes, including DNA repair and replication. Most of the fundamental roles of EXO1 have been described in yeast. Here, we report a biochemical characterization of human full-length EXO1. Prior to assay EXO1 on different DNA flap...... structures, we determined factors essential for the thermodynamic stability of EXO1. We show that enzymatic activity and stability of EXO1 on DNA is modulated by temperature. By characterization of EXO1 flap activity using various DNA flap substrates, we show that EXO1 has a strong capacity for degrading...... double stranded DNA and has a modest endonuclease or 5' flap activity. Furthermore, we report novel mechanistic insights into the processing of flap structures, showing that EXO1 preferentially cleaves one nucleotide inwards in a double stranded region of a forked and nicked DNA flap substrates...

  2. Absorption features in the spectra of X-ray bursting neutron stars

    CERN Document Server

    Rauch, Thomas; Werner, Klaus

    2008-01-01

    The discovery of photospheric absorption lines in XMM-Newton spectra of the X-ray bursting neutron star in EXO0748-676 by Cottam and collaborators allows us to constrain the neutron star mass-radius ratio from the measured gravitational redshift. A radius of R=9-12km for a plausible mass range of M=1.4-1.8Msun was derived by these authors. It has been claimed that the absorption features stem from gravitationally redshifted (z=0.35) n=2-3 lines of H- and He-like iron. We investigate this identification and search for alternatives. We compute LTE and non-LTE neutron-star model atmospheres and detailed synthetic spectra for a wide range of effective temperatures (effective temperatures of 1 - 20MK) and different chemical compositions. We are unable to confirm the identification of the absorption features in the X-ray spectrum of EXO0748-676 as n=2-3 lines of H- and He-like iron (Fe XXVI and Fe XXV). These are subordinate lines that are predicted by our models to be too weak at any effective temperature. It is m...

  3. ExoData: A python package to handle large exoplanet catalogue data

    CERN Document Server

    Varley, Ryan

    2015-01-01

    Exoplanet science often involves using the system parameters of real exoplanets for tasks such as simulations, fitting routines, and target selection for proposals. Software that bridges the barrier between the catalogues and code enables users to improve the specific repeatability of results by facilitating the retrieval of exact system parameters used in an articles results along with unifying the equations and software used. As exoplanet science moves towards large data, gone are the days where researchers can recall the current population from memory. An interface able to query the population now becomes invaluable for target selection and population analysis. ExoData is a python interface and exploratory analysis tool for the Open Exoplanet Catalogue. It allows the loading of exoplanet systems into python as objects (Planet, Star, Binary etc) from which common orbital and system equations can be calculated and measured parameters retrieved. This allows researchers to use tested code of the common equatio...

  4. Calibration Binaries

    Science.gov (United States)

    Drummond, J.

    2011-09-01

    Two Excel Spreadsheet files are offered to help calibrate telescope or camera image scale and orientation with binary stars for any time. One is a personally selected list of fixed position binaries and binaries with well-determined orbits, and the other contains all binaries with published orbits. Both are derived from the web site of the Washington Double Star Library. The spreadsheets give the position angle and separation of the binaries for any entered time by taking advantage of Excel's built in iteration function to solve Kepler's transcendental equation.

  5. The EXO-200 detector, part I: Detector design and construction

    CERN Document Server

    Auger, M; Barbeau, P S; Bartoszek, L; Baussan, E; Beauchamp, E; Benitez-Medina, C; Breidenbach, M; Chauhan, D; Cleveland, B; Conley, R; Cook, J; Cook, S; Coppens, A; Craddock, W; Daniels, T; Davis, C G; Davis, J; deVoe, R; Dobi, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Fierlinger, P; Franco, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Hagemann, C; Hall, C; Hall, K; Hargrove, C; Herrin, S; Hodgson, J; Hughes, M; Karelin, A; Kaufman, L J; Kirk, J; Kuchenkov, A; Kumar, K; Leonard, D S; Leonard, F; LePort, F; Mackay, D; MacLellan, R; Marino, M; Merkle, K; Mong, B; Díez, M Montero; Müller, A R; Neilson, R; Odian, A; O'Sullivan, K; Oullet, C; Piepke, A; Pocar, A; Prescott, C Y; Pushkin, K; Rivas, A; Rollin, E; Rowson, P C; Sabourov, A; Sinclair, D; Skarpaas, K; Slutsky, S; Stekhanov, V; Strickland, V; Swift, M; Tosi, D; Twelker, K; Vuilleumier, J -L; Vuilleumier, J -M; Walton, T; Weber, M; Wichoski, U; Wodin, J; Wright, J D; Yang, L; Yen, Y -R

    2012-01-01

    EXO-200 is an experiment designed to search for double beta decay of $^{136}$Xe with a single-phase, liquid xenon detector. It uses an active mass of 110 kg of xenon enriched to 80.6% in the isotope 136 in an ultra-low background time projection chamber capable of simultaneous detection of ionization and scintillation. This paper describes the EXO-200 detector with particular attention to the most innovative aspects of the design that revolves around the reduction of backgrounds, the efficient use of the expensive isotopically enriched xenon, and the optimization of the energy resolution in a relatively large volume.

  6. Interacting binaries

    CERN Document Server

    Shore, S N; van den Heuvel, EPJ

    1994-01-01

    This volume contains lecture notes presented at the 22nd Advanced Course of the Swiss Society for Astrophysics and Astronomy. The contributors deal with symbiotic stars, cataclysmic variables, massive binaries and X-ray binaries, in an attempt to provide a better understanding of stellar evolution.

  7. The Enriched Xenon Observatory (EXO) for double beta decay

    International Nuclear Information System (INIS)

    The Enriched Xenon Observatory (EXO) is an experimental program designed to search for the neutrinoless double beta decay (0νββ) of Xe-136. of 0nbb would determine an absolute mass scale for neutrinos and answer the question about their Majorana nature. The current phase of the experiment, EXO-200, uses 200 kg of liquid xenon with 80% enrichment in Xe-136. The double beta decay of xenon is detected in an ultra-low background time projection chamber by collecting both, the scintillation light and the ionization charge. The detector has provided the first measurement of two neutrino double beta decay and continues to take data for a neutrinoless analysis.

  8. Continuing the Operation of EXO-200 at WIPP

    Energy Technology Data Exchange (ETDEWEB)

    Gratta, Giorgio [Stanford Univ., CA (United States)

    2016-02-24

    This grant supported, in part, the operations of the EXO-200 double beta decay experiment at the Waste Isolation Pilot Plant (WIPP) for the period May 1, 2013 to Sept 30, 2015. In this period EXO-200 completed its first phase of data taking, although its operation was disrupted in Feb 2014 by the accidents at WIPP (unrelated to the experiment). The primary goal of the experiment is to search for the very rate (and to date not observed) neutrino-less double beta decay. Such decay, if observed, would shed the light of the quantum-mechanical structure of neutrinos, and the origins of elementary particle masses. Another goal of the detector is to serve as prototype of a larger neutrino-less double beta decay experiment, currently being considered by DOE-OS.

  9. ExoPriors: Accounting for observational bias of transiting exoplanets

    Science.gov (United States)

    Kipping, David M.; Sandford, Emily

    2016-03-01

    ExoPriors calculates a log-likelihood penalty for an input set of transit parameters to account for observational bias (geometric and signal-to-noise ratio detection bias) of transiting exoplanets. Written in Python, the code calculates this log-likelihood penalty in one of seven user-specified cases specified with Boolean input parameters for geometric and/or SNR bias, grazing or non-grazing events, and occultation events.

  10. ExoMars entry, descent and landing science

    OpenAIRE

    Ferri, F; Lewis, S R; Withers, P.; Aboudan, A.; Bettanini, C.; Colombatti, G.; Debei, S.; Golombek, M.; Harri, A. M.; Komatsu, G.; Leese, M. R.; T. Mäkinen; Müller-Wodarg, I.; Ori, G. G.; M. R. Patel

    2011-01-01

    The entry, descent and landing of ExoMars offer a rare (once-per-mission) opportunity to perform in situ investigation of the martian environment over a wide altitude range. Entry, Descent and Landing System (EDLS) measurements can provide essential data for atmospheric scientific investigations. We intend to perform atmospheric science measurements by exploiting data from EDLS engineering sensors and exploiting their readings beyond the expected engineering information.

  11. Evidence Contrary to the Existing Exo-Planet Migration Concept

    CERN Document Server

    Herndon, J M

    2006-01-01

    Exo-planet migration is assumed to have occurred to explain close-to-star gas giant exo-planets within the context of the so-called standard model of solar system formation, rather than giving cause to question the validity of that particular model. I present evidence against the concept of planet migration, evidence that is historical, interdisciplinary, and model-independent. First, I demonstrate a flaw in the standard model of solar system formation that would lead to the contradiction of terrestrial planets having insufficiently massive cores. Then, I discuss the evidence that points to the Earth previously having been a Jupiter-like close-to-Sun gas giant and the consequences that arise there from. Observations of close-to-star gas giant exo-planets orbiting stars other than our own Sun, rather than being evidence for planet migration, I submit, are evidence for differing degrees of violence associated with the thermonuclear ignition of their particular stars. As observational resolution improves, one mi...

  12. Comparative characterization of three bacterial exo-type alginate lyases.

    Science.gov (United States)

    Hirayama, Makoto; Hashimoto, Wataru; Murata, Kousaku; Kawai, Shigeyuki

    2016-05-01

    Alginate, a major acidic polysaccharide in brown macroalgae, has attracted attention as a carbon source for production of ethanol and other chemical compounds. Alginate is monomerized by exo-type alginate lyase into an unsaturated uronate; thus, this enzyme is critical for the saccharification and utilization of alginate. Although several exo-type alginate lyases have been characterized independently, their activities were not assayed under the same conditions or using the same unit definition, making it difficult to compare enzymatic properties or to select the most suitable enzyme for saccharification of alginate. In this study, we characterized the three bacterial exo-type alginate lyases under the same conditions: A1-IV of Sphingomonas sp. strain A1, Atu3025 of Agrobacterium tumefaciens, and Alg17c of Saccharophagus degradans. A1-IV had the highest specific activity as well as the highest productivity of uronate, whereas Alg17c had the lowest activity and productivity. Only dialyzed Atu3025 and Alg17c were tolerant to freezing. Alg17c exhibited a remarkable halotolerance, which may be advantageous for monomerization of alginate from marine brown algae. Thus, each enzyme exhibited particular desirable and undesirable properties. Our results should facilitate further utilization of the promising polysaccharide alginate. PMID:26827758

  13. Systematic Study of Trace Radioactive Impurities in Candidate Construction Materials for EXO-200

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, D.S.; Grinberg, P.; Weber, P.; Baussan, E.; Djurcic, Z.; Keefer, G.; Piepke, A.; Pocar, A.; Vuilleumier, J.-L.; Vuilleumier, J.-M.; Akimov, D.; Bellerive, A.; Bowcock, M.; Breidenbach, M.; Burenkov, A.; Conley, R.; Craddock, W.; Danilov, M.; DeVoe, R.; Dixit, M.; Dolgolenko, A.; /Alabama U. /NRC-INMS /Neuchatel U. /Stanford U., Phys. Dept. /SLAC /Colorado State U. /Laurentian U. /Maryland U. /UC, Irvine

    2007-10-24

    The Enriched Xenon Observatory (EXO) will search for double beta decays of 136Xe. We report the results of a systematic study of trace concentrations of radioactive impurities in a wide range of raw materials and finished parts considered for use in the construction of EXO-200, the first stage of the EXO experimental program. Analysis techniques employed, and described here, include direct gamma counting, alpha counting, neutron activation analysis, and high-sensitivity mass spectrometry.

  14. Systematic study of trace radioactive impurities in candidate construction materials for EXO-200

    CERN Document Server

    Leonard, D S; Weber, P; Baussan, E; Djurcic, Z; Keefer, G; Piepke, A; Pocar, A; Vuilleumier, J -L; Vuilleumier, J -M; Akimov, D; Bellerive, A; Bowcock, M; Breidenbach, M; Burenkov, A; Conley, R; Craddock, W; Danilov, M; DeVoe, R; Dixit, M; Dolgolenko, A; Ekchtout, I; Fairbank, W; Farine, J; Fierlinger, P; Flatt, B; Gratta, G; Green, M; Hall, C; Hall, K; Hallman, D; Hargrove, C; Herbst, R; Hodgson, J; Jeng, S; Kolkowitz, S; Kovalenko, A; Kovalenko, D; LePort, F; Mackay, D; Moe, M; Díez, M Montero; Neilson, R; Odian, A; O'Sullivan, K; Ounalli, L; Prescott, C Y; Rowson, P C; Schenker, D; Sinclair, D; Skarpaas, K; Smirnov, G; Stekhanov, V; Strickland, V; Virtue, C; Wamba, K; Wodin, J

    2007-01-01

    The Enriched Xenon Observatory (EXO) will search for double beta decays of 136Xe. We report the results of a systematic study of trace concentrations of radioactive impurities in a wide range of raw materials and finished parts considered for use in the construction of EXO-200, the first stage of the EXO experimental program. Analysis techniques employed, and described here, include direct gamma counting, alpha counting, neutron activation analysis, and high-sensitivity mass spectrometry.

  15. ESA ExoMars: Pre-launch PanCam Geometric Modeling and Accuracy Assessment

    OpenAIRE

    Li, D.; Li, R; Yilmaz, A.

    2014-01-01

    ExoMars is the flagship mission of the European Space Agency (ESA) Aurora Programme. The mobile scientific platform, or rover, will carry a drill and a suite of instruments dedicated to exobiology and geochemistry research. As the ExoMars rover is designed to travel kilometres over the Martian surface, high-precision rover localization and topographic mapping will be critical for traverse path planning and safe planetary surface operations. For such purposes, the ExoMars rover Panora...

  16. ExoMars: Planetary Protection Status and Update

    Science.gov (United States)

    Guarnieri, Vincenzo

    The ExoMars Program will demonstrate key flight and in situ enabling technologies in support of the European ambitions for future exploration missions, as outlined in the Aurora Decla-ration and will pursue fundamental scientific investigations. Two missions are foreseen within the ExoMars program for 2016 and 2018 launch opportunities to Mars: 2016 mission with ESA Orbiter Module (OM) providing communication with the Earth and carrying NASA scientific instruments and the ESA Entry, Descent and Landing Demonstrator (EDM, 600kg); NASA lead 2018 mission with an ESA Rover Module (RM, 300 kg) accommodated in the Sky Crane together with NASA rover. The EDM will test the Entry, Descent and Landing of a payload on the surface of Mars. The ESA RM will travel several kilometers performing environmental investigations and looking for traces of past and present life signs, by collecting and analyzing samples from within surface rocks and from the subsurface. The planetary protection pol-icy of the Committee on Space Research (COSPAR) and the particular sensitivity of the life detection investigations establish stringent contamination control constraints for the two Exo-Mars missions. Particulate, molecular and bioburden contamination control beyond the level of standard spacecraft is required for the flight system as well as for the assembly, test, and launch environment. The ExoMars mission can be classified as Planetary Protection Category III for the OM and Category IVa for the EDM in 2016. The Rover Module in 2018 is part of a Category IVb mission. Main scientific objective of the 2018 mission is searching for traces of past or extant life in terms of amino acids and other organic molecules by using on board instruments characterized by an extremely high sensitivity. This mission would hence permit a great improvement of the knowledge about the Red Planet environment and the identification of possible surface hazards for future human exploration missions. During the

  17. Binary Planets

    Science.gov (United States)

    Ryan, Keegan; Nakajima, Miki; Stevenson, David J.

    2014-11-01

    Can a bound pair of similar mass terrestrial planets exist? We are interested here in bodies with a mass ratio of ~ 3:1 or less (so Pluto/Charon or Earth/Moon do not qualify) and we do not regard the absence of any such discoveries in the Kepler data set to be significant since the tidal decay and merger of a close binary is prohibitively fast well inside of 1AU. SPH simulations of equal mass “Earths” were carried out to seek an answer to this question, assuming encounters that were only slightly more energetic than parabolic (zero energy). We were interested in whether the collision or near collision of two similar mass bodies would lead to a binary in which the two bodies remain largely intact, effectively a tidal capture hypothesis though with the tidal distortion being very large. Necessarily, the angular momentum of such an encounter will lead to bodies separated by only a few planetary radii if capture occurs. Consistent with previous work, mostly by Canup, we find that most impacts are disruptive, leading to a dominant mass body surrounded by a disk from which a secondary forms whose mass is small compared to the primary, hence not a binary planet by our adopted definition. However, larger impact parameter “kissing” collisions were found to produce binaries because the dissipation upon first encounter was sufficient to provide a bound orbit that was then rung down by tides to an end state where the planets are only a few planetary radii apart. The long computational times for these simulation make it difficult to fully map the phase space of encounters for which this outcome is likely but the indications are that the probability is not vanishingly small and since planetary encounters are a plausible part of planet formation, we expect binary planets to exist and be a non-negligible fraction of the larger orbital radius exoplanets awaiting discovery.

  18. The ExoMars Entry & Descent system: an enabler for European planetary science

    Science.gov (United States)

    Lebleu, D.; Monier, J.; Marchand, B.; Squillaci, J.-R.; Lubrano, G.; Capus, P.; Laurenti, P.; Poncy, J.; Couzin, P.

    2013-09-01

    After HUYGENS and thanks to the ExoMars Entry and Descent System, Europe will confirm the capacity to land on planetary bodies. This presentation reports the development status of ExoMars EDM Entry & Descent system. All development tests are performed, and the subsystems flight models manufacturing are in progress.

  19. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices...

  20. EXO the Enriched Xenon Observatory for Double Beta Decay

    CERN Document Server

    Wamba, K

    2002-01-01

    EXO is a search for neutrinoless double beta decay in 136Xe. An active R&D program for a 10 ton, enriched 136Xe liquid phase detector is now underway. Current research projects are: decay product extraction, Xe purity studies, energy resolution studies, and Ba+ ion laser-tagging. By extracting and laser-tagging the Xe decay product (136Ba) and optimizing the energy resolution in liquid Xe, half lives of up to 5.0x10^28yr will be ultimately probed, corresponding to a sensitivity to Majorana n masses > ~10meV.

  1. Probing Mars’ atmosphere with ExoMars Mars Climate Sounder

    OpenAIRE

    Irwin, Patrick G. J.; Calcutt, S.B.; P. L. Read; Bowles, N E; Lewis, S

    2011-01-01

    The 2016 Mars Trace Gas Mission will carry with it the ExoMars Mars Climate Sounder instrument, a development of the very successful Mars Climate Sounder instrument already in orbit about Mars on NASA's Mars Reconnaissance Orbiter spacecraft. EMCS will continue the monitoring of Mars global temperature/pressure/aerosol field, and will also be able to measure the vertical profile of water vapour across the planet from 0 – 50 km. Key components of EMCS will be provided by Oxford, Reading and Ca...

  2. Using Intermediate-Luminosity Optical Transients (ILOTs) to reveal extended exo-solar Kuiper belt objects

    CERN Document Server

    Bear, Ealeal

    2016-01-01

    We suggest that in the rare case of an Intermediate-Luminosity Optical Transient (ILOTs) event, evaporation of exo-solar Kuiper belt objects (ExoKBOs) at distances of d~500 - 10000AU from the ILOT can be detected. If the ILOT lasts for 1 month to a few years, enough dust might be ejected from the ExoKBOs for the IR emission to be detected. Because of the large distance of the ExoKBOs, tens of years will pass before the ILOT wind disperses the dust. We suggest that after an ILOT outburst there is a period of months to several years during which IR excess emission might hint at the existence of a Kuiper belt analog (ExoK-Belt).

  3. Exo70 Isoform Switching upon Epithelial-Mesenchymal Transition Mediates Cancer Cell Invasion

    Science.gov (United States)

    Lu, Hezhe; Liu, Jianglan; Liu, Shujing; Zeng, Jingwen; Ding, Deqiang; Carstens, Russ P.; Cong, Yusheng; Xu, Xiaowei; Guo, Wei

    2014-01-01

    Summary Epithelial-mesenchymal transition (EMT) is an important developmental process hijacked by cancer cells for their dissemination. Here we show that Exo70, a component of the exocyst complex, undergoes isoform switching mediated by ESRP1, a pre-mRNA splicing factor that regulates EMT. Expression of the epithelial isoform of Exo70 affects the levels of key EMT transcriptional regulators such as Snail and ZEB2, and is sufficient to drive the transition to epithelial phenotypes. Differential Exo70 isoforms expression in human tumors correlates with cancer progression, and increased expression of the epithelial isoform of Exo70 inhibits tumor metastasis in mice. At the molecular level, the mesenchymal but not the epithelial isoform of Exo70 interacts with the Arp2/3 complex and stimulates actin polymerization for tumor invasion. Our findings provide a mechanism by which the exocyst function and actin dynamics are modulated for EMT and tumor invasion. PMID:24331928

  4. The Be X-ray Binary Outburst Zoo II

    Science.gov (United States)

    Kuehnel, M.; Kretschmar, P.; Nespoli, E.; Okazaki, A. T.; Schoenherr, G.; Wilson-Hodge, C. A.; Falkner, S.; Brand, T.; Anders, F.; Schwarm, F.-W.; Kreykenbohm, I.; Mueller, S.; Pottschmidt, K.; Fuerst, F.; Grinberg, V.; Wilms, J.

    2015-03-01

    We have continued our recently started systematic study of Be X-ray binary (BeXRB) outbursts. Specifically, we are developing a catalogue of outbursts including their basic properties based on nearly all available X-ray all-sky-monitors. These properties are derived by fitting asymmetric Gaussians to the outburst lightcurves. This model describes most of the outbursts covered by our preliminary catalogue well; only 13% of all datasets show more complex outburst shapes. Analyzing the basic properties, we reveal a strong correlation between the outburst length and the reached peak flux. As an example, we discuss possible models describing the observed correlation in EXO 2030+375.

  5. EXO70基因在甘蓝和白菜基因组中的倍增与趋异进化%EXO70 gene duplication and divergent evolution in Brassica oleracea and B.rapa

    Institute of Scientific and Technical Information of China (English)

    杨昆; 吕俊; 张毅; 赵永斌; 张贺翠; 韩叙; 许军红; 卢会翔; 施松梅

    2015-01-01

    为探明EXO70基因在白菜和甘蓝基因组中的倍增,从BRAD数据库中分别搜索并鉴定出39和45种不同的EXO70基因.分析发现,同种EXO70及其编码基因在白菜和甘蓝中极度保守,不同类型EXO70的氨基酸组成存在差异,pfam03081是每个EXO70蛋白所共有;不同EXO70基因的外显子数目差异明显,尤以EXO70A的外显子数目最多;BoEXO70在进化过程中发生了较BrEXO70程度更高的DNA丢失情况;白菜和甘蓝EXO70基因总的密码子偏性近乎相同,而不同类EXO70基因之间的密码子使用却出现程度不同的差异.得出推论,尽管EXO70基因在两物种中拥有近乎相同的倍增模式,它在甘蓝中的倍增程度高于白菜;同种类型的EXO70基因在白菜和甘蓝中高度保守,pfam03081是决定EXO70蛋白功能的关键因素;EXO70基因在两个物种内的倍增表现出趋异的进化.

  6. EXO-ZODI MODELING FOR THE LARGE BINOCULAR TELESCOPE INTERFEROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Grant M.; Wyatt, Mark C.; Panić, Olja; Shannon, Andrew [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Bailey, Vanessa; Defrère, Denis; Hinz, Philip M.; Rieke, George H.; Skemer, Andrew J.; Su, Katherine Y. L. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bryden, Geoffrey; Mennesson, Bertrand; Morales, Farisa; Serabyn, Eugene [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Danchi, William C.; Roberge, Aki; Stapelfeldt, Karl R. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States); Haniff, Chris [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Lebreton, Jérémy [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Millan-Gabet, Rafael [NASA Exoplanet Science Institute, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); and others

    2015-02-01

    Habitable zone dust levels are a key unknown that must be understood to ensure the success of future space missions to image Earth analogs around nearby stars. Current detection limits are several orders of magnitude above the level of the solar system's zodiacal cloud, so characterization of the brightness distribution of exo-zodi down to much fainter levels is needed. To this end, the Large Binocular Telescope Interferometer (LBTI) will detect thermal emission from habitable zone exo-zodi a few times brighter than solar system levels. Here we present a modeling framework for interpreting LBTI observations, which yields dust levels from detections and upper limits that are then converted into predictions and upper limits for the scattered light surface brightness. We apply this model to the HOSTS survey sample of nearby stars; assuming a null depth uncertainty of 10{sup –4} the LBTI will be sensitive to dust a few times above the solar system level around Sun-like stars, and to even lower dust levels for more massive stars.

  7. ExoMeg1: a new exonuclease from metagenomic library

    Science.gov (United States)

    Silva-Portela, Rita C. B.; Carvalho, Fabíola M.; Pereira, Carolina P. M.; de Souza-Pinto, Nadja C.; Modesti, Mauro; Fuchs, Robert P.; Agnez-Lima, Lucymara F.

    2016-01-01

    DNA repair mechanisms are responsible for maintaining the integrity of DNA and are essential to life. However, our knowledge of DNA repair mechanisms is based on model organisms such as Escherichia coli, and little is known about free living and uncultured microorganisms. In this study, a functional screening was applied in a metagenomic library with the goal of discovering new genes involved in the maintenance of genomic integrity. One clone was identified and the sequence analysis showed an open reading frame homolog to a hypothetical protein annotated as a member of the Exo_Endo_Phos superfamily. This novel enzyme shows 3′-5′ exonuclease activity on single and double strand DNA substrates and it is divalent metal-dependent, EDTA-sensitive and salt resistant. The clone carrying the hypothetical ORF was able to complement strains deficient in recombination or base excision repair, suggesting that the new enzyme may be acting on the repair of single strand breaks with 3′ blockers, which are substrates for these repair pathways. Because this is the first report of an enzyme obtained from a metagenomic approach showing exonuclease activity, it was named ExoMeg1. The metagenomic approach has proved to be a useful tool for identifying new genes of uncultured microorganisms. PMID:26815639

  8. EXO-ZODI MODELING FOR THE LARGE BINOCULAR TELESCOPE INTERFEROMETER

    International Nuclear Information System (INIS)

    Habitable zone dust levels are a key unknown that must be understood to ensure the success of future space missions to image Earth analogs around nearby stars. Current detection limits are several orders of magnitude above the level of the solar system's zodiacal cloud, so characterization of the brightness distribution of exo-zodi down to much fainter levels is needed. To this end, the Large Binocular Telescope Interferometer (LBTI) will detect thermal emission from habitable zone exo-zodi a few times brighter than solar system levels. Here we present a modeling framework for interpreting LBTI observations, which yields dust levels from detections and upper limits that are then converted into predictions and upper limits for the scattered light surface brightness. We apply this model to the HOSTS survey sample of nearby stars; assuming a null depth uncertainty of 10–4 the LBTI will be sensitive to dust a few times above the solar system level around Sun-like stars, and to even lower dust levels for more massive stars

  9. ExoMars 2018: the four final candidate Landing Sites

    Science.gov (United States)

    Loizeau, Damien; Flahaut, Jessica; Vago, Jorge L.; Hauber, Ernst; Bridges, John C.

    2015-04-01

    The ExoMars 2018 mission will land a rover on Mars, its scientific objectives are to search for signs of past and present life on Mars and to investigate the water/geochemical environment as a function of depth in the shallow subsurface. The rover will be able to travel several kilometres, analyzing surface and subsurface samples, down to a 2 meter depth. The very powerful combination of mobility with the ability to access in-depth locations, where organic molecules can be well preserved, is unique to this mission [1]. An invitation has been sent to the community to propose scientifically compelling sites for the mission [2], which comply to the main engineering constraints for landing and operation safety. Scientifically interesting sites include locations with evidence for long duration or frequently recurring aqueous activity, low energy transport and deposition, fined-grained, recently exposed sediments, and/or hydrated minerals such as clays or evaporites. The outcrops of interest must be distributed over the landing ellipse to ensure that the rover can access some of them over a short distance [2]. The received proposals have been reviewed by the Landing Site Selection Working Group (LSSWG) and at first eight sites were found to be compliant with the science, engineering, and planetary protection requirements [3]. These sites were presented by their proposers and discussed at the first landing site workshop that took place in ESAC, Spain, 26-28 March 2014. Following that workshop, four sites were selected for further investigation, on the base of their higher potential for long lived water activity, the presence of fine grained sediments, and also importantly on the high concentration of potential targets of interest over the whole landing ellipse [3]. The analysis of these sites, both in term of scientific relevance and engineering safety, is still on-going. Latest findings were presented during a second workshop that took place in ALTEC, Torino, Italy, 11

  10. Exocyst subunits Exo70 and Exo84 cooperate with small GTPases to regulate behavior and endocytic trafficking in C. elegans.

    Directory of Open Access Journals (Sweden)

    Yaming Jiu

    Full Text Available The exocyst complex is required for cell polarity regulation and the targeting and tethering of transport vesicles to the plasma membrane. The complex is structurally well conserved, however, the functions of individual subunits and their regulation is poorly understood. Here we characterize the mutant phenotypes for the exocyst complex genes exoc-7 (exo70 and exoc-8 (exo84 in Caenorhabditis elegans. The mutants display pleiotropic behavior defects that resemble those observed in cilia mutants (slow growth, uncoordinated movement, defects in chemo-, mechano- and thermosensation. However, no obvious morphological defects in cilia were observed. A targeted RNAi screen for small GTPases identified eleven genes with enhanced phenotypes when combined with exoc-7, exoc-8 single and exoc-7;exoc-8 double mutants. The screen verified previously identified functional links between the exocyst complex and small GTPases and, in addition, identified several novel potential regulators of exocyst function. The exoc-8 and exoc-7;exoc-8 mutations caused a significant size increase in the rab-10 RNAi-induced endocytic vacuoles in the intestinal epithelial cells. In addition, exoc-8 and exoc-7;exoc-8 mutations resulted in up-regulation of RAB-10 expression and affected the accumulation of endocytic marker proteins in these cells in response to rab-10 RNAi. The findings identify novel, potential regulators for exocyst function and show that exoc-7 and exoc-8 are functionally linked to rab-10 in endosomal trafficking in intestinal epithelial cells in C. elegans.

  11. Maximizing the ExoEarth candidate yield from a future direct imaging mission

    Energy Technology Data Exchange (ETDEWEB)

    Stark, Christopher C. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Roberge, Aki; Mandell, Avi [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Robinson, Tyler D., E-mail: christopher.c.stark@nasa.gov [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2014-11-10

    ExoEarth yield is a critical science metric for future exoplanet imaging missions. Here we estimate exoEarth candidate yield using single visit completeness for a variety of mission design and astrophysical parameters. We review the methods used in previous yield calculations and show that the method choice can significantly impact yield estimates as well as how the yield responds to mission parameters. We introduce a method, called Altruistic Yield Optimization, that optimizes the target list and exposure times to maximize mission yield, adapts maximally to changes in mission parameters, and increases exoEarth candidate yield by up to 100% compared to previous methods. We use Altruistic Yield Optimization to estimate exoEarth candidate yield for a large suite of mission and astrophysical parameters using single visit completeness. We find that exoEarth candidate yield is most sensitive to telescope diameter, followed by coronagraph inner working angle, followed by coronagraph contrast, and finally coronagraph contrast noise floor. We find a surprisingly weak dependence of exoEarth candidate yield on exozodi level. Additionally, we provide a quantitative approach to defining a yield goal for future exoEarth-imaging missions.

  12. Nuclear localization of human DNA mismatch repair protein exonuclease 1 (hEXO1)

    DEFF Research Database (Denmark)

    Knudsen, Nina Østergaard; Nielsen, Finn Cilius; Vinther, Lena;

    2007-01-01

    localization signals (NLSs) in hEXO1. Using fluorescent fusion proteins, we show that the sequence 418KRPR421, which exhibit strong homology to other monopartite NLS sequences, is responsible for correct nuclear localization of hEXO1. This NLS sequence is located in a region that is also required for hEXO1......Human exonuclease 1 (hEXO1) is implicated in DNA mismatch repair (MMR) and mutations in hEXO1 may be associated with hereditary nonpolyposis colorectal cancer (HNPCC). Since the subcellular localization of MMR proteins is essential for proper MMR function, we characterized possible nuclear...... interaction with hMLH1 and we show that defective nuclear localization of hEXO1 mutant proteins could be rescued by hMLH1 or hMSH2. Both hEXO1 and hMLH1 form complexes with the nuclear import factors importin beta/alpha1,3,7 whereas hMSH2 specifically recognizes importin beta/alpha3. Taken together, we infer...

  13. Production of exo-pectinase by Penicillium roqueorti using pumpkin oil cake

    OpenAIRE

    Peričin Draginja M.; Mađarev Senka Z.; Radulović Lj.M.; Škrinjar Marija M.

    2007-01-01

    Submerged fermentation (SmF) was carried out using the pumpkin oil cake (PuOC) as a substrate for the production of exo-pectinase (exo-p) by Penicillium roqueforti. PuOC was used as carbon, nitrogen and mineral source for fungi growth and exo-p production. SmF was carried out in the production medium containing 0.2% KH2PO4, 0.1% MgSO4 and 0.1% NaCl, supplemented with PuOC at 2% concentration. The obtained results show that P. roqueforti cultivated in a liquid medium in the presence of PuOC as...

  14. Maximized ExoEarth Candidate Yields for Starshades

    CERN Document Server

    Stark, Christopher C; Lisman, Doug; Cady, Eric; Savransky, Dmitry; Roberge, Aki; Mandell, Avi M

    2016-01-01

    The design and scale of a future mission to directly image and characterize potentially Earth-like planets will be impacted, to some degree, by the expected yield of such planets. Recent efforts to increase the estimated yields, by creating observation plans optimized for the detection and characterization of Earth-twins, have focused solely on coronagraphic instruments; starshade-based missions could benefit from a similar analysis. Here we explore how to prioritize observations for a starshade given the limiting resources of both fuel and time, present analytic expressions to estimate fuel use, and provide efficient numerical techniques for maximizing the yield of starshades. We implemented these techniques to create an approximate design reference mission code for starshades and used this code to investigate how exoEarth candidate yield responds to changes in mission, instrument, and astrophysical parameters for missions with a single starshade. We find that a starshade mission operates most efficiently so...

  15. Structural Evaluation of Exo-Skeletal Engine Fan Blades

    Science.gov (United States)

    Kuguoglu, Latife; Abumeri, Galib; Chamis, Christos C.

    2003-01-01

    The available computational simulation capability is used to demonstrate the structural viability of composite fan blades of innovative Exo-Skeletal Engine (ESE) developed at NASA Glenn Research Center for a subsonic mission. Full structural analysis and progressive damage evaluation of ESE composite fan blade is conducted through the NASA in-house computational simulation software system EST/BEST. The results of structural assessment indicate that longitudinal stresses acting on the blade are in compression. At a design speed of 2000 rpm, pressure and suction surface outer most ply stresses in longitudinal, transverse and shear direction are much lower than the corresponding composite ply strengths. Damage is initiated at 4870 rpm and blade fracture takes place at rotor speed of 7735 rpm. Damage volume is 51 percent. The progressive damage, buckling, stress and strength results indicate that the design at hand is very sound because of the factor of safety, damage tolerance, and buckling load of 6811 rpm.

  16. Exo-C: Mission and Science Payload Design

    Science.gov (United States)

    Dekens, Frank G.; Stapelfeldt, Karl R.; Warfield, Keith; Unwin, Stephen C.; Exo-C Science; Technology Definition Team, Exo-C JPL Study Design Team

    2015-01-01

    We present NASA's Exoplanet Coronagraph (Exo-C) mission design and science payload completed as part of a probe-class concept study under consideration for launch following JWST. The payload consists of an unobscured Cassegrain telescope with a 1.4-m clear aperture, a barrel assembly, and an internal coronagraph instrument. The mission has a 3 year lifetime and is in a highly stable Earth-trailing orbit. The coronagraph instrument is mounted laterally on the anti-Sun side of the telescope, obviating the need for high incidence reflections and better isolating it from spacecraft disturbances. The instrument has both an Imaging Camera and an Integral Field Spectrograph (IFS). The former obtains filter imaging with 1e-9 raw contrast from 2 - 20 λ/D in radius, while the IFS delivers the same contrast with spectral resolution of R = 70 from 450 to 1000 nm, but with a reduced outer working angle.The Exo-C science performance requirements are achieved with a specialized observatory design enabled by several new technologies. The telescope is designed for precision pointing and high stability to maintain a slowly evolving speckle pattern. Vibration isolation is achieved with two stages between the reaction wheels and the science payload. The solar arrays and high gain antenna are body-fixed, and a stiff barrel assembly is used as the telescope metering structure. Telescope pointing is updated at a high rate by monitoring the bright science target star with a low order wavefront sensor and driving a fine steering mirror for compensation. Active thermal control is used to minimize thermal drifts of the telescope, instrument, and barrel assemblies. Stability analyses via modeling of the structural, thermal, and optical performance of this configuration show that the proposed mission configuration would enable unprecedented exoplanet and circumstellar disk science with direct imaging.

  17. Characterization of an exo-inulinase from Arthrobacter: a novel NaCl-tolerant exo-inulinase with high molecular mass.

    Science.gov (United States)

    Shen, Jidong; Zhang, Rui; Li, Junjun; Tang, Xianghua; Li, Ruixian; Wang, Min; Huang, Zunxi; Zhou, Junpei

    2015-01-01

    A glycoside hydrolase family 32 exo-inulinase gene was cloned from Arthrobacter sp. HJ7 isolated from saline soil located in Heijing town. The gene encodes an 892-residue polypeptide with a calculated mass of 95.1 kDa and a high total frequency of amino acid residues G, A, and V (30.0%). Escherichia coli BL21 (DE3) cells were used as hosts to express the exo-inulinase gene. The recombinant exo-inulinase (rInuAHJ7) showed an apparently maximal activity at pH 5.0-5.5 and 40-45°C. The addition of 1.0 and 10.0 mM Zn(2+) and Pb(2+) had little or no effect on the enzyme activity. rInuAHJ7 exhibited good salt tolerance, retaining more than 98% inulinase activity at a concentration of 3.0%-20.0% (w/v) NaCl. Fructose was the main product of inulin, levan, and Jerusalem artichoke tubers hydrolyzed by the enzyme. The present study is the first to report the identification and characterization of an Arthrobacter sp exo-inulinase showing a high molecular mass of 95.1 kDa and NaCl tolerance. These results suggest that the exo-inulinase might be an alternative material for potential applications in processing seafood and other foods with high saline contents, such as marine algae, pickles, and sauces. PMID:25695343

  18. Applicability of Supercritical CO2 Speleogenesis to Exo-Planetary Karst Systems

    Science.gov (United States)

    Decker, D. D.; Polyak, V. J.; Asmerom, Y.

    2015-10-01

    Supercritical CO2 hypogene speleogenesis and its applications to exo-planetary karst features are discussed. What to look for on the planet's surface to find these types of caves and their possible use is also visited.

  19. ExoMars Atmospheric Mars Entry and Landing Investigations and Analysis (AMELIA)

    OpenAIRE

    Ferri, F; Forget, F.; Lewis, S R; Karatekin, O.

    2012-01-01

    The entry, descent and landing of ExoMars EDM offers a rare (once-per-mission) opportunity to perform an in situ investigation of the martian environment over a wide altitude range. The ExoMars AMELIA team seeks to exploit the Entry Descent and Landing System (EDLS) engineering measurements for scientific investigations of Mars’ atmosphere and surface. From the measurements recorded during entry and descent, using similar methods and analysis employed on previous entry probe missions (e.g. ES...

  20. Exo-Higgs at 750 GeV and Genesis of Baryons

    CERN Document Server

    Davoudiasl, Hooman; Zhang, Cen

    2016-01-01

    We propose that the diphoton excess at 750~GeV reported by ATLAS and CMS is due to the decay of an ${\\it exo-Higgs}$ scalar $\\eta$ associated with the breaking of a new $SU(2)_e$ symmetry, dubbed ${\\it exo-spin}$. New fermions, ${\\it exo-quarks}$ and ${\\it exo-leptons}$, get TeV-scale masses through Yukawa couplings with $\\eta$ and generate its couplings to gluons and photons at 1-loop. The matter content of our model yields a $B-L$ anomaly under $SU(2)_e$, whose breaking we assume entails a first order phase transition. A non-trivial $B-L$ asymmetry may therefore be generated in the early universe, potentially providing a baryogenesis mechanism through the Standard Model (SM) sphaleron processes. The spontaneous breaking of $SU(2)_e$ can in principle directly lead to electroweak symmetry breaking, thereby accounting for the proximity of the mass scales of the SM Higgs and the exo-Higgs. Our model can be distinguished from those comprising a singlet scalar and vector fermions by the discovery of TeV scale exo...

  1. The ExoMars PanCam Instrument

    Science.gov (United States)

    Griffiths, Andrew; Coates, Andrew; Muller, Jan-Peter; Jaumann, Ralf; Josset, Jean-Luc; Paar, Gerhard; Barnes, David

    2010-05-01

    The ExoMars mission has evolved into a joint European-US mission to deliver a trace gas orbiter and a pair of rovers to Mars in 2016 and 2018 respectively. The European rover will carry the Pasteur exobiology payload including the 1.56 kg Panoramic Camera. PanCam will provide multispectral stereo images with 34 deg horizontal field-of-view (580 microrad/pixel) Wide-Angle Cameras (WAC) and (83 microrad/pixel) colour monoscopic "zoom" images with 5 deg horizontal field-of-view High Resolution Camera (HRC). The stereo Wide Angle Cameras (WAC) are based on Beagle 2 Stereo Camera System heritage [1]. Integrated with the WACs and HRC into the PanCam optical bench (which helps the instrument meet its planetary protection requirements) is the PanCam interface unit (PIU); which provides image storage, a Spacewire interface to the rover and DC-DC power conversion. The Panoramic Camera instrument is designed to fulfil the digital terrain mapping requirements of the mission [2] as well as providing multispectral geological imaging, colour and stereo panoramic images and solar images for water vapour abundance and dust optical depth measurements. The High Resolution Camera (HRC) can be used for high resolution imaging of interesting targets detected in the WAC panoramas and of inaccessible locations on crater or valley walls. Additionally HRC will be used to observe retrieved subsurface samples before ingestion into the rest of the Pasteur payload. In short, PanCam provides the overview and context for the ExoMars experiment locations, required to enable the exobiology aims of the mission. In addition to these baseline capabilities further enhancements are possible to PanCam to enhance it's effectiveness for astrobiology and planetary exploration: 1. Rover Inspection Mirror (RIM) 2. Organics Detection by Fluorescence Excitation (ODFE) LEDs [3-6] 3. UVIS broadband UV Flux and Opacity Determination (UVFOD) photodiode This paper will discuss the scientific objectives and resource

  2. The ExoMars science data archive: status and plans

    Science.gov (United States)

    Heather, David

    2016-07-01

    The ExoMars program, a cooperation between ESA and Roscosmos, comprises two missions: the Trace Gas Orbiter, to be launched in 2016, and a rover and surface platform, due for launch in 2018. This will be the first time ESA has operated a rover, and the archiving and management of the science data to be returned will require a significant effort in development of the new Planetary Science Archive (PSA). The ExoMars mission data will also be formatted according to the new PDS4 Standards, based in XML, and this will be the first data of that format to be archived in the PSA. There are significant differences in the way in which a scientist will want to query, retrieve, and use data from a suite of rover instruments as opposed to remote sensing instrumentation from an orbiter. The PSA data holdings and the accompanying services are currently driven more towards the management of remote sensing data, so some significant changes will be needed. Among them will be a much closer link to the operational information than is currently available for our missions. NASA have a strong user community interaction with their analysts notebook, which provides detailed operational information to explain why, where and when operations took place. A similar approach will be needed for the future PSA, which is currently being designed. In addition to the archiving interface itself, there are differences with the overall archiving process being followed for ExoMars compared to previous ESA planetary missions. The Trace Gas Orbiter data pipelines for the first level of processing from telemetry to raw data, will be hosted directly by ESA's ground segment at ESAC in Madrid, where the archive itself resides. Data will have a continuous flow direct to the PSA, where after the given proprietary period, it will be directly released to the community via the new user interface. For the rover mission, the data pipelines are being developed by European industry, in close collaboration with ESA PSA

  3. Structural Basis of Cytotoxicity Mediated by the Type III Secretion Toxin ExoU from Pseudomonas aeruginosa

    Science.gov (United States)

    Gendrin, Claire; Contreras-Martel, Carlos; Bouillot, Stéphanie; Elsen, Sylvie; Lemaire, David; Skoufias, Dimitrios A.; Huber, Philippe; Attree, Ina; Dessen, Andréa

    2012-01-01

    The type III secretion system (T3SS) is a complex macromolecular machinery employed by a number of Gram-negative pathogens to inject effectors directly into the cytoplasm of eukaryotic cells. ExoU from the opportunistic pathogen Pseudomonas aeruginosa is one of the most aggressive toxins injected by a T3SS, leading to rapid cell necrosis. Here we report the crystal structure of ExoU in complex with its chaperone, SpcU. ExoU folds into membrane-binding, bridging, and phospholipase domains. SpcU maintains the N-terminus of ExoU in an unfolded state, required for secretion. The phospholipase domain carries an embedded catalytic site whose position within ExoU does not permit direct interaction with the bilayer, which suggests that ExoU must undergo a conformational rearrangement in order to access lipids within the target membrane. The bridging domain connects catalytic domain and membrane-binding domains, the latter of which displays specificity to PI(4,5)P2. Both transfection experiments and infection of eukaryotic cells with ExoU-secreting bacteria show that ExoU ubiquitination results in its co-localization with endosomal markers. This could reflect an attempt of the infected cell to target ExoU for degradation in order to protect itself from its aggressive cytotoxic action. PMID:22496657

  4. Crystal structures of two (±-exo-N-isobornylacetamides

    Directory of Open Access Journals (Sweden)

    Dmitrijs Stepanovs

    2015-10-01

    Full Text Available The title compounds consist of a bornane skeleton with attached acetamide, C12H21NO (±-(1 {systematic name: (±-N-[(1RS,2RS,4RS-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl]acetamide}, and chloroacetamide, C12H20ClNO (±-(2 {systematic name: (±-2-chloro-N-[(1RS,2RS,4RS-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl]acetamide}, functionalities to the 2-exo-position. The crystal structure of the first monoclinic polymorph of (±-(1 has been reported previously [Ung et al. (2014. Monatsh. Chem. 145, 983–992]. Compound (±-(1 crystallizes in the space group P21/n with two independent molecules in the asymmetric unit, in contrast to the above-mentioned polymorph which crystallized in the space group C2/c with one molecule in the asymmetric unit. In the title compounds, the bicyclic bornane moieties have normal geometries. In the crystals of both compounds, molecules are linked by N—H...O hydrogen bonds, reinforced by C—H...O contacts, forming trans-amide chains propagating along the a-axis direction. In the case of compound (±-(1, neighbouring chains are linked by further C—H...O contacts, forming double-chain ribbons along [100].

  5. Cortactin and Exo70 mediated invasion of hepatoma carcinoma cells by MMP-9 secretion.

    Science.gov (United States)

    Zhao, Gang; Zhang, Hongyi; Huang, Ziming; Lv, Liping; Yan, Fan

    2016-05-01

    This study was aimed to evaluate the regulation mechanism of cortactin (CTTN) on matrix metalloproteinases 9 (MMP-9) and its relations with Exo70 in invasion of hepatoma carcinoma (HCC) cells. The expression levels of CTTN, Exo70 and MMP-9 were detected in normal hepatocytes and various HCC cells by real-time PCR. Then the migration and invasion ability of these cells was revealed by scratch and invasion assay. The effects of CTTN on MMP-9 and the ability of migration and invasion were evaluated by silence and overexpress CTTN. During this process, the expression of CTTN was detected by Western blot, the activity and concentration of MMP-9 in supernatant of culture medium was detected by zymography and ELISA assay. Besides, Exo70 was also inhibited to reveal its effects on MMP-9 and the migration and invasion ability of LM3. Increased expression of CTTN, MMP-9, Exo70, reduced scratch area and increased puncture cell numbers were found in HCC cells (p < 0.05). The expression of CTTN was significantly correlated with Exo70 and the migration and invasion ability of HCC (p < 0.05). In addition, the activity and concentration of MMP-9 were significantly affected by the expression level of CTTN, while the expression of MMP-9 was not influenced. Besides, Exo70-si also exhibited significantly inhibition effects on the activity and concentration of MMP-9 and puncture cell numbers (p < 0.05). A synergistic reaction may exhibited on CTTN and Exo70, which could mediate the secretion of MMPs thereby regulate tumor invasion. PMID:27025610

  6. The bright end of the exo-Zodi luminosity function: Disk evolution and implications for exo-Earth detectability

    CERN Document Server

    Kennedy, Grant M

    2013-01-01

    We present the first characterisation of the 12um warm dust ("exo-Zodi") luminosity function around Sun-like stars, focussing on the dustiest systems that can be identified by WISE. We detect six new warm dust candidates, five of which have unknown ages. We show that the dustiest old (>Gyr) systems BD+20 307 and HD 15407A are 1 in 10,000 occurrences. Bright warm dust is more common around young (<120Myr) systems, with a ~1% occurrence rate. We show that a two component in situ model where all stars have initially massive warm disks and in which warm debris is also generated at some random time along the stars' main-sequence lifetime, perhaps due to a collision, can explain the observations. However, if all stars only have initially massive warm disks these would not be visible at Gyr ages, and random collisions on the main-sequence are too infrequent to explain the high disk occurrence rate for young stars. That is, neither component can explain the observations on their own. Despite these conclusions, we ...

  7. Binary effectivity rules

    DEFF Research Database (Denmark)

    Keiding, Hans; Peleg, Bezalel

    2006-01-01

    Abstract  A social choice rule (SCR) is a collection of social choice correspondences, one for each agenda. An effectivity rule is a collection of effectivity functions, one for each agenda. We prove that every monotonic and superadditive effectivity rule is the effectivity rule of some SCR. A SCR...... is binary if it is rationalized by an acyclic binary relation. The foregoing result motivates our definition of a binary effectivity rule as the effectivity rule of some binary SCR. A binary SCR is regular if it satisfies unanimity, monotonicity, and independence of infeasible alternatives. A binary...... effectivity rule is regular if it is the effectivity rule of some regular binary SCR. We characterize completely the family of regular binary effectivity rules. Quite surprisingly, intrinsically defined von Neumann-Morgenstern solutions play an important role in this characterization...

  8. Eclipsing binaries in open clusters

    DEFF Research Database (Denmark)

    Southworth, John; Clausen, J.V.

    Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August......Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August...

  9. Precision retrieval of non-isothermal exo-atmospheres

    Science.gov (United States)

    Waldmann, Ingo Peter; Rocchetto, Marco

    2015-12-01

    Spectroscopy of extrasolar planets is as fast moving as it is new. When trying to characterise the atmospheres of these foreign worlds, we are faced with three challenges: 1) The correct treatment of atmospheric opacities at high temperatures, 2) Low signal-to-noise of the observed data, and 3) Large, degenerate parameter spaces. To advance in the interpretation of exoplanetary atmospheres, one must address these challenges in one coherent framework. This is particularly true for emission spectroscopy, where the need for non-isothermal temperature-pressure profiles significantly increases degeneracies in low signal-to-noise data. In the light of these challenges, we developed a novel, bayesian atmospheric retrieval suite, Tau-REx (Waldmann et al. 2015a,b). Tau-REx is a full line-by-line emission/transmission spectroscopy retrieval code based on the most complete hot line-lists from the ExoMol project. For emission spectroscopy, the correct retrieval of the atmosphere’s thermal gradient is extremely challenging with sparse and/or low SNR data. Tau-REx implements a novel two-stage retrieval algorithm which allows the code to iteratively adapt its retrieval complexity to the likelihood surface of the observed data. This way we achieve a very high retrieval accuracy and robustness to low SNR data. Using nested-sampling in conjunction with large scale cluster computing, Tau-REx integrates the full Bayesian Evidence, which allows for precise model selection of the exoplanet’s chemistry and thermal dynamics. Precision and statistical rigour is paramount in the measurement of quantities such as the carbon-oxygen ratio of planets which allow insights into the formation history of these exotic worlds. In this conference I will discuss the intricacies of retrieving the thermal emission of non-isothermal atmospheres and what can be learned from data of current and future facilities.

  10. Anionic cascade reactions. One-pot assembly of (Z-chloro-exo-methylenetetrahydrofurans from β-hydroxyketones

    Directory of Open Access Journals (Sweden)

    István E. Markó

    2013-07-01

    Full Text Available The assembly of (Z-chloro-exo-methylenetetrahydrofurans by an original and connective anionic cascade sequence is reported. Base-catalysed condensation of β-hydroxyketones with 1,1-dichloroethylene generates, in moderate to good yields, the corresponding (Z-chloro-exo-methylenetetrahydrofurans. Acidic treatment of this motif leads to several unexpected dimers, possessing unique structural features.

  11. Charge recombination processes in minerals studied using optically stimulated luminescence and time-resolved exo-electrons

    DEFF Research Database (Denmark)

    Tsukamoto, Sumiko; Murray, Andrew; Ankjærgaard, Christina;

    2010-01-01

    A time-resolved optically stimulated exo-electron (TR-OSE) measurement system has been developed using a Photon Timer attached to a gas-flow semi-proportional pancake electron detector within a Risø TL/OSL reader. The decay rate of the exo-electron emission after the stimulation pulse depends on ...

  12. ENHANCED PRODUCTION OF EXO-POLYGALACTURONASE FROM AGRO-BASED PRODUCTS BY ASPERGILLUS SOJAE

    Directory of Open Access Journals (Sweden)

    Ali Oguz Buyukkileci

    2011-06-01

    Full Text Available Aspergillus sojae has been previously shown to produce exo-polygalacturonase (exo-PG in synthetic media, where the potential of the organism to utilize agricultural substrates was not considered so far. In this study, the utilization of agro-based products was taken into account in the enhanced production of exo-PG using an A. sojae mutant by applying statistical design methods. Complex sources (orange peel, wheat bran, and corn meal, simple sugar sources (glucose, maltrin, and sugar beet syrup, and two phosphate salts were screened using D-optimal design method. Orange peel yielded the highest exo-PG activity with all simple sugars and phosphate sources. According to the results of response surface methodology (RSM, the optimum concentrations of orange peel, sugar beet syrup, and (NH42SO4 were found to be 10, 60, and 8 g L-1, respectively. The exo-PG activity under these conditions was 145.4 U m L-1 in shake flask cultures. In bioreactor studies enzyme production was induced at low pH values; thus highest production was obtained under uncontrolled pH conditions, in which the pH dropped to 2.0 in 72 h. As a result high exo-PG could be produced by an A. sojae mutant using a cost-effective medium containing agro-industrial substrates. Another important advantageous outcome was the low optimal pH, which is especially desired in industrial fermentations prone to contamination problems. In fact this highlights the easy adaptation of this fermentation to industrial scales.

  13. Simultaneous amyloglucosidase and exo-polygalacturonase production by Aspergillus niger using solid-state fermentation

    Directory of Open Access Journals (Sweden)

    Jorge Alberto Vieira Costa

    2007-09-01

    Full Text Available Amyloglucosidase (AMG and exo-polygalacturonase (exo-PG were simultaneously produced by two different strains of Aspergillus niger in solid-state fermentation (SSF using defatted rice-bran as substrate. The effect of Aspergillus niger strain (t0005/007-2 and/or CCT 3312, inoculum type (spore suspension or fermented bran and addition of inducers (pectin and/or starch to the culture media was studied using a 3² x 2¹ factorial experimental design. The production of AMG and exo-PG was significantly affected by fungal strain and inoculum type but inducers had no effect. The maximum yields obtained were 1310 U/g dm for AMG using a spore suspension of A. niger CCT 3312 and 50.2 U/g dm for exo-PG production, using A. niger t0005/007-2 and fermented bran as inoculum. The yields obtained represented acceptable values in comparison with data available in the literature and indicated that defatted rice-bran was a good nutrient source.As enzimas amiloglicosidase (AMG e exo-poligalacturonase (exo-PG foram produzidas simultaneamente por duas cepas de Aspergillus niger, através de fermentação em estado sólido usando farelo de arroz desengordurado como substrato. Foram avaliados os efeitos da cepa de Aspergillus niger, tipo de inóculo e adição de indutores no meio de cultura, utilizando-se um planejamento experimental fracionário 3² x 2¹. O máximo rendimento obtido foi 1310 U/g ms para a produção de AMG e 50,2 U/g ms para a exo-PG. Comparando-se estes resultados com dados da literatura pode-se dizer que os rendimentos obtidos foram aceitáveis e indicam que o farelo de arroz desengordurado é uma boa fonte de nutrientes. A produção de AMG e exo-PG foi significativamente afetada pelas variáveis cepa de A. niger e tipo de inóculo, enquanto a variável indutor não apresentou influência significativa na produção destas enzimas.

  14. Radar Sounding Investigations of the Martian Subsurface by the 2018 ExoMars-C Rover

    OpenAIRE

    Ciarletti, V.; Plettemeier, D.; Cais, Ph.; Clifford, S

    2011-01-01

    The WISDOM (Water Ice Subsurface Deposit Observation on Mars) Ground Penetrating Radar will fly on the ESA-NASA 2018 ExoMars-C mission, which combines the science payload of the original ESA ExoMars Rover with the robotic arm and sample cache of NASA's Max-C Rover into a single rover, whose samples will ult imately be retrieved by a future Mars Sample Return mission. WISDOM was designed to investigate the nearsubsurface down to a depth of ~2-3 m, commensurate with the sampling capabilit ies o...

  15. Variable X-ray emission from the dMe star EXO 040830-7134.7

    International Nuclear Information System (INIS)

    We have identified the serendipitous X-ray source EXO 040830-7134.7 with a mv = 12.5 dMe star. A total of 30 observations of this source were made with the EXOSAT low energy telescope during an interval of 2 years, representing the most complete long term coverage of X-ray emission from a single dMe star. In the usually observed quiescent state, the X-ray luminosity of EXO 040830-7134.7 can be described by a normal distribution with a standard deviation of 0.4 times the average value

  16. Exo-metabolome of some fungal isolates growing on cork-based medium

    DEFF Research Database (Denmark)

    Barreto, M. C.; Frisvad, Jens Christian; Larsen, Thomas Ostenfeld;

    2011-01-01

    are produced by the studied fungal species, both in cork medium or in cork medium added with C. sitophila extracts. However, the addition of C. sitophila extract to the cork medium enhanced the growth of the other studied fungal isolates and altered the respective exo-metabolome profile, leading to......, but also they can be dependent of the remains of former colonizers. In fact, the production of the exo-metabolites by the studied fungal isolates suggests that, under the used experimental conditions, they appear to play an important role in fungal interactions amongst the cork mycoflora....

  17. THOR: an open-source exo-GCM

    Science.gov (United States)

    Grosheintz, Luc; Mendonça, João; Käppeli, Roger; Lukas Grimm, Simon; Mishra, Siddhartha; Heng, Kevin

    2015-12-01

    In this talk, I will present THOR, the first fully conservative, GPU-accelerated exo-GCM (general circulation model) on a nearly uniform, global grid that treats shocks and is non-hydrostatic. THOR will be freely available to the community as a standard tool.Unlike most GCMs THOR solves the full, non-hydrostatic Euler equations instead of the primitive equations. The equations are solved on a global three-dimensional icosahedral grid by a second order Finite Volume Method (FVM). Icosahedral grids are nearly uniform refinements of an icosahedron. We've implemented three different versions of this grid. FVM conserves the prognostic variables (density, momentum and energy) exactly and doesn't require a diffusion term (artificial viscosity) in the Euler equations to stabilize our solver. Historically FVM was designed to treat discontinuities correctly. Hence it excels at resolving shocks, including those present in hot exoplanetary atmospheres.Atmospheres are generally in near hydrostatic equilibrium. We therefore implement a well-balancing technique recently developed at the ETH Zurich. This well-balancing ensures that our FVM maintains hydrostatic equilibrium to machine precision. Better yet, it is able to resolve pressure perturbations from this equilibrium as small as one part in 100'000. It is important to realize that these perturbations are significantly smaller than the truncation error of the same scheme without well-balancing. If during the course of the simulation (due to forcing) the atmosphere becomes non-hydrostatic, our solver continues to function correctly.THOR just passed an important mile stone. We've implemented the explicit part of the solver. The explicit solver is useful to study instabilities or local problems on relatively short time scales. I'll show some nice properties of the explicit THOR. An explicit solver is not appropriate for climate study because the time step is limited by the sound speed. Therefore, we are working on the first fully

  18. PHOEBE: PHysics Of Eclipsing BinariEs

    Science.gov (United States)

    Prsa, Andrej; Matijevic, Gal; Latkovic, Olivera; Vilardell, Francesc; Wils, Patrick

    2011-06-01

    PHOEBE (PHysics Of Eclipsing BinariEs) is a modeling package for eclipsing binary stars, built on top of the widely used WD program (Wilson & Devinney 1971). This introductory paper overviews most important scientific extensions (incorporating observational spectra of eclipsing binaries into the solution-seeking process, extracting individual temperatures from observed color indices, main-sequence constraining and proper treatment of the reddening), numerical innovations (suggested improvements to WD's Differential Corrections method, the new Nelder & Mead's downhill Simplex method) and technical aspects (back-end scripter structure, graphical user interface). While PHOEBE retains 100% WD compatibility, its add-ons are a powerful way to enhance WD by encompassing even more physics and solution reliability.

  19. ExoGeoLab Pilot Project for Landers, Rovers and Instruments

    Science.gov (United States)

    Foing, Bernard

    2010-05-01

    We have developed a pilot facility with a Robotic Test Bench (ExoGeoLab) and a Mobile Lab Habitat (ExoHab). They can be used to validate concepts and external instruments from partner institutes. The ExoGeoLab research incubator project, has started in the frame of a collaboration between ILEWG (International Lunar Exploration working Group http://sci.esa.int/ilewg), ESTEC, NASA and academic partners, supported by a design and control desk in the European Space Incubator (ESI), as well as infrastructure. ExoGeoLab includes a sequence of technology and research pilot project activities: - Data analysis and interpretation of remote sensing and in-situ data, and merging of multi-scale data sets - Procurement and integration of geophysical, geo-chemical and astrobiological breadboard instruments on a surface station and rovers - Integration of cameras, environment and solar sensors, Visible and near IR spectrometer, Raman spectrometer, sample handling, cooperative rovers - Delivery of a generic small planetary lander demonstrator (ExoGeoLab lander, Sept 2009) as a platform for multi-instruments tests - Research operations and exploitation of ExoGeoLab test bench for various conceptual configurations, and support for definition and design of science surface packages (Moon, Mars, NEOs, outer moons) - Field tests of lander, rovers and instruments in analogue sites (Utah MDRS 2009 & 2010, Eifel volcanic park in Sept 2009, and future campaigns). Co-authors, ILEWG ExoGeoLab & ExoHab Team: B.H. Foing(1,11)*#, C. Stoker(2,11)*, P. Ehrenfreund(10,11), L. Boche-Sauvan(1,11)*, L. Wendt(8)*, C. Gross(8, 11)*, C. Thiel(9)*, S. Peters(1,6)*, A. Borst(1,6)*, J. Zavaleta(2)*, P. Sarrazin(2)*, D. Blake(2), J. Page(1,4,11), V. Pletser(5,11)*, E. Monaghan(1)*, P. Mahapatra(1)#, A. Noroozi(3), P. Giannopoulos(1,11) , A. Calzada(1,6,11), R. Walker(7), T. Zegers(1, 15) #, G. Groemer(12)# , W. Stumptner(12)#, B. Foing(2,5), J. K. Blom(3)#, A. Perrin(14)#, M. Mikolajczak(14)#, S. Chevrier(14

  20. ExoGeoLab Test Bench for Landers, Rovers and Instruments

    Science.gov (United States)

    Foing, B. H.

    2009-04-01

    In the frame of ESTEC technology and research pilot project, we have started a small pilot facility with a ExoGeoLab and a mini-Habitat, supported by two design and control offices in the European Space Incubator (ESI), as well as infrastructure support and manpower. We have in addition to contribution on external instruments and manpower from partner institutes. From this test bench and kit of ExoGeoLab instruments, we plan to operate comprehensive instruments packages that could help in the technical research and science preparation of lander/rover missions studied in the frame of Cosmic Vision or the Exploration programme. The ExoGeoLab research incubator project includes a sequence of activities: - Data analysis and interpretation of remote sensing data (MEX, SMART-1, VEX, Cassini-Huygens) and in-situ (Huygens, MER) , and merging of multi-scale data sets - Procurement and integration of geophysical, geochemical and astrobiological breadboard instruments in an surface station and rover (ExoGeoLab) - Research operations and exploitation of ExoGeoLab test bench for various conceptual configurations (Moon, Mars, NEO, Titan) - Contribution to the exploitation of surface lander results (MER, Phenix, MSL, preparation Exomars) - Scientific simulation of planetary surfaces using laboratory and modelling tools - Support research for definition and design of science surface packages on the Moon, Mars, NEO, Titan - Research support to community preparation of payload for surface lander opportunities Specific goals and methods of ESTEC ExoGeoLab: we have started to integrate instruments in an ExoGeoLab crossing various techniques. The methodic steps for this hands-on research are: 1) We have procured and adapted instruments to equip a mid-size ExoGeoRover (made available in collaboration with ESTEC robotics section), and a small surface station. 2) This terrestrial payload (instruments, sensors, data handling) will be deployed, operated and used as collaborative research

  1. Synthesis of cycloheptanoid natural products via tandem 5-exo cyclization/Claisen rearrangement process

    OpenAIRE

    Ovaska, Timo V.

    2010-01-01

    This article describes the development of microwave-assisted oxyanionic 5-exo-dig cyclization-Claisen rearrangement sequence as a convenient “one-pot” route to a variety of seven-membered carbocyclic ring systems. This process was used as the key transformation for the construction of several natural products, including frondosins A, B, and C.

  2. Subsite binding energies of an exo-polygalacturonase using isothermal titration calorimetry

    Science.gov (United States)

    Thermodynamic parameters for binding of a series of galacturonic acid oligomers to an exo-polygalacturonase, RPG16 from Rhizopus oryzae, were determined by isothermal titration calorimetry. Binding of oligomers varying in chain length from two to five galacturonic acid residues is an exothermic proc...

  3. Radiation environment investigations during ExoMars missions to Mars – objectives, experiments and instrumentation

    International Nuclear Information System (INIS)

    Deep space manned missions are already a near future of astronautics. Radiation risk on such a long-duration journey appears to be one of the basic factors in planning and designing the mission. The paper relates to the scientific objectives and experiments for investigation of the radiation environment to be carried out during the ExoMars 2016 and 2018 joint missions of the European Space Agency (ESA) and the Federal Space Agency of Russia (Roscosmos) to Mars. The following topics are described: 1) The charged particle telescope and the experiment Liulin-MO for measuring the radiation environment on board the ExoMars 2016 Trace Gas Orbiter satellite as a part of the Fine Resolution Epithermal Neutron Detector (FREND) and 2) Liulin-ML experiment and instrument for investigating the radiation environment on Mars as a part of the active detector of neutrons and gamma rays (ADRON) on the Russian surface platform for ExoMars 2018 mission. Liulin detectors will be used in combination with the neutron detectors to study the radiation conditions both from charged particles and neutrons during the cruise phase, in Mars orbit and on the surface of Mars. Key words: space radiation, radiation risk, space radiation measurements, interplanetary missions, ExoMars

  4. Hydrogen delivery onto white dwarfs from remnant exo-Oort cloud comets

    Science.gov (United States)

    Veras, Dimitri; Shannon, Andrew; Gänsicke, Boris T.

    2014-12-01

    The origin of trace hydrogen in white dwarfs (WDs) with He-dominated atmospheres is a long-standing problem, one that cannot satisfactorily be explained by the historically favoured hypothesis of accretion from the interstellar medium. Here we explore the possibility that the gradual accretion of exo-Oort cloud comets, which are a rich source of H, contributes to the apparent increase of trace H with WD cooling age. We determine how often remnant exo-Oort clouds, freshly excited from post-main-sequence stellar mass loss, dynamically inject comets inside the WD's Roche radius. We improve upon previous studies by considering a representative range of single WD masses (0.52-1.00 M⊙) and incorporating different cloud architectures, giant branch stellar mass loss, stellar flybys, Galactic tides and a realistic escape ellipsoid in self-consistent numerical simulations that integrate beyond 8 Gyr ages of WD cooling. We find that ˜10-5 of the material in an exo-Oort cloud is typically amassed on to the WD, and that the H deposits accumulate even as the cloud dissipates. This accumulation may account for the relatively large amount of trace H, 1022-1025 g, that is determined frequently among WDs with cooling ages ≥1 Gyr. Our results also reaffirm the notion that exo-Oort cloud comets are not the primary agents of the metal budgets observed in polluted WD atmospheres.

  5. Micro-Ares, An electric field sensor for ExoMars 2016

    OpenAIRE

    Déprez, Grégoire; Montmessin, Franck; Witasse, Olivier; Lapauw, Laurent; Vivat, Francis; Abbaki, Sadok; Granier, Philippe; Moirin, David; Trautner, Roland; Hassen-Khodja, Rafik; D'Almeida, Eric; Chardenal, Laurent; Berthelier, Jean-Jacques; Esposito, F.; Debei, S.

    2015-01-01

    For the past few years, LATMOS has been involved in the development of Micro-ARES, an electric field sensor part of the science payload (DREAMS) of the ExoMars 2016 Schiaparelli entry, descent and landing demonstrator module (EDM). It is dedicated to the very first measurement and characterization of the Martian atmospheric electricity.

  6. Ballistics and navigation of the flight and descent of the ExoMars-2018 landing module

    Science.gov (United States)

    Evgrafov, A. E.; Morskoy, I. M.; Simonov, A. V.; Dobrovolskiy, V. S.; Tuchin, A. G.; Grushevskii, A. V.; Zaslavskiy, G. S.; Stepaniants, V. A.

    2015-12-01

    The main cruise phases of the spacecraft of the ExoMars-2018 mission are considered. Basic ballistic characteristics of the spacecraft operation during the cruise phase to Mars and during the phase at the planet's surface according to the current development status of the European-Russian project are given.

  7. Modelling High Resolution Absorption Spectra with ExoMolLine Lists: NH3and CH4

    DEFF Research Database (Denmark)

    Barton, E. J.; Yurchenko, S. N.; Tennyson, J.;

    [1]. For this reason, a smart collaboration has been established between Optical Diagnostics Group at DTU and ExoMol, to combine high resolution spectra measured at elevated temperatures and empirically tuned ab initio methods to produce suitable molecular line lists for modelling molecules in...

  8. Exo-polygalacturonase production by Penicillium roqueforti on pumpkin oil cake in solid state fermentation

    Directory of Open Access Journals (Sweden)

    Peričin Draginja M.

    2007-01-01

    Full Text Available The feasibility of using pumpkin oil cake (PuOC, individual and in combination with wheat bran (WB, as substrate for the production of Exo-polygalacturonase (Exo-p by starter culture Penicillium roqueforti in solid state fermentation (SSF has been evaluated. The kinetics of enzyme production was investigated using PuOC alone in the range from 13 to 168 h, with moisture contents varying from 44% the ability to grow and produce Exo-p activity on this substrate, reaching a maximum value of 1451.75 U/g.d.w PuOC by the 5th day of fermentation. Fermentation experiments indicated that the water activity (aw influenced the enzyme production. A medium with aw 0.932 and the fermentation time of 5 days were selected, as these conditions resulted in the highest pectolytic activity and were used for further investigation. A next step in this research was to examine the effect of the substrate combination, PuOC with wheat bran (WB, in different ratios. The addition of WB as carbon sources was found to have a significant influence on the enzymes yields. Exo-p activities were the highest with initial water activity of a w 0.932 and PuOC supplementation with WB (1:0.67.

  9. Loss of mitochondrial exo/endonuclease EXOG affects mitochondrial respiration and induces ROS mediated cardiomyocyte hypertrophy

    NARCIS (Netherlands)

    Tigchelaar, Wardit; Yu, Hongjuan; De Jong, Anne Margreet; van Gilst, Wiek H; van der Harst, Pim; Westenbrink, B Daan; de Boer, Rudolf A; Sillje, Herman H W

    2015-01-01

    Recently, a genetic variant in the mitochondrial exo/endo nuclease EXOG, which has been implicated in mitochondrial DNA repair, was associated with cardiac function. The function of EXOG in cardiomyocytes is still elusive. Here we investigated the role of EXOG in mitochondrial function and hypertrop

  10. Catalytic asymmetric exo-selective [6+3] cycloaddition of iminoesters with fulvenes.

    Science.gov (United States)

    Potowski, Marco; Antonchick, Andrey P; Waldmann, Herbert

    2013-09-14

    A novel exo-selective [6+3] cycloaddition approach for the highly enantioselective synthesis of polysubstituted piperidines was developed. The developed methodology was applied in a one-pot [6+3]-[4+2] dicycloaddition, allowing the construction of structurally and stereochemically rich polycyclic compounds from simple building blocks. PMID:23884088

  11. Micro-Ares, An electric field sensor for ExoMars 2016

    Science.gov (United States)

    Déprez, G.; Montmessin, F.; Witasse, O.; Lapauw, L.; Vivat, F.; Abbaki, S.; Granier, P.; Moirin, D.; Trautner, R.; Hassen-Khodja, R.; d'Almeida, E.; Chardenal, L.; Berthelier, J.-J.; Espositi, F.; Debei, S.; Rafkin, S.; Barth, E.

    2015-10-01

    For the past few years, LATMOS has been involved in the development of Micro-ARES, an electric field sensor part of the science payload (DREAMS) of the ExoMars 2016 Schiaparelli entry, descent and landing demonstratormodule (EDM). It is dedicated to the very first measurement and characterization of the Martian atmospheric electricity.

  12. Encounters of binaries

    International Nuclear Information System (INIS)

    Numerical integrations of encounters of pairs of binaries have been used to study the class of interactions, called fly-bys, in which the two-binary configuration survives. It is shown that these typically weak interactions can be treated by means of a first-order perturbation theory. A simple simulation model for obtaining the energy transfer rate between various degrees of freedom has been constructed. The model was employed to estimate the additional energy transfer arising from impact parameters larger than those used in the numerical experiments. In the hard binary limit the total energy transfer caused by binary-binary encounters is dominated by the collisional interactions in which the two-binary configuration is destroyed. (author)

  13. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  14. The Hypanis fluvial deltaic system in Xanthe Terra: a candidate ExoMars 2018 Rover landing site

    OpenAIRE

    Sefton-Nash, E.; Fawdon, P.; Gupta, S.; Balme, M.; Davis, J; Grindrod, P.; Sidiropoulos, P.; Yershov, V.; Muller, J.-P.

    2015-01-01

    The search for life on Mars is a cornerstone of international solar system exploration. In 2018, the European Space agency will launch the ExoMars Rover to further this goal. The key science objectives of the ExoMars Rover are to: 1) search for signs of past and present life on Mars; 2) investigate the water/geochemical environment as a function of depth in the shallow subsurface; and 3) to characterize the surface environment. ExoMars will drill into the sub-surface to look for indicators of...

  15. Measurement of the Drift Velocity and Transverse Diffusion of Electrons in Liquid Xenon with the EXO-200 Detector

    CERN Document Server

    :,; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Cen, W R; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Daughhetee, J; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dilling, J; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feyzbakhsh, S; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Hughes, M; Jewell, M J; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krucken, R; Kuchenkov, A; Kumar, K S; Lan, Y; Leonard, D S; Licciardi, C; Lin, Y H; MacLellan, R; Marino, M G; Mong, B; Moore, D; Njoya, O; Nelson, R; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Retiere, F; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya; Zettlemoyer, J

    2016-01-01

    The EXO-200 Collaboration is searching for neutrinoless double beta decay using a liquid xenon (LXe) time projection chamber. This measurement relies on modeling the transport of charge deposits produced by interactions in the LXe to allow discrimination between signal and background events. Here we present measurements of the transverse diffusion constant and drift velocity of electrons at drift fields between 20~V/cm and 615~V/cm using EXO-200 data. At the operating field of 380~V/cm EXO-200 measures a drift velocity of 1.705$_{-0.010}^{+0.014}$~mm/$\\mu$s and a transverse diffusion coefficient of 55$\\pm$4~cm$^2$/s.

  16. Simud Vallis Floor: A Joint Landing Site for both the ExoMars 2018 and the Mars 2020 Rovers

    Science.gov (United States)

    Pajola, M.; Rossato, S.; Baratti, E.; Mangili, C.; Mancarella, F.; McBride, K. S.; Coradini, M.

    2014-07-01

    The geomorphological, mineralogical and the surface engineering properties of the Simud Vallis floor are presented. This region is scientifically compelling and a safe landing area for both the ExoMars 2018 and the Mars 2020 rovers.

  17. "Where On Mars?": A Web Map Visualisation of the ExoMars 2018 Rover Candidate Landing Sites

    Science.gov (United States)

    Manaud, N.; Boix, O.; Vago, J.; Hill, A.; Iriberri, C.; Carrión, D.

    2015-10-01

    The ExoMars 2018 mission will deliver a European rover and a Russian surface platform to the surface of Mars. Armed with a drill that can bore 2 metres into rock, the ExoMars rover will travel across the Martian surface to search for signs of life, past or present. But where on Mars to land? - The search for a suitable ExoMars rover landing site began in December 2013, when the planetary science community was asked to propose candidates. Eight proposals were considered during a workshop held by the ExoMars Landing Site Selection Working Group (LSSWG). By the end of the workshop, there were four clear front-runners. Following additional review, the four sites have now been formally recommended for further detailed analysis [1]: Mawrth Vallis, Oxia Planum, Hypanis Vallis and Aram Dorsum. Scientists will continue working on the characterisation of these four sites until they provide their final recommendation in October 2017.

  18. Exo-pectinase production by Bacillus pumilus using different agricultural wastes and optimizing of medium components using response surface methodology.

    Science.gov (United States)

    Tepe, Ozlem; Dursun, Arzu Y

    2014-01-01

    In this research, the production of exo-pectinase by Bacillus pumilus using different agricultural wastes was studied. Agricultural wastes containing pectin such as wheat bran, sugar beet pulp, sunflower plate, orange peel, banana peel, apple pomace and grape pomace were tested as substrates, and activity of exo-pectinase was determined only in the mediums containing sugar beet pulp and wheat bran. Then, effects of parameters such as concentrations of solid substrate (wheat bran and sugar beet pulp) (A), ammonium sulphate (B) and yeast extract (C) on the production of exo-pectinase were investigated by response surface methodology. First, wheat bran was used as solid substrate, and it was determined that exo-pectinase activity increased when relatively low concentrations of ammonium sulphate (0.12-0.21% w/v) and yeast extract (0.12-0.3% w/v) and relatively high wheat bran (~5-6% w/v) were used. Then, exo-pectinase production was optimized by response surface methodology using sugar beet pulp as a solid substrate. In comparison to P values of the coefficients, values of not greater than 0.05 of A and B (2) showed that the effect of these process variables in exo-pectinase production was important and that changes done in these variables will alter the enzyme activity. PMID:24819433

  19. The DREAMS experiment on-board the Schiaparelli lander of ExoMars mission

    Science.gov (United States)

    Esposito, F.

    2015-10-01

    The DREAMS package is a suite of sensors for the characterization of the Martian basic state meteorology and of the atmospheric electric properties at the landing site of the Entry, descent and landing Demonstration Module (EDM) of the ExoMars mission. The EDM will land on Meridiani Planum in October 2016, during the statistical dust storm season. This will allow DREAMS to investigate the status of the atmosphere of Mars during this particular season and also to understand the role of dust as a potential source of electrical phenomena on Mars. DREAMS will be the first instrument to perform a measurement of electric field on Mars. DREAMS FM has been completely developed and tested and it has been delivered to ESA for integration on the Schiaparelli lander of the ExoMars 2016 mission. Launch is foreseen for January 2016.

  20. The ExoMol database: molecular line lists for exoplanet and other hot atmospheres

    CERN Document Server

    Tennyson, Jonathan; Al-Refaie, Ahmed F; Barton, Emma J; Chubb, Katy L; Coles, Phillip A; Diamantopoulou, S; Gorman, Maire N; Hill, Christian; Lam, Aden Z; Lodi, Lorenzo; McKemmish, Laura K; Na, Yueqi; Owens, Alec; Polyansky, Oleg L; Sousa-Silva, Clara; Underwood, Daniel S; Yachmenev, Andrey; Zak, Emil

    2016-01-01

    The ExoMol database (www.exomol.com) provides extensive line lists of molecular transitions which are valid over extended temperatures ranges. The status of the current release of the database is reviewed and a new data structure is specified. This structure augments the provision of energy levels (and hence transition frequencies) and Einstein $A$ coefficients with other key properties, including lifetimes of individual states, temperature-dependent cooling functions, Land\\'e $g$-factors, partition functions, cross sections, $k$-coefficients and transition dipoles with phase relations. Particular attention is paid to the treatment of pressure broadening parameters. The new data structure includes a definition file which provides the necessary information for utilities accessing ExoMol through its application programming interface (API). Prospects for the inclusion of new species into the database are discussed.

  1. Isolation and Characterization of Lactic Acid Bacteria (LAB) Produced Exo cellular Polysaccharide

    International Nuclear Information System (INIS)

    Isolation and characterization of exo cellular polysaccharide was studied in order to evaluate some parameters in the synthesis of exo polysaccharide (EPS) and improve their production through submerged fermentation processes. Isolation strains Lactobacillus delbrueckii ssp bulgaricus (IS1), Lactococcus lactis ssp cremoris (IS2) and Lactobacillus delbrueckii ssp bulgaricus (IS3) were studied in shake flasks using yeast extract, surfactants and different exposure doses of gamma irradiation.The optimum concentration of (EPS) formation (0.762 g/l) by Lactococcus lactis ssp cremoris (IS2), 3.0 (g/l) yeast extract, 1.72 (g/l) at 0.5 (%) surfactant Triton X-100. Also, EPS (1.842 g/l) was produced when Lactococcus lactis ssp cremoris (IS2) exposed to 0.2 kGy dose level.

  2. Phylogenetic Co-Occurrence of ExoR, ExoS, and ChvI, Components of the RSI Bacterial Invasion Switch, Suggests a Key Adaptive Mechanism Regulating the Transition between Free-Living and Host-Invading Phases in Rhizobiales

    OpenAIRE

    Heavner, Mary Ellen; Qiu, Wei-Gang; Cheng, Hai-Ping

    2015-01-01

    Both bacterial symbionts and pathogens rely on their host-sensing mechanisms to activate the biosynthetic pathways necessary for their invasion into host cells. The Gram-negative bacterium Sinorhizobium meliloti relies on its RSI (ExoR-ExoS-ChvI) Invasion Switch to turn on the production of succinoglycan, an exopolysaccharide required for its host invasion. Recent whole-genome sequencing efforts have uncovered putative components of RSI-like invasion switches in many other symbiotic and patho...

  3. Search for Neutrinoless Double-Beta Decay in $^{136}$Xe with EXO-200

    CERN Document Server

    Auger, M; Barbeau, P S; Beauchamp, E; Belov, V; Benitez-Medina, C; Breidenbach, M; Brunner, T; Burenkov, A; Cleveland, B; Cook, S; Daniels, T; Danilov, M; Davis, C G; Delaquis, S; deVoe, R; Dobi, A; Dolinski, M J; Dolgolenko, A; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Fierlinger, P; Franco, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Hall, C; Hall, K; Hargrove, C; Herrin, S; Hughes, M; Johnson, A; Johnson, T N; Karelin, A; Kaufman, L J; Kuchenkov, A; Kumar, K S; Leonard, D S; Leonard, F; Mackay, D; MacLellan, R; Marino, M; Mong, B; Diez, M Montero; Muller, A R; Neilson, R; Nelson, R; Odian, A; Ostrovskiy, I; O'Sullivan, K; Ouellet, C; Piepke, A; Pocar, A; Prescott, C Y; Pushkin, K; Rowson, P C; Russell, J J; Sabourov, A; Sinclair, D; Slutsky, S; Stekhanov, V; Tolba, T; Tosi, D; Twelker, K; Vogel, P; Vuilleumier, J -L; Waite, A; Walton, T; Weber, M; Wichoski, U; Wodin, J; Wright, J D; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2012-01-01

    We report on a search for neutrinoless double-beta decay of $^{136}$Xe with EXO-200. No signal is observed for an exposure of 32.5 kg-yr, with a background of ~1.5 x 10^{-3} /(kg yr keV) in the $\\pm 1\\sigma$ region of interest. This sets a lower limit on the half-life of the neutrinoless double-beta decay $T_{1/2}^{0\

  4. Medicine and ionizing rays: a help sheet in analysing risks in exo-buccal dental radiology

    International Nuclear Information System (INIS)

    This document proposes a synthesis of useful knowledge for radioprotection in the case of exo-buccal dental radiology. In the first part, several aspects are considered: the concerned personnel, the course of treatment procedures, the hazards, the identification of the risk associated with ionizing radiation, the risk assessment and the determination of exposure levels, the strategy to control the risks (reduction of risks, technical measures concerning the installation or the personnel, teaching and information, prevention and medical monitoring), and risk control assessment

  5. New Concept for Internal Heat Production in Hot Jupiter Exo-Planets

    OpenAIRE

    Herndon, J. Marvin

    2006-01-01

    Discovery of hot Jupiter exo-planets, those with anomalously inflated size and low density relative to Jupiter, has evoked much discussion as to possible sources of internal heat production. But to date, no explanations have come forth that are generally applicable. The explanations advanced typically involve presumed tidal dissipation and/or converted incident stellar radiation. The present, brief communication suggests a novel interfacial nuclear fission-fusion source of internal heat produ...

  6. The ExoMol project: Software for computing large molecular line lists

    OpenAIRE

    Tennyson, Jonathan; Yurchenko, S. N.

    2016-01-01

    The use of variational nuclear motion programs to compute line lists of transition frequencies and intensities is now a standard procedure. The ExoMol project has used this technique to generate line lists for studies of hot bodies such as the atmospheres of exoplanets and cool stars. The resulting line list can be huge: many contain 10 billion or more transitions. This software update considers changes made to our programs during the course of the project to allow for such calculations. This...

  7. Rosiglitazone Balances Insulin-Induced Exo- And Endocytosis In Single 3t3-L1 Adipocytes

    OpenAIRE

    Velebit, Jelena; Chowdhury, Helena H.; Kreft, Marko; Zorec, Robert

    2011-01-01

    Abstract Rosiglitazone (Rosi) improves insulin sensitivity and increases the translocation of glucose transporter 4 (GLUT4) to the plasma membrane (PM). This involves the fusion of membrane-bound compartments with the plasma membrane, thus increasing the plasma membrane area. However, recent work has shown that in Rosi-pretreated 3T3-L1 adipocytes membrane area did not increase following insulin application, suggesting that the rates of exo- and endocytosis are balanced. Here we ex...

  8. Investigating the Martian atmosphere using the ExoMars 2016 lander

    OpenAIRE

    Chapman, R M; Lewis, S R; Balme, M. R.; Steele, L. J.

    2015-01-01

    Accurate modelling of the Martian atmosphere is essential both for planning and completing future missions to the Martian surface, and for accurate analysis and interpretation of the data that they return. Large dust storms and local wind patterns can affect spacecraft landing profiles, and the level of dust present in the atmosphere may impact lander performance. The ExoMars 2016 Mission will carry an Entry, Descent and Landing Demonstrator Module (EDM), primarily designed to test the abilit...

  9. Planning and Implementation of Pressure and Humidity Measurements on ExoMars 2016 Schiaparelli Lander

    Science.gov (United States)

    Nikkanen, T.; Schmidt, W.; Genzer, M.; Komu, M.; Kemppinen, O.; Haukka, H.; Harri, A.-M.

    2014-04-01

    The ExoMars 2016 Schiaparelli lander offers a platform for meteorological and electric field observations ranging from timescales of seconds to Martian days, or sols. In the Finnish Meteorological Institute (FMI), this opportunity has been used to develop a new type of instrument controller unit for the already flight-proven FMI pressure and humidity instruments. The new controller allows for more flexible and autonomous data acquisition processes and planning than the previous FMI designs.

  10. Templated assembly of medium cyclic ethers via exo-trig nucleophilic cyclization of cyclopropenes.

    Science.gov (United States)

    Alnasleh, Bassam K; Rubina, Marina; Rubin, Michael

    2016-06-14

    A novel method for the assembly of medium heterocycles via an intramolecular nucleophilic addition to cyclopropenes generated in situ from the corresponding bromocyclopropanes is described. The exo-trig nucleophilic cyclizations were shown to proceed very efficiently and in a highly diastereoselective fashion affording cis-fused bicyclic products possessing 7 to 10-membered medium rings; starting from a diastereomeric mixtures of bromocyclopropanes. PMID:27210442

  11. Exo and endo-glucanolytic activity of cellulases purified from Trichoderma reesei

    OpenAIRE

    Gama, F. M.; Vilanova, Manuel; Mota, M

    1998-01-01

    Four cellulases, produced by Trichoderma reesei, have been purified by preparative isoelectric focusing (Rotofor), size exclusion (Sephacryl 100 HR), anionic (Mono Q) and cationic (Mono S) chromatography and chromatofocusing (Mono P). Enzymatic activity with a large number of substrates allowed the proteins to be classified as: cellobiohydrolase I, cellobiohydrolase II, endoglucanase I and endoglucanase II. The exo- or endo- glucanase character of these enzymes was analysed by using a techniq...

  12. Exo+ proofreading polymerases mediate genetic analysis and its application in biomedical studies

    Institute of Scientific and Technical Information of China (English)

    Duan-fang LIAO; Lin-ling CHEN; Cui-ying PENG; Jia ZHANG; Kai LI

    2005-01-01

    Polymerases with a proofreading function in their internal 3' to 5' exonuclease possess high fidelity for DNA replication both in vivo and in vitro. The obstacle facing Exo+ polymerases for single nucleotide polymorphism (SNP) detection could be bypassed by using primer-3'-termini modification. This hypothesis has been well tested using three types of modified allele specific primers with: 3' labeling, 3'to 5'exonuclease resistance, and 3'dehydroxylation. Accordingly, three new SNP assaying methods have been developed to carry out genome-wide genotyping,taking advantage of the enzymatic properties of Exo+ polymerases. These new mutation detection assays are widely adaptable to a variety of platforms, including multi-well plate and microarray technologies. Application of Exo+ polymerases to genetic analysis, including genotyping that is mostly relevant to pharmacogenetics, high-fidelity gene expression profiling, rare mutation detection and mutation load assay, will help to accelerate the pace of personalized medicine. In this review paper, we will first introduce three new assays that we have recently developed, and then describe a number of their applications in pharmacogenetics and in other biomedical studies.

  13. Hydrogen delivery onto white dwarfs from remnant exo-Oort cloud comets

    CERN Document Server

    Veras, Dimitri; Gaensicke, Boris T

    2014-01-01

    The origin of trace hydrogen in white dwarfs (WDs) with He-dominated atmospheres is a long-standing problem, one that cannot satisfactorily be explained by the historically-favoured hypothesis of accretion from the interstellar medium. Here we explore the possibility that the gradual accretion of exo-Oort cloud comets, which are a rich source of H, contributes to the apparent increase of trace H with WD cooling age. We determine how often remnant exo-Oort clouds, freshly excited from post-main-sequence stellar mass loss, dynamically inject comets inside the WD's Roche radius. We improve upon previous studies by considering a representative range of single WD masses (0.52-1.00 Solar masses) and incorporating different cloud architectures, giant branch stellar mass loss, stellar flybys, Galactic tides and a realistic escape ellipsoid in self-consistent numerical simulations that integrate beyond 8 Gyr ages of WD cooling. We find that about 10^{-5} of the material in an exo-Oort cloud is typically amassed onto t...

  14. Evaluation of exo-endo ratios in the halolactonization of omega-unsaturated acids.

    Science.gov (United States)

    Roux, M C; Paugam, R; Rousseau, G

    2001-06-15

    The reaction of 2-(omega-alkenyl)benzoic acids with bis(collidine)iodine and bis(collidine)bromine hexafluorophosphate was examined. Except with 2-but-3-enylbenzoic acid, for which only the exo lactone was obtained, for the other acids a mixture of exo-endo lactones was always obtained. The proportion of endo lactone was important for the acid chain length of 11 carbons (formation of a 12-membered ring endo lactone) and for the acid chain lengths higher than 14 carbons. The formation of the endo lactones was explained, on the base of molecular calculations, by competition between electronic and steric effects. These latter were developed by transannular interactions (for the acid chain lengths 8-11) and/or the conformations adopted by the chains (for the acid chain lengths > or = 14,) which disfavored the formation of the exo lactones. The larger proportion of endo lactones observed with the bromo reagent compared to the iodo reagent seemed due to electronic factors. PMID:11397168

  15. Rif1 and Exo1 regulate the genomic instability following telomere losses.

    Science.gov (United States)

    Xue, Yuan; Marvin, Marcus E; Ivanova, Iglika G; Lydall, David; Louis, Edward J; Maringele, Laura

    2016-06-01

    Telomere attrition is linked to cancer, diabetes, cardiovascular disease and aging. This is because telomere losses trigger further genomic modifications, culminating with loss of cell function and malignant transformation. However, factors regulating the transition from cells with short telomeres, to cells with profoundly altered genomes, are little understood. Here, we use budding yeast engineered to lack telomerase and other forms of telomere maintenance, to screen for such factors. We show that initially, different DNA damage checkpoint proteins act together with Exo1 and Mre11 nucleases, to inhibit proliferation of cells undergoing telomere attrition. However, this situation changes when survivors lacking telomeres emerge. Intriguingly, checkpoint pathways become tolerant to loss of telomeres in survivors, yet still alert to new DNA damage. We show that Rif1 is responsible for the checkpoint tolerance and proliferation of these survivors, and that is also important for proliferation of cells with a broken chromosome. In contrast, Exo1 drives extensive genomic modifications in survivors. Thus, the conserved proteins Rif1 and Exo1 are critical for survival and evolution of cells with lost telomeres. PMID:27004475

  16. ExoLocator--an online view into genetic makeup of vertebrate proteins.

    Science.gov (United States)

    Khoo, Aik Aun; Ogrizek-Tomas, Mario; Bulovic, Ana; Korpar, Matija; Gürler, Ece; Slijepcevic, Ivan; Šikic, Mile; Mihalek, Ivana

    2014-01-01

    ExoLocator (http://exolocator.eopsf.org) collects in a single place information needed for comparative analysis of protein-coding exons from vertebrate species. The main source of data--the genomic sequences, and the existing exon and homology annotation--is the ENSEMBL database of completed vertebrate genomes. To these, ExoLocator adds the search for ostensibly missing exons in orthologous protein pairs across species, using an extensive computational pipeline to narrow down the search region for the candidate exons and find a suitable template in the other species, as well as state-of-the-art implementations of pairwise alignment algorithms. The resulting complements of exons are organized in a way currently unique to ExoLocator: multiple sequence alignments, both on the nucleotide and on the peptide levels, clearly indicating the exon boundaries. The alignments can be inspected in the web-embedded viewer, downloaded or used on the spot to produce an estimate of conservation within orthologous sets, or functional divergence across paralogues. PMID:24271393

  17. ExoCarta: A Web-Based Compendium of Exosomal Cargo.

    Science.gov (United States)

    Keerthikumar, Shivakumar; Chisanga, David; Ariyaratne, Dinuka; Al Saffar, Haidar; Anand, Sushma; Zhao, Kening; Samuel, Monisha; Pathan, Mohashin; Jois, Markandeya; Chilamkurti, Naveen; Gangoda, Lahiru; Mathivanan, Suresh

    2016-02-22

    Exosomes are membranous vesicles that are released by a variety of cells into the extracellular microenvironment and are implicated in intercellular communication. As exosomes contain RNA, proteins and lipids, there is a significant interest in characterizing the molecular cargo of exosomes. Here, we describe ExoCarta (http://www.exocarta.org), a manually curated Web-based compendium of exosomal proteins, RNAs and lipids. Since its inception, the database has been highly accessed (>54,000 visitors from 135 countries). The current version of ExoCarta hosts 41,860 proteins, >7540 RNA and 1116 lipid molecules from more than 286 exosomal studies annotated with International Society for Extracellular Vesicles minimal experimental requirements for definition of extracellular vesicles. Besides, ExoCarta features dynamic protein-protein interaction networks and biological pathways of exosomal proteins. Users can download most often identified exosomal proteins based on the number of studies. The downloaded files can further be imported directly into FunRich (http://www.funrich.org) tool for additional functional enrichment and interaction network analysis. PMID:26434508

  18. ESA ExoMars program: The next step in exploring Mars

    Science.gov (United States)

    Vago, J.; Witasse, O.; Svedhem, H.; Baglioni, P.; Haldemann, A.; Gianfiglio, G.; Blancquaert, T.; McCoy, D.; de Groot, R.

    2015-12-01

    The ExoMars program is an ESA-Roscosmos cooperation with some NASA contributions. ExoMars consists of two missions, one in 2016 and one in 2018. The 2016 mission includes an orbiting satellite dedicated to the study of atmospheric trace gases to acquire information on possible on-going geological or biological processes, and a European entry, descent, and landing demonstrator module (EDM) to achieve a successful soft landing on Mars. The orbiter can also provide data communication services for all surface missions landing on Mars until the end of 2022. The 2018 mission is planned to deliver a 300-kg-class rover and an instrumented landing platform to the Martian surface using a landing system developed by Roscosmos. The 2018 mission is to pursue one of the most outstanding questions of our time by attempting to establish whether life ever existed, or is still present, on Mars today. The article gives an overview of the ExoMars program.

  19. The binary proletariat

    OpenAIRE

    Bolt, Nate

    2000-01-01

    In the endless quest to transform itself, capitalism has spawned a new working class. The proletariat was an essential product of the industrial revolution, and the lighter, more efficient capitalism of the digital revolution has created the Binary Proletariat.

  20. Eclipsing Binary Pulsars

    CERN Document Server

    Freire, P C C

    2004-01-01

    The first eclipsing binary pulsar, PSR B1957+20, was discovered in 1987. Since then, 13 other eclipsing low-mass binary pulsars have been found, 12 of these are in globular clusters. In this paper we list the known eclipsing binary pulsars and their properties, with special attention to the eclipsing systems in 47 Tuc. We find that there are two fundamentally different groups of eclipsing binary pulsars; separated by their companion masses. The less massive systems (M_c ~ 0.02 M_sun) are a product of predictable stellar evolution in binary pulsars. The systems with more massive companions (M_c ~ 0.2 M_sun) were formed by exchange encounters in globular clusters, and for that reason are exclusive to those environments. This class of systems can be used to learn about the neutron star recycling fraction in the globular clusters actively forming pulsars. We suggest that most of these binary systems are undetectable at radio wavelengths.

  1. Binary Evolutionary Models

    CERN Document Server

    Han, Z

    2008-01-01

    In this talk, we present the general principles of binary evolution and give two examples. The first example is the formation of subdwarf B stars (sdBs) and their application to the long-standing problem of ultraviolet excess (also known as UV-upturn) in elliptical galaxies. The second is for the progenitors of type Ia supernovae (SNe Ia). We discuss the main binary interactions, i.e., stable Roche lobe overflow (RLOF) and common envelope (CE) evolution, and show evolutionary channels leading to the formation of various binary-related objects. In the first example, we show that the binary model of sdB stars of Han et al. (2002, 2003) can reproduce field sdB stars and their counterparts, extreme horizontal branch (EHB) stars, in globular clusters. By applying the binary model to the study of evolutionary population synthesis, we have obtained an ``a priori'' model for the UV-upturn of elliptical galaxies and showed that the UV-upturn is most likely resulted from binary interactions. This has major implications...

  2. THE SYNERGY OF DIRECT IMAGING AND ASTROMETRY FOR ORBIT DETERMINATION OF EXO-EARTHS

    International Nuclear Information System (INIS)

    The holy grail of exoplanet searches is an exo-Earth, an Earth mass planet in the habitable zone (HZ) around a nearby star. Mass is one of the most important characteristics of a planet and can only be measured by observing the motion of the star around the planet-star center of gravity. The planet's orbit can be measured either by imaging the planet at multiple epochs or by measuring the position of the star at multiple epochs by space-based astrometry. The measurement of an exoplanet's orbit by direct imaging is complicated by a number of factors. One is the inner working angle (IWA). A space coronagraph or interferometer imaging an exo-Earth can separate the light from the planet from the light from the star only when the star-planet separation is larger than the IWA. Second, the apparent brightness of a planet depends on the orbital phase. A single image of a planet cannot tell us whether the planet is in the HZ or distinguish whether it is an exo-Earth or a Neptune-mass planet. Third is the confusion that may arise from the presence of multiple planets. With two images of a multiple planet system, it is not possible to assign a dot to a planet based only on the photometry and color of the planet. Finally, the planet-star contrast must exceed a certain minimum value in order for the planet to be detected. The planet may be unobservable even when it is outside the IWA, such as when the bright side of the planet is facing away from us in a 'crescent' phase. In this paper we address the question: 'Can a prior astrometric mission that can identify which stars have Earth-like planets significantly improve the science yield of a mission to image exo-Earths?' In the case of the Occulting Ozone Observatory, a small external occulter mission that cannot measure spectra, we find that the occulter mission could confirm the orbits of ∼4 to ∼5 times as many exo-Earths if an astrometric mission preceded it to identify which stars had such planets. In the case of an

  3. Effects of exo-electron emission from MgO thin film on statistical delay of glow discharge of ac-PDP

    International Nuclear Information System (INIS)

    Relationship between exo-electron emission currents and statistical delay of glow discharges of ac-PDP was investigated by measuring exo-electron currents. The currents were measured as a function of time and doping elements. The measured results indicated that the exo-electron currents decrease exponentially with time, while the statistical delay increases with time. The results demonstrate that the statistical discharge delay is inversely proportional to the currents of exo-electron emission from MgO film in a time interval of 1 to 10 ms.

  4. Revealing Exo-Zody and Exo-Planets from Solar System Dust Measurements: ALADDIN-2 for the Solar Power Sail Mission

    Science.gov (United States)

    Yano, Hajime; Hirai, Takayuki

    2016-07-01

    The dust structure of our Solar System provides a benchmark information of dust disks of other exo-planetary systems in general, just like the Sun as the closest main sequence G-star that we can study with the most details. Heliocentric dust distributions and gravitational and orbital interactions with planets such as mean motion resonances (MMRs) of dust flux of our Solar System are what we can transfer the knowledge of our Solar System dust apply to infer anisotropic exo-zodiacal brightness, or spatial structures within a exo-planetary dust disks with information about potentially embedded planets inside. In the coming era of disk resolved observations by ALMA, TMT and other new telescopes, we will be able to apply what we find in the Solar System to the rest of planetary systems. In 2010-11, the IKAROS solar sail spacecraft carried the ALADDIN large area dust detector array to study large meteoroids between the Earth and Venus orbits. Yano et al. directly detected both the Earth's and Venus' MMRs dust structures, being consistent with numerical simulations that predict the existence of such local enhancements of dust distribution around these terrestrial planets, as well as Neptune. JAXA's Solar Power Sail mission plans to carry even larger dust detector inherited the technology onboard IKAROS, namely ALADDIN-2 in order to search for such MMRs in the Mars and Jupiter orbits, as predicted by Kuchner et al.(2000), in addition to make a continuous measurement of large dust flux from 1.0 to 5.2 AU crossing the main asteroid belt up to Jupiter Trojan region. It is also noted that recent reanalysis of the Pioneer 10 and 11 photo polarimeter data suggests a small enhancement of the brightness towards the anti-solar direction near Jupiter the largest planet of our Solar System, implying a possible existence of a dust belt related to the planet. The spatial density of dust particles directly measured by the ALADDIN-2 will provide a more conclusive and direct proof due to

  5. Binary Neutron Star Mergers

    Directory of Open Access Journals (Sweden)

    Joshua A. Faber

    2012-07-01

    Full Text Available We review the current status of studies of the coalescence of binary neutron star systems. We begin with a discussion of the formation channels of merging binaries and we discuss the most recent theoretical predictions for merger rates. Next, we turn to the quasi-equilibrium formalisms that are used to study binaries prior to the merger phase and to generate initial data for fully dynamical simulations. The quasi-equilibrium approximation has played a key role in developing our understanding of the physics of binary coalescence and, in particular, of the orbital instability processes that can drive binaries to merger at the end of their lifetimes. We then turn to the numerical techniques used in dynamical simulations, including relativistic formalisms, (magneto-hydrodynamics, gravitational-wave extraction techniques, and nuclear microphysics treatments. This is followed by a summary of the simulations performed across the field to date, including the most recent results from both fully relativistic and microphysically detailed simulations. Finally, we discuss the likely directions for the field as we transition from the first to the second generation of gravitational-wave interferometers and while supercomputers reach the petascale frontier.

  6. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees. For...... all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  7. The Use of ExoSeal Vascular Closure Device for Direct Antegrade Superficial Femoral Artery Puncture Site Hemostasis

    International Nuclear Information System (INIS)

    PurposeThis study was designed to assess the efficacy and safety of the ExoSeal vascular closure device (VCD) to achieve hemostasis in antegrade access of the superficial femoral artery (SFA).MethodsWe retrospectively reviewed the outcome of ExoSeal VCD used for hemostasis in 110 accesses to the SFA in 93 patients between July 2011 and July 2013. All patients had patent proximal SFA based on computer tomography angiography or ultrasound duplex. Arterial calcifications at puncture site were graded using fluoroscopy. The SFA was accessed in an antegrade fashion with ultrasound or fluoroscopic guidance. In all patients, 5–7F vascular sheaths were used. The ExoSeal VCD was applied to achieve hemostasis at the end of the procedure. All patients were clinically examined and had ultrasound duplex exam for any puncture site complications during the 24 h postprocedure.ResultsIn all procedures, the ExoSeal was applied successfully. We did not encounter any device-related technical failure. There were four major complications in four patients (3.6 %): three pseudoaneurysms, which were treated with direct thrombin injection, and one hematoma, which necessitated transfusion of two blood units. All patients with complications were treated with anticoagulation preprocedure or received thrombolytic therapy.ConclusionsThe ExoSeal VCD can be safely used for antegrade puncture of the SFA, with a high procedural success rate (100 %) and a low rate of access site complications (3.6 %)

  8. The Use of ExoSeal Vascular Closure Device for Direct Antegrade Superficial Femoral Artery Puncture Site Hemostasis

    Energy Technology Data Exchange (ETDEWEB)

    Rimon, Uri, E-mail: rimonu@sheba.health.gov.il; Khaitovich, Boris, E-mail: borislena@012.net.il [Tel-Aviv University, Diagnostic and Interventional Imaging Department, Chaim Sheba Medical Center, Tel-Hashomer, Affiliated to the Sackler School of Medicine (Israel); Yakubovich, Dmitry, E-mail: Dmitry.Yakubovitch@sheba.health.gov.il [Tel-Aviv University, Vascular Surgery Department, Chaim Sheba Medical Center, Tel-Hashomer, Affiliated to the Sackler School of Medicine (Israel); Bensaid, Paul, E-mail: paulbensaid@hotmail.com; Golan, Gil, E-mail: gilgolan201@gmail.com [Tel-Aviv University, Diagnostic and Interventional Imaging Department, Chaim Sheba Medical Center, Tel-Hashomer, Affiliated to the Sackler School of Medicine (Israel); Silverberg, Daniel, E-mail: Daniel.Silverberg@sheba.health.gov.il [Tel-Aviv University, Vascular Surgery Department, Chaim Sheba Medical Center, Tel-Hashomer, Affiliated to the Sackler School of Medicine (Israel)

    2015-06-15

    PurposeThis study was designed to assess the efficacy and safety of the ExoSeal vascular closure device (VCD) to achieve hemostasis in antegrade access of the superficial femoral artery (SFA).MethodsWe retrospectively reviewed the outcome of ExoSeal VCD used for hemostasis in 110 accesses to the SFA in 93 patients between July 2011 and July 2013. All patients had patent proximal SFA based on computer tomography angiography or ultrasound duplex. Arterial calcifications at puncture site were graded using fluoroscopy. The SFA was accessed in an antegrade fashion with ultrasound or fluoroscopic guidance. In all patients, 5–7F vascular sheaths were used. The ExoSeal VCD was applied to achieve hemostasis at the end of the procedure. All patients were clinically examined and had ultrasound duplex exam for any puncture site complications during the 24 h postprocedure.ResultsIn all procedures, the ExoSeal was applied successfully. We did not encounter any device-related technical failure. There were four major complications in four patients (3.6 %): three pseudoaneurysms, which were treated with direct thrombin injection, and one hematoma, which necessitated transfusion of two blood units. All patients with complications were treated with anticoagulation preprocedure or received thrombolytic therapy.ConclusionsThe ExoSeal VCD can be safely used for antegrade puncture of the SFA, with a high procedural success rate (100 %) and a low rate of access site complications (3.6 %)

  9. Binary Popldation Synthcsis Study

    Institute of Scientific and Technical Information of China (English)

    HAN Zhanwen

    2011-01-01

    Binary population synthesis (BPS), an approach to evolving millions of stars (including binaries) simultaneously, plays a crucial role in our understanding of stellar physics, the structure and evolution of galaxies, and cosmology. We proposed and developed a BPS approach, and used it to investigate the formation of many peculiar stars such as hot subdwarf stars, progenitors of type la supernovae, barium stars, CH stars, planetary nebulae, double white dwarfs, blue stragglers, contact binaries, etc. We also established an evolution population synthesis (EPS) model, the Yunnan Model, which takes into account binary interactions for the first time. We applied our model for the origin of hot subdwarf stars in the study of elliptical galaxies and explained their far-UV radiation.

  10. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Lorimer Duncan R.

    2008-11-01

    Full Text Available We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5M_⊙, a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric (e = 0.44 orbit around an unevolved companion.

  11. Binary and Millisecond Pulsars

    CERN Document Server

    Lorimer, D R

    2008-01-01

    We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5 solar masses, a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric (e=0.44) orbit around an unevolved companion.

  12. Hypervelocity binary stars: smoking gun of massive binary black holes

    CERN Document Server

    Lu, Youjun; Lin, D N C

    2007-01-01

    The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black hole. In this paper, we demonstrate that binary stars can be ejected out of the Galactic center with velocities up to 10^3 km/s, while preserving their integrity, through interactions with a massive binary black hole. Binary stars are unlikely to attain such high velocities via scattering by a single massive black hole or through any other mechanisms. Based on the above theoretical prediction, we propose a search for binary systems among the hypervelocity stars. Discovery of hypervelocity binary stars, even one, is a definitive evidence of the existence of a massive binary black hole in the Galactic center.

  13. Milli-arcsecond Binaries

    CERN Document Server

    Torres, R M; Mioduszewki, A; Rodríguez, L F

    2008-01-01

    As part of an astrometric program, we have used the Very Long Baseline Array to measure the trigonometric parallax of several young stars in the Taurus and Ophiuchus star-forming regions with great accuracy. Additionally, we have obtained an unprecedented sample of high-resolution (~ 1 mas) images of several young stellar systems. These images revealed that about 70% of the stars in our sample are very tight binary stars (with separations of a few mas). Since it is highly unlikely that 70% of all stars are such tight binaries, we argue that selection effects are at work.

  14. Binary Cumulant Varieties

    CERN Document Server

    Sturmfels, Bernd

    2011-01-01

    Algebraic statistics for binary random variables is concerned with highly structured algebraic varieties in the space of 2x2x...x2-tensors. We demonstrate the advantages of representing such varieties in the coordinate system of binary cumulants. Our primary focus lies on hidden subset models. Parametrizations and implicit equations in cumulants are derived for hyperdeterminants, for secant and tangential varieties of Segre varieties, and for certain context-specific independence models. Extending work of Rota and collaborators, we explore the polynomial inequalities satisfied by cumulants.

  15. Inspiring People to Participate in the NameExoWorlds Contest

    Science.gov (United States)

    Usuda-Sato, Kumiko; Iizuka, Reiko; Yamaoka, Hitoshi; Agata, Hidehiko

    2015-08-01

    In July 2014 IAU announced the NameExoWorlds contest to give popular names to the selected exoplanets along with their host stars. It is an excellent chance for amateur clubs, school groups, and other non-profit organizations to get interested in the latest astronomical research of exoplanets by participating in the international contest.In Japan the NameExoWorlds Working Group (WG) was organized at the Astronomical Consortium of Japan (ACJ). ACJ consists of astronomical organizations such as Astronomical Society of Japan (ASJ), National Astronomical Observatory of Japan (NAOJ), Japan Aerospace Exploration Agency (JAXA), Japanese Society for Education and Popularization of Astronomy (JSEPA), Japan Planetarium Association (JPA), Japan Public Observatory Society (JAPOS), and Japan Amateur Astronomers Association (JAAA). The WG was led by volunteers from JSEPA and JAAA.We, the WG members, developed the exoplanet.jp website to provide useful information to the public in Japanese language with useful contents: translations of the contest schedule and how to register, how to observe exoplanets, recommended planetary systems by Japanese researchers, downloadable photos and posters, and so on.We also sent updates frequently by e-mail newsletters and twitter so that a lot of Japanese groups feel easy and confortable to register and to vote for the 20 planetary systems they wish to name. Before the deadline of voting for 20 planetary systems on February 15, 2015, 127 Japanese groups completed registration, which account for about one third of the 388 registered groups in the world (as of Feb 15).In our presentation we will report our approaches to inspire Japanese people to participate in the worldwide NameExoWorlds contest.

  16. Charge recombination processes in minerals studied using optically stimulated luminescence and time-resolved exo-electrons

    DEFF Research Database (Denmark)

    Tsukamoto, Sumiko; Murray, Andrew; Ankjærgaard, Christina;

    2010-01-01

    A time-resolved optically stimulated exo-electron (TR-OSE) measurement system has been developed using a Photon Timer attached to a gas-flow semi-proportional pancake electron detector within a Risø TL/OSL reader. The decay rate of the exo-electron emission after the stimulation pulse depends on...... instantaneous electron concentration in the conduction band. In this study, TR-OSE and time-resolved optically stimulated luminescence (TR-OSL) were measured for the first time using quartz, K-feldspar and NaCl by stimulating the samples using pulsed blue LEDs at different temperatures between 50 and 250 °C...... the probability of (1) escape of electrons into the detector gas from the conduction band by overcoming the work function of the material and (2) thermalization of electrons in the conduction band, and subsequent re-trapping/recombination. Thus, we expect the exo-electron signal to reflect the...

  17. An Optimal Energy Estimator to Reduce Correlated Noise for the EXO-200 Light Readout

    OpenAIRE

    Collaboration, EXO-200; :; Davis, C. G.; Hall, C; Albert, J. B.; Barbeau, P. S.; D. Beck; Belov, V.; Breidenbach, M.; Brunner, T.; Burenkov, A.; Cao, G. F.; Cen, W. R.; Chambers, C.; Cleveland, B.

    2016-01-01

    The energy resolution of the EXO-200 detector is limited by electronics noise in the measurement of the scintillation response. Here we present a new technique to extract optimal scintillation energy measurements for signals split across multiple channels in the presence of correlated noise. The implementation of these techniques improves the energy resolution of the detector at the neutrinoless double beta decay Q-value from $\\left[1.9641\\pm 0.0039\\right]\\%$ to $\\left[1.5820\\pm 0.0044\\right]...

  18. Ma_Miss for ExoMars mission: miniaturized imaging spectrometer for subsurface studies

    Science.gov (United States)

    De Sanctis, M. C.; Altieri, F.; Ammannito, E.; De Angelis, S.; Di Iorio, T.; Manzari, P.; Mugnuolo, R.; Soldani-Benzi, M.; Battistelli, E.; Coppo, P.; Novi, S.; Meini, M.

    2014-04-01

    The study of the Martian subsurface will provide important constraints on the nature, timing and duration of alteration and sedimentation processes on Mars, as well as on the complex interactions between the surface and the atmosphere. A Drilling system, coupled with an in situ analysis package, is installed on the ExoMars Rover to perform in situ investigations up to 2m in the Mars soil. Ma_Miss (Mars Multispectral Imager for Subsurface Studies) is a spectrometer devoted to observe the lateral wall of the borehole generated by the Drilling system [1,2]. The instrument is fully integrated with the Drill and shares its structure and electronics.

  19. Rational design, synthesis, and pharmacological evaluation of 2-azanorbornane-3-exo,5-endo-dicarboxylic acid

    DEFF Research Database (Denmark)

    Bunch, Lennart; Liljefors, Tommy; Greenwood, Jeremy R;

    2003-01-01

    The design and synthesis of conformationally restricted analogues of alpha-amino acids is an often used strategy in medicinal chemistry research. Here we present the rational design, synthesis, and pharmacological evaluation of 2-azanorbornane-3-exo,5-endo-dicarboxylic acid (1), a novel...... conformationally restricted (S)-glutamic acid (Glu) analogue intended as a mimic of the folded Glu conformation. The synthesis of 1 was completed in its racemic form in eight steps from commercially available starting materials. As a key step, the first facially selective hydroboration of a 5-methylidene[2...

  20. Determining Habitability: Which exoEarths should we search for life?

    OpenAIRE

    Horner, J.; Jones, B. W.

    2010-01-01

    Within the next few years, the first Earth-mass planets will be discovered around other stars. Some of those worlds will certainly lie within the classical "habitable zone" of their parent stars, and we will quickly move from knowing of no exoEarths to knowing many. For the first time, we will be in a position to carry out a detailed search for the first evidence of life beyond our Solar System. However, such observations will be hugely taxing and time consuming to perform, and it is almost c...

  1. Selecting a landing site for the ExoMars 2018 mission

    Science.gov (United States)

    Vago, J. L.; Lorenzoni, L.; Calantropio, F.; Zashchirinskiy, A. M.

    2015-12-01

    The European Space Agency (ESA) and Roscosmos ExoMars 2018 joint mission is planned to deliver a rover and a surface platform to the surface of Mars. The rover's payloads are designed to search for signs of life; those of the surface platform are to conduct environmental and geophysical measurements. A necessary condition for meeting these objectives is to land safely at a scientifically appropriate location. This article describes the procedure followed by the two agencies to select a suitable landing site for the mission.

  2. An Optimal Energy Estimator to Reduce Correlated Noise for the EXO-200 Light Readout

    CERN Document Server

    :,; Hall, C; Albert, J B; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Cen, W R; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dilling, J; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Feyzbakhsh, S; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hughes, M; Jewell, M J; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krücken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Njoya, O; Nelson, R; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Retière, F; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2016-01-01

    The energy resolution of the EXO-200 detector is limited by electronics noise in the measurement of the scintillation response. Here we present a new technique to extract optimal scintillation energy measurements for signals split across multiple channels in the presence of correlated noise. The implementation of these techniques improves the energy resolution of the detector at the neutrinoless double beta decay Q-value from $\\left[1.9641\\pm 0.0039\\right]\\%$ to $\\left[1.5820\\pm 0.0044\\right]\\%$.

  3. Formation of binary radio pulsars

    International Nuclear Information System (INIS)

    In the framework of the standard scenario of the evolution of massive binary stars a study is made of the formation of final binary systems in which at least one of the components is a neutron star. It is found that about every fortieth radio pulsar must be a member of a close binary system. This is confirmed by observations. Radio pulsars are not formed in wide binary systems, possibly because of the very slow rotation of the presupernova stars

  4. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  5. Equational binary decision diagrams

    NARCIS (Netherlands)

    Groote, J.F.; Pol, J.C. van de

    2000-01-01

    We incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and tautology checkin

  6. Modeling the Exo-Brake and the Development of Strategies for De-Orbit Drag Modulation

    Science.gov (United States)

    Murbach, M. S.; Papadopoulos, P.; Glass, C.; Dwyer-Cianciolo, A.; Powell, R. W.; Dutta, S.; Guarneros-Luna, A.; Tanner, F. A.; Dono, A.

    2016-01-01

    The Exo-Brake is a simple, non-propulsive means of de-orbiting small payloads from orbital platforms such as the International Space Station (ISS). Two de-orbiting experiments with fixed surface area Exo-Brakes have been successfully conducted in the last two years on the TechEdSat-3 and -4 nano-satellite missions. The development of the free molecular flow aerodynamic data-base is presented in terms of angle of attack, projected front surface area variation, and altitude. Altitudes are considered ranging from the 400km ISS jettison altitude to 90km. Trajectory tools are then used to predict de-orbit/entry corridors with the inclusion of the key atmospheric and geomagnetic uncertainties. Control system strategies are discussed which will be applied to the next two planned TechEdSat-5 and -6 nano-satellite missions - thus increasing the targeting accuracy at the Von Karman altitude through the proposed drag modulation technique.

  7. ExoCat-1: The Nearby Stellar Systems Catalog for Exoplanet Imaging Missions

    CERN Document Server

    Turnbull, Margaret C

    2015-01-01

    We present the first version of a Nearby Stellar Systems Catalog for Exoplanet Imaging Missions (dubbed by the direct imaging community as "ExoCat") for use in exoplanet direct imaging mission planning. This version, ExoCat-1, includes 2347 stars taken from the Hipparcos Catalogue with measured parallaxes > 33.33 mas (corresponding to a distance of 30 pc). This sample is nearly complete down to V=8, corresponding to stars brighter than ~0.5 solar luminosities (late G-/early K-type dwarf stars at the 30 pc distance limit). For each star we provide astrometry (including Equatorial and Galactic coordinates, parallax, and proper motions), Johnson B and V magnitudes (converted from Hipparcos or Tycho data or taken from the literature), and Ks-band magnitudes from 2MASS (for fainter stars) or K-band magnitudes taken from the literature and converted to 2MASS Ks magnitudes (for bright stars). Using these data we estimate stellar luminosity, effective temperature, stellar radius (in solar and angular units), Earth-eq...

  8. The electrical ground support equipment for the ExoMars 2016 DREAMS scientific instrument

    Science.gov (United States)

    Molfese, C.; Schipani, P.; Marty, L.; Esposito, F.; D'Orsi, S.; Mannetta, M.; Debei, S.; Bettanini, C.; Aboudan, A.; Colombatti, G.; Mugnuolo, R.; Marchetti, E.; Pirrotta, S.

    2014-08-01

    This paper describes the Electrical Ground Support Equipment (EGSE) of the Dust characterization, Risk assessment, and Environment Analyser on the Martian Surface (DREAMS) scientific instrument, an autonomous surface payload package to be accommodated on the Entry, Descendent and landing Module (EDM) of the ExoMars 2016 European Space Agency (ESA) mission. DREAMS will perform several kinds of measurements, such as the solar irradiance with different optical detectors in the UVA band (315-400nm), NIR band (700-1100nm) and in "total luminosity" (200 -1100 nm). It will also measure environmental parameters such as the intensity of the electric field, temperature, pressure, humidity, speed and direction of the wind. The EGSE is built to control the instrument and manage the data acquisition before the integration of DREAMS within the Entry, Descendent and landing Module (EDM) and then to retrieve data from the EDM Central Checkout System (CCS), after the integration. Finally it will support also the data management during mission operations. The EGSE is based on commercial off-the-shelf components and runs custom software. It provides power supply and simulates the spacecraft, allowing the exchange of commands and telemetry according to the protocol defined by the spacecraft prime contractor. This paper describes the architecture of the system, as well as its functionalities to test the DREAMS instrument during all development activities before the ExoMars 2016 launch.

  9. Manipulation and Characterization of Alginate Exo polysaccharides produced by Azotobacter Vinelandii

    International Nuclear Information System (INIS)

    Exo polysaccharides (EPS) have been found in a wide range of applications in food industry and in the biomedical field. In the present study, the effect of nutritional factors (carbon and nitrogen sources) and gamma irradiations on alginate production by Azotobacter vinelandii was investigated. To understand the direct and indirect relations among these variables, a two way factorial design experiment was set up. At low concentration of carbon source (≤ 20 g/l), the alginate yield was influenced by the type of nitrogen substrate and C/N ratio, whereas the role of these factors on alginate production was minimized at high concentration of carbon source (> 20 g/l). Batch fermentation of alginate exo polysaccharides was manipulated by maintaining the ph value of the cultures at 7 along the incubation period and reducing the agitation speed to 100 rpm after 24 h at the time of inoculation. This process succeeded to increase the alginate yield exponentially with time by 50%. Exposing A. vinelandii cells to gamma irradiation at dose level 0.5 kGy decreased their activity to synthesis alginate by 44%. The produced alginate was characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) and differential scanning calorimeter (DSC).

  10. Expression and Characterization of Hyperthermostable Exo-polygalacturonase TtGH28 from Thermotoga thermophilus.

    Science.gov (United States)

    Wagschal, Kurt; Rose Stoller, J; Chan, Victor J; Lee, Charles C; Grigorescu, Arabela A; Jordan, Douglas B

    2016-07-01

    D-galacturonic acid is a potential platform chemical comprising the principal component of pectin in the citrus processing waste stream. Several enzyme activities are required for the enzymatic production of galacturonic acid from pectin, including exo- and endo-polygalacturonases. The gene TtGH28 encoding a putative GH28 polygalacturonase from Pseudothermotoga thermarum DSM 5069 (Theth_0397, NCBI# AEH50492.1) was synthesized, expressed in Escherichia coli, and characterized. Alignment of the amino acid sequence of gene product TtGH28 with other GH28 proteins whose structures and details of their catalytic mechanism have been elucidated shows that three catalytic Asp residues and several other key active site residues are strictly conserved. Purified TtGH28 was dimeric and hyperthermostable, with K t (0.5)  = 86.3 °C. Kinetic parameters for activity on digalacturonic acid, trigalacturonic acid, and polygalacturonic acid were obtained. No substrate inhibition was observed for polygalacturonate, while the K si values for the oligogalacturonides were in the low mM range, and K i for product galacturonic acid was in the low μM range. Kinetic modeling of the progress of reaction showed that the enzyme is both fully exo- and fully non-processional. PMID:27209035

  11. Optimization of Liquid Fermentation Process for Improved Exo-Polysaccharides Production by Kombucha ZJU1

    Directory of Open Access Journals (Sweden)

    Yan Wu

    2013-02-01

    Full Text Available In order to improve exo-polysaccharides production by Kombucha ZJU1, the optimization of liquid fermentation process for cell growth and Exo-Polysaccharide (EPS production by Kombucha ZJU1 was conducted with Response Surface Methodology (RSM. A Fractional Factorial Design (FFD and Central Composite Design (CCD were applied to optimize the main factors that affect EPS production during fermentation. Both the concentration of brown sugar and inoculation level significantly affected EPS production by Kombucha ZJU1 through FFD experiment. The optimized fermentation process was derived from the predicted model using central composite design as follows: 280 g/L brown sugar, 4 g/L Pu-erh tea, 1 g/L KH2PO4 and 1 g/L (NH42 SO4 initial pH unadjusted, the culture medium was inoculated with 1.95% (v/v Kombucha ZJU1, the cell age was 5 days, then incubated at a temperature of 30±1°C for 6 days on the rotary shaker. The predicted maximal EPS concentration was 2.66 g/L using this optimized fermentation process, which was of value to further work.

  12. Crystallization of selenomethionyl exo-β-1,3-galactanase from the basidiomycete Phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    Selenomethionyl exo-β-1,3-galactanase from P. chrysosporium K-3 produced in Pichia pastoris was crystallized. The crystals diffracted to a resolution of 1.8 Å and belonged to space group P21. Exo-β-1,3-galactanase from Phanerochaete chrysosporium (Pc1,3Gal43A) consists of a glycoside hydrolase family 43 catalytic domain and a substrate-binding domain that belongs to carbohydrate-binding module family 35. It catalyzes the hydrolysis of β-1,3-galactan, which is the backbone of the arabinogalactan proteins; the C-terminal carbohydrate-binding module family 35 domain increases the local concentration of the enzyme around β-1,3-galactan by its high affinity for the substrate. To enable phase determination using the multiwavelength anomalous dispersion method, selenomethionyl Pc1,3Gal43A was crystallized at 298 K using the hanging-drop vapour-diffusion method. The presence of selenium in the crystals was confirmed from the X-ray absorption spectrum. The crystals belonged to space group P21 and diffracted to 1.8 Å resolution

  13. Oxia Planum: a suitable landing site for ExoMars 2018 Rover

    Science.gov (United States)

    Quantin, C.; Carter, J.; Thollot, P.; Broyer, J.; Lozac'h, L.; Davis, J.; Grindrod, P.; Pajola, M.; Baratti, E.; Rossato, S.; Allemand, P.; Bultel, B.; Leyrat, C.; Fernando, J.; Ody, A.

    2015-10-01

    We suggest the landing of ExoMars in Oxia Planum between 16° and 19° of latitude north and -23° to -28° of eastern longitude, and below -2 km of MOLA elevation. This region exhibits one of the widest Mg/Fe phyllosilicates exposures as mapped globally with OMEGA and with CRISM multispectral data. The outcrop of Mg/Fe phyllosilicates is so wide that several potential landing ellipses (19 x 110 km) fitting the engineering constraints is possible. The exposed terrains are 4 Ga old (Hartmann's age system) and have undergone intense erosional processes until 3.6 Ga. The region also reveals fluvial related morphologies such as valleys and a delta fan attesting the water-related history of this region. Moreover, the region is current under erosion so that the exposition age of the fresher phyllosilicate rich surfaces is younger than 100 My attesting the potential preservation of putative biosignature. This proposed site fulfills ExoMars objectives.

  14. The Synergy of Direct Imaging and Astrometry for Orbit Determination of exo-Earths

    CERN Document Server

    Shao, Michael; Pan, Xiaopei

    2010-01-01

    The holy grail of exoplanet searches is an exo-Earth, an Earth mass planet in the habitable zone around a nearby star. Mass is the most important parameter of a planet and can only be measured by observing the motion of the star around the planet-star center of mass. A single image of a planet, however, does not provide evidence that the planet is Earth mass or that it is in a habitable zone orbit. The planet's orbit, however, can be measured either by imaging the planet at multiple epochs or by measuring the position of the star at multiple epochs by space-based astrometry. The measurement of an exo-planet's orbit by direct imaging is complicated by a number of factors: (1) the inner working angle (IWA); (2) the apparent brightness of the planet depending on the orbital phase; (3) confusion arising from the presence of multiple planets; and (4) the planet-star contrast. In this paper we address the question: "Can a prior astrometric mission that can identify which stars have Earthlike planets significantly i...

  15. ExoHab Pilot Project & Field Tests for Moon-Mars Human Laboratories

    Science.gov (United States)

    Foing, Bernard

    2010-05-01

    We studied concepts for a minimal Moon-Mars habitat, in focussing on the system aspects and coordinating every different part as part an evolving architecture. We validated experimentally the Habitat and Laboratory ExoHab concept constraints during EuroGeoMars campaign in Utah desert research station (from 24 Jan. to 28 Feb. 2009) and EuroMoonMars/DOMMEX campaigns in Nov 2009 and February-April 2010. We discuss from the ILEWG ExoHab concept studies and field simulations the specifics of human exploration, with focus on habitability and human performance. In the ExoHab pilot concept project (supported by ILEWG, ESA NASA), we justify the case for a scientific and exploration outpost allowing experiments, sample analysis in laboratory (relevant to the origin and evolution of planets and life, geophysical and geo-chemical studies, astrobiology and life sciences, observation sciences, technology demonstration, resource utilisation, human exploration and settlement). In this modular concept, we consider various infra structure elements: core habitat, Extra Vehicular activity (EVA), crew mobility, energy supply, recycling module, communication, green house and food production, operations. We review some studies space agencies' architecture proposals, with landers, orbiters, rovers, habitats, surface operations and protocols. We focus on the easiest and the soonest way in settling a minimal base immediately operational in scientific experimentation and exploration, but not immediately autonomous. Through a modular concept, this outpost will be possibly evolved into a long duration or permanent base. We will analyse the possibilities of settling such a minimal base by means of the current and near term propulsion technology, as a full Ariane 5 ME carrying 1.7 T of gross payload to the surface of the Moon (Integrated Exploration Study, ESA ESTEC [1,2]). The low solar rays incidence may permit having ice in deep craters, which will be beneficial for the evolution of the

  16. Binary MEMS gas sensors

    International Nuclear Information System (INIS)

    A novel sensing mechanism for electrostatic MEMS that employs static bifurcation-based sensing and binary detection is demonstrated. It is implemented as an ethanol vapour sensor that exploits the static pull-in bifurcation. Sensor detection of 5 ppm of ethanol vapour in dry nitrogen, equivalent to a detectable mass of 165 pg, is experimentally demonstrated. Sensor robustness to external disturbances is also demonstrated. A closed-form expression for the sensitivity of statically detected electrostatic MEMS sensors is derived. It is shown that the sensitivity of static bifurcation-based binary electrostatic MEMS sensors represents an upper bound on the sensitivity of static detection for given sensor dimensions and material properties. (paper)

  17. Binary Tetrahedral Flavor Symmetry

    CERN Document Server

    Eby, David A

    2013-01-01

    A study of the T' Model and its variants utilizing Binary Tetrahedral Flavor Symmetry. We begin with a description of the historical context and motivations for this theory, together with some conceptual background for added clarity, and an account of our theory's inception in previous works. Our model endeavors to bridge two categories of particles, leptons and quarks, a unification made possible by the inclusion of additional Higgs particles, shared between the two fermion sectors and creating a single coherent system. This is achieved through the use of the Binary Tetrahedral symmetry group and an investigation of the Tribimaximal symmetry evidenced by neutrinos. Our work details perturbations and extensions of this T' Model as we apply our framework to neutrino mixing, quark mixing, unification, and dark matter. Where possible, we evaluate model predictions against experimental results and find excellent matching with the atmospheric and reactor neutrino mixing angles, an accurate prediction of the Cabibb...

  18. Compressing Binary Decision Diagrams

    CERN Document Server

    Hansen, Esben Rune; Tiedemann, Peter

    2008-01-01

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances.

  19. Kinetic properties of two Rhizopus exo-polygalacturonase enzymes hydrolyzing galacturonic acid oligomers using isothermal titration calorimetry

    Science.gov (United States)

    The kinetic characteristics of two Rhizopus oryzae exo-polygalacturonases acting on galacturonic acid oligomers (GalpA) were determined using isothermal titration calorimetry (ITC). RPG15 hydrolyzing (GalpA)2 demonstrated a Km of 55 uM and kcat of 10.3 s^-1^ while RPG16 was shown to have greater af...

  20. Arabidopsis Exocyst Subcomplex Containing Subunit EXO70B1 Is Involved in Autophagy-Related Transport to the Vacuole

    Czech Academy of Sciences Publication Activity Database

    Kulich, Ivan; Pečenková, Tamara; Sekereš, J.; Smetana, Ondřej; Fendrych, Matyáš; Foissner, I.; Hoftberger, M.; Žárský, Viktor

    2013-01-01

    Roč. 14, č. 11 (2013), s. 1155-1165. ISSN 1398-9219 R&D Projects: GA ČR(CZ) GAP305/11/1629 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arabidopsis * autophagy * EXO70 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.714, year: 2013

  1. [Textual research on the time of completion of XU Shuwei' books on exo-pathogenic cold diseases].

    Science.gov (United States)

    Lu, Mingxin

    2015-11-01

    Shang han bai zheng ge (Poets of Syndromes of Exo-pathogenic Cold Disease), Shang han fa wei lun (Discourse on Elucidation of Exo-pathogenic Cold Disease), Shang han jiu shi lun (90 Discourses on Exo-pathogenic Cold Disease) were the three extant books on exo-pathogenic cold disease written by Xu Shuwei among his other works of its kind. Although there were carved editions of the Yuan and Ming Dynasties, these books were gradually paid attention for citations by other physicians till the Qing Dynasty. Through comparison of its texts, it can be found that the title of Shang han bai zheng ge was mentioned in his other medical works. While Shang han fa wei lun and Shang han jiu shi lun contained some overlapping contents, some even carrying concept contradictory to each other. According to historical materials, Xu Shuwei began to write the above-mentioned 3 books in the Northern Song Dynasty. In the several early years of the Southern Song Dynasty after crossing the Yangtze River, he collected the remained manuscripts and continued to write. Among them, Shang han bai zheng ge was completed first, followed by Shang han fa wei lun, with Shang han jiu shi lun came as the last. PMID:26813319

  2. Stereoselective 6-exo radical cyclization using cis-vinyl sulfoxide: practical total synthesis of CTX3C.

    Science.gov (United States)

    Yamashita, Shuji; Ishihara, Yuuki; Morita, Hiroyuki; Uchiyama, Junichi; Takeuchi, Katsutoshi; Inoue, Masayuki; Hirama, Masahiro

    2011-03-25

    Ciguatoxins, the principal causative toxins of ciguatera seafood poisoning, are large ladder-like polycyclic ethers. We report a highly stereoselective 6-exo radical cyclization/ring-closing olefin metathesis sequence to construct the syn/trans-fused polyether system. The new method was applied to the practical synthesis of ciguatoxin CTX3C. PMID:21250701

  3. Homology of genes for exopolysaccharide synthesis in Rhizobium leguminosarum and effect of cloned exo genes on nodule formation

    International Nuclear Information System (INIS)

    A 5.4 kb BamHI fragment of Rhizobium leguminosarum (R.l.) bv. trifolii TA1 was found to carry genes involved in exopolysaccharide synthesis (exo genes). This fragment was strongly hybridized to the total DNA from DNA from R.l. bv. viciae and bv. phaseoli digested with EcoRI. No homology was found with total DNA of R. melilotic and Rhizobium sp. NGR 234. The exo genes R.l. bv. trifolii TA1 conjugally introduced into R.l. bv. viciae 1302 considerably affected the symbiosis: the nodules induced on vetch were abortive and did not fix nitrogen. On the other hand, Phaseolus beans infected with R.l. bv. trifolii exo genes formed the nitrogen-fixing nodules. It can be conduced that additional copies of exo genes introduced into wild type R.l. strains can disturb the synthesis of acidic exopolysaccharides and affect symbiosis of the plants forming indeterminate nodules, but do not affect symbiosis of the plants forming the determinate nodules. (author). 29 refs, 2 figs, 2 tabs

  4. Binary-Signal Recovery

    Science.gov (United States)

    Griebeler, Elmer L.

    2011-01-01

    Binary communication through long cables, opto-isolators, isolating transformers, or repeaters can become distorted in characteristic ways. The usual solution is to slow the communication rate, change to a different method, or improve the communication media. It would help if the characteristic distortions could be accommodated at the receiving end to ease the communication problem. The distortions come from loss of the high-frequency content, which adds slopes to the transitions from ones to zeroes and zeroes to ones. This weakens the definition of the ones and zeroes in the time domain. The other major distortion is the reduction of low frequency, which causes the voltage that defines the ones or zeroes to drift out of recognizable range. This development describes a method for recovering a binary data stream from a signal that has been subjected to a loss of both higher-frequency content and low-frequency content that is essential to define the difference between ones and zeroes. The method makes use of the frequency structure of the waveform created by the data stream, and then enhances the characteristics related to the data to reconstruct the binary switching pattern. A major issue is simplicity. The approach taken here is to take the first derivative of the signal and then feed it to a hysteresis switch. This is equivalent in practice to using a non-resonant band pass filter feeding a Schmitt trigger. Obviously, the derivative signal needs to be offset to halfway between the thresholds of the hysteresis switch, and amplified so that the derivatives reliably exceed the thresholds. A transition from a zero to a one is the most substantial, fastest plus movement of voltage, and therefore will create the largest plus first derivative pulse. Since the quiet state of the derivative is sitting between the hysteresis thresholds, the plus pulse exceeds the plus threshold, switching the hysteresis switch plus, which re-establishes the data zero to one transition

  5. Massive Black Hole Binary Evolution

    Directory of Open Access Journals (Sweden)

    Merritt David

    2005-11-01

    Full Text Available Coalescence of binary supermassive black holes (SBHs would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires that the separation between binary components first drop by a few orders of magnitude, due presumably to interaction of the binary with stars and gas in a galactic nucleus. This article reviews the observational evidence for binary SBHs and discusses how they would evolve. No completely convincing case of a bound, binary SBH has yet been found, although a handful of systems (e.g. interacting galaxies; remnants of galaxy mergers are now believed to contain two SBHs at projected separations of <~ 1kpc. N-body studies of binary evolution in gas-free galaxies have reached large enough particle numbers to reproduce the slow, “diffusive” refilling of the binary’s loss cone that is believed to characterize binary evolution in real galactic nuclei. While some of the results of these simulations - e.g. the binary hardening rate and eccentricity evolution - are strongly N-dependent, others - e.g. the “damage” inflicted by the binary on the nucleus - are not. Luminous early-type galaxies often exhibit depleted cores with masses of ~ 1-2 times the mass of their nuclear SBHs, consistent with the predictions of the binary model. Studies of the interaction of massive binaries with gas are still in their infancy, although much progress is expected in the near future. Binary coalescence has a large influence on the spins of SBHs, even for mass ratios as extreme as 10:1, and evidence of spin-flips may have been observed.

  6. Artificial Exo-Society Modeling: a New Tool for SETI Research

    Science.gov (United States)

    Gardner, James N.

    2002-01-01

    One of the newest fields of complexity research is artificial society modeling. Methodologically related to artificial life research, artificial society modeling utilizes agent-based computer simulation tools like SWARM and SUGARSCAPE developed by the Santa Fe Institute, Los Alamos National Laboratory and the Bookings Institution in an effort to introduce an unprecedented degree of rigor and quantitative sophistication into social science research. The broad aim of artificial society modeling is to begin the development of a more unified social science that embeds cultural evolutionary processes in a computational environment that simulates demographics, the transmission of culture, conflict, economics, disease, the emergence of groups and coadaptation with an environment in a bottom-up fashion. When an artificial society computer model is run, artificial societal patterns emerge from the interaction of autonomous software agents (the "inhabitants" of the artificial society). Artificial society modeling invites the interpretation of society as a distributed computational system and the interpretation of social dynamics as a specialized category of computation. Artificial society modeling techniques offer the potential of computational simulation of hypothetical alien societies in much the same way that artificial life modeling techniques offer the potential to model hypothetical exobiological phenomena. NASA recently announced its intention to begin exploring the possibility of including artificial life research within the broad portfolio of scientific fields comprised by the interdisciplinary astrobiology research endeavor. It may be appropriate for SETI researchers to likewise commence an exploration of the possible inclusion of artificial exo-society modeling within the SETI research endeavor. Artificial exo-society modeling might be particularly useful in a post-detection environment by (1) coherently organizing the set of data points derived from a detected

  7. Biclustering Sparse Binary Genomic Data

    OpenAIRE

    Van Uitert, M.; Meuleman, W.; Wessels, L. F. A.

    2008-01-01

    Genomic datasets often consist of large, binary, sparse data matrices. In such a dataset, one is often interested in finding contiguous blocks that (mostly) contain ones. This is a biclustering problem, and while many algorithms have been proposed to deal with gene expression data, only two algorithms have been proposed that specifically deal with binary matrices. None of the gene expression biclustering algorithms can handle the large number of zeros in sparse binary matrices. The two propos...

  8. Search for Majorana neutrinos with the first two years of EXO-200 data

    CERN Document Server

    :,; Auty, D J; Barbeau, P S; Beauchamp, E; Beck, D; Belov, V; Benitez-Medina, C; Bonatt, J; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Chaves, J; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, C G; Davis, J; DeVoe, R; Delaquis, S; Didberidze, T; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Hall, C; Herrin, S; Hughes, M; Jewell, M J; Jiang, X S; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Kuchenkov, A; Kumar, K S; Leonard, D S; Leonard, F; Licciardi, C; Lin, Y H; MacLellan, R; Marino, M G; Mong, B; Moore, D; Nelson, R; Odian, A; Ostrovskiy, I; Ouellet, C; Piepke, A; Pocar, A; Prescott, C Y; Rivas, A; Rowson, P C; Rozo, M P; Russell, J J; Schubert, A; Sinclair, D; Slutsky, S; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tosi, D; Twelker, K; Vogel, P; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wright, J D; Yang, L; Yen, Y -R; Zeldovich, O Ya; Zhao, Y B

    2014-01-01

    We report on new results from the EXO-200 double-beta-decay experiment with 99.8 kg$\\cdot$yr of Xe-136 exposure, representing an almost fourfold increase from earlier publications. The detector resolution at the Xe-136 double-beta-decay Q-value has been improved to $\\sigma/E=1.53%$ and the background in the $\\pm2\\sigma$ region of interest has been determined to be $(1.7\\pm0.2)\\cdot 10^{-3}$ keV$^{-1}$ kg$^{-1}$ yr$^{-1}$, consistent with previous results. Both the exposure and the background rate are among the best in the literature, resulting in a 90% CL half-life sensitivity of $1.9\\cdot10^{25}$ yr. We find no statistically significant evidence for $0\

  9. Spectroscopy of Ba and Ba$^+$ deposits in solid xenon for barium tagging in nEXO

    CERN Document Server

    Mong, B; Walton, T; Chambers, C; Craycraft, A; Benitez-Medina, C; Hall, K; Fairbank, W; Albert, J B; Auty, D J; Barbeau, P S; Basque, V; Beck, D; Breidenbach, M; Brunner, T; Cao, G F; Cleveland, B; Coon, M; Daniels, T; Daugherty, S J; DeVoe, R; Didberidze, T; Dilling, J; Dolinski, M J; Dunford, M; Fabris, L; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Heffner, M; Hughes, M; Jiang, X S; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krucken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Moore, D; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Retiere, F; Rowson, P C; Rozo, M P; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Twelker, K; Vuilleumier, J -L; Walton, J; Weber, M; Wen, L J; Wichoski, U; Yang, L; Yen, Y -R; Zhao, Y B

    2014-01-01

    Progress on a method of barium tagging for the nEXO double beta decay experiment is reported. Absorption and emission spectra for deposits of barium atoms and ions in solid xenon matrices are presented. Excitation spectra for prominent emission lines, temperature dependence and bleaching of the fluorescence reveal the existence of different matrix sites. A regular series of sharp lines observed in Ba$^+$ deposits is identified with some type of barium hydride molecule. Lower limits for the fluorescence quantum efficiency of the principal Ba emission transition are reported. Under current conditions, an image of $\\le10^4$ Ba atoms can be obtained. Prospects for imaging single Ba atoms in solid xenon are discussed.

  10. ExoMol molecular line lists - XIV: The rotation-vibration spectrum of hot SO$_2$

    CERN Document Server

    Underwood, Daniel S; Yurchenko, Sergei N; Huang, Xinchuan; Schwenke, David W; Lee, Timothy J; Clausen, Sønnik; Fateev, Alexander

    2016-01-01

    Sulphur dioxide is well-known in the atmospheres of planets and satellites, where its presence is often associated with volcanism, and in circumstellar envelopes of young and evolved stars as well as the interstellar medium. This work presents a line list of 1.3 billion $^{32}$S$^{16}$O$_2$ vibration-rotation transitions computed using an empirically-adjusted potential energy surface and an ab initio dipole moment surface. The list gives complete coverage up to 8000 cm$^{-1}$ (wavelengths longer than 1.25 $\\mu$m) for temperatures below 2000 K. Infrared absorption cross sections are recorded at 300 and 500 C are used to validated the resulting ExoAmes line list. The line list is made available in electronic form as supplementary data to this article and at www.exomol.com.

  11. ExoMol molecular line lists - XIV: The rotation-vibration spectrum of hot SO2

    Science.gov (United States)

    Underwood, Daniel S.; Tennyson, Jonathan; Yurchenko, Sergei N.; Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.; Clausen, Sønnik; Fateev, Alexander

    2016-04-01

    Sulphur dioxide is well-known in the atmospheres of planets and satellites, where its presence is often associated with volcanism, and in circumstellar envelopes of young and evolved stars as well as the interstellar medium. This work presents a line list of 1.3 billion 32S16O2 vibration-rotation transitions computed using an empirically-adjusted potential energy surface and an ab initio dipole moment surface. The list gives complete coverage up to 8000 cm-1 (wavelengths longer than 1.25 μm) for temperatures below 2000 K. Infrared absorption cross sections are recorded at 300 and 500 C are used to validated the resulting ExoAmes line list. The line list is made available in electronic form as supplementary data to this article and at www.exomol.com.

  12. First Search for Lorentz and CPT Violation in Double Beta Decay with EXO-200

    CERN Document Server

    :,; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, C G; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Díaz, J S; Didberidze, T; Dilling, J; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feyzbkhsh, S; Feldmeier, W; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Homiller, S; Hughes, M; Jewell, M J; Jiang, X S; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krücken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Nelson, R; Njoya, O; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Retiére, F; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Vogel, P; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2016-01-01

    A search for Lorentz- and CPT-violating signals in the double beta decay spectrum of $^{136}$Xe has been performed using an exposure of 100 kg$\\cdot$yr with the EXO-200 detector. No significant evidence of the spectral modification due to isotropic Lorentz-violation was found, and a two-sided limit of $-2.65 \\times 10^{-5 } \\; \\textrm{GeV} < \\mathring{a}^{(3)}_{\\text{of}} < 7.60 \\times 10^{-6} \\; \\textrm{GeV}$ is placed on the relevant coefficient within the Standard-Model Extension (SME). This is the first experimental study of the effect of the SME-defined oscillation-free and momentum-independent neutrino coupling operator on the double beta decay process.

  13. First Search for Lorentz and CPT Violation in Double Beta Decay with EXO-200

    CERN Document Server

    Kaufman, L J

    2016-01-01

    This proceedings contribution reports the first experimental search for Lorentz- and CPT-violating signals specifically studying the effect of the Standard-Model Extension (SME) oscillation-free momentum-independent neutrino coupling operator in the double beta decay process. The search has been performed using an exposure of 100 kg yr of $^{136}$Xe with the EXO-200 detector. No significant evidence of the spectral modification due to isotropic Lorentz violation was found. A two-sided limit of $-2.65 \\times 10^{-5}$ GeV $<$ $\\mathring{a}_{\\mathrm{of}}^{(3)}$ $< 7.60 \\times 10^{-6}$ GeV (90% C.L.) is placed on the relevant coefficient within the SME.

  14. Design of a star, planet and exo-zodiacal cloud simulator for the nulling testbench PERSEE

    Science.gov (United States)

    Hénault, François; Girard, Paul; Marcotto, Aurelie; Mauclert, Nicolas; Bailet, Christophe; Lopez, Bruno; Millour, Florentin; Rabbia, Yves; Roussel, Alain; Barillot, Marc; Lozi, Julien; Cassaing, Frederic; Houairi, Kamel; Sorrente, Beatrice; Montri, Joseph; Lhome, Emilie; Reess, Jean-Michel; Pham, Laurie; Buey, Jean-Tristan; Coudé du Foresto, Vincent; Jacquinod, Sophie; Ollivier, Marc; Le Duigou, Jean-Michel

    2011-10-01

    On-going developments on the PERSEE nulling testbench include the realization of a focal plane simulator featuring one central star, an extra-solar planet orbiting around it, and an Exo-Zodiacal Cloud (EZC) surrounding the observed stellar system. PERSEE (Pégase Experiment for Research and Stabilization of Extreme Extinction) is a laboratory testbench jointly developed by a Consortium of six French institutes and companies, incorporating Observatoire de la Côte d'Azur (OCA) who is in charge of the manufacturing and procurement of the future Star and Planet Simulator (SPS). In this communication is presented a complete description of the SPS, including general requirements, techniques employed for simulating the observed planet and EZC, opto-mechanical design and expected performance. The current status of the SPS activities is summarized in the conclusion, pending final integration on the PERSEE test bench in September 2011.

  15. ExoMol molecular line lists - XIV. The rotation-vibration spectrum of hot SO2

    Science.gov (United States)

    Underwood, Daniel S.; Tennyson, Jonathan; Yurchenko, Sergei N.; Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.; Clausen, Sønnik; Fateev, Alexander

    2016-07-01

    Sulphur dioxide is well-known in the atmospheres of planets and satellites, where its presence is often associated with volcanism, and in circumstellar envelopes of young and evolved stars as well as the interstellar medium. This work presents a line list of 1.3 billion 32S16O2 vibration-rotation transitions computed using an empirically adjusted potential energy surface and an ab initio dipole moment surface. The list gives complete coverage up to 8000 cm-1 (wavelengths longer than 1.25 μm) for temperatures below 2000 K. Infrared absorption cross-sections are recorded at 300 and 500 C are used to validated the resulting ExoAmes line list. The line list is made available in electronic form as supplementary data to this article and at www.exomol.com.

  16. Exo-buccal dental radiology - Radiation protection: medical sheet ED 4250

    International Nuclear Information System (INIS)

    This document presents the various aspects and measures related to radiation protection when performing exo-buccal examinations (by either panoramic radiography or by volume tomography). It presents the concerned personnel, describes the operational process of snapshot taking, indicates the associated hazards and the risk related to ionizing radiation, and describes how the risk is to be assessed and how exposure levels are to be determined (elements of risk assessment, delimitation of controlled and monitored areas, personnel classification, and choice of the dose monitoring method). It describes the various components of a risk management strategy (risk reduction, technical measures regarding the installation and the personnel, training and information, prevention and medical monitoring). It briefly presents how risk management is to be assessed, and mentions other related risks

  17. Evolution of Close Binary Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yakut, K; Eggleton, P

    2005-01-24

    We collected data on the masses, radii, etc. of three classes of close binary stars: low-temperature contact binaries (LTCBs), near-contact binaries (NCBs), and detached close binaries (DCBs). They restrict themselves to systems where (1) both components are, at least arguably, near the Main Sequence, (2) the periods are less than a day, and (3) there is both spectroscopic and photometric analysis leading to reasonably reliable data. They discuss the possible evolutionary connections between these three classes, emphasizing the roles played by mass loss and angular momentum loss in rapidly-rotating cool stars.

  18. Report IAU Comm. 42, Close Binary Stars

    OpenAIRE

    Ribas, Ignasi; Scarfe, Colin D.; Torres, Guillermo; Rucinski, Slavek M.; Sion, Edward M.; Richards, Mercedes T.; Niarchos, Panayiotis; Olah, Katalin

    2008-01-01

    Brief summaries are given about (1) close binary research from the perspective of the Bibliography of Close Binaries, (2) low-mass binaries and model discrepancies, (3) W UMa-type binaries, (4) cataclysmic variables, (5) Algol binaries, (6) the oEA stars, (7) effects of binarity on stellar activity.

  19. Production of an extensive sunflower protein hydrolysate by sequential hydrolysis with endo- and exo-proteases.

    Directory of Open Access Journals (Sweden)

    Villanueva, Alvaro

    1999-12-01

    Full Text Available A high quality protein isolate has been obtained from defatted sunflower meal by alkaline extraction and isoelectric precipitation. Protein content was increased from 31.2 % in the defatted flour to 97 % in the protein isolate. The percentages of fiber, soluble sugars, polyphenols and residual lipids in the protein isolate were reduced to more than 90 % with respect to the defatted meal. The protein isolate was used as starting material for the generation of an extensive enzymatic protein hydrolysate. The hydrolysis was carried out in a pH stat using sequentially an endo-protease (Alcalase and an exo-protease (Flavourzyme. The protein hydrolysate, with a degree of hydrolysis of 50.7 %, was white and non bitter.

    Se ha obtenido un aislado proteico de alta calidad a partir de harina desengrasada de girasol, mediante extracción alcalina y precipitación isoeléctrica. Se incrementó el contenido proteico desde un 31.2 % en la harina desengrasada hasta un 97 % en el aislado proteico. Los porcentajes de fibra, azúcares solubles, polifenoles y lípidos residuales se redujeron en más del 90 % en el aislado proteico respecto a la harina desengrasada. Se usó el aislado proteico como material de partida para la producción de un hidrolizado enzimático proteico extenso. La hidrólisis se realizó en un reactor usando secuencialmente una endo-proteasa (Alcalasa y una exo-proteasa (Flavorzima. El hidrolizado proteico, con un grado de hidrólisis del 50.7 %, era blanco y no presentaba amargor.

  20. Low autocorrelation binary sequences

    Science.gov (United States)

    Packebusch, Tom; Mertens, Stephan

    2016-04-01

    Binary sequences with minimal autocorrelations have applications in communication engineering, mathematics and computer science. In statistical physics they appear as groundstates of the Bernasconi model. Finding these sequences is a notoriously hard problem, that so far can be solved only by exhaustive search. We review recent algorithms and present a new algorithm that finds optimal sequences of length N in time O(N {1.73}N). We computed all optimal sequences for N≤slant 66 and all optimal skewsymmetric sequences for N≤slant 119.

  1. Magnetic binary nanofillers

    International Nuclear Information System (INIS)

    Magnetic binary nanofillers containing multiwall carbon nanotubes (MWCNT) and hercynite were synthesized by Chemical Vapor Deposition (CVD) on Fe/AlOOH prepared by the sol-gel method. The catalyst precursor was fired at 450 °C, ground and sifted through different meshes. Two powders were obtained with different particle sizes: sample A (50-75 μm) and sample B (smaller than 50 μm). These powders are composed of iron oxide particles widely dispersed in the non-crystalline matrix of aluminum oxide and they are not ferromagnetic. After reduction process the powders are composed of α-Fe nanoparticles inside hercynite matrix. These nanofillers are composed of hercynite containing α-Fe nanoparticles and MWCNT. The binary magnetic nanofillers were slightly ferromagnetic. The saturation magnetization of the nanofillers depended on the powder particle size. The nanofiller obtained from powder particles in the range 50-75 μm showed a saturation magnetization 36% higher than the one formed from powder particles smaller than 50 μm. The phenomenon is explained in terms of changes in the magnetic environment of the particles as consequence of the presence of MWCNT.

  2. Computing on Binary Strings

    CERN Document Server

    Bu, Tian-Ming; Zhang, Peng

    2011-01-01

    Many problems in Computer Science can be abstracted to the following question: given a set of objects and rules respectively, which new objects can be produced? In the paper, we consider a succinct version of the question: given a set of binary strings and several operations like conjunction and disjunction, which new binary strings can be generated? Although it is a fundamental problem, to the best of our knowledge, the problem hasn't been studied yet. In this paper, an O(m^2n) algorithm is presented to determine whether a string s is representable by a set W, where n is the number of strings in W and each string has the same length m. However, looking for the minimum subset from a set to represent a given string is shown to be NP-hard. In addition, we prove that counting the number of strings representable is #P-complete. But if the operator negation can be used, the number is some power of 2. This di?erence maybe help us understand the problem more profoundly.

  3. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Benacquista Matthew J.

    2006-02-01

    Full Text Available The galactic population of globular clusters are old, dense star systems, with a typical cluster containing 10^4 - 10^7 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss the theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution which lead to relativistic binaries, and current and possible future observational evidence for this population. Globular cluster evolution will focus on the properties that boost the production of hard binary systems and on the tidal interactions of the galaxy with the cluster, which tend to alter the structure of the globular cluster with time. The interaction of the components of hard binary systems alters the evolution of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker-Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  4. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Matthew J. Benacquista

    2013-03-01

    Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  5. PERIODIC COMPLEMENTARY BINARY SEQUENCE PAIRS

    Institute of Scientific and Technical Information of China (English)

    XuChengqian; ZhaoXiaoqun

    2002-01-01

    A new set of binary sequences-Periodic Complementary Binary Sequence Pair (PCSP)is proposed .A new class of block design-Difference Family Pair (DFP)is also proposed .The relationship between PCSP and DFP,the properties and exising conditions of PCSP and the recursive constructions for PCSP are given.

  6. PERIODIC COMPLEMENTARY BINARY SEQUENCE PAIRS

    Institute of Scientific and Technical Information of China (English)

    Xu Chengqian; Zhao Xiaoqun

    2002-01-01

    A new set of binary sequences-Periodic Complementary Binary Sequence Pair (PCSP) is proposed. A new class of block design-Difference Family Pair (DFP) is also proposed.The relationship between PCSP and DFP, the properties and existing conditions of PCSP and the recursive constructions for PCSP are given.

  7. Pairing mechanisms for binary stars

    CERN Document Server

    Kouwenhoven, M B N; Goodwin, S P; Zwart, S F Portegies; Kaper, L; 10.1002/asna.200811061

    2008-01-01

    Knowledge of the binary population in stellar groupings provides important information about the outcome of the star forming process in different environments. Binarity is also a key ingredient in stellar population studies and is a prerequisite to calibrate the binary evolution channels. In these proceedings we present an overview of several commonly used methods to pair individual stars into binary systems, which we refer to as the pairing function. Many pairing functions are frequently used by observers and computational astronomers, either for the mathematical convenience, or because they roughly describe the expected outcome of the star forming process. We discuss the consequences of each pairing function for the interpretation of observations and numerical simulations. The binary fraction and mass ratio distribution generally depend strongly on the selection of the range in primary spectral type in a sample. These quantities, when derived from a binary survey with a mass-limited sample of target stars, ...

  8. Planets in Binary Star Systems

    CERN Document Server

    Haghighipour, Nader

    2010-01-01

    The discovery of extrasolar planets over the past decade has had major impacts on our understanding of the formation and dynamical evolution of planetary systems. There are features and characteristics unseen in our solar system and unexplainable by the current theories of planet formation and dynamics. Among these new surprises is the discovery of planets in binary and multiple-star systems. The discovery of such "binary-planetary" systems has confronted astrodynamicists with many new challenges, and has led them to re-examine the theories of planet formation and dynamics. Among these challenges are: How are planets formed in binary star systems? What would be the notion of habitability in such systems? Under what conditions can binary star systems have habitable planets? How will volatiles necessary for life appear on such planets? This volume seeks to gather the current research in the area of planets in binary and multistar systems and to familiarize readers with its associated theoretical and observation...

  9. Towards Physarum Binary Adders

    CERN Document Server

    Jones, Jeff; 10.1016/j.biosystems.2010.04.005

    2010-01-01

    Plasmodium of \\emph{Physarum polycephalum} is a single cell visible by unaided eye. The plasmodium's foraging behaviour is interpreted in terms of computation. Input data is a configuration of nutrients, result of computation is a network of plasmodium's cytoplasmic tubes spanning sources of nutrients. Tsuda et al (2004) experimentally demonstrated that basic logical gates can be implemented in foraging behaviour of the plasmodium. We simplify the original designs of the gates and show --- in computer models --- that the plasmodium is capable for computation of two-input two-output gate $ \\to $ and three-input two-output $ \\to $. We assemble the gates in a binary one-bit adder and demonstrate validity of the design using computer simulation.

  10. Eccentric Binary Millisecond Pulsars

    CERN Document Server

    Freire, Paulo C C

    2009-01-01

    In this paper we review the recent discovery of several millisecond pulsars (MSPs) in eccentric binary systems. Timing these MSPs we were able to estimate (and in one case precisely measure) their masses. These results suggest that, as a class, MSPs have a much wider range of masses (1.3 to > 2 solar masses) than the normal and mildly recycled pulsars found in double neutron star (DNS) systems (1.25 < Mp < 1.44 solar masses). This is very likely to be due to the prolonged accretion episode that is thought to be required to form a MSP. The likely existence of massive MSPs makes them a powerful probe for understanding the behavior of matter at densities larger than that of the atomic nucleus; in particular, the precise measurement of the mass of PSR J1903+0327 ($1.67 +/- 0.01 solar masses) excludes several "soft" equations of state for dense matter.

  11. Binaries and distances

    Science.gov (United States)

    Pourbaix, D.; Arenou, F.; Halbwachs, J.-L.; Siopis, C.

    2013-02-01

    Gaia's five-year observation baseline might naively lead to the expectation that it will be possible to fit the parallax of any sufficiently nearby object with the default five-parameter model (position at a reference epoch, parallax and proper motion). However, simulated Gaia observations of a `model Universe' composed of nearly 107 objects, 50% of which turn out to be multiple stars, show that the single-star hypothesis can severely affect parallax estimation and that more sophisticated models must be adopted. In principle, screening these spurious single-star solutions is rather straightforward, for example by evaluating the quality of the fits. However, the simulated Gaia observations also reveal that some seemingly acceptable single-star solutions can nonetheless lead to erroneous distances. These solutions turn out to be binaries with an orbital period close to one year. Without auxiliary (e.g., spectroscopic) data, they will remain unnoticed.

  12. NASA ExoPAG Study Analysis Group 5: Flagship Exoplanet Imaging Mission Science Goals and Requirements Report

    CERN Document Server

    Greene, Tom

    2013-01-01

    The NASA Exoplanet Program Analysis Group (ExoPAG) has undertaken an effort to define mission Level 1 requirements for exoplanet direct detection missions at a range of sizes. This report outlines the science goals and requirements for the next exoplanet flagship imaging and spectroscopy mission as determined by the flagship mission Study Analysis Group (SAG) of the NASA Exoplanet Program Analysis Group (ExoPAG). We expect that these goals and requirements will be used to evaluate specific architectures for a future flagship exoplanet imaging and spectroscopy mission, and we expect this effort to serve as a guide and template for similar goals and requirements for smaller missions, an effort that we expect will begin soon. These goals and requirements were discussed, determined, and documented over a 1 year period with contributions from approximately 60 volunteer exoplanet scientists, technologists, and engineers. Numerous teleconferences, emails, and several in-person meetings were conducted to progress on ...

  13. 结球甘蓝ARC1与Exo70A1编码区cDNA的克隆及进化分析%Cloning and Phylogenetic Analysis of cDNA Sequences Coding for ARC1 and Exo70A1 in Brassica oleracesvar.capitata L.

    Institute of Scientific and Technical Information of China (English)

    杨丹; 廉小平; 周燕; 张贺翠; 杜丹; 高启国; 任雪松; 朱利泉

    2016-01-01

    Interaction between ARC1 and Exo70A1 in Brassica is a key point of self-incompatibility(SI)signal transduction. In order to study the evolutionary relationship of ARC1 and Exo70A1 from 10 cultivars of SI head cabbages developed in recent years,we successfully cloned and sequenced cDNAs of ARC1 and Exo70A1. Furthermore,by bioinformatics,we had mutation and evolutionary analysis of those coding region sequences,including interaction region and non-interaction regions of ARC1-Exo70A1 from the 10 cabbages and prior published 83 ARC1 and 73 Exo70A1 sequences. The results revealed that:1)The coding nucleic acid sequences of ARC1 and Exo70A1 from the 10 cabbage materials presented parallel evolutionary relationships,and belonged to the Brassica branch. 2)The evolution rate of coding sequence of ARC1 was faster than Exo70A1. 3)The interaction coding region of ARC1-Exo70A1 was obviously in the progress of co-evolution,while the non-interaction coding area of ARC1-Exo70A1 showed significant differentiation rate in evolution. 4)The evolutionary rate of interaction coding area was faster than non-interaction coding region.%在甘蓝自交不亲和信号传导过程中,ARC1与Exo70A1的相互作用起着承上启下的关键作用。为了研究10种自交不亲和结球甘蓝材料ARC1和Exo70A1的进化关系,对其编码区cDNA进行了克隆和测序;在此基础上采用生物信息学方法,对这10种材料和前人已发表的83条ARC1和73条Exo70A1的相关序列的ARC1-Exo70A1的互作区和非互作区编码序列进行了变异和进化分析。结果发现:(1)所选育的10种结球甘蓝材料的ARC1与Exo70A1的编码区核酸序列存在平行进化关系,且均聚类于芸薹属分支下;(2)ARC1比Exo70A1编码区序列进化速率快;(3)ARC1和Exo70A1互作编码区核酸序列存在明显的协同进化,而ARC1和Exo70A1非互作编码区核酸序列则在进化上呈现明显分异;(4)ARC1和Exo70A1互作编码区cDNA的

  14. Hypoglycemic Effects of Exo-biopolymers Produced by Five Different Medicinal Mushrooms in STZ-induced Diabetic Rats

    OpenAIRE

    Yang, Byung-Keun; Kim, Guk-Nam; Jeong, Yong-Tae; Jeong, Hun; Mehta, Pradeep; Song, Chi-Hyun

    2008-01-01

    Hypoglycemic effects of exo-biopolymers (EBP) produced by submerged mycelial cultures of Coriolus versicolor, Cordyceps sinensis, Paecilomyces japonica, Armillariella mellea, and Fomes fomentarius were investigated in streptozotocin (STZ)-induced diabetic rats. The rats from each experimental group were orally administered with EBPs (100 mg/kg BW) daily for 2 weeks. Though the hypoglycemic effect was achieved in all the cases, however, C. versicolor EBP proved as the most potent one. The admi...

  15. Optimized extraction, composition, antioxidant and antimicrobial activities of exo and intracellular polysaccharides from submerged culture of Cordyceps cicadae

    OpenAIRE

    SHARMA, SAPAN KUMAR; GAUTAM, NANDINI; Atri, Narender Singh

    2015-01-01

    Background Cordyceps cicadae is known as Jin Chan Hua in Traditional Chinese Medicine and known to possess different pharmacological activities. Presently, it was collected from the wild and isolated. Mycelial culture was optimized for extraction of polysaccharides under submerged culture conditions. Besides antioxidant, antibacterial activities of extracted polysaccharides were tested for first time. Methods Exo-polysaccharides (EPS) and intracellular polysaccharides (IPS) production was tes...

  16. Fission yeast Sec3 and Exo70 are transported on actin cables and localize the exocyst complex to cell poles.

    Directory of Open Access Journals (Sweden)

    Felipe O Bendezú

    Full Text Available The exocyst complex is essential for many exocytic events, by tethering vesicles at the plasma membrane for fusion. In fission yeast, polarized exocytosis for growth relies on the combined action of the exocyst at cell poles and myosin-driven transport along actin cables. We report here the identification of fission yeast Schizosaccharomyces pombe Sec3 protein, which we identified through sequence homology of its PH-like domain. Like other exocyst subunits, sec3 is required for secretion and cell division. Cells deleted for sec3 are only conditionally lethal and can proliferate when osmotically stabilized. Sec3 is redundant with Exo70 for viability and for the localization of other exocyst subunits, suggesting these components act as exocyst tethers at the plasma membrane. Consistently, Sec3 localizes to zones of growth independently of other exocyst subunits but depends on PIP(2 and functional Cdc42. FRAP analysis shows that Sec3, like all other exocyst subunits, localizes to cell poles largely independently of the actin cytoskeleton. However, we show that Sec3, Exo70 and Sec5 are transported by the myosin V Myo52 along actin cables. These data suggest that the exocyst holocomplex, including Sec3 and Exo70, is present on exocytic vesicles, which can reach cell poles by either myosin-driven transport or random walk.

  17. Utilization of wheat bran for enhanced production of exo-polygalacturonase by penicillium notatum using response surface methodology

    International Nuclear Information System (INIS)

    Response surface methodology (RSM) has been one of the most commonly used optimization method in the recent years. Especially this technique is frequently used in the enzyme biotechnology. In this context Penicillium notatum was evaluated for enhanced biosynthesis of exo-polygalacturonse using statistical approach under solid state fermentation (SSF). Nine parameters were assessed for maximum biosynthesis of the enzyme using classical method (data not shown). Four factors (3 numerical and 1 categorical factor) were evaluated as the best having the influential effect on enzyme yield. These factors were incubation time (days), temperature (degree C), pH, and nitrogen sources. Nitrogen sources like glycine and ammonium chloride, were selected in RSM optimization as they were found to be the most promising in multiplying the exo-polygalacturonse activity during the classical approach. Maximum activity of the enzyme achieved was 1129.62 U/gds with incubation period 3 days, pH 1.318, temperature 30 degree C and using ammonium chloride as nitrogen source. All the experiments were performed at 40 % (V/W) moisture level using 10 g of wheat bran as substrate. An increase of 5.5 folds of activity was observed using this technique as compared to classical method. The results indicated that RSM could be used to get enhanced activities of exo-polygalacturonse under SSF. (author)

  18. Control of Grifola frondosa Morphology by Agitation and Aeration for Improving Mycelia and Exo-Polymer Production.

    Science.gov (United States)

    Cui, Feng-Jie; Chen, Xiao-Xiao; Liu, Wei-Min; Sun, Wen-Jing; Huo, Shuhao; Yang, Yan

    2016-06-01

    The present study describes the improved mycelia and exo-polymer production under control of Grifola frondosa morphology by changing the aeration rate and agitation intensity in a 25-L stirred fermentor. The aeration rate of 1.0 vvm yielded a highest mycelia biomass of 24.754 g/L with the lowest pellet percentage of 20.5 %. The maximum exo-polymer (2.324 g/L) was achieved at 0.75 vvm with mycelia polysaccharide production (0.321 g/g), whereas clumps and filaments dominated the ratios of 45.6 and 33.9 %, respectively. The change of aeration rate and agitation intensity had slight influence on the monosaccharide compositions in exo-polymers and significantly affected glucose and mannose contents in the mycelia polysaccharides. These findings will provide a clue for exploring the relationship between fermentation parameters, morphologies, and polysaccharide synthesis pathway of G. frondosa. PMID:26861733

  19. Crystallization and preliminary X-ray crystallographic studies of an exo-β-d-glucosaminidase from Trichoderma reesei

    International Nuclear Information System (INIS)

    An exo-β-d-glucosaminidase from T. reesei (Gls93) has been crystallized by the hanging-drop vapour-diffusion method. Diffraction data have been collected using synchrotron radiation. Chitosan is degraded to glucosamine (GlcN) by chitosanase and exo-β-d-glucosaminidase (GlcNase). GlcNase from Trichoderma reesei (Gls93) is a 93 kDa extracellular protein composed of 892 amino acids. The enzyme liberates GlcN from the nonreducing end of the chitosan chain in an exo-type manner and belongs to glycoside hydrolase family 2. For crystallographic investigations, Gls93 was overexpressed in Pichia pastoris cells. The recombinant Gls93 had two molecular forms of ∼105 kDa (Gls93-F1) and ∼100 kDa (Gls93-F2), with the difference between them being caused by N-glycosylation. Both forms were crystallized by the hanging-drop vapour-diffusion method. Crystals of Gls93-F1 belonged to the orthorhombic space group P212121, with unit-cell parameters a = 98.27, b = 98.42, c = 108.28 Å, and diffracted to 1.8 Å resolution. Crystals of Gls93-F2 belonged to the orthorhombic space group P212121, with unit-cell parameters a = 67.84, b = 81.62, c = 183.14 Å, and diffracted to 2.4 Å resolution. Both crystal forms were suitable for X-ray structure analysis at high resolution

  20. Combined action of the major secreted exo- and endopolygalacturonases is required for full virulence of Fusarium oxysporum.

    Science.gov (United States)

    Bravo Ruiz, Gustavo; Di Pietro, Antonio; Roncero, M Isabel G

    2016-04-01

    The genome of the tomato pathogen Fusarium oxysporum f. sp. lycopersici encodes eight different polygalacturonases (PGs): four endoPGs and four exoPGs. Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed that endoPGs pg1 and pg5 and exoPGs pgx4 and pgx6 are expressed at significant levels during growth on citrus pectin, polygalacturonic acid or the monomer galacturonic acid, as well as during the infection of tomato plants. The remaining PG genes exhibit low expression levels under all the conditions tested. Secreted PG activity was decreased significantly during growth on pectin in the single deletion mutants lacking either pg1 or pgx6, as well as in the double mutant. Although the single deletion mutants did not display a significant virulence reduction on tomato plants, the Δpg1Δpgx6 double mutant was significantly attenuated in virulence. The combined action of exoPGs and endoPGs is thus essential for plant infection by the vascular wilt fungus F. oxysporum. PMID:26060046

  1. NOMAD on the ExoMars TGO 2016 mission: MAIT and characterisation testing

    Science.gov (United States)

    Vandaele, Ann C.; Neefs, Eddy; Lopez-Moreno, J. J.; Rodriguez Gomez, Julio; Drummond, Rachel; Patel, Manish; Thomas, Ian; Gissot, Samuel; Depiesse, Cedric; Ben Moussa, Ali; Giordanengo, Boris; Bellucci, Giancarlo

    NOMAD, the “Nadir and Occultation for MArs Discovery” spectrometer suite has been selected by ESA and NASA to be part of the payload of the ExoMars Trace Gas Orbiter mission 2016. This instrument suite will conduct a spectroscopic survey of Mars’ atmosphere in the UV, visible and IR regions covering the 0.2-0.65 and 2.2-4.3 μm spectral ranges. NOMAD’s observation modes include solar occultation, nadir and limb observations. The NOMAD instrument is composed of 3 channels: a solar occultation only channel (SO) operating in the infrared wavelength domain, a second infrared channel capable of observing nadir, solar occultation and limb observations (LNO), and an ultraviolet/visible channel (UVIS) that can work in all observation modes. The spectral resolution of SO and LNO surpasses previous surveys in the infrared by more than one order of magnitude. NOMAD offers an integrated instrument combination of a flight-proven concept (SO is a copy of SOIR on Venus Express), and innovations based on existing and proven instrumentation (LNO is based on SOIR/VEX and UVIS has heritage from the ExoMars lander), that will provide mapping and vertical profile information at high spatio-temporal resolution. The three channels have each their own ILS and optical bench, but share the same single interface to the S/C. The NOMAD flight model is due for delivery to ESA in January 2015. We will present results so far of the manufacturing, assembly and especially testing of the various components. The UV CCDs have been characterised in thermal-vacuum; optical fibres have been studied with UV exposure to look at transmission degradation; the IR AOTFs have been tested for their transfer functions; lifetime and vibration testing has been carried out on the flip mirror mechanism. These are all vital inputs to the scientific results from NOMAD. Acknowledgements - The research program was supported by the Belgian Federal Science Policy Office and the European Space Agency (ESA PRODEX

  2. Binary black hole spectroscopy

    International Nuclear Information System (INIS)

    We study parameter estimation with post-Newtonian (PN) gravitational waveforms for the quasi-circular, adiabatic inspiral of spinning binary compact objects. In particular, the performance of amplitude-corrected waveforms is compared with that of the more commonly used restricted waveforms, in Advanced LIGO and EGO. With restricted waveforms, the properties of the source can only be extracted from the phasing. In the case of amplitude-corrected waveforms, the spectrum encodes a wealth of additional information, which leads to dramatic improvements in parameter estimation. At distances of ∼100 Mpc, the full PN waveforms allow for high-accuracy parameter extraction for total mass up to several hundred solar masses, while with the restricted ones the errors are steep functions of mass, and accurate parameter estimation is only possible for relatively light stellar mass binaries. At the low-mass end, the inclusion of amplitude corrections reduces the error on the time of coalescence by an order of magnitude in Advanced LIGO and a factor of 5 in EGO compared to the restricted waveforms; at higher masses these differences are much larger. The individual component masses, which are very poorly determined with restricted waveforms, become measurable with high accuracy if amplitude-corrected waveforms are used, with errors as low as a few per cent in Advanced LIGO and a few tenths of a per cent in EGO. The usual spin-orbit parameter β is also poorly determined with restricted waveforms (except for low-mass systems in EGO), but the full waveforms give errors that are small compared to the largest possible value consistent with the Kerr bound. This suggests a way of finding out if one or both of the component objects violate this bound. On the other hand, we find that the spin-spin parameter σ remains poorly determined even when the full waveform is used. Generally, all errors have but a weak dependence on the magnitudes and orientations of the spins. We also briefly

  3. The NOMAD Spectrometer Suite on ExoMars Trace Gas Orbiter

    Science.gov (United States)

    Carine Vandaele, Ann; Lopez-Moreno, Jose-Juan; Patel, Manish R.; Bellucci, Giancarlo; Neefs, Eddy; Thomas, Ian R.; Drummond, Rachel; Rodriguez-Gomez, Julio; Daerden, Frank

    2016-04-01

    NOMAD (Nadir and Occultation for MArs Discovery) is a suite of three high-resolution spectrometers on-board the ExoMars Trace Gas Orbiter. The instrument will be able to detect and map a wide variety of Martian gases in unprecedented detail. NOMAD's three spectrometers cover the UV-visible (UVIS channel - 200-650nm) and infrared ranges (SO and LNO channels - 2.2-4.3μm), operating in solar occultation, limb and nadir-viewing modes, generating a huge dataset of Martian atmospheric observations during the mission across a wide spectral range. NOMAD has the resolving power to identify many trace gases that exhibit absorption features within the spectral range of the three channels. The order-of-magnitude increase in spectral resolution over previous instruments will enable spatial and temporal mapping of several isotopologues of methane and water, providing important measurements of the Martian D/H and methane isotope ratios globally. Sensitivity studies have shown that, using expected SNR values, NOMAD should have the ability to measure methane concentrations averaged sufficiently. Using SO and LNO in combination with UVIS, aerosol properties such as optical depth, composition and size distribution can also be derived. NOMAD will also continue to monitor the major seasonal cycles on Mars, extending existing datasets made by successive space missions in the past decade.

  4. An extreme EXO: a type 2 QSO at z=1.87

    CERN Document Server

    Del Moro, A; Mateos, S; Akiyama, M; Hashimoto, Y; Tamura, N; Ohta, K; Carrera, F J; Stewart, G

    2008-01-01

    We aim to understand the multi-wavelength properties of 2XMM J123204+215255, the source with the most extreme X-ray-to-optical flux ratio amongst a sample of bright X-ray selected EXOs drawn from a cross-correlation of the 2XMMp catalogue with the SDSS-DR5 catalogue. We use 2XMMp X-ray data, SDSS-DR5, NOT and UKIRT optical/NIR photometric data and Subaru MOIRCS IR spectroscopy to study the properties of 2XMM J123204+215255. We created a model SED including an obscured QSO and the host galaxy component to constrain the optical/IR extinction and the relative contribution of the AGN and the galaxy to the total emission. 2XMM J123204+215255 is a bright X-ray source with f_X~10^{-12} erg cm^{-2} s^{-1} (2-10 keV energy band) which has no detection down to a magnitude i' > 25.2. NIR imaging reveals a faint K-band counterpart and NIR spectroscopy shows a single broad (FWHM=5300 km/s) emission line, which is almost certainly H-alpha at z=1.87. The X-ray spectrum shows evidence of significant absorption (N_H > 10^{23}...

  5. Crushable Structure for the Landing Impact of a European Mars Exploration Mission (ExoMars 2016)

    Science.gov (United States)

    del Campo, F.; Bernar, E.; Biondetti, G.; Jauregui, Y. E.; Walloschek, T.

    2012-07-01

    The first mission of the ExoMars programme, scheduled to arrive at Mars in 2016, includes an Entry, Descent and Landing Demonstrator Module (EDM). One of the EDM objectives is to demonstrate the possibility to safely absorb the landing impact by means of a deformable structure placed under the Surface Platform (SP), the EDM sub-module reaching ground. This is one of the key technologies in preparation for ESA's contribution to subsequent missions to Mars. SENER is responsible for several structures and mechanisms for the EDM, with TAS-I as Prime contractor. The paper focuses on the Crushable Structure, which is the main element affected by the impact. Its function is to absorb the landing impact after thruster switch off at around 2 meters over the Martian surface, allowing a safe landing for the equipments in terms of acceleration levels, and for the whole structure in terms of stability and non-overturning. An optimized structure has been designed for this purpose, within a restricted envelope, able to meet these requirements for a wide range of terrain configurations, including rocks and slopes.

  6. Studies on Exo-Chitinase Production from Trichoderma asperellum UTP-16 and Its Characterization.

    Science.gov (United States)

    Kumar, D Praveen; Singh, Rajesh Kumar; Anupama, P D; Solanki, Manoj Kumar; Kumar, Sudheer; Srivastava, Alok K; Singhal, Pradeep K; Arora, Dilip K

    2012-09-01

    The growth conditions for chitinase production by Trichoderma asperellum UTP-16 in solid state fermentation was optimized using response surface methodology based on central composite design. The chitinase production was optimized, using one-factor at a time approach, with six independent variables (temperature, pH, NaCl, incubation period, nitrogen and carbon sources) and 3.31 Units per gram dry substrate (U gds(-1)) exo-chitinase yield was obtained. A 21.15% increase was recorded in chitinase activity (4.01 U gds(-1)) through surface response methodology, indicates that it is a powerful and rapid tool for optimization of physical and nutritional variables. Further, efficiency of crude enzyme was evaluated against phytopathogenic Fusarium spp. and a mycelial growth inhibition up to 3.5-6.5 mm was achieved in well diffusion assay. These results could be supplemented as basic information for the development of enzyme based formulation of T. asperellum UTP-16 and its use as a biocontrol agent. PMID:23997329

  7. The Detectability of Exo-Earths and Super-Earths Via Resonant Signatures in Exozodiacal Clouds

    CERN Document Server

    Stark, Christopher C

    2008-01-01

    Directly imaging extrasolar terrestrial planets necessarily means contending with the astrophysical noise of exozodiacal dust and the resonant structures created by these planets in exozodiacal clouds. Using a custom tailored hybrid symplectic integrator we have constructed 120 models of resonant structures created by exo-Earths and super-Earths on circular orbits interacting with collisionless steady-state dust clouds around a Sun-like star. Our models include enough particles to overcome the limitations of previous simulations that were often dominated by a handful of long-lived particles, allowing us to quantitatively study the contrast of the resulting ring structures. We found that in the case of a planet on a circular orbit, for a given star and dust source distribution, the morphology and contrast of the resonant structures depend on only two parameters: planet mass and $\\sqrt{a_{\\rm p}}/\\beta$, where $a_{\\rm p}$ is the planet's semi-major axis and $\\beta$ is the ratio of radiation pressure force to gr...

  8. Cytosolic organelles shape calcium signals and exo-endocytotic responses of chromaffin cells.

    Science.gov (United States)

    García, Antonio G; Padín, Fernando; Fernández-Morales, José C; Maroto, Marcos; García-Sancho, Javier

    2012-01-01

    The concept of stimulus-secretion coupling was born from experiments performed in chromaffin cells 50 years ago. Stimulation of these cells with acetylcholine enhances calcium (Ca(2+)) entry and this generates a transient elevation of the cytosolic Ca(2+) concentration ([Ca(2+)](c)) that triggers the exocytotic release of catecholamines. The control of the [Ca(2+)](c) signal is complex and depends on various classes of plasmalemmal calcium channels, cytosolic calcium buffers, the uptake and release of Ca(2+) from cytoplasmic organelles, such as the endoplasmic reticulum, mitochondria, chromaffin vesicles and the nucleus, and Ca(2+) extrusion mechanisms, such as the plasma membrane Ca(2+)-stimulated ATPase, and the Na(+)/Ca(2+) exchanger. Computation of the rates of Ca(2+) fluxes between the different cell compartments support the proposal that the chromaffin cell has developed functional calcium tetrads formed by calcium channels, cytosolic calcium buffers, the endoplasmic reticulum, and mitochondria nearby the exocytotic plasmalemmal sites. These tetrads shape the Ca(2+) transients occurring during cell activation to regulate early and late steps of exocytosis, and the ensuing endocytotic responses. The different patterns of catecholamine secretion in response to stress may thus depend on such local [Ca(2+)](c) transients occurring at different cell compartments, and generated by redistribution and release of Ca(2+) by cytoplasmic organelles. In this manner, the calcium tetrads serve to couple the variable energy demands due to exo-endocytotic activities with energy production and protein synthesis. PMID:22209033

  9. Monte Carlo Simulation of the EXO Gaseous Xenon Time Projection Chamber and Neural Network Analysis

    Science.gov (United States)

    Leonard, Francois

    Neutrinoless double beta decay has attracted much interest since its observation would reveal the neutrino masses and determine the Majorana nature of the particle. EXO is among the next generation of experiments dedicated to the search for this phenomenon. A part of the collaboration is developing a gas phase time projection chamber prototype to study the performance of this technique for measuring the half-life of neutrinoless double beta decay in 136Xe. A Monte Carlo simulation of this prototype has been developed using the Geant4 toolkit and the Garfield and Maxwell programs to simulate ionizing events in the detector, the production and propagation of the scintillation and electroluminescence signals and their distribution on CsI photocathodes. The simulation was used to study the uniformity of light deposition on the photocathodes, the effect of the natural gamma background radiation on the detector and its response to calibration gamma sources. Furthermore, data produced with this simulation were analyzed with a neural network algorithm using the multi-layer perceptron class implemented in ROOT. The performance of this algorithm was studied for vertex reconstruction of ionizing events in the detector as well as for classification of tracks for background rejection.

  10. Exo-Planetary Phoenix: Rebirth of Planetary Systems Beyond the Main Sequence

    Science.gov (United States)

    Marengo, M.

    2014-04-01

    Mounting evidence suggests that planetary systems may be a common feature of stars that have evolved beyond the main sequence. Warm debris disks around white dwarfs and "pulsar" planets orbiting a neutron star are a strong indication that planetary systems may, at least in same cases, survive the dramatic phenomena leading to stellar death. A close look at these late evolutionary stages, however, suggests that these systems may be more than mere survivors of doomed pre-existing exo-planetary systems. The circumstellar environment of post-main sequence stars bears surprising similarities to the conditions leading to pre-main sequence planetary formation: a metal-rich environment often characterized by the presence of circumstellar or circumbinary disks. Are these conditions conducive to the birth of a second-generation planetary system, like a phoenix rising from the ashes of ancient worlds? In this talk we will discuss how the physical conditions in the winds of dusty giant stars may be favorable for renewed planetary formation, with particular emphasis on the effects of enhanced metallicity, binarity and the timescales available for the formation of a new generation of planets.

  11. Measurements of Water Absorption in the Warm Exo-Uranus GJ 3470b

    Science.gov (United States)

    Benneke, Björn; Crossfield, Ian; Knutson, Heather; McCullough, Peter; Lothringer, Joshua; Howard, Andrew; Morley, Caroline; Fortney, Jonathan; Dragomir, Diana; Gilliland, Ron

    2015-12-01

    The discovery of short-period planets with masses and radii intermediate between Earth and Neptune was one of the biggest surprises in the brief history of exoplanet science. These “super-Earths” and “sub-Neptunes” are an order of magnitude more abundant than close-in giant planets. Despite this ubiquity, we know little about their typical compositions and formation histories. Spectroscopic transit observations can shed new light on these mysterious worlds by probing their atmospheric compositions. In this talk, we will give an overview of our ongoing 124-orbit (200-hour) Hubble Space Telescope program to reveal the chemical diversity and formation histories of super-Earths. This unprecedented survey will provide the first comprehensive look at this intriguing new class of planets ranging from 1 Neptune mass and temperatures close to 2000K to a 1 Earth mass planet near the habitable zone of its host star. In this talk, I will discuss the scope of the program and present early science results including measurements of water absorption in the atmosphere of the warm exo-Uranus GJ3470b.

  12. The ExoMol project: Software for computing large molecular line lists

    CERN Document Server

    Tennyson, Jonathan

    2016-01-01

    The use of variational nuclear motion programs to compute line lists of transition frequencies and intensities is now a standard procedure. The ExoMol project has used this technique to generate line lists for studies of hot bodies such as the atmospheres of exoplanets and cool stars. The resulting line list can be huge: many contain 10 billion or more transitions. This software update considers changes made to our programs during the course of the project to allow for such calculations. This update considers three programs: {\\sc Duo} which computed vibronic spectra for diatomics, {\\sc DVR3D} which computes rotation-vibration spectra for triatomics, and {\\sc TROVE} which computes rotation-vibration spectra for general polyatomic systems. Important updates in functionality include the calculation of quasibound (resonance) states and Land\\'e $g$-factors by {\\sc Duo} and the calculation of resonance states by {\\sc DVR3D}. Significant algorithmic improvements are reported for both {\\sc DVR3D} and {\\sc TROVE}. All...

  13. Flight Mechanics of the Entry, Descent and Landing of the ExoMars Mission

    Science.gov (United States)

    HayaRamos, Rodrigo; Boneti, Davide

    2007-01-01

    ExoMars is ESA's current mission to planet Mars. A high mobility rover and a fixed station will be deployed on the surface of Mars. This paper regards the flight mechanics of the Entry, Descent and Landing (EDL) phases used for the mission analysis and design of the Baseline and back-up scenarios of the mission. The EDL concept is based on a ballistic entry, followed by a descent under parachutes and inflatable devices (airbags) for landing. The mission analysis and design is driven by the flexibility in terms of landing site, arrival dates and the very stringent requirement in terms of landing accuracy. The challenging requirements currently imposed to the mission need innovative analysis and design techniques to support system design trade-offs to cope with the variability in entry conditions. The concept of the Global Entry Corridor has been conceived, designed, implemented and successfully validated as a key tool to provide a global picture of the mission capabilities in terms of landing site reachability.

  14. Strong Lensing by Binary Galaxies

    CERN Document Server

    Shin, E M

    2008-01-01

    We study the problem of gravitational lensing by binary galaxies, idealized as two isothermal spheres. In a wide binary, each galaxy possesses individual tangential, nearly astroidal, caustics and roundish radial caustics. As the separation of the binary is made smaller, the caustics undergo a sequence of metamorphoses. The first metamorphosis occurs when the tangential caustics merge to form a single six-cusped caustic, lying interior to the radial caustics. At still smaller separations, the six-cusped caustic undergoes the second metamorphosis and splits into a four-cusped caustic and two three-cusped caustics, which shrink to zero size (an elliptic umbilic catastrophe) before they enlarge again and move away from the origin perpendicular to the binary axis. Finally, a third metamorphosis occurs as the three-cusp caustics join the radial caustics, leaving an inner distorted astroid caustic enclosed by two outer caustics. The maximum number of images possible is 7. Classifying the multiple imaging according ...

  15. Magnetic braking in ultracompact binaries

    CERN Document Server

    Farmer, Alison

    2010-01-01

    Angular momentum loss in ultracompact binaries, such as the AM Canum Venaticorum stars, is usually assumed to be due entirely to gravitational radiation. Motivated by the outflows observed in ultracompact binaries, we investigate whether magnetically coupled winds could in fact lead to substantial additional angular momentum losses. We remark that the scaling relations often invoked for the relative importance of gravitational and magnetic braking do not apply, and instead use simple non-empirical expressions for the braking rates. In order to remove significant angular momentum, the wind must be tied to field lines anchored in one of the binary's component stars; uncertainties remain as to the driving mechanism for such a wind. In the case of white dwarf accretors, we find that magnetic braking can potentially remove angular momentum on comparable or even shorter timescales than gravitational waves over a large range in orbital period. We present such a solution for the 17-minute binary AM CVn itself which a...

  16. Discs in misaligned binary systems

    CERN Document Server

    Rawiraswattana, Krisada; Goodwin, Simon P

    2016-01-01

    We perform SPH simulations to study precession and changes in alignment between the circumprimary disc and the binary orbit in misaligned binary systems. We find that the precession process can be described by the rigid-disc approximation, where the disc is considered as a rigid body interacting with the binary companion only gravitationally. Precession also causes change in alignment between the rotational axis of the disc and the spin axis of the primary star. This type of alignment is of great important for explaining the origin of spin-orbit misaligned planetary systems. However, we find that the rigid-disc approximation fails to describe changes in alignment between the disc and the binary orbit. This is because the alignment process is a consequence of interactions that involve the fluidity of the disc, such as the tidal interaction and the encounter interaction. Furthermore, simulation results show that there are not only alignment processes, which bring the components towards alignment, but also anti-...

  17. Cryptography with DNA binary strands.

    Science.gov (United States)

    Leier, A; Richter, C; Banzhaf, W; Rauhe, H

    2000-06-01

    Biotechnological methods can be used for cryptography. Here two different cryptographic approaches based on DNA binary strands are shown. The first approach shows how DNA binary strands can be used for steganography, a technique of encryption by information hiding, to provide rapid encryption and decryption. It is shown that DNA steganography based on DNA binary strands is secure under the assumption that an interceptor has the same technological capabilities as sender and receiver of encrypted messages. The second approach shown here is based on steganography and a method of graphical subtraction of binary gel-images. It can be used to constitute a molecular checksum and can be combined with the first approach to support encryption. DNA cryptography might become of practical relevance in the context of labelling organic and inorganic materials with DNA 'barcodes'. PMID:10963862

  18. AN IMPROVED DESIGN OF REVERSIBLE BINARY TO BINARY CODED DECIMAL CONVERTER FOR BINARY CODED DECIMAL MULTIPLICATION

    Directory of Open Access Journals (Sweden)

    Praveena Murugesan

    2014-01-01

    Full Text Available Reversible logic gates under ideal conditions produce zero power dissipation. This factor highlights the usage of these gates in optical computing, low power CMOS design, quantum optics and quantum computing. The growth of decimal arithmetic in various applications as stressed the need to propose the study on reversible binary to BCD converter which plays a greater role in decimal multiplication for providing faster results. The different parameters such as gate count,garbage output and constant input are more optimized in the proposed fixed bit binary to binary coded decimal converter than the existing design.

  19. Transient Black Hole Binaries

    CERN Document Server

    Belloni, T M

    2016-01-01

    The last two decades have seen a great improvement in our understand- ing of the complex phenomenology observed in transient black-hole binary systems, especially thanks to the activity of the Rossi X-Ray Timing Explorer satellite, com- plemented by observations from many other X-ray observatories and ground-based radio, optical and infrared facilities. Accretion alone cannot describe accurately the intricate behavior associated with black-hole transients and it is now clear that the role played by different kinds of (often massive) outflows seen at different phases of the outburst evolution of these systems is as fundamental as the one played by the accretion process itself. The spectral-timing states originally identified in the X-rays and fundamentally based on the observed effect of accretion, have acquired new importance as they now allow to describe within a coherent picture the phenomenology observed at other wave- length, where the effects of ejection processes are most evident. With a particular focu...

  20. Binary nucleation beyond capillarity approximation

    OpenAIRE

    Kalikmanov, V.I.

    2010-01-01

    Large discrepancies between binary classical nucleation theory (BCNT) and experiments result from adsorption effects and inability of BCNT, based on the phenomenological capillarity approximation, to treat small clusters. We propose a model aimed at eliminating both of these deficiencies. Adsorption is taken into account within Gibbsian approximation. Binary clusters are treated by means of statistical-mechanical considerations: tracing out the molecular degrees of freedom of the more volatil...

  1. Clostridium difficile binary toxin CDT

    OpenAIRE

    Gerding, Dale N.; Johnson, Stuart; Rupnik, Maja; Aktories, Klaus

    2013-01-01

    Binary toxin (CDT) is frequently observed in Clostridium difficile strains associated with increased severity of C. difficile infection (CDI). CDT belongs to the family of binary ADP-ribosylating toxins consisting of two separate toxin components: CDTa, the enzymatic ADP-ribosyltransferase which modifies actin, and CDTb which binds to host cells and translocates CDTa into the cytosol. CDTb is activated by serine proteases and binds to lipolysis stimulated lipoprotein receptor. ADP-ribosylatio...

  2. Coalescence of Binary Neutron Stars

    OpenAIRE

    Oohara, Ken-ichi; Namamura, Takashi

    1996-01-01

    The most important sources for laser-interferometric gravitational-wave detectors like LIGO or VIRGO are catastrophic events such as coalescence of a neutron-star binary. The final phase, or the last three milliseconds, of coalescence is considered. We describe results of numerical simulations of coalescing binary neutron stars using Newtonian and post-Newtonian hydrodynamics code and then discuss recent development of our 3D GR code.

  3. Binary Encodings of Non-binary Constraint Satisfaction Problems: Algorithms and Experimental Results

    CERN Document Server

    Samaras, N; 10.1613/jair.1776

    2011-01-01

    A non-binary Constraint Satisfaction Problem (CSP) can be solved directly using extended versions of binary techniques. Alternatively, the non-binary problem can be translated into an equivalent binary one. In this case, it is generally accepted that the translated problem can be solved by applying well-established techniques for binary CSPs. In this paper we evaluate the applicability of the latter approach. We demonstrate that the use of standard techniques for binary CSPs in the encodings of non-binary problems is problematic and results in models that are very rarely competitive with the non-binary representation. To overcome this, we propose specialized arc consistency and search algorithms for binary encodings, and we evaluate them theoretically and empirically. We consider three binary representations; the hidden variable encoding, the dual encoding, and the double encoding. Theoretical and empirical results show that, for certain classes of non-binary constraints, binary encodings are a competitive op...

  4. Microrover Nanokhod enhancing the scientific output of the ExoMars Lander

    Science.gov (United States)

    Klinkner, Sabine; Bernhardt, Bodo; Henkel, Hartmut; Rodionov, Daniel; Klingelhoefer, Goestar

    The Nanokhod rover is a small and mobile exploration platform carrying out in-situ exploration by transporting and operating scientific instruments to interesting samples beyond the landing point. The microrover has a volume of 160x65x250mm (3) it weighs 3.2kg including a payload mass of 1kg and it has a peak power of 5W. The scientific model payload of the rover is a Geochemistry Instrument Package Facility (GIPF), which analyses the chemical and mineralogical composition of planetary surfaces. It consists of: An Alpha-Particle-Xray-spectrometer, a Mößbauer spectrometer and a miniature imaging system. The amount of science which can be performed within the operating range of the lander is limited since there are only few reachable, scientific interesting objects. By travelling to new sites with the aid of a microrover, the additional reach enhances the mission output and provides a significant increase in scientific return. The implementation of the Nanokhod rover on the ExoMars Lander increases its operating range by a radius of several meters, requiring only a minor mass impact of few kilograms. The Nanokhod rover is a tethered vehicle based on a Russian concept. It stays connected to the Lander via thin cables throughout the mission. This connection is used for power supply to the rover as well as the transmission of commands and scientific data. This solution minimises the communication unit and eliminates the power subsystems on the rover side, saving valuable mass and thus improving the payload to system mass ratio. By removing the power storage subsystem on the rover side, the mobile system provides a high thermal robustness and allows the system to easily survive Martian nights. The locomotion of the rover is provided by tracks. This is the optimised locomotion method on a soft and sandy surface for such a small, low-mass system, allowing even to negotiate steep slopes. The tracks enable a large contact surface of the vehicle, thus reducing its contact

  5. Characteristics of exo- polygalacturonase produced by irradiated Aspergillus niger and Trichoderma viride spores

    International Nuclear Information System (INIS)

    Out of 69 fungal isolates from nine pectin rich fresh fruit wastes-showed pectinolytic activity, two were the powerful and best. They were identified as Aspergillus niger and Trichoderma viride. Gamma irradiation of the spore suspensions of these two isolates (0- 3 kGy) stimulated the exo-polygalacturonase (PG) production. Treatment with 0.25 kGy and 0.25-0.50 kGy was found to be the best doses for inducing PG activity produced from T. viride and Asp. niger respectively . The enzyme characteristics were also studied. The optimum temperature of T. viride enzyme reaction was 5 C compared with 45 degree C for Asp. niger enzyme extract.The optimum incubation time of T. viride enzyme reaction was 70-80 min which greater than that of Asp. niger namely 60 min.The results of enzyme reaction ph revealed that the best PG activity was observed at ph 5.0 for the extract of the two fungal isolates. The stability of the enzyme was affected markedly by each of incubation temp., incubation period and ph value .A. niger and T. viride crude extract enzymes were stimulated with Mn2+ while Zn2+ and Ca2+ were inhibitors. The best volume of crude enzyme extract was 3.00 ml in case of T. viride while in case of A. niger was 2.00 ml. T. viride enzyme extract showed its highest enzyme activity with substrate concentration 1.5 % while that of A. niger was found to be 3.0%.

  6. Identification of endo- and exo-polygalacturonase activity in Lygus hesperus (Knight) salivary glands.

    Science.gov (United States)

    Celorio-Mancera, Maria de la Paz; Carl Greve, L; Teuber, Larry R; Labavitch, John M

    2009-02-01

    Polygalacturonase (PG) activity found in the salivary gland apparatus of the western tarnished plant bug (WTPB, Lygus hesperus Knight) has been thought to be the main chemical cause of the damage inflicted by this mirid when feeding on its plant hosts. Early viscosity and thermal stability studies of the PG activity in L. hesperus protein extracts were difficult to interpret. Thus, it has been suggested that one or more PG protein(s) with different hydrolytic modes of action are produced by this mirid. In order to understand the quantitative complexity of the WTPB salivary PG activity, PG purification from a protein extract from salivary glands excised from L. hesperus insects was performed using affinity and ion exchange chromatography. To elucidate the qualitative complexity of the purified PGs, the digestion products generated by the PGs were separated using high performance anion exchange chromatography with pulsed amperometric detection. At least five PG proteins were detected; these differing in terms of their glycosylation, mass-to-charge ratios, and/or molecular mass. The characterization of the products generated by these PGs showed that endo- and exo-acting PGs are produced by WTPB. Although none of the PGs was purified to homogeneity, the present work provides biochemical evidence of a multiplicity of PGs that degrade the pectin component of the plant tissue in different fashions. The implications of these findings affect the understanding of WTPB feeding damage and, potentially, help identify ways to control this important crop pest. Arch. Insect Biochem. Physiol. 2008. (c) 2008 Wiley-Liss, Inc. PMID:19085947

  7. Indicators and Methods to Understand Past Environments from ExoMars Rover Drills

    Science.gov (United States)

    Kereszturi, A.; Bradak, B.; Chatzitheodoridis, E.; Ujvari, G.

    2016-03-01

    Great advances are expected during the analysis of drilled material acquired from 2 m depth by ExoMars rover, supported by the comparison to local context, and the joint use of different instruments. Textural information might be less detailed relatively to what is usually obtained at outcrops during classical geological field work on the Earth, partly because of the lack of optical imaging of the borehole wall and also because the collected samples are crushed. However sub-mm scale layering and some other sedimentary features might be identified in the borehole wall observations, or in the collected sample prior to crushing, and also at nearby outcrops. The candidate landing sites provide different targets and focus for research: Oxia Planum requires analysis of phyllosilicates and OH content, at Mawrth Vallis the layering of various phyllosilicates and the role of shallow-subsurface leaching should be emphasized. At Aram Dorsum the particle size and fluvial sedimentary features will be interesting. Hydrated perchlorates and sulphates are ideal targets possibly at every landing sites because of OH retention, especially if they are mixed with smectites, thus could point to even ancient wet periods. Extensive use of information from the infrared wall scanning will be complemented for geological context by orbital and rover imaging of nearby outcrops. Information from the context is especially useful to infer the possible action of past H2O. Separation of the ice and liquid water effects will be supported by cation abundance and sedimentary context. Shape of grains also helps here, and composition of transported grains points to the weathering potential of the environment in general. The work on Mars during the drilling and sample analysis will provide brand new experience and knowledge for future missions.

  8. Demonstration Of Synthetic Exo-earth Detection In The Lab With Speckle Subtraction Techniques

    Science.gov (United States)

    Belikov, Ruslan; Give'on, A.; Savransky, D.; Pueyo, L.; Kern, B.; Kasdin, J.

    2007-12-01

    The problem of detecting and imaging earth-like exoplanets is hampered by the fact that wavefront error in the optics of a space telescope creates a speckle pattern that can swamp the exoplanet. The standard approach for dealing with speckles is to suppress them below the planet level by a deformable mirror using a wavefront control algorithm. However, such wavefront control may take a long time to achieve speckle suppression of 1010, the nominal contrast necessary for exo-earths, especially if the target star is dim. Furthermore, a very precise deformable mirror and electronics are required. In this paper, we present and demonstrate in the lab a method to detect planet light from amidst a brighter speckle pattern (as long as that pattern is stable), thus relaxing the requirement of 1010 speckle suppression. Furthermore, our detection is simultaneous with wavefront control and uses all the images taken in the course of wavefront control, saving valuable mission time. The method consists of (a) using the wavefront control estimate of the coherent speckle field to separate the speckles from the incoherent planet light, and (b) using a matched filter to reduce noise. No motion or rotation of the telescope is required for this method. The experiment was conducted on the High Contrast Imaging Testbed at the Jet Propulsion Lab using the Shaped Pupil coronagraph under 10% optical bandwidth. This work was funded in part by JPL contract 1254357 and the Michelson Science Center, and carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  9. Binaries and Globular Cluster Dynamics

    CERN Document Server

    Rasio, F A; Joshi, K J; Rasio, Frederic A.; Fregeau, John M.; Joshi, Kriten J.

    2001-01-01

    We summarize the results of recent theoretical work on the dynamical evolution of globular clusters containing primordial binaries. Even a very small initial binary fraction (e.g., 10%) can play a key role in supporting a cluster against gravothermal collapse for many relaxation times. Inelastic encounters between binaries and single stars or other binaries provide a very significant energy source for the cluster. These dynamical interactions also lead to the production of large numbers of exotic systems such as ultracompact X-ray binaries, recycled radio pulsars, double degenerate systems, and blue stragglers. Our work is based on a new parallel supercomputer code implementing Henon's Monte Carlo method for simulating the dynamical evolution of dense stellar systems in the Fokker-Planck approximation. This new code allows us to calculate very accurately the evolution of a cluster containing a realistic number of stars (N ~ 10^5 - 10^6) in typically a few hours to a few days of computing time. The discrete, s...

  10. Exoplanets Bouncing Between Binary Stars

    CERN Document Server

    Moeckel, Nickolas

    2012-01-01

    Exoplanetary systems are found not only among single stars, but also binaries of widely varying parameters. Binaries with separations of 100--1000 au are prevalent in the Solar neighborhood; at these separations planet formation around a binary member may largely proceed as if around a single star. During the early dynamical evolution of a planetary system, planet--planet scattering can eject planets from a star's grasp. In a binary, the motion of a planet ejected from one star has effectively entered a restricted three-body system consisting of itself and the two stars, and the equations of motion of the three body problem will apply as long as the ejected planet remains far from the remaining planets. Depending on its energy, escape from the binary as a whole may be impossible or delayed until the three-body approximation breaks down, and further close interactions with its planetary siblings boost its energy when it passes close to its parent star. Until then this planet may be able to transition from the ...

  11. The DREAMS payload on-board the Entry and descent Demonstrator Module of the ExoMars mission

    Science.gov (United States)

    Esposito, F.; Montmessin, F.; Debei, S.; Colombatti, G.; Harri, A.-M.; Pommereau, J.-P.; Wilson, C.; Aboudan, A.; Molfese, C.; Zaccariotto, M.; Mugnuolo, R.

    2012-04-01

    DREAMS (Dust characterization, Risk assessment and Environment Analyser on the Martian Surface) is the scientific payload selected by ESA and NASA for the accommodation on the Entry and descent Demonstrator Module (EDM) of the ExoMars mission to be launched in 2016. It is a meteorological station with the additional capability to perform measurements of the electric fields close to the surface of Mars. It is an autonomous system that includes its own battery for power supply. It is constituted by the following subsystems: MarsTem (thermometer), MetBaro (pressure sensor), MetHumi (humidity sensor), MetWind (2-D wind sensor), MicroARES (electric field sensor), ODS (optical depth sensor), a triaxial accelerometer (for attitude measurements), a CEU (Central Electronic Unit) and a battery. All systems in DREAMS have a solid heritage from other missions and have very high TRL. The ExoMars 2016 EDM mission is foreseen to reach Mars during the climatological dust storm season. DREAMS will have the unique chance of making scientific measurements able to characterize the martian environment in this dust loaded scenario. Even with low resources (volume, mass, energy) DREAMS will be able to perform novel measurements that will improve our understanding of the martian environment and dust cycle. DREAMS will perform: • Meteorological measurements by monitoring pressure, temperature, wind speed and direction, humidity and dust opacity during a martian sol at its landing site. • Characterization of the martian boundary layer. • Hazard monitoring by providing a comprehensive dataset to help engineers to quantify hazards for equipments and human crew: velocity of windblown dust, electrostatic charging, existence of discharges, and electromagnetic noise potentially affecting communications. • The first ever investigation of atmospheric electric phenomena on Mars. The DREAMS experiment gathers a wide consortium of institutions led by Italy, reflecting the current involvement

  12. Using Binary Code Instrumentation in Computer Security

    Directory of Open Access Journals (Sweden)

    Marius POPA

    2013-01-01

    Full Text Available The paper approaches the low-level details of the code generated by compilers whose format permits outside actions. Binary code modifications are manually done when the internal format is known and understood, or automatically by certain tools developed to process the binary code. The binary code instrumentation goals may be various from security increasing and bug fixing to development of malicious software. The paper highlights the binary code instrumentation techniques by code injection to increase the security and reliability of a software application. Also, the paper offers examples for binary code formats understanding and how the binary code injection may be applied.

  13. Search for Majoron-emitting modes of double-beta decay of $^{136}$Xe with EXO-200

    CERN Document Server

    :,; Auty, D J; Barbeau, P S; Beauchamp, E; Beck, D; Belov, V; Benitez-Medina, C; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Chaves, J; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, C G; Davis, J; DeVoe, R; Delaquis, S; Didberidze, T; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Hall, C; Herrin, S; Hughes, M; Jewell, M J; Jiang, X S; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Kuchenkov, A; Kumar, K S; Leonard, D S; Leonard, F; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Nelson, R; Odian, A; Ostrovskiy, I; Ouellet, C; Piepke, A; Pocar, A; Prescott, C Y; Rivas, A; Rowson, P C; Rozo, M P; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tosi, D; Tsang, R; Twelker, K; Vogel, P; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2014-01-01

    EXO-200 is a single phase liquid xenon detector designed to search for neutrinoless double-beta decay of $^{136}$Xe. Here we report on a search for various Majoron-emitting modes based on 100 kg$\\cdot$yr exposure of $^{136}$Xe. A lower limit of $T^{^{136}Xe}_{1/2} >1.2...10^{24}$ yr at 90% C.L. on the half-life of the spectral index = 1 Majoron decay was obtained, corresponding to a constraint on the Majoron-neutrino coupling constant of $||<$ (0.8-1.7)...10$^{-5}$.

  14. Reactivity of pentacoordinate ferrous porphyrins with exo-bidentate nitrogenous bases. Mononuclear and binuclear complexes in dynamic equilibrium

    International Nuclear Information System (INIS)

    The reaction of several exo-bidentate nitrogenous bases with thiocarbonyl(5,10,15,20-tetraphenylporphinato)iron(II) afforded six-coordinate mononuclear and binuclear porphyrin complexes in dynamic equilibrium. This reaction was carried out in halocarbon solvents and monitored both spectrally and electrochemically. Within the potential limits of the solvent/supporting electrolyte system, each complex underwent at least four separate electron-transfer reactions with retention of the thiocarbonyl ligand. An electron-transfer pathway is presented and supported by the combined results of infrared and electronic absorption spectra, variable-temperature proton NMR, variable-temperature electrochemical, and spectroelectrochemical experiments. 46 references, 5 figures, 2 tables

  15. DREAMS for the ExoMars 2016 mission: a suite of sensors for the characterization of Martian environment

    Science.gov (United States)

    Esposito, F.; Debei, S.; Bettanini, C.; Molfese, C.; Arruego Rodríguez, I.; Colombatti, G.; Harri, A.-M.; Montmessin, F.; Wilson, C.; Aboudan, A.; Zaccariotto, M.; Abaki, S.; Bellucci, G.; Berthelier, J.-J.; Brucato, J. R.; Calcutt, S. B.; Cortecchia, F.; Cucciarrè, F.; Di Achille, G.; Ferri, F.; Forget, F.; Frisco, E.; Genzer, M.; Gilbert, P.; Goutail, J.-P.; Haukka, H.; Jiménez, J. J.; Jiménez, S.; Josset, J.-L.; Karatekin, O.; Landis, G.; Lorentz, R.; Marthy, L.; Martinez, J.; Mennella, V.; Möhlmann, D.; Palomba, E.; Patel, M.; Pommereau, J.-P.; Popa, C. I.; Rafkin, S.; Rannou, P.; Renno, N. O.; Schipani, P.; Schmidt, W.; Segato, E.; Simoes, F.; Spiga, A.; Valero, F.; Vázquez, L.; Vivat, F.; Witasse, O.; Yahi, S.; Mugnuolo, R.; Pirrotta, S.

    2013-09-01

    The DREAMS package is a suite of sensors for the characterization of the Martian basic state meteorology and of the atmospheric electric properties at the landing site of the Entry, descent and landing Demonstration Module (EDM) of the ExoMars mission. The EDM will land on Meridiani Planum in October 2016, during the statistical dust storm season. This will allow DREAMS to investigate the status of the atmosphere of Mars during this particular season and also to understand the role of dust as a potential source of electrical phenomena on Mars. DREAMS will be the first instrument to perform a measurement of electric field on Mars.

  16. Anti-complementary Activities of Exo- and Endo-biopolymer Produced by Submerged Mycelial Culture of Eight Different Mushrooms

    OpenAIRE

    Yang, Byung-Keun; Gu, Young-Ah; Jeong, Yong-Tae; Song, Chi-Hyun

    2007-01-01

    The Elfvingia applanata (EA), Hericium erinaceum (HE),Grifola frondosa (GF), Pholiota nameko (PN), Pleurotus eryngii (PE), Trametes suaveolens (TS), Fomes fomentarius (FF), and Inonotus obliquus (IO) could produce the endo- (EN) and exo-biopolymer (EX) in submerged culture. The highest anti-complementary activity of the EN was exhibited by PN (49.1%), followed by HE (38.6%), TS (37.0%),and FF (33.0%),whereas the high activity of the EX was found with GF (59.8%),followed by HE (36.3%),TS (30.8...

  17. Modelling the performances of the WISDOM radar on the Oxia Planum potential landing site for ExoMars

    OpenAIRE

    Ciarletti, Valérie; Hervé, Yann; Dorizon, Sophie; Le Gall, Alice; Quantin, C.; Broyer, J.; Davis, J; Grindrod, P.

    2015-01-01

    The search for evidence of past or present life is the main objective of the ESA-Roscosmos ExoMars rover mission [1]. The rover will be equipped with a suite of instruments dedicated to the investigation and characterization of the surface and shallow subsurface of Mars. In particular, a drill will provide, for the first time, ground samples from a depth of approximately 2 meters and a Ground Penetrating Radar named WISDOM (Water Ice Subsurface Deposit Observations on Mars) will map the shall...

  18. Discovery of the 2 hour modulated X-ray source EXO 033319-2554.2, an AM Herculis system

    International Nuclear Information System (INIS)

    The discovery of EXO 033319-2554.2, a soft X-ray source modulated at a period of about 128 minutes, is reported. The bright part of the cycle lasts 0.55 in phase and is cut by an eclipse-like feature lasting eight minutes, with unresolved ingress and egress 0.13 after maximum intensity. The soft X-ray color requires blackbody temperatures less than 25 eV. The optical counterpart has a magnitude m(v) of roughly 18.5. These data imply that the object is an AM Her system. 31 references

  19. The structure of contact binaries

    CERN Document Server

    Kaehler, H

    2003-01-01

    In radiative layers of rotating stars the luminosity carried by circulation currents through a surface of constant entropy (circulation luminosity) is shown to be positive. The corresponding decrease in the temperature gradient is important in the secondary of contact binaries. This result removes the deadlock in the theory of contact binaries. The resulting treatment of contact binaries is investigated, assuming thermal equilibrium. If the circulation luminosity is adjusted to give a prescribed temperature difference between the components, details turn out to be unimportant. The temperature difference is bound to be positive. The fractional extent of radiative regions is larger in the secondary than in the primary. In the course of evolution the period increases and the mass ratio decreases. A survey of unevolved and evolved contact configurations is presented. Observational tests are passed. In stable systems the degree of contact is small. Stable systems in the period-colour diagram, unevolved and evolved...

  20. The ROP2-RIC7 pathway negatively regulates light-induced stomatal opening by inhibiting exocyst subunit Exo70B1 in Arabidopsis.

    Science.gov (United States)

    Hong, Daewoong; Jeon, Byeong Wook; Kim, Soo Young; Hwang, Jae-Ung; Lee, Youngsook

    2016-01-01

    Stomata are the tiny valves on the plant surface that mediate gas exchange between the plant and its environment. Stomatal opening needs to be tightly regulated to facilitate CO2 uptake and prevent excess water loss. Plant Rho-type (ROP) GTPase 2 (ROP2) is a molecular component of the system that negatively regulates light-induced stomatal opening. Previously, ROP-interactive Cdc42- and Rac-interactive binding motif-containing protein 7 (RIC7) was suggested to function downstream of ROP2. However, the underlying molecular mechanism remains unknown. To understand the mechanism by which RIC7 regulates light-induced stomatal opening, we analyzed the stomatal responses of ric7 mutant Arabidopsis plants and identified the target protein of RIC7 using a yeast two-hybrid screen. Light-induced stomatal opening was promoted by ric7 knockout, whereas it was inhibited by RIC7 overexpression, indicating that RIC7 negatively regulates stomatal opening in Arabidopsis. RIC7 interacted with exocyst subunit Exo70 family protein B1 (Exo70B1), a component of the vesicle trafficking machinery. RIC7 and Exo70B1 localized to the plasma membrane region under light or constitutively active ROP2 conditions. The knockout mutant of Exo70B1 and ric7/exo70b1 exhibited retarded light-induced stomatal opening. Our results suggest that ROP2 and RIC7 suppress excess stomatal opening by inhibiting Exo70B1, which most likely participates in the vesicle trafficking required for light-induced stomatal opening. PMID:26451971

  1. Practical Binary Adaptive Block Coder

    CERN Document Server

    Reznik, Yuriy A

    2007-01-01

    This paper describes design of a low-complexity algorithm for adaptive encoding/ decoding of binary sequences produced by memoryless sources. The algorithm implements universal block codes constructed for a set of contexts identified by the numbers of non-zero bits in previous bits in a sequence. We derive a precise formula for asymptotic redundancy of such codes, which refines previous well-known estimate by Krichevsky and Trofimov, and provide experimental verification of this result. In our experimental study we also compare our implementation with existing binary adaptive encoders, such as JBIG's Q-coder, and MPEG AVC (ITU-T H.264)'s CABAC algorithms.

  2. Coalescing binaries and Doppler experiments

    OpenAIRE

    Vecchio, A.; Bertotti, B.; Iess, L.

    1997-01-01

    We discuss the sensitivity of the CASSINI experiments to gravitational waves emitted by the in-spiral of compact binaries. We show that the maximum distance reachable by the instrument is $\\sim 100$ Mpc. In particular, CASSINI can detect massive black hole binaries with chirp mass $\\simgt 10^6 \\Ms$ in the Virgo Cluster with signal-to-noise ratio between 5 and 30 and possible compact objects of mass $\\simgt 30 \\Ms$ orbiting the massive black hole that our Galactic Centre is likely to harbour.

  3. Rectangular Decomposition of Binary Images

    Czech Academy of Sciences Publication Activity Database

    Suk, Tomáš; Höschl, Cyril; Flusser, Jan

    Berlin : Springer, 2012 - (Blanc-Talon, J.; Popescu, D.; Philips, W.; Scheunders, P.), s. 213-224 ISBN 978-3-642-33139-8. - (Lecture Notes in Computer Science. 7517). [Advanced Concepts for Intelligent Vision Systems (Acivs 2012). Brno (CZ), 04.09.2012-07.09.2012] R&D Projects: GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : binary image decomposition * generalized delta-method * distance transformation * quadtree * bipartite graph * image compression * fast convolution Subject RIV: IN - Informatics, Computer Science http://library.utia.cas.cz/separaty/2012/ZOI/suk-rectangular decomposition of binary images.pdf

  4. Kepler Eclipsing Binaries with Stellar Companions

    CERN Document Server

    Gies, D R; Guo, Z; Lester, K V; Orosz, J A; Peters, G J

    2015-01-01

    Many short-period binary stars have distant orbiting companions that have played a role in driving the binary components into close separation. Indirect detection of a tertiary star is possible by measuring apparent changes in eclipse times of eclipsing binaries as the binary orbits the common center of mass. Here we present an analysis of the eclipse timings of 41 eclipsing binaries observed throughout the NASA Kepler mission of long duration and precise photometry. This subset of binaries is characterized by relatively deep and frequent eclipses of both stellar components. We present preliminary orbital elements for seven probable triple stars among this sample, and we discuss apparent period changes in seven additional eclipsing binaries that may be related to motion about a tertiary in a long period orbit. The results will be used in ongoing investigations of the spectra and light curves of these binaries for further evidence of the presence of third stars.

  5. Frame theory for binary vector spaces

    OpenAIRE

    Bodmann, Bernhard G.; Le, My; Reza, Letty; Tobin, Matthew; Tomforde, Mark

    2009-01-01

    We develop the theory of frames and Parseval frames for finite-dimensional vector spaces over the binary numbers. This includes characterizations which are similar to frames and Parseval frames for real or complex Hilbert spaces, and the discussion of conceptual differences caused by the lack of a proper inner product on binary vector spaces. We also define switching equivalence for binary frames, and list all equivalence classes of binary Parseval frames in lowest dimensions, excluding cases...

  6. Using Binary Code Instrumentation in Computer Security

    OpenAIRE

    Marius POPA; Sergiu Marin CAPISIZU

    2013-01-01

    The paper approaches the low-level details of the code generated by compilers whose format permits outside actions. Binary code modifications are manually done when the internal format is known and understood, or automatically by certain tools developed to process the binary code. The binary code instrumentation goals may be various from security increasing and bug fixing to development of malicious software. The paper highlights the binary code instrumentation techniques by code injection to...

  7. Discs in misaligned binary systems

    Science.gov (United States)

    Rawiraswattana, Krisada; Hubber, David A.; Goodwin, Simon P.

    2016-08-01

    We perform SPH simulations to study precession and changes in alignment between the circumprimary disc and the binary orbit in misaligned binary systems. We find that the precession process can be described by the rigid-disc approximation, where the disc is considered as a rigid body interacting with the binary companion only gravitationally. Precession also causes change in alignment between the rotational axis of the disc and the spin axis of the primary star. This type of alignment is of great important for explaining the origin of spin-orbit misaligned planetary systems. However, we find that the rigid-disc approximation fails to describe changes in alignment between the disc and the binary orbit. This is because the alignment process is a consequence of interactions that involve the fluidity of the disc, such as the tidal interaction and the encounter interaction. Furthermore, simulation results show that there are not only alignment processes, which bring the components towards alignment, but also anti-alignment processes, which tend to misalign the components. The alignment process dominates in systems with misalignment angle near 90°, while the anti-alignment process dominates in systems with the misalignment angle near 0° or 180°. This means that highly misaligned systems will become more aligned but slightly misaligned systems will become more misaligned.

  8. A Galactic Binary Detection Pipeline

    Science.gov (United States)

    Littenberg, Tyson B.

    2011-01-01

    The Galaxy is suspected to contain hundreds of millions of binary white dwarf systems, a large fraction of which will have sufficiently small orbital period to emit gravitational radiation in band for space-based gravitational wave detectors such as the Laser Interferometer Space Antenna (LISA). LISA's main science goal is the detection of cosmological events (supermassive black hole mergers, etc.) however the gravitational signal from the galaxy will be the dominant contribution to the data - including instrumental noise over approximately two decades in frequency. The catalogue of detectable binary systems will serve as an unparalleled means of studying the Galaxy. Furthermore, to maximize the scientific return from the mission, the data must be "cleansed" of the galactic foreground. We will present an algorithm that can accurately resolve and subtract 2:: 10000 of these sources from simulated data supplied by the Mock LISA Data Challenge Task Force. Using the time evolution of the gravitational wave frequency, we will reconstruct the position of the recovered binaries and show how LISA will sample the entire compact binary population in the Galaxy.

  9. CFD Simulations of Binary Nucleation

    Czech Academy of Sciences Publication Activity Database

    Herrmann, E.; Brus, David; Hyvärinen, A-P.; Kulmala, M.

    Helsinki : -, 2010, P3U16. ISBN N. [International Aerosol Conference IAC 2010. Helsinki (FI), 29.08.2010-03.09.2010] Grant ostatní: FCR(FI) 1118615 Institutional research plan: CEZ:AV0Z40720504 Keywords : nucleation * binary * parameterization Subject RIV: CF - Physical ; Theoretical Chemistry www.iac2010.fi

  10. Eccentricity distribution of wide binaries

    CERN Document Server

    Tokovinin, Andrei

    2015-01-01

    A sample of 477 solar-type binaries within 67pc with projected separations larger than 50AU is studied by a new statistical method. Speed and direction of the relative motion are determined from the short observed arcs or known orbits, and their joint distribution is compared to the numerical simulations. By inverting the observed distribution with the help of simulations, we find that average eccentricity of wide binaries is 0.59+-0.02 and the eccentricity distribution can be modeled as f(e) ~= 1.2 e + 0.4. However, wide binaries containing inner subsystems, i.e. triple or higher-order multiples, have significantly smaller eccentricities with the average e = 0.52+-0.05 and the peak at e ~ 0.5. We find that the catalog of visual orbits is strongly biased against large eccentricities. A marginal evidence of eccentricity increasing with separation (or period) is found for this sample. Comparison with spectroscopic binaries proves the reality of the controversial period-eccentricity relation. The average eccentr...

  11. The PanCam Calibration Target (PCT) and multispectral image processing for the ExoMars 2018 mission

    Science.gov (United States)

    Barnes, D.; Wilding, M.; Gunn, M.; Tyler, L.; Pugh, S.; Coates, A.; Griffiths, A.; Cousins, C.; Schmitz, N.; Paar, G.

    2011-10-01

    The Panoramic Camera (PanCam) instrument for the ESA/NASA 2018 ExoMars mission is designed to be the 'eyes' of the Mars rover and is equipped with two wide angle multispectral cameras (WACs) from MSSL, and a focusable High Resolution Camera (HRC) from DLR. To achieve its science role within the ExoMars mission, the PanCam will generate terrain reflectance spectra to help identify the mineralogy of the Martian surface, and generate true-colour images of the Martian environment. The PanCam Calibration Target (PCT) is an essential component for the science operations of the PanCam instrument. Its purpose is to allow radiometric calibration and to support geometric calibration check-out of the PanCam instrument during the mission. Unlike other camera calibration targets flown to Mars, the PCT target regions are being made from stained glass. The paper describes the work undertaken during the early build and testing of the PCT, together with results from the baseline algorithms that have been designed and implemented to process the multispectral PanCam images.

  12. Computational comparative study of substitutional, endo and exo BN Co-Doped single walled carbon nanotube system

    Science.gov (United States)

    Shah, Khurshed A.; Parvaiz, M. Shunaid

    2016-05-01

    In this report we investigate the effect of doping on electronic properties of a zig-zag (4, 0) semi-conducting single walled two probe carbon nanotube system by using substitutional, endo and exo doping in the configuration. We choose atoms of elements Boron (B) and Nitrogen (N) because of their similar atomic radii to that of carbon. The Atomistic Tool Kit software (Version 13.8.1) and its graphical interface Virtual Nanolab is used in device mode for simulations. The calculations were carried out by using Huckel Parameters and the comparative study of current-voltage characteristics and conductance of the proposed models were done under low bias conditions. The results show that substitution doping has increased the conductance of the model than endo and exo. However, when the concentration of BN dopants is increased from two atom to four atom the endo doping model shows better performance than other two models. Hence the study is very beneficial for designing various CNT devices for commercial applications including amplifiers and oscillators.

  13. The structural basis for the exo-mode of action in GH74 oligoxyloglucan reducing end-specific cellobiohydrolase.

    Science.gov (United States)

    Yaoi, Katsuro; Kondo, Hidemasa; Hiyoshi, Ayako; Noro, Natsuko; Sugimoto, Hiroshi; Tsuda, Sakae; Mitsuishi, Yasushi; Miyazaki, Kentaro

    2007-06-29

    Oligoxyloglucan reducing end-specific cellobiohydrolase (OXG-RCBH) is a unique exo-beta-1,4-glucanase that belongs to glycoside hydrolase family 74. The enzyme recognizes the reducing end of xyloglucan oligosaccharides and releases two glucosyl residue segments from the reducing end of the main chain. Previously, we reported that OXG-RCBH consists of two seven-bladed beta-propeller domains. There is a large cleft between the two domains, and a unique loop encloses one side of the active site cleft. Here, we report the X-ray crystal structure of the OXG-RCBH-substrate complex determined to a resolution of 2.4 A. The substrate bound to the cleft, and its reducing end was arranged near the loop region that is believed to impart OXG-RCBH with its activity. We constructed a deletion mutant of the loop region and conducted a detailed analysis. A deletion mutant of the loop region showed endo-activity with altered substrate recognition. More specifically, cleavage occurred randomly instead of at specific sites, most likely due to the misalignment of the substrate within the subsite. We believe that the loop imparts unique substrate specificity with exo-mode hydrolysis in OXG-RCBH. PMID:17498741

  14. The Structural Basis of Substrate Recognition in an exo-b-d-glucosaminidase Involved in Chitosan Hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Van Bueren, A.; Ghinet, M; Gregg, K; Fleury, A; Brzezinski, R; Boraston, A

    2009-01-01

    Family 2 of the glycoside hydrolase classification is one of the largest families. Structurally characterized members of this family include enzymes with ?-galactosidase activity (Escherichia coli LacZ), ?-glucuronidase activity (Homo sapiens GusB), and ?-mannosidase activity (Bacteroides thetaiotaomicron BtMan2A). Here, we describe the structure of a family 2 glycoside hydrolase, CsxA, from Amycolatopsis orientalis that has exo-?-d-glucosaminidase (exo-chitosanase) activity. Analysis of a product complex (1.85 A resolution) reveals a unique negatively charged pocket that specifically accommodates the nitrogen of nonreducing end glucosamine residues, allowing this enzyme to discriminate between glucose and glucosamine. This also provides structural evidence for the role of E541 as the catalytic nucleophile and D469 as the catalytic acid/base. The structures of an E541A mutant in complex with a natural ?-1,4-d-glucosamine tetrasaccharide substrate and both E541A and D469A mutants in complex with a pNP-?-d-glucosaminide synthetic substrate provide insight into interactions in the + 1 subsite of this enzyme. Overall, a comparison with the active sites of other GH2 enzymes highlights the unique architecture of the CsxA active site, which imparts specificity for its cationic substrate.

  15. The Structural Basis of Substrate Recognition in an exo-beta-d-Glucosaminidase Involved in Chitosan Hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Lammerts van Bueren, A.; Ghinet, M; Gregg, K; Fleury, A; Brzezinski, R; Boraston, A

    2009-01-01

    Family 2 of the glycoside hydrolase classification is one of the largest families. Structurally characterized members of this family include enzymes with beta-galactosidase activity (Escherichia coli LacZ), beta-glucuronidase activity (Homo sapiens GusB), and beta-mannosidase activity (Bacteroides thetaiotaomicron BtMan2A). Here, we describe the structure of a family 2 glycoside hydrolase, CsxA, from Amycolatopsis orientalis that has exo-beta-D-glucosaminidase (exo-chitosanase) activity. Analysis of a product complex (1.85 A resolution) reveals a unique negatively charged pocket that specifically accommodates the nitrogen of nonreducing end glucosamine residues, allowing this enzyme to discriminate between glucose and glucosamine. This also provides structural evidence for the role of E541 as the catalytic nucleophile and D469 as the catalytic acid/base. The structures of an E541A mutant in complex with a natural beta-1,4-D-glucosamine tetrasaccharide substrate and both E541A and D469A mutants in complex with a pNP-beta-D-glucosaminide synthetic substrate provide insight into interactions in the +1 subsite of this enzyme. Overall, a comparison with the active sites of other GH2 enzymes highlights the unique architecture of the CsxA active site, which imparts specificity for its cationic substrate.

  16. A Redundant Binary Algorithm for RSA

    Institute of Scientific and Technical Information of China (English)

    施荣华

    1996-01-01

    The normal form and modified normal form for binary redundant representation are defined.A redundant binary algorithm to compute modular exponentiation for very large integers is proposed.It is shown that the proposed algorithm requires the minimum number of basic operations(modular multiplications)among all possible binary redundant representations.

  17. Competitive learning for binary valued data

    OpenAIRE

    Leisch, Friedrich; Weingessel, Andreas; Dimitriadou, Evgenia

    1998-01-01

    We propose a new approach for using online competitive learning on binary data. The usual Euclidean distance is replaced by binary distance measures, which take possible asymmetries of binary data into account and therefore provide a "different point of view" for looking at the data. The method is demonstrated on two artificial examples and applied on tourist marketing research data. (author's abstract)

  18. Russian contribution to ExoMars Trace Gas Orbiter: Atmospheric Chemistry Suite (ACS)

    Science.gov (United States)

    Shakun, Alexey; Korablev, Oleg; Trokhimovskiy, Alexander; Grigoriev, Alexey; Anufreychik, Konstantin; Fedorova, Anna; Ignatiev, Nikolay; Ivanov, Yuriy; Moshkin, Boris; Kalinnikov, Yuriy; Montmessin, Franck

    2016-04-01

    Atmospheric Chemistry Suite (ACS) is a part of science payload of Trace Gas Orbiter (TGO), ExoMars mission. This project developed by European Space Agency (ESA) in collaboration with Russian Space Agency (Roscosmos). Russian contribution to ExoMars TGO is the Proton rocket and two science instruments ACS (three infrared spectrometers) and FREND (neutron detector). ACS consists of three infrared spectrometers (ACS/NIR, ACS/MIR and ACS/TIRVIM) capable to take spectral measurements from near to thermal infrared range simultaneously or separately. Spectrometric channels of ACS share common mechanical, electrical, and thermal interfaces. Electronic box (ACS/BE) provides to spectrometric channels power and data transfer interfaces. SpaceWire link is used for science data transfer and MIL-1553 link - for commanding and housekeeping data transfer. The NIR channel is an echelle spectrometer with acousto-optic tunable filter (AOTF) for the selection of diffraction orders. ACS NIR is capable to perform nadir and occultation observations. NIR covers the spectral range of 0.7-1.7 μm with resolving power of ~25000. NIR will perform unique for TGO instruments nightglow science (searching for O2, OH, NO nightglow emissions on Mars). From the 1.38 μm band NIR will do water vapour mapping in nadir and H2O vertical profiling in solar occultations. High resolution NIR measurements of 1.27 μm O2(a1Δg) dayglow will supply indirect ozone observations on the dayside on nadir. In solar occultation mode, the O2 vertical profiles will be measured from the surface (in case of low dust activity) to the 40 km altitude based on 0.76 μm absorption band. Together with MIR channel in solar occultation NIR will support the measurements of CO2 density profiles (based on 1.43 μm band) and aerosols characterization from 0.7 to 4 μm. The wide spectral range will allow not just determine aerosol particle sizes and density at different altitudes, but also distinguish between dust and ice particles

  19. Is primaquine useful and safe as true exo-erythrocytic merontocidal, hypnozoitocidal and gametocidal antimalarial drug?

    Directory of Open Access Journals (Sweden)

    Francisco Javier López-Antuñano

    1999-10-01

    Full Text Available The main objective of this paper is to make available in a single document, a sequence of events that have been published on the biology of malaria parasites and their interaction with the human host, looking for arguments for effective and save treatment: what we know and what we would like to know about the effects of primaquine in order to justify its use in clinical and public health practice. The practicioner should be aware that the antimalarial activity, hemolytic and methemoglobinemic side effects, and detoxification of primaquine are all thought to depend on various biotransformation products of the drug. In spite of the universal use during over six decades, their site and mechanism of formation and degradation and their specific biologic effects remain very poorly understood in human beings. The mature gametocytes of P. falciparum are naturally resistant to chloroquine and other blood merontocides, but they are usually eliminated with a single dose of 1.315 mg/kg per os (p.o. of primaquine phosphate (equivalent to 0.75 mg-base. Rather than empirically, related with relapses frequency, dosage schedules should only be determined through consideration of the kinetics and dynamics of the drug and its effect on sporozoites, pre and exo-erythrocytic merontes, hypnozoites and gametocytes of P. vivax. Where medical care services are not available or not capable to detect glucose -6- phosphate dehydrogenese- (G-6-PD deficiencies and deleterious effects of the drug, we recommend not to use primaquine. Both, P. vivax primary clinical attack and P. vivax relapses, as and when they occur should be treated with a course of 10 mg/kg chloroquine-base p.o. Prevention of relapses is probably related to strain characteristics of P. vivax hypnozoites populations envolved. If well informed and qualified medical care workers decide to use primaquine in the absence of enzime defficiencies and are able to follow-up the clinical, toxicological and parasitic

  20. Permutation Entropy for Random Binary Sequences

    Directory of Open Access Journals (Sweden)

    Lingfeng Liu

    2015-12-01

    Full Text Available In this paper, we generalize the permutation entropy (PE measure to binary sequences, which is based on Shannon’s entropy, and theoretically analyze this measure for random binary sequences. We deduce the theoretical value of PE for random binary sequences, which can be used to measure the randomness of binary sequences. We also reveal the relationship between this PE measure with other randomness measures, such as Shannon’s entropy and Lempel–Ziv complexity. The results show that PE is consistent with these two measures. Furthermore, we use PE as one of the randomness measures to evaluate the randomness of chaotic binary sequences.

  1. The DREAMS Experiment of the ExoMars 2016 Mission for the Study of Martian Environment During the Dust Storm Season

    Science.gov (United States)

    Esposito, F.; Debei, S.; Bettanini, C.; Molfese, C.; Arruego Rodriguez, I.; Colombatti, G.; Harri, A. M.; Montmessin, F.; Wilson, C.; Aboudan, A.; Abbaki, S.; Apestigue, V.; Bellucci, G.; Berthelier, J. J.; Brucato, J. R.; Calcutt, S. B.; Cortecchia, F.; Cucciarrè, F.; Di Achille, G.; Ferri, F.; Forget, F.; Friso, E.; Genzer, M.; Haukka, H.; Jimènez, J. J.; Jimènez, S.; Josset, J. L.; Karatekin, O.; Landis, G.; Lorenz, R.; Marchetti, E.; Martinez, J.; Marty, L.; Mennella, V.; Möhlmann, D.; Moirin, D.; Molinaro, R.; Palomba, E.; Patel, M.; Pommereau, J. P.; Popa, C. I.; Rafkin, S.; Rannau, P.; Renno, N. O.; Schipani, P.; Schmidt, W.; Segato, E.; Silvestro, S.; Simoes, F.; Spiga, A.; Valero, F.; Vázquez, L.; Vivat, F.; Witasse, O.; Mugnuolo, R.; Pirrotta, S.

    2014-07-01

    DREAMS is a meteorological experiment with the additional capability to measure the electric properties of the atmosphere of Mars. It will fly to Mars aboard ExoMars 2016 mission. It will land on the planet during the dust storm season.

  2. The Mycoparasite Ampelomyces quisqualis Expresses exgA Encoding an exo-beta-1,3-Glucanase in Culture and During Mycoparasitism.

    Science.gov (United States)

    Rotem, Y; Yarden, O; Sztejnberg, A

    1999-08-01

    ABSTRACT Ampelomyces quisqualis, a mycoparasite of fungi causing powdery mildews, exhibited high levels of extracellular exo-beta-1,3-glucanase activity in culture compared with Neurospora crassa and Gliocladium roseum. A. quisqualis culture filtrates affected powdery mildew caused by Sphaerotheca fusca in a manner indicative of cell wall degradation, as determined by microscopic examination. A gene encoding an exo-beta-1,3-glucanase in A. quisqualis, designated exgA, was isolated and sequenced. The predicted polypeptide deduced from exgA had 46, 42, and 30% identity with amino acid sequences of Trichoderma harzianum exo-beta-1,3-glucanase and Cochliobolus carbonum EXG1 (both encoding exo-beta-1,3-glucanase) and T. harzianum bng13.1 (encoding an endo-beta-1,3-glucanase), respectively. The exgA gene had a predicted molecular mass of 84 kDa and a pI of 4.79. The gene was expressed during the late stages of growth in culture, and transcription was induced by fungal cell wall components. Transcript levels for exgA were present during late stages of hyperpar-asitism and were abundant along A. quisqualis mycelium and were slightly less abundant in A. quisqualis pycnidia. PMID:18944674

  3. Fascinating reactivity in gold catalysis: Synthesis of oxetenes through rare 4-exo-dig allene cyclization and infrequent β-hydride elimination

    OpenAIRE

    Alcaide, Benito; Almendros, Pedro; Del Campo, T.M.; Fernández, I.

    2011-01-01

    A novel reactivity in gold catalysis, namely the unusual preference for the 4-exo-dig cyclization in allene chemistry as well as the rare β-hydride elimination reaction, was uncovered starting from readily available allenols. © 2011 The Royal Society of Chemistry.

  4. 14-3-3 checkpoint regulatory proteins interact specifically with DNA repair protein human exonuclease 1 (hEXO1) via a semi-conserved motif

    DEFF Research Database (Denmark)

    Andersen, Sofie Dabros; Keijzers, Guido; Rampakakis, Emmanouil;

    2012-01-01

    Human exonuclease 1 (hEXO1) acts directly in diverse DNA processing events, including replication, mismatch repair (MMR), and double strand break repair (DSBR), and it was also recently described to function as damage sensor and apoptosis inducer following DNA damage. In contrast, 14-3-3 proteins...

  5. Remnants of compact binary mergers

    CERN Document Server

    Domainko, W

    2006-01-01

    We investigate the long-term evolution and observability of remnants originating from the merger of compact binary systems and discuss the differences to supernova remnants. Compact binary mergers expel much smaller amounts of mass at much higher velocities, as compared to supernovae, which will affect the dynamical evolution of their remnants. The ejecta of mergers consist of very neutron rich nuclei. Some of these neutron rich nuclei will produce observational signatures in form of gamma ray lines during their decay. The composition of the ejecta might even give interesting constraints about the internal structure of the neutron star. We further discuss the possibility that merger remnants appear as recently discovered 'dark accelerators' which are extended TeV sources which lack emission in other bands.

  6. Event Rates for Binary Inspiral

    CERN Document Server

    Kalogera, V

    2001-01-01

    Double compact objects (neutron stars and black holes) found in binaries with small orbital separations are known to spiral in and are expected to coalesce eventually because of the emission of gravitational waves. Such inspiral and merger events are thought to be primary sources for ground based gravitational-wave interferometric detectors (such as LIGO). Here, we present a brief review of estimates of coalescence rates and we examine the origin and relative importance of uncertainties associated with the rate estimates. For the case of double neutron star systems, we compare the most recent rate estimates to upper limits derived in a number of different ways. We also discuss the implications of the formation of close binaries with two non-recycled pulsars.

  7. Mars Organic Molecule Analyzer (MOMA) Mass Spectrometer Status and Science Operations on the ExoMars Rover

    Science.gov (United States)

    Brinckerhoff, W. B.; van Amerom, F. H. W.; Danell, R.; Pinnick, V. T.; Arevalo, R. D., Jr.; Li, X.; Hovmand, L.; Mahaffy, P. R.; Goetz, W.; Goesmann, F.; Steininger, H.

    2014-12-01

    The Mars Organic Molecule Analyzer (MOMA) investigation on the 2018 ExoMars rover will examine the chemical composition of samples acquired from depths of up to two meters below the martian surface, where organics may be protected from radiative and oxidative degradation. MOMA combines analyses of acquired drill fines via (i) pyrolysis gas chromatography mass spectrometry (GCMS) and (ii) Mars ambient laser desorption mass spectrometry (LDMS), enabled by a fast-valve capillary ion inlet system. This "dual source" approach gives MOMA unprecedented breadth of detection over a wide range of molecular weights and volatilities. Analysis of nonvolatile, higher-molecular weight organics such as carboxylic acids and peptides even in the presence of significant perchlorate concentrations is enabled by the extremely short (~1 ns) pulses of the desorption laser. Use of the MOMA ion trap's tandem mass spectrometry (MS/MS) mode permits selective focus on key species for isolation and controlled fragmentation, providing structural analysis capabilities. The flight-like engineering test unit (ETU) of MOMA's ion trap mass spectrometer has been put through a battery of tests to assure robustness of operation in the martian environment, to assess science performance, and to prepare for the flight model build under extremely sterile conditions as required by ExoMars. These tests have included coupling campaigns with advanced prototypes of the MOMA GC (provided by the University of Paris) and the MOMA tapping station, ovens, and laser (provided by MPS and LZH). Planning for science operations has expanded with the development of scripts for MOMA's various parameterized modes, including MS/MS. Given the limited duration of the baseline mission (218 sols), MOMA will benefit from a thorough characterization of its performance with a variety of Mars analog samples and a careful comparison with current science results from the SAM experiment on MSL. Such preparation will enable efficient

  8. HP3 on ExoMars - Cutting airbag cloths with the sharp tip of a mechanical mole

    Science.gov (United States)

    Krause, C.; Izzo, M.; Re, E.; Mehls, C.; Richter, L.; Coste, P.

    2009-04-01

    The HP3 - Heat Flow and Physical Properties Package - is planned to be one of the Humboldt lander-based instruments on the ESA ExoMars mission. HP3 will allow the measurement of the subsurface temperature gradient and physical as well as thermophysical properties of the subsurface regolith of Mars down to a depth of 5 meters. From these measurements, the planetary heat flux can be inferred. The HP³ instrument package consists of a mole trailing a package of thermal and electrical sensors into the regolith. Beside the payload elements Thermal Excitation and Measurement Suite and a Permittivity Probe the HP3 experiment includes sensors to detect the forward motion and the tilt of the HP3 payload compartment. The HP3 experiment will be integrated into the lander platform of the ExoMars mission. The original accommodation featured a deployment device or a robotic arm to place HP3 onto the soil outside the deflated lander airbags. To avoid adding such deployment devices, it was suggested that the HP3 mole should be capable of piercing the airbags under the lander. The ExoMars lander airbag is made of 4 Kevlar layers (2 abrasive and 2 bladders). A double fold of the airbag (a worst case) would represent a pile of 12 layers. An exploratory study has examined the possibility of piercing airbag cloths by adding sharp cutting blades on the tip of a penetrating mole. In the experimental setup representative layers were laid over a Mars soil simulant. Initial tests used a hammer-driven cutting tip and had moderate to poor results. More representative tests used a prototype of the HP3 mole and were fully successful: the default 4 layer configuration was pierced as well as the 12 layer configuration, the latter one within 3 hours and about 3000 mole strokes This improved behaviour is attributed to the use of representative test hardware where guidance and suppression of mole recoil were concerned. The presentation will provide an explanation of the technical requirements on

  9. Modified binary particle swam optimization

    Institute of Scientific and Technical Information of China (English)

    Sangwook Lee; Sangmoon Soak; Sanghoun Oh; Witold Pedrycz; Moongu Jeon

    2008-01-01

    This paper presents a modified binary particle swarm optimization(BPSO)which adopts concepts of the genotype-phenotype rep-resentation and the mutation operator of genetic algorithms.Its main feature is that the BPSO can be treated as a continuous PSO.The proposed BPSO algorithm is tested on various benchmark functions,and its performance is compared with that of the original BPSO.Experimental results show that the modified BPSO outperforms the original BPSO algorithm.

  10. Tides in asynchronous binary systems

    OpenAIRE

    Toledano, Oswaldo; Moreno, Edmundo; Koenigsberger, Gloria; Detmers, R.; Langer, Norbert

    2006-01-01

    Stellar oscillations are excited in non-synchronously rotating stars in binary systems due to the tidal forces. Tangential components of the tides can drive a shear flow which behaves as a differentially forced rotating structure in a stratified outer medium. In this paper we show that our single-layer approximation for the calculation of the forced oscillations yields results that are consistent with the predictions for the synchronization timescales in circular orbits. In addition, calibrat...

  11. The Global-Normal Disk Oscillations and the Persistent Low Frequency QPO in X-ray Binaries

    CERN Document Server

    Titarchuk, L G; Titarchuk, Lev; Osherovich, Vladimir

    2000-01-01

    We suggest that persistent low-frequency quasi-periodic oscillations (QPOs) detected in X-ray, ultraviolet, optical energy ranges the black hole (BH) sources XTE J1118+480, GRO J1655-40 LMC X-1 at ~ 0.1 Hz, and QPOs in HZ Her/Her X-1 at ~ 0.05 Hz and in Neutron Star (NS) binaries 4U 1323-62, 4U 1746-31 and EXO 0748-76 at ~ 1 Hz are caused by the global disk oscillations in the direction normal to the disk (normal mode). We argue that these disk oscillations are a result of the gravitational interaction between the central compact object and the disk. A small displacement of the disk from the equatorial plane results in a linear gravitational restoring force opposite to this displacement. Our analysis shows that the frequency of this mode is a function of the mass of the central object and it also depends on the inner and outer radii of the disk which in turn are related to the rotation period of the binary system. We derive an analytical formula for the frequency of the normal disk mode and show that these fr...

  12. Galaxy Rotation and Rapid Supermassive Binary Coalescence

    Science.gov (United States)

    Holley-Bockelmann, Kelly; Khan, Fazeel Mahmood

    2015-09-01

    Galaxy mergers usher the supermassive black hole (SMBH) in each galaxy to the center of the potential, where they form an SMBH binary. The binary orbit shrinks by ejecting stars via three-body scattering, but ample work has shown that in spherical galaxy models, the binary separation stalls after ejecting all the stars in its loss cone—this is the well-known final parsec problem. However, it has been shown that SMBH binaries in non-spherical galactic nuclei harden at a nearly constant rate until reaching the gravitational wave regime. Here we use a suite of direct N-body simulations to follow SMBH binary evolution in both corotating and counterrotating flattened galaxy models. For N > 500 K, we find that the evolution of the SMBH binary is convergent and is independent of the particle number. Rotation in general increases the hardening rate of SMBH binaries even more effectively than galaxy geometry alone. SMBH binary hardening rates are similar for co- and counterrotating galaxies. In the corotating case, the center of mass of the SMBH binary settles into an orbit that is in corotation resonance with the background rotating model, and the coalescence time is roughly a few 100 Myr faster than a non-rotating flattened model. We find that counterrotation drives SMBHs to coalesce on a nearly radial orbit promptly after forming a hard binary. We discuss the implications for gravitational wave astronomy, hypervelocity star production, and the effect on the structure of the host galaxy.

  13. Visual Binaries in the Orion Nebula Cluster

    CERN Document Server

    Reipurth, Bo; Connelley, Michael S; Bally, John

    2007-01-01

    We have carried out a major survey for visual binaries towards the Orion Nebula Cluster using HST images obtained with an H-alpha filter. Among 781 likely ONC members more than 60" from theta-1 Ori C, we find 78 multiple systems (75 binaries and 3 triples), of which 55 are new discoveries, in the range from 0.1" to 1.5". About 9 binaries are likely line-of-sight associations. We find a binary fraction of 8.8%+-1.1% within the limited separation range from 67.5 to 675 AU. The field binary fraction in the same range is a factor 1.5 higher. Within the range 150 AU to 675 AU we find that T Tauri associations have a factor 2.2 more binaries than the ONC. The binary separation distribution function of the ONC shows unusual structure, with a sudden steep decrease in the number of binaries as the separation increases beyond 0.5", corresponding to 225 AU. We have measured the ratio of binaries wider than 0.5" to binaries closer than 0.5" as a function of distance from the Trapezium, and find that this ratio is signifi...

  14. Impact of atmospheric refraction: How deeply can we probe exo-Earth's atmospheres during primary eclipse observations?

    CERN Document Server

    Betremieux, Y

    2013-01-01

    Most models used to predict or fit exoplanet transmission spectra do not include all the effects of atmospheric refraction. Namely, the angular size of the star with respect to the planet can limit the lowest altitude, or highest density, probed during primary eclipses, as no rays passing below this critical altitude can reach the observer. We discuss this geometrical effect of refraction and show that most habitable exo-Earths cannot be probed down to their surface. We present 0.4-5.0micron model transmission spectra of Earth's atmosphere viewed as a transiting exoplanet, and show how atmospheric refraction modifies the transmission spectrum depending on the spectral type (O5-M9) of the host star. We demonstrate that refraction is another phenomenon that can potentially explain flat transmission spectra over some spectral regions.

  15. Discovery of a BL Lacertae object (EXO 055625 - 3838.6) in the error box of H0557 - 385

    International Nuclear Information System (INIS)

    X-ray and optical data are presented of a new BL Lacertae type object (EXO 055625 - 3838.6) which has been serendipitously discovered in an EXOSAT CMA image and is located within the error box of HO557-385 (4U0557 - 38, 3A0557 - 383), a hard X-ray source previously identified with a Seyfert 1 galaxy. Although the soft X-ray flux of the BL Lac is 10 times higher than that of the Seyfert and the EXOSAT data are fully consistent with the BL Lac being the only counterpart of HO557 - 385, a substantial contribution to the hard X-ray flux from the Seyfert galaxy cannot be excluded. (author)

  16. The importance of chain conformational mobility during 5-exo-cyclizations of C-, N- and O-centred radicals.

    Science.gov (United States)

    Walton, John C

    2014-10-28

    The reaction coordinates of an archetypical set of 5-exo cyclizations of C-, N- and O-centred radicals were investigated by computational methods. G4 theory, and DFT with the um062x functional, were able to rationalise counterintuitive factors such as the 'normal' order of rate constants being: N-centred implied that rigidity at the N-ends of the chains, and the consequent extra energy needed to attain chair-like transition states, might be the reason for slow aminyl cyclizations. A novel linear correlation between cyclization activation energies and the access angles was discovered. The preference for cis-1,2-disubstituted product formation was also accounted for in terms of interaction between the hyperconjugatively delocalized SOMO and the alkene π* orbital. PMID:25179567

  17. NOMAD, a spectrometer suite for Nadir and Solar Occultation observations on the ExoMars Trace Gas Orbiter

    Science.gov (United States)

    Drummond, Rachel; Robert, Severine; Vandaele, Ann-Carine; Willame, Yannick; Lopez-Moreno, Jose Juan; Patel, Manish; Belluci, Giancarlo; Daerden, Frank; Neefs, Eddy; Rodriguez-Gomez, Julio

    2013-04-01

    NOMAD, the "Nadir and Occultation for MArs Discovery" spectrometer suite was selected as part of the payload of the ExoMars Trace Gas Orbiter mission 2016. This instrument suite will conduct a spectroscopic survey of Mars' atmosphere in the UV, visible and IR regions covering the 0.2-0.65 and 2.2-4.3 µm spectral ranges. NOMAD's observation modes include solar occultation, nadir and limb observations. The NOMAD instrument is composed of 3 channels: a solar occultation only channel (SO) operating in the infrared wavelength domain, a second infrared channel capable of doing nadir, but also solar occultation and limb observations (LNO), and an ultraviolet/visible channel (UVIS) that can work in all observation modes. The spectral resolution of SO and LNO surpasses previous surveys in the infrared by more than one order of magnitude. NOMAD offers an integrated instrument combination of a flight-proven concept (SO is a copy of SOIR on Venus Express), and innovations based on existing and proven instrumentation (LNO is based on SOIR/VEX and UVIS has heritage from the ExoMars lander), that will provide mapping and vertical profile information at high spatio-temporal resolution. The three channels have each their own ILS and optical bench, but share the same single interface to the S/C. We will present the instrument and its capabilities in term of detection of a broad suite of species, its possibilities to improve our knowledge on vertical structure of the atmosphere as well as its mapping possibilities. Since last year's abstract, much progress has been made on the instrument design and prototypes have been tested, especially concerning the very challenging thermal needs of the instrument. This paper will concentrate on the developments in the last year that prove NOMAD will be a very powerful, sensitive instrument.

  18. Sgs1 and Exo1 suppress targeted chromosome duplication during ends-in and ends-out gene targeting.

    Science.gov (United States)

    Štafa, Anamarija; Miklenić, Marina; Zunar, Bojan; Lisnić, Berislav; Symington, Lorraine S; Svetec, Ivan-Krešimir

    2014-10-01

    Gene targeting is extremely efficient in the yeast Saccharomyces cerevisiae. It is performed by transformation with a linear, non-replicative DNA fragment carrying a selectable marker and containing ends homologous to the particular locus in a genome. However, even in S. cerevisiae, transformation can result in unwanted (aberrant) integration events, the frequency and spectra of which are quite different for ends-out and ends-in transformation assays. It has been observed that gene replacement (ends-out gene targeting) can result in illegitimate integration, integration of the transforming DNA fragment next to the target sequence and duplication of a targeted chromosome. By contrast, plasmid integration (ends-in gene targeting) is often associated with multiple targeted integration events but illegitimate integration is extremely rare and a targeted chromosome duplication has not been reported. Here we systematically investigated the influence of design of the ends-out assay on the success of targeted genetic modification. We have determined transformation efficiency, fidelity of gene targeting and spectra of all aberrant events in several ends-out gene targeting assays designed to insert, delete or replace a particular sequence in the targeted region of the yeast genome. Furthermore, we have demonstrated for the first time that targeted chromosome duplications occur even during ends-in gene targeting. Most importantly, the whole chromosome duplication is POL32 dependent pointing to break-induced replication (BIR) as the underlying mechanism. Moreover, the occurrence of duplication of the targeted chromosome was strikingly increased in the exo1Δ sgs1Δ double mutant but not in the respective single mutants demonstrating that the Exo1 and Sgs1 proteins independently suppress whole chromosome duplication during gene targeting. PMID:25089886

  19. Evolution of binary stars in multiple-population globular clusters - II. Compact binaries

    Science.gov (United States)

    Hong, Jongsuk; Vesperini, Enrico; Sollima, Antonio; McMillan, Stephen L. W.; D'Antona, Franca; D'Ercole, Annibale

    2016-04-01

    We present the results of a survey of N-body simulations aimed at exploring the evolution of compact binaries in multiple-population globular clusters. We show that as a consequence of the initial differences in the structural properties of the first-generation (FG) and the second-generation (SG) populations and the effects of dynamical processes on binary stars, the SG binary fraction decreases more rapidly than that of the FG population. The difference between the FG and SG binary fraction is qualitatively similar to but quantitatively smaller than that found for wider binaries in our previous investigations. The evolution of the radial variation of the binary fraction is driven by the interplay between binary segregation, ionization and ejection. Ionization and ejection counteract in part the effects of mass segregation but for compact binaries the effects of segregation dominate and the inner binary fraction increases during the cluster evolution. We explore the variation of the difference between the FG and the SG binary fraction with the distance from the cluster centre and its dependence on the binary binding energy and cluster structural parameters. The difference between the binary fraction in the FG and the SG populations found in our simulations is consistent with the results of observational studies finding a smaller binary fraction in the SG population.

  20. Orbital eccentricities in primordial black holes binaries

    OpenAIRE

    Cholis, Ilias; Kovetz, Ely D.; Ali-Haïmoud, Yacine; Bird, Simeon; Kamionkowski, Marc; Muñoz, Julian B.; Raccanelli, Alvise

    2016-01-01

    It was recently suggested that the merger of $\\sim30\\,M_\\odot$ primordial black holes (PBHs) may provide a significant number of events in gravitational-wave observatories over the next decade, if they make up an appreciable fraction of the dark matter. Here we show that measurement of the eccentricities of the inspiralling binary black holes can be used to distinguish these binaries from those produced by more traditional astrophysical mechanisms. These PBH binaries are formed on highly ecce...

  1. Asteroid Systems: Binaries, Triples, and Pairs

    CERN Document Server

    Margot, Jean-Luc; Taylor, Patrick; Carry, Benoît; Jacobson, Seth

    2015-01-01

    In the past decade, the number of known binary near-Earth asteroids has more than quadrupled and the number of known large main belt asteroids with satellites has doubled. Half a dozen triple asteroids have been discovered, and the previously unrecognized populations of asteroid pairs and small main belt binaries have been identified. The current observational evidence confirms that small (20 km) binaries with small satellites are most likely created during large collisions.

  2. Relativistic Gravity and Binary Radio Pulsars

    OpenAIRE

    Kaspi, V. M.

    1999-01-01

    Following a summary of the basic principles of pulsar timing, we present a review of recent results from timing observations of relativistic binary pulsars. In particular, we summarize the status of timing observations of the much celebrated original binary pulsar PSR B1913+16, draw attention to the recent confirmation of strong evidence for geodetic precession in this system, review the recent measurement of multiple post-Keplerian binary parameters for PSR B1534+12, and describe the Parkes ...

  3. Microlensing Signature of Binary Black Holes

    Science.gov (United States)

    Schnittman, Jeremy; Sahu, Kailash; Littenberg, Tyson

    2012-01-01

    We calculate the light curves of galactic bulge stars magnified via microlensing by stellar-mass binary black holes along the line-of-sight. We show the sensitivity to measuring various lens parameters for a range of survey cadences and photometric precision. Using public data from the OGLE collaboration, we identify two candidates for massive binary systems, and discuss implications for theories of star formation and binary evolution.

  4. Detection of unresolved binaries with multicolor photometry

    CERN Document Server

    Chulkov, D; Malkov, O; Sichevskij, S; Krussanova, N; Mironov, A; Zakharov, A; Kniazev, A

    2016-01-01

    The principal goal of this paper is to specify conditions of detection of unresolved binaries by multicolor photometry. We have developed a method for estimating the critical distance at which an unresolved binary of given mass and age can be detected. The method is applied to the photometric system of the planned Lyra-B spaceborne experiment. We have shown that some types of unresolved binary stars can be discovered and distinguished from single stars solely by means of photometric observations.

  5. Relativistic Gravity and Binary Radio Pulsars

    CERN Document Server

    Kaspi, V M

    1999-01-01

    Following a summary of the basic principles of pulsar timing, we present a review of recent results from timing observations of relativistic binary pulsars. In particular, we summarize the status of timing observations of the much celebrated original binary pulsar PSR B1913+16, draw attention to the recent confirmation of strong evidence for geodetic precession in this system, review the recent measurement of multiple post-Keplerian binary parameters for PSR B1534+12, and describe the Parkes Multibeam survey, a major survey of the Galactic Plane which promises to discover new relativistic binary pulsar systems.

  6. Speech perception of noise with binary gains

    DEFF Research Database (Denmark)

    Wang, DeLiang; Kjems, Ulrik; Pedersen, Michael Syskind;

    2008-01-01

    For a given mixture of speech and noise, an ideal binary time-frequency mask is constructed by comparing speech energy and noise energy within local time-frequency units. It is observed that listeners achieve nearly perfect speech recognition from gated noise with binary gains prescribed by the i...... by the ideal binary mask. Only 16 filter channels and a frame rate of 100 Hz are sufficient for high intelligibility. The results show that, despite a dramatic reduction of speech information, a pattern of binary gains provides an adequate basis for speech perception....

  7. The equations for binary density and the binary stream of particles of electro conducting magnetic liquids

    International Nuclear Information System (INIS)

    In work on the basis of a method of the kinetic equations it is output the differential equations for binary density and a binary stream of particles of electro conducting magnetic liquids. These equations are the nonuniform equations of parabolic type. The solution of these equations completely feature existential behaviour of binary density and a binary stream of particles of electro conducting magnetic liquids, i.e. process of a structural relaxation. (author)

  8. Field validation of a Leishmania (Leishmania mexicana exo-antigens ELISA for diagnosing tegumentary leishmaniasis in regions of Leishmania (Viannia predominance

    Directory of Open Access Journals (Sweden)

    Killarney Ataide Soares

    2015-06-01

    Full Text Available Background: Several tests are performed to obtain better accuracy when diagnosing American tegumentary leishmaniasis (ATL. It is believed that antigens released via secretion, excretion and metabolism are more specific than are antigens released by the lysis of Leishmaniaparasites. Such antigens are known as exo-antigens (exo-Ag and are formed from products released by cultured parasites in a way that is similar to that in which they cause infections in hosts.Objective: We attempted to validate a Leishmania mexicanaELISA exo-Ag for ATL diagnosis in Midwestern Brazil.Methods: A total of 281 patients were included in the study. We analysed pre-treatment blood from 98 ATL patients; out of those, 85.7% and 14.3% had cutaneous and mucosal forms, respectively.Results: The exo-Ag accuracy was 83.99% (95% CI = 79.24-87.81 with a sensitivity value of 90.82% (95% CI = 83.46-95.09 and an overall specificity value of 80.33% (95% CI = 73.97-85.44. The positive predictive value and negative predictive value were 71.20% (95% CI = 62.72-78.41 and 94.23% (95% CI = 89.40-96.94, respectively. Among healthy controls, exo-Ag had a specificity of 91.25% (95% CI = 83.02-95.70; additionally, the test had specificity rates of 66.67% (95% CI = 46.71-82.03 in Chagas disease patients, 60.61% (95% CI = 43.68-75.32 in patients with rheumatic diseases, 76.92% (95% CI = 49.74-91.82 in pemphigus foliaceus patients, 87.50% (95% CI = 52.91-97.76 in leprosy patients, 87.50% (95% CI = 63.98-96.50 in VRDL-positive patients, and 77.78 (95% CI = 45.26-93.68 in deep mycosis patients.Conclusion: Based on the indicators of validity, we conclude that the results obtained in this study enable the recommendation of the exo-Ag ELISA for ATL diagnosis once it presented a reasonable accuracy compared to classical methods. Cost evaluations are necessary to completely define the role of this technique in large scale.

  9. Expression of exo-inulinase gene from Aspergillus niger 12 in E. coli strain Rosetta-gami B (DE3) and its characterization.

    Science.gov (United States)

    Yedahalli, Shreyas S; Rehmann, Lars; Bassi, Amarjeet

    2016-05-01

    Inulin is a linear carbohydrate polymer of fructose subunits (2-60) with terminal glucose units, produced as carbon storage in selected plants. It cannot directly be taken up by most microorganisms due to its large size, unless prior hydrolysis through inulinase enzymes occurs. The hydrolyzed inulin can be taken up by microbes and/or recovered and used industrially for the production of high fructose syrup, inulo-oligosaccharides, biofuel, and nutraceuticals. Cell-free enzymatic hydrolysis would be desirable for industrial applications, hence the recombinant expression, purification and characterization of an Aspergillus niger derived exo-inulinase was investigated in this study. The eukaroyototic exo-inulinase of Aspergillus niger 12 has been expressed, for the first time, in an E. coli strain [Rosetta-gami B (DE3)]. The molecular weight of recombinant exo-inulinase was estimated to be ∼81 kDa. The values of Km and Vmax of the recombinant exo-inulinase toward inulin were 5.3 ± 1.1 mM and 402.1 ± 53.1 µmol min(-1)  mg(-1) protein, respectively. Towards sucrose the corresponding values were 12.20 ± 1.6 mM and 902.8 ± 40.2 µmol min(-1)  mg(-1) protein towards sucrose. The S/I ratio was 2.24 ± 0.7, which is in the range of native inulinase. The optimum temperature and pH of the recombinant exo-inulinase towards inulin was 55°C and 5.0, while they were 50°C and 5.5 towards sucrose. The recombinant exo-inulinase activity towards inulin was enhanced by Cu(2+) and reduced by Fe(2+) , while its activity towards sucrose was enhanced by Co(2+) and reduced by Zn(2+) . © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:629-637, 2016. PMID:26833959

  10. Massive Stars in Interactive Binaries

    Science.gov (United States)

    St.-Louis, Nicole; Moffat, Anthony F. J.

    Massive stars start their lives above a mass of ~8 time solar, finally exploding after a few million years as core-collapse or pair-production supernovae. Above ~15 solar masses, they also spend most of their lives driving especially strong, hot winds due to their extreme luminosities. All of these aspects dominate the ecology of the Universe, from element enrichment to stirring up and ionizing the interstellar medium. But when they occur in close pairs or groups separated by less than a parsec, the interaction of massive stars can lead to various exotic phenomena which would not be seen if there were no binaries. These depend on the actual separation, and going from wie to close including colliding winds (with non-thermal radio emission and Wolf-Rayet dust spirals), cluster dynamics, X-ray binaries, Roche-lobe overflow (with inverse mass-ratios and rapid spin up), collisions, merging, rejuventation and massive blue stragglers, black-hole formation, runaways and gamma-ray bursts. Also, one wonders whether the fact that a massive star is in a binary affects its parameters compared to its isolated equivalent. These proceedings deal with all of these phenomena, plus binary statistics and determination of general physical properties of massive stars, that would not be possible with their single cousins. The 77 articles published in these proceedings, all based on oral talks, vary from broad revies to the lates developments in the field. About a third of the time was spent in open discussion of all participants, both for ~5 minutes after each talk and 8 half-hour long general dialogues, all audio-recorded, transcribed and only moderately edited to yield a real flavour of the meeting. The candid information in these discussions is sometimes more revealing than the article(s) that preceded them and also provide entertaining reading. The book is suitable for researchers and graduate students interested in stellar astrophysics and in various physical processes involved when

  11. Young and Waltzing Binary Stars

    Science.gov (United States)

    2001-10-01

    ADONIS Observes Low-mass Eclipsing System in Orion Summary A series of very detailed images of a binary system of two young stars have been combined into a movie . In merely 3 days, the stars swing around each other. As seen from the earth, they pass in front of each other twice during a full revolution, producing eclipses during which their combined brightness diminishes . A careful analysis of the orbital motions has now made it possible to deduce the masses of the two dancing stars . Both turn out to be about as heavy as our Sun. But while the Sun is about 4500 million years old, these two stars are still in their infancy. They are located some 1500 light-years away in the Orion star-forming region and they probably formed just 10 million years ago . This is the first time such an accurate determination of the stellar masses could be achieved for a young binary system of low-mass stars . The new result provides an important piece of information for our current understanding of how young stars evolve. The observations were obtained by a team of astronomers from Italy and ESO [1] using the ADaptive Optics Near Infrared System (ADONIS) on the 3.6-m telescope at the ESO La Silla Observatory. PR Photo 29a/01 : The RXJ 0529.4+0041 system before primary eclipse PR Photo 29b/01 : The RXJ 0529.4+0041 system at mid-primary eclipse PR Photo 29c/01 : The RXJ 0529.4+0041 system after primary eclipse PR Photo 29d/01 : The RXJ 0529.4+0041 system before secondary eclipse PR Photo 29e/01 : The RXJ 0529.4+0041 system at mid-secondary eclipse PR Photo 29f/01 : The RXJ 0529.4+0041 system after secondary eclipse PR Video Clip 06/01 : Video of the RXJ 0529.4+0041 system Binary stars and stellar masses Since some time, astronomers have noted that most stars seem to form in binary or multiple systems. This is quite fortunate, as the study of binary stars is the only way in which it is possible to measure directly one of the most fundamental quantities of a star, its mass. The mass of a

  12. The structures of binary compounds

    CERN Document Server

    Hafner, J; Jensen, WB; Majewski, JA; Mathis, K; Villars, P; Vogl, P; de Boer, FR

    1990-01-01

    - Up-to-date compilation of the experimental data on the structures of binary compounds by Villars and colleagues. - Coloured structure maps which order the compounds into their respective structural domains and present for the first time the local co-ordination polyhedra for the 150 most frequently occurring structure types, pedagogically very helpful and useful in the search for new materials with a required crystal structure. - Crystal co-ordination formulas: a flexible notation for the interpretation of solid-state structures by chemist Bill Jensen. - Recent important advances in unders

  13. Monitoring the Impacts of Wildfires on Forest Ecosystems and Public Health in the Exo-Urban Environment Using High-Resolution Satellite Aerosol Products from the Visible Infrared Imaging Radiometer Suite (VIIRS)

    OpenAIRE

    Amy K. Huff; Shobha Kondragunta; Hai Zhang; Hoff, Raymond M

    2015-01-01

    Increasing development of exo-urban environments and the spread of urbanization into forested areas is making humans and forest ecosystems more susceptible to the risks associated with wildfires. Larger and more damaging wildfires are having a negative impact on forest ecosystem services, and smoke from wildfires adversely affects the public health of people living in exo-urban environments. Satellite aerosol measurements are valuable tools that can track the evolution of wildfires and monito...

  14. R144 : a very massive binary likely ejected from R136 through a binary-binary encounter

    CERN Document Server

    Oh, Seungkyung; Banerjee, Sambaran

    2013-01-01

    R144 is a recently confirmed very massive, spectroscopic binary which appears isolated from the core of the massive young star cluster R136. The dynamical ejection hypothesis as an origin for its location is claimed improbable by Sana et al. due to its binary nature and high mass. We demonstrate here by means of direct N-body calculations that a very massive binary system can be readily dynamically ejected from a R136-like cluster, through a close encounter with a very massive system. One out of four N-body cluster models produces a dynamically ejected very massive binary system with a mass comparable to R144. The system has a system mass of $\\approx$ 355 Msun and is located at 36.8 pc from the centre of its parent cluster, moving away from the cluster with a velocity of 57 km/s at 2 Myr as a result of a binary-binary interaction. This implies that R144 could have been ejected from R136 through a strong encounter with an other massive binary or single star. In addition, we discuss all massive binaries and sin...

  15. Millisecond Pulsars in Close Binaries

    CERN Document Server

    Tauris, Thomas M

    2015-01-01

    In this Habilitationsschrift (Habilitation thesis) I present my research carried out over the last four years at the Argelander Institute for Astronomy (AIfA) and the Max Planck Institute for Radio Astronomy (MPIfR). The thesis summarizes my main findings and has been written to fulfill the requirements for the Habilitation qualification at the University of Bonn. Although my work is mainly focused on the topic of millisecond pulsars (MSPs), there is a fairly broad spread of research areas ranging from the formation of neutron stars (NSs) in various supernova (SN) events, to their evolution, for example, via accretion processes in binary and triple systems, and finally to their possible destruction in merger events. The thesis is organized in the following manner: A general introduction to neutron stars and millisecond pulsars is given in Chapter 1. A selection of key papers published in 2011-2014 are presented in Chapters 2-10, ordered within five main research areas (ultra-stripped SNe in close binaries, ma...

  16. Polarization in binary microlensing events

    International Nuclear Information System (INIS)

    The light received by source stars in microlensing events may be significantly polarized if both an efficient photon-scattering mechanism is active in the source stellar atmosphere and a differential magnification is therein induced by the lensing system. The best candidate events for observing polarization are highly magnified events with source stars belonging to the class of cool, giant stars in which the stellar light is polarized by photon scattering on dust grains contained in their envelopes. The presence in the stellar atmosphere of an internal cavity devoid of dust produces polarization profiles with a two peaks structure. Hence, the time interval between them gives an important observable quantity directly related to the size of the internal cavity and to the model parameters of the lens system. We show that, during a microlensing event, the expected polarization variability can solve an ambiguity that arises in some cases, related to the binary or planetary lensing interpretation of the perturbations observed near the maximum of the event light-curve. We consider a specific event case for which the parameter values corresponding to the two solutions are given. Then, assuming a polarization model for the source star, we compute the two expected polarization profiles. The position of the two peaks appearing in the polarization curves and the characteristic time interval between them allow us to distinguish between the binary and planetary lens solutions. (paper)

  17. ExoU contributes to late killing of Pseudomonas aeruginosa - infected endothelial cells ExoU contribui para a morte tardia de células endoteliais infectadas por Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Alessandra Mattos Saliba

    2003-11-01

    Full Text Available To ascertain the role of ExoU in late P. aeruginosa cytotoxicity, endothelial cells (EC were exposed to wild type PA103, PA103deltaexoU and PA103::exsA for 1h and to gentamicin in culture medium. After 24h, the viability of PA103-infected cells (33.7 ± 14.3% was significantly lower than the viability of PA103deltaexoU- (77.7 ± 6.3% or PA103::exsA- (79.5 ± 23.3% infected EC. P. aeruginosa cytotoxicity did not depend on the bacterial ability to interact with EC because the percentage of cells with associated PA103 (35.9 ± 15.8% was similar to the percentage in PA103deltaexoU- (34.2 ± 16.0% and lower than the percentage in PA103::exsA-infected cultures (82.9 ± 18.9%. Cell treatment with cytochalasin D reduced the PA103 internalization by EC but did not interfere with its ability to kill host cells.Para determinar o papel de ExoU na citotoxicidade tardia de P. aeruginosa, células endoteliais (CE foram expostas às cepas PA103, PA103deltaxoU e PA103::exsA por 1h e à gentamicina em meio de cultura. Após 24h, a viabilidade das CE infectadas com PA103 (33.7 ± 14.3% foi inferior à de CE infectadas com PA103deltaexoU (77.7 ± 6.3% e PA103::exsA (79.5 ± 23.3%. A citotoxicidade não dependeu da capacidade de interagir com as CE porque o percentual de células com bactérias associadas em culturas expostas a PA103 foi semelhante ao percentual em culturas expostas a PA103deltaexoU e inferior em culturas expostas a PA103::exsA. O tratamento das CE com citocalasina D reduziu a internalização de PA103, mas não interferiu em sua citotoxicidade.

  18. Pulsating Components in Binary and Multiple Stellar Systems --- A Catalog of Oscillating Binaries

    OpenAIRE

    Zhou, A. -Y.

    2010-01-01

    We present an up-to-date catalog of pulsating binaries, i.e. the binary and multiple stellar systems containing pulsating components, along with a statistics on them. Compared to the earlier compilation by Soydugan et al.(2006a) of 25 delta Scuti-type `oscillating Algol-type eclipsing binaries' (oEA), the recent collection of 74 oEA by Liakos et al.(2012), and the collection of Cepheids in binaries by Szabados (2003a), the numbers and types of pulsating variables in binaries are now extended....

  19. Potentials of mean force for the exo and endo solvolysis of 2-norbornyl chloride in water and DMSO: A constrained molecular dynamics study

    Indian Academy of Sciences (India)

    Subodh C Tiwari; Timir Hajari; Ashish Sharma; B L Tembe

    2012-01-01

    Constrained molecular dynamics is used to calculate the potentials of mean force for the exo and endo dissociation of 2-norbornyl chlorides in two solvents, namely water and dimethyl sulphoxide (DMSO). The gas phase potential energy curves for the 2-norbornyl chlorides are computed by ab initio methods and these curves are fitted into a 12-6-1 potential for use in classical molecular dynamics simulations. The gas phase potential energy curves indicate a greater barrier for the dissociation of the endo 2-norbornyl chloride (than the exo). The potentials of mean force (PMF) in DMSO and water indicate the locations and the magnitudes of the activation barriers in these solutions and are sensitive functions of the fitted gas phase potentials.

  20. Intramolecular carbolithiation cascades as a route to a highly strained carbocyclic framework: competition between 5-exo-trig ring closure and proton transfer

    Directory of Open Access Journals (Sweden)

    William F. Bailey

    2013-03-01

    Full Text Available The preparation of fairly strained carbocyclic ring systems by intramolecular 5-exo-trig ring closure has been well documented, and the absence of proton transfers that would compromise such cyclizations is a hallmark of this chemistry. In an effort to explore the limitations of this approach to more highly strained systems, the preparation of a stellane (tricyclo[3.3.0.03,7]octane framework by an intramolecular carbolithiation cascade involving three coupled 5-exo-trig cyclizations of the vinyllithium derived from 2-bromo-4-vinyl-1,6-heptadiene by lithium–bromine exchange was investigated. The cascade does not afford the stellane; rather, the cascade is terminated after two cyclizations by a proton transfer that occurs by an intermolecular process catalyzed by trace amounts of endo-5-methyl-2-methylenebicyclo[2.2.1]heptane present in reaction mixtures as a consequence of inadvertent quenching of an intermediate alkyllithium during prolonged reaction times at room temperature.

  1. The Evolution of Compact Binary Star Systems

    Directory of Open Access Journals (Sweden)

    Yungelson, Lev R.

    2006-12-01

    Full Text Available We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs, neutron stars (NSs, and black holes (BHs. Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA. Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.

  2. The Evolution of Compact Binary Star Systems

    Directory of Open Access Journals (Sweden)

    Konstantin A. Postnov

    2014-05-01

    Full Text Available We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs, neutron stars (NSs, and black holes (BHs. Mergings of compact-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks, which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to the formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically-important thermonuclear SN Ia. We also consider AM CVn-stars, which are thought to be the best verification binary GW sources for future low-frequency GW space interferometers.

  3. Eliciting Subjective Probabilities with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    We evaluate the binary lottery procedure for inducing risk neutral behavior in a subjective belief elicitation task. Harrison, Martínez-Correa and Swarthout [2013] found that the binary lottery procedure works robustly to induce risk neutrality when subjects are given one risk task defined over o...

  4. Pulsed Accretion onto Eccentric and Circular Binaries

    CERN Document Server

    Muñoz, Diego J

    2016-01-01

    We present numerical simulations of circumbinary accretion onto eccentric and circular binaries using the moving-mesh code AREPO. This is the first set of simulations to tackle the problem of binary accretion using a finite-volume scheme on a freely moving mesh, which allows for accurate measurements of accretion onto individual stars for arbitrary binary eccentricity. While accretion onto a circular binary shows bursts with period of ~5 times the binary period P_b,accretion onto an eccentric binary is predominantly modulated at the period ~1P_b. For an equal-mass circular binary, the accretion rates onto individual stars are quite similar to each other, following the same variable pattern in time. By contrast, for eccentric binaries, one of the stars can accrete at a rate 10-20 times larger than its companion. This "symmetry breaking" between the stars, however, alternates over timescales of order 200 P_b, and can be attributed to a slowly precessing, eccentric circumbinary disk. Over longer timescales, the ...

  5. ECCENTRIC EVOLUTION OF SUPERMASSIVE BLACK HOLE BINARIES

    International Nuclear Information System (INIS)

    In recent numerical simulations, it has been found that the eccentricity of supermassive black hole (SMBH)-intermediate black hole (IMBH) binaries grows toward unity through interactions with the stellar background. This increase of eccentricity reduces the merging timescale of the binary through the gravitational radiation to a value well below the Hubble time. It also gives a theoretical explanation of the existence of eccentric binaries such as that in OJ287. In self-consistent N-body simulations, this increase of eccentricity is always observed. On the other hand, the result of the scattering experiment between SMBH binaries and field stars indicated that the eccentricity dose not change significantly. This discrepancy leaves the high eccentricity of the SMBH binaries in N-body simulations unexplained. Here, we present a stellar-dynamical mechanism that drives the increase of the eccentricity of an SMBH binary with a large mass ratio. There are two key processes involved. The first one is the Kozai mechanism under a non-axisymmetric potential, which effectively randomizes the angular momenta of surrounding stars. The other is the selective ejection of stars with prograde orbits. Through these two mechanisms, field stars extract the orbital angular momentum of the SMBH binary. Our proposed mechanism causes the increase in the eccentricity of most of SMBH binaries, resulting in the rapid merger through gravitational wave radiation. Our result has given a definite solution to the 'last-parsec problem'.

  6. Microlensing Binaries with Candidate Brown Dwarf Companions

    DEFF Research Database (Denmark)

    Shin, I.-G; Han, C.; Gould, A.;

    2012-01-01

    Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing ...

  7. Gravitational radiation, inspiraling binaries, and cosmology

    Science.gov (United States)

    Chernoff, David F.; Finn, Lee S.

    1993-01-01

    We show how to measure cosmological parameters using observations of inspiraling binary neutron star or black hole systems in one or more gravitational wave detectors. To illustrate, we focus on the case of fixed mass binary systems observed in a single Laser Interferometer Gravitational-wave Observatory (LIGO)-like detector. Using realistic detector noise estimates, we characterize the rate of detections as a function of a threshold SNR Rho(0), H0, and the binary 'chirp' mass. For Rho(0) = 8, H0 = 100 km/s/Mpc, and 1.4 solar mass neutron star binaries, the sample has a median redshift of 0.22. Under the same assumptions but independent of H0, a conservative rate density of coalescing binaries implies LIGO will observe about 50/yr binary inspiral events. The precision with which H0 and the deceleration parameter q0 may be determined depends on the number of observed inspirals. For fixed mass binary systems, about 100 observations with Rho(0) = 10 in the LIGO will give H0 to 10 percent in an Einstein-DeSitter cosmology, and 3000 will give q0 to 20 percent. For the conservative rate density of coalescing binaries, 100 detections with Rho(0) = 10 will require about 4 yrs.

  8. Gravitational waves from inspiralling binary black holes

    International Nuclear Information System (INIS)

    Binary black holes are the most promising candidate sources for the first generation of earth-based interferometric gravitational-wave detectors. We summarize and discuss the state-of-the-art analytical techniques developed during the last few years to better describe the late dynamical evolution of binary black holes of comparable masses

  9. Bayesian analysis of exoplanet and binary orbits

    CERN Document Server

    Schulze-Hartung, Tim; Henning, Thomas

    2012-01-01

    We introduce BASE (Bayesian astrometric and spectroscopic exoplanet detection and characterisation tool), a novel program for the combined or separate Bayesian analysis of astrometric and radial-velocity measurements of potential exoplanet hosts and binary stars. The capabilities of BASE are demonstrated using all publicly available data of the binary Mizar A.

  10. Free radical 5-exo-dig cyclization as the key step in the synthesis of bis-butyrolactone natural products: experimental and theoretical studies

    OpenAIRE

    Sharma, Gangavaram V. M.; Harinada Chary, Devoju; Chandramouli, Nagula; Achrainer, Florian; Patrudu, Sateesh; Zipse, Hendrik

    2011-01-01

    Radical cyclization reactions were performed by 5-exo-dig mode to yield cis-fused bicyclic systems, leading to the synthesis of bis-butyrolactone class of natural products. The study was aimed at understanding the impact of alkyl side chains of furanoside ring systems in L-ara configuration on the radical cyclization. It was amply demonstrated by experimental studies that the increase in the length of the alkyl side chain has an effect on the cyclization: while efficient cyclization reactions...

  11. Survival and growth of yeast without telomere capping by Cdc13 in the absence of Sgs1, Exo1, and Rad9.

    Directory of Open Access Journals (Sweden)

    Hien-Ping Ngo

    2010-08-01

    Full Text Available Maintenance of telomere capping is absolutely essential to the survival of eukaryotic cells. Telomere capping proteins, such as Cdc13 and POT1, are essential for the viability of budding yeast and mammalian cells, respectively. Here we identify, for the first time, three genetic modifications that allow budding yeast cells to survive without telomere capping by Cdc13. We found that simultaneous inactivation of Sgs1, Exo1, and Rad9, three DNA damage response (DDR proteins, is sufficient to allow cell division in the absence of Cdc13. Quantitative amplification of ssDNA (QAOS was used to show that the RecQ helicase Sgs1 plays an important role in the resection of uncapped telomeres, especially in the absence of checkpoint protein Rad9. Strikingly, simultaneous deletion of SGS1 and the nuclease EXO1, further reduces resection at uncapped telomeres and together with deletion of RAD9 permits cell survival without CDC13. Pulsed-field gel electrophoresis studies show that cdc13-1 rad9Delta sgs1Delta exo1Delta strains can maintain linear chromosomes despite the absence of telomere capping by Cdc13. However, with continued passage, the telomeres of such strains eventually become short and are maintained by recombination-based mechanisms. Remarkably, cdc13Delta rad9Delta sgs1Delta exo1Delta strains, lacking any Cdc13 gene product, are viable and can grow indefinitely. Our work has uncovered a critical role for RecQ helicases in limiting the division of cells with uncapped telomeres, and this may provide one explanation for increased tumorigenesis in human diseases associated with mutations of RecQ helicases. Our results reveal the plasticity of the telomere cap and indicate that the essential role of telomere capping is to counteract specific aspects of the DDR.

  12. SYNTHESIS OF NOVEL CROWN ETHERS BEARING THE exo-cis-2,3-NORBORNYL GROUP AS POTENTIAL Na+ AND K+ EXTRACTANTS

    Energy Technology Data Exchange (ETDEWEB)

    Robeson, R.M.; Bonnesen, P.

    2007-01-01

    The synthesis of a series of novel dinorbornyl-16-crown-5 and dinorbornyl-18-crown-6 ethers that incorporate the exo-cis-2,3-norbornyl moiety within the macrocycle framework is described. The key starting material for the crown ethers, exo-cis-2,3-norbornanediol, was successfully prepared on a large (>30g) scale in 88% yield from norbornylene by osmium tetroxide-catalyzed hydroxylation. The syn and anti isomers of the dinorbornyl-16-crown-5 ether family were prepared using diethylene glycol with ring closure achieved using a methallyl linkage. The isomers cis-syn-cis and cis-anti-cis di-norbornano-15-methyleno-16-crown-5 (6A and 6B) could be separated using column chromatography, and a single crystal of the syn isomer 6A suitable for X-ray crystal structure analysis was obtained, thereby confi rming the syn orientation. The syn and anti isomers of the dinorbornyl-18-crown-6 ether family were successfully prepared employing a different synthetic strategy, involving the potassium–templated cyclization of two bis-hydroxyethoxy-substituted exo-cis-2,3-norbornyl groups under high dilution conditions. Attempts to fully separate cis-syn-cis di-norbornano-18-crown-6 (10A) and cis-anti-cis di-norbornano-18-crown-6 (10B) from one another using column chromatography were unsuccessful. All intermediates and products were checked for purity using either thin layer chromatography or gas chromatography, and characterized by proton and carbon NMR. Crown ethers 6AB and 10AB are to our knowledge the fi rst crown ethers to incorporate the exo-cis-2,3-norbornyl moiety into the crown ring to be successfully synthesized and characterized.

  13. Entwicklung und Schaffung eines in-situ Feuchtemessgerätes für den Mars im Zusammenhang mit der ESA Marsmission ExoMars

    OpenAIRE

    Koncz, Alexander

    2012-01-01

    Im Rahmen der vorliegenden Dissertation wurden mehrere Sensoren zur Detektion des atmosphärischen Wassergehaltes entwickelt und für ihren Einsatz auf dem Mars im Zuge der ESA ExoMars Mission optimiert und teilweise qualifiziert. Die Arbeiten am als MiniHUM bezeichneten Instrument umfassten sowohl die Charakterisierung und Entwicklung eines coulometrischen Sensorsystems als auch den Test und die Auswahl von kommerziell erhältlichen kapazitiven Polymerfeuchtesensoren. Zudem wurde ein Sensor zur...

  14. Planet Scattering Around Binaries: Ejections, Not Collisions

    CERN Document Server

    Smullen, Rachel A; Shannon, Andrew

    2016-01-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically effects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Asid...

  15. Orbital dynamics of binary boson star systems

    International Nuclear Information System (INIS)

    We extend our previous studies of head-on collisions of boson stars by considering orbiting binary boson stars. We concentrate on equal-mass binaries and study the dynamical behavior of boson/boson and boson/antiboson pairs. We examine the gravitational wave output of these binaries and compare with other compact binaries. Such a comparison lets us probe the apparent simplicity observed in gravitational waves produced by black hole binary systems. In our system of interest however, there is an additional internal freedom which plays a significant role in the system's dynamics, namely, the phase of each star. Our evolutions show rather simple behavior at early times, but large differences occur at late times for the various initial configurations

  16. Logistic chaotic maps for binary numbers generations

    International Nuclear Information System (INIS)

    Two pseudorandom binary sequence generators, based on logistic chaotic maps intended for stream cipher applications, are proposed. The first is based on a single one-dimensional logistic map which exhibits random, noise-like properties at given certain parameter values, and the second is based on a combination of two logistic maps. The encryption step proposed in both algorithms consists of a simple bitwise XOR operation of the plaintext binary sequence with the keystream binary sequence to produce the ciphertext binary sequence. A threshold function is applied to convert the floating-point iterates into binary form. Experimental results show that the produced sequences possess high linear complexity and very good statistical properties. The systems are put forward for security evaluation by the cryptographic committees.

  17. Surgery versus Active Monitoring in Intermittent Exotropia (SamExo: study protocol for a pilot randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Buck Deborah

    2012-10-01

    Full Text Available Abstract Background Childhood intermittent exotropia [X(T] is a type of strabismus (squint in which one eye deviates outward at times, usually when the child is tired. It may progress to a permanent squint, loss of stereovision and/or amblyopia (reduced vision. Treatment options for X(T include eye patches, glasses, surgery and active monitoring. There is no consensus regarding how this condition should be managed, and even when surgery is the preferred option clinicians disagree as to the optimal timing. Reports on the natural history of X(T are limited, and there is no randomised controlled trial (RCT evidence on the effectiveness or efficiency of surgery compared with active monitoring. The SamExo (Surgery versus Active Monitoring in Intermittent Exotropia pilot study has been designed to test the feasibility of such a trial in the UK. Methods Design: an external pilot patient randomised controlled trial. Setting: four UK secondary ophthalmology care facilities at Newcastle NHS Hospitals Foundation Trust, Sunderland Eye Infirmary, Moorfields Eye Hospital and York NHS Trust. Participants: children aged between 6 months and 16 years referred with suspected and subsequently diagnosed X(T. Recruitment target is a total of 144 children over a 9-month period, with 120 retained by 9-month outcome visit. Randomisation: permuted blocks stratified by collaborating centre, age and severity of X(T. Interventions: initial clinical assessment; randomisation (eye muscle surgery or active monitoring; 3-, 6- and 9-month (primary outcome clinical assessments; participant/proxy completed questionnaire covering time and travel costs, health services use and quality of life (Intermittent Exotropia Questionnaire; qualitative interviews with parents to establish reasons for agreeing or declining participation in the pilot trial. Outcomes: recruitment and retention rates; nature and extent of participation bias; nature and extent of biases arising from crossover or

  18. Polarization in binary microlensing events

    CERN Document Server

    Ingrosso, G; Nucita, A A; Strafella, F; Novati, S Calchi; Jetzer, Ph; Liuzzi, G; Zakharov, A

    2013-01-01

    The light received by source stars in microlensing events may be significantly polarized if both an efficient photon scattering mechanism is active in the source stellar atmosphere and a differential magnification is therein induced by the lensing system. The best candidate events for observing polarization are highly magnified events with source stars belonging to the class of cool, giant stars {in which the stellar light is polarized by photon scattering on dust grains contained in their envelopes. The presence in the stellar atmosphere of an internal cavity devoid of dust produces polarization profiles with a two peaks structure. Hence, the time interval between them gives an important observable quantity directly related to the size of the internal cavity and to the model parameters of the lens system.} We show that {during a microlensing event} the expected polarization variability can solve an ambiguity, that arises in some cases, related to the binary or planetary lensing interpretation of the perturba...

  19. Binary Cepheids from optical interferometry

    CERN Document Server

    Gallenne, A; Mérand, A; Monnier, J D; Pietrzyński, J Breitfelder G; Gieren, W

    2013-01-01

    Classical Cepheid stars have been considered since more than a century as reliable tools to estimate distances in the universe thanks to their Period-Luminosity (P-L) relationship. Moreover, they are also powerful astrophysical laboratories, providing fundamental clues for studying the pulsation and evolution of intermediate-mass stars. When in binary systems, we can investigate the age and evolution of the Cepheid, estimate the mass and distance, and constrain theoretical models. However, most of the companions are located too close to the Cepheid (1-40 mas) to be spatially resolved with a 10-meter class telescope. The only way to spatially resolve such systems is to use long-baseline interferometry. Recently, we have started a unique and long-term interferometric program that aims at detecting and characterizing physical parameters of the Cepheid companions, with as main objectives the determination of accurate masses and geometric distances.

  20. Binary theory of electronic stopping

    CERN Document Server

    Sigmund, P

    2002-01-01

    Binary stopping theory has been developed to characterize the electronic stopping of swift heavy ions in matter. It is an extension of Bohr's classical theory of 1913 incorporating screening, higher-order-Z sub 1 and shell corrections, high-speed quantum and relativity corrections as well as projectile excitation and ionization. The main numerical input comes from optical properties. The computation of shell corrections involves orbital velocity distributions of target and projectile electrons. Calculated stopping parameters depend on ion charge. Equilibrium stopping forces may be computed by adoption of a suitable model for the equilibrium charge state. This paper summarizes the current status of the theory, in particular the sensitivity of its predictions to pertinent input. Charge-dependent stopping forces have been calculated for selected systems and compared to experimental results. Equilibrium stopping forces calculated for a wide variety of ion-target combinations are compared with experimental data fr...

  1. Binary mixtures of chiral gases

    CERN Document Server

    Presilla, Carlo

    2015-01-01

    A possible solution of the well known paradox of chiral molecules is based on the idea of spontaneous symmetry breaking. At low pressure the molecules are delocalized between the two minima of a given molecular potential while at higher pressure they become localized in one minimum due to the intermolecular dipole-dipole interactions. Evidence for such a phase transition is provided by measurements of the inversion spectrum of ammonia and deuterated ammonia at different pressures. In particular, at pressure greater than a critical value no inversion line is observed. These data are well accounted for by a model previously developed and recently extended to mixtures. In the present paper, we discuss the variation of the critical pressure in binary mixtures as a function of the fractions of the constituents.

  2. Gamma-ray binaries and related systems

    CERN Document Server

    Dubus, Guillaume

    2013-01-01

    After initial claims and a long hiatus, it is now established that several binary stars emit high (0.1-100 GeV) and very high energy (>100 GeV) gamma rays. A new class has emerged called 'gamma-ray binaries', since most of their radiated power is emitted beyond 1 MeV. Accreting X-ray binaries, novae and a colliding wind binary (eta Car) have also been detected - 'related systems' that confirm the ubiquity of particle acceleration in astrophysical sources. Do these systems have anything in common ? What drives their high-energy emission ? How do the processes involved compare to those in other sources of gamma rays: pulsars, active galactic nuclei, supernova remnants ? I review the wealth of observational and theoretical work that have followed these detections, with an emphasis on gamma-ray binaries. I present the current evidence that gamma-ray binaries are driven by rotation-powered pulsars. Binaries are laboratories giving access to different vantage points or physical conditions on a regular timescale as ...

  3. Interrupted Binary Mass Transfer in Star Clusters

    CERN Document Server

    Leigh, Nathan W C; Toonen, Silvia

    2016-01-01

    Binary mass transfer is at the forefront of some of the most exciting puzzles of modern astrophysics, including Type Ia supernovae, gamma-ray bursts, and the formation of most observed exotic stellar populations. Typically, the evolution is assumed to proceed in isolation, even in dense stellar environments such as star clusters. In this paper, we test the validity of this assumption via the analysis of a large grid of binary evolution models simulated with the SeBa code. For every binary, we calculate analytically the mean time until another single or binary star comes within the mean separation of the mass-transferring binary, and compare this time-scale to the mean time for stable mass transfer to occur. We then derive the probability for each respective binary to experience a direct dynamical interruption. The resulting probability distribution can be integrated to give an estimate for the fraction of binaries undergoing mass transfer that are expected to be disrupted as a function of the host cluster pro...

  4. Measurements of the ion fraction and mobility of alpha and beta decay products in liquid xenon using EXO-200

    CERN Document Server

    Albert, J B; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, C G; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Hughes, M; Jewell, M J; Jiang, X S; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Nelson, R; O'Sullivan, K; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Robinson, A; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wright, J D; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2015-01-01

    Alpha decays in the EXO-200 detector are used to measure the fraction of charged $^{218}\\mathrm{Po}$ and $^{214}\\mathrm{Bi}$ daughters created from alpha and beta decays, respectively. $^{222}\\mathrm{Rn}$ alpha decays in liquid xenon (LXe) are found to produce $^{218}\\mathrm{Po}^{+}$ ions $50.3 \\pm 3.0\\%$ of the time, while the remainder of the $^{218}\\mathrm{Po}$ atoms are neutral. The fraction of $^{214}\\mathrm{Bi}^{+}$ from $^{214}\\mathrm{Pb}$ beta decays in LXe is found to be $76.4 \\pm 5.7\\%$, inferred from the relative rates of $^{218}\\mathrm{Po}$ and $^{214}\\mathrm{Po}$ alpha decays in the LXe. The average velocity of $^{218}\\mathrm{Po}$ ions is observed to decrease for longer drift times. Initially the ions have a mobility of $0.390 \\pm 0.006~\\mathrm{cm}^2/(\\mathrm{kV}~\\mathrm{s})$, and at long drift times the mobility is $0.219 \\pm 0.004~\\mathrm{cm}^2/(\\mathrm{kV}~\\mathrm{s})$. Time constants associated with the change in mobility during drift of the $^{218}\\mathrm{Po}^{+}$ ions are found to be propor...

  5. Optimization of hydroxyl radical scavenging activity of exo-polysaccharides from Inonotus obliquus in submerged fermentation using response surface methodology.

    Science.gov (United States)

    Chen, Hui; Xu, Xiangqun; Zhu, Yang

    2010-04-01

    The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exo-polysaccharides from Inonotus obliquus by response surface methodology. A two-level fractional factorial design was used to evaluate the effect of different components of medium. Corn flour, peptone, and KH2PO4 were important factors significantly affecting hydroxyl radical scavenging activity. These selected variables were subsequently optimized using path of steepest ascent (descent), a central composite design, and response surface analysis. The optimal medium composition was (% w/v): corn flour 5.30, peptone 0.32, KH2PO4 0.26, MgSO4 0.02, and CaCl2 0.01. Under the optimal condition, the hydroxyl radical scavenging rate (49.4%) was much higher than that using either basal fermentation medium (10.2%) and single variable optimization of fermentation medium (35.5%). The main monosaccharides components of the RSM optimized polysaccharides are rhamnose, arabinose, xylose, mannose, glucose and galactose with molar proportion at 1.45%, 3.63%, 2.17%, 15.94%, 50.00%, and 26.81%. PMID:20467262

  6. Timing and Spectral properties of Be/X-ray pulsar EXO 2030+375 during a Type I outburst

    CERN Document Server

    Naik, Sachindra; Jaisawal, Gaurava K; Paul, Biswajit

    2013-01-01

    We present results from a study of broadband timing and spectral properties of EXO 2030+375 using a Suzaku observation. Pulsations with a period of 41.41 s and strong energy dependent pulse profiles were clearly detected up to ~100 keV. Narrow dips are seen in the profiles up to ~70 keV. Presence of prominent dips at several phases in the profiles up to such high energy ranges were not seen before. At higher energies, these dips gradually disappeared and the profile appeared single-peaked. The 1.0-200.0 keV broad-band spectrum is found to be well described by a partial covering high energy cut-off power-law model. Several low energy emission lines are also detected in the pulsar spectrum. We fitted the spectrum using neutral as well as partially ionized absorbers along with above continuum model yielding similar parameter values. The partial covering with partially ionized absorber resulted into marginally better fit. The spectral fitting did not require any cyclotron feature in the best fit model. To investi...

  7. Evaluation of the effect of indigenous mycogenic silver nanoparticles on soil exo-enzymes in barite mine contaminated soils

    Science.gov (United States)

    Gaddam, Durga Prameela; Devamma, Nagalakshmi; Prasad, Tollamadugu Naga Venkata Krishna Vara

    2015-04-01

    The biosynthesis of nanoparticles has received increasing attention due to the growing need to develop safe, cost-effective and environmentally friendly technologies for nanoscale materials synthesis. In this report, silver nanoparticles (AgNPs) were synthesized by treating aqueous Ag+ ions with the culture supernatants of indigenous fungal species of Fusarium solani isolated from barite mine contaminated soils. The formation of AgNPs might be an enzyme-mediated extracellular reaction process. The localized surface plasmon resonance of the formed AgNPs was recorded using UV-VIS spectrophotometer and was characterized using the techniques transmission electron microscopy, particle size analyzer, Fourier transform-infrared spectroscopy (FT-IR), particle size (dynamic light scattering) and zeta potential. The synthesized AgNPs were stable, polydispersed with the average size of 80 nm. FT-IR spectra reveals that proteins and carboxylic groups present in the fungal secrets might be responsible for the reduction and stabilization of the silver ions. Applied to the barite mine contaminated soils, concentration of AgNPs and incubation period significantly influences the soil exo-enzymatic activities, viz., urease, phosphatase, dehydrogenase and β-glucosidase. To the best of our knowledge, this is the first report on this kind of work in barite mine contaminated soils.

  8. Azide anions inhibit GH-18 endochitinase and GH-20 Exo β-N-acetylglucosaminidase from the marine bacterium Vibrio harveyi.

    Science.gov (United States)

    Sirimontree, Paknisa; Fukamizo, Tamo; Suginta, Wipa

    2016-02-01

    Vibrio harveyi is a bioluminescent marine bacterium that utilizes chitin as its sole source of energy. In the course of chitin degradation, the bacterium primarily secretes an endochitinase A (VhChiA) to hydrolyze chitin, generating chitooligosaccharide fragments that are readily transported into the cell and broken down to GlcNAc monomers by an exo β-N-acetylglucosaminidase (VhGlcNAcase). Here we report that sodium salts, especially sodium azide, inhibit two classes of these chitin-degrading enzymes (VhChiA and VhGlcNAcase) with distinct modes of action. Kinetic analysis of the enzymatic hydrolysis of pNP-glycoside substrates reveals that sodium azide inhibition of VhChiA has a mixed-type mode, but that it inhibits VhGlcNAcase competitively. We propose that azide anions inhibit chitinase activity by acting as strong nucleophiles that attack Cγ of the catalytic Glu or Cβ of the neighbouring Asp residues. Azide anions may bind not only to the catalytic centre, but also to the other subsites in the substrate-binding cleft of VhChiA. In contrast, azide anions may merely occupy the small-binding pocket of VhGlcNAcase, thereby blocking the accessibility of its active site by short-chain substrates. PMID:26330565

  9. Characterization, Anti-Inflammatory and Antiproliferative Activities of Natural and Sulfonated Exo-Polysaccharides from Streptococcus thermophilus ASCC 1275.

    Science.gov (United States)

    Li, Siqian; Shah, Nagendra P

    2016-05-01

    Exo-polysaccharides (EPS) isolated from Streptococcus thermophilus ASCC 1275 were sulfated (31%). High-performance liquid chromatography identified that EPS was composed of mannose (30.19%), galactose (20.10%), glucose (18.05%), glucosamine (16.04%), galactosamine (9.06%), glucuronic acid (3.55%), and ribose (3.01%). Pro-/anti-inflammatory cytokine secretion ratios (IL-1β/IL-10, IL-6/IL-10, and TNF-α/IL-10) of lipopolysaccharide stimulated RAW 264.7 macrophages were significantly decreased by EPS and S.EPS treatments in a dose dependent manner. Furthermore, anti-inflammatory activities of S.EPS improved 49.3% and 24.0% than those of EPS before or after LPS treatment. The reactive oxygen species were inhibited by EPS and S.EPS by 49.6% and 55.1% at 50 μg/mL, respectively. Inhibition activities of S.EPS on nitric oxide production were 12.9% and 55.4% higher than those of EPS at 10 and 50 μg/mL. Additionally, S.EPS exhibited stronger antiproliferative activity on Caco-2 and HepG2 cells. Our results indicated that anti-inflammatory and antiproliferative activities of EPS were significantly (P < 0.01) improved by sulfonation. PMID:27010963

  10. Clouds in the Forecast? A Joint Spitzer and HST Investigation of Clouds and Hazes for Two Exo-Neptunes

    Science.gov (United States)

    Kreidberg, Laura; Morley, Caroline; Line, Michael; Stevenson, Kevin; Dragomir, Diana

    2016-08-01

    Recent observations of transiting planets have revealed that clouds and hazes are common in exoplanet atmospheres. Little is known, however, about how the clouds/hazes form, what their composition is, and how their properties vary with planet parameters. We propose to characterize the atmospheres of two exo-Neptunes, GJ 436b and GJ 3470b, both of which show evidence for clouds or hazes in their near-infrared spectra. We will measure precise 3.6 and 4.5 micron transit depths for these planets, to compare with existing high-precision data at shorter wavelengths. We will also obtain a UV spectrum for GJ 3470 with HST/COS to enable accurate models of the planet's photochemistry. These observations will enable us to distinguish at high confidence between a range of physically realistic models for the atmospheric chemistry, including methanogenic photochemical hazes and equilibrium salt/sulfide clouds. The measurements will enable comparative planetology with the handful of other small, cool worlds currently accessible to observation, and serve as a first assessment of the prevalence, origin, and composition of clouds and haze in metal-enriched atmospheres below 1000 K. Our findings will guide the design of future observations of increasingly Earth-like worlds with JWST.

  11. Impact of atmospheric refraction: how deeply can we probe exo-earth's atmospheres during primary eclipse observations?

    Energy Technology Data Exchange (ETDEWEB)

    Bétrémieux, Yan [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Kaltenegger, Lisa, E-mail: betremieux@mpia.de [Also at Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. (United States)

    2014-08-10

    Most models used to predict or fit exoplanet transmission spectra do not include all the effects of atmospheric refraction. Namely, the angular size of the star with respect to the planet can limit the lowest altitude, or highest density and pressure, probed during primary eclipses as no rays passing below this critical altitude can reach the observer. We discuss this geometrical effect of refraction for all exoplanets and tabulate the critical altitude, density, and pressure for an exoplanet identical to Earth with a 1 bar N{sub 2}/O{sub 2} atmosphere as a function of both the incident stellar flux (Venus, Earth, and Mars-like) at the top of the atmosphere and the spectral type (O5-M9) of the host star. We show that such a habitable exo-Earth can be probed to a surface pressure of 1 bar only around the coolest stars. We present 0.4-5.0 μm model transmission spectra of Earth's atmosphere viewed as a transiting exoplanet, and show how atmospheric refraction modifies the transmission spectrum depending on the spectral type of the host star. We demonstrate that refraction is another phenomenon that can potentially explain flat transmission spectra over some spectral regions.

  12. Pd-Si binary bulk metallic glass

    Institute of Scientific and Technical Information of China (English)

    YAO KeFu; CHEN Na

    2008-01-01

    Pd80+xSi20-x (x=0, 1, and 2) binary metallic glasses with the diameter ranging from 7 to 8 mm were prepared by a combination of fluxing and water quenching or air cooling. Thermal analysis results show that with increasing Si content, the glass transition temperature Tg, the initial crystallization temperature Tx and the onset crystalliza-tion temperature Tp of Pd-Si binary glassy alloys increase. Moreover, the super-cooled liquid region reaches 61 K. It indicates that Pd-Si binary alloys possess large glass forming ability, which can be greatly improved by fluxing treatment.

  13. Pd-Si binary bulk metallic glass

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Pd80+xSi20-x (x=0,1,and 2) binary metallic glasses with the diameter ranging from 7 to 8 mm were prepared by a combination of fluxing and water quenching or air cooling. Thermal analysis results show that with increasing Si content,the glass transition temperature Tg,the initial crystallization temperature Tx and the onset crystalliza-tion temperature Tp of Pd-Si binary glassy alloys increase. Moreover,the super-cooled liquid region reaches 61 K. It indicates that Pd-Si binary alloys possess large glass forming ability,which can be greatly improved by fluxing treatment.

  14. Eliciting Subjective Probabilities with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2014-01-01

    We evaluate a binary lottery procedure for inducing risk neutral behavior in a subjective belief elicitation task. Prior research has shown this procedure to robustly induce risk neutrality when subjects are given a single risk task defined over objective probabilities. Drawing a sample from the...... same subject population, we find evidence that the binary lottery procedure also induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation of subjective probabilities in subjects with...

  15. Cassini states for black hole binaries

    OpenAIRE

    Correia, Alexandre C. M.

    2015-01-01

    Cassini states correspond to the equilibria of the spin axis of a body when its orbit is perturbed. They were initially described for planetary satellites, but the spin axes of black hole binaries also present this kind of equilibria. In previous works, Cassini states were reported as spin-orbit resonances, but actually the spin of black hole binaries is in circulation and there is no resonant motion. Here we provide a general description of the spin dynamics of black hole binary systems base...

  16. Fast algorithms for generating binary holograms

    CERN Document Server

    Stuart, Dustin; Kuhn, Axel

    2014-01-01

    We describe three algorithms for generating binary-valued holograms. Our methods are optimised for producing large arrays of tightly focussed optical tweezers for trapping particles. Binary-valued holograms allow us to use a digital mirror device (DMD) as the display element, which is much faster than other alternatives. We describe how our binary amplitude holograms can be used to correct for phase errors caused by optical aberrations. Furthermore, we compare the speed and accuracy of the algorithms for both periodic and arbitrary arrangements of traps, which allows one to choose the ideal scheme depending on the circumstances.

  17. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    International Nuclear Information System (INIS)

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results

  18. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Haghighipour, Nader [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States); Kaltenegger, Lisa [MPIA, Koenigstuhl 17, Heidelberg, D-69117 (Germany)

    2013-11-10

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results.

  19. Compact Binaries in Star Clusters I - Black Hole Binaries Inside Globular Clusters

    OpenAIRE

    Downing, J. M. B.; Benacquista, M. J.; Giersz, M.; Spurzem, R.

    2009-01-01

    We study the compact binary population in star clusters, focusing on binaries containing black holes, using a self-consistent Monte Carlo treatment of dynamics and full stellar evolution. We find that the black holes experience strong mass segregation and become centrally concentrated. In the core the black holes interact strongly with each other and black hole-black hole binaries are formed very efficiently. The strong interactions, however, also destroy or eject the black hole-black hole bi...

  20. Properties of planets in binary systems. The role of binary separation

    OpenAIRE

    Desidera, S.; Barbieri, M.

    2006-01-01

    The statistical properties of planets in binaries were investigated. Any difference to planets orbiting single stars can shed light on the formation and evolution of planetary systems. As planets were found around components of binaries with very different separation and mass ratio, it is particularly important to study the characteristics of planets as a function of the effective gravitational influence of the companion. A compilation of planets in binary systems was made; a search for compa...

  1. Binaries in the Hipparcos data: Keep digging

    CERN Document Server

    Pourbaix, D; Jorissen, A

    2004-01-01

    Among the 120 000 objects in the Hipparcos catalogue, only 235 were fitted with an orbital model. Besides these 235 original astrometric binaries, most Hipparcos entries with a known spectroscopic orbit (extrasolar planet or stellar companion) have now been re-processed, as part of the on-going construction of the 9th Catalogue of Spectroscopic Binary Orbits (SB9, available at http://sb9.astro.ulb.ac.be). The pitfalls and successes of this re-processing are discussed in various contexts, like (i) orbital inclinations: the holy grail for extrasolar planets (ii) searching for binaries without a priori knowledge of their spectroscopic orbital elements, and application to barium stars (iii) why not all SB9 entries yield acceptable astrometric solutions? The lessons learned from this study are useful to devise the best possible binary-detection and orbit-determination algorithms for future astrometric missions like GAIA.

  2. A mesoscopic model for binary fluids

    CERN Document Server

    Echeverria, C; Alvarez-Llamoza, O; Orozco-Guillén, E E; Morales, M; Cosenza, M G

    2016-01-01

    We propose a model to study symmetric binary fluids, based in the mesoscopic molecular simulation technique known as multiparticle collision, where space and state variables are continuous while time is discrete. We include a repulsion rule to simulate segregation processes that does not require the calculation of the interaction forces between particles, thus allowing the description of binary fluids at a mesoscopic scale. The model is conceptually simple, computationally efficient, maintains Galilean invariance, and conserves the mass and the energy in the system at micro and macro scales; while momentum is conserved globally. For a wide range of temperatures and densities, the model yields results in good agreement with the known properties of binary fluids, such as density profile, width of the interface, phase separation and phase growth. We also apply the model to study binary fluids in crowded environments with consistent results.

  3. Red-giant stars in eccentric binaries

    Directory of Open Access Journals (Sweden)

    Beck P. G.

    2015-01-01

    Full Text Available The unparalleled photometric data obtained by NASA’s Kepler Space Telescope has led to improved understanding of red-giant stars and binary stars. We discuss the characterization of known eccentric system, containing a solar-like oscillating red-giant primary component. We also report several new binary systems that are candidates for hosting an oscillating companion. A powerful approach to study binary stars is to combine asteroseimic techniques with light curve fitting. Seismology allows us to deduce the properties of red giants. In addition, by modeling the ellipsoidal modulations we can constrain the parameters of the binary system. An valuable independent source are ground-bases, high-resolution spectrographs.

  4. Evolution of Binary Stars in Multiple-Population Globular Clusters - II. Compact Binaries

    CERN Document Server

    Hong, Jongsuk; Sollima, Antonio; McMillan, Stephen L W; D'Antona, Franca; D'Ercole, Annibale

    2016-01-01

    We present the results of a survey of N-body simulations aimed at exploring the evolution of compact binaries in multiple-population globular clusters.We show that as a consequence of the initial differences in the structural properties of the first-generation (FG) and the second-generation (SG) populations and the effects of dynamical processes on binary stars, the SG binary fraction decreases more rapidly than that of the FG population. The difference between the FG and SG binary fraction is qualitatively similar to but quantitatively smaller than that found for wider binaries in our previous investigations.The evolution of the radial variation of the binary fraction is driven by the interplay between binary segregation, ionization and ejection. Ionization and ejection counteract in part the effects of mass segregation but for compact binaries the effects of segregation dominate and the inner binary fraction increases during the cluster evolution. We explore the variation of the difference between the FG an...

  5. Tidal capture formation of Low Mass X-Ray Binaries from wide binaries in the field

    CERN Document Server

    Michaely, Erez

    2015-01-01

    We present a potentially efficient dynamical formation scenario for Low Mass X-ray Binaries (LMXBs) in the field, focusing on black-hole (BH) LMXBs. In this formation channel LMXBs are formed from wide binaries $(>1000$ AU) with a BH component and a stellar companion. The wide binary is perturbed by fly-by's of field stars and its orbit random-walks and changes over time. This diffusion process can drive the binary into a sufficiently eccentric orbit such that the binary components tidally interact at peri-center and the binary evolves to become a short period binary, which eventually evolves into an LMXB. The formation rate of LMXBs through this channel mostly depends on the number of such BH wide binaries progenitors, which in turn depends on the velocity kicks imparted to BHs (or NSs) at birth. We consider several models for the formation and survival of such wide binaries, and calculate the LMXB formation rates for each model. We find that models where BHs form through direct collapse with no/little natal...

  6. Binary is Good: A Binary Inference Framework for Primary User Separation in Cognitive Radio Networks

    CERN Document Server

    Nguyen, Huy; Han, Zhu

    2010-01-01

    Primary users (PU) separation concerns with the issues of distinguishing and characterizing primary users in cognitive radio (CR) networks. We argue the need for PU separation in the context of collaborative spectrum sensing and monitor selection. In this paper, we model the observations of monitors as boolean OR mixtures of underlying binary latency sources for PUs, and devise a novel binary inference algorithm for PU separation. Simulation results show that without prior knowledge regarding PUs' activities, the algorithm achieves high inference accuracy. An interesting implication of the proposed algorithm is the ability to effectively represent n independent binary sources via (correlated) binary vectors of logarithmic length.

  7. Dixie Valley Bottoming Binary Unit

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Dale [Terra-Gen Sierra Holdings, LLC, Reno, NV (United States)

    2014-12-21

    This binary plant is the first air cooled, high-output refrigeration based waste heat recovery cycle in the industry. Its working fluid is environmentally friendly and as such, the permits that would be required with a hydrocarbon based cycle are not necessary. The unit is largely modularized, meaning that the unit’s individual skids were assembled in another location and were shipped via truck to the plant site. The Air Cooled Condensers (ACC), equipment piping, and Balance of Plant (BOP) piping were constructed at site. This project further demonstrates the technical feasibility of using low temperature brine for geothermal power utilization. The development of the unit led to the realization of low temperature, high output, and environmentally friendly heat recovery systems through domestic research and engineering. The project generates additional renewable energy, resulting in cleaner air and reduced carbon dioxide emissions. Royalty and tax payments to governmental agencies will increase, resulting in reduced financial pressure on local entities. The major components of the unit were sourced from American companies, resulting in increased economic activity throughout the country.

  8. Structure of simple (binary) oxides

    International Nuclear Information System (INIS)

    Crystal structures of different simple and binary oxides of M3O, M2O, MO, MO2, MO4, MO3, M2O3, M3O4, M2O5, M2O7 composition as well as lowest cesium oxides (Cs7O, Cs4O, Cs11O3) are considered. Cs3O crystals are constructed out of the colomns of the Cs3O composition consisting of octahedrals OCs6 jointed through the opposite faces. This is the ZrI3 ''antistructure''. Cs2O has the CdCl2 antistructure. ZrO2, HfO2, CeO2, ThO2, UO2, NpO2, PuO2, AmO2, CmO2, PoO2 oxides have the structural type of fluorite of rutile - VO2, NbO2, TaO2, MoO2, ReO2 oxides, of wurtzite - BeO. The NbO oxide is unique, in its structure the oxygen and niobium atoms form four complanar bonds. A three-dimensional skeleton constructed out of the octahedral structural units Nb6 (Nb-Nb 2.98 A) is separated. ZrO2 is a polymorphous, at 1100 grad. the monoclinic modification transfers to tetragonal. M2O7 oxides are Re2O7, Tc2O7

  9. Detecting Eccentric Globular Cluster Binaries with LISA

    OpenAIRE

    Benacquista, M.

    2001-01-01

    The energy carried in the gravitational wave signal from an eccentric binary is spread across several harmonics of the orbital frequency. The inclusion of the harmonics in the analysis of the gravitational wave signal increases the signal-to-noise ratio of the detected signal for binaries whose fundamental frequency is below the galactic confusion-limited noise cut-off. This can allow for an improved angular resolution for sources whose orbital period is greater than 2000 s. Globular cluster ...

  10. Copula-based bivariate binary response models

    OpenAIRE

    Winkelmann, Rainer

    2009-01-01

    The bivariate probit model is frequently used for estimating the effect of an endogenous binary regressor on a binary outcome variable. This paper discusses simple modifications that maintain the probit assumption for the marginal distributions while introducing non-normal dependence among the two variables using copulas. Simulation results and evidence from two applications, one on the effect of insurance status on ambulatory expenditure and one on the effect of completing high school on sub...

  11. Binary compact object inspiral: Detection expectations

    Indian Academy of Sciences (India)

    Vassiliki Kalogera

    2004-10-01

    We review the current estimates of binary compact object inspiral rates in particular in view of the recently discovered highly relativistic binary pulsar J0737-3039. One of the robust results is that, because of this discovery, the rate estimates for binary neutron stars have increased by a factor of 6-7 independent of any uncertainties related to the pulsar population properties. This rate increase has dramatic implications for gravitational wave detectors. For initial LIGO, the most probable detection rates for double neutron star (DNS) inspirals is 1 event/(5{250) yr; at 95% confidence we obtain rates up to 1/1.5 yr. For advanced LIGO, the most probable rates are 20-1000 events/yr. These predictions, for the first time, bring the expectations for DNS detections by initial LIGO to the astrophysically relevant regime. We also use our models to predict that the large-scale Parkes multibeam pulsar survey with acceleration searches could detect an average of three to four binary pulsars similar to those known at present. In comparison, rate estimates for binaries with black holes are derived based on binary evolution calculation, and based on the optimistic ends of the ranges, remain an important candidate for inspiral detection in the next few years. We also consider another aspect of the detectability of binary inspiral: the effect of precession on the detection efficiency of astrophysically relevant binaries. Based on our current astrophysical expectations, large tilt angles are not favored. As a result the decrease in detection rate varies rather slowly with black hole spin magnitude and is within 20-30% of the maximum possible values.

  12. Planet Scattering Around Binaries: Ejections, Not Collisions

    OpenAIRE

    Smullen, Rachel A.; Kratter, Kaitlin M.; Shannon, Andrew

    2016-01-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in...

  13. GAIA survey of galactic eclipsing binaries

    OpenAIRE

    Zwitter, Tomaz

    2002-01-01

    General importance and capabilities of observations of eclipsing binaries by the forthcoming ESA mission GAIA are discussed. Availability of spectroscopic observations and a large number of photometric bands on board will make it possible to reliably determine physical parameters for $\\sim 10^5$ binary stars. It is stressed that current methods of object by object analysis will have to be modified and included in an automatic analysis pipeline.

  14. Formation of Compact Binaries in Globular Clusters

    OpenAIRE

    Rappaport, Saul; Pfahl, Eric; Rasio, Fred; Podsiadlowski, Philipp

    2001-01-01

    We report here on two complementary population synthesis studies which relate directly to the formation and evolution of neutron star binaries in globular clusters. In the first, we compute the probability of retaining neutron stars in globular clusters, and quantitatively confirm the idea that the retention fraction for neutron stars born in binary systems is greatly enhanced over those born in isolated stars. However, the retention fraction may well be insufficient to explain the current po...

  15. Diffusion in ordered binary solid systems

    International Nuclear Information System (INIS)

    This thesis contains contributions to the field of diffusion in ordered binary solid systems. An extensive experimental investigation of the self diffusion in CoGa is presented. The results of these diffusion measurements strongly suggest that a substantial part of the atomic migration is caused by a new type of defect. A quantitative description of the atomic displacements via this defect is given. Finally computer simulations are presented of diffusion and ordering in binary solid systems. (Auth.)

  16. Binary nature of the Barium stars

    International Nuclear Information System (INIS)

    We present radial-velocity spectrometer observations that indicate that Ba II stars are binary systems. The secondary stars of these systems have low masses, consistent with their being degenerate objects which have lost mass onto their primaries in a previous stage of evolution. It is suggested that the Population II equivalents, the CH stars, may also be binary systems. This may be related to the fact that they are found only in globular clusters of the lowest central concentration

  17. On homogeneous nontransitive binary perfect code

    OpenAIRE

    Mogilnykh, I. Yu.; Solov'eva, F. I.

    2014-01-01

    Studying binary perfect codes we show the existence of homogeneous nontransitive codes. Thus, as far as perfect codes are concerned, the propelinear codes are strictly contained in transitive codes, wheresas homogeneous codes form a strict subclass of transitive codes. In the work we deduce a necessary and sufficient condition for transitivity of perfect binary codes of rank one more than that of Hamming code. The paper is in Russian.

  18. Texture classification by texton: statistical versus binary.

    Science.gov (United States)

    Guo, Zhenhua; Zhang, Zhongcheng; Li, Xiu; Li, Qin; You, Jane

    2014-01-01

    Using statistical textons for texture classification has shown great success recently. The maximal response 8 (Statistical_MR8), image patch (Statistical_Joint) and locally invariant fractal (Statistical_Fractal) are typical statistical texton algorithms and state-of-the-art texture classification methods. However, there are two limitations when using these methods. First, it needs a training stage to build a texton library, thus the recognition accuracy will be highly depended on the training samples; second, during feature extraction, local feature is assigned to a texton by searching for the nearest texton in the whole library, which is time consuming when the library size is big and the dimension of feature is high. To address the above two issues, in this paper, three binary texton counterpart methods were proposed, Binary_MR8, Binary_Joint, and Binary_Fractal. These methods do not require any training step but encode local feature into binary representation directly. The experimental results on the CUReT, UIUC and KTH-TIPS databases show that binary texton could get sound results with fast feature extraction, especially when the image size is not big and the quality of image is not poor. PMID:24520346

  19. Texture classification by texton: statistical versus binary.

    Directory of Open Access Journals (Sweden)

    Zhenhua Guo

    Full Text Available Using statistical textons for texture classification has shown great success recently. The maximal response 8 (Statistical_MR8, image patch (Statistical_Joint and locally invariant fractal (Statistical_Fractal are typical statistical texton algorithms and state-of-the-art texture classification methods. However, there are two limitations when using these methods. First, it needs a training stage to build a texton library, thus the recognition accuracy will be highly depended on the training samples; second, during feature extraction, local feature is assigned to a texton by searching for the nearest texton in the whole library, which is time consuming when the library size is big and the dimension of feature is high. To address the above two issues, in this paper, three binary texton counterpart methods were proposed, Binary_MR8, Binary_Joint, and Binary_Fractal. These methods do not require any training step but encode local feature into binary representation directly. The experimental results on the CUReT, UIUC and KTH-TIPS databases show that binary texton could get sound results with fast feature extraction, especially when the image size is not big and the quality of image is not poor.

  20. Direct Exoplanet Detection with Binary Differential Imaging

    CERN Document Server

    Rodigas, Timothy J; Mamajek, Eric E; Males, Jared R; Close, Laird M; Morzinski, Katie; Hinz, Philip M; Kaib, Nathan

    2015-01-01

    Binaries are typically excluded from direct imaging exoplanet surveys. However, the recent findings of Kepler and radial velocity programs show that planets can and do form in binary systems. Here, we suggest that visual binaries offer unique advantages for direct imaging. We show that Binary Differential Imaging (BDI), whereby two stars are imaged simultaneously at the same wavelength within the isoplanatic patch at high Strehl ratio, offers improved point spread function (PSF) subtraction that can result in increased sensitivity to planets close to each star. We demonstrate this by observing a young visual binary separated by 4\\asec ~with MagAO/Clio-2 at 3.9 \\microns, where the Strehl ratio is high, the isoplanatic patch is large, and giant planets are bright. Comparing BDI to angular differential imaging (ADI), we find that BDI's 5$\\sigma$ contrast is \\about 0.5 mags better than ADI's within \\about 1\\asec ~for the particular binary we observed. Because planets typically reside close to their host stars, BD...

  1. Spectroscopic Orbits for Kepler FOV Eclipsing Binaries

    Science.gov (United States)

    Matson, Rachel A.; Gies, Douglas R.; Williams, Stephen J.; Guo, Zhao

    2013-02-01

    We are currently involved in a four year program of precise eclipsing binary photometry with the NASA Kepler Observatory. Our goal is to search for variations in minimum light timing for intermediate mass eclipsing binaries. Such periodic variations will reveal the reflex motion caused by any distant, low mass object that orbits the close binary. it Kepler's unprecedented accuracy and continuous observations provide a unique opportunity to detect the low mass companions that are predicted to result from the angular momentum of the natal cloud. The goal of this proposal is to obtain blue spectra of short period (0.9-6d) eclipsing binaries, derive radial velocities, and produce a double-lined spectroscopic orbit (as well as estimates of the stellar effective temperatures, gravities, and metallicities). Combined with the it Kepler light curve, we will determine very accurate masses and radii for the members of the close binary, which will yield the mass-inclination product M_3 sin i for any companions detected by light travel time or other effects. An extended sample of eclipsing binaries with longer periods (up to 50d) is now being investigated to test whether the presence of a tertiary companion declines with increasing period. We propose to obtain a single spectrum at quadrature for the brightest 48 stars in this expanded sample to characterize the effective temperatures and total mass contained in these systems.

  2. Stability and Coalescence of Massive Twin Binaries

    CERN Document Server

    Hwang, Jason A; Rasio, Frederic A; Kalogera, Vassiliki

    2015-01-01

    Massive stars are usually found in binaries, and binaries with periods less than 10 days may have a preference for near equal component masses. In this paper we investigate the evolution of these binaries all the way to contact and the possibility that these systems can be progenitors of double neutron star binaries. The small orbital separations of observed double neutron star binaries suggest that the progenitor systems underwent a common envelope phase at least once during their evolution. Bethe & Brown (1998) proposed that massive binary twins will undergo a common envelope evolution while both components are ascending the red giant branch or asymptotic giant branch simultaneously, also known as double-core evolution. Using models generated from the stellar evolution code Evolve Zero Age Main Sequence, we determine the range of mass ratios resulting in both components simultaneously ascending the RGB or AGB as a function of the difference in birth times, t. We find that, even for a generous t=5 Myr, t...

  3. Spectroscopic subsystems in nearby wide binaries

    CERN Document Server

    Tokovinin, Andrei

    2015-01-01

    Radial velocity (RV) monitoring of solar-type visual binaries has been conducted at the CTIO/SMARTS 1.5-m telescope to study short-period systems. Data reduction is described, mean and individual RVs of 163 observed objects are given. New spectroscopic binaries are discovered or suspected in 17 objects, for some of them orbital periods could be determined. Subsystems are efficiently detected even in a single observation by double lines and/or by the RV difference between the components of visual binaries. The potential of this detection technique is quantified by simulation and used for statistical assessment of 96 wide binaries within 67pc. It is found that 43 binaries contain at least one subsystem and the occurrence of subsystems is equally probable in either primary or secondary components. The frequency of subsystems and their periods match the simple prescription proposed by the author (2014, AJ, 147, 87). The remaining 53 simple wide binaries with a median projected separation of 1300AU have the distri...

  4. Expression, high-pressure refolding, purification, crystallization and preliminary X-ray analysis of a novel single-strand-specific 3'-5' exonuclease PhoExo I from Pyrococcus horikoshii OT3.

    Science.gov (United States)

    Miyazono, Ken-ichi; Tsutsumi, Kanae; Ishino, Yoshizumi; Tanokura, Masaru

    2014-08-01

    PhoExo I is a single-strand-specific 3'-5' exonuclease from Pyrococcus horikoshii OT3 and is thought to be involved in a Thermococcales-specific DNA-repair pathway. The recombinant PhoExo I protein was produced as inclusion bodies in Escherichia coli cells. Solubilization of the inclusion bodies was performed by the high-pressure refolding method and highly purified protein was subjected to crystallization by the sitting-drop vapour-diffusion method at 20°C. A crystal of PhoExo I was obtained in a reservoir solution consisting of 0.1 M Tris-HCl pH 8.9, 27% PEG 6000 and diffracted X-rays to 1.52 Å resolution. The crystal of PhoExo I belonged to space group H32, with unit-cell parameters a = b = 112.07, c = 202.28 Å. The crystal contained two PhoExo I molecules in the asymmetric unit. PMID:25084386

  5. Design and Implementation of BDB, the Binary Star Database

    Science.gov (United States)

    Kaygorodov, P.; Kovaleva, D.; Malkov, O.

    2013-02-01

    The Binary star DataBase (BDB, http://bdb.inasan.ru) is created to provide liasons between binary star catalogue data of various origin. Information on different observational types of binaries is obtained from heterogeneous sources of data - astronomical catalogues and surveys. The database allows a variety of query options useful for selected stars investigation purposes, for binary observations planning, and for construction and examination of binary datasets with certain characteristics.

  6. Enhancement of exo-polysaccharide production and antioxidant activity in submerged cultures of Inonotus obliquus by lignocellulose decomposition.

    Science.gov (United States)

    Chen, Hui; Yan, Mingchao; Zhu, Jinwei; Xu, Xiangqun

    2011-02-01

    We reported that lignocellulose decomposition can be used to facilitate the production of bioactive polysaccharides from submerged culture of Inonotus obliquus. Exo-polysaccharide (EPS) production and antioxidant activity by Inonotus obliquus was enhanced by employing lignocellulose decomposition in a corn straw-containing submerged fermentation. A significant increase in the EPS production and hydroxyl radical scavenging activity from 1.09 ± 0.01 g/l and 72.3 ± 1.9% in a basal medium to 1.38 ± 0.02 g/l and 82.7 ± 0.5% in a corn straw-containing medium was obtained. A synchronized effect between lignocellulose decomposition and malondialdehyde presenting hydroxyl radical concentration in the fermentation broth was identified. The adding of thiourea, a hydroxyl radical-scavenging reagent, suppressed malondialdehyde generation and lowered the lignocellulose decomposition rate. Correspondingly, the EPS production and hydroxyl radical scavenging activity decreased to 1.26 g/l and 74%. The EPS obtained from the corn straw-containing medium also presented the strongest superoxide radical scavenging activity. The monosaccharide components of the EPS from the corn straw-containing medium are rhamnose, arabinose, xylose, mannose, glucose, and galactose with molar proportions at 3.0, 3.0, 0.9, 46.6, 11.4, and 35.1%, respectively, which are largely different from the molar proportions of the EPS from the basal medium. PMID:20628784

  7. Tissue Responses to Stent Grafts with Endo-Exo-Skeleton for Saccular Abdominal Aortic Aneurysms in a Canine Model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Il Young; Chung, Jin Wook; Kim, Hyo Cheol [Dept. of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Clinical Research Institute, Seoul (Korea, Republic of); Choi, Young Ho; So Young Ho [Dept. of Radiology, Seoul National University Boramae Hospital, Seoul (Korea, Republic of); Kim, Hyun Beom [Dept. of Radiology, National Cancer Center, Goyang (Korea, Republic of); Min, Seung Kee [Dept. of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Jae Hyung [Dept. of Radiology, Gachon University Gil Medical Center, Incheon (Korea, Republic of)

    2014-10-15

    We evaluated the effect of close contact between the stent and the graft on the induction of endothelial covering on the stent graft placed over an aneurysm. Saccular abdominal aortic aneurysms were made with Dacron patch in eight dogs. The stent graft consisted of an inner stent, a expanded polytetrafluoroethylene graft, and an outer stent. After sacrificing the animals, the aortas with an embedded stent graft were excised. The aortas were inspected grossly and evaluated microscopically. The animals were sacrificed at two (n = 3), six (n = 3), and eight months (n = 2) after endovascular repair. In two dogs, the aortic lumen was occluded at two months after the placement. On gross inspection of specimens from the other six dogs with a patent aortic lumen, stent grafts placed over the normal aortic wall were covered by glossy white neointima, whereas, stent grafts placed over the aneurysmal aortic wall were covered by brownish neointima. On microscopic inspection, stent grafts placed over the normal aortic wall were covered by thin neointima (0.27 ± 0.05 mm, mean ± standard deviation) with an endothelial layer, and stent grafts placed over the aneurysmal aortic wall were covered by thick neointima (0.62 ± 0.17 mm) without any endothelial lining. Transgraft cell migration at the normal aortic wall was more active than that at the aneurysmal aortic wall. Close contact between the stent and the graft, which was achieved with stent grafts with endo-exo-skeleton, could not enhance endothelial covering on the stent graft placed over the aneurysms.

  8. Tissue Responses to Stent Grafts with Endo-Exo-Skeleton for Saccular Abdominal Aortic Aneurysms in a Canine Model

    International Nuclear Information System (INIS)

    We evaluated the effect of close contact between the stent and the graft on the induction of endothelial covering on the stent graft placed over an aneurysm. Saccular abdominal aortic aneurysms were made with Dacron patch in eight dogs. The stent graft consisted of an inner stent, a expanded polytetrafluoroethylene graft, and an outer stent. After sacrificing the animals, the aortas with an embedded stent graft were excised. The aortas were inspected grossly and evaluated microscopically. The animals were sacrificed at two (n = 3), six (n = 3), and eight months (n = 2) after endovascular repair. In two dogs, the aortic lumen was occluded at two months after the placement. On gross inspection of specimens from the other six dogs with a patent aortic lumen, stent grafts placed over the normal aortic wall were covered by glossy white neointima, whereas, stent grafts placed over the aneurysmal aortic wall were covered by brownish neointima. On microscopic inspection, stent grafts placed over the normal aortic wall were covered by thin neointima (0.27 ± 0.05 mm, mean ± standard deviation) with an endothelial layer, and stent grafts placed over the aneurysmal aortic wall were covered by thick neointima (0.62 ± 0.17 mm) without any endothelial lining. Transgraft cell migration at the normal aortic wall was more active than that at the aneurysmal aortic wall. Close contact between the stent and the graft, which was achieved with stent grafts with endo-exo-skeleton, could not enhance endothelial covering on the stent graft placed over the aneurysms.

  9. The yeast Wickerhamomyces anomalus AS1 secretes a multifunctional exo-β-1,3-glucanase with implications for winemaking.

    Science.gov (United States)

    Schwentke, Johannes; Sabel, Andrea; Petri, Anna; König, Helmut; Claus, Harald

    2014-09-01

    A multifunctional exo-β-1,3-glucanase (WaExg2) was purified from the culture supernatant of the yeast Wickerhamomyces anomalus AS1. The enzyme was identified by mass spectroscopic analysis of tryptic peptide fragments and the encoding gene WaEXG2 was sequenced. The latter codes for a protein of 427 amino acids, beginning with a probable signal peptide (17 aa) for secretion. The mature protein has a molecular mass of 47 456 Da with a calculated pI of 4.84. The somewhat higher mass of the protein in SDS-PAGE might be due to bound carbohydrates. Presumptive disulphide bridges confer a high compactness to the molecule. This explains the apparent smaller molecular mass (35 kDa) of the native enzyme determined by electrophoresis, whereas the unfolded form is consistent with the theoretical mass. Enzymatic hydrolysis of selected glycosides and glycans by WaExg2 was proved by TLC analysis of cleavage products. Glucose was detected as the sole hydrolysis product from laminarin, underlining that the enzyme acts as an exoglucanase. In addition, the enzyme efficiently hydrolysed small β-linked glycosides (arbutin, esculin, polydatin, salicin) and disaccharides (cellobiose, gentiobiose). WaExg2 was active under typical wine-related conditions, such as low pH (3.5-4.0), high sugar concentrations (up to 20% w/v), high ethanol concentrations (10-15% v/v), presence of sulphites (up to 2 mm) and various cations. Therefore, the characterized enzyme might have multiple uses in winemaking, to increase concentrations of sensory and bioactive compounds by splitting glycosylated precursors or to reduce viscosity by hydrolysis of glycan slimes. PMID:25044257

  10. Exploring the Birth of Binary Stars

    Science.gov (United States)

    Kohler, Susanna

    2016-08-01

    More than half of all stars are thought to be in binary or multiple star systems. But how do these systems form? The misaligned spins of some binary protostars might provide a clue.Two Formation ModelsIts hard to tell how multiple-star systems form, since these systems are difficult to observe in their early stages. But based on numerical simulations, there are two proposed models for the formation of stellar binaries:Turbulent fragmentationTurbulence within a single core leads to multiple dense clumps. These clumps independently collapse to form stars that orbit each other.Disk fragmentationGravitational instabilities in a massive accretion disk cause the formation of a smaller, secondary disk within the first, resulting in two stars that orbit each other.Log column density for one of the authors simulated binary systems, just after the formation of two protostars. Diamonds indicate the protostar positions. [Adapted from Offner et al. 2016]Outflows as CluesHow can we differentiate between these formation mechanisms? Led by Stella Offner (University of Massachusetts), a team of scientists has suggested that the key isto examine the alignment of the stars protostellar outflows jets that are often emitted from the poles of young, newly forming stars.Naively, wed expect that disk fragmentation would produce binary stars with common angular momentum. As the stars spins would be aligned, they would therefore also launch protostellar jets that were aligned with each other. Turbulent fragmentation, on the other hand, would cause the stars to have independent angular momentum. This would lead to randomly oriented spins, so the protostellar jets would be misaligned.Snapshots from the authors simulations. Left panel of each pair: column density; green arrows giveprotostellar spin directions. Right panel: synthetic observations produced from the simulations; cyan arrows giveprotostellar outflow directions. [Offner et al. 2016]Simulations of FragmentationIn order to better

  11. Designing of the specific DNA primers for detection of the exoA, oprL and algD pathogenicity genes for rapid diagnosis of Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Mohammad Najafimosleh

    2013-11-01

    Full Text Available Background: The aim of this study was compared the efficacy of  the designed primers and already published primers for detection of the exoA, oprL and algD genes by PCR assay  for finding a rapid, accurate and highly sensitive and specific procedure to detect the Pseudomonas aeruginosa in the serious and fatal infections such as cystic fibrosis disease, burned individual.Methods: A total of 150 clinical specimens were inoculated in to routine and selective culture media for Pseudomonas aeruginosa isolation. Specific primers were designed by bioinformatics analysis for detection of the virulence genes exoA, oprL and algD. The available sequences of these three genes were obtained from NCBI and multiple alignments were performed to find the conserved sequences of each gene for primer designing. Both multiple alignment and primer designing steps were carried out by AlleleID software, version 7.0.Results: Microbiological culture methods were showed that 70 Pseudomonas aeruginosa strains isolated from the 150 clinical specimens. PCR assay performed by using the designed primers shown 68, 70 and 69 positive results from 70 direct specimens for exoA, oprL and algD respectively that shown 97.2%, 100% and 98.6% sensitivity for above genes. PCR assay performed by using the already published primers shown 57, 49 and 28 positive results for above genes respectively that shown 81.5%, 70% and 40% sensitivity.Conclusion: The present study shows that by using the high specific primers for detection of the mentioned genes of the Pseudomonas aeruginosa. The conventional PCR assay detected the early colonization of the organism in Cystic Fibrosis patients with more sensitivity and specificity before several mounts to obtain positive culture. Indeed PCR assay with high specific primers has more sensitivity and specificity as a rapid and accurate diagnosis of the organism in other deadly infections by using the direct clinical specimens.

  12. Linking gene regulation and the exo-metabolome: A comparative transcriptomics approach to identify genes that impact on the production of volatile aroma compounds in yeast

    Directory of Open Access Journals (Sweden)

    Bauer Florian F

    2008-11-01

    Full Text Available Abstract Background 'Omics' tools provide novel opportunities for system-wide analysis of complex cellular functions. Secondary metabolism is an example of a complex network of biochemical pathways, which, although well mapped from a biochemical point of view, is not well understood with regards to its physiological roles and genetic and biochemical regulation. Many of the metabolites produced by this network such as higher alcohols and esters are significant aroma impact compounds in fermentation products, and different yeast strains are known to produce highly divergent aroma profiles. Here, we investigated whether we can predict the impact of specific genes of known or unknown function on this metabolic network by combining whole transcriptome and partial exo-metabolome analysis. Results For this purpose, the gene expression levels of five different industrial wine yeast strains that produce divergent aroma profiles were established at three different time points of alcoholic fermentation in synthetic wine must. A matrix of gene expression data was generated and integrated with the concentrations of volatile aroma compounds measured at the same time points. This relatively unbiased approach to the study of volatile aroma compounds enabled us to identify candidate genes for aroma profile modification. Five of these genes, namely YMR210W, BAT1, AAD10, AAD14 and ACS1 were selected for overexpression in commercial wine yeast, VIN13. Analysis of the data show a statistically significant correlation between the changes in the exo-metabome of the overexpressing strains and the changes that were predicted based on the unbiased alignment of transcriptomic and exo-metabolomic data. Conclusion The data suggest that a comparative transcriptomics and metabolomics approach can be used to identify the metabolic impacts of the expression of individual genes in complex systems, and the amenability of transcriptomic data to direct applications of

  13. New spectroscopic binary companions of giant stars and updated metallicity distribution for binary systems

    CERN Document Server

    Bluhm, P; Vanzi, L; Soto, M G; Vos, J; Wittenmyer, R A; Olivares, F; Drass, H; Mennickent, R E; Vuckovic, M; Rojo, P; Melo, C H F

    2016-01-01

    We report the discovery of 24 spectroscopic binary companions to giant stars. We fully constrain the orbital solution for 6 of these systems. We cannot unambiguously derive the orbital elements for the remaining stars because the phase coverage is incomplete. Of these stars, 6 present radial velocity trends that are compatible with long-period brown dwarf companions.The orbital solutions of the 24 binary systems indicate that these giant binary systems have a wide range in orbital periods, eccentricities, and companion masses. For the binaries with restricted orbital solutions, we find a range of orbital periods of between $\\sim$ 97-1600 days and eccentricities of between $\\sim$ 0.1-0.4. In addition, we studied the metallicity distribution of single and binary giant stars. We computed the metallicity of a total of 395 evolved stars, 59 of wich are in binary systems. We find a flat distribution for these binary stars and therefore conclude that stellar binary systems, and potentially brown dwarfs, have a diffe...

  14. Towards the field binary population: Influence of orbital decay on close binaries

    CERN Document Server

    Korntreff, Christina; Pfalzner, Susanne

    2012-01-01

    Surveys of the binary populations in the solar neighbourhood have shown that the periods of G- and M-type stars are log-normally distributed. However, observations of young binary populations suggest a log-uniform distribution. Clearly some process(es) change the period distribution over time. Most stars form in star clusters, in which two important dynamical processes occur: i) gas-induced orbital decay of embedded binary systems and ii) destruction of soft binaries in three-body interactions. The emphasis here is on orbital decay which has been largely neglected so far. Using a combination of Monte-Carlo and dynamical nbody modelling it is demonstrated here that the cluster dynamics destroys the number of wide binaries, but leaves short-period binaries basically undisturbed even for a initially log-uniform distribution. By contrast orbital decay significantly reduces the number and changes the properties of short-period binaries, but leaves wide binaries largely uneffected. Until now it was unclear whether ...

  15. Gravitational wave background from binary systems

    International Nuclear Information System (INIS)

    Basic aspects of the background of gravitational waves and its mathematical characterization are reviewed. The spectral energy density parameter Ω(f), commonly used as a quantifier of the background, is derived for an ensemble of many identical sources emitting at different times and locations. For such an ensemble, Ω(f) is generalized to account for the duration of the signals and of the observation, so that one can distinguish the resolvable and unresolvable parts of the background. The unresolvable part, often called confusion noise or stochastic background, is made by signals that cannot be either individually identified or subtracted out of the data. To account for the resolvability of the background, the overlap function is introduced. This function is a generalization of the duty cycle, which has been commonly used in the literature, in some cases leading to incorrect results. The spectra produced by binary systems (stellar binaries and massive black hole binaries) are presented over the frequencies of all existing and planned detectors. A semi-analytical formula for Ω(f) is derived in the case of stellar binaries (containing white dwarfs, neutron stars or stellar-mass black holes). Besides a realistic expectation of the level of background, upper and lower limits are given, to account for the uncertainties in some astrophysical parameters such as binary coalescence rates. One interesting result concerns all current and planned ground-based detectors (including the Einstein Telescope). In their frequency range, the background of binaries is resolvable and only sporadically present. In other words, there is no stochastic background of binaries for ground-based detectors.

  16. Birth of Massive Black Hole Binaries

    Energy Technology Data Exchange (ETDEWEB)

    Colpi, M.; /Milan Bicocca U.; Dotti, M.; /Insubria U., Como; Mayer, L.; /Zurich, ETH; Kazantzidis, S.; /KIPAC, Menlo Park

    2007-11-19

    If massive black holes (BHs) are ubiquitous in galaxies and galaxies experience multiple mergers during their cosmic assembly, then BH binaries should be common albeit temporary features of most galactic bulges. Observationally, the paucity of active BH pairs points toward binary lifetimes far shorter than the Hubble time, indicating rapid inspiral of the BHs down to the domain where gravitational waves lead to their coalescence. Here, we review a series of studies on the dynamics of massive BHs in gas-rich galaxy mergers that underscore the vital role played by a cool, gaseous component in promoting the rapid formation of the BH binary. The BH binary is found to reside at the center of a massive self-gravitating nuclear disc resulting from the collision of the two gaseous discs present in the mother galaxies. Hardening by gravitational torques against gas in this grand disc is found to continue down to sub-parsec scales. The eccentricity decreases with time to zero and when the binary is circular, accretion sets in around the two BHs. When this occurs, each BH is endowed with it own small-size ({approx}< 0.01 pc) accretion disc comprising a few percent of the BH mass. Double AGN activity is expected to occur on an estimated timescale of {approx}< 1 Myr. The double nuclear point-like sources that may appear have typical separation of {approx}< 10 pc, and are likely to be embedded in the still ongoing starburst. We note that a potential threat of binary stalling, in a gaseous environment, may come from radiation and/or mechanical energy injections by the BHs. Only short-lived or sub-Eddington accretion episodes can guarantee the persistence of a dense cool gas structure around the binary necessary for continuing BH inspiral.

  17. CARMENES: Calar Alto high-Resolution search for M dwarfs with Exo-earths with a Near-infrared Echelle Spectrograph

    CERN Document Server

    Quirrenbach, A; Mandel, H; Caballero, J A; Ribas, I; Reiners, A; Mundt, R; Abril, M; Afonso, C; Bean, J L; Bejar, V J S; Becerril, S; Boehm, A; Cardenas, C; Claret, A; Colome, J; Costillo, L P; Dreizler, S; Fernandez, M; Francisco, X; Garrido, R; Hernandez, J I Gonzalez; Guenther, E W; Gutierrez-Soto, J; Joergens, V; Hatzes, A P; Henning, T; Herrero, E; Kurster, M; Laun, W; Lenzen, R; Mall, U; Martin, E L; Martin-Ruiz, S; Montes, D; Morales, J C; Munoz, R Morales; Moya, A; Naranjo, V; Rabaza, O; Ramon, A; Rebolo, R; Reffert, S; Rodler, F; Rodriguez, E; Trinidad, A Rodriguez; Rohloff, R -R; Carrasco, M A Sanchez; Schmidt, C; Seifert, W; Setiawan, J; Stahl, O; Suarez, J C; Wiedemann, G; del Burgo, C; Galadi, D; Sanchez-Blanco, E; Xu, W

    2009-01-01

    CARMENES, Calar Alto high-Resolution search for M dwarfs with Exo-earths with a Near-infrared Echelle Spectrograph, is a study for a next-generation instrument for the 3.5m Calar Alto Telescope to be designed, built, integrated, and operated by a consortium of nine German and Spanish institutions. Our main objective is finding habitable exoplanets around M dwarfs, which will be achieved by radial velocity measurements on the m/s level in the near-infrared, where low-mass stars emit the bulk of their radiation.

  18. Task I: Dark Matter Search Experiments with Cryogenic Detectors: CDMS-I and CDMS-II Task II: Experimental Study of Neutrino Properties: EXO and KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, Blas [Stanford Univ., CA (United States); Gratta, Giorgio [Stanford Univ., CA (United States)

    2013-08-30

    design and optimize the analysis. Neutrino Physics – In the period of performance the neutrino group successfully completed the construction of EXO-200 and commissioned the detector. Science data taking started on Jun 1, 2011. With the discovery of the 2-neutrino double-beta decay in 136-Xe and the first measurement of the 0-neutrino mode resulting in the most stringent limit of Majorana masses, our group continues to be a leading innovator in the field of neutrino physics which is central to DOE-HEP Intensity Frontier program. The phenomenon of neutrino oscillations, in part elucidated by our earlier efforts with the Palo Verde and KamLAND experiments, provides the crucial information that neutrino masses are non-zero and, yet, it contains no information on the value of the neutrino mass scale. In recent times our group has therefore shifted its focus to a high sensitivity 0-neutrino double beta decay program, EXO. The 0-neutrino double beta decay provides the best chance of extending the sensitivity to the neutrino mass scale below 10 meV but, maybe more importantly, it tests the nature of the neutrino wave function, providing the most sensitive probe for Majorana particles and lepton number violation. The EXO program, formulated by our group several years ago, plans to use up to tonnes of the isotope 136-Xe to study the 0-neutrino double beta decay mode. The EXO-200 detector is the first step in this program and it represents the only large US-led and based experiment taking data. The EXO-200 isotope enrichment program broke new grounds for the enterprise of double beta decay. The detector design and material selection program paid off, resulting in a background that is among the very best in the field. The “first light" of EXO-200 was very exciting with the discovery -in the first month of data- of the rarest 2-neutrino double beta decay mode ever observed. The lower limit on the 0-neutrino double beta decay half-life, published in Phys. Rev. Lett. and based on

  19. Secondary deuterium kinetic isotope effects and the intervention of nonclassical ions in the solvolysis of exo-norborn-2-yl bromobenzene-p-sulfonate

    International Nuclear Information System (INIS)

    Deuterio- and 1,2-dideuterio-exo-norborn-2-yl bromobenzene-p-sulfonates have been prepared, and the deuterium kinetic isotope effects have been measured in 80% aqueous ethanol (k11/k/sup D/ = 1.081, 25.50C, and 1.192, 25.40C, respectively) and buffered acetic acid (1.051 and 1.173, respectively, 29.40C). These results are in accordance with a mechanism involving bridging at the transition state for ionization which leads to the nonclassical norbornyl cation. The results are incompatible with a mechanism involving direct ionization to interconverting classical cations

  20. Sodium-cation conductivity in the Na4-xP2-4ExO7 (E = Cr, Mo, W) systems

    International Nuclear Information System (INIS)

    Electrical conductivity of solid solutions on the basis of the sodium pyrophosphate in the Na4-xP2-4ExO7 (E = Cr, Mo, W) systems is studied. The electrolytes in the system with E = Cr have the maximum sodium-cation conductivity in the area of existence of the Na4P2O7 (1.35 x 10-1 Cm cm-1 at 700 Deg C) high temperature form. Effect of dimension and electronegativity of the E modifying elements on electrical properties of solid solutions is considered

  1. Effect of an exo-polysaccharide from the culture broth of Hericium erinaceus on enhancement of growth and differentiation of rat adrenal nerve cells

    OpenAIRE

    Park, Young Shik; Lee, Hyun Soo; Won, Moo Ho; Lee, Jin Ha; Lee, Shin Young; Lee, Hyeon Yong

    2002-01-01

    It was found that an exo-biopolymer (M.W. 1,000,000, molar ratio of 1.5:1.7:1.2:0.6:0.9, glucose:galactose:xylose:mannose:fructose, purity 99%) purified from the liquid culture broth of Hericium erinaceus mycelium enhanced the growth of rat adrenal nerve cells. The polymer also improved the extension of the neurites of PC12 cell. Its efficacy was found to be higher than those from known nerve growth factors such as Nerve Growth Factor (NGF) and Brain-Derived Nerve Factor (BDNF). The effect of...

  2. Patient Satisfaction After Femoral Arterial Access Site Closure Using the ExoSeal® Vascular Closure Device Compared to Manual Compression: A Prospective Intra-individual Comparative Study

    International Nuclear Information System (INIS)

    PurposeTo intra-individually compare discomfort levels and patient satisfaction after arterial access closure using the ExoSeal® vascular closure device (VCD) and manual compression (MC) in a prospective study design.MethodsPatients undergoing two planned interventions from 07/2013 to 09/2014 could participate in the study. Access closure was performed with an ExoSeal®-VCD in one and MC in the other intervention. Patients were clinically and sonographically examined and were given questionnaires 1 day after intervention [groin- and back-pain during bedrest (100-point visual analog scale; 0: no pain); comfortability of bedrest (10-point Likert scale, 1: comfortable), satisfaction with closure (10-point Likert scale, 1: very satisfied)]. Results were analyzed in a cross-over design.Results48 patients (29 male, median age 62.5 (32–88) years) were included. An ExoSeal®-VCD was used first in 25 cases. As four of these subsequently refused MC as second intervention, data from 44 patients could be analyzed. All closures were technically successful (successful device deployment) without major complications. Groin- and back-pain after VCD-use/MC was 0 (0–15) vs. 10 (0–80) and 0 (0–75) vs. 25 (0–90), respectively (p < 0.0001). Bedrest after VCD-use was more comfortable than after MC [1 (range 1–7) vs. 6 (2–10); p < 0.0001]. Satisfaction with the closure procedure and with the intervention in general was higher after VCD-use compared to MC [1 (1–3) vs. 5 (2–10) and 1 (1–2) vs. 2 (1–4), respectively; p < 0.0001].ConclusionIntra-individual comparison showed pain levels and discomfort to be significantly lower after ExoSeal® use compared to MC. VCD closure was associated with higher satisfaction both with the closure itself and with the intervention in general

  3. Comparison of plasma clearance of exogenous creatinine, exo-iohexol, and endo-iohexol over a range of glomerular filtration rates expected in cats.

    Science.gov (United States)

    van Hoek, Ingrid M; Lefebvre, Hervé P; Paepe, Dominique; Croubels, Siska; Biourge, Vincent; Daminet, Sylvie

    2009-12-01

    The study investigated plasma clearance of exogenous creatinine (PECCT), exo-iohexol (PexICT) and endo-iohexol (PenICT) in six healthy cats, four cats with chronic kidney disease (CKD) and six hyperthyroid (HT) cats to assess potential differences in glomerular filtration rate (GFR) measurement over a wide range of GFR values. The PECCT, PexICT and PenICT were performed in a combined protocol. There was a significant difference between PexICT and PenICT and PECCT in healthy cats. Differences between clearance techniques are suggested to be correlated to range in GFRs and should be taken into account when GFR is measured. PMID:19679501

  4. Massive gaseous discs around SMBH binaries: Binary decay and tidal disruptions

    Directory of Open Access Journals (Sweden)

    Brem P.

    2012-12-01

    Full Text Available We investigate the evolution of black hole binaries embedded within geometrically thin gas discs. Our results imply that such discs can produce black hole mergers for relatively low-mass binaries, and that a significant population of eccentric binaries might exist at separations of a few 0.01 pc. These binaries may be detectable due to the time-variable accretion on to the black holes. If the disc fragments, then the newly-born stars will continue driving the binary to its coalescence, although at a slower rate. Interestingly, our preliminary analysis shows that these stars will be disrupted at a rate of ∼10−4–2 · 10−5 events per year per system.

  5. Serial binary interval ratios improve rhythm reproduction

    Directory of Open Access Journals (Sweden)

    XiangWu

    2013-08-01

    Full Text Available Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8, non-binary integer (1:3:5:6, and non-integer (1:2.3:5.3:6.4 ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

  6. Urey Prize Lecture: Binary Minor Planets

    Science.gov (United States)

    Margot, J. L.

    2004-11-01

    The discovery of binary systems in the near-Earth, main belt, and Kuiper belt populations provides an abundance of new data that expand our knowledge of the physics and chemistry of the solar system. Binary minor planets form as a result of collisional, tidal, and capture processes that are important to study as they play major roles in the formation and evolution of planetary systems. The frequency of occurrence of such processes directly reflects the dynamical environment in the various populations. Observations of binaries provide a powerful way to measure the bulk properties of small bodies, which in turn lead to inferences about their composition and internal structure. These data may offer a rare glimpse of what physical and chemical conditions prevailed when protoplanets formed, and what subsequent evolution took place. In the case of the Kuiper Belt, the study of a handful of binaries forces us to rethink how dense and how bright these bodies are, and to significantly revise our current mass estimates for the entire population. The number of known binary minor planets has increased dramatically over the past few years, with roughly ten new discoveries each year. I will attempt to summarize recent developments, with examples drawn from my observations with the Hubble, Palomar, Keck, Arecibo and Goldstone telescopes.

  7. Orbital eccentricities in primordial black holes binaries

    CERN Document Server

    Cholis, Ilias; Ali-Haïmoud, Yacine; Bird, Simeon; Kamionkowski, Marc; Muñoz, Julian B; Raccanelli, Alvise

    2016-01-01

    It was recently suggested that the merger of $\\sim30\\,M_\\odot$ primordial black holes (PBHs) may provide a significant number of events in gravitational-wave observatories over the next decade, if they make up an appreciable fraction of the dark matter. Here we show that measurement of the eccentricities of the inspiralling binary black holes can be used to distinguish these binaries from those produced by more traditional astrophysical mechanisms. These PBH binaries are formed on highly eccentric orbits and can then merge on timescales that in some cases are years or less, retaining some eccentricity in the last seconds before the merger. This is to be contrasted with massive-stellar-binary, globular-cluster, or other astrophysical origins for binary black holes (BBHs) in which the orbits have very effectively circularized by the time the BBH enters the observable LIGO window. Here we discuss the features of the gravitational-wave signals that indicate this eccentricity and forecast the sensitivity of LIGO a...

  8. Spherical hashing: binary code embedding with hyperspheres.

    Science.gov (United States)

    Heo, Jae-Pil; Lee, Youngwoon; He, Junfeng; Chang, Shih-Fu; Yoon, Sung-Eui

    2015-11-01

    Many binary code embedding schemes have been actively studied recently, since they can provide efficient similarity search, and compact data representations suitable for handling large scale image databases. Existing binary code embedding techniques encode high-dimensional data by using hyperplane-based hashing functions. In this paper we propose a novel hypersphere-based hashing function, spherical hashing, to map more spatially coherent data points into a binary code compared to hyperplane-based hashing functions. We also propose a new binary code distance function, spherical Hamming distance, tailored for our hypersphere-based binary coding scheme, and design an efficient iterative optimization process to achieve both balanced partitioning for each hash function and independence between hashing functions. Furthermore, we generalize spherical hashing to support various similarity measures defined by kernel functions. Our extensive experiments show that our spherical hashing technique significantly outperforms state-of-the-art techniques based on hyperplanes across various benchmarks with sizes ranging from one to 75 million of GIST, BoW and VLAD descriptors. The performance gains are consistent and large, up to 100 percent improvements over the second best method among tested methods. These results confirm the unique merits of using hyperspheres to encode proximity regions in high-dimensional spaces. Finally, our method is intuitive and easy to implement. PMID:26440269

  9. An interferometric view of binary stars

    CERN Document Server

    Boffin, Henri M J

    2016-01-01

    The study of binary stars is critical to apprehend many of the most interesting classes of stars. Moreover, quite often, the study of stars in binary systems is our only mean to constrain stellar properties, such as masses and radii. Unfortunately, a great fraction of the most interesting binaries are so compact that they can only be apprehended by high-resolution techniques, mostly by interferometry. I present some results highlighting the use of interferometry in the study of binary stars, from finding companions and deriving orbits, determining the mass and radius of stars, to studying mass transfer in symbiotic stars, and tackling luminous blue variables. In particular, I show how interferometric studies using the PIONIER instrument have allowed us to confirm a dichotomy within symbiotic stars, obtain masses of stars with a precision better than 1%, and help us find a new Eta Carinae-like system. I will also illustrate the benefits for the study of binary stars one would get from upgrading the VLT Interfe...

  10. Planet Scattering Around Binaries: Ejections, Not Collisions

    Science.gov (United States)

    Smullen, Rachel A.; Kratter, Kaitlin M.; Shannon, Andrew

    2016-06-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary star and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically effects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Systems similar to the only observed multi-planet circumbinary system, Kepler-47, can arise from much more tightly packed, unstable systems. Only extreme initial conditions introduce differences in the final planet populations. Thus, we suggest that any intrinsic differences in the populations are imprinted by formation.

  11. Investigating Dark Energy with Black Hole Binaries

    International Nuclear Information System (INIS)

    The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accrete dark energy. The accretion induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state w[z] of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. This talk describes how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy.

  12. INTEGRAL & RXTE View of Gamma-ray Binaries

    OpenAIRE

    Jian LI; Torres, Diego F.; Zhang, Shu; WANG, JIANMIN

    2013-01-01

    Gamma-ray binaries are X-ray binaries with gamma-ray emissions. Their multi-wavelength emissions range from radio, optical, X-ray and to very high energy (TeV). X-ray emissions are crucial to understand the nature of gamma-ray binaries. INTEGRAL and RXTE have covered and monitored most of the gamma-ray binaries in hard and soft X-rays. Here we report the results of several gamma-ray binaries and possible gamma-ray binaries from INTEGRAL and RXTE.

  13. The Circulation Pattern in Simulated Contact Binaries

    Science.gov (United States)

    Motl, Patrick M.; Frank, J.; Tohline, J. E.

    2006-06-01

    We present a three-dimensional hydrodynamical simulation of an initially symmetric (equal mass) binary where both components are marginally in contact. The simulation evolves the binary through approximately 150 orbital periods and within the first 20 orbits, a global velocity field is established that carries material between both components. In the equatorial plane, the flow is along a figure eight pattern with streams of material sliding past one another in the neighborhood of the inner Lagrange point. For our chosen equation of state, mass transfer is ultimately unstable in this binary though the growth time is long compared to the orbital period. We are therefore able to observe that the circulation pattern, once established, is quite close to steady state. We explore the role that similar steady state flows may play in real contact systems.

  14. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    International Nuclear Information System (INIS)

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 105-106 years.

  15. Gravitational waves from spinning eccentric binaries

    CERN Document Server

    Csizmadia, Péter; Rácz, István; Vasúth, Mátyás

    2012-01-01

    This paper is to introduce a new software called CBwaves which provides a fast and accurate computational tool to determine the gravitational waveforms yielded by generic spinning binaries of neutron stars and/or black holes on eccentric orbits. This is done within the post-Newtonian (PN) framework by integrating the equations of motion and the spin precession equations while the radiation field is determined by a simultaneous evaluation of the analytic waveforms. In applying CBwaves various physically interesting scenarios have been investigated. In particular, we have studied the appropriateness of the adiabatic approximation, and justified that the energy balance relation is indeed insensitive to the specific form of the applied radiation reaction term. By studying eccentric binary systems it is demonstrated that circular template banks are very ineffective in identifying binaries even if they possess tiny residual orbital eccentricity. In addition, by investigating the validity of the energy balance relat...

  16. Binary Particle Model of Weak Interactions

    CERN Document Server

    Ndili, F N

    2011-01-01

    We introduce the new concept of binary particle as the basic matter unit that participates in weak interactions and not any one fermion singly. We state the quantum numbers of this binary particle, and show the concept leads us to a natural explanation of the standard model puzzle of the origin of flavor mixing and the CKM matrix. Certain other puzzles of the standard model such as the absence of flavor changing neutral currents (FCNC), are also explained naturally by the binary particle model. These puzzles are currently thought to be esoteric properties of electro weak interactions that have origins in physics beyond the standard model at some ultra high energy scales. We show that this is not necessarily the case.

  17. A binary spelling interface with random errors.

    Science.gov (United States)

    Perelmouter, J; Birbaumer, N

    2000-06-01

    An algorithm for design of a spelling interface based on a modified Huffman's algorithm is presented. This algorithm builds a full binary tree that allows to maximize an average probability to reach a leaf where a required character is located when a choice at each node is made with possible errors. A means to correct errors (a delete-function) and an optimization method to build this delete-function into the binary tree are also discussed. Such a spelling interface could be successfully applied to any menu-orientated alternative communication system when a user (typically, a patient with devastating neuromuscular handicap) is not able to express an intended single binary response, either through motor responses or by using of brain-computer interfaces, with an absolute reliability. PMID:10896195

  18. Hybrid Black-Hole Binary Initial Data

    Science.gov (United States)

    Mundim, Bruno C.; Kelly, Bernard J.; Nakano, Hiroyuki; Zlochower, Yosef; Campanelli, Manuela

    2010-01-01

    "Traditional black-hole binary puncture initial data is conformally flat. This unphysical assumption is coupled with a lack of radiation signature from the binary's past life. As a result, waveforms extracted from evolutions of this data display an abrupt jump. In Kelly et al. [Class. Quantum Grav. 27:114005 (2010)], a new binary black-hole initial data with radiation contents derived in the post-Newtonian (PN) calculations was adapted to puncture evolutions in numerical relativity. This data satisfies the constraint equations to the 2.5PN order, and contains a transverse-traceless "wavy" metric contribution, violating the standard assumption of conformal flatness. Although the evolution contained less spurious radiation, there were undesired features; the unphysical horizon mass loss and the large initial orbital eccentricity. Introducing a hybrid approach to the initial data evaluation, we significantly reduce these undesired features."

  19. Modeling Flows Around Merging Black Hole Binaries

    CERN Document Server

    van Meter, James R; Miller, M Coleman; Reynolds, Christopher S; Centrella, Joan M; Baker, John G; Boggs, William D; Kelly, Bernard J; McWilliams, Sean T

    2009-01-01

    Coalescing massive black hole binaries are produced by the mergers of galaxies. The final stages of the black hole coalescence produce strong gravitational radiation that can be detected by the space-borne LISA. In cases where the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a step towards solving this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We find qualitative differences in collision and outflow speeds, including a signature of the merger when the net angular momentum of the matter is low, between the results from single and binary black holes, and between nonrotating and rotating holes in binaries. If future magnetohydrodynamic results confirm ...

  20. Nonlinear Tides in Close Binary Systems

    CERN Document Server

    Weinberg, Nevin N; Quataert, Eliot; Burkart, Josh

    2011-01-01

    We study the excitation and damping of tides in close binary systems, accounting for the leading order nonlinear corrections to linear tidal theory. These nonlinear corrections include two distinct effects: three-mode nonlinear interactions and nonlinear excitation of modes by the time-varying gravitational potential of the companion. This paper presents the formalism for studying nonlinear tides and studies the nonlinear stability of the linear tidal flow. Although the formalism is applicable to binaries containing stars, planets, or compact objects, we focus on solar type stars with stellar or planetary companions. Our primary results include: (1) The linear tidal solution often used in studies of binary evolution is unstable over much of the parameter space in which it is employed. More specifically, resonantly excited gravity waves are unstable to parametric resonance for companion masses M' > 10-100 M_Earth at orbital periods P = 1-10 days. The nearly static equilibrium tide is, however, parametrically s...

  1. Gravitational wave background from binary systems

    CERN Document Server

    Rosado, Pablo A

    2011-01-01

    Basic aspects of the background of gravitational waves and its mathematical characterization are reviewed. The spectral energy density parameter $\\Omega(f)$, commonly used as a quantifier of the background, is derived for an ensemble of many identical sources emitting at different times and locations. For such an ensemble, $\\Omega(f)$ is generalized to account for the duration of the signals and of the observation, so that one can distinguish the resolvable and unresolvable parts of the background. The unresolvable part, often called confusion noise or stochastic background, is made by signals that cannot be either individually identified or subtracted out of the data. To account for the resolvability of the background, the overlap function is introduced. This function is a generalization of the duty cycle, which has been commonly used in the literature, in some cases leading to incorrect results. The spectra produced by binary systems (stellar binaries and massive black hole binaries) are presented over the ...

  2. Binary Code Disassembly for Reverse Engineering

    Directory of Open Access Journals (Sweden)

    Marius Popa

    2013-01-01

    Full Text Available The disassembly of binary file is used to restore the software application code in a readable and understandable format for humans. Further, the assembly code file can be used in reverse engineering processes to establish the logical flows of the computer program or its vulnerabilities in real-world running environment. The paper highlights the features of the binary executable files under the x86 architecture and portable format, presents issues of disassembly process of a machine code file and intermediate code, disassembly algorithms which can be applied to a correct and complete reconstruction of the source file written in assembly language, and techniques and tools used in binary code disassembly.

  3. Supermassive Black Hole Binaries as Galactic Blenders

    CERN Document Server

    Kandrup, H E; Terzic, B; Bohn, C L; Kandrup, Henry E.; Sideris, Ioannis V.; Terzic, Balsa; Bohn, Courtlandt L.

    2003-01-01

    This paper focuses on the dynamical implications of close supermassive black hole binaries both as an example of resonant phase mixing and as a potential explanation of inversions and other anomalous features observed in the luminosity profiles of some elliptical galaxies. The presence of a binary comprised of black holes executing nearly periodic orbits leads to the possibility of a broad resonant coupling between the black holes and various stars in the galaxy. This can result in efficient chaotic phase mixing and, in many cases, systematic increases in the energies of stars and their consequent transport towards larger radii. Allowing for the presence of a supermassive black hole binary with plausible parameter values near the center of a spherical, or nearly spherical, galaxy characterised initially by a Nuker density profile enables one to reproduce in considerable detail the central surface brightness distributions of such galaxies as NGC 3706.

  4. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    International Nuclear Information System (INIS)

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886

  5. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Kaltenegger, Lisa [MPIA, Koenigstuhl 17, D-69117 Heidelberg (Germany); Haghighipour, Nader, E-mail: kaltenegger@mpia.de [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States)

    2013-11-10

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886.

  6. A Quick Study of Science Return from Direct Imaging Exoplanet Missions: Detection and Characterization of Circumstellar Material with an AFTA or EXO-C/S CGI

    CERN Document Server

    Schneider, Glenn

    2014-01-01

    The capabilities of a high (~ 10^-9 resel^-1) contrast, narrow-field, coronagraphic instrument (CGI) on a space-based AFTA-C or probe-class EXO-C/S mission, conceived to study the diversity of exoplanets now known to exist into stellar habitable zones, are particularly and importantly germane to symbiotic studies of the systems of circumstellar (CS) material from which planets have emerged and interact with throughout their lifetimes. The small particle populations in "disks" of co-orbiting materials can trace the presence of planets through dynamical interactions that perturb the spatial distribution of the light-scattering debris, detectable at optical wavelengths and resolvable with an AFTA-C or EXO-S/C CGI. Herein we: (1) present the science case to study the formation, evolution, architectures, diversity, and properties of the material in the planet-hosting regions of nearby stars, (2) discuss how a CGI under current conception can uniquely inform and contribute to those investigations, (3) consider the ...

  7. Binary black holes' effects on electromagnetic fields.

    Science.gov (United States)

    Palenzuela, Carlos; Anderson, Matthew; Lehner, Luis; Liebling, Steven L; Neilsen, David

    2009-08-21

    In addition to producing gravitational waves, the dynamics of a binary black hole system could induce emission of electromagnetic radiation by affecting the behavior of plasmas and electromagnetic fields in their vicinity. We here study how the electromagnetic fields are affected by a pair of orbiting black holes through the merger. In particular, we show how the binary's dynamics induce a variability in possible electromagnetically induced emissions as well as a possible enhancement of electromagnetic fields during the late-merge and merger epochs. These time dependent features will likely leave their imprint in processes generating detectable emissions and can be exploited in the detection of electromagnetic counterparts of gravitational waves. PMID:19792706

  8. Spin supplementary conditions for spinning compact binaries

    CERN Document Server

    Mikóczi, Balázs

    2016-01-01

    We consider the different spin supplementary conditions (SSC) for a spinning compact binary with the leading-order spin-orbit (SO) interaction. The Lagrangian of the binary system can be constructed but it is acceleration-dependent in two cases of SSC. We rewrite the generalized Hamiltonian formalism proposed by Ostrogradsky and compute the conservative quantities and the dissipative part of relative motion during the gravitational radiation of each SSCs. We give the orbital elements and observed quantities of the SO dynamics, for instance the energy and the orbital angular momentum losses and waveforms and discuss their SSC dependence.

  9. Quasi periodic oscillations in black hole binaries

    CERN Document Server

    Motta, S E

    2016-01-01

    Fast time variability is the most prominent characteristic of accreting systems and the presence of quasi periodic oscillations (QPOs) is a constant in all accreting systems, from cataclysmic variables to AGNs, passing through black hole and neutron star X-ray binaries and through the enigmatic ultra-luminous X-ray sources. In this paper I will briefly review the current knowledge of QPOs in black hole X-ray binaries, mainly focussing on their observed properties, but also mentioning the most important models that have been proposed to explain the origin of QPOs over the last decades.

  10. Photometric constraints on binary asteroid dynamics

    Science.gov (United States)

    Scheirich, Peter

    2015-08-01

    To date, about 50 binary NEAs, 20 Mars-crossing and 80 small MB asteroids are known. We observe also a population of about 200 unbound asteroid systems (asteroid pairs). I will review the photometric observational data we have for the best observed cases and compare them with theories of binary and paired asteroids evolution.The observed characteristics of asteroid systems suggest their formation by rotational fission of parent rubble-pile asteroids after being spun up by the YORP effect. The angular momentum content of binary asteroids is close to critical. The orientations of satellite orbits of observed binary systems are non-random; the orbital poles concentrate near the obliquities of 0 and 180 degrees, i.e., near the YORP asymptotic states.Recently, a significant excess of retrograde satellite orbits was detected, which is not yet explained characteristic.An evolution of binary system depend heavily on the BYORP effect. If BYORP is contractive, the primary and secondary could end in a tidal-BYORP equilibrium. Observations of mutual events between binary components in at least four apparitions are needed for BYORP to be revealed by detecting a quadratic drift in mean anomaly of the satellite. I will show the observational evidence of single-synchronous binary asteroid with tidally locked satellite (175706 1996 FG3), i.e, with the quadratic drift equal to zero, and binary asteroid with contracting orbit (88710 2001 SL9), with positive value of the quadratic drift (the solution for the quadratic drift is ambiguous so far, with possible values of 5 and 8 deg/yr2).The spin configuration of the satellite play a crucial role in the evolution of the system under the influence of the BYORP effect. I will show that the rotational lightcurves of the satellites show that most of them have small libration amplitudes (up to 20 deg.), with a few interesting exceptions.Acknowledgements: This work has been supported by the Grant Agency of the Czech Republic, Grant P209

  11. Binary Sparse Phase Retrieval via Simulated Annealing

    Directory of Open Access Journals (Sweden)

    Wei Peng

    2016-01-01

    Full Text Available This paper presents the Simulated Annealing Sparse PhAse Recovery (SASPAR algorithm for reconstructing sparse binary signals from their phaseless magnitudes of the Fourier transform. The greedy strategy version is also proposed for a comparison, which is a parameter-free algorithm. Sufficient numeric simulations indicate that our method is quite effective and suggest the binary model is robust. The SASPAR algorithm seems competitive to the existing methods for its efficiency and high recovery rate even with fewer Fourier measurements.

  12. Inducing Risk Neutral Preferences with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2013-01-01

    We evaluate the binary lottery procedure for inducing risk neutral behavior. We strip the experimental implementation down to bare bones, taking care to avoid any potentially confounding assumptions about behavior having to be made. In particular, our evaluation does not rely on the assumed...... validity of any strategic equilibrium behavior, or even the customary independence axiom. We show that subjects sampled from our population are generally risk averse when lotteries are defined over monetary outcomes, and that the binary lottery procedure does indeed induce a statistically significant shift...... toward risk neutrality. This striking result generalizes to the case in which subjects make several lottery choices and one is selected for payment....

  13. Toroidal Horizons in Binary Black Hole Mergers

    OpenAIRE

    Bohn, Andy; Kidder, Lawrence E.; Teukolsky, Saul A.

    2016-01-01

    We find the first binary black hole event horizon with a toroidal topology. It had been predicted that generically the event horizons of merging black holes should briefly have a toroidal topology, but such a phase has never been seen prior to this work. In all previous binary black hole simulations, in the coordinate slicing used to evolve the black holes, the topology of the event horizon transitions directly from two spheres during the inspiral to a single sphere as the black holes merge. ...

  14. Binaries in the Hipparcos data: Keep digging

    OpenAIRE

    Pourbaix, D.; Jancart, S.; Jorissen, A.

    2004-01-01

    Among the 120 000 objects in the Hipparcos catalogue, only 235 were fitted with an orbital model. Besides these 235 original astrometric binaries, most Hipparcos entries with a known spectroscopic orbit (extrasolar planet or stellar companion) have now been re-processed, as part of the on-going construction of the 9th Catalogue of Spectroscopic Binary Orbits (SB9, available at http://sb9.astro.ulb.ac.be). The pitfalls and successes of this re-processing are discussed in various contexts, like...

  15. Apsidal motion in eclipsing binary GG Orionis

    Science.gov (United States)

    Yilan, E.; Bulut, I.

    2016-03-01

    The study of apsidal motion in binary stars with eccentric orbit is well known as an important source of information for the stellar internal structure as well as the possibility of verification of general relativity. In this study, the apsidal motion of the eccentric eclipsing binary GG Ori (P = 6.631 days, e = 0.22) has been analyzed using the times of minimum light taken from the literature and databases and the elements of apsidal motion have been computed. The method described by Giménez and García-Pelayo (1983) has been used for the apsidal motion analysis.

  16. Decomposition of Binary Signed-Graphic Matroids

    CERN Document Server

    Pitsoulis, Leonidas

    2010-01-01

    In this paper we employ Tutte's theory of bridges to derive a decomposition theorem for binary matroids arising from signed graphs. The proposed decomposition differs from previous decomposition results on matroids that have appeared in the literature in the sense that it is not based on $k$-sums, but rather on the operation of deletion of a cocircuit. Specifically, it is shown that certain minors resulting from the deletion of a cocircuit of a binary matroid will be graphic matroids apart from exactly one that will be signed-graphic, if and only if the matroid is signed-graphic.

  17. Quantitative spectroscopy of close binary stars

    CERN Document Server

    Pavlovski, K

    2011-01-01

    The method of spectral disentangling has now created the opportunity for studying the chemical composition in previously inaccessible components of binary and multiple stars. This in turn makes it possible to trace their chemical evolution, a vital aspect in understanding the evolution of stellar systems. We review different ways to reconstruct individual spectra from eclipsing and non-eclipsing systems, and then concentrate on some recent applications to detached binaries with high-mass and intermediate-mass stars, and Algol-type mass-transfer systems.

  18. Influence of some exo nucleases in response to the induced genetic damage in Escherichia coli by alpha radiation

    International Nuclear Information System (INIS)

    Within the strategies with those that E. coli counts to overcome to the genetic damage there is the SOS response, a group of genes that participate in repair and/or tolerance that it confers to the bacteria major opportunities of surviving. These genes are repressed and its only are expressed when it happens genetic damage. So that this system is activated it is necessary that DNA of a band exists and in this sense the double ruptures (RDB) its are not able to induce this response unless there is a previous processing. In stumps with defects in certain genes that have to do with repair of RDB (as recO, recJ and xonA) the activity of SOS is smaller than in a wild stump what suggests that these participate in the previous processes to the activation of the response. The ionizing radiation produce among other many lesions, RDB in greater or smaller proportion, depending on the ionization capacity. A parameter to evaluate this capacity is the lineal energy transfer (LET), defined as the average energy given by unit of distance travelled. In general the LET of the corpuscular radiations is a lot but high that of the electromagnetic one, for what produces bigger quantity of ionizations inside a restricted zone and it increases by this way the probability that RDB has been generated. This work has for object to infer the participation of xonA and recJ in this response and to evaluate the damage produced by ionizing radiation of different LET (alpha particles of different energies) in a stump with all the functional repair mechanisms. Its were considered two parameters: the survival and the activity of SOS evaluated by means of the chromo test. The results indicate that the activity of these exo nucleases is necessary for the repair of RDB as well as for the processing of lesions foresaw to the activation of SOS. As for the treatment with alphas of different energies is observed that so much the survival like the activity of SOS vary as the LET of the radiation changes

  19. Sample Processing technique onboard ExoMars (MOMA) to analyze organic compounds by Gas Chromatography-Mass Spectrometry

    Science.gov (United States)

    Buch, A.; Freissinet, C.; Sternberg, R.; Szopa, C.; Coll, P. J.; Brault, A.; Pinnick, V.; Siljeström, S.; Raulin, F.; Steininger, H.; Goesmann, F.; MOMA Team

    2011-12-01

    With the aim of separating and detecting organic compounds from Martian soil onboard the Mars Organic Molecule Analyzer (MOMA) experiment of the ExoMars 2018 upcoming joint ESA/NASA mission, we have developed three different space compatible sample preparation techniques compatible with space missions, able to extract and analyze by GC-MS a wide range of volatile and refractory compounds, including chirality analysis. Then, a sample processing utilizing three derivatization/extraction reactions has been carried out. The first reaction is based on a silyl reagent N-Methyl-N- (Tert-Butyldimethylsilyl)trifluoroacetamide (MTBSTFA) [1], the second one, N,N-Dimethylformamide Dimethylacetal (DMF-DMA) [2,3] is dedicated to the chirality detection and the third one is a thermochemolysis based on the use of tetramethylammoniumhydroxide (TMAH). The sample processing system is performed in an oven, dedicated to the MOMA experiment containing the solid sample (50-100mg). The internal temperature of the oven ranges from 20 to 900 °C. The extraction step is achieved by using thermodesorption in the range of 100 to 300°C for 5 to 20 min. Then, the chemical derivatization of the extracted compounds is performed directly on the soil sample by using a derivatyization capsule which contains a mixture of MTBSTFA-DMF or DMF-DMA solution when enantiomeric separation is required. By decreasing the polarity of the targeted molecules, this step allows their volatilization at a temperature below 250°C without any thermal degradation. Once derivatized, the volatile target molecules are trapped in a chemical trap and promptly desorbed into the gas chromatograph coupled to a mass spectrometer. Thermochemolysis is directly performed in the oven at 400°C during 5 min with a 25% (w/w) methanol solution of tetramethylammonium hydroxide (TMAH). Then, pyrolysis in the presence of TMAH allows both an efficient cleavage of polar bonds and the subsequent methylation of COOH, OH and NH2 groups, hence

  20. Neutron-Star-Black-Hole Binaries Produced by Binary-Driven Hypernovae.

    Science.gov (United States)

    Fryer, Chris L; Oliveira, F G; Rueda, J A; Ruffini, R

    2015-12-01

    Binary-driven hypernovae (BdHNe) within the induced gravitational collapse paradigm have been introduced to explain energetic (E_{iso}≳10^{52}  erg), long gamma-ray bursts (GRBs) associated with type Ic supernovae (SNe). The progenitor is a tight binary composed of a carbon-oxygen (CO) core and a neutron-star (NS) companion, a subclass of the newly proposed "ultrastripped" binaries. The CO-NS short-period orbit causes the NS to accrete appreciable matter from the SN ejecta when the CO core collapses, ultimately causing it to collapse to a black hole (BH) and producing a GRB. These tight binaries evolve through the SN explosion very differently than compact binaries studied in population synthesis calculations. First, the hypercritical accretion onto the NS companion alters both the mass and the momentum of the binary. Second, because the explosion time scale is on par with the orbital period, the mass ejection cannot be assumed to be instantaneous. This dramatically affects the post-SN fate of the binary. Finally, the bow shock created as the accreting NS plows through the SN ejecta transfers angular momentum, braking the orbit. These systems remain bound even if a large fraction of the binary mass is lost in the explosion (well above the canonical 50% limit), and even large kicks are unlikely to unbind the system. Indeed, BdHNe produce a new family of NS-BH binaries unaccounted for in current population synthesis analyses and, although they may be rare, the fact that nearly 100% remain bound implies that they may play an important role in the compact merger rate, important for gravitational waves that, in turn, can produce a new class of ultrashort GRBs. PMID:26684106

  1. Retrograde binaries of massive black holes in circum-binary accretion discs

    OpenAIRE

    Amaro-Seoane, Pau; Maureira-Fredes, Cristián; Dotti, Massimo; Colpi, Monica

    2016-01-01

    We explore the hardening of a massive black hole binary embedded in a circum-binary gas disc when the binary and the gas are coplanar and the gas is counter-rotating. The secondary black hole, revolving in the direction opposite to the gas, experiences a drag from gas-dynamical friction and from direct accretion of part of it. Using two-dimensional (2D) hydrodynamical grid simulations we investigate the effect of changing the accretion prescriptions on the dynamics of the secondary black hole...

  2. A Survey Design for a Sensitive Binary Variable Correlated with Another Nonsensitive Binary Variable

    OpenAIRE

    Jun-Wu Yu; Guo-Liang Tian; Yang Lu

    2013-01-01

    Tian et al. (2007) introduced a so-called hidden sensitivity model for evaluating the association of two sensitive questions with binary outcomes. However, in practice, we sometimes need to assess the association between one sensitive binary variable (e.g., whether or not a drug user, the number of sex partner being ⩽1 or >1, and so on) and one nonsensitive binary variable (e.g., good or poor health status, with or without cervical cancer, and so on). To address this issue, by sufficiently ut...

  3. Adiabatic Mass Loss Model in Binary Stars

    Science.gov (United States)

    Ge, H. W.

    2012-07-01

    Rapid mass transfer process in the interacting binary systems is very complicated. It relates to two basic problems in the binary star evolution, i.e., the dynamically unstable Roche-lobe overflow and the common envelope evolution. Both of the problems are very important and difficult to be modeled. In this PhD thesis, we focus on the rapid mass loss process of the donor in interacting binary systems. The application to the criterion of dynamically unstable mass transfer and the common envelope evolution are also included. Our results based on the adiabatic mass loss model could be used to improve the binary evolution theory, the binary population synthetic method, and other related aspects. We build up the adiabatic mass loss model. In this model, two approximations are included. The first one is that the energy generation and heat flow through the stellar interior can be neglected, hence the restructuring is adiabatic. The second one is that he stellar interior remains in hydrostatic equilibrium. We model this response by constructing model sequences, beginning with a donor star filling its Roche lobe at an arbitrary point in its evolution, holding its specific entropy and composition profiles fixed. These approximations are validated by the comparison with the time-dependent binary mass transfer calculations and the polytropic model for low mass zero-age main-sequence stars. In the dynamical time scale mass transfer, the adiabatic response of the donor star drives it to expand beyond its Roche lobe, leading to runaway mass transfer and the formation of a common envelope with its companion star. For donor stars with surface convection zones of any significant depth, this runaway condition is encountered early in mass transfer, if at all; but for main sequence stars with radiative envelopes, it may be encountered after a prolonged phase of thermal time scale mass transfer, so-called delayed dynamical instability. We identify the critical binary mass ratio for the

  4. Evolution of Binary Stars in Multiple-Population Globular Clusters

    CERN Document Server

    Hong, Jongsuk; Sollima, Antonio; McMillan, Stephen L W; D'Antona, Franca; D'Ercole, Annibale

    2015-01-01

    The discovery of multiple stellar populations in globular clusters has implications for all the aspects of the study of these stellar systems. In this paper, by means of N-body simulations, we study the evolution of binary stars in multiple-population clusters and explore the implications of the initial differences in the spatial distribution of different stellar populations for the evolution and survival of their binary stars. Our simulations show that initial differences between the spatial distribution of first-generation (FG) and second-generation (SG) stars can leave a fingerprint in the current properties of the binary population. SG binaries are disrupted more efficiently than those of the FG population resulting in a global SG binary fraction smaller than that of the FG. As for surviving binaries, dynamical evolution produces a difference between the SG and the FG binary binding energy distribution with the SG population characterized by a larger fraction of high binding energy (more bound) binaries. ...

  5. Model-independent inference on compact-binary observations

    CERN Document Server

    Mandel, Ilya; Colonna, Andrea; Stevenson, Simon; Tiňo, Peter; Veitch, John

    2016-01-01

    The recent advanced LIGO detections of gravitational waves from merging binary black holes enhance the prospect of exploring binary evolution via gravitational-wave observations of a population of compact-object binaries. In the face of uncertainty about binary formation models, model-independent inference provides an appealing alternative to comparisons between observed and modelled populations. We describe a procedure for clustering in the multi-dimensional parameter space of observations that are subject to significant measurement errors. We apply this procedure to a mock data set of population-synthesis predictions for the masses of merging compact binaries convolved with realistic measurement uncertainties, and demonstrate that we can accurately distinguish subpopulations of binary neutron stars, binary black holes, and mixed black hole -- neutron star binaries.

  6. BINARY ASTEROID ENCOUNTERS WITH TERRESTRIAL PLANETS: TIMESCALES AND EFFECTS

    International Nuclear Information System (INIS)

    Many asteroids that make close encounters with terrestrial planets are in a binary configuration. Here, we calculate the relevant encounter timescales and investigate the effects of encounters on a binary's mutual orbit. We use a combination of analytical and numerical approaches with a wide range of initial conditions. Our test cases include generic binaries with close, moderate, and wide separations, as well as seven well-characterized near-Earth binaries. We find that close approaches (<10 Earth radii) occur for almost all binaries on 1-10 million year timescales. At such distances, our results suggest substantial modifications to a binary's semimajor axis, eccentricity, and inclination, which we quantify. Encounters within 30 Earth radii typically occur on sub-million year timescales and significantly affect the wider binaries. Important processes in the lives of near-Earth binaries, such as tidal and radiative evolution, can be altered or stopped by planetary encounters.

  7. Formation and evolution of X-ray binaries

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We review recent progress in theoretical understanding of X-ray binaries,which has largely been driven by new observations.We select several topics including formation of compact low-mass X-ray binaries,the evolutionary connection between low-mass X-ray binaries and binary and millisecond radio pulsars,and ultraluminous X-ray sources,to illustrate the interplay between theories and observations.

  8. Binary Solid-Liquid Phase Equilibria

    Science.gov (United States)

    Ellison, Herbert R.

    1978-01-01

    Indicates some of the information that may be obtained from a binary solid-liquid phase equilibria experiment and a method to write a computer program that will plot an ideal phase diagram to which the experimental results may be compared. (Author/CP)

  9. The Environment of Binary Nuetron Star Mergers

    Science.gov (United States)

    Wiggins, Brandon

    2016-04-01

    In addition to detections by LIGO, binary neutron star mergers may be detected via luminous interaction with surrounding interstellar media. Upcoming observations including the VLASS survey may be able to detect such interactions and offer constraints on the binary neutron star merger rate. In this talk, I will present the results of cosmological simulations of a cluster of galaxies followed down to redshift 0. Our calculation includes star formation from which we infer a supernova and binary neutron star production rate. Using pre-existing models of neutron star binaries, we follow the positions of neutron star pairs in the cluster potential throughout cosmic time allowing us to identify regions in which neutron stars merge. We present statistics of many Monte Carlo instances of nuetron star pairs and trajectories allowing us to constrain the approximate fraction of neutron stars merging in dense gas. Our work has implications for R-process enrichment of galaxies in addition to predicting electromagnetic counterparts to gravitational wave detections of neutron star mergers.

  10. The Evolution of Relativistic Binary Progenitor Systems

    CERN Document Server

    Francischelli, G J; Brown, G E

    2001-01-01

    Relativistic binary pulsars, such as B1534+12 and B1913+16 are characterized by having close orbits with a binary separation of ~ 3 R_\\sun. The progenitor of such a system is a neutron star, helium star binary. The helium star, with a strong stellar wind, is able to spin up its compact companion via accretion. The neutron star's magnetic field is then lowered to observed values of about 10^{10} Gauss. As the pulsar lifetime is inversely proportional to its magnetic field, the possibility of observing such a system is, thus, enhanced by this type of evolution. We will show that a nascent (Crab-like) pulsar in such a system can, through accretion-braking torques (i.e. the "propeller effect") and wind-induced spin-up rates, reach equilibrium periods that are close to observed values. Such processes occur within the relatively short helium star lifetimes. Additionally, we find that the final outcome of such evolutionary scenarios depends strongly on initial parameters, particularly the initial binary separation a...

  11. The Binary Pulsar: Gravity Waves Exist.

    Science.gov (United States)

    Will, Clifford

    1987-01-01

    Reviews the history of pulsars generally and the 1974 discovery of the binary pulsar by Joe Taylor and Russell Hulse specifically. Details the data collection and analysis used by Taylor and Hulse. Uses this discussion as support for Albert Einstein's theory of gravitational waves. (CW)

  12. A Binary Teetering on the Edge

    Science.gov (United States)

    Motl, P. M.; D'Souza, M. C. R.; Tohline, J. E.; Frank, J.

    2005-05-01

    We present a fully three-dimensional hydrodynamical simulation of Roche lobe overflow in a binary near the stability boundary. This boundary separates evolutionary branches that correspond to either an accelerating mass transfer rate leading eventually to merger through tidal instability or to a decaying mass transfer rate as the orbit expands. The binary begins with a mass ratio of 0.4 (ratio of donor to accretor mass) and is initially assumed to be rotating synchronously. We treat the stellar components as simple polytropic fluids characterized by a polytropic index, n = 3/2. As the donor overflows its Roche lobe, the mass transfer rate initially accelerates before stabilizing and eventually dropping over a timescale of tens of orbits. We also note that for this particular binary, the accretion stream impacts on the surface of the donor rather than forming an accretion disk. This simulation allows us to measure the efficiency with which the accretion stream spins up the accretor in this "direct impact" scenario and the degree to which angular momentum is transfered back to the binary orbit via the tidal field.

  13. Pedestrian Detection Using Gradient Local Binary Patterns

    Science.gov (United States)

    Jiang, Ning; Xu, Jiu; Goto, Satoshi

    In recent years, local pattern based features have attracted increasing interest in object detection and recognition systems. Local Binary Pattern (LBP) feature is widely used in texture classification and face detection. But the original definition of LBP is not suitable for human detection. In this paper, we propose a novel feature named gradient local binary patterns (GLBP) for human detection. In this feature, original 256 local binary patterns are reduced to 56 patterns. These 56 patterns named uniform patterns are used for generating a 56-bin histogram. And gradient value of each pixel is set as the weight which is always same in LBP based features in histogram calculation to computing the values in 56 bins for histogram. Experiments are performed on INRIA dataset, which shows the proposal GLBP feature is discriminative than histogram of orientated gradient (HOG), Semantic Local Binary Patterns (S-LBP) and histogram of template (HOT). In our experiments, the window size is fixed. That means the performance can be improved by boosting methods. And the computation of GLBP feature is parallel, which make it easy for hardware acceleration. These factors make GLBP feature possible for real-time pedestrian detection.

  14. Binary translation using peephole translation rules

    Science.gov (United States)

    Bansal, Sorav; Aiken, Alex

    2010-05-04

    An efficient binary translator uses peephole translation rules to directly translate executable code from one instruction set to another. In a preferred embodiment, the translation rules are generated using superoptimization techniques that enable the translator to automatically learn translation rules for translating code from the source to target instruction set architecture.

  15. Flip-flopping binary black holes.

    Science.gov (United States)

    Lousto, Carlos O; Healy, James

    2015-04-10

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes. PMID:25910104

  16. Numerical simulations of compact object binaries

    OpenAIRE

    Pfeiffer, Harald P.

    2012-01-01

    Coalescing compact object binaries consisting of black holes and/or Neutron stars are a prime target for ground-based gravitational wave detectors. This article reviews the status of numerical simulations of these systems, with an emphasis on recent progress.

  17. PARTICLE SEGREGATION IN FLUIDIZED BINARY-MIXTURES

    NARCIS (Netherlands)

    HOFFMANN, AC; JANSSEN, LPBM

    1993-01-01

    The particle segregation in fluidised beds consisting of different types of binary mixtures is shown to be governed by the same particle transport processes. The segregation behaviour of both ''different-density mixtures'' and ''equal-density mixtures'', two types of system which until now largely h

  18. Planetary nebula progenitors that swallow binary systems

    CERN Document Server

    Soker, Noam

    2015-01-01

    I propose that some irregular `messy' planetary nebulae owe their morphologies to triple-stellar evolution where tight binary systems are tidally and frictionally destroyed inside the envelope of asymptotic giant branch (AGB) stars. The tight binary system might breakup with one star leaving the system. In an alternative evolution, one of the stars of the brook-up tight binary system falls toward the AGB envelope with low specific angular momentum, and drowns in the envelope. In a different type of destruction process the drag inside the AGB envelope causes the tight binary system to merge. This releases gravitational energy within the AGB envelope, leading to a very asymmetrical envelope ejection, with an irregular and `messy' planetary nebula as a descendant. The evolution of the triple-stellar system before destruction can be in a full common envelope evolution (CEE) or in a grazing envelope evolution (GEE). Both before and after destruction the system might lunch pairs of opposite jets. One pronounced sig...

  19. Locating Restricted Facilities on Binary Maps

    CERN Document Server

    Andreica, Mugurel Ionut; Andreica, Madalina Ecaterina

    2008-01-01

    In this paper we consider several facility location problems with applications to cost and social welfare optimization, when the area map is encoded as a binary (0,1) mxn matrix. We present algorithmic solutions for all the problems. Some cases are too particular to be used in practical situations, but they are at least a starting point for more generic solutions.

  20. Cassini states for black hole binaries

    Science.gov (United States)

    Correia, Alexandre C. M.

    2016-03-01

    Cassini states correspond to the equilibria of the spin axis of a body when its orbit is perturbed. They were initially described for planetary satellites, but the spin axes of black hole binaries also present this kind of equilibria. In previous works, Cassini states were reported as spin-orbit resonances, but actually the spin of black hole binaries is in circulation and there is no resonant motion. Here we provide a general description of the spin dynamics of black hole binary systems based on a Hamiltonian formalism. In absence of dissipation, the problem is integrable and it is easy to identify all possible trajectories for the spin for a given value of the total angular momentum. As the system collapses due to radiation reaction, the Cassini states are shifted to different positions, which modifies the dynamics around them. This is why the final spin distribution may differ from the initial one. Our method provides a simple way of predicting the distribution of the spin of black hole binaries at the end of the inspiral phase.

  1. Non-binary or genderqueer genders.

    Science.gov (United States)

    Richards, Christina; Bouman, Walter Pierre; Seal, Leighton; Barker, Meg John; Nieder, Timo O; T'Sjoen, Guy

    2016-01-01

    Some people have a gender which is neither male nor female and may identify as both male and female at one time, as different genders at different times, as no gender at all, or dispute the very idea of only two genders. The umbrella terms for such genders are 'genderqueer' or 'non-binary' genders. Such gender identities outside of the binary of female and male are increasingly being recognized in legal, medical and psychological systems and diagnostic classifications in line with the emerging presence and advocacy of these groups of people. Population-based studies show a small percentage--but a sizable proportion in terms of raw numbers--of people who identify as non-binary. While such genders have been extant historically and globally, they remain marginalized, and as such--while not being disorders or pathological in themselves--people with such genders remain at risk of victimization and of minority or marginalization stress as a result of discrimination. This paper therefore reviews the limited literature on this field and considers ways in which (mental) health professionals may assist the people with genderqueer and non-binary gender identities and/or expressions they may see in their practice. Treatment options and associated risks are discussed. PMID:26753630

  2. Eclipsing Binaries with the Kepler Mission

    Science.gov (United States)

    Prsa, Andrej; Kepler Eclipsing Binary Working Group

    2012-05-01

    Kepler has revolutionized the eclipsing binary field by providing us essentially uninterrupted data of unprecedented quality. Out of 160,000 targets, we detected over 2500 eclipsing binaries. These range in orbital periods from as short as 0.3 days, all the way to several years, and encompass stellar types across the H-R diagram. In this talk I will present the collaborative effort of the Kepler Eclipsing Binary Working Group to study and characterize these systems on a statistical level: their distribution in periods, galactic latitude, spectral type, fundamental stellar properties and multiplicity as evidenced by eclipse timing variations. I will further show the gems that have sprung from this sample, which were modeled and interpreted to reveal intrinsically pulsating components, runaway encounters with massive tertiaries, stellar objects that populate the lowest end of the main sequence and circumbinary planets. I will critically review and discuss the causes of data systematics and detrending, and introduce a novel algorithm to classify light curves into morphological types using Locally Linear Embedding. Finally, I will touch on the dark side of eclipsing binaries as the primary cause of false positives in extrasolar planet detections with Kepler.

  3. Spin frequency distributions of binary millisecond pulsars

    NARCIS (Netherlands)

    A. Papitto; D.F. Torres; N. Rea; T.M. Tauris

    2014-01-01

    Rotation-powered millisecond radio pulsars have been spun up to their present spin period by a 108−109 yr long X-ray-bright phase of accretion of matter and angular momentum in a low-to-intermediate mass binary system. Recently, the discovery of transitional pulsars that alternate cyclically between

  4. Short-timescale variability in cataclysmic binaries

    International Nuclear Information System (INIS)

    Rapid variability, including flickering and pulsations, has been detected in cataclysmic binaries at optical and x-ray frequencies. In the case of the novalike variable TT Arietis, simultaneous observations reveal that the x-ray and optical flickering activity is strongly correlated, while short period pulsations are observed that occur at the same frequencies in both wavelength bands

  5. Cassini states for black-hole binaries

    CERN Document Server

    Correia, Alexandre C M

    2016-01-01

    Cassini states correspond to equilibria of the spin axis of a celestial body when its orbit is perturbed. They were initially described for planetary satellites, but the spin axes of black-hole binaries also present this kind of equilibria. In previous works, Cassini states were reported as spin-orbit resonances, but actually the spin of black-hole binaries is in circulation and there is no resonant motion. Here we provide a general description of the spin dynamics of black-hole binary systems based on a Hamiltonian formalism. In absence of dissipation the problem is integrable and it is easy to identify all possible trajectories for the spin for a given value of the total angular momentum. As the system collapses due to radiation reaction, the Cassini states are shifted to different positions, which modifies the dynamics around them. This is why the final spin distribution may differ from the initial one. Our method provides a simple way of predicting the distribution of the spin of black-hole binaries at th...

  6. Supermassive Black Hole Binaries: The Search Continues

    CERN Document Server

    Bogdanovic, Tamara

    2014-01-01

    Gravitationally bound supermassive black hole binaries (SBHBs) are thought to be a natural product of galactic mergers and growth of the large scale structure in the universe. They however remain observationally elusive, thus raising a question about characteristic observational signatures associated with these systems. In this conference proceeding I discuss current theoretical understanding and latest advances and prospects in observational searches for SBHBs.

  7. Binary nucleation of water and sodium chloride

    Czech Academy of Sciences Publication Activity Database

    Němec, Tomáš; Maršík, František; Palmer, A.

    2006-01-01

    Roč. 124, č. 4 (2006), 0445091-0445096. ISSN 0021-9606 R&D Projects: GA ČR(CZ) GA101/05/2536 Institutional research plan: CEZ:AV0Z20760514 Keywords : binary nucleation * sodium chloride * water Subject RIV: BJ - Thermodynamics Impact factor: 3.166, year: 2006

  8. Generating quality tetrahedral meshes from binary volumes

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Bærentzen, Jakob Andreas; Larsen, Rasmus

    2010-01-01

    use these measures to generate high quality meshes from signed distance maps. This paper also describes an approach for computing (smooth) signed distance maps from binary volumes as volumetric data in many cases originate from segmentation of objects from imaging techniques such as CT, MRI, etc. The...

  9. Binary pulsars as dark-matter probes

    CERN Document Server

    Pani, Paolo

    2015-01-01

    During the motion of a binary pulsar around the galactic center, the pulsar and its companion experience a wind of dark-matter particles that can affect the orbital motion through dynamical friction. We show that this effect produces a characteristic seasonal modulation of the orbit and causes a secular change of the orbital period whose magnitude can be well within the astonishing precision of various binary-pulsar observations. Our analysis is valid for binary systems with orbital period longer than a day. By comparing this effect with pulsar-timing measurements, it is possible to derive model-independent upper bounds on the dark-matter density at different distances $D$ from the galactic center. For example, the precision timing of J1713+0747 imposes $\\rho_{\\rm DM}\\lesssim 10^5\\,{\\rm GeV/cm}^3$ at $D\\approx7\\,{\\rm kpc}$. The detection of a binary pulsar at $D\\lesssim 10\\,{\\rm pc}$ could provide stringent constraints on dark-matter halo profiles and on growth models of the central black hole. The Square Kil...

  10. Testing the Binary Trigger Hypothesis in FUors

    CERN Document Server

    Green, Joel D; Rizzuto, Aaron C; Ireland, Michael J; Dupuy, Trent J; Mann, Andrew W; Kuruwita, Rajika

    2016-01-01

    We present observations of three FU Orionis objects (hereafter, FUors) with nonredundant aperture-mask interferometry (NRM) at 1.59 um and 2.12 um that probe for binary companions on the scale of the protoplanetary disk that feeds their accretion outbursts. We do not identify any companions to V1515 Cyg or HBC 722, but we do resolve a close binary companion to V1057 Cyg that is at the diffraction limit (rho = 58.3 +/- 1.4 mas or 30 +/- 5 AU) and currently much fainter than the outbursting star (delta(K') = 3.34 +/- 0.10 mag). Given the flux excess of the outbursting star, we estimate that the mass of the companion (M ~ 0.25 Msun) is similar to or slightly below that of the FUor itself, and therefore it resembles a typical T Tauri binary system. Our observations only achieve contrast limits of delta(K') ~ 4 mag, and hence we are only sensitive to companions that were near or above the pre-outburst luminosity of the FUors. It remains plausible that FUor outbursts could be tied to the presence of a close binary ...

  11. Constraining Binary Stellar Evolution With Pulsar Timing

    Science.gov (United States)

    Ferdman, Robert D.; Stairs, I. H.; Backer, D. C.; Burgay, M.; Camilo, F.; D'Amico, N.; Demorest, P.; Faulkner, A.; Hobbs, G.; Kramer, M.; Lorimer, D. R.; Lyne, A. G.; Manchester, R.; McLaughlin, M.; Nice, D. J.; Possenti, A.

    2006-06-01

    The Parkes Multibeam Pulsar Survey has yielded a significant number of very interesting binary and millisecond pulsars. Two of these objects are part of an ongoing timing study at the Green Bank Telescope (GBT). PSR J1756-2251 is a double-neutron star (DNS) binary system. It is similar to the original Hulse-Taylor binary pulsar system PSR B1913+16 in its orbital properties, thus providing another important opportunity to test the validity of General Relativity, as well as the evolutionary history of DNS systems through mass measurements. PSR J1802-2124 is part of the relatively new and unstudied "intermediate-mass" class of binary system, which typically have spin periods in the tens of milliseconds, and/or relatively massive (> 0.7 solar masses) white dwarf companions. With our GBT observations, we have detected the Shapiro delay in this system, allowing us to constrain the individual masses of the neutron star and white dwarf companion, and thus the mass-transfer history, in this unusual system.

  12. Performance of binary FSK data transmission systems

    Science.gov (United States)

    Batson, B. H.

    1973-01-01

    Matched-filter detection of binary signals is discussed in terms of the probability of bit error. The equations for the probability of error are derived for coherent phase shift keying, and coherent frequency shift keying (FSK). Suboptimum detection of FSK signals is also discussed for discriminators.

  13. BINARY WAVELET TRANSFORM FOR IMAGE REPRESENTATION

    Directory of Open Access Journals (Sweden)

    ASHOK.M

    2011-08-01

    Full Text Available The MRA (Multi resolution analysis for an image provides specific information localized in space or frequency domain .In this paper an efficient representation of the visual information is presented using Binary wavelet Transform for both color and gray level image. Analytical results shows that this method proves to be more efficient in representing the visual information than the earlier

  14. A semantic constraint on binary determiners

    OpenAIRE

    Zuber, Richard

    2009-01-01

    Abstract A type $${\\langle{1^2, 1}\\rangle}$$ quantifier F is symmetric iff F(X, X)(Y) = F(Y, Y)(X). It is shown that quantifiers denoted by irreducible binary determiners in natural languages are both conservative and symmetric and not only conservative.

  15. Orbits of Ten Visual Binary Stars

    Institute of Scientific and Technical Information of China (English)

    B.Novakovi(c)

    2007-01-01

    We present the orbits of ten visual binary stars:WDS 01015+6922.WDS 01424-0645,WDS 01461+6349,WDS 04374-0951,WDS 04478+5318,WDS 05255-0033,WDS 05491+6248,WDS 06404+4058,WDS 07479-1212,and WDS 18384+0850.We have also determined their masses,dynamical parallaxes and ephemerides.

  16. The Benchmark Eclipsing Binary V530 Ori

    DEFF Research Database (Denmark)

    Torres, Guillermo; Lacy, Claud H. Sandberg; Pavlovski, Kresimir;

    2015-01-01

    We report accurate measurements of the physical properties (mass, radius, temperature) of components of the G+M eclipsing binary V530 On. The M-type secondary shows a larger radius and a cooler temperature than predicted by standard stellar evolution models, as has been found for many other low-m...

  17. Cluster selection in binary nuclear models

    CERN Document Server

    Buck, B; Pérez, S M

    2000-01-01

    We present a simple prescription for selecting the cluster and core in a binary cluster-model description of a nucleus. The prescription reproduces the cluster-core combinations used in earlier successful applications of the model, predicts others, and extends the good agreement previously found with observed B(E2; 2 sup + -> 0 sup +) values of actinide nuclei. Refs. 31 (author)

  18. Merging Compact Binaries in Hierarchical Triple Systems: Resonant Excitation of Binary Eccentricity

    CERN Document Server

    Liu, Bin; Yuan, Ye-Fei

    2015-01-01

    The merging of compact binaries play an important role in astrophysical context. The gravitational waves takes the angular momentum off the merging binary, which makes the orbit of the inner binary shrink. In this work, we study the secular dynamics of merging binary with a small perturber in hierarchical triple systems. From our numerical calculations, we find that the triple system goes through a resonant state between the apsidal precession rates of two orbits during the orbital decay, and the eccentricity of the inner orbit is excited, as well as the corresponding gravita- tional wave frequency. Our numerical results could be understood under the linear approximation of small orbital eccentricities and coplanar configuration. Especially, the resonant condition and the excited eccentricity can be estimated analytically.

  19. Infalling clouds on to supermassive black hole binaries - II. Binary evolution and the final parsec problem

    CERN Document Server

    Goicovic, Felipe G; Cuadra, Jorge; Stasyszyn, Federico

    2016-01-01

    The formation of massive black hole binaries (MBHBs) is an unavoidable outcome of galaxy evolution via successive mergers. However, the mechanism that drives their orbital evolution from parsec separations down to the gravitational wave (GW) dominated regime is poorly understood and their final fate is still unclear. If such binaries are embedded in gas-rich and turbulent environments, as observed in remnants of galaxy mergers, the interaction with gas clumps (such as molecular clouds) may efficiently drive their orbital evolution. Using numerical simulations, we test this hypothesis by studying the dynamical evolution of an equal-mass, circular MBHB accreting infalling molecular clouds. We investigate different orbital configurations, modelling a total of 13 systems to explore different possible pericentre distances and relative inclinations of the cloud-binary encounter. We show that the evolution of the binary orbit is dominated by the exchange of angular momentum through gas accretion during the first sta...

  20. Radio evidence for binary super massive black holes

    Science.gov (United States)

    Ekers, R. D.

    2016-02-01

    I present examples of radio AGN with binary nuclei which provide the direct radio evidence for binary Super Massive Black Holes (SMBH) driving the AGN activity. There is also other evidence for distorted radio morphology and periodic variability which may indicate the presence of a second (inactive) SMBH. Finally I enumerate a number of possible radio tracers for the binary SMBH merger events.

  1. Kepler Eclipsing Binary Stars. VIII. Identification of False Positive Eclipsing Binaries and Re-extraction of New Light Curves

    CERN Document Server

    Abdul-Masih, Michael; Conroy, Kyle; Bloemen, Steven; Boyajian, Tabetha; Doyle, Laurance R; Johnston, Cole; Kostov, Veselin; Latham, David W; Matijevic, Gal; Shporer, Avi; Southworth, John

    2016-01-01

    The Kepler Mission has provided unprecedented, nearly continuous photometric data of $\\sim$200,000 objects in the $\\sim$105 deg$^{2}$ field of view from the beginning of science operations in May of 2009 until the loss of the second reaction wheel in May of 2013. The Kepler Eclipsing Binary Catalog contains information including but not limited to ephemerides, stellar parameters and analytical approximation fits for every known eclipsing binary system in the Kepler Field of View. Using Target Pixel level data collected from Kepler in conjunction with the Kepler Eclipsing Binary Catalog, we identify false positives among eclipsing binaries, i.e. targets that are not eclipsing binaries themselves, but are instead contaminated by eclipsing binary sources nearby on the sky and show eclipsing binary signatures in their light curves. We present methods for identifying these false positives and for extracting new light curves for the true source of the observed binary signal. For each source, we extract three separa...

  2. A decoding method of an n length binary BCH code through (n + 1n length binary cyclic code

    Directory of Open Access Journals (Sweden)

    TARIQ SHAH

    2013-09-01

    Full Text Available For a given binary BCH code Cn of length n = 2 s - 1 generated by a polynomial of degree r there is no binary BCH code of length (n + 1n generated by a generalized polynomial of degree 2r. However, it does exist a binary cyclic code C (n+1n of length (n + 1n such that the binary BCH code Cn is embedded in C (n+1n . Accordingly a high code rate is attained through a binary cyclic code C (n+1n for a binary BCH code Cn . Furthermore, an algorithm proposed facilitates in a decoding of a binary BCH code Cn through the decoding of a binary cyclic code C (n+1n , while the codes Cn and C (n+1n have the same minimum hamming distance.

  3. Binary Disk interaction II: Gap-Opening criteria for unequal mass binaries

    CERN Document Server

    del Valle, Luciano

    2013-01-01

    We study the interaction between an unequal mass binary with an isothermal circumbinary disk, motivated by the theoretical and observational evidence that after a major merger of gas-rich galaxies, a massive gaseous disk with a SMBH binary will be formed in the nuclear region. We focus on the gravitational torques that the binary exerts onto the disk and how these torques can drive the formation of a gap in the disk. This exchange of angular momentum between the binary and the disk is mainly driven by the gravitational interaction between the binary and a strong non-axisymmetric density perturbation that is produced in the disk, as response to the presence of the binary. Using SPH numerical simulations we tested two gap-opening criterion, one that assumes that the geometry of the density perturbation is an ellipsoid/thick-spirals and another that assumes a geometry of flat-spirals for the density perturbation. We find that the flat-spirals gap opening criterion successfully predicts which simulations will hav...

  4. Binaries migrating in a gaseous disk: Where are the Galactic center binaries?

    CERN Document Server

    Baruteau, C; Lin, D N C

    2010-01-01

    The massive stars in the Galactic center inner arcsecond share analogous properties with the so-called Hot Jupiters. Most of these young stars have highly eccentric orbits, and were probably not formed in-situ. It has been proposed that these stars acquired their current orbits from the tidal disruption of compact massive binaries scattered toward the proximity of the central supermassive black hole. Assuming a binary star formed in a thin gaseous disk beyond 0.1 pc from the central object, we investigate the relevance of disk-satellite interactions to harden the binding energy of the binary, and to drive its inward migration. A massive, equal-mass binary star is found to become more tightly wound as it migrates inwards toward the central black hole. The migration timescale is very similar to that of a single-star satellite of the same mass. The binary's hardening is caused by the formation of spiral tails lagging the stars inside the binary's Hill radius. We show that the hardening timescale is mostly determ...

  5. Habitat management affects soil chemistry and allochthonous organic inputs mediating microbial structure and exo-enzyme activity in Wadden Sea salt-marsh soils

    Science.gov (United States)

    Mueller, Peter; Granse, Dirk; Thi Do, Hai; Weingartner, Magdalena; Nolte, Stefanie; Hoth, Stefan; Jensen, Kai

    2016-04-01

    The Wadden Sea (WS) region is Europe's largest wetland and home to approximately 20% of its salt marsh area. Mainland salt marshes of the WS are anthropogenically influenced systems and have traditionally been used for livestock grazing in wide parts. After foundation of WS National Parks in the late 1980s and early 1990s, artificial drainage has been abandoned; however, livestock grazing is still common in many areas of the National Parks and is under ongoing discussion as a habitat-management practice. While studies so far focused on effects of livestock grazing on biodiversity, little is known about how biogeochemical processes, element cycling, and particularly carbon sequestration are affected. Here, we present data from a recent field study focusing on grazing effects on soil properties, microbial exo-enzyme activity, microbial abundance and structure. Exo-enzyme activity was studied conducting digestive enzyme assays for various enzymes involved in C- and N cycling. Microbial abundance and structure was assessed measuring specific gene abundance of fungi and bacteria using quantitative PCR. Soil compaction induced by grazing led to higher bulk density and decreases in soil redox (∆ >100 mV). Soil pH was significantly lower in grazed parts. Further, the proportion of allochthonous organic matter (marine input) was significantly smaller in grazed vs. ungrazed sites, likely caused by a higher sediment trapping capacity of the taller vegetation in the ungrazed sites. Grazing induced changes in bulk density, pH and redox resulted in reduced activity of enzymes involved in microbial C acquisition; however, there was no grazing effect on enzymes involved in N acquisition. While changes in pH, bulk density or redox did not affect microbial abundance and structure, the relative amount of marine organic matter significantly reduced the relative abundance of fungi (F:B ratio). We conclude that livestock grazing directly affects microbial exo-enzyme activity, thus

  6. Development of a Fully Integrated Lab-on-a-Chip Electrophoresis System for ExoMars and Future Astrobiology Missions

    Science.gov (United States)

    Willis, P. A.; Fisher, A.; Greer, F.; Grunthaner, F. J.; Hoppe, D.; Chiesl, T.; Mathies, R. A.; Rolland, J. P.

    2009-04-01

    This paper will describe current and future development efforts in lab-on-a-chip instrumentation for astrobiological investigations underway at JPL. We will begin with a discussion of the current technology status of our autonomous microfluidic capillary electrophoresis (μCE) system integrated with on-chip perfluoropolyether (PFPE) membrane valves and pumps [1], as part of the Urey Instrument. This work builds on the μCE system developed by Skelley et al. [2], but extends the system capability through the use of bio- and spaceflight-compatible PFPE-membrane valves rather than utilizing a PDMS-based approach. The ultimate goal of this μCE system is to perform ultrasensitive compositional and chiral analysis of amino acids in order to determine if Mars harbors signatures of past or present life. An autonomously functioning flight version of this instrument will examine extracts from the Martian regolith as part of the Pasteur Payload of the 2016 ExoMars astrobiology mission. The four-layer wafer stack design utilizes independent CE channels patterned in glass, along with a PFPE membrane, a pneumatic manifold layer, and a fluidic bus layer. Three pneumatically driven on-chip diaphragm valves placed in series are used to peristaltically pump reagents, buffers, and samples to and from capillary electrophoresis electrode well positions. Electrophoretic separation occurs in the all-glass channels near the base of the structure. The valve geometries and layouts in our integrated two-channel PFPE system have been optimized for valve sealing characteristics and uniform device spacing across the wafer surface. This paper will discuss current experimental development work in our research group involving further integration of functionality into an autonomous multi-channel system with no human intervention, enabling CE analysis upon a dried sample after receipt of a single pre-programmed instruction set from the user. The key structure under current development is an

  7. The ExoMars Trace Gas Orbiter NOMAD Spectrometer Suite for Nadir and Solar Occultation Observations of Mars' Atmosphere

    Science.gov (United States)

    Thomas, Ian; Carine Vandaele, Ann; López-Moreno, José Juan; Patel, Manish; Bellucci, Giancarlo; Drummond, Rachel; Neefs, Eduard; Depiesse, Cedric; Daerden, Frank; Rodriguez-Gómez, Julio; Neary, Lori; Robert, Séverine; Willame, Yannick; Mahieux, Arnaud

    2015-04-01

    NOMAD (Nadir and Occultation for MArs Discovery) is one of four instruments on board the ExoMars Trace Gas Orbiter, scheduled for launch in January 2016 and to begin nominal science mission around Mars in late 2017. It consists of a suite of three high-resolution spectrometers - Solar Occultation (SO), LNO (Limb Nadir and Occultation) and UVIS (Ultraviolet-Visible) - which will generate a huge dataset of Martian atmospheric observations during the mission, across a wide spectral range. Specifically, the SO spectrometer channel will perform occultation measurements, operating between 2.2-4.3μm at a resolution of 0.15cm-1, with 180-1000m vertical spatial resolution and an SNR of 1500-3000. LNO will perform limb scanning, nadir and occultation measurements, operating between 2.2-3.8μm at a resolution of 0.3cm-1. In nadir, global coverage will extend between ±74O latitude with an IFOV of 0.5x17km on the surface. This channel can also make occultation measurements should the SO channel fail. UVIS will make limb, nadir and occultation measurements between 200-650nm, at a resolution of 1nm. It will have 300-1000m vertical resolution during occultation and 5x60km ground resolution during 15s nadir observations. An order-of-magnitude increase in spectral resolution over previous instruments will allow NOMAD to map previously unresolvable gas species, such as important trace gases and isotopes. CO, CO2, H2O, C2H2, C2H4, C2H6, H2CO, CH4, SO2, H2S, HCl, O3 and several isotopologues of methane and water will be detectable, providing crucial measurements of the Martian D/H and methane isotope ratios. It will also be possible to map the sources and sinks of these gases, such as regions of surface volcanism/outgassing and atmospheric production, over the course of an entire Martian year, to further constrain atmospheric dynamics and climatology. NOMAD will also continue to monitor the Martian water, carbon, ozone and dust cycles, extending existing datasets made by successive

  8. White-light Flares on Close Binaries Observed with Kepler

    Science.gov (United States)

    Gao, Qing; Xin, Yu; Liu, Ji-Feng; Zhang, Xiao-Bin; Gao, Shuang

    2016-06-01

    Based on Kepler data, we present the results of a search for white light flares on 1049 close binaries. We identify 234 flare binaries, of which 6818 flares are detected. We compare the flare-binary fraction in different binary morphologies (“detachedness”). The result shows that the fractions in over-contact and ellipsoidal binaries are approximately 10%–20% lower than those in detached and semi-detached systems. We calculate the binary flare activity level (AL) of all the flare binaries, and discuss its variations along the orbital period (P orb) and rotation period (P rot, calculated for only detached binaries). We find that the AL increases with decreasing P orb or P rot, up to the critical values at P orb ∼ 3 days or P rot ∼ 1.5 days, and thereafter the AL starts decreasing no matter how fast the stars rotate. We examine the flaring rate as a function of orbital phase in two eclipsing binaries on which a large number of flares are detected. It appears that there is no correlation between flaring rate and orbital phase in these two binaries. In contrast, when we examine the function with 203 flares on 20 non-eclipse ellipsoidal binaries, bimodal distribution of amplitude-weighted flare numbers shows up at orbital phases 0.25 and 0.75. Such variation could be larger than what is expected from the cross section modification.

  9. Detectability of Gravitational Waves from High-Redshift Binaries.

    Science.gov (United States)

    Rosado, Pablo A; Lasky, Paul D; Thrane, Eric; Zhu, Xingjiang; Mandel, Ilya; Sesana, Alberto

    2016-03-11

    Recent nondetection of gravitational-wave backgrounds from pulsar timing arrays casts further uncertainty on the evolution of supermassive black hole binaries. We study the capabilities of current gravitational-wave observatories to detect individual binaries and demonstrate that, contrary to conventional wisdom, some are, in principle, detectable throughout the Universe. In particular, a binary with rest-frame mass ≳10^{10}M_{⊙} can be detected by current timing arrays at arbitrarily high redshifts. The same claim will apply for less massive binaries with more sensitive future arrays. As a consequence, future searches for nanohertz gravitational waves could be expanded to target evolving high-redshift binaries. We calculate the maximum distance at which binaries can be observed with pulsar timing arrays and other detectors, properly accounting for redshift and using realistic binary waveforms. PMID:27015470

  10. Twin Binaries: Studies of Stability, Mass Transfer, and Coalescence

    CERN Document Server

    Lombardi, James C; Dooley, Katherine L; Gearity, Kyle; Kalogera, Vassiliki; Rasio, Frederic A

    2010-01-01

    Motivated by suggestions that binaries with almost equal-mass components ("twins") play an important role in the formation of double neutron stars and may be rather abundant among binaries, we study the stability of synchronized close and contact binaries with identical components in circular orbits. In particular, we investigate the dependency of the innermost stable circular orbit on the core mass, and we study the coalescence of the binary that occurs at smaller separations. For twin binaries composed of convective main-sequence stars, subgiants, or giants with low mass cores (M_c ~0.15M), we find that stable contact configurations exist at all separations down to the Roche limit, when mass shedding through the outer Lagrangian points triggers a coalescence of the envelopes and leaves the cores orbiting in a central tight binary. We discuss the implications of our results to the formation of binary neutron stars.

  11. Template Mode Hierarchies for Binary Black Hole Mergers

    CERN Document Server

    Healy, James; Pekowsky, Larne; Shoemaker, Deirdre

    2013-01-01

    Matched filtering is a popular data analysis framework used to search for gravitational wave signals emitted by compact object binaries. The templates used in matched filtering searches are constructed predominantly from the quadrupolar mode because this mode is the energetically most dominant channel. However, for highly precessing binaries or binaries with moderately large mass ratios, significant power is also carried by higher-order modes. We investigate how the inclusion of higher modes in the templates increases the prospects for detecting gravitational waves. Specifically, we use numerical relativity waveforms from the late inspiral and coalescence of binary black holes to identify mode hierarchies that cover the sky of binary orientations. We show that the ordering in these hierarchies depends on the characteristics of the binary system and the mode strengths. Our study demonstrates that detecting moderately high precessing or unequal mass binaries requires the inclusion of higher modes in the templat...

  12. Performance analysis and binary working fluid selection of combined flash-binary geothermal cycle

    International Nuclear Information System (INIS)

    Performance of the combined flash-binary geothermal power cycle for geofluid temperatures between 150 and 250 °C is studied. A thermodynamic model is developed, and the suitable binary working fluids for different geofluid temperatures are identified from a list of thirty working fluid candidates, consisting environmental friendly refrigerants and hydrocarbons. The overall system exergy destruction and Vapor Expansion Ratio across the binary cycle turbine are selected as key performance indicators. The results show that for low-temperature heat sources using refrigerants as binary working fluids result in higher overall cycle efficiency and for medium and high-temperature resources, hydrocarbons are more suitable. For combined flash-binary cycle, secondary working fluids; R-152a, Butane and Cis-butane show the best performances at geofluid temperatures 150, 200 and 250 °C respectively. The overall second law efficiency is calculated as high as 0.48, 0.55 and 0.58 for geofluid temperatures equal 150, 200 and 250 °C respectively. The flash separator pressure found to has important effects on cycle operation and performance. Separator pressure dictates the work production share of steam and binary parts of the system. And there is an optimal separator pressure at which overall exergy destruction of the cycle achieves its minimum value. - Highlights: • Performance of the combined flash-binary geothermal cycle is investigated. • Thirty different fluids are screened to find the most suitable ORC working fluid. • Optimum cycle operation conditions presented for geofluids between 150 °C and 250 °C. • Refrigerants are more suitable for the ORC at geothermal sources temperature ≤200 °C. • Hydrocarbons are more suitable for the ORC at geothermal sources temperature >200 °C

  13. [Modified Gedelisa test (electrophoresis in gradient of polyacrylamide gel combined with Elisa test). Applications to Toxoplasma gondii exo-antigens (author's transl)].

    Science.gov (United States)

    Desgeorges, P T; Ambroise-Thomas, P; Falanga, P; Renversez, J C

    1980-01-01

    The authors describe a modified Gedelisa test made up an electrophorese in gradient polyacrylamide gel plus an Elisa test. The gel gradient, after electrophoretic migration is cut longitudinaly. One half is stained with Coomassie blue and the second half is cut in slices of 1 mm thick. Each slice is placed in a well of a microtitration polystirene plate, filled up with carbonate buffer pH 9,6 and then scrached. Proteins diffuse out of the gel and coated on the polystirene. The antigenicity of the coated proteins is revealed by Elisa test. This technique was applied to the study of Toxoplasma gondii exo-antigens obtained from medium of in vitro culture on Vero cells. This antigen contains four fractions, three of them are stained with Coomassie blue, their molecular weights are 160 000, 830 000 and more than one million daltons. PMID:7212392

  14. Probing the MSP prenatal stage: the optical identification of the X-ray burster EXO 1745-248 in Terzan 5

    CERN Document Server

    Ferraro, F R; Lanzoni, B; Cadelano, M; Massari, D; Dalessandro, E; Mucciarelli, A; -,

    2015-01-01

    We report on the optical identification of the neutron star burster EXO 1745-248 in Terzan 5. The identification was performed by exploiting HST/ACS images acquired in Director's Discretionary Time shortly after (approximately 1 month) the Swift detection of the X-ray burst. The comparison between these images and previous archival data revealed the presence of a star that currently brightened by ~3 magnitudes, consistent with expectations during an X-ray outburst. The centroid of this object well agrees with the position, in the archival images, of a star located in the Turn-Off/Sub Giant Branch region of Terzan 5. This supports the scenario that the companion should has recently filled its Roche Lobe. Such a system represents the pre-natal stage of a millisecond pulsar, an evolutionary phase during which heavy mass accretion on the compact object occurs, thus producing X-ray outbursts and re-accelerating the neutron star.

  15. News and Views: NASA puts JWST back on track, but ExoMars collaboration looks unlikely; Marsquakes happening yesterday, geologically; UFOs from black holes control shape of galaxies

    Science.gov (United States)

    2012-04-01

    NASA's funding plans put the James Webb Space Telescope firmly on track for a launch in 2018, to widespread relief, but the essentially flat funding settlement for 2013 overall means something has to go. Planetary science seems hardest hit, with the especial blow for European planetary scientists of NASA pulling out of ExoMars, the ESA-led mission to look for signs of life on Mars. Images from the High Resolution Imaging Science Experiment have shown boulders displaced by seismic activity on Mars in the past few million years, and possibly much more recently than that. The bigger the supermassive black hole at the centre of a galaxy, the faster the stars in the galactic bulge rotate. Why this should be so has been something of a puzzle, but now a mechanism that is both powerful and common enough to do the job has been identified.

  16. Plasma turbulence disc circulating the equatorial region of the plasmasphere identified by the plasma wave detector (PWS) onboard the akebono (EXOS-D) satellite

    International Nuclear Information System (INIS)

    For the observation data of the plasma wave turbulence detected by the PWS(Plasma Wave and Sounder Experiment) on board the EXOS-D (Akebono) satellite, the enhancements of the upper hybrid wave emission called equatorial enhancement of the plasma wave turbulence (EPWAT) that are characterized by the increasing level of the upper hybrid emissions are studied on their occurrence regions and occurrence conditions. The results show that EPWAT's encircle the magnetic equator forming a disc region that spreads from 1,000k to 10,000km altitude without dependence on the local time. The generation of plasma wave turbulences, EPWAT's are possibly controlled by the plasma drift as principal source in the region of the magnetic equator due to existing electric field

  17. Observations of the transient X-ray pulsar EXO 053109-6609.2 with ASCA, BeppoSAX and XMM-Newton

    International Nuclear Information System (INIS)

    We report timing and spectral properties of the transient X-ray pulsar EXO 053109-6609.2 using observations carried out with ASCA, BeppoSAX, and XMM-Newton observatories. Pulse period measurements of the source show a monotonic spin-up trend since 1996. The pulse profile is found to have a strong luminosity dependence, a single peaked profile at low luminosity that changes to a double peaked profile at high luminosity. The X-ray spectrum is described by a simple power-law model with photon index in the range of 0.2-0.8. A soft excess over the power-law continuum is also detected from XMM-Newton observation

  18. Crystallization and preliminary X-ray crystallographic study on a xyloglucan-specific exo-beta-glycosidase, oligoxyloglucan reducing-end specific cellobiohydrolase.

    Science.gov (United States)

    Yaoi, Katsuro; Kondo, Hidemasa; Suzuki, Mamoru; Noro, Natsuko; Tsuda, Sakae; Mitsuishi, Yasushi

    2003-10-01

    A novel xyloglucan-specific exo-beta-glycosidase, oligoxyloglucan reducing-end specific cellobiohydrolase (OXG-RCBH), recognizes the reducing end of oligoxyloglucan and releases two glucosyl residue segments from the main chain. OXG-RCBH was crystallized by the hanging-drop vapour-diffusion method with polyethylene glycol 3000 and polyethylene glycol 400 as precipitants. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 61.0, b = 146.9, c = 211.9 A. The crystals diffract to a resolution of 2.2 A and are suitable for X-ray structure analysis. PMID:14501131

  19. Phenomenological gravitational waveforms from spinning coalescing binaries

    CERN Document Server

    Sturani, R; Cadonati, L; Guidi, G M; Healy, J; Shoemaker, D; Vicere', A

    2010-01-01

    An accurate knowledge of the coalescing binary gravitational waveform is crucial for match filtering techniques, which are currently used in the observational searches performed by the LIGO-Virgo collaboration. Following an earlier paper by the same authors we expose the construction of analytical phenomenological waveforms describing the signal sourced by generically spinning binary systems. The gap between the initial inspiral part of the waveform, described by spin-Taylor approximants, and its final ring-down part, described by damped exponentials, is bridged by a phenomenological phase calibrated by comparison with the dominant spherical harmonic mode of a set of waveforms including both numerical and phenomenological waveforms of a different type. All waveforms considered describe equal mass systems with dimension-less spin magnitudes equal to 0.6. The noise-weighted overlap integral between numerical and phenomenological waveforms ranges between 0.93 and 0.98 for a wide span of mass values.

  20. Spin-Spin Coupling in Asteroidal Binaries

    Science.gov (United States)

    Batygin, Konstantin; Morbidelli, Alessandro

    2015-11-01

    Gravitationally bound binaries constitute a substantial fraction of the small body population of the solar system, and characterization of their rotational states is instrumental to understanding their formation and dynamical evolution. Unlike planets, numerous small bodies can maintain a perpetual aspheroidal shape, giving rise to a richer array of non-trivial gravitational dynamics. In this work, we explore the rotational evolution of triaxial satellites that orbit permanently deformed central objects, with specific emphasis on quadrupole-quadrupole interactions. Our analysis shows that in addition to conventional spin-orbit resonances, both prograde and retrograde spin-spin resonances naturally arise for closely orbiting, highly deformed bodies. Application of our results to the illustrative examples of (87) Sylvia and (216) Kleopatra multi-asteroid systems implies capture probabilities slightly below ~10% for leading-order spin-spin resonances. Cumulatively, our results suggest that spin-spin coupling may be consequential for highly elongated, tightly orbiting binary objects.