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  1. AO Camelopardalis

    NASA Astrophysics Data System (ADS)

    Milone, E. F.; Piggott, D. H.; Morris, S. L.

    1982-04-01

    The first UBV light curves of the system AO Cam are presented, and reveal a W UMa light curve with a period of 0.329917 days. Fourier coefficients for the full B and V light curves were used to place approximate empirical limits on the 75-80 deg inclination, fill-out parameter of approximately 0.8, and mass-ratio in the 0.7-0.8 range, following the methods of Rucinski (1973, 1974). The spectral type of the system is about G5.

  2. Retinal AO OCT

    NASA Astrophysics Data System (ADS)

    Zawadzki, Robert J.; Miller, Donald T.

    The last two decades have witnessed extraordinary advances in optical technology to image noninvasively and at high resolution the posterior segment of the eye. Two of the most impactful technological advancements over this period have arguably been optical coherence tomography (OCT) and adaptive optics (AO). The strengths of these technologies complement each other and when combined have been shown to provide unprecedented, micron-scale resolution (<3 μm) in all three dimensions and sensitivity to image the cellular retina in the living eye. This powerful extension of OCT, that is AO-OCT, is the focus of this chapter. It presents key aspects of designing and implementing AO-OCT systems. Particular attention is devoted to the relevant optical properties of the eye that ultimately define these systems, AO componentry and operation tailored for ophthalmic use, and of course use of the latest technologies and methods in OCT for ocular imaging. It surveys the wide range of AO-OCT designs that have been developed for retinal imaging, with AO integrated into every major OCT design configuration. Finally, it reviews the scientific and clinical studies reported to date that show the exciting potential of AO-OCT to image the microscopic retina and fundus in ways not previously possible with other noninvasive methods and a look to future developments in this rapidly growing field.

  3. AO Group Annual Report

    SciTech Connect

    Olivier, S

    2005-10-04

    The Adaptive Optics (AO) Group in I Division develops and tests a broad range of advanced wavefront control technologies. Current applications focus on: Remote sensing, High power lasers, Astronomy, and Human vision. In the area of remote sensing, the AO Group leads a collaborative effort with LLNL's Nonproliferation, Arms Control & International Security (NAI) Directorate on Enhanced Surveillance Imaging. The ability to detect and identify individual people or vehicles from long-range is an important requirement for proliferation detection and homeland security. High-resolution imaging along horizontal paths through the atmosphere is limited by turbulence, which blurs and distorts the image. For ranges over {approx}one km, visible image resolution can be reduced by over an order of magnitude. We have developed an approach based on speckle imaging that can correct the turbulence-induced blurring and provide high resolution imagery. The system records a series of short exposure images which freeze the atmospheric effects. We can then estimate the image magnitude and phase using a bispectral estimation algorithm which cancels the atmospheric effects while maintaining object information at the diffraction limit of the imaging system.

  4. Descoberta de um aglomerado estelar massivo associado a fonte IRAS 16177-5018

    NASA Astrophysics Data System (ADS)

    Roman Lopes, A.; Abraham, Z.; Lépine, J. R. D.

    2003-08-01

    Neste trabalho apresentamos a descoberta de um aglomerado de estrelas jovens e massivas embebido em uma região HII extensa associado com a fonte IRAS 16177-5018, que se apresenta invisível na faixa óptica do espectro eletromagnético, onde a extinção é da ordem de AV = 26 magnitudes. As observações foram feitas com a camera infravermelha (CamIV) do Laboratório Nacional de Astrofísica, Brasil, equipada com um detector Hawaii de HgCdTe de 1024´1024 pixel acoplada ao telescópio de 60 cm Boller & Chivens do IAG. A fotometria obtida a partir das imagens nas bandas J, H e K (filtro estreito) mostrou a presença de fontes com excesso de emissão no infravermelho em 2.2 mm, concentradas em uma área de aproximadamente um minuto de arco quadrado em torno da nebulosa na qual esta embebido o objeto identificado como a fonte IRAS. A fonte IRAS apresenta um índice espectral (entre 2.2 21.3 mm) a = d log(l Fl) / d log l = 4.78, característico de um objeto extremamente jovem com luminosidade bolométrica (obtida da integral da densidade de fluxo entre o infravermelho próximo (1.25mm) e o infravermelho distante (100mm)) de 2.8´105L¤, o qual corresponde a uma estrela da sequência principal de idade zero de cerca de 42 M¤. A partir do diagrama cor-magnitude foi possível classificar a maioria dos membros do aglomerado como estrelas massivas mais luminosas que tipo espectral B5.

  5. MEMS AO for Planet Finding

    NASA Technical Reports Server (NTRS)

    Rao, Shanti; Wallace, J. Kent; Shao, Mike; Schmidtlin, Edouard; Levine, B. Martin; Samuele, Rocco; Lane, Benjamin; Chakrabarti, Supriya; Cook, Timothy; Hicks, Brian; Jung, Paul

    2008-01-01

    This slide presentation reviews a method for planet finding using microelectromechanical systems (MEMS) Adaptive Optics (AO). The use of a deformable mirror (DM) is described as a part of the instrument that was designed with a nulling interferometer. The strategy that is used is described in detail.

  6. Aperture masking behind AO systems

    NASA Astrophysics Data System (ADS)

    Ireland, Michael J.

    2012-07-01

    Sparse Aperture-Mask Interferometry (SAM or NRM) behind Adaptive Optics (AO) has now come of age, with more than a dozen astronomy papers published from several 5-10m class telescopes around the world. I will describe the reasons behind its success in achieving relatively high contrasts ( 1000:1 at lambda/ D) and repeatable binary astronomy at the diffraction limit, even when used behind laser-guide star adaptive optics. Placed within the context of AO calibration, the information in an image can be split into pupil-plane phase, Fourier amplitude and closure-phase. It is the closure-phase observable, or its generalisation to Kernel phase, that is immune to pupil-plane phase errors at first and second-order and has been the reason for the technique's success. I will outline the limitations of the technique and the prospects for aperture-masking and related techniques in the future.

  7. Cometas: Das Lendas aos Fatos

    NASA Astrophysics Data System (ADS)

    Voelzke, M. R.

    O descobrimento de cometas, devido ao seu aparecimento espetacular, tem registro nas mais antigas culturas humanas. A primeira referência situa-se no ano de 1095 antes de Cristo [a.C.; HO; HO, 1962]. A quantidade de registros de descobrimentos cometários, principalmente provenientes do território chinês em particular e do oriente em geral, aumentou gradualmente a partir do quarto século depois de Cristo (d.C.). É de origem chinesa a primeira referência ao cometa P/Halley no ano de 240 a.C. [VOELZKE, 1993]. Com o desenvolvimento da astronomia relativamente às técnicas observacionais os descobrimentos bem como as observações cometárias aumentaram sensivelmente a partir do século XVII, sendo que a partir do século XIX um novo incremento ocorreu devido ao emprego da fotografia e a resultante melhora de sensibilidade na observação.

  8. Aerosol Observing System (AOS) Handbook

    SciTech Connect

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  9. The triple system AO Monocerotis

    NASA Astrophysics Data System (ADS)

    Wolf, M.; Kučáková, H.; Hynek, T.; Melcer, L. Å.

    2010-05-01

    The variable star AO Mon is a relatively bright but seldom investigated early-type eccentric eclipsing binary. Thirty new eclipses were measured as a part of our long-term observational project or derived from previous measurements. Based on a new solution of the current O-C diagram, we found for the first time a rapid apsidal advance superimposed with a light-time effect caused by a third unseen body in the system. Their short periods are 33.8 years and 3.6 years for the apsidal motion and the third-body circular orbit, respectively. The observed internal structure constant was derived to be log k2, obs = -2.23, which is close to the theoretically expected value. The relativistic as well as the third-body effects on the apsidal advance are negligible, as they are only about 3% of the total apsidal motion rate. Partly based on observations secured at the South African Astronomical Observatory, Sutherland, South Africa, in April 2004.

  10. The Magellan Telescope adaptive secondary AO system

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Gasho, Victor; Kopon, Derek; Hinz, Phil M.; Hoffmann, William F.; Uomoto, Alan; Hare, Tyson

    2008-07-01

    The Magellan Clay telescope is a 6.5m Gregorian telescope located in southern Chile at Las Campanas Observatory. The Gregorian design allows for an adaptive secondary mirror that can be tested off-sky in a straight-forward manner. We have fabricated a 85 cm diameter aspheric adaptive secondary with our subcontractors and partners. This secondary has 585 actuators with <1 msec response times. The chopping adaptive secondary will allow low emissivity AO science. We will achieve very high Strehls (~98%) in the Mid-IR AO (8-26 microns) with the BLINC/MIRAC4 Mid-IR science camera. This will allow the first "super-resolution" and nulling Mid-IR studies of dusty southern objects. We will employ a high order (585 mode) pyramid wavefront sensor similar to that used in the Large Binocular Telescope AO systems. The relatively high actuator count will allow modest Strehls to be obtained in the visible (~0.8μm). Our visible light AO (Vis AO) science camera is fed by an advanced ADC and beamsplitter piggy-backed on the WFS optical table. The system science and performance requirements, and an overview the design, interface and schedule for the Magellan AO system are presented here.

  11. Into the blue: AO science with MagAO in the visible

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Males, Jared R.; Follette, Katherine B.; Hinz, Phil; Morzinski, Katie; Wu, Ya-Lin; Kopon, Derek; Riccardi, Armando; Esposito, Simone; Puglisi, Alfio; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Quiros-Pacheco, Fernando

    2014-08-01

    We review astronomical results in the visible (λ<1μm) with adaptive optics. Other than a brief period in the early 1990s, there has been little astronomical science done in the visible with AO until recently. The most productive visible AO system to date is our 6.5m Magellan telescope AO system (MagAO). MagAO is an advanced Adaptive Secondary system at the Magellan 6.5m in Chile. This secondary has 585 actuators with < 1 msec response times (0.7 ms typically). We use a pyramid wavefront sensor. The relatively small actuator pitch (~23 cm/subap) allows moderate Strehls to be obtained in the visible (0.63-1.05 microns). We use a CCD AO science camera called "VisAO". On-sky long exposures (60s) achieve <30mas resolutions, 30% Strehls at 0.62 microns (r') with the VisAO camera in 0.5" seeing with bright R < 8 mag stars. These relatively high visible wavelength Strehls are made possible by our powerful combination of a next generation ASM and a Pyramid WFS with 378 controlled modes and 1000 Hz loop frequency. We'll review the key steps to having good performance in the visible and review the exciting new AO visible science opportunities and refereed publications in both broad-band (r,i,z,Y) and at Halpha for exoplanets, protoplanetary disks, young stars, and emission line jets. These examples highlight the power of visible AO to probe circumstellar regions/spatial resolutions that would otherwise require much larger diameter telescopes with classical infrared AO cameras.

  12. Characterization of an AO-OCT system

    SciTech Connect

    Evans, J W; Zawadzki, R J; Jones, S; Olivier, S; Werner, J S

    2007-07-26

    Adaptive optics (AO) and optical coherence tomography (OCT) are powerful imaging modalities that, when combined, can provide high-volumetric-resolution, images of the retina. The AO-OCT system at UC Davis has been under development for 2 years and has demonstrated the utility of this technology for microscopic, volumetric, in vivo retinal imaging [1]. The current system uses an AOptix bimorph deformable mirror (DM) for low-order, high-stroke correction [2] and a 140-actuator Boston Micromachines DM for high-order correction [3]. We are beginning to investigate the potential for increasing the image contrast in this system using higher-order wavefront correction. The first step in this analysis is to quantify the residual wavefront error (WFE) in the current system. Developing an error budget is a common tool for improved performance and system design in astronomical AO systems [4, 5]. The process for vision science systems is also discussed in several texts e.g. [6], but results from this type of analysis have rarely been included in journal articles on AO for vision science. Careful characterization of the AO system will lead to improved performance and inform the design of a future high-contrast system. In general, an AO system error budget must include an analysis of three categories of residual WFE: errors in measuring the phase, errors caused by limitations of the DM(s), and errors introduced by temporal variation. Understanding the mechanisms and relative size of these errors is critical to improving system performance. In this paper we discuss the techniques for characterizing these error sources in the AO-OCT system. It is useful to first calculate an error budget for the simpler case using a model eye, and then add the additional errors introduced for the case of a human subject. Measurement error includes calibration error, wavefront sensor (WFS) CCD noise, and sampling errors. Calibration errors must be measured by an external system. Typically this

  13. The Subaru Coronagraphic Extreme AO Project

    NASA Astrophysics Data System (ADS)

    Martinache, Frantz; Guyon, O.; Lozi, J.; Tamura, M.; Hodapp, K.; Suzuki, R.; Hayano, Y.; McElwain, M. W.

    2009-01-01

    While the existence of large numbers of extrasolar planets around solar type stars has been unambiguously demonstrated by radial velocity, transit and microlensing surveys, attempts at direct imaging with AO-equipped large telescopes remain unsuccessful. Because they supposedly offer more favorable contrast ratios, young systems consitute prime targets for imaging. Such observations will provide key insights on the formation and early evolution of planets and disks. Current surveys are limited by modest AO performance which limits inner working angle to 0.2", and only reach maximum sensitivity outside 1". This translates into orbital distances greater than 10 AU even on most nearby systems, while only 5 % of the known exoplanets have a semimajor axis greater than 10 AU. This calls for a major change of approach in the techniques used for direct imaging of the direct vicinity of stars. A sensible way to do the job is to combine coronagraphy and Extreme AO. Only accurate and fast control of the wavefront will permit the detection of high contrast planetary companions within 10 AU. The SCExAO system, currently under assembly, is an upgrade of the HiCIAO coronagraphic differential imaging camera, mounted behind the 188-actuator curvature AO system on Subaru Telescope. This platform includes a 1000-actuator MEMS deformable mirror for high accuracy wavefront correction and a PIAA coronagraph which delivers high contrast at 0.05" from the star (5 AU at 100 pc). Key technologies have been validated in the laboratory: high performance wavefront sensing schemes, spider vanes and central obstruction removal, and lossless beam apodization. The project is designed to be highly flexible to continuously integrate new technologies with high scientific payoff. Planned upgrades include an integral field unit for spectral characterization of planets/disks and a non-redundant aperture mask to push the performance of the system toward separations less than lambda/D.

  14. Experimental comparison of Wide Field AO control schemes using the Homer AO bench.

    NASA Astrophysics Data System (ADS)

    Parisot, Amélie; Petit, Cyril; Fusco, Thierry

    2011-09-01

    Wide Field Adaptive Optics (WFAO) concepts, such as Laser Tomography AO (LTAO) or Multi-Conjugate AO (MCAO) have been developed in order to overcome the anisoplanatism limit of classical AO. Most of the future AO-assisted instruments of ELTs rely on such concepts which have raised critical challenges such as tomographic estimation and from laser and natural guide star combined with efficient DM(s) control. In that context, the experimental validation of the various clever control solutions proposed by several teams in the past years is now essential to reach a level of maturity compatible with their implementation in future WFAO developments for ELT. The ONERA wide field AO facility (HOMER bench) has been developed for these very issues. Gathering a 3D turbulence generator, laser and natural guide stars, two deformable mirrors with variable altitude positions and a PC-based flexible and user-friendly RTC , HOMER allows the implementation and comparison of control schemes from the simplest least-square to the optimal Linear Quadratic Gaussian solutions including Virtual DM and Pseudo-closed loop approaches. After a description of the bench internal calibrations and ultimate performance, all the control schemes are compared experimentally. Their evolutions as a function of wavefront sensors SNR as well as their robustness to calibration / model errors are particularly emphasised. Finally, we derive from the previous works some specific calibrations and identifications procedures ensuring both robustness and efficiency of WFAO systems and we extrapolate their applications to the future ELT AO systems.

  15. MEMS DM development at Iris AO, Inc.

    NASA Astrophysics Data System (ADS)

    Helmbrecht, Michael A.; He, Min; Kempf, Carl J.; Besse, Marc

    2011-03-01

    Iris AO is actively developing piston-tip-tilt (PTT) segmented MEMS deformable mirrors (DM) and adaptive optics (AO) controllers for these DMs. This paper discusses ongoing research at Iris AO that has advanced the state-of-the-art of these devices and systems over the past year. Improvements made to open-loop operation and mirror fabrication enables mirrors to open-loop flatten to 4 nm rms. Additional testing of an anti snap-in technology was conducted and demonstrates that the technology can withstand 100 million snap-in events without failure. Deformable mirrors with dielectric coatings are shown that are capable of handling 630 W/cm2 of incident laser power. Over a localized region on the segment, the dielectric coatings can withstand 100kW/cm2 incident laser power for 30 minutes. Results from the first-ever batch of PTT489 DMs that were shipped to pilot customers are reported. Optimizations made to the open-loop PTT controller are shown to have latencies of 157.5 μs and synchronous array update rates of nearly 6.5 kHz. Finally, plans for the design and fabrication of the next-generation PTT939 DM are presented.

  16. Into the Blue: AO Science in the Visible with MagAO

    NASA Astrophysics Data System (ADS)

    Close, Laird; Males, Jared; Morzinski, Katie; Kopon, Derek; Follette, Kate; Rodigas, Timothy; Hinz, Philip; Wu, Ya-Lin; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Uomoto, Alan; Hare, Tison

    2013-12-01

    The Magellan Clay telescope is a 6.5m Gregorian telescope located in Chile at Las Campanas Observatory. We have fabricated an 85 cm diameter aspheric adaptive secondary with our subcontractors and partners, MagAO passed acceptance tests in spring 2012, and the entire System was commissioned from Nov 17 to Dec 7, 2012. This secondary has 585 actuators with < 1 msec response times (0.7 ms typically). We fabricated a high order (585 mode) pyramid wavefront sensor (similar to that of LBT's FLAO). The relatively high actuator count allows moderate Strehls to be obtained in the visible (0.63-1.05 microns). We have built an CCD science camera called "jVisAO". On-sky long exposures (60s) achieve 30% Strehls at 0.62 microns (r') with the VisAO camera in 0.5" seeing with bright R < 8 mag stars. These relatively high optical wavelength Strehls are made possible by our powerful combination of a next generation ASM and a Pyramid WFS with 200-400 controlled modes and 1000 Hz loop frequencies. To minimize non-common path errors and enable visible AO the VisAO science camera is fed by an advanced triplet ADC and is piggy-backed on the WFS optical board itself. Despite the ability to make 25 mas images we still have ~4 mas of resolution loss to residual vibrations. We will discuss what the most difficult aspects are for visible AO on ELTs scaling from our experience with MagAO.

  17. The first VisAO-fed integral field spectrograph: VisAO IFS

    NASA Astrophysics Data System (ADS)

    Follette, Katherine B.; Close, Laird M.; Kopon, Derek; Males, Jared R.; Gasho, Victor; Brutlag, Kevin M.; Uomoto, Alan

    2010-07-01

    We present the optomechanical design of the Magellan VisAO Integral Field Spectrograph (VisAO IFS), designed to take advantage of Magellan's AO system and its 85.1cm concave ellipsoidal Adaptive Secondary Mirror (ASM). With 585 actuators and an equal number of actively-controlled modes, this revolutionary second generation ASM will be the first to achieve moderate Strehl ratios into the visible wavelength regime. We have designed the VisAO IFS to be coupled to either Magellan's LDSS-3 spectrograph or to the planned facility M2FS fiber spectrograph and to optimize VisAO science. Designed for narrow field-of-view, high spatial resolution science, this lenslet-coupled fiberfed IFS will offer exciting opportunities for scientific advancement in a variety of fields, including protoplanetary disk morphology and chemistry, resolution and spectral classification of tight astrometric binaries, seasonal changes in the upper atmosphere of Titan, and a better understanding of the black hole M-sigma relation.

  18. Testing the VLT AO facility with ASSIST

    NASA Astrophysics Data System (ADS)

    Stuik, Remko; Arsenault, Robin; Boland, Wilfried; Deep, Atul; Delabre, Bernard; Hubin, Norbert; Kolb, Johann; La Penna, Paolo; Molster, Frank; Wiegers, Emiel

    2010-07-01

    The testing and verification of ESO Very Large Telescope Adaptive Optics Facility (VLT-AOF) requires new and innovative techniques to deal with the absence of an intermediate focus on the telescope. ASSIST, The Adaptive Secondary Setup and Instrument STimulator, was developed to provide a testing facility for the ESO AOF and will allow off-telescope testing of three elements of the VLT Adaptive Optics Facility; the Deformable Secondary Mirror (DSM) and the AO systems for MUSE and HAWK-I (GALACSI and GRAAL). ASSIST will provide a full testing environment which includes an interferometric testing mode for the DSM, an on-axis testing mode with a single wavefront sensor and full operation testing modes for both the AO systems. Both natural as well as laser guide stars will be simulated under various asterisms and a realistic turbulent atmosphere will be provided for varying atmospheric conditions. ASSIST passed its final design review and is now being manufactured, integrated and tested and will be operational in mid 2011, in time for first testing with the DSM.

  19. AO Observations of Three Powerful Radio Galaxies

    SciTech Connect

    de Vries, W; van Bruegel, W; Quirrenbach, A

    2002-08-01

    The host galaxies of powerful radio sources are ideal laboratories to study active galactic nuclei (AGN). The galaxies themselves are among the most massive systems in the universe, and are believed to harbor supermassive black holes (SMBH). If large galaxies are formed in a hierarchical way by multiple merger events, radio galaxies at low redshift represent the end-products of this process. However, it is not clear why some of these massive ellipticals have associated radio emission, while others do not. Both are thought to contain SMBHs, with masses proportional to the total luminous mass in the bulge. It either implies every SMBH has recurrent radio-loud phases, and the radio-quiet galaxies happen to be in the ''low'' state, or that the radio galaxy nuclei are physically different from radio-quiet ones, i.e. by having a more massive SMBH for a given bulge mass. Here we present the first results from our adaptive optics imaging and spectroscopy pilot program on three nearby powerful radio galaxies. Initiating a larger, more systematic AO survey of radio galaxies (preferentially with Laser Guide Star equipped AO systems) has the potential of furthering our understanding of the physical properties of radio sources, their triggering, and their subsequent evolution.

  20. Measuring Atmospheric Dynamics on Titan with AO

    NASA Astrophysics Data System (ADS)

    Adamkovics, Mate; de Pater, I.; Hartung, M.

    2009-05-01

    The cycling of fluid methane between Titan's atmosphere and surface, via seemingly familiar meteorological phenomena, is often compared to Earth's hydrology. Near-IR observations with AO resolve the moon's 1" disk, measure spatial variation in both the surface reflectivity and scattering in the atmosphere, and constrain the methane cycle. Forward models of the atmosphere are compared to observations and used to identify and quantify sources and altitudes of atmospheric opacity; including aerosols, clouds, and precipitation. The ubiquitous submicron aerosol hazes are tracers of global stratospheric dynamics over yearly timescales. Cloud properties may constrain the tropospheric circulation and are observed to change on hourly, daily, and seasonal timescales. Here we present observations of the daily life-cycle of a cloud system, a signature of tropospheric precipitation, seasonal changes in aerosol, and discuss the models that are used to quantify the observed meteorology.

  1. The Magellan Telescope Adaptive Secondary AO System: a visible and mid-IR AO facility

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Gasho, Victor; Kopon, Derek; Males, Jared; Follette, Katherine B.; Brutlag, Kevin; Uomoto, Alan; Hare, Tyson

    2010-07-01

    The Magellan Clay telescope is a 6.5m Gregorian telescope located in Chile at Las Campanas Observatory. The Gregorian design allows for an adaptive secondary mirror that can be tested off-sky in a straightforward manner. We have fabricated a 85 cm diameter aspheric adaptive secondary with our subcontractors and partners, the ASM passed acceptance tests in July 2010. This secondary has 585 actuators with <1 msec response times (0.7 ms typically). This adaptive secondary will allow low emissivity AO science. We will achieve very high Strehls (~98%) in the Mid-IR (3-26 microns) with the BLINC/MIRAC4 Mid-IR science camera. This will allow the first "super-resolution" and nulling Mid-IR studies of dusty southern objects. We will employ a high order (585 mode) pyramid wavefront sensor similar to that now successfully used at the Large Binocular Telescope. The relatively high actuator count will allow modest Strehls to be obtained in the visible (0.63-1.05 μm). Moderate (~20%) Strehls have already been obtained at 0.8 μm at the LBT with the same powerful combination of a next generation ASM and Pyramid WFS as we are providing for Magellan. Our visible light AO (VisAO) science camera is fed by an advanced triplet ADC and is piggy-backed on the WFS optical board. We have designed an additional "clean-up" very fast (2 kHz) tilt stabilization system for VisAO. Also a high-speed shutter will be used to block periods of poor correction. The VisAO facility can be reconfigured to feed an optical IFU spectrograph with 20 mas spaxels. The entire system passed CDR in June 2009, and is now finished the fabrication phase and is entering the integration phase. The system science and performance requirements, and an overview the design, interface and schedule for the Magellan AO system are presented here.

  2. LGS-AO Imaging of Every Kepler Planet Candidate: the Robo-AO KOI Survey

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Law, Nicholas; Morton, Timothy; Ziegler, Carl; Nofi, Larissa; Atkinson, Dani; Riddle, Reed

    2015-12-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging, to search for blended nearby stars which may be physically associated companions and/or responsible for transit false positives. We will present the results from searching for companions around over 3,000 Kepler planet hosts in 2012-2015. We will describe our first data release covering 715 planet candidate hosts, and give a preview of ongoing results including improved statistics on the likelihood of false positive planet detections in the Kepler dataset, many new planets in multiple star systems, and new exotic multiple star systems containing Kepler planets. We will also describe the automated Robo-AO survey data reduction methods, including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for extremely large adaptive optics surveys. Our first data release covered 715 objects, searching for companions from 0.15” to 2.5” separation with contrast up to 6 magnitudes. We measured the overall nearby-star-probability for Kepler planet candidates to be 7.4+/-1.0%, and we will detail the variations in this number with stellar host parameters. We will also discuss plans to extend the survey to other transiting planet missions such as K2 and TESS as Robo-AO is in the process of being re-deployed to the 2.1-m telescope at Kitt Peak for 3 years and a higher-contrast Robo-AO system is being developed for the 2.2-m UH telescope on Maunakea.

  3. Electromagnetic DM technology meets future AO demands

    NASA Astrophysics Data System (ADS)

    Hamelinck, Roger; Rosielle, Nick; Steinbuch, Maarten; Doelman, Niek

    New deformable mirror technology is developed by the Technische Universiteit Eindhoven, Delft University of Technology and TNO Science and Industry. Several prototype adaptive deformable mirrors are realized mirrors, up to 427 actuators and ∅150mm diameter, with characteristics suitable for future AO systems. The prototypes consist of a 100µm thick, continuous facesheet on which low voltage, electromagnetic, push-pull actuators impose out-of-plane displacements. The variable reluctance actuators with ±10µm stroke and nanometer resolution are located in a standard actuator module. Each module with 61 actuators connects to a single PCB with dedicated, 16 bit, PWM based, drivers. A LVDS multi-drop cable connects up to 32 actuator modules. With the actuator module, accompanying PCB and multi-drop system the deformable mirror technology is made modular in its mechanics and electronics. An Ethernet-LVDS bridge enables any commercial PC to control the mirror using the UDP standard. Latest results of the deformable mirror technology development are presented.

  4. Low-order AO system in LAMOST

    NASA Astrophysics Data System (ADS)

    Yuan, Xiangyan; Cui, Xiangqun; Liu, Genrong; Zhang, Yong; Qi, Yongjun

    2006-06-01

    The large sky area multi-object fiber spectroscopic telescope (LAMOST) is a special reflecting Schmidt telescope with its main optical axis on the meridian plane tilted by an angle of 25° to the horizontal. The clear aperture is 4m, working in optical band. The light path is 60m long when working in observing mode and it will be doubled if work in auto-collimation mode. So the image quality is affected clearly by the ground seeing and the dome seeing. In order to improve the seeing condition of the long light path, we enclosed the spherical primary and the focus unit in a tunnel enclosure and cooled the tunnel. This is an effective but passive method. Corresponding experiments and simulations show the main part of the aberrations caused by the ground seeing and dome seeing is slowly changed low order items such as tip-tilt, defocus, astigmatism, coma and spherical aberration. Thus we plan to develop the low-order AO system based on the low-cost 37-channel OKO deformable mirror for the telescope to better the ground seeing and the dome seeing, not aimed to reach diffraction limited image. This work is being carried on now.

  5. First closed-loop visible AO test results for the advanced adaptive secondary AO system for the Magellan Telescope: MagAO's performance and status

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Males, Jared R.; Kopon, Derek A.; Gasho, Victor; Follette, Katherine B.; Hinz, Phil; Morzinski, Katie; Uomoto, Alan; Hare, Tyson; Riccardi, Armando; Esposito, Simone; Puglisi, Alfio; Pinna, Enrico; Busoni, Lorenzo; Arcidiacono, Carmelo; Xompero, Marco; Briguglio, Runa; Quiros-Pacheco, Fernando; Argomedo, Javier

    2012-07-01

    The heart of the 6.5 Magellan AO system (MagAO) is a 585 actuator adaptive secondary mirror (ASM) with <1 msec response times (0.7 ms typically). This adaptive secondary will allow low emissivity and high-contrast AO science. We fabricated a high order (561 mode) pyramid wavefront sensor (similar to that now successfully used at the Large Binocular Telescope). The relatively high actuator count (and small projected ~23 cm pitch) allows moderate Strehls to be obtained by MagAO in the “visible” (0.63-1.05 μm). To take advantage of this we have fabricated an AO CCD science camera called "VisAO". Complete “end-to-end” closed-loop lab tests of MagAO achieve a solid, broad-band, 37% Strehl (122 nm rms) at 0.76 μm (i’) with the VisAO camera in 0.8” simulated seeing (13 cm ro at V) with fast 33 mph winds and a 40 m Lo locked on R=8 mag artificial star. These relatively high visible wavelength Strehls are enabled by our powerful combination of a next generation ASM and a Pyramid WFS with 400 controlled modes and 1000 Hz sample speeds (similar to that used successfully on-sky at the LBT). Currently only the VisAO science camera is used for lab testing of MagAO, but this high level of measured performance (122 nm rms) promises even higher Strehls with our IR science cameras. On bright (R=8 mag) stars we should achieve very high Strehls (>70% at H) in the IR with the existing MagAO Clio2 (λ=1-5.3 μm) science camera/coronagraph or even higher (~98% Strehl) the Mid-IR (8-26 microns) with the existing BLINC/MIRAC4 science camera in the future. To eliminate non-common path vibrations, dispersions, and optical errors the VisAO science camera is fed by a common path advanced triplet ADC and is piggy-backed on the Pyramid WFS optical board itself. Also a high-speed shutter can be used to block periods of poor correction. The entire system passed CDR in June 2009, and we finished the closed-loop system level testing phase in December 2011. Final system acceptance (

  6. AO 0235+164 and Surrounding Field: Surprising HST Results

    NASA Technical Reports Server (NTRS)

    Burbidge, E. M.; Beaver, E. A.; Cohen, Ross D.; Junkkarinen, V. T.; Lyons, R. W.

    1996-01-01

    Results obtained with the Hubble Space Telescope on the highly variable radio, x-ray, and gamma-ray emitting QSO (or BL Lac object) AO 0235 + 164 are presented and analyzed. WFPC2 images were obtained in 1994 June, when AO 0235 + 164 was bright (m approx. 17), and the results are described in Sec. 3. After subtraction of the PSF of the QSO, hereafter called AO following the nomenclature of Yanny et al. (1989), the companion object named A, 2 sec south of AO, is discovered not to be an elliptical galaxy as hypothesized earlier, but to be an AGN object, with a central UV-bright point-source nucleus and faint surrounding nebulosity extending to AO. The second companion object 1.3 sec east of AO discovered by Yanny et al. (1989) and named object Al, appears more like a normal spiral galaxy. We have measured the positions, luminosities, and colors of some 30 faint objects in the field around AO 0235 + 16; most are extended and may be star-forming galaxies in a loose group or cluster. Our most surprising result of the HST observations comes from FOS spectra obtained in 1995 July, discussed in Sec. 4. Because of a positioning error of the telescope and AO's faintness at that time (m approx. 20), object A was observed instead of the intended target AO. Serendipitously, we discovered A to have broad deep BALQSO-type absorptions of C IV, Si IV, N V shortward of broad emissions. A is thus ejecting high velocity, highly ionized gas into the surrounding IGM. We discuss in Sec. 5 the relationship of the objects in the central 10 sec X 1O sec region around AO, where redshifts z(sub e) = 0.94, z(sub a) = 0.524, 0.851 in AO, (sub e) = 0.524 and Z(sub BAL)=0.511 in A, are found. We hypothesize that some of the 30 faint objects in the 77 sec. x 77 sec. field may be part of a large star-forming region at z approx. 0.5, as suggested for a few objects by Yanny et al. (1989). The proximity of two highly active extragalactic objects, AO 0235+164 and its AGN companion A, is remarkable and

  7. The Subaru Coronagraphic Extreme AO Project: Progress and Upgrades

    NASA Astrophysics Data System (ADS)

    Jovanovic, Nemanja; Martinache, F.; Guyon, O.; Clergeon, C.; Garrel, V.

    2013-01-01

    The Subaru Coronagraphic Extreme AO (SCExAO) instrument consists of a high performance Phase Induced Amplitude Apodisation (PIAA) coronagraph combined with an extreme Adaptive Optics (AO) system operating in the near-infrared (H band). The extreme AO system driven by the 2000 element deformable mirror will allow for Strehl ratios>90% to be achieved in the H-band when it goes closed loop. This makes the SCExAO instrument a powerful platform for high contrast imaging down to angular separations of the order of 1 λ/D. In this paper we report on the recent progress in regards to the development of the instrument, which includes the addition of a visible bench that makes use of the light at shorter wavelengths not currently utilized by SCExAO and closing the loop on the tip/tilt wavefront sensor. We will also discuss two exciting guest instruments which will expand the capabilities of SCExAO over the next few years; namely CHARIS which is a integral field spectrograph as well as VAMPIRES, a visible aperture masking experiment based on polarimetric analysis of circumstellar disks.

  8. SCExAO: First Results and On-Sky Performance

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Guyon, Olivier; Martinache, Frantz; Clergeon, Christophe; McElwain, Michael; Thalmann, Christian; Jovanovic, Nemanja; Singh, Garima; Kudo, Tomoyuki

    2013-01-01

    We present new on-sky results for the Subaru Coronagraphic Extreme Adaptive Optics imager (SCExAO) verifying and quantifying the contrast gain enabled by key components: the closed-loop coronagraphic low-order wavefront sensor (CLOWFS) and focal plane wavefront control ("speckle nulling"). SCExAO will soon be coupled with a high-order, Pyramid wavefront sensor which will yield greater than 90% Strehl ratio and enable 10(exp 6) -10(exp 7) contrast at small angular separations allowing us to image gas giant planets at solar system scales. Upcoming instruments like VAMPIRES, FIRST, and CHARIS will expand SCExAO's science capabilities.

  9. SCExAO: First Results and On-Sky Performance

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Guyon, Olivier; Martinache, Frantz; Clergeon, Christophe; McElwain, Michael; Thalmann, Christian; Jovanovic, Nemanja; Singh, Garima; Kudo, Tomoyuki

    2014-01-01

    We present new on-sky results for the Subaru Coronagraphic Extreme Adaptive Optics imager (SCExAO) verifying and quantifying the contrast gain enabled by key components: the closed-loop coronagraphic low-order wavefront sensor (CLOWFS) and focal plane wavefront control (``speckle nulling''). SCExAO will soon be coupled with a high-order, Pyramid wavefront sensor which will yield > 90% Strehl ratio and enable 106-107 contrast at small angular separations allowing us to image gas giant planets at solar system scales. Upcoming instruments like VAMPIRES, FIRST, and CHARIS will expand SCExAO's science capabilities.

  10. Reproducibility of the Tronzo and AO classifications for transtrochanteric fractures☆

    PubMed Central

    Mattos, Carlos Augusto; Jesus, Alexandre Atsushi Koza; Floter, Michelle dos Santos; Nunes, Luccas Franco Bettencourt; Sanches, Bárbara de Baptista; Zabeu, José Luís Amim

    2015-01-01

    Objective To analyze the reproducibility of the Tronzo and AO classifications for transtrochanteric fractures. Method This was a cross-sectional study in which the intraobserver and interobserver concordance between two readings made by 11 observers was analyzed. The analysis of the variations used the kappa statistical method. Results Moderate concordance was found in relation to the AO classification, while slight concordance was found for the Tronzo classification. Conclusion This study found that the AO/Asif classification for transtrochanteric presented greater intra and interobserver reproducibility and that greater concordance was correlated with greater experience of the observers. Without division into subgroups, the AO/Asif classification was shown, as described in the literature, to be acceptable for clinical use in relation to transtrochanteric fractures of the femur, although it did not show absolute concordance, given that its concordance level was only moderate. Nonetheless, its concordance was better than that of the Tronzo classification. PMID:26535193

  11. LGS-AO Imaging of Every Kepler Planet Candidate: the Robo-AO KOI Survey

    NASA Astrophysics Data System (ADS)

    Law, Nicholas Michael; Baranec, Christoph; Morton, Timothy; Ziegler, Carl; Atkinson, Dani; Riddle, Reed

    2015-08-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging, to search for blended nearby stars which may be physically associated companions and/or responsible for transit false positives. We will present the results from searching for companions around over 3,000 Kepler planet hosts in 2012-2015. We will describe our first data release covering 715 planet candidate hosts, and give a preview of ongoing results including improved statistics on the likelihood of false positive planet detections in the Kepler dataset, many new planets in multiple star systems, and new exotic multiple star systems containing Kepler planets.We will also describe the automated Robo-AO survey data reduction methods, including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for extremely large adaptive optics surveys.Our first data release covered 715 objects, searching for companions from 0.15” to 2.5” separation with contrast up to 6 magnitudes. We measured the overall nearby-star-probability for Kepler planet candidates to be 7.4+/-1.0%, and we will detail the variations in this number with stellar host parameters. We will also discuss several KOIs of particular interest, including KOI-191 and KOI-1151, which are both multi-planet systems with detected stellar companions whose unusual planetary system architecture might be best explained if they are ``coincident multiple'' systems, with several transiting planets shared between the two stars. Finally, we will discuss and update the 98%-confidence evidence from our survey that third bodies in star/planet systems produce an excess of close-in giant planets.

  12. A Large-Telescope Natural Guide Star AO System

    NASA Technical Reports Server (NTRS)

    Redding, David; Milman, Mark; Needels, Laura

    1994-01-01

    None given. From overview and conclusion:Keck Telescope case study. Objectives-low cost, good sky coverage. Approach--natural guide star at 0.8um, correcting at 2.2um.Concl- Good performance is possible for Keck with natural guide star AO system (SR>0.2 to mag 17+).AO-optimized CCD should b every effective. Optimizing td is very effective.Spatial Coadding is not effective except perhaps at extreme low light levels.

  13. Beyond the Blur: Construction and Characterization of the First Autonomous AO System, and, An AO Survey of Magnetar Proper Motions

    NASA Astrophysics Data System (ADS)

    Tendulkar, Shriharsh Prakash

    Adaptive optics (AO) corrects distortions created by atmospheric turbulence and delivers diffraction-limited images on ground-based telescopes. The vastly improved spatial resolution and sensitivity has been utilized for studying everything from the magnetic fields of sunspots upto the internal dynamics of high-redshift galaxies. This thesis about AO science from small and large telescopes is divided into two parts: Robo-AO and magnetar kinematics. In the first part, I discuss the construction and performance of the world's first fully autonomous visible light AO system, Robo-AO, at the Palomar 60-inch telescope. Robo-AO operates extremely efficiently with an overhead < 50s, typically observing about 22 targets every hour. We have performed large AO programs observing a total of over 7,500 targets since May 2012. In the visible band, the images have a Strehl ratio of about 10% and achieve a contrast of upto 6 magnitudes at a separation of 1‧‧. The full-width at half maximum achieved is 110-130 milli-arcsecond. I describe how Robo-AO is used to constrain the evolutionary models of low-mass pre-main-sequence stars by measuring resolved spectral energy distributions of stellar multiples in the visible band, more than doubling the current sample. I conclude this part with a discussion of possible future improvements to the Robo-AO system. In the second part, I describe a study of magnetar kinematics using high-resolution near-infrared (NIR) AO imaging from the 10-meter Keck II telescope. Measuring the proper motions of five magnetars with a precision of upto 0.7 milli-arcsecond/yr -1, we have more than tripled the previously known sample of magnetar proper motions and proved that magnetar kinematics are equivalent to those of radio pulsars. We conclusively showed that SGR 1900+14 and SGR 1806-20 were ejected from the stellar clusters with which they were traditionally associated. The inferred kinematic ages of these two magnetars are 6 +/- 1.8 kyr and 650 +/-3 00

  14. Initial Performance of the Keck AO Wavefront Controller System

    SciTech Connect

    Johansson, E M; Acton, D S; An, J R; Avicola, K; Beeman, B V; Brase, J M; Carrano, C J; Gathright, J; Gavel, D T; Hurd, R L; Lai, O; Lupton, W; Macintosh, B A; Max, C E; Olivier, S S; Shelton, J C; Stomski, P J; Tsubota, K; Waltjen, K E; Watson, J A; Wizinowich, P L

    2001-03-01

    The wavefront controller for the Keck Observatory AO system consists of two separate real-time control loops: a tip-tilt control loop to remove tilt from the incoming wavefront, and a deformable mirror control loop to remove higher-order aberrations. In this paper, we describe these control loops and analyze their performance using diagnostic data acquired during the integration and testing of the AO system on the telescope. Disturbance rejection curves for the controllers are calculated from the experimental data and compared to theory. The residual wavefront errors due to control loop bandwidth are also calculated from the data, and possible improvements to the controller performance are discussed.

  15. High-Performance CCSDS AOS Protocol Implementation in FPGA

    NASA Technical Reports Server (NTRS)

    Clare, Loren P.; Torgerson, Jordan L.; Pang, Jackson

    2010-01-01

    The Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) space data link protocol provides a framing layer between channel coding such as LDPC (low-density parity-check) and higher-layer link multiplexing protocols such as CCSDS Encapsulation Service, which is described in the following article. Recent advancement in RF modem technology has allowed multi-megabit transmission over space links. With this increase in data rate, the CCSDS AOS protocol implementation needs to be optimized to both reduce energy consumption and operate at a high rate.

  16. Apple fruit copper amine oxidase isoforms: peroxisomal MdAO1 prefers diamines as substrates, whereas extracellular MdAO2 exclusively utilizes monoamines.

    PubMed

    Zarei, Adel; Trobacher, Christopher P; Cooke, Alison R; Meyers, Ashley J; Hall, J Christopher; Shelp, Barry J

    2015-01-01

    4-Aminobutyrate (GABA) accumulates in apple fruit during controlled atmosphere storage. A potential source of GABA is the polyamine putrescine, which can be oxidized via copper-containing amine oxidase (CuAO), resulting in the production 4-aminobutanal/Δ(1)-pyrroline, with the consumption of O2 and release of H2O2 and ammonia. Five putative CuAO genes (MdAO genes) were cloned from apple (Malus domestica Borkh. cv. Empire) fruit, and the deduced amino acid sequences found to contain the active sites typically conserved in CuAOs. Genes encoding two of these enzymes, MdAO1 and MdAO2, were highly expressed in apple fruit and selected for further analysis. Amino acid sequence analysis predicted the presence of a C-terminal peroxisomal targeting signal 1 tripeptide in MdAO1 and an N-terminal signal peptide and N-glycosylation site in MdAO2. Transient expression of green fluorescent fusion proteins in Arabidopsis protoplasts or onion epidermal cells revealed a peroxisomal localization for MdAO1 and an extracellular localization for MdAO2. The enzymatic activities of purified recombinant MdAO1 and MdAO2 were measured continuously as H2O2 production using a coupled reaction. MdAO1 did not use monoamines or polyamines and displayed high catalytic efficiency for 1,3-diaminopropane, putrescine and cadaverine, whereas MdAO2 exclusively utilized aliphatic and aromatic monoamines, including 2-phenylethylamine and tyramine. Together, these results indicate that MdAO1 may contribute to GABA production via putrescine oxidation in the peroxisome of apple fruit under controlled atmosphere conditions. MdAO2 seems to be involved in deamination of 2-phenylethylamine, which is a step in the biosynthesis of 2-phenylethanol, a contributor to fruit flavor and flower fragrance. PMID:25378687

  17. Holocene Evolution of Qing'ao Embayment, Southern China

    NASA Astrophysics Data System (ADS)

    Switzer, A. D.; Yu, F.; Chen, B.; Zheng, Z.; Wang, D.

    2012-12-01

    The Holocene evolution of the Qing'ao embayment, Nan'ao Island, southern China, is primarily the result of the interaction of tectonic activity, climate variation and changes in relative sea level. Characterizing the evolutionary history of the relatively small Qing'ao embayment during the Holocene will help improve our understanding of the driving mechanisms of coastal evolution in the area. To reconstruct the Holocene evolution history we analyzed the grain size, loss on ignition (LOI) and carbonate content of modern and core samples. Modern environmental analogs were examined in surface samples ranging from the coastal sand dunes through to offshore. The results of these modern samples suggest that dune sand (mean size of ~2.33Phi) are slightly finer than beach sand (mean size of 2.13Phi), and nearshore sediment is much coarser than offshore sediment (mean size of 5.90Phi). This modern analogs were then applied to 8 percussion cores from the Qing'ao embayment. A chronological framework obtained from 11 radiocarbon samples suggests that the embayment started to accept deposition since early Holocene, ~8500 cal. yr. BP. Three main phases of Holocene evolution were identified. A basin wide shell-rich sand sheet forms the basal Holocene facies and overlies clay rich presumably Pleistocene sediments or bedrock. This facies records an initial sedimentation phase associated with the early Holocene transgression into the embayment (~8500-6000 cal. yr. BP). The basal facies grades upward to a mixed sandy-mud facies which includes lagoonal clayey-silts, flood tide delta sands and records an estuarine phase lasting from ~6000-1000 cal. yr. BP that appears coincident with falling regional sea levels. Coincident with the estuarine phase is a period of coastal dune building recorded as yet undated massive sands that are found in the upper fill. Toward the end of the estuarine phase it is apparent that dune migration has restricted the lagoon entrance and that this was

  18. Diffraction limited operation with ARGOS: a hybrid AO system

    NASA Astrophysics Data System (ADS)

    Bonaglia, M.; Busoni, L.; Quirós-Pacheco, F.; Esposito, S.

    2010-07-01

    ARGOS, the Laser Guide Star (LGS) facility of the Large Binocular Telescope (LBT), implements a Ground Layer Adaptive Optics (GLAO) system, using 3 low-altitude beacons, to improve the resolution over the 4'×4' FoV of the imager and Multi Object Spectrograph (MOS) LUCIFER. In this paper we discuss the performance and the reconstruction scheme of an hybrid AO system using the ARGOS Rayleigh beacons complemented with a single faint high-altitude star (NGS or sodium beacon) to sense the turbulence of the upper atmosphere allowing an high degree of on-axis correction. With the ARGOS system, the NGS-upgrade can be immediately implemented at LBT using the already existing Pyramid WFS offering performance similar to the NGS AO system with the advantage of a larger sky coverage.

  19. High-Resolution Imaging of Asteroids/Satellites with AO

    NASA Astrophysics Data System (ADS)

    Merline, William

    2012-02-01

    We propose to make high-resolution observations of asteroids using AO, to measure size, shape, and pole position (spin vectors), and/or to search for satellites. We have demonstrated that AO imaging allows determination of the pole/dimensions in 1 or 2 nights on a single target, rather than the years of observations with lightcurve inversion techniques that only yield poles and axial ratios, not true dimensions. Our new technique (KOALA) combines AO imaging with lightcurve and occultation data for optimum size/shape determinations. We request that LGS be available for faint targets, but using NGS AO, we will measure several large and intermediate asteroids that are favorably placed in spring/summer of 2012 for size/shape/pole. Accurately determining the volume from the often-irregular shape allows us to derive densities to much greater precision in cases where the mass is known, e.g., from the presence of a satellite. We will search several d! ozen asteroids for the presence of satellites, particularly in under-studied populations, particularly NEOs (we have recently achieved the first-ever optical image of an NEO binary [Merline et al. 2008b, IAUC 8977]). Satellites provide a real-life lab for testing collisional models. We will search for satellites around special objects at the request of lightcurve observers, and we will make a search for debris in the vicinity of Pluto, in support of the New Horizons mission. Our shape/size work requires observations over most of a full rotation period (typically several hours).

  20. LDEF results for polymer matrix composite experiment AO 180

    NASA Technical Reports Server (NTRS)

    Tennyson, R. C.

    1992-01-01

    This report represents a summary of the results obtained to-date on a polymer matrix composite experiment (AO 180) located at station D-12, about 82 deg off the 'ram' direction. Different material systems comprised of graphite, boron, and aramid (Kevlar) fiber reinforcements were studied. Although previous results were presented on in-situ thermal-vacuum cycling effects, particularly dimensional changes associated with outgassing, additional comparative data will be shown from ground-based tests on control and flight samples. The system employed was fully automated for thermal-vacuum cycling using a laser interferometer for monitoring displacements. Erosion of all three classes of materials due to atomic oxygen (AO) will also be discussed, including angle of incidence effects. Data from this experiment will be compared to published results for similar materials in other LDEF experiments. Composite materials' erosion yields will be presented on an AO design nomogram useful for estimating total material loss for given exposure conditions in low Earth orbit (LEO). Optical properties of these materials will also be compared with control samples. A survey of the damage caused by micrometeoroids/debris impacts will be addressed as they relate to polymer matrix composites. Correlations between hole size and damage pattern will be given. Reference to a new nomogram for estimating the number distribution of micrometeoroid/debris impacts for a given space structure as a function of time in LEO will be addressed based on LDEF data.

  1. SIMS chemical and isotopic analysis of impact features from LDEF experiments AO187-1 and AO187-2

    NASA Technical Reports Server (NTRS)

    Stadermann, Frank J.; Amari, Sachiko; Foote, John; Swan, Pat; Walker, Robert M.; Zinner, Ernst

    1995-01-01

    Previous secondary ion mass spectrometry (SIMS) studies of extended impact features from LDEF capture cell experiment AO187-2 showed that it is possible to distinguish natural and man-made particle impacts based on the chemical composition of projectile residues. The same measurement technique has now been applied to specially prepared gold target impacts from experiment AO187-1 in order to identify the origins of projectiles that left deposits too thin to be analyzed by conventional energy-dispersive x-ray (EDX) spectroscopy. The results indicate that SIMS may be the method of choice for the analysis of impact deposits on a variety of sample surfaces. SIMS was also used to determine the isotopic compositions of impact residues from several natural projectiles. Within the precision of the measurements all analyzed residues show isotopically normal compositions.

  2. [Investigation on circulation of Ao shi shang han jin jing lu (Ao's Golden mirror of cold pathogenic diseases) in Japan].

    PubMed

    Liang, Rong

    2003-01-01

    Being the earliest extant work on tongue diagnostics, Ao shi jin jing lu was block-printed and published in 1654 after it was spread into Japan, on the basis of which many kinds of manuscripts were made. This book not only exerted profound influence on the Kampo diagnostics in Edo age, but also laid down a foundation for the formation of pulse diagnostic school of tongue diagnostics in Kampo medicine. PMID:12921588

  3. Identification of system misregistrations during AO-corrected observations

    NASA Astrophysics Data System (ADS)

    Béchet, C.; Thiébaut, É.; .; Tallon, M.; Kolb, J.; Madec, P.-Y.

    2011-09-01

    The E-ELT will be equipped with a deformable mirror inside the telescope. The performance of reconstruction and control depends on the calibration of the interaction matrix- or a model of the interaction matrix- , which characterizes the system and the relationship between the commands sent to the deformable mirrors (DM) and the wavefront sensors (WFS) slopes. Such a calibration will be more complex than for the current systems at the VLT since it will have to be at least partly measured on sky and for a much larger number of degrees of freedom (more than 5000). In addition, gravity or temperature variations for instance are likely to introduce slow evolution of the matching between the M4 Deformable mirror and the WFS geometry. This can occur during observations and therefore degrade the adaptive optics (AO) correction. To relax the need of frequent painful calibrations and to prevent a loss of performance due to misregistrations, we investigate how to track the evolution of the interaction matrix errors in closed-loop without introducing any degradation in the observations. This is done thanks to identification methods and optimization theory. First, we formally describe the problem and the difficulties of such an identification in closed-loop configuration. Then, we present 2 solutions, based on the optimization of the error of estimates of the WFS slopes, at the output of the closed-loop AO. The performance of the methods and their limitations are discussed formally and thanks to numerical simulations of a high order AO system. We finally explore to which extent these methods currently studied for the Adaptive Optics Facility (AOF) at the VLT can be applied to the E-ELT.

  4. Intramedullary locking femoral nails. Experience with the AO nail.

    PubMed Central

    Fogarty, A. B.; Yeates, H. A.

    1991-01-01

    The AO interlocking nail was introduced to the Ulster Hospital, Dundonald in 1988 and since then has been used in over 50 patients with femoral shaft fractures. We have reviewed 45 patients with 46 femoral shaft fractures treated between June 1988 and April 1990. These included four compound fractures and 13 comminuted fractures. The results compare favourably with other series. The union rate was 98% and there were no instances of deep infection. The alternative treatment methods available are discussed along with a review of the relevant literature. Images Fig 3 Fig 5 PMID:1785145

  5. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray C03

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray C03 The IDE mounting plate and the detector frames are coated with a brown stain similiar to that seen on the other experiments in this and other trays located nearby. The stain seems to be slightly darker along the lower edge of the solar sensor mounting plate. The colors and designs seen on the detectors are reflections of the surrounding area. The thin brown film on the detectors metallic surface has resulted in a duller reflection of a technician, in the upper left, and other items.

  6. Stream-Field Interactions in the Magnetic Accretor AO Piscium

    NASA Astrophysics Data System (ADS)

    Hellier, Coel; van Zyl, Liza

    2005-06-01

    UV spectra of the magnetic accretor AO Psc show absorption features for half the binary orbit. The absorption is unlike the wind-formed features often seen in similar stars. Instead, we attribute it to a fraction of the stream that overflows the impact with the accretion disk. Rapid velocity variations can be explained by changes in the trajectory of the stream depending on the orientation of the white dwarf's magnetic field. Hence, we are directly observing the interaction of an accretion stream with a rotating field. We compare this behavior to that seen in other intermediate polars and in SW Sex stars.

  7. Titanium alloys (AoN) and their involvement in osseointegration

    PubMed Central

    Danza, Matteo; Zollino, Ilaria; Candotto, Valentina; Cura, Francesca; Carinci, Francesco

    2012-01-01

    Background: Osseointegration is essential for a long-term successful and inflammation-free dental implant. Such a result depends on osteoblastic cells growth and differentiation at the tissue-implant interface. The aim of this study was to compare two different AoN titanium layers (GR4 and GR5) to investigate which one had a greater osteoconductive power using human osteoblasts (HOb) culture at two different time-points. Materials and Methods: The expression levels of some bone-related (ALPL, COL1A1, COL3A1, SPP1, RUNX2, and SPARC) were analyzed using real time reverse transcription-polymerase chain reaction (real time RT-PCR). Results: Real-time RT-PCR data showed that after 3 days of treatment with TiA4GR, the genes up-regulated were COL3A1, ALPL, SPP1, and RUNX2. Moreover, no difference in gene expression was noticed 4 days later. On the other hand, the genes that overexpressed after 3 days of treatment with AoN5GR were ALPL, SPP1, and RUNX2. In both cases, the expression of COL1A1 and SPARC was negatively regulated. Conclusion: Our data showed that both titanium surfaces led to osteoblasts recruitment, maturation, and differentiation, thus promoting osseointegration at the tissue-implant interface. PMID:23814585

  8. Robo-AO: autonomous and replicable laser-adaptive-optics and science system

    NASA Astrophysics Data System (ADS)

    Baranec, C.; Riddle, R.; Ramaprakash, A. N.; Law, N.; Tendulkar, S.; Kulkarni, S.; Dekany, R.; Bui, K.; Davis, J.; Burse, M.; Das, H.; Hildebrandt, S.; Punnadi, S.; Smith, R.

    2012-07-01

    We have created a new autonomous laser-guide-star adaptive-optics (AO) instrument on the 60-inch (1.5-m) telescope at Palomar Observatory called Robo-AO. The instrument enables diffraction-limited resolution observing in the visible and near-infrared with the ability to observe well over one-hundred targets per night due to its fully robotic operation. Robo-AO is being used for AO surveys of targets numbering in the thousands, rapid AO imaging of transient events and long-term AO monitoring not feasible on large diameter telescope systems. We have taken advantage of cost-effective advances in deformable mirror and laser technology while engineering Robo-AO with the intention of cloning the system for other few-meter class telescopes around the world.

  9. Searching and Studying Binary Asteroids with AO Systems

    NASA Astrophysics Data System (ADS)

    Marchis, F.; Descamps, P.; Berthier, J.; Hestroffer, D.; de Pater, I.; Conrad, A.; Le Mignant, D.; Chaffee, F.; Gavel, D.

    2003-05-01

    Our group has conducted adaptive optics observations of asteroids since 2001. Our main goal is the search and study of binary asteroids using several AO systems (Lick, Keck, VLT) and related technique such as Appulse (Berthier and Marchis, 2002) and Laser Guide Star observations (Marchis et al., AGU-EGS, 2003) to broaden the sample of asteroids observed from the main-belt out to the Kuiper Belt. We focussed our program last year on Trojan Asteroids. Six of them were observed using Appulses with Keck AO ( ˜0.05-0.10", mv=15.4-18.5), 6 with the LGS at Lick ( ˜0.25-0.35", mv<16) and 12 with the VLT/NACO system ( ˜0.10-0.14"; mv<16.7). None of these observations reveals the presence of a companion. Based on this sample, and including 617 Patroclus binary asteroid discovered by Merline et al. (IAU, 7741, 2001), we deduce that the proportion of binary Trojan asteroids larger than 40 km is less than 4%. We will promote and discuss a technique of the analysis of negative discovery in large samples. In January 2003, we conducted an observing campaign spanning 5 days of 121 Hermione with NACO, the new AO system offered at VLT. This C-type asteroid was discovered by Merline et al. (IAU, 7980, 2002). The companion, 6.1 mag fainter than the primary, is easily detected despite the faintness of the asteroid (mv ˜13). We use the method described in Marchis et al. (Icarus, 2003) to determine the orbit of the companion. Its orbital elements are a=794.7+/-2.1 km, and P=1.643+/-0.005 days. We derived a mass =1.47E19 kg, and a density of 3.1+/-0.8 g cm-3 (using IRAS diameter of 209+/-4.7 km). Considering typical densities of meteorite analogues (CI or CM carboneceous chondrite) would led to an extremely low macro-porosity of p<3%. This suggests that the volume of Hermione is ˜30% larger, which is also supported by our resolved images of this body. This work supported by the National Science Foundation Science and Technology Center for Adaptive Optics, based partly on observations

  10. Nao/ao Variability In The Coupled Bergen Climate Model

    NASA Astrophysics Data System (ADS)

    Sorteberg, A.; Furevik, T.; Bentsen, M.; Drange, H.; Kvamsto, N. G.; Thorstensen-Kindem, I.

    A new fully coupled atmosphere-ocean-sea ice model, known as the Bergen Climate Model (BCM), has been developed. The coupled model can be run with stretched co- ordinates both in the atmosphere and ocean and consists of the atmospheric model ARPEGE/IFS, and a global version of the isopycnal ocean model MICOM, including a sea ice model. The atmospheric model ARPEGE/IFS (c22) is a spectral model devel- oped jointly by Meteo-France and the European Centre for Medium-Range Weather Forecasts (ECMWF). The ocean circulation model is the Miami Isopycnic Coordinate Ocean Model (MI- COM). Several modifications have been done to the MICOM model including the incorporation of a thermodynamic and dynamic sea ice model, the use of tempera- ture as a prognostic variable instead of salinity, and the use of a metric scale factor in both lateral, so the model can easily be configured on a general orthogonal grid. Also,the thickness diffusion has been modified to better handle diffusion near bottom topography and the base of the mixed layer. Coupling has been done with the library OASIS where 14 different fields are ex- changed using Montecarlo mapping and subgrid interpolation. Continental runoff into the correct rivers and discharge into the correct ocean grid cells are performed using the Total Runoff Integrating Pathways (TRIP) data set. Results will be present from a 300 years flux adjusted control integration of BCM with todays climate, using a unstretched T63 truncation in the atmosphere and a 0.8 by 2.4 degree resolution (near the equator gradually transforming to approximate square grid cells towards the poles) in the ocean. The model output has been analysed for large scale variability in both the ocean and atmosphere, with emphasise on the North Atlantic and Arctic climate. Statistical properties of the NAO/AO signal, and its im- pacts on the climate components, are identified and compared with observations. The NAO/AO mode of variability show up in the model with

  11. LDEF (Flight), AO201 : Interplanetary Dust Experiment, Tray C09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO201 : Interplanetary Dust Experiment, Tray C09 The flight photograph was taken during the LDEF retrieval and provides an on-orbit view of the C09 integrated tray. When comparing this photograph with the prelaunch photograph, very little difference can be seen. A brown stain is visible around some of the fasteners and on mounting plates. The stain has been attributed to outgassing and contamination from the LDEF and experiment related materials being flown. When compared to the prelaunch photograph, the C09 integrated tray seems to be in excellent condition. The Interplanetary Dust Experiment appears to have a thin brown stain around some of the fasteners and also a small rectangular stain, in the center, along the bottom edge of the detector mounting plate. The IDE seems to be in excellent condition with all hardware intact. The colors seen in the detectors is a reflection of the Orbiter's white cargo bay liner.

  12. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray C09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray C09 The postflight photograph was taken prior to the experiment tray being removed from the LDEF. The tray corner clamp blocks are un-anodized aluminum and that alone accounts for the major difference in color between the corner clamp blocks and the center clamp blocks. The IDE mounting plate and the detector frames and detectors seem to be in excellent condition. Close inspection of the photograph reveals several locations where impacts on detector surfaces are visible. A faint gold or tan stain can be seen around several of the fasteners and in a rectangular configuration, near the center, along the bottom edge of the detector mounting plate. Stains can also be seen near the top right edge of the solar sensor, on the mounting plate, and around the extreme edges of the solar sensor baseplate. The colors and designs seen on the detectors are reflections of the surrounding area.

  13. NFIRAOS: first facility AO system for the Thirty Meter Telescope

    NASA Astrophysics Data System (ADS)

    Herriot, Glen; Andersen, David; Atwood, Jenny; Boyer, Corinne; Byrnes, Peter; Caputa, Kris; Ellerbroek, Brent; Gilles, Luc; Hill, Alexis; Ljusic, Zoran; Pazder, John; Rosensteiner, Matthias; Smith, Malcolm; Spano, Paolo; Szeto, Kei; Véran, Jean-Pierre; Wevers, Ivan; Wang, Lianqi; Wooff, Robert

    2014-07-01

    NFIRAOS, the Thirty Meter Telescope's first adaptive optics system is an order 60x60 Multi-Conjugate AO system with two deformable mirrors. Although most observing will use 6 laser guide stars, it also has an NGS-only mode. Uniquely, NFIRAOS is cooled to -30 °C to reduce thermal background. NFIRAOS delivers a 2-arcminute beam to three client instruments, and relies on up to three IR WFSs in each instrument. We present recent work including: robust automated acquisition on these IR WFSs; trade-off studies for a common-size of deformable mirror; real-time computing architectures; simplified designs for high-order NGS-mode wavefront sensing; modest upgrade concepts for high-contrast imaging.

  14. The 1987 outburst of the BL Lacertid AO 0235 + 164

    NASA Astrophysics Data System (ADS)

    Webb, J. R.; Smith, A. G.

    1989-08-01

    The violently variable BL Lacertid AO 0235 + 164 displayed a 3.24 magnitude outburst in early 1987. This outburst was observed intensively from Rosemary Hill Observatory in three colors. Long term monitoring observations made at Rosemary Hill are examined in an effort to find any recurring timescales associated with this outburst and previous large amplitude outbursts. The energetics of the 1987 outburst are analyzed in terms of the Shields and Wheeler model of a magnetized accretion disk. The timescales identified in the power spectrum (2.8 and 1.6 yr) are input into the model as the storage timescales. Since the emitted energy calculated from the optical burst cannot be stored in a magnetized disk at an allowable radius, it is concluded that either the storage timescales are longer than those identified in the power spectrum, or relativistic beaming effects must be considered, with a Doppler factor of 1.3 to 1.6.

  15. Robo-AO KP: A new era in robotic adaptive optics

    NASA Astrophysics Data System (ADS)

    Riddle, Reed L.; Baranec, Christoph; Law, Nicholas M.; Kulkarni, Shrinivas R.; Duev, Dmitry; Ziegler, Carl; Jensen-Clem, Rebecca M.; Atkinson, Dani Eleanor; Tanner, Angelle M.; Zhang, Celia; Ray, Amy

    2016-01-01

    Robo-AO is the first and only fully automated adaptive optics laser guide star AO instrument. It was developed as an instrument for 1-3m robotic telescopes, in order to take advantage of their availability to pursue large survey programs and target of opportunity observations that aren't possible with other AO systems. Robo-AO is currently the most efficient AO system in existence, and it can achieve an observation rate of 20+ science targets per hour. In more than three years of operations at Palomar Observatory, it has been quite successful, producing technology that is being adapted by other AO systems and robotic telescope projects, as well as several high impact scientific publications. Now, Robo-AO has been selected to take over operation of the Kitt Peak National Observatory 2.1m telescope. This will give Robo-AO KP the opportunity to pursue multiple science programs consisting of several thousand targets each during the three years it will be on the telescope. One-sixth of the observing time will be allocated to the US community through the NOAO TAC process. This presentation will discuss the process adapting Robo-AO to the KPNO 2.1m telescope, the plans for integration and initial operations, and the science operations and programs to be pursued.

  16. Enhancement of archaeological heritage. El Risco de las Cuevas at Perales de Tajuña, Madrid (Spain)

    NASA Astrophysics Data System (ADS)

    Freire-Lista, David Martin; Alvarez de Buergo, Mónica; Fort, Rafael

    2016-04-01

    Heritage conservation has a great impact on the economy of a country. The enhancement of archaeological sites is an investment that promotes tourism and culture. The interdisciplinary knowledge of heritage should be the basis of its management. Preventive actions, non-destructive analytical techniques and monitoring for the conservation of these assets should be promoted. "El Risco de las Cuevas" is a highly decayed and nearly vertical gypsum escarpment which contains a series of dwellings excavated during the Chalcolithic and much more recent times. It is located at Perales de Tajuña, 40 km southeast of Madrid, Spain. This monument is approximately 70 metres high and 500 metres wide. It was listed as a cultural and monumental heritage site by the regional government of Madrid in 1998. The gypsum escarpment housing the dwellings forms part of a lower Miocene unit (Madrid Basin). Debris cones with a mixture of debris from the lower, medium and upper units are found at the bottom of the rockwall. The vulnerability of this monument to atmospheric agents has been studied using "in situ" monitoring techniques of humidity, temperature and rate of rockfalls. Drones have been used for aerial photography in the highest areas of the escarpment and have provided an information network of fractures likely to cause rockfall. Gypsum artificial accelerated ageing has been carried out in the laboratory, including freeze/thaw, wet/dry, thermal shock and dissolution tests. To determine the response of these accelerated ageing processes, density, micro-roughness, ultrasound velocities (Vp and Vs), air permeability and microscopy measurements were made before, during and after ageing tests. Geomorphological studies, rates of decay, material characteristics and durability tests indicate that the decay is controlled by the mineralogy, clay content and porosity of the gypsum rock, as well as microclimate, temperature changes and rock fractures. Rockfalls are particularly relevant in the

  17. Atomic oxygen effects on LDEF experiment AO171

    NASA Technical Reports Server (NTRS)

    Whitaker, Ann F.; Kamenetzky, Rachel R.; Finckenor, Miria M.; Norwood, Joseph K.

    1993-01-01

    The Solar Array Materials Passive Long Duration Exposure Facility (LDEF) Experiment (SAMPLE), AO171, contained in total approximately 100 materials and materials processes with a 300 specimen complement. With the exception of experiment solar cell and solar cell modules, all test specimens were weighed before flight, thus allowing an accurate determination of mass loss as a result of space exposure. Since almost all of the test specimens were thermal vacuum baked before flight, the mass loss sustained can be attributed principally to atomic oxygen attack. The atomic oxygen effects observed and measured in five classes of materials is documented. The atomic oxygen reactivity values generated for these materials are compared to those values derived for the same materials from exposures on short term shuttle flights. An assessment of the utility of predicting long term atomic oxygen effects from short term exposures is given. This experiment was located on Row 8 position A which allowed all experiment materials to be exposed to an atomic oxygen fluence of 6.93 x 10(exp 21) atoms/cm(sup 2) as a result of being positioned 38 degrees off the RAM direction.

  18. LDEF (Flight), AO201 : Interplanetary Dust Experiment, Tray G10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO201 : Interplanetary Dust Experiment, Tray G10 The flight/on-orbit photograph of the G10 experi ment tray was taken from the Orbiter aft flight deck during the LDEF retrieval. A light brown stain can be seen on the experiment tray flanges and to a lesser degree on the IDE Chemglaze Z tained their integrity. A light tan stain on the solar sensor base plate, located in the center of the tray, is more easily seen than that on the IDE mounting plate. Surface defects are highly visible due to the lighting conditions existing at the time the photograph was taken. The lighting angle is such that many impact craters can be seen. Two (2) detectors, located in the twenty (20) detector layout in the lower left corner of the tray, seem to have defects. A triangular shaped discoloration appears on the second detector from the left and in the second row from the bottom. Another irregular shaped discoloration can be seen on the fourth detector from the left and in the third row from the bottom. These discolorations appear to be due to material and/or fabrication defects and not reflected light. The blue colors on the detector's mirror like surface are caused by reflections of the LDEF surroundings.

  19. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray G10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray G10 The IDE experiment appears to be in excellent condition in the postflight photograph. All bond joints seem to have survived the space environment and the experiment hardware seems to be intact. The direction and intensity of the artificial light source has caused hot spots and reflections that tend to wash out the brown stain on the exposed surfaces. A close inspection of individual detectors reveal locations where impacts have occurred and damage is present. In the detector layout in the lower left corner of the tray, two detectors continue to show the discolorations observed in the flight photograph. A triangular shape can be seen in the detector located in the second horizontal row from the bottom and the second vertical row from the left. The other detector, located in the third horizontal row from the bottom and the fourth vertical row from the left has an irregular shaped, very faint, discolora tion. The blue color in the detectors metallic surface is caused by reflections of the surrounding area.

  20. LDEF: Dosimetric measurement results (AO 138-7 experiment)

    NASA Technical Reports Server (NTRS)

    Bourrieau, J.

    1992-01-01

    One of the objectives of the AO 138-7 experiment on board the LDEF was a total dose measurement with Thermo Luminescent Detectors (TLD 100). Two identical cases, both including 5 TLDs inside various aluminum shields, are exposed to the space environment in order to obtain the absorbed dose profile induced. Radiation fluence received during the total mission length was computed, taking into account the trapped particles (solar maximum and solar minimum periods) and the cosmic rays; due to the magnetospheric shielding, the solar proton fluences are negligible on the LDEF orbit. The total dose induced by these radiations inside a semi-infinite plane shield of Al are computed with radiation transport codes. TLD reading are performed after flight; due to the mission duration increase, a post-flight calibration was necessary in order to cover the range of the flight induced dose. The results obtained, similar (+ or - 30 pct.) in both cases, are compared with the dose profile computation. In practice, these LDEF results, with less than a factor 1.4 between measurements and forecasts, reinforce the validity of the computation methods and models used for the long term evaluation of space radiation intensity on low inclination Earth orbits.

  1. Ruled and holographic experiment (AO 138-5)

    NASA Astrophysics Data System (ADS)

    Bonnemason, Francis

    1993-04-01

    The AO 138-5 experiment was designed, via the FRECOPA (FRench COoperative PAyload) experiment with the aim to study the optical behavior of different diffraction gratings submitted to space vacuum long exposure and solar irradiation. Samples were ruled and holographic gratings, masters or replica, and some additional control mirrors with various coatings. The experiment was located on the B3, trailing edge of the LDEF and was protected against Atomic Oxygen flux. The experienced thermal cycling was evaluated from -23 C to 66 C during the flight, 34,000 orbits. The samples (two batches of four pieces) were located on a dedicated plate, by a pair of equivalent gratings or mirrors; optical faces were located on the external side. The plate was inside a canister, which had been opened in space for ten months. When the satellite returned to Kennedy Space Center, the remaining vacuum in the canister was still correct. The analysis focused on the triple point characterization including light efficiency, wavefront flatness quality and stray light level. Tests were conducted on control mirrors and gratings (rules and holographic master or replica) loaded but not exposed to cosmic dust or direct solar irradiations. They did not show any significant variations. Solar exposure had damaged the coating (aluminum and platinum) reflectivity in the Ultra-Violet region; the degradation is higher with the gratings, in terms of efficiency. However, wavefront flatness quality and stray light level tests revealed no additional changes.

  2. Ruled and holographic experiment (AO 138-5)

    NASA Technical Reports Server (NTRS)

    Bonnemason, Francis

    1993-01-01

    The AO 138-5 experiment was designed, via the FRECOPA (FRench COoperative PAyload) experiment with the aim to study the optical behavior of different diffraction gratings submitted to space vacuum long exposure and solar irradiation. Samples were ruled and holographic gratings, masters or replica, and some additional control mirrors with various coatings. The experiment was located on the B3, trailing edge of the LDEF and was protected against Atomic Oxygen flux. The experienced thermal cycling was evaluated from -23 C to 66 C during the flight, 34,000 orbits. The samples (two batches of four pieces) were located on a dedicated plate, by a pair of equivalent gratings or mirrors; optical faces were located on the external side. The plate was inside a canister, which had been opened in space for ten months. When the satellite returned to Kennedy Space Center, the remaining vacuum in the canister was still correct. The analysis focused on the triple point characterization including light efficiency, wavefront flatness quality and stray light level. Tests were conducted on control mirrors and gratings (rules and holographic master or replica) loaded but not exposed to cosmic dust or direct solar irradiations. They did not show any significant variations. Solar exposure had damaged the coating (aluminum and platinum) reflectivity in the Ultra-Violet region; the degradation is higher with the gratings, in terms of efficiency. However, wavefront flatness quality and stray light level tests revealed no additional changes.

  3. Four year experience with the AO Anterior Thoracolumbar Locking Plate.

    PubMed

    Thalgott, J S; Kabins, M B; Timlin, M; Fritts, K; Giuffre, J M

    1997-05-01

    For decades spinal surgeons have attempted to design simple, single stage anterior internal fixation systems for the thoracic and lumbar spine. Early devices presented both biomechanical and technical problems. The AO Anterior Thoracolumbar Locking Plate (ATLP) was designed to solve some of the problems encountered with early anterior instrumentation. The ATLP system is constructed in Commercially Pure titanium. It is a low profile device indicated for use for unstable burst fractures in the anterior column; metastatic tumor management; and degenerative diseases of the thoracolumbar spine between levels T10 and L5. Implantation of the device involves direct anterior decompression with sagittal reduction and corpectomy. This is followed by grafting reconstruction, and plate fixation. This device has been implanted in 25 patients with an average follow-up of 38 months. There were five (5) broken screws in three (3) patients, and no broken plates. Implant related postoperative complications included two misplaced screws. Preliminary results indicate that the ATLP system seems to be a safe, low profile, MRI/CT compatible device that provides definitive single stage fixation of the anterior spinal column. PMID:9160452

  4. Patterns of Impairments in AOS and Mechanisms of Interaction between Phonological and Phonetic Encoding

    ERIC Educational Resources Information Center

    Laganaro, Marina

    2012-01-01

    Purpose: One reason why the diagnosis of apraxia of speech (AOS) and its underlying impairment are often debated may lie in the fact that most patients do not display pure patterns of AOS. Mixed patterns are clearly acknowledged at other levels of impairment (e.g., lexical-semantic and lexical-phonological), and they have contributed to debate…

  5. MagAO: Status and on-sky performance of the Magellan adaptive optics system

    NASA Astrophysics Data System (ADS)

    Morzinski, Katie M.; Close, Laird M.; Males, Jared R.; Kopon, Derek; Hinz, Phil M.; Esposito, Simone; Riccardi, Armando; Puglisi, Alfio; Pinna, Enrico; Briguglio, Runa; Xompero, Marco; Quirós-Pacheco, Fernando; Bailey, Vanessa; Follette, Katherine B.; Rodigas, T. J.; Wu, Ya-Lin; Arcidiacono, Carmelo; Argomedo, Javier; Busoni, Lorenzo; Hare, Tyson; Uomoto, Alan; Weinberger, Alycia

    2014-07-01

    MagAO is the new adaptive optics system with visible-light and infrared science cameras, located on the 6.5-m Magellan "Clay" telescope at Las Campanas Observatory, Chile. The instrument locks on natural guide stars (NGS) from 0th to 16th R-band magnitude, measures turbulence with a modulating pyramid wavefront sensor binnable from 28×28 to 7×7 subapertures, and uses a 585-actuator adaptive secondary mirror (ASM) to provide at wavefronts to the two science cameras. MagAO is a mutated clone of the similar AO systems at the Large Binocular Telescope (LBT) at Mt. Graham, Arizona. The high-level AO loop controls up to 378 modes and operates at frame rates up to 1000 Hz. The instrument has two science cameras: VisAO operating from 0.5-1μm and Clio2 operating from 1-5 μm. MagAO was installed in 2012 and successfully completed two commissioning runs in 2012-2013. In April 2014 we had our first science run that was open to the general Magellan community. Observers from Arizona, Carnegie, Australia, Harvard, MIT, Michigan, and Chile took observations in collaboration with the MagAO instrument team. Here we describe the MagAO instrument, describe our on-sky performance, and report our status as of summer 2014.

  6. SCExAO as a precursor to an ELT exoplanet direct imaging instrument

    NASA Astrophysics Data System (ADS)

    Jovanovic, Nemanja; Guyon, Olivier; Martinache, Frantz; Clergeon, Christophe; Singh, Garima; Vievard, Sebastien; Kudo, Tomoyuki; Garrel, Vincent; Norris, Barnaby; Tuthill, Peter; Stewart, Paul; Huby, Elsa; Perrin, Guy; Lacour, Sylvestre

    2013-12-01

    The Subaru Coronagraphic Extreme AO (SCExAO) instrument consists of a high performance Phase Induced Amplitude Apodisation (PIAA) coronagraph combined with an extreme Adaptive Optics (AO) system operating in the near-infrared (H band). The extreme AO system driven by the 2000 element deformable mirror will allow for Strehl ratios>90% to be achieved in the H-band when it goes closed loop. This makes the SCExAO instrument a powerful platform for high contrast imaging down to angular separations of the order of 1 lambda/D and an ideal testbed for exploring coronagraphic techniques for ELTs. In this paper we report on the recent progress in regards to the development of the instrument, which includes the addition of a visible bench that makes use of the light at shorter wavelengths not currently utilized by SCExAO and closing the loop on the tip/tilt wavefront sensor. We will also discuss several exciting guest instruments which will expand the capabilities of SCExAO over the next few years; namely CHARIS which is a integral field spectrograph as well as VAMPIRES, a visible aperture masking experiment based on polarimetric analysis of circumstellar disks. In addition we will elucidate the unique role extreme AO systems will play in enabling high precision radial velocity spectroscopy for the detection of small companions.

  7. AO-308: the high-order adaptive optics system at Big Bear Solar Observatory

    NASA Astrophysics Data System (ADS)

    Shumko, Sergey; Gorceix, Nicolas; Choi, Seonghwan; Kellerer, Aglaé; Cao, Wenda; Goode, Philip R.; Abramenko, Volodymyr; Richards, Kit; Rimmele, Thomas R.; Marino, Jose

    2014-08-01

    In this paper we present Big Bear Solar Observatory's (BBSO) newest adaptive optics system - AO-308. AO-308 is a result of collaboration between BBSO and National Solar Observatory (NSO). AO-308 uses a 357 actuators deformable mirror (DM) from Xinetics and its wave front sensor (WFS) has 308 sub-apertures. The WFS uses a Phantom V7.3 camera which runs at 2000 Hz with the region of interest of 416×400 pixels. AO-308 utilizes digital signal processors (DSPs) for image processing. AO-308 has been successfully used during the 2013 observing season. The system can correct up to 310 modes providing diffraction limited images at all wavelengths of interest.

  8. Robo-AO: Initial results from the first autonomous laser guide star adaptive optics instrument

    NASA Astrophysics Data System (ADS)

    Riddle, R. L.; Baranec, C.; Law, N. M.; Ramaprakash, A. N.; Tendulkar, S.; Hogstrom, K.; Bui, K.; Burse, M.; Chordia, P.; Das, H.; Dekany, R.; Kulkarni, S.; Punnadi, S.; Smith, R.

    2014-12-01

    Large surveys are discovering thousands of objects which require further characterization at high angular resolution. The demands on space-based observatories and large telescopes with AO systems leave them generally unavailable for large high angular resolution surveys. To address this gap, we have developed Robo-AO, the first robotic laser AO system, as an economical and efficient imaging instrument for 1-3 m class telescopes. Observations of over 200 stellar objects per night have routinely been performed, with target-to-target observation overheads of less than 1.5 minutes. Scientific programs of several thousands of targets can be executed in mere weeks, and Robo-AO has already completed the three largest AO surveys to date.

  9. A reflective Gaussian coronagraph for ExAO: laboratory performance

    NASA Astrophysics Data System (ADS)

    Park, Ryeojin; Close, Laird M.; Siegler, Nick; Nielsen, Eric L.; Stalcup, Thomas

    2006-06-01

    We report laboratory results of a coronagraphic testbed to assess the intensity reduction differences between a "Gaussian" tapered focal plane coronagraphic mask and a classical hard-edged "Top Hat" function mask at Extreme Adaptive Optics (ExAO) Strehl ratios of ~94%. However, unlike a traditional coronagraph design, we insert a reflective focal plane mask at 45 ° to the optical axis and used a "spot of Arago blocker" (axicon stop) before a final image in order to block additional mask edge-diffracted light. The testbed simulates the optical train of ground-based telescopes (in particular the 8.1m Gemini North telescope) and includes one spider vane and different mask radii (r= 1.9λ/D, 3.7λ/D, 7.4λ/D) and two types of reflective focal plane masks (hard-edged "Top Hat" and "Gaussian" tapered profiles). In order to investigate the performance of these competing coronagraphic designs with regard to extra-solar planet detection sensitivity, we utilize the simulation of realistic extra-solar planet populations (Nielsen et al. 2006). With an appropriate translation of our laboratory results to expected telescope performance, a "Gaussian" tapered mask radius of 3.7λ/D with an axicon stop performs best (highest planet detection sensitivity). For a full survey with this optimal design, the simulation predicts ~30% more planets detected compared to a similar sized "Top Hat" function mask with an axicon stop. Using the best design, the "point contrast ratio" between the stellar PSF peak and the coronagraphic PSF at 10λ/D (0.4" in H band if D = 8.1m) is 1.4 x 10 6. This is ~10 times higher than a classical Lyot "Top Hat" coronagraph.

  10. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray B12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray B12 The postflight photograph shows little change of the exposed surfaces when compared with the prelaunch photograph. Although not noticable in the photograph, a light coating of contamination was seen on all experiment surfaces in this location. The difference in colors of the IDE detectors, located on the right hand mounting plate, is a result of the reflected surroundings and not related to space exposure. A close observation of the detector surfaces reveal that some damage has occured from meteroid and/or debris impacts. One impact crater can be seen, upper right quadrant, on the detector located in the sixth (6th) row down from the top and the fifth (5th) row from the right. Other impacts, smaller in size, show as small white dots on the detector surface. The solar sensor seems to have changed little, if any. However, the color of the solar array baseplate, showing indications of contamination, appears to be darker than the detector mounting plate. The center section cover plate shows little change when compared with the pre-launch photograph. However, during inspection, a light coat of the brown contamination has been observed on all surfaces. The color of the bonding material (RTV) used to secure several thin specimen, sapphire, to individual mounting plates has changed from pink to gold. At one location, that of a single specimen, the bonding material is more gray than gold in color. This has been attributed to the specimen being considerably thicker. The EPDS thermal cover in the right hand side of the tray shows a light coating of brown contamination on the Chemglaze II A-276 white paint.

  11. Multi-conjugate AO for the European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Montilla, I.; Béchet, C.; Le Louarn, M.; Tallon, M.; Sánchez-Capuchino, J.; Collados Vera, M.

    2012-07-01

    The European Solar Telescope (EST) will be a 4-meter diameter world-class facility, optimized for studies of the magnetic coupling between the deep photosphere and upper chromosphere. It will specialize in high spatial resolution observations and therefore it has been designed to incorporate an innovative built-in Multi-Conjugate Adaptive Optics system (MCAO). It combines a narrow field high order sensor that will provide the information to correct the ground layer and a wide field low order sensor for the high altitude mirrors used in the MCAO mode. One of the challenging particularities of solar AO is that it has to be able to correct the turbulence for a wide range of observing elevations, from zenith to almost horizon. Also, seeing is usually worse at day-time, and most science is done at visible wavelengths. Therefore, the system has to include a large number of high altitude deformable mirrors. In the case of the EST, an arrangement of 4 high altitude DMs is used. Controlling such a number of mirrors makes it necessary to use fast reconstruction algorithms to deal with such large amount of degrees of freedom. For this reason, we have studied the performance of the Fractal Iterative Method (FriM) and the Fourier Transform Reconstructor (FTR), to the EST MCAO case. Using OCTOPUS, the end-to-end simulator of the European Southern Observatory, we have performed several simulations with both algorithms, being able to reach the science requirement of a homogeneous Strehl higher that 50% all over the 1 arcmin field of view.

  12. AO Capabilities at the MMT for the User

    NASA Astrophysics Data System (ADS)

    Lloyd-Hart, Michael M.

    2009-05-01

    The MMT operates a facility natural guide star (NGS) AO system. Diffraction limited imaging and medium and high resolution spectroscopy in the near IR are offered over the full isoplanatic field with the ARIES instrument.The system also offers imaging with unique sensitivity in the thermal IR from 3 to 10 microns thanks to its use of an adaptive secondary mirror. L and M band imaging is offered with Clio which has a 12x15 arcsec field of view with Nyquist sampling if the diffraction limt. Recent M band images from Clio show the planetary system around HR8799. In addition, 10 - 25 micron imaging is offered with the MIRAC camera, which may also be operated as a Bracewell nulling interferometer. In this mode, two large subapertures are defined within the pupil. Light from the two is combined so as to cancel the light from an unresolved star through destructive interference, while the environs are imaged in constructive interference. In this way, dust disks and planetary systems may be imaged with greatly improved contrast. The MMT also operates the first astronomical adaptive optics system to employ multiple laser guide stars (LGS). Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wavefront correction within the 2 arcmin diameter laser beacon constellation, routinely reducing the stellar image widths to < 0.3 arcsec in the J - K bands. An imaging camera,PISCES, is available for these bands with 2 arcmin field of view sampled at 0.1 arcsec/pixel. In addition, L and M band imaging will be available with Clio in the fall of 2009, opening up near all-sky coverage with near-diffraction limited image quality and emissivity of just 7%.

  13. Bringing the Visible Universe into Focus with Robo-AO

    PubMed Central

    Baranec, Christoph; Riddle, Reed; Law, Nicholas M.; Ramaprakash, A.N.; Tendulkar, Shriharsh P.; Bui, Khanh; Burse, Mahesh P.; Chordia, Pravin; Das, Hillol K.; Davis, Jack T.C.; Dekany, Richard G.; Kasliwal, Mansi M.; Kulkarni, Shrinivas R.; Morton, Timothy D.; Ofek, Eran O.; Punnadi, Sujit

    2013-01-01

    focus a high-power laser beam in the direction of the astronomical target to create an artificial reference of known shape, also known as a 'laser guide star'. The Robo-AO laser adaptive optics system2,3 employs a 10-W ultraviolet laser focused at a distance of 10 km to generate a laser guide star. Wavefront sensor measurements of the laser guide star drive the adaptive optics correction resulting in diffraction-limited images that have an angular resolution of ~0.1 arc seconds on a 1.5-m telescope. PMID:23426078

  14. LDEF: Dosimetric measurement results (AO 138-7 experiment)

    NASA Technical Reports Server (NTRS)

    Bourrieau, J.

    1993-01-01

    One of the objectives of the AO 138-7 experiment on board the Long Duration Exposure Facility (LDEF) was a total dose measurement with Thermo Luminescent Detectors (TLD 100). Two identical packages, both of them including five TLD's inside various aluminum shields, are exposed to the space environment in order to obtain the absorbed dose profile. Radiation fluence received during the total mission length was computed, taking into account the trapped particles (AE8 and AP8 models during solar maximum and minimum periods) and the cosmic rays; due to the magnetospheric shielding the solar proton fluences are negligible on the LDEF orbit. The total dose induced by these radiations inside a semi infinite plane shield of aluminum are computed with the radiation transport codes available at DERTS. The dose profile obtained is in good agreement with the evaluation by E.V. Benton. TLD readings are performed after flight; due to the mission duration increase a post flight calibration was necessary in order to cover the range of the in flight induced dose. The results obtained, similar (plus or minus 30 percent) for both packages, are compared with the dose profile computation. For thick shields it seems that the measurements exceed the forecast (about 40 percent). That can be due to a cosmic ray and trapped proton contributions coming from the backside (assumed as perfectly shielded by the LDEF structure in the computation), or to an underestimate of the proton or cosmic ray fluences. A fine structural shielding analysis should be necessary in order to determine the origin of this slight discrepancy between forecast and in flight measurements. For the less shielded dosimeters, mainly exposed to the trapped electron flux, a slight overestimation of the dose (less than 40 percent) appears. Due to the dispersion of the TLD's response, this cannot be confirmed. In practice these results obtained on board LDEF, with less than a factor 1.4 between measurements and forecast

  15. Bringing the visible universe into focus with Robo-AO.

    PubMed

    Baranec, Christoph; Riddle, Reed; Law, Nicholas M; Ramaprakash, A N; Tendulkar, Shriharsh P; Bui, Khanh; Burse, Mahesh P; Chordia, Pravin; Das, Hillol K; Davis, Jack T C; Dekany, Richard G; Kasliwal, Mansi M; Kulkarni, Shrinivas R; Morton, Timothy D; Ofek, Eran O; Punnadi, Sujit

    2013-01-01

    a high-power laser beam in the direction of the astronomical target to create an artificial reference of known shape, also known as a 'laser guide star'. The Robo-AO laser adaptive optics system, employs a 10-W ultraviolet laser focused at a distance of 10 km to generate a laser guide star. Wavefront sensor measurements of the laser guide star drive the adaptive optics correction resulting in diffraction-limited images that have an angular resolution of ~0.1 arc seconds on a 1.5-m telescope. PMID:23426078

  16. Isolation and characterization of a novel bacterium, Sphingomonas bisphenolicum strain AO1, that degrades bisphenol A.

    PubMed

    Oshiman, Ko-ichi; Tsutsumi, Yuji; Nishida, Tomoaki; Matsumura, Yoshinobu

    2007-04-01

    Bisphenol A (2,2-bis(4-hydroxyphenyl) propane, BPA), which is used as a synthetic resin material or a plasticizer, is a pollutant that possesses endocrine-disrupting activity. Bioremediation of BPA is used to decrease its polluting effects, and here we report a novel bacterial strain AO1, which is able to degrade BPA. This strain was isolated using enrichment cultivation from a soil sample from a vegetable-growing field; the sample was one of 500 soil samples collected across Japan. Strain AO1 degraded 100 mg/l BPA to an undetectable level within 6 h in MYPG medium (containing malt extract, yeast extract, peptone, and glucose) and within 48 h in minimum medium containing 1% glucose at 30 degrees C. Strain AO1 can utilize BPA as a sole source of carbon and as an energy source under aerobic conditions. The estrogenic activity of BPA in MYPG medium was ultimately reduced by strain AO1, although the activity initially increased. Taxonomical analysis showed that strain AO1 is closely related to Sphingomonas chlorophenolicum and S. herbicidovorans, neither of which have a capacity for BPA degradation. DNA-DNA hybridization showed that strain AO1 is a novel species of the Sphingomonas genus, and we designated AO1 as S. bisphenolicum. PMID:16821103

  17. Calibration of a curvature sensor/bimorph mirror AO system: interaction matrix measurement on MACAO systems

    NASA Astrophysics Data System (ADS)

    Oberti, Sylvain; Bonnet, Henri; Fedrigo, Enrico; Ivanescu, Liviu; Kasper, Markus E.; Paufique, Jerome

    2004-10-01

    The accurate calibration of an AO system is fundamental in order to reach the top performance expected from design. To improve this aspect, we propose procedures for calibrating a curvature AO system in view of optimizing performances and robustness, based on the experience accumulated by the ESO AO team through the development of MACAO systems for VLTI and SINFONI. The approach maximizes the quality of the Interaction Matrix (IM) while maintaining the system in its linear regime and minimizing noise and bias on the measurement.

  18. LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12 The prelaunch photograph shows the six (6) inch deep Interplanetary Dust Experiment (IDE) master control tray. The tray has three (3) mounting/cover plates elevated on fiberglass stand-offs to provide clearance and protection for hardware and electronics located underneath. The stand-offs also raise the plates to a level that minimizes shading of detectors by the tray sidewalls. The mounting plate located at the left hand end of the tray is populated with eighty (80) metaloxide-silicon (MOS) capacitor-type impact sensors and one (1) solar sensor that is located approximately in the center of the mounting plate. The IDE sensors are two (2) inch diameter MOS capacitor structures approximately 250 um thick. The detectors are formed by growing either 0.4um or 1.0um thick silicon oxide, SiO2, layer on the 250um thick, B-doped polished silicon wafer. The top metal contact, the visible surface, was formed by vapor deposition of 1000A of aluminum on the SiO2 surface. Aluminum was also vapor deposited on the backside to form the contact with the silicon substrate. Gold wires are bonded to the front and back aluminum layers for use in connecting the detectors to the circuits. The complete wafers, IDE detectors, are mounted on chromic anodized aluminum frames by bonding the detector backside to the aluminum frame with a space qualified RTV silicon adhesive, de-volatized RTV-511. The difference in colors of the detectors is caused by reflections in the metallized surfaces. A reflection of one of the technicians is visible in the three (3) rows of detector on the left hand side of the mounting plate. The solar sensor, located at the mounting plate center, consist of four (4) silicon solar cells connected in series and associated circuity bonded to an aluminum baseplate. The solar sensor registered each orbital sunrise independant of LDEF orientation at the time of sunrise. When IDE solar sensor data from the six

  19. The RISCO RapidIce Viewer: An application for monitoring the polar ice sheets with multi-resolution, multi-temporal, multi-sensor satellite imagery

    NASA Astrophysics Data System (ADS)

    Herried, B.; Porter, C. C.; Morin, P. J.; Howat, I. M.

    2013-12-01

    The Rapid Ice Sheet Change Observatory (RISCO) is a NASA-funded, inter-organizational collaboration created to provide a systematic framework for gathering, processing, analyzing, and distributing consistent satellite imagery of polar ice sheet change for Antarctica and Greenland. RISCO gathers observations over areas of rapid change and makes them easily accessible to investigators, media, and the general public. As opposed to existing data centers, which are structured to archive and distribute diverse types of raw data to end users with the specialized software and skills to analyze them, RISCO distributes processed georeferenced raster image data products in JPEG and GeoTIFF formats, making them immediately viewable in a browser-based application. Currently, the archive includes 16 sensors including: MODIS Terra, MODIS Aqua, MODIS Terra Bands 3-6-7, Landsat MSS, Landsat TM, Landsat ETM+, Landsat 8 OLI, EO-1, SPOT, ASTER VNIR, Operation IceBridge ATM and LVIS, and commercial satellites such as WorldView-1, WorldView-2, QuickBird-2, GeoEye-1 and IKONOS. The RISCO RapidIce Viewer is a lightweight JavaScript application that provides an interface to viewing and downloading the satellite imagery from predefined areas-of-interest (or 'subsets'), which are normally between 10,000 and 20,000 sq km. Users select a subset (from a map or drop-down) and the archive of individual granules is loaded in a thumbnail grid, sorted chronologically (newest first). For each thumbnail, users can choose to view a larger preview JPG, download a GeoTIFF, or be redirected back to the original data center to see the original imagery or view metadata. There are several options for filtering displayed including by sensor, by date range, by month, or by cloud cover. Last, users can select multiple images to play back as an animation. The RapidIce Viewer is an easy-to-use, software independent application for researchers to quickly monitor daily changes in ice sheets or download historical

  20. East Asian winter temperature variation associated with the combined effects of AO and WP pattern

    NASA Astrophysics Data System (ADS)

    Park, Hye-Jin; Ahn, Joong-Bae

    2016-04-01

    The combined effects of the Arctic Oscillation (AO) and Western Pacific (WP) teleconnection pattern on the East Asian winter monsoon (EAWM) over the last 56 years (1958/59-2013/2014) were investigated using NCEP/NCAR reanalysis data (Park and Ahn, 2015). The study results revealed that the effect of the AO on winter temperature in East Asia could be changed depending on the phases of the WP pattern in the North Pacific. The negative relationship between the EAWM and the AO increased when the AO and WP were in-phase with each other. Hence, when winter negative (positive) AO was accompanied by negative (positive) WP, negative (positive) temperature anomalies were dominant across the entire East Asia region. Conversely, when the AO and WP were of-of-phase, the winter temperature anomaly in East Asia did not show distinct changes. Furthermore, from the perspective of stationary planetary waves, the zonal wavenumber-2 patterns of sea level pressure and geopotential height at 500hPa circulation strengthened when the AO and WP were in-phase but were not significant for the out-of-phase condition. It explained the possible mechanism of the combined effects of the AO and WP on the circulation related to EAWM. Reference Park, H.-J., and J.-B. Ahn (2015) Combined effect of the Arctic Oscillation and the Western Pacific pattern on East Asia winter temperature, Clim. Dyn. DOI:10.1007/s00382-015-2763-2. Acknowledgements This work was funded by the Korea Meteorological Administration Research and Development Program under grant KMIPA2015-2081.

  1. Building a reliable, scalable and affordable RTC for AO instruments on ELTs

    NASA Astrophysics Data System (ADS)

    Gratadour, Damien; Sevin, Arnaud; Perret, Denis; Brule, Julien

    2013-12-01

    Addressing the unprecedented amount of computing power needed by the ELTs AO instruments real-time controllers (RTC) is one of the key technological developments required for the design of the next generation AO systems. Throughput oriented architectures such as GPUs, providing orders of magnitude greater computational performance than high-end CPUs, have recently appeared as attractive and economically viable candidates since the fast emergence of devices capable of general purpose computing. However, using for real-time applications a I/0 device which cannot be scheduled nor controlled internally by the operating system but is sent commands through a closed source driver comes with a number of challenges. Building on the experience of almost real-time end-to-end simulations using GPUs, and relying on the development of the COMPASS platform, a unified and optimized framework for AO simulations and real-time control, our team has engaged into the development of a scalable, heterogeneous GPU-based prototype for an AO RTC. In this paper, we review the main challenges arising when utilizing GPUs in real-time systems for AO and rank them in terms of impact significance and available solutions. We present our strategy, to mitigate these issues including the general architecture of our prototype, the real-time core and additional dedicated components for data acquisition and distribution. Finally, we discuss the expected performance in terms of latency and jitter on the basis of realistic benchmarks and focusing on the dimensioning of the MICADO AO module RTC.

  2. Robo-AO: Initial results from the first autonomous laser guide star adaptive optics instrument

    NASA Astrophysics Data System (ADS)

    Riddle, R.; Baranec, C.; Law, N. M.; Ramaprakash, A. N.; Tendulkar, S.; Hogstrom, K.; Bui, K.; Burse, M.; Chordia, P.; Das, H.; Dekany, R.; Kulkarni, S.; Punnadi, S.; Smith, R.

    2014-03-01

    Large surveys, such as the Kepler mission and Palomar Transient Factory, are discovering upwards of thousands of objects which require further characterization at angular resolutions significantly finer than normally allowed by atmospheric seeing. The demands on precious space-based observatories (i.e. Hubble Space Telescope) and large telescopes with adaptive optics (AO) systems (i.e. Keck, VLT, Gemini) leave them generally unavailable for high angular resolution surveys of more than a few hundred targets at a time. To address the gap between scientific objects and available telescopes, we have developed Robo-AO, the first robotic laser AO system, as an economical and efficient imaging instrument for the more readily available 1-3 m class telescopes. The Robo-AO system system demonstrates angular resolutions approaching the visible diffraction limit of the Palomar 60-inch telescope. Observations of over 200 stellar objects per night have routinely been performed, with target-to-target observation overheads of less than 1.5 minutes. Scientific programs requiring high-resolution follow-up characterization of several thousands of targets can thus be executed in mere weeks, and Robo-AO has already completed the three largest AO surveys to date.

  3. Parameterising E-ELT AO PSFs for detailed science simulations for HARMONI

    NASA Astrophysics Data System (ADS)

    Zieleniewski, Simon; Thatte, Niranjan

    2013-12-01

    With the first ELTs around the corner it is becoming ever more important to determine observational strategies and assess the prospective success of observing programs prior to making the observations. To this end, scientific simulations need to become more refined to understand the criteria required for a specific science case. We address the science simulations for HARMONI, an AO assisted first light integral field spectrograph (IFS) for the E-ELT. AO PSFs vary markedly as a function of wavelength and type of AO system used, so there is need to create detailed PSFs across all IFS wavelength channels for accurate simulations. Detailed AO simulations have shown that for LTAO on the E-ELT, Strehl ratios can vary from 0.5E-3 in V-band up to 0.5 in K-band. Using a single PSF for an entire datacube (especially with large instantaneous wavelength coverage) could introduce misleading features into simulated observations using HARMONI. We have developed a method to parameterize detailed PSFs using analytical models, which can then be interpolated as a function of wavelength. This allows us to create accurate, but computationally inexpensive, AO PSF datacubes for HARMONI simulations. This shall be developed to cover LTAO, SCAO and GLAO/no-AO PSFs for a range of observing parameters.

  4. Requirements Modeling with the Aspect-oriented User Requirements Notation (AoURN): A Case Study

    NASA Astrophysics Data System (ADS)

    Mussbacher, Gunter; Amyot, Daniel; Araújo, João; Moreira, Ana

    The User Requirements Notation (URN) is a recent ITU-T standard that supports requirements engineering activities. The Aspect-oriented URN (AoURN) adds aspect-oriented concepts to URN, creating a unified framework that allows for scenario-based, goal-oriented, and aspect-oriented modeling. AoURN is applied to the car crash crisis management system (CCCMS), modeling its functional and non-functional requirements (NFRs). AoURN generally models all use cases, NFRs, and stakeholders as individual concerns and provides general guidelines for concern identification. AoURN handles interactions between concerns, capturing their dependencies and conflicts as well as the resolutions. We present a qualitative comparison of aspect-oriented techniques for scenario-based and goal-oriented requirements engineering. An evaluation carried out based on the metrics adapted from literature and a task-based evaluation suggest that AoURN models are more scalable than URN models and exhibit better modularity, reusability, and maintainability.

  5. [Discussion on academic origin of Ao shi shang han jin jing lu (Ao's Records of golden mirror on cold pathogenic diseases].

    PubMed

    Liang, Rong; Wang, Zhaoping

    2002-07-01

    Ao shi shang han jin jing lu (Ao's Records of Golden Mirror on Cold Pathogenic Diseases) is the extant first work of lingual diagnosis. It is demonstrated that the author of this book is categorized under the school of Liu Wansu based on the location of disease, the nature of disease, therapies and drugs, and pathogenesis in pathological lingual pictures described in this book. The lingual diagnosis was based on Liu Wansu's theory of fire - heat, and used for diagnosing warm diseases. Intuitionistic vision was used in this book to prove the direct relation between red tongue and heat syndrome, which was the important joint for the theory of warm diseases to derive from the theory of cold pathogenic diseases. At the same time, the set up of the model of diagnosis and treatment for red tongue - inner heat syndrome, and clearing inner heat is established. PMID:12639446

  6. Optical-X-ray Observations of BL Lacertae Object AO 0235+164

    NASA Astrophysics Data System (ADS)

    Howard, Emily S.; Webb, James R.; Balonek, Thomas J.; McGrath, Elizabeth; Shrader, Chris R.

    1998-11-01

    The BL Lacertea object AO 0235+164 dramatically increased in brightness on October 20, 1997. This outburst was observed with the 1 meter SARA (Southeastern Association for Research in Astronomy) telescope located at Kitt Peak National Observatory (KPNO) located southwest of Tucson, Arizona. As a result of our observations, AO 0235+164 was also observed during the outbust by the Rossi X-ray Timing Experiment (RXTE) and Foggy Bottom Observaotry, Colgate Univserity, New York as a part of a Target of Opportunity (TOO) program. We present here the historical lightcurve of AO 0235+164, Optical observations during the ourtburst from the SARA and Foggy Bottom Observatories and X-ray observations from RXTE. Also, we present multifrequency data during this period and compare the variability of the Optical and X-ray bands.

  7. Deep-water sponges (Porifera) from Bonaire and Klein Curaçao, Southern Caribbean.

    PubMed

    Van Soest, Rob W M; Meesters, Erik H W G; Becking, Leontine E

    2014-01-01

    Four submersible dives off the coast of Bonaire (Caribbean Netherlands) and Klein Curaçao (Curaçao) to depths of 99.5-242 m, covering lower mesophotic and upper dysphotic zones, yielded 52 sponge specimens belonging to 31 species. Among these we identified 13 species as new to science. These are Plakinastrella stinapa n. sp., Pachastrella pacoi n. sp., Characella pachastrelloides n. sp., Geodia curacaoensis n. sp., Caminus carmabi n. sp., Discodermia adhaerens n. sp., Clathria (Microciona) acarnoides n. sp., Antho (Acarnia) pellita n. sp., Parahigginsia strongylifera n. sp., Calyx magnoculata n. sp., Neopetrosia dutchi n. sp., Neopetrosia ovata n. sp. and Neopetrosia eurystomata n. sp. We also report an euretid hexactinellid, which belongs to the rare genus Verrucocoeloidea, recently described (2014) as V. liberatorii Reiswig & Dohrmann. The remaining 18 already known species are all illustrated by photos of the habit, either in situ or 'on deck', but only briefly characterized in an annotated table to confirm their occurrence in the Southern Caribbean. The habitat investigated-steep limestone rocks, likely representing Pleistocene fossil reefs--is similar to deep-water fossil reefs at Barbados of which the sponges were sampled and studied by Van Soest and Stentoft (1988). A comparison is made between the two localities, showing a high degree of similarity in sponge composition: 53% of the present Bonaire-Klein Curaçao species were also retrieved at Barbados. At the level of higher taxa (genera, families) Bonaire-Klein Curaçao shared approximately 80% of its lower mesophotic and upper dysphotic sponge fauna with Barbados, despite a distance between them of 1000 km, indicating high faunal homogeneity. We also preliminarily compared the shallow-water (euphotic) sponge fauna of Curaçao with the combined data available for the Barbados, Bonaire and Klein Curaçao mesophotic and upper dysphotic sponges, which resulted in the conclusion that the two faunas show only

  8. [Study on Provenance of Kraak Porcelains from "Nan'ao I" Shipwreck].

    PubMed

    Du, Jing-nan; Chen, Yue; Li, Nai-sheng; Ming, Chao-fang; Zhu, Jian; Luo, Wu-gan

    2015-06-01

    The "Kraak Porcelain" was a kind of Blue and White Porcelain which exported from China to Europe in Ming and Qing period. The study of Kraak Porcelain is a focus issue in international field of porcelain research. In 2007, the discovery of "Nan'ao I" Shipwreck of Ming Dynasty and the porcelains loaded in it, provided precious materials for the research on Kraak Porcelain. In this paper, we explored the provenance of 10 Kraak Porcelain samples from Nan'ao I, using both traditional visual method and WDXRF. PMID:26601402

  9. Development of vibration source requirements for TMT to ensure AO performance

    NASA Astrophysics Data System (ADS)

    MacMartin, Doug; Thompson, Hugh

    2013-12-01

    In order for TMT to deliver the required adaptive optics (AO) image quality, vibrationsources throughout the observatory need to be understood and their resulting optical response characterized.The sensitivity to vibration has been determined using a finite element model of the telescopestructure and mirror segments coupled to optical models. Frequency dependent models of the AO, activeoptics and mount control systems are included allowing end-to-end assessment of vibration sourceson AO-corrected image quality; future work will improve estimates of the propagation of vibrationsfrom equipment in the summit support building and enclosure to the telescope pier. Modeling separatelypredicts effects on image jitter caused by relative rigid body motion of main optical elements, and thedynamic motion of the 492 individual primary mirror segments. These results have been used to developallocated requirements on source amplitudes at different locations and as a function of frequency, whichwill lead to subsystem design requirements (e.g. for isolation systems at various locations both in thesupport building and enclosure and on the telescope structure). In order to meet an aggressive target forthis contribution to the AO error budget, vibration forces on the telescope itself must be limited to a fewNewtons in the most sensitive frequency range of 5-20Hz; larger forces of order 100N can be toleratedfor equipment mounted off the telescope in the summit facilities building.

  10. Effects of adrenergic agents on the expression of zebrafish (Danio rerio) vitellogenin Ao1

    SciTech Connect

    Yin Naida; Jin Xia; He Jiangyan; Yin Zhan

    2009-07-01

    Teleost vitellogenins (VTGs) are large multidomain apolipoproteins, traditionally considered to be estrogen-responsive precursors of the major egg yolk proteins, expressed and synthesized mainly in hepatic tissue. The inducibility of VTGs has made them one of the most frequently used in vivo and in vitro biomarkers of exposure to estrogen-active substances. A significant level of zebrafish vtgAo1, a major estrogen responsive form, has been unexpectedly found in heart tissue in our present studies. Our studies on zebrafish cardiomyopathy, caused by adrenergic agonist treatment, suggest a similar protective function of the cardiac expressed vtgAo1. We hypothesize that its function is to unload surplus intracellular lipids in cardiomyocytes for 'reverse triglyceride transportation' similar to that found in lipid transport proteins in mammals. Our results also demonstrated that zebrafish vtgAo1 mRNA expression in heart can be suppressed by both {alpha}-adrenergic agonist, phenylephrine (PE) and {beta}-adrenergic agonist, isoproterenol (ISO). Furthermore, the strong stimulation of zebrafish vtgAo1 expression in plasma induced by the {beta}-adrenergic antagonist, MOXIsylyl, was detected by Enzyme-Linked ImmunoSorbent Assay (ELISA). Such stimulation cannot be suppressed by taMOXIfen, an antagonist to estrogen receptors. Thus, our present data indicate that the production of teleost VTG in vivo can be regulated not only by estrogenic agents, but by adrenergic signals as well.

  11. SWAS-AOS: the first acousto-optical spectrometer in space

    NASA Astrophysics Data System (ADS)

    Frerick, Johannes; Klumb, Markus; Schieder, Rudolf; Tolls, Volker; Winnewisser, Gisbert F.

    1999-12-01

    On December 5, 1998, the Submillimeter Wave Astronomy Satellite has been launched with a PEGASUS carrier after more than 3 years delay. SWAS is observing molecular line signals (H2O, 13CO, Cl, O2 and H2 18O) from astronomical sources at frequencies between 487 and 557 GHz. SWAS is the first sub-millimeter heterodyne space mission, and, for the spectral analysis of the received signals, it carries the first acousto-optical spectrometer (AOS) in space. The AOS has been built at University of Cologne, and it covers 1.4 GHz bandwidth with approximately 1400 frequency channels. The total weight is 7.5 kg and the power consumption is 5.5 Watts only. The very stable temperature conditions on SWAS allow longtime integrations at total observing times far above 100 hours still with radiometric performance. So far, the AOS- spectra have not been degraded by particle hits, particularly the CCD detector of the AOS does not exhibit any visible effect due to cosmic rays. SWAS has already observed many interstellar sources in our galaxy. Emission of water is seen to be very abundant, while signals of molecular oxygen seem to be too weak to be observable.

  12. Performance of a MEMS-based AO-OCT system using Fourier Reconstruction

    SciTech Connect

    Evans, J; Zawadzki, R; Jones, S; Olivier, S; Werner, J S

    2009-01-21

    Adaptive optics (AO) and optical coherence tomography (OCT) are powerful imaging modalities that, when combined, can provide high-resolution (3.5 {micro}m isotropic), 3-D images of the retina. The AO-OCT system at UC Davis has demonstrated the utility of this technology for microscopic, volumetric, in vivo retinal imaging. The current system uses an AOptix bimorph deformable mirror (DM) for low-order, high-stroke correction and a 140-actuator Boston Micromachines DM for high-order correction. Developments to improve performance or functionality of the instrument are on-going. Based on previous work in system characterization we have focused on improved AO control. We present preliminary results and remaining challenges for a newly implemented Fourier transform reconstructor (FTR). The previously reported error budget analysis is also reviewed and updated, with consideration of how to improve both the amount of residual error and the robustness of the system. Careful characterization of the AO system will lead to improved performance and inform the design of future systems.

  13. GPS-Based Navigation And Orbit Determination for the AMSAT AO-40 Satellite

    NASA Technical Reports Server (NTRS)

    Davis, George; Moreau, Michael; Carpenter, Russell; Bauer, Frank

    2002-01-01

    The AMSAT OSCAR-40 (AO-40) spacecraft occupies a highly elliptical orbit (HEO) to support amateur radio experiments. An interesting aspect of the mission is the attempted use of GPS for navigation and attitude determination in HEO. Previous experiences with GPS tracking in such orbits have demonstrated the ability to acquire GPS signals, but very little data were produced for navigation and orbit determination studies. The AO-40 spacecraft, flying two Trimble Advanced Navigation Sensor (TANS) Vector GPS receivers for signal reception at apogee and at perigee, is the first to demonstrate autonomous tracking of GPS signals from within a HEO with no interaction from ground controllers. Moreover, over 11 weeks of total operations as of June 2002, the receiver has returned a continuous stream of code phase, Doppler, and carrier phase measurements useful for studying GPS signal characteristics and performing post-processed orbit determination studies in HEO. This paper presents the initial efforts to generate AO-40 navigation solutions from pseudorange data reconstructed from the TANS Vector code phase, as well as to generate a precise orbit solution for the AO-40 spacecraft using a batch filter.

  14. Improvement of phase diversity algorithm for non-common path calibration in extreme AO context

    NASA Astrophysics Data System (ADS)

    Robert, Clélia; Fusco, Thierry; Sauvage, Jean-François; Mugnier, Laurent

    2008-07-01

    Exoplanet direct imaging with a ground-based telescope needs a very high performance adaptive optics (AO) system, so-called eXtreme AO (XAO), a coronagraph device, and a smart imaging process. One limitation of AO system in operation remains the Non Common Path Aberrations (NCPA). To achieve the ultimate XAO performance, these aberrations have to be measured with a dedicated wavefront sensor placed in the imaging camera focal plane, and then pre-compensated using the AO closed loop process. In any events, the pre-compensation should minimize the aberrations at the coronagraph focal plane mask. An efficient way for the NCPA measurement is the phase diversity technique. A pixel-wise approach is well-suited to estimate NCPA on large pupils and subsequent projection on the deformable mirror with Cartesian geometry. However it calls for a careful regularization for optimal results. The weight of the regularization is written in close-form for un-supervised tuning. The accuracy of NCPA pre-compensation is below 8 nm for a wide range of conditions. Point-by-point phase estimation improves the accuracy of the Phase Diversity method. The algorithm is validated in simulation and experimentally. It will be implemented in SAXO, the XAO system of the second generation VLT instrument: SPHERE.

  15. An Infrared Optimized AO System for a 15 - 20m Class Telescope

    NASA Astrophysics Data System (ADS)

    Brandl, Bernhard R.; Eikenberry, Stephen S.; Herter, Terry L.; Kulkarni, Jayant

    2003-02-01

    Despite the relatively large number of proposed 'extremely large telescopes' very few of them concentrate on the thermal infrared as their main operating wavelengths. An IR-optimized large telescope located in the Atacama dessert at about 5500m altitude, where many atmospheric windows in the mid-IR open up, would be ideal to study astronomical targets that are either intrinsically red or heavily obscured by dust. A large aperture in the order of 15 - 20m requires adaptive optics correction out to λ<= 20 μm with the least possible thermal emission from the instrument itself. Here we discuss a specialized, integrated AO system that provides diffraction-limited performance in the thermal infrared (at λ>=2.5 μm). This approach is very different from the AO systems proposed for other 10m+ class telescopes. We present the basic concept of such an IR-optimized AO system, based on a 2m chopping adaptive secondary. We derive its technical specifications: configuration, bandwidth, and degrees of freedom show its predicted performance for typical seeing in terms of Strehl ratio as a function of limiting guide star magnitude, wavelength and corrected field-of-view. We also briefly address the science that this AO system/telescope would be ideal for.

  16. Outcome of Surgical Treatment of AO Type C Pelvic Ring Injury

    PubMed Central

    Moon, Do Hyeon; Kim, Nam Ki; Won, Jun Sung; Kim, Dong Hyun

    2014-01-01

    Purpose To evaluate the radiologic and clinical outcomes of AO type C pelvic ring injury and identify the prognostic factors. Materials and Methods We studied 53 patients who were treated for AO type C pelvic ring injury from January 2002 to February 2010. Mean age and mean follow-up duration were 42.4 years and 14 months, respectively. We had 8 cases of AO type C1-1, 19 cases of C1-2, 11 cases of C1-3, 6 cases of C2 and 9 cases of C3 injury. We analyzed type of fracture, displacement, method of fixation and associated injuries. Radiologic outcome was evaluated with Matta and Saucedo criteria and clinical outcome was evaluated using Majeed score. Results The average Majeed score was 86.2 distributing as 36 excellent cases, 15 good cases and 2 fair cases. Using radiologic Matta and Saucedo criteria, patients were divided as 31 excellent cases, 17 good cases and 5 fair cases. There was no significant difference between the outcomes of anterior, posterior and antero-posterior fixation. Neurologic injury was the reason for an unsatisfactory functional outcome. We identified two cases with complication, one with postoperative infection and the other with nonunion following anterior-posterior fixation. Conclusion Satisfactory radiologic and clinical outcomes were obtained with open reduction and internal fixation in the management of AO type C pelvic ring injuries. Neurologic injuries affected the clinical outcome.

  17. Improved tilt sensing in an LGS-based tomographic AO system based on instantaneous PSF estimation

    NASA Astrophysics Data System (ADS)

    Veran, Jean-Pierre

    2013-12-01

    Laser guide star (LGS)-based tomographic AO systems, such as Multi-Conjugate AO (MCAO), Multi-Object AO (MOAO) and Laser Tomography AO (LTAO), require natural guide stars (NGSs) to sense tip-tilt (TT) and possibly other low order modes, to get rid of the LGS-tilt indetermination problem. For example, NFIRAOS, the first-light facility MCAO system for the Thirty Meter Telescope requires three NGSs, in addition to six LGSs: two to measure TT and one to measure TT and defocus. In order to improve sky coverage, these NGSs are selected in a so-called technical field (2 arcmin in diameter for NFIRAOS), which is much larger than the on-axis science field (17x17 arcsec for NFIRAOS), on which the AO correction is optimized. Most times, the NGSs are far off-axis and thus poorly corrected by the high-order AO loop, resulting in spots with low contrast and high speckle noise. Accurately finding the position of such spots is difficult, even with advanced methods such as matched-filtering or correlation, because these methods rely on the knowledge of an average spot image, which is quite different from the instantaneous spot image, especially in case of poor correction. This results in poor tilt estimation, which, ultimately, impacts sky coverage. We propose to improve the estimation of the position of the NGS spots by using, for each frame, a current estimate of the instantaneous spot profile instead of an average profile. This estimate can be readily obtained by tracing wavefront errors in the direction of the NGS through the turbulence volume. The latter is already computed by the tomographic process from the LGS measurements as part of the high order AO loop. Computing such a wavefront estimate has actually already been proposed for the purpose of driving a deformable mirror (DM) in each NGS WFS, to optically correct the NGS spot, which does lead to improved centroiding accuracy. Our approach, however, is much simpler, because it does not require the complication of extra DMs

  18. 76 FR 52972 - United States v. Regal Beloit Corp. and A.O. Smith Corp.; Proposed Final Judgment and Competitive...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-24

    ... Columbia in United States v. Regal Beloit Corporation. and A.O. Smith Corporation., Civil Action No. 1:11... acquisition by Regal Beloit Corporation (``RBC'') of the electric motor business of A.O. Smith Corporation...., Suite 8700, Washington, DC 20530, Plaintiff, v. Regal Beloit Corporation, 200 State Street,...

  19. Safety evaluation of pectin-derived acidic oligosaccharides (pAOS): genotoxicity and sub-chronic studies.

    PubMed

    Garthoff, Jossie A; Heemskerk, Suzanne; Hempenius, Rixta A; Lina, Ben A R; Krul, Cyrille A M; Koeman, Jan H; Speijers, Gerrit J A

    2010-06-01

    Pectin-derived acidic oligosaccharides (pAOS) are non-digestible carbohydrates to be used in infant formulae and medical nutrition. To support its safety, the genotoxic potential of pAOS was evaluated. pAOS was not mutagenic in the Ames test. Positive results were obtained in the chromosome aberration test only at highly cytotoxic concentrations. The effects obtained in the mouse lymphoma test were equivocal; pAOS was not mutagenic in vivo. A sub-chronic dietary study, preceded by 4-week parental and in utero exposure phase, investigated general safety. Administration of pAOS did not affect parental health nor pup characteristics. No effects specific for acidic oligosaccharides were observed in the subsequent sub-chronic study. Slight diffuse hyperplasia of epithelial layer of the urinary bladder was noted to result from concurrently elevated urinary sodium, due to high sodium in pAOS, and elevated urinary pH. This phenomenon was confirmed in a mechanistic (sub-chronic) study. In contrast, in rats fed pAOS in combination with NH(4)Cl, an acidifying agent, the induced low urinary pH completely prevented the development of urothelial hyperplasia. Hyperplasia induced by this mechanism in rats is considered not relevant to man. Based on the current knowledge we consider pAOS safe for human consumption under its intended use. PMID:20026148

  20. The 384-channel prototype of DM Electronics for ELT AO systems

    NASA Astrophysics Data System (ADS)

    Caputa, Kris; Atwood, Jenny; Herriot, Glen; Veran, Jean-Pierre; Spanò, Paolo; Zielinski, Adam

    2014-08-01

    High order AO subsystems of the ELT require technological advancements in the Deformable Mirror (DM) construction and corresponding improvements in the drive electronics. Advanced prototyping is currently under way at NSI-Herzberg to reduce risks of deploying untried technology in the TMT AO subsystem NFIRAOS. We have developed a 96-channel output module and constructed a sub-scale DM Electronics prototype NDME384 with 384 output channels based on 4 such modules. French DM vendor Cilas has fabricated the NFIRAOS DM Breadoboard with 360 piezoelectric actuators in a 60×6 matrix, to demonstrate the DM technology to be deployed in NFIRAOS wavefront correctors. We present the results of testing our NDME384 prototype while driving the NFIRAOS DM Breadoboard.

  1. CANARY phase B: on-sky open-loop tomographic LGS AO results

    NASA Astrophysics Data System (ADS)

    Morris, Tim; Gendron, Eric; Basden, Alastair; Martin, Olivier; Osborn, James; Henry, David; Hubert, Zoltan; Sivo, Gaetano; Gratadour, Damien; Chemla, Fanny; Sevin, Arnaud; Cohen, Matthieu; Younger, Eddy; Vidal, Fabrice; Wilson, Richard; Butterley, Tim; Bitenc, Urban; Reeves, Andrew; Bharmal, Nazim; Raynaud, Henri-François; Kulcsar, Caroline; Conan, Jean-Marc; Huet, Jean-Michel; Perret, Denis; Dickson, Colin; Atkinson, David; Bailie, Tom; Longmore, Andy; Todd, Stephen; Talbot, Gordon; Morris, Simon; Rousset, Gérard; Myers, Richard

    2014-07-01

    CANARY is an on-sky Laser Guide Star (LGS) tomographic AO demonstrator that has been in operation at the 4.2m William Herschel Telescope (WHT) in La Palma since 2010. In 2013, CANARY was upgraded from its initial configuration that used three off-axis Natural Guide Stars (NGS) through the inclusion of four off-axis Rayleigh LGS and associated wavefront sensing system. Here we present the system and analysis of the on-sky results obtained at the WHT between May and September 2014. Finally we present results from the final `Phase C' CANARY system that aims to recreate the tomographic configuration to emulate the expected tomographic AO configuration of both the AOF at the VLT and E-ELT.

  2. Identification and calibration of the interaction matrix parameters for AO and MCAO systems

    NASA Astrophysics Data System (ADS)

    Neichel, Benoit; Parisot, Amelie; Petit, Cyril; Fusco, Thierry; Rigaut, François

    2012-07-01

    New tomographic Adaptive Optics (AO) concepts require a good knowledge of the system geometry and characteristics. These parameters are used to feed the tomographic reconstructors. In this paper we present a method to precisely identify the parameters required to construct an accurate synthetic set of models such as inuence functions, mis-registrations, directions of analysis or altitude of the DMs. The method is based on a multiparameter t of the interaction matrix. This identication method nds also its application in high contrast AO systems, such as SPHERE : in that case it is used as a diagnostic tool in order to precisely realign the system. The method has been tested and successfully implemented on HOMER, SPHERE and GeMS. Experimental results for these three systems are presented.

  3. Efficient control schemes with limited computation complexity for Tomographic AO systems on VLTs and ELTs

    NASA Astrophysics Data System (ADS)

    Petit, C.; Le Louarn, M.; Fusco, T.; Madec, P.-Y.

    2011-09-01

    Various tomographic control solutions have been proposed during the last decades to ensure efficient or even optimal closed-loop correction to tomographic Adaptive Optics (AO) concepts such as Laser Tomographic AO (LTAO), Multi-Conjugate AO (MCAO). The optimal solution, based on Linear Quadratic Gaussian (LQG) approach, as well as suboptimal but efficient solutions such as Pseudo-Open Loop Control (POLC) require multiple Matrix Vector Multiplications (MVM). Disregarding their respective performance, these efficient control solutions thus exhibit strong increase of on-line complexity and their implementation may become difficult in demanding cases. Among them, two cases are of particular interest. First, the system Real-Time Computer architecture and implementation is derived from past or present solutions and does not support multiple MVM. This is the case of the AO Facility which RTC architecture is derived from the SPARTA platform and inherits its simple MVM architecture, which does not fit with LTAO control solutions for instance. Second, considering future systems such as Extremely Large Telescopes, the number of degrees of freedom is twenty to one hundred times bigger than present systems. In these conditions, tomographic control solutions can hardly be used in their standard form and optimized implementation shall be considered. Single MVM tomographic control solutions represent a potential solution, and straightforward solutions such as Virtual Deformable Mirrors have been already proposed for LTAO but with tuning issues. We investigate in this paper the possibility to derive from tomographic control solutions, such as POLC or LQG, simplified control solutions ensuring simple MVM architecture and that could be thus implemented on nowadays systems or future complex systems. We theoretically derive various solutions and analyze their respective performance on various systems thanks to numerical simulation. We discuss the optimization of their performance and

  4. World-wide deployment of Robo-AO visible-light robotic laser adaptive optics systems

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Riddle, Reed; Law, Nicholas Michael; Lu, Jessica R.; Tonry, John; Tully, R. Brent; Wright, Shelley; Kulkarni, Shrinivas; Severson, Scott; Choi, Philip; Ramaprakash, A.; Chun, Mark; Connelley, Mike; Tokunaga, Alan; Hall, Donald

    2015-08-01

    In the next few years, several modest-sized telescopes around the world will be upgraded with autonomous laser adaptive optics systems based on the Robo-AO prototype deployed at the Palomar Observatory 1.5-m telescope. The prototype commenced scientific operations in June 2012 and more than 19,000 observations have since been performed at the ~0.12" visible-light diffraction limit. We are planning to move the prototype system to the 2.1-m telescope at Kitt Peak for a 3-year deployment which will serve a consortium of users including Caltech, the University of Hawai`i, IUCAA, NCU and institutions in China. Additionally, 2 months per year will be made available to the US astronomical community.New Robo-AO systems are in various stages of development: a clone by IUCAA for the 2-m IGO telescope in India; a natural guide star variant, KAPAO, by Pomona College at the 1-m Table Mountain telescope in California; and second generation Robo-AO systems are planned for the 3-m IRTF and 2.2-m University of Hawai'i telescopes on Maunakea, Hawai`i. The latter will exploit Maunakea's excellent observing conditions to provide higher Strehl ratios, sharper imaging, ~0.07", and correction to lambda = 400 nm. An additional infrared integral-field spectrograph will be fed by the UH 2.2-m Robo-AO system to quickly classify transients, such as supernovae and asteroids, discovered by the ATLAS system in Hawai`i.

  5. Real-time control for the high order, wide field DRAGON AO test bench

    NASA Astrophysics Data System (ADS)

    Basden, Alastair; Bharmal, Nazim A.; Bitenc, Urban; Dipper, Nigel; Morris, Tim; Myers, Richard; Reeves, Andrew; Younger, Eddy

    2014-07-01

    DRAGON is a high order, wide field AO test-bench at Durham. A key feature of DRAGON is the ability to be operated at real-time rates, i.e. frame rates of up to 1kHz, with low latency to maintain AO performance. Here, we will present the real-time control architecture for DRAGON, which includes two deformable mirrors, eight wavefront sensors and thousands of Shack-Hartmann sub-apertures. A novel approach has been taken to allow access to the wavefront sensor pixel stream, reducing latency and peak computational load, and this technique can be implemented for other similar wavefront sensor cameras with no hardware costs. We report on experience with an ELT-suitable wavefront sensor camera. DRAGON will form the basis for investigations into hardware acceleration architectures for AO real-time control, and recent work on GPU and many-core systems (including the Xeon Phi) will be reported. Additionally, the modular structure of DRAGON, its remote control capabilities, distribution of AO telemetry data, and the software concepts and architecture will be reported. Techniques used in DRAGON for pixel processing, slope calculation and wavefront reconstruction will be presented. This will include methods to handle changes in CN2 profile and sodium layer profile, both of which can be modelled in DRAGON. DRAGON software simulation techniques linking hardware-in-the-loop computer models to the DRAGON real-time system and control software will also be discussed. This tool allows testing of the DRAGON system without requiring physical hardware and serves as a test-bed for ELT integration and verification techniques.

  6. Inter- and intra-observer agreement of the AO classification for operatively treated distal radius fractures.

    PubMed

    van Buijtenen, Jesse M; van Tunen, Mischa L C; Zuidema, Wietse P; Heilbron, Emile A; de Haan, Jeroen; de Vet, Henrica C W; Derksen, Robert J

    2015-11-01

    The reproducibility of the AO classification for distal radius fractures remains a topic of debate. Previous studies showed variable reproducibility results. Important treatment decisions depend on correct classification, especially in comminuted, intra-articular fractures. Therefore, reliable reproducibility results need to be undisputedly determined. Hence, the study objective was to assess inter- and intra-observer agreement of the AO classification for operatively treated distal radius fractures. A database of 54 radiographs of all AO types (A, B and C) and groups (A2-3, B1-3, and C1-3) of distal radius fractures was assessed in twofold. Likewise, a subset of 152 radiographs of solely C-type groups (C1-3) was assessed. All fractures were classified by six observers with different experience levels: three consultant trauma surgeons, one sixth-year trauma surgery resident, a consultant trauma radiologist, and an intern with limited experienced. The inter-observer agreement of both main types and groups was moderate (κ = 0.49 resp. κ = 0.48) in combination with a good intra-observer agreement (κ = 0.68 resp. κ = 0.70). The inter-observer agreement of the subset C-type fractures group was fair (κ = 0.27) with moderate intra-observer agreement (κ = 0.43). According to these results, the reproducibility of the AO classification of main types and groups of distal radius fractures based on conventional radiographs is insufficient (κ < 0.50), especially at group level of C-type fractures. PMID:26614083

  7. Enabling technologies for visible adaptive optics: the Magellan adaptive secondary VisAO camera

    NASA Astrophysics Data System (ADS)

    Kopon, Derek; Males, Jared; Close, Laird M.; Gasho, Victor

    2009-08-01

    Since its beginnings, diffraction-limited ground-based adaptive optics (AO) imaging has been limited to wavelengths in the near IR (λ>1μm) and longer. Visible AO (λ>1μm) has proven to be difficult because shorter wavelengths require wavefront correction on very short spatial and temporal scales. The pupil must be sampled very finely, which requires dense actuator spacing and fine wavefront sampling with large dynamic range. In addition, atmospheric dispersion is much more significant in the visible than in the near-IR. Imaging over a broad visible band requires a very good Atmospheric Dispersion Corrector (ADC). Even with these technologies, our AO simulations using the CAOS code, combined with the optical and site parameters for the 6.5m Magellan telescope, demonstrate a large temporal variability of visible (λ=0.7μm) Strehl on timescales of 50 ms. Over several hundred milliseconds, the visible Strehl can be as high at 50% and as low as 10%. Taking advantage of periods of high Strehl requires either the ability to read out the CCD very fast, thereby introducing significant amounts of read-noise, or the use of a fast asynchronous shutter that can block the low-Strehl light. Our Magellan VisAO camera will use an advanced ADC, a high-speed shutter, and our 585 actuator adaptive secondary to achieve broadband (0.5-1.0 μm) diffraction limited images on the 6.5m Magellan Clay telescope in Chile at Las Campanas Observatory. These will be the sharpest and deepest visible direct images taken to date with a resolution of 17 mas, a factor of 2.7 better than the diffraction limit of the Hubble Space Telescope.

  8. AO/NAO Response to Climate Change. 1; Respective Influences of Stratospheric and Tropospheric Climate Changes

    NASA Technical Reports Server (NTRS)

    Rind, D.; Perlwitz, J.; Lonergan, P.

    2005-01-01

    We utilize the GISS Global Climate Middle Atmosphere Model and 8 different climate change experiments, many of them focused on stratospheric climate forcings, to assess the relative influence of tropospheric and stratospheric climate change on the extratropical circulation indices (Arctic Oscillation, AO; North Atlantic Oscillation, NAO). The experiments are run in two different ways: with variable sea surface temperatures (SSTs) to allow for a full tropospheric climate response, and with specified SSTs to minimize the tropospheric change. The results show that tropospheric warming (cooling) experiments and stratospheric cooling (warming) experiments produce more positive (negative) AO/NAO indices. For the typical magnitudes of tropospheric and stratospheric climate changes, the tropospheric response dominates; results are strongest when the tropospheric and stratospheric influences are producing similar phase changes. Both regions produce their effect primarily by altering wave propagation and angular momentum transports, but planetary wave energy changes accompanying tropospheric climate change are also important. Stratospheric forcing has a larger impact on the NAO than on the AO, and the angular momentum transport changes associated with it peak in the upper troposphere, affecting all wavenumbers. Tropospheric climate changes influence both the A0 and NAO with effects that extend throughout the troposphere. For both forcings there is often vertical consistency in the sign of the momentum transport changes, obscuring the difference between direct and indirect mechanisms for influencing the surface circulation.

  9. Microwelding of various metallic materials under ultravacuum (AO 138-10)

    NASA Technical Reports Server (NTRS)

    Assie, Jean Pierre; Conde, Eric

    1991-01-01

    The first finding from the AO 138-10 is that cold welding never occurred, and that microwelds didn't even affect the reference (presumably microweld prone) pairs of metals consisting of gold, silver, and chromium. The scientific disappointment from these results must be tempered by the notion of a static AO 138-10 experiment, reflecting the passive character of the global Long Duration Exposure Facility (LDEF) flight. Thus far, it has been theorized that cold welding results from the peeling of the oxide layer, that is formed in an earth environment, by the space environment since such a layer no longer grows in space. In fact, such stripping of the oxide layer supposes relative motion of the contacting materials. In the absence of such motion, as in this experiment, oxidation will preserve its integrity and continue to prevent microwelding. More bewildering is that there was no microwelding of the reference pairs. Even though AO 138-10 failed scientific expectations, as did the LDEF structure with cold welding, the positive, functional aspect to keep in mind is the safe operation of single-shot (appendage releasing and/or latching) mechanisms, unhindered by microwelding in a space vacuum, as now demonstrated by the statically representative pairs of materials. Other aspects of the experiment are discussed.

  10. AO modelling for wide-field E-ELT instrumentation using Monte-Carlo simulation

    NASA Astrophysics Data System (ADS)

    Basden, Alastair; Morris, Simon; Morris, Tim; Myers, Richard

    2014-08-01

    Extensive simulations of AO performance for several E-ELT instruments (including EAGLE, MOSAIC, HIRES and MAORY) have been ongoing using the Monte-Carlo Durham AO Simulation Package. We present the latest simulation results, including studies into DM requirements, dependencies of performance on asterism, detailed point spread function generation, accurate telescope modelling, and studies of laser guide star effects. Details of simulations will be given, including the use of optical models of the E-ELT to generate wave- front sensor pupil illumination functions, laser guide star modelling, and investigations of different many-layer atmospheric profiles. We discuss issues related to ELT-scale simulation, how we have overcome these, and how we will be approaching forthcoming issues such as modelling of advanced wavefront control, multi-rate wavefront sensing, and advanced treatment of extended laser guide star spots. We also present progress made on integrating simulation with AO real-time control systems. The impact of simulation outcomes on instrument design studies will be discussed, and the ongoing work plan presented.

  11. SCExAO: the most complete instrument to characterize exoplanets and stellar environments

    NASA Astrophysics Data System (ADS)

    Lozi, Julien; Guyon, Olivier; Jovanovic, Nemanja; Singh, Garima; Doughty, Danielle; Pathak, Prashant; Goebel, Sean; Kudo, Tomoyuki

    2015-12-01

    The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument, currently under development for the Subaru Telescope, optimally combines state-of-the-art technologies to directly study exoplanets and stellar environments at the diffraction limit, both in visible and infrared light (0.6 to 2.4 um). The instrument already includes an ultra-fast visible pyramid wavefront sensor operating at 3.5 kHz, a 2k-actuator deformable mirror, a set of optimal coronagraphs that can work as close as 1 l/D, a low-order wavefront sensor, a high-speed speckle control, and two visible interferometric modules, VAMPIRES and FIRST. Stability of the wavefront correction has already been demonstrated on sky, and SCExAO is already producing scientific results. After the integration of the Integral Field Spectrograph (IFS) CHARIS and a Microwave Kinetic Inductance Detector (MKID) in 2016, SCExAO will be one of the most powerful and effective tools for characterizing exoplanets and disks.

  12. Using the Fingerprinting Method to Customize RTLS Based on the AoA Ranging Technique

    PubMed Central

    Jachimczyk, Bartosz; Dziak, Damian; Kulesza, Wlodek J.

    2016-01-01

    Real-time Locating Systems (RTLSs) have the ability to precisely locate the position of things and people in real time. They are needed for security and emergency applications, but also for healthcare and home care appliances. The research aims for developing an analytical method to customize RTLSs, in order to improve localization performance in terms of precision. The proposed method is based on Angle of Arrival (AoA), a ranging technique and fingerprinting method along with an analytically defined uncertainty of AoA, and a localization uncertainty map. The presented solution includes three main concerns: geometry of indoor space, RTLS arrangement, and a statistical approach to localization precision of a pair of location sensors using an AoA signal. An evaluation of the implementation of the customized RTLS validates the analytical model of the fingerprinting map. The results of simulations and physical experiments verify the proposed method. The research confirms that the analytically established fingerprint map is the valid representation of RTLS’ performance in terms of precision. Furthermore, the research demonstrates an impact of workspace geometry and workspace layout onto the RTLS’ performance. Moreover, the studies show how the size and shape of a workspace and the placement of the calibration point affect the fingerprint map. Withal, the performance investigation defines the most effective arrangement of location sensors and its influence on localization precision. PMID:27314354

  13. Using the Fingerprinting Method to Customize RTLS Based on the AoA Ranging Technique.

    PubMed

    Jachimczyk, Bartosz; Dziak, Damian; Kulesza, Wlodek J

    2016-01-01

    Real-time Locating Systems (RTLSs) have the ability to precisely locate the position of things and people in real time. They are needed for security and emergency applications, but also for healthcare and home care appliances. The research aims for developing an analytical method to customize RTLSs, in order to improve localization performance in terms of precision. The proposed method is based on Angle of Arrival (AoA), a ranging technique and fingerprinting method along with an analytically defined uncertainty of AoA, and a localization uncertainty map. The presented solution includes three main concerns: geometry of indoor space, RTLS arrangement, and a statistical approach to localization precision of a pair of location sensors using an AoA signal. An evaluation of the implementation of the customized RTLS validates the analytical model of the fingerprinting map. The results of simulations and physical experiments verify the proposed method. The research confirms that the analytically established fingerprint map is the valid representation of RTLS' performance in terms of precision. Furthermore, the research demonstrates an impact of workspace geometry and workspace layout onto the RTLS' performance. Moreover, the studies show how the size and shape of a workspace and the placement of the calibration point affect the fingerprint map. Withal, the performance investigation defines the most effective arrangement of location sensors and its influence on localization precision. PMID:27314354

  14. PHOTOMETRIC EVOLUTION OF SNe Ib/c 2004ao, 2004gk, AND 2006gi

    SciTech Connect

    Elmhamdi, Abouazza; Kordi, Ayman; Tsvetkov, Dmitry; Danziger, I. John

    2011-04-20

    Photometric observations of three core collapse supernovae (SNe 2004ao, 2004gk, and 2006gi), covering about 200 days of evolution, are presented and analyzed. The photometric behavior of the three objects is consistent with their membership in the envelope-stripped Type Ib/c class. Pseudobolometric light curves are constructed. The corresponding measured e-folding times are found to be faster compared to the {sup 56}Co decay (i.e., 111.3 days), suggesting that a proportion of {gamma}-rays increasing with time have escaped without thermalization, owing to the low-mass nature of the ejecta. SN 2006gi has almost identical post-maximum decline phase luminosities as SN 1999ex and found to be similar to both SNe 1999dn and 1999ex in terms of the quasi-bolometric shape, placing it among the fast decliner Ib objects. SN 2004ao appears to fit within the slow decliner Ib SNe. SNe 2004ao and 2004gk display almost identical luminosities in the [50-100] day time interval, similar to SN 1993J. A preliminary simplified {gamma}-ray deposition model is described and applied to the computed pseudobolometric light curves, allowing one to find a range in the ejecta and {sup 56}Ni masses. The optical and quasi-bolometric light curves and the B - V color evolution of SN 2004gk are found to show a sudden drop after day 150. Correlating this fact to dust formation is premature and requires further observational evidence.

  15. Adaptive Optics at Optical Wavelengths: Test Observations of Kyoto 3DII Connected to Subaru Telescope AO188

    NASA Astrophysics Data System (ADS)

    Matsubayashi, K.; Sugai, H.; Shimono, A.; Akita, A.; Hattori, T.; Hayano, Y.; Minowa, Y.; Takeyama, N.

    2016-09-01

    Adaptive optics (AO) enables us to observe objects with high spatial resolution, which is important in most astrophysical observations. Most AO systems are operational at near-infrared wavelengths but not in the optical range, because optical observations require a much higher performance to obtain the same Strehl ratio as near-infrared observations. Therefore, to enable AO-assisted observations at optical wavelengths, we connected the Kyoto Tridimensional Spectrograph II (Kyoto 3DII), which can perform integral field spectroscopy, to the second generation AO system of the Subaru Telescope (AO188). We developed a new beam-splitter that reflects light below 594 nm for the wavefront sensors of AO188 and transmits above 644 nm for Kyoto 3DII. We also developed a Kyoto 3DII mount at the Nasmyth focus of the Subaru Telescope. In test observations, the spatial resolution of the combined AO188–Kyoto 3DII was higher than that in natural seeing conditions, even at 6500 Å. The full width at half maximum of an undersampled (1.5 spaxels) bright guide star (7.0 mag in the V-band) was 0.″12.

  16. Closed-loop tomographic control on HOMER wide-field AO bench: experimental results and identification issues

    NASA Astrophysics Data System (ADS)

    Parisot, Amelie; Costille, Anne; Petit, Cyril; Fusco, Thierry

    2010-07-01

    Adaptive Optics (AO) has a limited corrected field of view because of the anisoplanatism effect. Wide Field AO (WFAO) concepts, such as Multi-Conjugate AO (MCAO), have been developed to overcome this limitation. These complex WFAO systems raise critical challenges such as tomographic control and calibrations. We present new results obtained in closed-loop configuration with the laboratory bench HOMER which is devoted to implementation and validation of these WFAO concepts in the perspective of future VLT/ELT AO systems. Turbulence is generated with rotating phase screens and multi-directional analysis is performed. Tomographic control relies on Linear Quadratic Gaussian control (LQG). The correction can be applied thanks to two Deformable Mirrors (DM). We also focus on calibration issues and models identification. We investigate in particular identification of relative geometry of the wave front sensors, DM altitude and asterism and its impact on performance.

  17. Increasing Efficiency at the NTF by Optimizing Model AoA Positioning

    NASA Technical Reports Server (NTRS)

    Crawford, Bradley L.; Spells, Courtney

    2006-01-01

    The National Transonic Facility (NTF) at NASA Langley Research Center (LaRC) is a national resource for aeronautical research and development. The government, military and private industries rely on the capability of this facility for realistic flight data. Reducing the operation costs and keeping the NTF affordable is essential for aeronautics research. The NTF is undertaking an effort to reduce the time between data points during a pitch polar. This reduction is being driven by the operating costs of a cryogenic facility. If the time per data point can be reduced, a substantial cost savings can be realized from a reduction in liquid nitrogen (LN2) consumption. It is known that angle-of-attack (AoA) positioning is the longest lead-time item between points. In January 2005 a test was conducted at the NTF to determine the cause of the long lead-time so that an effort could be made to improve efficiency. The AoA signal at the NTF originates from onboard instrumentation then travels through a number of different systems including the signal conditioner, digital voltmeter, and the data system where the AoA angle is calculated. It is then fed into a closed loop control system that sets the model position. Each process along this path adds to the time per data point affecting the efficiency of the data taking process. Due to the nature of the closed loop feed back AoA control and the signal path, it takes approximately 18 seconds to take one pitch pause point with a typical AoA increment. Options are being investigated to reduce the time delay between points by modifying the signal path. These options include: reduced signal filtering, using analog channels instead of a digital volt meter (DVM), re-routing the signal directly to the AoA control computer and implementing new control algorithms. Each of these has potential to reduce the positioning time and together the savings could be significant. These timesaving efforts are essential but must be weighed against

  18. Effects of The NAO/ao Fluctuations Upon Precipitation Over Sardinia In The 20th Century.

    NASA Astrophysics Data System (ADS)

    Delitala, A.

    The effects at regional scale of decadal fluctuation of the NAO/AO on the 20th cen- tury precipitation over Sardinia will be analyzed. Decadal variations of precipitation will initially be described, by use of the Standardized Anomaly Index (Katz &Glantz, 1986) based on two indicators: the cumulated precipitation (the classical approach) and the number of rainy days. A clear decreasing trend in the last two deacdes, statis- tically significant at the 1% level, will be highlighted. A short survey of connections with MSLP and 500hPA Geopotential Height fields will be used to give an overview of dependence of Sardinia (regional) precipitation on synoptic-scale and planetary scale features. In the following part, three different paradigms of the NAO/AO will be used: the classical two point obscillation, the PCA analysis of MSLP (Thompson &Wallace, 1998) and the centers of action approach (Machel et al., 1998). The results of the anal- ysis of the effects of NAO/AO (described in the former three ways) on precipitation will enable to discuss how such a teleconnection influences regional precipitation on this part of the Mediterranean. Statistical significance of each result will be provided during the presentation. Katz, R., Glantz, M., 1986. "Anatomy of a Rainfall Index". Mon. Wea. Rev., 114, 764-771. Mächel, M., Kapala, A., Flohn, H., 1998. "Behaviour of the Centers of Action above the Atlantic since 1881. Part I: Characteristics of seasonal and interannual Variability". Int. Jou. of Climatol., 18, 1-22. Thopson, D. W. J., Wallace, J. M., 1998. "The Arctic Oscillation signature in the wintertime geopotential height and temperature fields". Geoph. Res. Let., 25, 1297- 1300.

  19. LDEF (Prelaunch), AO135 : Effect of Space Exposure on Pyroelectric Infrared Detectors, Tray E05

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO135 : Effect of Space Exposure on Pyroelectric Infrared Detectors, Tray E05 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF. The Space Exposure on Pyroelectric Infrared Detectors Experiment (AO135) consist of twenty detectors of three different types of materials, lithium-tantalate, strontium-barium-niobate and triglycine-sulfide. The Pyroelectric infrered detector experiment is an integral part of the Active Optical System Component Experiment (S0050) that contains 136 test specimen and is located in a six (6) inch deep LDEF peripheral experiment tray. The experiment tray is divided into six sections, each consisting of a 1/4 inch thick chromic anodized aluminum base plate and a 1/16th inch thick aluminum hat shaped structure for mounting the test specimen. The test specimen are typi- cally placed in fiberglass-epoxy retainer strip assemblies prior to installation on the hat shaped mounting structure. Five of the six sections are covered by a 1/8 inch thick anodized aluminum sun screen with openings that allowed 56 percent transmission over the central region. Two subexperiments, The Optical Materials and UV Detectors Experiment (S0050-01) consist of 15 optical windows, filters and detectors and occupies one of the trays six sub-sections and The Optical Substrates and Coatings Experiment (S0050-02 ) that includes 12 substrates and coatings and a secondary experiment, The Holographic Data Storage Crystal Experiment (AO044) with four crystals, are also mounted in the integrated tray. The experiment structure was assembled with non-magnetic stainless steel fasteners.

  20. LDEF (Prelaunch), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The prelaunch photograph shows the two (2) clam shell type canisters in their closed position. The canister shells are made of aluminum sheet material with end caps of diecast aluminum. The baseplate and support structure are fabricated from 6000 series aluminum. Fasteners are non-magnetic stainless steel. The electrical box and the stainless steel tubing located on the baseplate protect the drive system wiring. The experiment contains a timing mechanism that provides the intelligence to open the canisters after the Orbiter has departed the area and any initial outgassing or offgassing has occurred.

  1. Monitoring Io volcanism with AO telescopes during and after the NH flyby

    NASA Astrophysics Data System (ADS)

    Marchis, F.; Spencer, J. R.; Lopes, R. M.; Davies, A. G.; Dumas, C.

    2007-12-01

    To support the New Horizons (NH) Jupiter encounter we monitored Io's volcanic activity using high angular resolution images in the near infrared (1-5 microns) provided by adaptive optics (AO) systems available on 8-10m class telescopes. We initiated the campaign on Feb. 25 2007 with data obtained with the VLT-Yepun telescope (ESO, Paranal, Chile), just before NH closest approach. We continued monitoring with the Gemini North telescope (Hawaii, USA). The last observation was taken on May 28 2007. Numerous active volcanoes are visible in the data but the Tvashtar eruption is by far the most energetic. Extremely high angular resolution data from NH revealed fine detail of the eruption, such as the presence of an active plume [1]. This volcano has an interesting past history. It was seen as a powerful eruption from Nov. 26 1999 during the Galileo I25 [2] flyby to Feb. 19 2001 from the ground [3]. It was dormant or below our ground-based limit of detection (T<330 K assuming an area of 460 km2) between Dec 2001 and May 2004 [4,5]. The re-awakening of the volcano was reported by Laver et al. [6] in April 2006 based on Keck Adaptive Optics (AO) observations. Our last Gemini AO observation taken on May 26 shows that Tvashtar was still very active. Based on the previous behavior of this volcano [7] it is very likely that the activity reported in 2007 is a continuation of the Tvashtar-2006 eruption. Other hot spots, such as Loki Patera, Pele, and a new hot spot located north of Loki Patera, were seen in our data. We will describe the global picture of Io's volcanic activity derived from our observations, comparing it with previous observations from the Galileo spacecraft and using ground-based AO. 1. Spencer et al., AGU, this session, 2007 2. McEwen et al., Science, 288, 1193-1198, 2000 3. Marchis et al. Icarus, 160, 124-131, 2002 4. Marchis et al., Icarus, 176, 1, 2005 5. Marchis et al., AGU Fall meeting, V33C-1483, 2004 6. Laver et al., Icarus, in press, 2006 7. Milazzo et

  2. LDEF (Postflight), AO180 : The Effect of Space Environment Exposure on the Properties of Polymer Mat

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO180 : The Effect of Space Environment Exposure on the Properties of Polymer Matrix Composite Materials, Tray D12 The postflight photograph was taken in the SAEF-II facility prior to removal of experiment trays from the LDEF. The Polymer Matrix Composite Materials experiment appears the same as in the flight photograph. The composite containing the aramid (Kevlar) fibers has changed from a yellow to a light brown color and the cylinderical tubes containing the boron and carbon fiber materials have changed from a light green tint to a brown color. The experiment mounting hardware and fasteners seem to be intact and in very good condition.

  3. Optical Photometry of the flaring gamma-ray blazar AO 0235+164

    NASA Astrophysics Data System (ADS)

    Pursimo, Tapio; Losada, Illa R.; Messa, Matteo; Gafton, Emanuel; Ojha, Roopesh

    2016-03-01

    We report optical photometry of the blazar AO 0235+164 obtained with the 2.56m Nordic Optical Telescope in La Palma to look for any enhanced optical activity associated with a recent flare in the daily averaged gamma-ray flux seen in the public lightcurve of the Fermi/LAT instrument: http://fermi.gsfc.nasa.gov/FTP/glast/data/lat/catalogs/asp/current/lightcurves/0235+164_86400.png Fermi/LAT first reported a detection of gamma-ray activity from this source in Sep, 2008 (ATel#1744) and a short timescale flare in Oct 14, 2008 (ATel#1784).

  4. Tomographic separation of composite spectra - The components of the O-star spectroscopic binary AO Cassiopeiae

    NASA Technical Reports Server (NTRS)

    Bagnuolo, William G., Jr.; Gies, Douglas R.

    1991-01-01

    The UV photospheric lines of the short-period, double-lined O-star spectroscopic binary AO Cas are analyzed. Archival data from IUE (16 spectra uniformly distributed in orbital phase) were analyzed with a tomography algorithm to produce the separate spectra of the two stars in six spectral regions. The spectral classifications of the primary and secondary, O9.5 III and O8 V, respectively, were estimated through a comparison of UV line ratios with those in spectral standard stars. An intensity ratio of 0.5-0.7 (primary brighter) at 1600 A is compatible with the data.

  5. Preliminary results from the chemistry of micrometeoroid experiment (AO 187-1)

    NASA Technical Reports Server (NTRS)

    Horz, Friedrich; Bernhard, R. P.; See, Thomas H.; Warren, J.; Brownlee, Don E.; Laurance, M.

    1991-01-01

    The purpose of experiment AO 187-1 was to expose high purity substrates of suitable cratering properties to obtain detailed crater statistics that may be converted into projectile masses and fluxes and to chemically characterize as many impactors as possible. The latter information would hopefully reveal distinct classes of natural and man-made particles in low-Earth orbit. It was found that crater that yield residues show that natural and man-made impactors may be differentiated and that diversity exists within each group. 'Chondritic' compositions dominate among natural particles, yet some craters contain unmelted fragments of minerals (Olivine and pyroxene).

  6. The optical periodic analysis of BL Lac object AO 0235+164

    NASA Astrophysics Data System (ADS)

    Wang, Hongtao

    2014-05-01

    BL Lac object AO 0235+164 is a well-known object. We collect a large number of effective observation in B, V, R and I band from historical literatures. The possible periods are analyzed by means of discrete correlation function (DCF) method, structure function (SF) method and Jurkevich (J-K) method. The results show that there are possible periodic variations of 2.63-2.66 years in B band, 2.79-2.84 years in V band, 2.57-2.87 years in R band, 2.62-2.88 years in I band, respectively.

  7. LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1983-01-01

    LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00302 LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) on the LDEF. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminumized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of Experiment S1001 by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners.

  8. LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 EL-1994-00680 LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The flight photograph was taken with the LDEF on the Orbiter's RMS arm prior to berthing the spacecraft in the cargo bay. The canisters are in their open condition (they were expected to open about two (2) weeks after launch and close about eleven (11) months into the mission) with three (3) full panels and 3/4th of the fourth panel covered with a highly reflective gold foil (>99.99 percent pure).The remaining area is covered with strips of other detector materials: zirconium, beryllium, titanium, platium, aluminum, carbon, Kapton, polyethylene and TEFLON®. The exposed fasteners are non-magnetic stainless steel. All of the exposed materials seem to be secure and no damage is evident. The contamination stain that has changed the white paint dot on the tray clamp blocks to brown also coats the tray flanges and the aluminum canister hardware. The end support beam scuff plate in the photograph was a bright yellow prior to launch but is a much darker, mustard yellow after the space exposure.

  9. Tc-99m complexes of new functionalized propylene amine oxime (PnAO) ligands

    SciTech Connect

    Pillai, M.R.A.; Kothari, K.; Ramamoorthy, N.

    1994-05-01

    Three new functionalized PnAO ligands, 3,3,9,9-tetra-methyl-6-R-4, 8-diazaundecane-2,10-dionedioxime (R=benzyl, p-nitrobenzyl and p-aminobenzyl) were synthesised. Tc-99m complexes of these ligands were prepared by direct reduction of Tc-99m O{sub 4}{sup -} using stannous tartrate in the presence of ligands at pH 9.0. Complexation yields were greater than 95% at 1h and 24h post preparation as assessed by ITLC, HPLC and extraction into CHCl3. All three of the complexes were neutral and lipophilic (logP > 2.0) and eluted as single peak from a RP HPLC column. Biodistribution studies of the Tc-99m complexes of the benzyl and the nitrobenzyl derivatives were done in Wistar rats. Both complexes showed brain uptake but were washed out of the brain similar to the behavior of Tc-99m PnAO.

  10. Spiromastixones A-O, antibacterial chlorodepsidones from a deep-sea-derived Spiromastix sp. fungus.

    PubMed

    Niu, Siwen; Liu, Dong; Hu, Xinxin; Proksch, Peter; Shao, Zhongzhe; Lin, Wenhan

    2014-04-25

    Fifteen new depsidone-based analogues named spiromastixones A-O (1-15) were isolated from the fermentation broth of a deep-sea Spiromastix sp. fungus. Their structures were elucidated on the basis of extensive NMR and mass spectroscopic analysis in association with chemical conversion. Spiromastixones A-O are classified into two subtypes based on the orientation of ring C relative to ring A, while the n-propyl substituents on rings A and C are rarely seen in natural products. Most analogues are substituted by various numbers of chlorine atoms. All compounds exhibited significant inhibition against Gram-positive bacteria including Staphylococcus aureus, Bacillus thuringiensis, and Bacillus subtilis with MIC values ranging from 0.125 to 8.0 μg/mL. In addition, compounds 6-10 displayed potent inhibitory effects against methicillin-resistant bacterial strains of S. aureus (MRSA) and S. epidermidis (MRSE), while 10 also inhibited the growth of the vancomycin-resistant bacteria Enterococcus faecalis and E. faecium (VRE). The structure-activity relationships are discussed. PMID:24571273

  11. Risk Factors Associated with Campylobacter jejuni Infections in Curaçao, Netherlands Antilles

    PubMed Central

    Endtz, Hubert P.; van West, Hanneke; Godschalk, Peggy C. R.; de Haan, Lidewij; Halabi, Yaskara; van den Braak, Nicole; Kesztyüs, Barbara I.; Leyde, Ewald; Ott, Alewijn; Verkooyen, Roel; Price, Lawrence J.; Woodward, David L.; Rodgers, Frank G.; Ang, C. Wim; van Koningsveld, Rinske; van Belkum, Alex; Gerstenbluth, Izzy

    2003-01-01

    A steady increase in the incidence of Guillain-Barré syndrome (GBS) with a seasonal preponderance, almost exclusively related to Campylobacter jejuni, and a rise in the incidence of laboratory-confirmed Campylobacter enteritis have been reported from Curaçao, Netherlands Antilles. We therefore investigated possible risk factors associated with diarrhea due to epidemic C. jejuni. Typing by pulsed-field gel electrophoresis identified four epidemic clones which accounted for almost 60% of the infections. One hundred six cases were included in a case-control study. Infections with epidemic clones were more frequently observed in specific districts in Willemstad, the capital of Curaçao. One of these clones caused infections during the rainy season only and was associated with the presence of a deep well around the house. Two out of three GBS-related C. jejuni isolates belonged to an epidemic clone. The observations presented point toward water as a possible source of Campylobacter infections. PMID:14662945

  12. Closed-loop focal plane wavefront control with the SCExAO instrument

    NASA Astrophysics Data System (ADS)

    Martinache, Frantz; Jovanovic, Nemanja; Guyon, Olivier

    2016-09-01

    Aims: This article describes the implementation of a focal plane based wavefront control loop on the high-contrast imaging instrument SCExAO (Subaru Coronagraphic Extreme Adaptive Optics). The sensor relies on the Fourier analysis of conventional focal-plane images acquired after an asymmetric mask is introduced in the pupil of the instrument. Methods: This absolute sensor is used here in a closed-loop to compensate for the non-common path errors that normally affects any imaging system relying on an upstream adaptive optics system.This specific implementation was used to control low-order modes corresponding to eight zernike modes (from focus to spherical). Results: This loop was successfully run on-sky at the Subaru Telescope and is used to offset the SCExAO deformable mirror shape used as a zero-point by the high-order wavefront sensor. The paper details the range of errors this wavefront-sensing approach can operate within and explores the impact of saturation of the data and how it can be bypassed, at a cost in performance. Conclusions: Beyond this application, because of its low hardware impact, the asymmetric pupil Fourier wavefront sensor (APF-WFS) can easily be ported in a wide variety of wavefront sensing contexts, for ground- as well space-borne telescopes, and for telescope pupils that can be continuous, segmented or even sparse. The technique is powerful because it measures the wavefront where it really matters, at the level of the science detector.

  13. OCam with CCD220, the Fastest and Most Sensitive Camera to Date for AO Wavefront Sensing

    NASA Astrophysics Data System (ADS)

    Feautrier, Philippe; Gach, Jean-Luc; Balard, Philippe; Guillaume, Christian; Downing, Mark; Hubin, Norbert; Stadler, Eric; Magnard, Yves; Skegg, Michael; Robbins, Mark; Denney, Sandy; Suske, Wolfgang; Jorden, Paul; Wheeler, Patrick; Pool, Peter; Bell, Ray; Burt, David; Davies, Ian; Reyes, Javier; Meyer, Manfred; Baade, Dietrich; Kasper, Markus; Arsenault, Robin; Fusco, Thierry; Diaz Garcia, José Javier

    2011-03-01

    For the first time, subelectron readout noise has been achieved with a camera dedicated to astronomical wavefront-sensing applications. The OCam system demonstrated this performance at a 1300 Hz frame rate and with 240 × 240 pixel frame size. ESO and JRA2 OPTICON jointly funded e2v Technologies to develop a custom CCD for adaptive optics (AO) wavefront-sensing applications. The device, called CCD220, is a compact Peltier-cooled 240 × 240 pixel frame-transfer eight-output back-illuminated sensor using the EMCCD technology. This article demonstrates, for the first time, subelectron readout noise at frame rates from 25 Hz to 1300 Hz and dark current lower than 0.01 e- pixel-1 frame-1. It reports on the quantitative performance characterization of OCam and the CCD220, including readout noise, dark current, multiplication gain, quantum efficiency, and charge transfer efficiency. OCam includes a low-noise preamplifier stage, a digital board to generate the clocks, and a microcontroller. The data acquisition system includes a user-friendly timer file editor to generate any type of clocking scheme. A second version of OCam, called OCam2, has been designed to offer enhanced performance, a completely sealed camera package, and an additional Peltier stage to facilitate operation on a telescope or environmentally challenging applications. New features of OCam2 are presented in this article. This instrumental development will strongly impact the performance of the most advanced AO systems to come.

  14. The MeJA-inducible copper amine oxidase AtAO1 is expressed in xylem tissue and guard cells

    PubMed Central

    Ghuge, Sandip A; Carucci, Andrea; Rodrigues-Pousada, Renato A; Tisi, Alessandra; Franchi, Stefano; Tavladoraki, Paraskevi; Angelini, Riccardo; Cona, Alessandra

    2015-01-01

    Copper amine oxidases oxidize the polyamine putrescine to 4-aminobutanal with the production of the plant signal molecule hydrogen peroxide (H2O2) and ammonia. The Arabidopsis (Arabidopsis thaliana) gene At4g14940 (AtAO1, previously referred to as ATAO1) encodes an apoplastic copper amine oxidase expressed in lateral root cap cells and developing xylem, especially in root protoxylem and metaxylem precursors. In our recent study, we demonstrated that AtAO1 expression is strongly induced in the root vascular tissues by the wound-signal hormone methyl jasmonate (MeJA). Furthermore, we also demonstrated that the H2O2 derived by the AtAO1-driven oxidation of putrescine, mediates the MeJA–induced early protoxylem differentiation in Arabidopsis roots. H2O2 may contribute to protoxylem differentiation by signaling developmental cell death and by acting as co-substrate in peroxidase-mediated cell wall stiffening and lignin polymerization. Here, by the means of AtAO1 promoter::green fluorescent protein-β-glucuronidase (AtAO1::GFP-GUS) fusion analysis, we show that a strong AtAO1 gene expression occurs also in guard cells of leaves and flowers. The high expression levels of AtAO1 in tissues or cell types regulating water supply and water loss may suggest a role of the encoded protein in water balance homeostasis, by modulating coordinated adjustments in anatomical and functional features of xylem tissue and guard cells during acclimation to adverse environmental conditions. PMID:26241131

  15. The new Arecibo Observatory Remote Optical Facility (AO-ROF) in Culebra Island, Puerto Rico: Current Status and Future Projects

    NASA Astrophysics Data System (ADS)

    Santos, P. T.

    2015-12-01

    The idea of establishing the Arecibo Observatory Remote Optical Facility (AO-ROF) in the island of Culebra is a solution to mitigate the ever cumulative quantity of cloud, fog, and rain that has distressed observations at the Arecibo Observatory (AO) during major optical campaigns and observations. Given Culebra Island's favorable geographical and climatological characteristics as its low elevation and geographic location, it appears to have more steady weather conditions than Arecibo, so therefore it provides more availability for optical observations. Placed on Culebra, optical instruments can observe the same thermospheric volume over AO sampled by the Incoherent Scatter Radar (ISR). This capability will become especially important during the High Frequency (HF) facility is on operation. Small and large scale irregularities created by that HF can be readily observed and tracked from the Culebra site, and simultaneous observations from AO of the same atmospheric volume will permit direct vector measurements of dynamical evolution of the irregularities. This work presents a discussion of the current status of AO-ROF facility, as well the future projects.

  16. GOALS, STRATEGIES AND FIRST DISCOVERIES OF AO327, THE ARECIBO ALL-SKY 327 MHz DRIFT PULSAR SURVEY

    SciTech Connect

    Deneva, J. S.; Stovall, K.; Martinez, J. G.; Jenet, F.; McLaughlin, M. A.; Bates, S. D.; Bagchi, M.; Freire, P. C. C.

    2013-09-20

    We report initial results from AO327, a drift survey for pulsars with the Arecibo telescope at 327 MHz. The first phase of AO327 will cover the sky at declinations of –1° to 28°, excluding the region within 5° of the Galactic plane, where high scattering and dispersion make low-frequency surveys sub-optimal. We record data from a 57 MHz bandwidth with 1024 channels and 125 μs sampling time. The 60 s transit time through the AO327 beam means that the survey is sensitive to very tight relativistic binaries even with no acceleration searches. To date we have detected 44 known pulsars with periods ranging from 3 ms to 2.21 s and discovered 24 new pulsars. The new discoveries include 3 ms pulsars, three objects with periods of a few tens of milliseconds typical of young as well as mildly recycled pulsars, a nuller, and a rotating radio transient. Five of the new discoveries are in binary systems. The second phase of AO327 will cover the sky at declinations of 28°-38°. We compare the sensitivity and search volume of AO327 to the Green Bank North Celestial Cap survey and the GBT350 drift survey, both of which operate at 350 MHz.

  17. Interannual variations of the blocking high over the Ural Mountains and its association with the AO/NAO in boreal winter

    NASA Astrophysics Data System (ADS)

    Li, Chao; Zhang, Qingyun; Ji, Liren; Peng, Jingbei

    2012-04-01

    This paper analyzes interannual variations of the blocking high over the Ural Mountains in the boreal winter and their association with the Arctic Oscillation/North Atlantic Oscillation (AO/NAO). In January, the relationship between the Ural blocking high (UR) and the AO index is statistically significant. The UR tends to occur more frequently and with greater strength during negative AO periods. Some strong URs also occur during positive AO phases (positive UR-AO events), as in January 2008. This paper discusses the characteristics of atmospheric circulation in the cases of positive UR-AO events and contrast cases (negative UR-AO events). The eastward extending of the Icelandic Low (IL) center and the associated NAO dipole anomaly pattern in the upstream region may play a more important role for the UR-AO events. When the center of the IL shifts eastward to 30°W, the amplitude of zonal wavenumber 2 (wavenumber 3) is intensified in the positive (negative) UR-AO events, which favors positive (negative) height anomalies over the Urals. Further analyses indicate that the intensified zonal wind in high latitudes and weakened zonal wind in midlatitudes over the North Atlantic Ocean render the eastward shift of the IL and the NAO dipole anomaly pattern. The Ural blocking in January 2008 bears similar characteristics to the positive UR-AO events.

  18. LDEF (Postflight), AO187-02 : Chemical and Isotropic Measurements of Micrometeoroids by Secondary Io

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO187-02 : Chemical and Isotropic Measurements of Micrometeoroids by Secondary Ion Mass Spectrometry, Tray E08 This postflight photograph shows an experiment that has been severely degraded due to orbital exposure on the leading edge of the LDEF. The metallic coated thin Mylar film has been lost on each of the capture cells. As the thin Mylar film failed, the material curled tightly into small conical shapes and can be seen still attached to the aluminum mounting structure edges of many capture cells. Close examination of capture cells near the tray center clearly show the four individual high purity germanium plates with some of the bonding material exposed between plates. The green tint on the germanium plate at the right edge of the experiment tray is a reflection from the lights in the high bay area of SAEF II at KFC. Dim reflections from various sources can be seen on other sections of the experiment.

  19. Sub-rubble communities of Curaçao and Bonaire coral reefs

    NASA Astrophysics Data System (ADS)

    Meesters, E.; Knijn, R.; Willemsen, P.; Pennartz, R.; Roebers, G.; van Soest, R. W. M.

    1991-12-01

    The distribution and abundance of sessile organisms under coral rubble has been studied at Bonaire and Curaçao, Netherlands Antilles. Species richness under rubble is extremely high with at least 367 species of which sponges, tunicates and bryozoans are the most important. Shallow sub-rubble communities can be considered refuges as the majority of these species are crypt-obligate. Sub-rubble communities may also have a preserve function for sponges, but do not harbour enough corals to ensure a quick coral recolonization of the reef surface after a major disaster. Cryptic community composition is affected by depth and pollution, and differs substantially between the two neighbouring islands, possibly as a result of different bottom characteristics. Biomass of the sub-rubble communities may contribute considerably to total reef biomass. Diversity varies inversely with increased depth and increased rubble size, possibly indicating abiotic control (e.g. physical disturbance by wave action and reef slope substrate collapse).

  20. Analysis of Optical Variations of BL Lac Object AO 0235+164

    NASA Astrophysics Data System (ADS)

    Hong-tao, Wang

    2014-03-01

    Historical optical BVRI band data are combined on the BL Lac object AO 0235 + 164. In order to examine the possible existence of lags and correlations between variations in different optical bands from this source, a statistical analysis is performed through the Discrete Correlation Function (DCF) method. Monte Carlo simulations called Flux Redistribution/Random Subset Selection (FR/RSS) are performed to obtain statistically meaningful values for the cross-correlation time lags and their related uncertainties. The analysis confirms that the variations in different optical light curves are strongly correlated, with no or very weak lag within the errors. Long term variability of color indices are also analysed. No color variabilities are found.

  1. Selected Examples of Solar and Extra-Solar Planetary Science with AO

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Lenzen, Rainer; Biller, Beth; Brandner, Wolfgang; Hartung, Markus

    High spatial resolution planetary science has seen a large boost from AO observations complementing space missions. Adaptive optics is particularly well suited for planetary astronomy since solar system bodies have temporal behavior well suited to multiple epochs of observation. Here we will just highlight some very recent examples: Uranus's rings (de Pater et al. 2002), volcanoes on Io (Marchis et al. 2002), the surface of 3 Juno (Baliunas et al. 2003), and binary asteroids (Merline et al. 2002). In addition, we will present "first light" sensitivities from a high contrast simultaneous differential imager (SDI) device. This device (called NACO SDI) can detect an extrasolar planet 25,000 times fainter just 0.5" from its parent star in 40 min of VLT time at 6 sigma. These are the highest contrast astronomical images taken to date.

  2. Eutrophication threatens Caribbean seagrasses - An example from Curaçao and Bonaire.

    PubMed

    Govers, Laura L; Lamers, Leon P M; Bouma, Tjeerd J; de Brouwer, Jan H F; van Katwijk, Marieke M

    2014-12-15

    Seagrass beds are globally declining due to human activities in coastal areas. We here aimed to identify threats from eutrophication to the valuable seagrass beds of Curaçao and Bonaire in the Caribbean, which function as nursery habitats for commercial fish species. We documented surface- and porewater nutrient concentrations, and seagrass nutrient concentrations in 6 bays varying in nutrient loads. Water measurements only provided a momentary snapshot, due to timing, tidal stage, etc., but Thalassia testudinum nutrient concentrations indicated long-term nutrient loads. Nutrient levels in most bays did not raise any concern, but high leaf % P values of Thalassia in Piscadera Bay (∼0.31%) and Spanish Water Bay (∼0.21%) showed that seagrasses may be threatened by eutrophication, due to emergency overflow of waste water and coastal housing. We thus showed that seagrasses may be threatened and measures should be taken to prevent loss of these important nursery areas due to eutrophication. PMID:25256296

  3. LDEF (Flight), AO180 : The Effect of Space Environment Exposure on the Properties of Polymer Matrix

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO180 : The Effect of Space Environment Exposure on the Properties of Polymer Matrix Composite Materials, Tray D12 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval. During the mission, the tray surface was at an angle of approximately ninety-eight (98) degrees to the orbital velocity vector and therefore exposed to a lower atomic oxygen flux than if parallel with the velocity vector. A very light stain is present on white paint dots on experiment tray clamps along the lower edge of the tray. The Polymer Matrix Composite Materials experiment has several changes to material colors. The composite containing the aramid (Kevlar) fibers has changed from a yellow to a light brown color and the cylindrical tubes containing the boron and carbon fiber materials have changed from a light green tint to a brown color.

  4. Toward a large lightweight mirror for AO: development of a 1m Ni coated CFRP mirror

    NASA Astrophysics Data System (ADS)

    Thompson, S. J.; Doel, A. P.; Brooks, D.; Strangwood, M.

    2008-07-01

    We present our recent developments towards the construction of a large, thin, single-piece mirror for adaptive optics (AO). Our current research program aims to have completed fabrication and testing of a 1m diameter, nickel coated carbon-fibre reinforced cyanate ester resin mirror by the last quarter of 2009. This composite mirror material is being developed to provide a lightweight and robust alternative to thin glass shell mirrors, with the challenge of future large deformable mirrors such as the 2.5m M4 on the E-ELT in mind. A detailed analysis of the material properties of test mirror samples is being performed at the University of Birmingham (UK), the first results of which are discussed and presented here. We discuss the project progress achieved so far, including fabrication of the 1m flat moulds for the replication process, manufacturing and testing methods for 20 cm diameter sample mirrors and system simulations.

  5. ShaneAO: wide science spectrum adaptive optics system for the Lick Observatory

    NASA Astrophysics Data System (ADS)

    Gavel, Donald; Kupke, Renate; Dillon, Daren; Norton, Andrew; Ratliff, Chris; Cabak, Jerry; Phillips, Andrew; Rockosi, Connie; McGurk, Rosalie; Srinath, Srikar; Peck, Michael; Deich, William; Lanclos, Kyle; Gates, John; Saylor, Michael; Ward, Jim; Pfister, Terry

    2014-07-01

    A new high-order adaptive optics system is now being commissioned at the Lick Observatory Shane 3-meter telescope in California. This system uses a high return efficiency sodium beacon and a combination of low and high-order deformable mirrors to achieve diffraction-limited imaging over a wide spectrum of infrared science wavelengths covering 0.8 to 2.2 microns. We present the design performance goals and the first on-sky test results. We discuss several innovations that make this system a pathfinder for next generation AO systems. These include a unique woofer-tweeter control that provides full dynamic range correction from tip/tilt to 16 cycles, variable pupil sampling wavefront sensor, new enhanced silver coatings developed at UC Observatories that improve science and LGS throughput, and tight mechanical rigidity that enables a multi-hour diffraction-limited exposure in LGS mode for faint object spectroscopy science.

  6. Development and operation of an off-limb solar AO system

    NASA Astrophysics Data System (ADS)

    Taylor, Gregory Edward

    An Adaptive Optics system capable of locking-on to off-limb prominence structure has been proven successful. It has been shown to allow for diffraction limited spectroscopy and polarimetry of prominence structure. Spectroscopic data obtained using the Off-Limb AO system have been shown to contain a trove of information regarding the nature of solar prominences. In particular a Rayleigh-Taylor instability was seen in part of this data set. Such instabilities, and the rising plumes that result from them, are thought to be critical clues to the longterm persistence of quiescent solar prominences. This adaptive optics system will allow scientists to come one step closer to understanding the true nature of solar prominences.

  7. FlyEyes: integrating CCID-35 into PUEO AO system at CFHT

    NASA Astrophysics Data System (ADS)

    Ho, Kevin K. Y.; Cuillandre, Jean-Charles; Lin, Chueh-Jen; Benedict, Tom; Lai, Olivier; Ward, Jeff; Salmon, Derrick; Luppino, Gerry; Beletic, James; Dorn, Reinhold; Puget, Pascal; Burke, Barry; Wang, Shiang-Yu

    2006-06-01

    A project to upgrade PUEO, the CFHT AO system, was first proposed in 2002. As part of the upgrade effort, a technology project was conceived to evaluate and characterize the backside-illuminated CCID-35 detector as suitable a replacement for the array of avalanche photo diode modules (APDs) in the curvature wavefront sensor. The CCID-35 was envisioned to replace an array of expensive APDs thus providing a cost-effective means of upgrading PUEO to a higher-order system. Work on the project, dubbed FlyEyes, occurred sporadically until Oct 2005 but substantial progress has been made since. This paper was intended to report on the performance of FlyEyes in PUEO but unfortunately the instrument was not ready for tests at the time of this writing. This paper summarizes the progress made on the project thus far and touches upon some of the difficulties encountered.

  8. User perceptions on coastal resource state and management options in Curaçao.

    PubMed

    Debrot, A O; Nagelkerken, I

    2000-12-01

    Public environmental awareness and support for management measures are key determinants of the scope for successful implementation of natural resource management. To assess user perceptions and opinions on resource state and potential management options for the coastal zone of Curaçao, we queried 250 coastal resource users from around the island (sport divers, part-time artisanal fishermen and recreational boaters) using questionnaires. There is wide awareness of a long-term decline in coastal resource condition as measured by various indicators. Even among fishermen there was wide awareness of anthropogenic contributors to the decline, broad agreement of management measures required and a general willingness to contribute to management by means of annual license fees. Some of the more salient findings include the endorsement by fishermen of the current ban on spearfishing (81%), the regulation of the beach seine fishery for scad (77%), the introduction of fish reserves (72%), special protection for sea turtles (90%), conch (82%), and lobsters (72%), and notable support for gradual elimination of trap fisheries (45%). Also, both divers (65%) and boaters (92%) expressed the importance to them of an attractive coastline, with both groups expressing preference for natural (un-built) coastline (>74%) above other categories. Management based on the concept "user pays", as already implemented in the Netherlands Antilles on Saba and Bonaire, is well supported by the resource user public. A review of other main constraints such as finances and institutional capacity, shows that conditions are quite favorable for implementation of new legislation. Modem coral reef management is urgently needed in Curaçao to safeguard a key natural resource and concerted action is called for on the part of government agencies, legislators and elected officials. PMID:15266797

  9. Robotic laser adaptive optics imaging of 715 Kepler exoplanet candidates using Robo-AO

    SciTech Connect

    Law, Nicholas M.; Ziegler, Carl; Morton, Tim; Riddle, Reed; Tendulkar, Shriharsh P.; Bui, Khanh; Dekany, Richard G.; Kulkarni, Shrinivas; Punnadi, Sujit; Baranec, Christoph; Ravichandran, Ganesh; Johnson, John Asher; Burse, Mahesh P.; Das, H. K.; Ramaprakash, A. N.

    2014-08-10

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging to search for blended nearby stars, which may be physically associated companions and/or responsible for transit false positives. In this paper, we present the results from the 2012 observing season, searching for stars close to 715 Kepler planet candidate hosts. We find 53 companions, 43 of which are new discoveries. We detail the Robo-AO survey data reduction methods including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for large adaptive optics surveys. Our survey is sensitive to objects from ≈0.''15 to 2.''5 separation, with magnitude differences up to Δm ≈ 6. We measure an overall nearby-star probability for Kepler planet candidates of 7.4% ± 1.0%, and calculate the effects of each detected nearby star on the Kepler-measured planetary radius. We discuss several Kepler Objects of Interest (KOIs) of particular interest, including KOI-191 and KOI-1151, which are both multi-planet systems with detected stellar companions whose unusual planetary system architecture might be best explained if they are 'coincident multiple' systems, with several transiting planets shared between the two stars. Finally, we find 98% confidence evidence that short-period giant planets are two to three times more likely than longer-period planets to be found in wide stellar binaries.

  10. Interdecadal changes in the Asian winter monsoon variability and its relationship with ENSO and AO

    NASA Astrophysics Data System (ADS)

    Yun, Kyung-Sook; Seo, Ye-Won; Ha, Kyung-Ja; Lee, June-Yi; Kajikawa, Yoshiyuki

    2014-08-01

    Interdecadal changes in the Asian winter monsoon (AWM) variability are investigated using three surface air temperature datasets for the 55-year period of 1958-2012 from (1) the National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis 1 (NCEP), (2) combined datasets from the European Centre for Medium-range Weather Forecasts (ECMWF) 40-yr reanalysis and interim data (ERA), and (3) Japanese 55-year reanalysis (JRA). Particular attention has been paid to the first four empirical orthogonal function (EOF) modes of the AWM temperature variability that together account for 64% of the total variance and have been previously identified as predictable modes. The four modes are characterized as follows: the first mode by a southern warming over the Indo-western Pacific Ocean associated with a gradually increasing basin-wide warming trend; the second mode by northern warming with the interdecadal change after the late 1980s; the third and fourth modes by north-south triple pattern, which reveal a phase shift after the late 1970s. The three reanalyses agree well with each other when producing the first three modes, but show large discrepancy in capturing both spatial and temporal characteristics of the fourth mode. It is therefore considered that the first three leading modes are more reliable than the rest higher modes. Considerable interdecadal changes are found mainly in the first two modes. While the first mode shows gradually decreasing variance, the second mode exhibits larger interannual variance during the recent decade. In addition, after the late 1970s, the first mode has a weakening relationship with the El Niño-Southern Oscillation (ENSO) whereas the second mode has strengthening association with the Artic Oscillation (AO). This indicates an increasing role of AO but decreasing role of ENSO on the AWM variability. A better understanding of the interdecadal change in the dominant modes would contribute toward advancing in

  11. Bioremediation of bisphenol-A polluted soil by Sphingomonas bisphenolicum AO1 and the microbial community existing in the soil.

    PubMed

    Matsumura, Yoshinobu; Akahira-Moriya, Ayako; Sasaki-Mori, Miho

    2015-01-01

    Bisphenol A (BPA, 2,2'-Bis (4-hydroxyphenyl) propane) is an artificial pollutant that is easily detected in soil and water environments. BPA decomposition and removal from the environment is relatively difficult due to its stability. This study evaluated the BPA decomposition and removal activities of the microbial community existing in the soil with or without Sphingomonas bisphenolicum AO1, and revealed the toxic effects of BPA towards the microbial community. The microbial community in soil was able to degrade BPA at 1.0 mg·g(-1) soil or lower, although its degradation was slow. On the other hand, BPA at more than 10 mg·g(-1) soil was not only degraded by the microbial community but also decreased its diversity, suggesting that BPA is harmful to many microorganisms. PCR-TTGE analysis and the cloned 16S rRNA gene sequence analysis indicated that Sphingomonadales, Xanthomonadales, Burkholderiales and Pseudomonadales in the microbial community might independently or cooperatively degrade BPA. On the other hand, supplementation with strain AO1 was able to significantly improve the BPA decomposition activity of the microbial community in soil even at 10 mg BPA·g(-1) soil, although BPA at 100 mg·g(-1) soil overwhelmed the BPA decomposition activity of strain AO1. Furthermore, it was also concluded that strain AO1 could not inhabit BPA purified soil after decomposition of BPA by strain AO1 and the soil microbial community, suggesting that the application of strain AO1 could be a low-burden method for the decomposition and removal of BPA from the natural environment. PMID:25817811

  12. The Magellan Adaptive Secondary VisAO Camera: diffraction-limited broadband visible imaging and 20mas fiber array IFU

    NASA Astrophysics Data System (ADS)

    Kopon, Derek; Close, Laird M.; Males, Jared; Gasho, Victor; Follette, Katherine

    2010-07-01

    The Magellan Adaptive Secondary AO system, scheduled for first light in the fall of 2011, will be able to simultaneously perform diffraction limited AO science in both the mid-IR, using the BLINC/MIRAC4 10μm camera, and in the visible using our novel VisAO camera. The VisAO camera will be able to operate as either an imager, using a CCD47 with 8.5 mas pixels, or as an IFS, using a custom fiber array at the focal plane with 20 mas elements in its highest resolution mode. In imaging mode, the VisAO camera will have a full suite of filters, coronagraphic focal plane occulting spots, and SDI prism/filters. The imaging mode should provide ~20% mean Strehl diffraction-limited images over the band 0.5-1.0 μm. In IFS mode, the VisAO instrument will provide R~1,800 spectra over the band 0.6-1.05 μm. Our unprecedented 20 mas spatially resolved visible spectra would be the highest spatial resolution achieved to date, either from the ground or in space. We also present lab results from our recently fabricated advanced triplet Atmospheric Dispersion Corrector (ADC) and the design of our novel wide-field acquisition and active optics lens. The advanced ADC is designed to perform 58% better than conventional doublet ADCs and is one of the enabling technologies that will allow us to achieve broadband (0.5-1.0μm) diffraction limited imaging and wavefront sensing in the visible.

  13. Na+ Transport by the A1AO-ATP Synthase Purified from Thermococcus onnurineus and Reconstituted into Liposomes*

    PubMed Central

    Mayer, Florian; Lim, Jae Kyu; Langer, Julian D.; Kang, Sung Gyun; Müller, Volker

    2015-01-01

    The ATP synthase of many archaea has the conserved sodium ion binding motif in its rotor subunit, implying that these A1AO-ATP synthases use Na+ as coupling ion. However, this has never been experimentally verified with a purified system. To experimentally address the nature of the coupling ion, we have purified the A1AO-ATP synthase from T. onnurineus. It contains nine subunits that are functionally coupled. The enzyme hydrolyzed ATP, CTP, GTP, UTP, and ITP with nearly identical activities of around 40 units/mg of protein and was active over a wide pH range with maximal activity at pH 7. Noteworthy was the temperature profile. ATP hydrolysis was maximal at 80 °C and still retained an activity of 2.5 units/mg of protein at 45 °C. The high activity of the enzyme at 45 °C opened, for the first time, a way to directly measure ion transport in an A1AO-ATP synthase. Therefore, the enzyme was reconstituted into liposomes generated from Escherichia coli lipids. These proteoliposomes were still active at 45 °C and coupled ATP hydrolysis to primary and electrogenic Na+ transport. This is the first proof of Na+ transport by an A1AO-ATP synthase and these findings are discussed in light of the distribution of the sodium ion binding motif in archaea and the role of Na+ in the bioenergetics of archaea. PMID:25593316

  14. Ionic Polymer-Coated Laccase with High Activity and Enhanced Stability: Application in the Decolourisation of Water Containing AO7

    PubMed Central

    Zhang, Xiaolin; Hua, Ming; Lv, Lu; Pan, Bingcai

    2015-01-01

    Eliminating dyes in environmental water purification remains a formidable challenge. Laccase is a unique, environmentally friendly and efficient biocatalyst that can degrade pollutants. However, the use of laccase for the degradation of pollutants is considerably limited by its susceptibility to environmental changes and its poor reusability. We fabricated a novel biocatalyst (LacPG) by coating polyethylenimine onto the native laccase (Lac) followed by crosslinking with glutaraldehyde. The stability of the resulting LacPG was highly enhanced against pH variations, thermal treatments and provided better long-term storage with a negligible loss in enzymatic activity. Compared to Lac, LacPG exhibited significantly higher decolourisation efficiency in the degradation of a representative azo dye, acid orange 7 (AO7), which resulted from the electrostatic attraction between the coating and AO7. LacPG was separated from the AO7 solution using an ultrafiltration unit. The increased size and modified surface chemistry of LacPG facilitated ultrafiltration and reduced membrane fouling. LacPG exhibited enhanced stability, high catalytic activity and favourable properties for membrane separation; therefore, LacPG could be continuously reused in an enzymatic membrane reactor with a high efficiency for decolourising water containing AO7. The developed strategy appears to be promising for enhancing the applicability of laccase in practical water treatment. PMID:25652843

  15. Project summary: Emerging technology assessment of phostrip, a/o, and bardenpho processes for biological phosphorus removal

    SciTech Connect

    1985-03-01

    This technology assessment addresses the process capabilities and limitations of three proprietary processes (PhoStrip, A/O, and Bardenpho) to biologically remove phosphorus from municipal wastewaters. The primary objective of this report is to provide guidance to individuals involved with reviewing new processes as part of the Innovative and Alternative Technology Program.

  16. Ionic Polymer-Coated Laccase with High Activity and Enhanced Stability: Application in the Decolourisation of Water Containing AO7

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaolin; Hua, Ming; Lv, Lu; Pan, Bingcai

    2015-02-01

    Eliminating dyes in environmental water purification remains a formidable challenge. Laccase is a unique, environmentally friendly and efficient biocatalyst that can degrade pollutants. However, the use of laccase for the degradation of pollutants is considerably limited by its susceptibility to environmental changes and its poor reusability. We fabricated a novel biocatalyst (LacPG) by coating polyethylenimine onto the native laccase (Lac) followed by crosslinking with glutaraldehyde. The stability of the resulting LacPG was highly enhanced against pH variations, thermal treatments and provided better long-term storage with a negligible loss in enzymatic activity. Compared to Lac, LacPG exhibited significantly higher decolourisation efficiency in the degradation of a representative azo dye, acid orange 7 (AO7), which resulted from the electrostatic attraction between the coating and AO7. LacPG was separated from the AO7 solution using an ultrafiltration unit. The increased size and modified surface chemistry of LacPG facilitated ultrafiltration and reduced membrane fouling. LacPG exhibited enhanced stability, high catalytic activity and favourable properties for membrane separation; therefore, LacPG could be continuously reused in an enzymatic membrane reactor with a high efficiency for decolourising water containing AO7. The developed strategy appears to be promising for enhancing the applicability of laccase in practical water treatment.

  17. Ionic polymer-coated laccase with high activity and enhanced stability: application in the decolourisation of water containing AO7.

    PubMed

    Zhang, Xiaolin; Hua, Ming; Lv, Lu; Pan, Bingcai

    2015-01-01

    Eliminating dyes in environmental water purification remains a formidable challenge. Laccase is a unique, environmentally friendly and efficient biocatalyst that can degrade pollutants. However, the use of laccase for the degradation of pollutants is considerably limited by its susceptibility to environmental changes and its poor reusability. We fabricated a novel biocatalyst (LacPG) by coating polyethylenimine onto the native laccase (Lac) followed by crosslinking with glutaraldehyde. The stability of the resulting LacPG was highly enhanced against pH variations, thermal treatments and provided better long-term storage with a negligible loss in enzymatic activity. Compared to Lac, LacPG exhibited significantly higher decolourisation efficiency in the degradation of a representative azo dye, acid orange 7 (AO7), which resulted from the electrostatic attraction between the coating and AO7. LacPG was separated from the AO7 solution using an ultrafiltration unit. The increased size and modified surface chemistry of LacPG facilitated ultrafiltration and reduced membrane fouling. LacPG exhibited enhanced stability, high catalytic activity and favourable properties for membrane separation; therefore, LacPG could be continuously reused in an enzymatic membrane reactor with a high efficiency for decolourising water containing AO7. The developed strategy appears to be promising for enhancing the applicability of laccase in practical water treatment. PMID:25652843

  18. Factors contributing to inconsistent condom use among heterosexual men in Curaçao.

    PubMed

    Stutterheim, Sarah E; Bertens, Madelief G B C; Mevissen, Fraukje E F; Schaalma, Herman P

    2013-01-01

    This study explored, from a public health perspective, factors that contribute to inconsistent condom use by men in Curaçao through semi-structured face-to-face interviews with 21 heterosexual men. The findings show that there is an important disconnect between what is considered culturally appropriate sexual behaviour for men and women and condom use, that diverging from prescribed notions of masculinity and femininity in order to use condoms consistently is difficult, and that condom use is particularly problematic in the context of concurrent partnerships and sexual economic exchanges. Participants further reported that Caribbean family structures, whereby mothers assume the role as primary caregiver and fathers contribute biologically but, to a much lesser extent socially, also have an impact on condom use. Additionally, consistent condom use was reported to be impeded by a cultural taboo on talking seriously about sex and sexual health. In their totality, findings provide important input from men for the development of sexual health promotion interventions that are cognizant of the cultural context in which inconsistent condom use occurs, and that are geared not only to the individual level but also to the interpersonal and structural levels. PMID:23350609

  19. Integration of SAXO, the VLT-SPHERE extreme AO : final performance

    NASA Astrophysics Data System (ADS)

    Fusco, Thierry; Sauvage, Jean-François; Petit, Cyril; Costille, Anne; Dohlen, Kjetil; Beuzit, Jean-Luc; Mouillet, David; Puget, Pascal; Gluck, Laurence; Rochat, Sylvain; Baruffolo, Andrea; Salasnich, Bernardo; Kasper, Markus; Suarez, Marcos; Soenke, Christian; Fedrigo, Enrico; Baudoz, Pierre; Sevin, Arnaud; Perret, Denis; Wildi, François

    2013-12-01

    The direct imaging of exoplanet is an up to date instrumental challenge, as well as a scientific exciting goal. Contrary to indirect methods, the study of exoplanet's own light witnesses for biomarkers presence in their atmosphere. Observing such a faint object close to its bright host star requires dedicated instrumental observation from the ground. SPHERE and GPI are two of these instruments, currently on final AIT phase, for a very first light during this year. Both instruments developed during the last 5 years are composed of extremely high performance AO system (XAO) able to compensate for the optical deformation caused by the turbulence of earth atmosphere. Moreover, the final performance of such a system is limited by the static light residuals present in the imaging focal plane, caused by uncorrected static optical aberrations. The direct imaging of exoplanet therefore also requires to perform self-calibration in order to attenuate these residual and enhance the coronagraphic extinction. This paper presents the final ongoing AIT results of the SPHERE instrument, and mainly focuses on XAO aspects. An exhaustive view of last SAXO performance in lab is shown. In particular, such improvement as the Optimised Modal Gain, optimized Kalman filtering of vibration, and Garbage collection are the key point to reach the final performance. The behavior of the instrument with realistic turbulence strength, wind speed, flux conditions are studied. The self-calibration module, based on phase diversity measurement of NCPA, demonstrates the ultimate performance of the instrument, in term of flux extinction and future scientific results.

  20. The Robo-AO KOI Survey: Laser Adaptive Optics Imaging of Every Kepler Exoplanet Candidate

    NASA Astrophysics Data System (ADS)

    Ziegler, Carl; Law, Nicholas M.; Baranec, Christoph; Morton, Tim; Riddle, Reed L.

    2016-01-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star (KOI) with laser adaptive optics imaging to hunt for blended nearby stars which may be physically associated companions. With the unparalleled efficiency provided by the first fully robotic adaptive optics system, we perform the critical search for nearby stars (0.15" to 4.0" separation with contrasts up to 6 magnitudes) that pollute the observed planetary transit signal, contributing to inaccurate planetary characteristics or astrophysical false positives. We present approximately 3300 high resolution observations of Kepler planetary hosts from 2012-2015, with ~500 observed nearby stars. We measure an overall nearby star probability rate of 16.2±0.8%. With this large dataset, we are uniquely able to explore broad correlations between multiple star systems and the properties of the planets which they host. We then use these clues for insight into the formation and evolution of these exotic systems. Several KOIs of particular interest will be discussed, including possible quadruple star systems hosting planets and updated properties for possible rocky planets orbiting in the habitable zone.

  1. Lycibarbarspermidines A-O, New Dicaffeoylspermidine Derivatives from Wolfberry, with Activities against Alzheimer's Disease and Oxidation.

    PubMed

    Zhou, Zheng-Qun; Fan, Hong-Xia; He, Rong-Rong; Xiao, Jia; Tsoi, Bun; Lan, Kang-Hua; Kurihara, Hiroshi; So, Kwok-Fai; Yao, Xin-Sheng; Gao, Hao

    2016-03-23

    Fifteen new dicaffeoylspermidine derivatives, lycibarbarspermidines A-O (1-15), were isolated from the fruit of Lycium barbarum (wolfberry). The structures were unambiguously determined by spectroscopic analyses and chemical methods. Dicaffeoylspermidine derivatives, a rare kind of plant secondary metabolites, are primarily distributed in the family of Solanaceae. Only six compounds were structurally identified, and all of them are acyclic aglycones. Compounds 1-15 are the first glycosidic products of dicaffeoylspermidine derivatives, and compounds 14-15 are the first cyclization products of dicaffeoylspermidine derivatives. Moreover, dicaffeoylspermidine derivatives were first isolated and identified from wolfberry. The short-term memory assay on a transgenic fly Alzheimer's disease (AD) model showed that 1-15 exhibited different levels of anti-AD activity. The oxygen radical absorbance capacity assay revealed that 1-15 all displayed antioxidant capacity. Both anti-AD and antioxidant functions are related to the effects of wolfberry. Therefore, dicaffeoylspermidine derivatives are considered beneficial constituents responsible for the antiaging, neuroprotective, anti-AD, and antioxidant effects of wolfberry. PMID:26953624

  2. LDEF (Postflight), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on Graphite-Polyimide and Graphite-Epoxy Mechanical Properties, Tray A01 The Graphite-Polyimide and Graphite-Epoxy Mechanical Properties experiment postflight photograph was taken in the Orbiter Processing Facility during the period when the LDEF was being transferred from the Orbiter cargo bay to the KSC Payload Transporter. The photograph shows considerably more detail than the flight photograph. The horizontal lines on the honeycomb panel that appear to be cracks from space exposure are instead fine lines of excess epoxy resin formed during the bagging and curing process. The harsh white color of the epoxy adhesive along the rivet lines is from the lighting conditions in the OPF. The brown discoloration on the paint dots and the stain on the aluminum mounting strips appear to have changed little from the flight photograph. The greater detail does show that a stain exists at most composite and mounting strip interfaces.

  3. Ruled and holographic experiment (AO 138-5). [long duration exposure facility

    NASA Technical Reports Server (NTRS)

    Bonnemason, Francis

    1992-01-01

    The AO 138-5 experiment has been designed, via the French Cooperative Payload (FRECOPA) experiment with the aim to study the optical behavior of different diffraction gratings submitted to space vacuum long exposure and solar radiation. Samples were rules and holographic gratings, masters or replica, and some additional control mirrors with various coatings. The experiment was located on the B3, trailing edge of the Long Duration Exposure Facility (LDEF) and has been protected against atomic oxygen flux. The experienced thermal cycling has been evaluated from -23 C to 66 C during the flight, 34,000 orbits. The analysis has been focused on the triple point characterization including light efficiency, wavefront flatness quality and stray light level. Tests were conducted on control mirrors and gratings loaded but not exposed to cosmic dust or solar irradiations. They did not show any significant variations. Solar exposure has damaged the coating reflectivity in the ultraviolet region, the degradation is higher with the gratings, in terms of efficiency. However, wavefront flatness quality and stray light level tests revealed no additional changes.

  4. An Analysis of Characteristics of Education Institutions Supported by AoA for Planning and Development of Instructional Programs in Aging.

    ERIC Educational Resources Information Center

    Craig, Bruce M.

    The institutional characteristics of postsecondary colleges and universities that were successful in all Administration on Aging (AoA) grant program competitions for career training or personnel in aging through the 1980-81 academic year are analyzed. The sustaining ability of first-time grantees in new AoA program competitions are compared to see…

  5. LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00020 LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The flight photograph of the Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp blocks of the experiment trays right flange and lower flange appear to be slightly discolored. The LDEF structure, top intercostal, has a dark brown discoloration adjacent to the black thermal panel. Aluminum particles from the degraded CVCHPE thermal blanket are also visible in this area. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminumized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of an atomic oxygen experiment (see S1001) by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners. The external CVCHPE materials have changed significantly. The Kapton on the thermal blanket aluminized Kapton cover appears to be completely eroded, except under Kel-F buttons used to secure the blanket, leaving only the very thin vapor deposited aluminum coating as a cover. Parts of the aluminum coating residue has moved to

  6. LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00354 LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The postflight photograph was taken in the SAEF II at KSC prior to removal of the experiment from the LDEF. The color of the white paint dots on the exper- iment tray clamp blocks appear to be unchanged. The LDEF structure, the intercostal on the right, has a dark brown discoloration adjacent to the black Earth end thermal panel. Aluminum pieces of the degraded CVCHPE thermal cover that were shown lodged in the vent area between the intercostal and the black thermal panel in the flight photograph are gone. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of Experiment S1001 by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners. The external surface of the CVCHPE has changed from that observed in the flight photograph. The thin vapor deposited aluminum coating, left after the Kapton eroded, is essentially gone with only fragments left near the edges of the thermal blanket. Pieces of a layer of Dacron mesh (bridle vail) material, used to separate the thermal cover from the thermal

  7. Fine Analysis of 121 Hermione, 45 Eugenia, and 90 Antiope Binary Asteroid Systems With AO Observations

    NASA Astrophysics Data System (ADS)

    Marchis, F.; Descamps, P.; Hestroffer, D.; Berthier, J.; de Pater, I.

    2004-11-01

    We report on a campaign of adaptive optics observations which focuses on 121 Hermione, 45 Eugenia, and 90 Antiope binary asteroids performed with ESO-VLT and Keck II telescopes in 2003-2004. A precessing Keplerian model was used to describe the motion of their companion. The orbital elements are determined accurately using data spanning more than 2 years. The satellite of 121 Hermione revolves at a= 775+/-14 km from the primary in P=2.5714+/-0.001 days with a low eccentricity (e=0.008+/-0.004) and retrograde orbit w.r.t. to the primary's equator (i=175+/-4 deg considering a pole solution (1.9,13.2) deg in ecliptic EQJ2000). The sense of revolution was unambiguously estimated from images separated by a few hours. Keck AO data taken in December 2003 revealed the bi-lobated shape of the primary. The nominal bulk density as derived from observed size of the primary and its 209 km IRAS diameter is 1.2+/-0.3 g/cm3 (Marchis et al., Icarus, 2004). Future observations with better angular resolution will allow us to see if 121 Hermione is a triple system. The orbit of Petit-Prince, moonlet of 45 Eugenia, was constrained using Feb. and Mar. 2004 AO data recorded at the VLT (a=1196+/-4 km, P= 4.7244+/-0.001 days, e=0, i=163+/-6 deg with a pole solution (133+/-3,-40+/-3 deg) in ecliptic B1950), leading to a bulk density of 1.17 g/cm3 considering its 215 km IRAS diameter. Both models predict successfully the positions reported for the discovery of Petit-Prince on Nov. 1998 and of S/2001 (121) 1 by Merline et al. (1999 and 2002). We will also present results on the same-size binary asteroid 90 Antiope, using the same analysis. Feb. and Mar. 2004 VLT-NACO data confirmed that both components are similar (with a Dm 2.4 and a diameter of 110+/-16 km). A preliminary analysis of Feb. and Mar. 2004 VLT data confirms that both components, separated by 170+/-1 km, with a revolution period P=16.5268 +- 0.0001h, are quasi-similar (with a Dm ˜ 2.4% and a diameter of 110+/-16 km) leading to

  8. Revolutionary visible and infrared sensor detectors for the most advanced astronomical AO systems

    NASA Astrophysics Data System (ADS)

    Feautrier, Philippe; Gach, Jean-Luc; Guieu, Sylvain; Downing, Mark; Jorden, Paul; Rothman, Johan; de Borniol, Eric D.; Balard, Philippe; Stadler, Eric; Guillaume, Christian; Boutolleau, David; Coussement, Jérome; Kolb, Johann; Hubin, Norbert; Derelle, Sophie; Robert, Clélia; Tanchon, Julien; Trollier, Thierry; Ravex, Alain; Zins, Gérard; Kern, Pierre; Moulin, Thibaut; Rochat, Sylvain; Delpoulbé, Alain; Lebouqun, Jean-Baptiste

    2014-07-01

    We report in this paper decisive advance on the detector development for the astronomical applications that require very fast operation. Since the CCD220 and OCAM2 major success, new detector developments started in Europe either for visible and IR wavelengths. Funded by ESO and the FP7 Opticon European network, the NGSD CMOS device is fully dedicated to Natural and Laser Guide Star AO for the E-ELT with strong ESO involvement. The NGSD will be a 880x840 pixels CMOS detector with a readout noise of 3 e (goal 1e) at 700 Hz frame rate and providing digital outputs. A camera development, based on this CMOS device and also funded by the Opticon European network, is ongoing. Another major AO wavefront sensing detector development concerns IR detectors based on Avalanche Photodiode (e- APD) arrays within the RAPID project. Developed by the SOFRADIR and CEA/LETI manufacturers, the latter offers a 320x255 8 outputs 30 microns IR array, sensitive from 0.4 to 3 microns, with less than 2 e readout noise at 1600 fps. A rectangular window can also be programmed to speed up even more the frame rate when the full frame readout is not required. The high QE response, in the range of 70%, is almost flat over this wavelength range. Advanced packaging with miniature cryostat using pulse tube cryocoolers was developed in the frame of this programme in order to allow use on this detector in any type of environment. The characterization results of this device are presented here. Readout noise as low as 1.7 e at 1600 fps has been measured with a 3 microns wavelength cut-off chip and a multiplication gain of 14 obtained with a limited photodiode polarization of 8V. This device also exhibits excellent linearity, lower than 1%. The pulse tube cooling allows smart and easy cooling down to 55 K. Vibrations investigations using centroiding and FFT measurements were performed proving that the miniature pulse tube does not induce measurable vibrations to the optical bench, allowing use of this

  9. Systemic lupus erythematosus on the Caribbean island of Curaçao: an epidemiological investigation.

    PubMed Central

    Nossent, J C

    1992-01-01

    To determine the incidence, prevalence, and outcome of systemic lupus erythematosus (SLE) in a well delineated black population in the Caribbean basin data were collected on the disease course of all patients with definite SLE seen during a 10 year period (1980-9) using three different sources of information (hospital records, private practice records, and death certificates). Ninety four patients were identified giving an average annual incidence rate of 4.6/100,000 (95% confidence interval (CI) 0.4 to 8.8), which showed little variation during the study period. Twenty five patients (27%) died during the study period, giving a point prevalence of 47/100,000 (CI 34.1 to 51.1) in 1990. In women aged 15-44 years the annual incidence (12/100,000; CI 5.3 to 18.9) was highest, whereas in women aged 44-65 years the 1990 point prevalence rate (one in 526; CI 469 to 625) was highest. Annual mortality was 1.7/100,000 (CI -0.8 to 4.2) with a female to male ratio of 5.3. Renal disease was the most common complication, occurring in 73 (78%) patients. Thus the transatlantic movement from an area with a (presumably) low prevalence of SLE (Central Africa) has been accompanied by an increase in the prevalence of SLE in the black population of Curaçao, indicating that environmental factors may prevail over genetic factors in the expression of this disease. PMID:1466595

  10. Climate Factors as Important Determinants of Dengue Incidence in Curaçao.

    PubMed

    Limper, M; Thai, K T D; Gerstenbluth, I; Osterhaus, A D M E; Duits, A J; van Gorp, E C M

    2016-03-01

    Macro- and microclimates may have variable impact on dengue incidence in different settings. We estimated the short-term impact and delayed effects of climate variables on dengue morbidity in Curaçao. Monthly dengue incidence data from 1999 to 2009 were included to estimate the short-term influences of climate variables by employing wavelet analysis, generalized additive models (GAM) and distributed lag nonlinear models (DLNM) on rainfall, temperature and relative humidity in relation to dengue incidence. Dengue incidence showed a significant irregular 4-year multi-annual cycle associated with climate variables. Based on GAM, temperature showed a U-shape, while humidity and rainfall exhibited a dome-shaped association, suggesting that deviation from mean temperature increases and deviation from mean humidity and rainfall decreases dengue incidence, respectively. Rainfall was associated with an immediate increase in dengue incidence of 4.1% (95% CI: 2.2-8.1%) after a 10-mm increase, with a maximum increase of 6.5% (95% CI: 3.2-10.0%) after 1.5 month lag. A 1 °C decrease of mean temperature was associated with a RR of 17.4% (95% CI: 11.2-27.0%); the effect was inversed for a 1°C increase of mean temperature (RR= 0.457, 95% CI: 0.278-0.752). Climate variables are important determinants of dengue incidence and provide insight into its short-term effects. An increase in mean temperature was associated with lower dengue incidence, whereas lower temperatures were associated with higher dengue incidence. PMID:26122819

  11. [Morphology of bone threads following implantation of 2 mm AO miniscrews in the midfacial area].

    PubMed

    Bähr, W

    1989-02-01

    How well an osteosynthesis screw holds depends on the amount of friction between the thread flank of the screw and the bone thread. Factors undermining the mechanical integrity of the bone thread, such as cracks, can lead to reduced friction and consequently less ability to hold. To investigate the micromorphology of the bone thread in the thin bone of the midface, 131 bony implant beds of 2-mm AO miniscrews and 10 drill holes which had been pretapped but received no screws were studied by incident light and scanning electron microscopy. The angle of insertion of the screws was varied to assess the effect this has on the implant bed surface. In 30 of the 131 implant beds the insertion axis of the screws corresponded to the axis of the threaded or unthreaded drill holes. Sixty-six of the screws had been inserted at an inclination of greater than or equal to 10 degrees to the axis of the pretapped hole. Twenty pretapped implant beds had an inclination between 0 degrees and 10 degrees to the drill hole. Finally, 15 bone threads formed by inclining the screws upon insertion into untapped drill holes were also studied. Both pretapped and untapped implant bed surfaces were damaged with cracks, as well as signs of squashing, crushing and shearing stress. The extent of the damage often varied in the different implant beds as well as at different locations in the same implant bed. The pretapped implant beds seemed to have a relatively smoother surface when the drill or threader and the screws had the same axis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2711189

  12. Screw fixation of medial malleolar fractures: a cadaveric biomechanical study challenging the current AO philosophy.

    PubMed

    Parker, L; Garlick, N; McCarthy, I; Grechenig, S; Grechenig, W; Smitham, P

    2013-12-01

    The AO Foundation advocates the use of partially threaded lag screws in the fixation of fractures of the medial malleolus. However, their threads often bypass the radiodense physeal scar of the distal tibia, possibly failing to obtain more secure purchase and better compression of the fracture. We therefore hypothesised that the partially threaded screws commonly used to fix a medial malleolar fracture often provide suboptimal compression as a result of bypassing the physeal scar, and proposed that better compression of the fracture may be achieved with shorter partially threaded screws or fully threaded screws whose threads engage the physeal scar. We analysed compression at the fracture site in human cadaver medial malleoli treated with either 30 mm or 45 mm long partially threaded screws or 45 mm fully threaded screws. The median compression at the fracture site achieved with 30 mm partially threaded screws (0.95 kg/cm(2) (interquartile range (IQR) 0.8 to 1.2) and 45 mm fully threaded screws (1.0 kg/cm(2) (IQR 0.7 to 2.8)) was significantly higher than that achieved with 45 mm partially threaded screws (0.6 kg/cm(2) (IQR 0.2 to 0.9)) (p = 0.04 and p < 0.001, respectively). The fully threaded screws and the 30mm partially threaded screws were seen to engage the physeal scar under an image intensifier in each case. The results support the use of 30 mm partially threaded or 45 mm fully threaded screws that engage the physeal scar rather than longer partially threaded screws that do not. A 45 mm fully threaded screw may in practice offer additional benefit over 30 mm partially threaded screws in increasing the thread count in the denser paraphyseal region. PMID:24293597

  13. Postoperative bedrest improves the alignment of thoracolumbar burst fractures treated with the AO spinal fixator

    PubMed Central

    Dang, Yen; Yen, David; Hopman, Wilma M.

    2009-01-01

    Background A loss of reduction due to inadequate support of the anterior column when using short-segment instrumentation to treat burst fracture and novel methods for support of the anterior column through a posterior approach to augment posterior instrumentation have been reported in the literature. We hypothesized that if anterior column support is an important adjunct to posterior short-segment instrumentation, then avoidance of axial load until sufficient anterior column healing occurs, allowing load-sharing with the implant, would improve spinal alignment at follow-up. Methods We conducted a retrospective cohort study in which consecutive patients who had instrumentation and fusion with the AO spinal fixator were immediately ambulated after surgery or had 4 weeks of bedrest. We measured kyphosis and wedge angles preoperatively, immediately postoperatively and at the time of final follow-up. We used radiologic measures to assess instrumentation and bone failure. Results We found significant differences in the mean loss of wedge and kyphosis angle correction between patients immediately ambulated and those who had 4 weeks of bedrest (0.71º v. − 4.73º for wedge and 1.81º v. − 6.55º for kyphosis, respectively). There was significant correlation between instrumentation and bone failure in both the immediate ambulation and bedrest groups. Conclusion Bedrest improves the maintenance of intraoperative sagittal alignment correction, which is in agreement with the theory that inadequate support of the anterior spinal column is the mechanism for loss of reduction when using short-segment instrumentation to treat burst fractures. Therefore, addressing the anterior column directly through anterior surgery or by employing novel techniques in posterior surgery is recommended if one of the goals of treatment is to maintain the sagittal correction achieved at the time of surgery. Trying to achieve this goal by addressing posterior implant design or bone quality alone

  14. High energy resolution observation of the Crab and AO535 plus 26 in the hard X-ray range

    NASA Astrophysics Data System (ADS)

    Hameury, J. M.; Boclet, D.; Durouchoux, P.; Cline, T.; Teegarden, B.; Tueller, J.; Paciesas, W.; Haymes, R.

    A number of uncertainties exist currently regarding the existence of gamma-ray lines in the Crab spectrum. An investigation was, therefore, conducted, and the Crab was observed for eight hours during a balloon flight from Palestine, TX, on September 26, 1980. It appeared that the binary source AO535 plus 26 contaminated the Crab data. It was, however, possible to separate the two sources. The obtained results are discussed and evaluated. It is found that the possibility of a line at 73 keV with the intensity reported by Ling et al. (1979) can be excluded for the obtained data. The 400 keV line cannot be ruled out. The results concerning AO535 plus 26 are very different from those previously obtained.

  15. High energy resolution observation of the Crab and AO535 plus 26 in the hard X-ray range

    NASA Technical Reports Server (NTRS)

    Hameury, J. M.; Boclet, D.; Durouchoux, P.; Cline, T.; Teegarden, B.; Tueller, J.; Paciesas, W.; Haymes, R.

    1982-01-01

    A number of uncertainties exist currently regarding the existence of gamma-ray lines in the Crab spectrum. An investigation was, therefore, conducted, and the Crab was observed for eight hours during a balloon flight from Palestine, TX, on September 26, 1980. It appeared that the binary source AO535 plus 26 contaminated the Crab data. It was, however, possible to separate the two sources. The obtained results are discussed and evaluated. It is found that the possibility of a line at 73 keV with the intensity reported by Ling et al. (1979) can be excluded for the obtained data. The 400 keV line cannot be ruled out. The results concerning AO535 plus 26 are very different from those previously obtained.

  16. First light curve analyses of binary systems AO Aqr, CW Aqr and ASAS 012206-4924.7

    NASA Astrophysics Data System (ADS)

    Ulaş, B.; Ulusoy, C.

    2015-11-01

    Using the data from the public database of the All Sky Automated Survey (ASAS) we performed the very first light curve analyses of the three eclipsing binary systems AO Aqr, CW Aqr and ASAS 012206-4924.7. The physical parameters of the systems were determined by the PHOEBE (Prša and Zwitter, 2005) software. From an analysis of the ASAS data it was concluded that AO Aqr was found to be a contact binary system while CW Aqr and ASAS 012206-4924.7 were found to be near-contact and detached binaries, respectively. Finally, the locations of the components, corresponding to the estimated physical parameters, in the HR diagram were also discussed.

  17. Relativistic blast-wave model for the rapid flux variations of AO 0235+164 and other compact radio sources

    NASA Technical Reports Server (NTRS)

    Marscher, A. P.

    1978-01-01

    A relativistic blast-wave version of a signal-screen model is developed which can adequately explain the details of the flux-density and structural variations of compact extragalactic radio sources. The relativistic motion implied by flux variations is analyzed with respect to the synchrotron spectrum of the BL Lac object AO 0235+164 observed during outbursts, and a signal-screen model for rapidly expanding shells produced by ultrarelativistic blast waves is examined. The approximate observed structure of the blast wave at three stages in its evolution is illustrated, each stage is described, and the model is applied to the flux density outburst in AO 0235+164 observed in late 1975. The results show that a relativistic blast-wave model can in general reproduce the main features of the observed flux variations in compact sources. Some problems with the proposed model are briefly discussed.

  18. Knee Osteochondritis Dissecans Treated by the AO Hook Fixation System: A Four Year Follow-Up of an Alternative Technique

    PubMed Central

    Pengas, Ioannis P; Assiotis, Angelos; Kokkinakis, Michail; Khan, Wasim S; Meyers, Paul; Arbuthnot, James; Mcnicholas, Michael J

    2014-01-01

    Surgical fixation is recommended for stable osteochondritis dissecans (OCD) lesions that have failed nonoperative management and for all unstable lesions. In this study we set out to describe and evaluate an alternative method of surgical fixation for such lesions. Five knees with unstable OCD lesions in four male adolescent patients with open physes were treated with the AO Hook Fixation System. The outcome was evaluated both clinically and with three separate outcome systems (IKDC 2000, KOOS, Lysholm) at one and a mean four year follow-up. We demonstrated excellent clinical results in all patients. At four years, all scoring systems demonstrated statistically significant improvement when compared to the preoperative status. Our study suggests that the AO Hook Fixation System is an alternative method of surgical intervention with comparable medium term results with other existing modes of fixation and the added biomechanical advantage of the absence of distracting forces during hardware removal. PMID:25067976

  19. Robo-AO Kepler Planetary Candidate Survey. II. Adaptive Optics Imaging of 969 Kepler Exoplanet Candidate Host Stars

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Ziegler, Carl; Law, Nicholas M.; Morton, Tim; Riddle, Reed; Atkinson, Dani; Schonhut, Jessica; Crepp, Justin

    2016-07-01

    We initiated the Robo-AO Kepler Planetary Candidate Survey in 2012 to observe each Kepler exoplanet candidate host star with high angular resolution, visible light, laser adaptive optics (AOs) imaging. Our goal is to find nearby stars lying in Kepler's photometric apertures that are responsible for the relatively high probability of false-positive exoplanet detections and that cause underestimates of the size of transit radii. Our comprehensive survey will also shed light on the effects of stellar multiplicity on exoplanet properties and will identify rare exoplanetary architectures. In this second part of our ongoing survey, we observed an additional 969 Kepler planet candidate hosts and we report blended stellar companions up to {{Δ }}m≈ 6 that contribute to Kepler's measured light curves. We found 203 companions within ˜4″ of 181 of the Kepler stars, of which 141 are new discoveries. We measure the nearby star probability for this sample of Kepler planet candidate host stars to be 10.6% ± 1.1% at angular separations up to 2.″5, significantly higher than the 7.4% ± 1.0% probability discovered in our initial sample of 715 stars; we find the probability increases to 17.6% ± 1.5% out to a separation of 4.″0. The median position of Kepler Objects of Interest (KOIs) observed in this survey are 1.°1 closer to the galactic plane, which may account for some of the nearby star probability enhancement. We additionally detail 50 Keck AO images of Robo-AO observed KOIs in order to confirm 37 companions detected at a <5σ significance level and to obtain additional infrared photometry on higher significance detected companions.

  20. AoRim15 is involved in conidial stress tolerance, conidiation and sclerotia formation in the filamentous fungus Aspergillus oryzae.

    PubMed

    Nakamura, Hidetoshi; Kikuma, Takashi; Jin, Feng Jie; Maruyama, Jun-Ichi; Kitamoto, Katsuhiko

    2016-04-01

    The serine-threonine kinase Rim15p is a master regulator of stress signaling and is required for stress tolerance and sexual sporulation in the yeast Saccharomyces cerevisiae. However, in filamentous fungi that reproduce asexually via conidiation, the physiological function of Rim15p homologs has not been extensively analyzed. Here, we functionally characterized the protein homolog of Rim15p in the filamentous fungus Aspergillus oryzae, by deleting and overexpressing the corresponding Aorim15 gene and examining the role of this protein in stress tolerance and development. Deletion of Aorim15 resulted in an increase in the sensitivity of conidia to oxidative and heat stresses, whereas conidia of the Aorim15 overexpressing strain were more resistant to these stresses. These results indicated that AoRim15 functions in stress tolerance, similar to S. cerevisiae Rim15p. Phenotypic analysis revealed that conidiation was markedly reduced by overexpression of Aorim15 in A. oryzae, and was completely abolished in the deletion strain. In addition, the formation of sclerotia, which is another type of developmental structure in filamentous fungi, was decreased by the deletion of Aorim15, whereas Aorim15 overexpression increased the number of sclerotia. These results indicated that AoRim15 is a positive regulator of sclerotia formation and that overexpression of AoRim15 shifts the developmental balance from conidiation towards sclerotia formation. Collectively, we demonstrated that AoRim15 is involved in the stress tolerance of conidia and differentially regulates between the two developmental fates of conidiation and sclerotia formation. PMID:26467693

  1. Open-loop control of SCExAO's MEMS deformable mirror using the Fast Iterative Algorithm: speckle control performances

    NASA Astrophysics Data System (ADS)

    Blain, Célia; Guyon, Olivier; Martinache, Frantz; Bradley, Colin; Clergeon, Christophe

    2012-07-01

    Micro-Electro-Mechanical Systems (MEMS) deformable mirrors (DMs) are widely utilized in astronomical Adaptive Optics (AO) instrumentation. High precision open-loop control of MEMS DMs has been achieved by developing a high accuracy DM model, the Fast Iterative Algorithm (FIA), a physics-based model allowing precise control of the DM shape. Accurate open-loop control is particularly critical for the wavefront control of High- Contrast Imaging (HCI) instruments to create a dark hole area free of most slow and quasi-static speckles which remain the limiting factor for direct detection and imaging of exoplanets. The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system is one of these high contrast imaging instruments and uses a 1024-actuator MEMS deformable mirror (DM) both in closed-loop and open-loop. The DM is used to modulate speckles in order to distinguish (i) speckles due to static and slow-varying residual aberrations from (ii) speckles due to genuine structures, such as exoplanets. The FIA has been fully integrated into the SCExAO wavefront control software and we report the FIA’s performance for the control of speckles in the focal plane.

  2. ShaneAO: an enhanced adaptive optics and IR imaging system for the Lick Observatory 3-meter telescope

    NASA Astrophysics Data System (ADS)

    Kupke, Renate; Gavel, Donald; Roskosi, Constance; Cabak, Gerald; Cowley, David; Dillon, Daren; Gates, Elinor L.; McGurk, Rosalie; Norton, Andrew; Peck, Michael; Ratliff, Christopher; Reinig, Marco

    2012-07-01

    The Lick Observatory 3-meter telescope has a history of serving as a testbed for innovative adaptive optics techniques. In 1996, it became one of the first astronomical observatories to employ laser guide star (LGS) adaptive optics as a facility instrument available to the astronomy community. Work on a second-generation LGS adaptive optics system, ShaneAO, is well underway, with plans to deploy on telescope in 2013. In this paper we discuss key design features and implementation plans for the ShaneAO adaptive optics system. Once again, the Shane 3-m will host a number of new techniques and technologies vital to the development of future adaptive optics systems on larger telescopes. Included is a woofer-tweeter based wavefront correction system incorporating a voice-coil actuated, low spatial and temporal bandwidth, high stroke deformable mirror in conjunction with a high order, high bandwidth MEMs deformable mirror. The existing dye laser, in operation since 1996, will be replaced with a fiber laser recently developed at Lawrence Livermore National Laboratories. The system will also incorporate a high-sensitivity, high bandwidth wavefront sensor camera. Enhanced IR performance will be achieved by replacing the existing PICNIC infrared array with an Hawaii 2RG. The updated ShaneAO system will provide opportunities to test predictive control algorithms for adaptive optics. Capabilities for astronomical spectroscopy, polarimetry, and visible-light adaptive optical astronomy will be supported.

  3. HIGH RESOLUTION H{alpha} IMAGES OF THE BINARY LOW-MASS PROPLYD LV 1 WITH THE MAGELLAN AO SYSTEM

    SciTech Connect

    Wu, Y.-L.; Close, L. M.; Males, J. R.; Follette, K.; Morzinski, K.; Kopon, D.; Rodigas, T. J.; Hinz, P.; Puglisi, A.; Esposito, S.; Pinna, E.; Riccardi, A.; Xompero, M.; Briguglio, R.

    2013-09-01

    We utilize the new Magellan adaptive optics system (MagAO) to image the binary proplyd LV 1 in the Orion Trapezium at H{alpha}. This is among the first AO results in visible wavelengths. The H{alpha} image clearly shows the ionization fronts, the interproplyd shell, and the cometary tails. Our astrometric measurements find no significant relative motion between components over {approx}18 yr, implying that LV 1 is a low-mass system. We also analyze Large Binocular Telescope AO observations, and find a point source which may be the embedded protostar's photosphere in the continuum. Converting the H magnitudes to mass, we show that the LV 1 binary may consist of one very-low-mass star with a likely brown dwarf secondary, or even plausibly a double brown dwarf. Finally, the magnetopause of the minor proplyd is estimated to have a radius of 110 AU, consistent with the location of the bow shock seen in H{alpha}.

  4. Novel UNC-44 AO13 ankyrin is required for axonal guidance in C. elegans, contains six highly repetitive STEP blocks separated by seven potential transmembrane domains, and is localized to neuronal processes and the periphery of neural cell bodies.

    PubMed

    Otsuka, Anthony J; Boontrakulpoontawee, Pratumtip; Rebeiz, Natalie; Domanus, Marc; Otsuka, Dawn; Velamparampil, Nena; Chan, Sabrina; Vande Wyngaerde, Marshall; Campagna, Sarah; Cox, Andrea

    2002-03-01

    Conventional ankyrins are cortical cytoskeletal proteins that form an ankyrin-spectrin meshwork underlying the plasma membrane. We report here the unusual structure of a novel ankyrin (AO13 ankyrin, 775,369 Da, 6994 aa, pI = 4.45) that is required for proper axonal guidance in Caenorhabditis elegans. AO13 ankyrin contains the ANK repeat and spectrin-binding domains found in other ankyrins, but differs from all others in that the acidic carboxyl region contains six blocks of serine/threonine/glutamic acid/proline rich (STEP) repeats separated by seven hydrophobic domains. The STEP repeat blocks are composed primarily of sequences related to ETTTTTTVTREHFEPED(E/D)X(n)VVESEEYSASGSPVPSE (E/K)DVE(H/R)VI, and the hydrophobic domains contain sequences related to PESGEESDGEGFGSKVLGFAKK[AGMVAGGVVAAPVALAAVGA]KAAYDALKKDDDEE, which includes a potential transmembrane domain (in brackets). Recombinant protein fragments of AO13 ankyrin were used to prepare polyclonal antisera against the spectrin-binding domain (AO271 Ab), the conventional ankyrin regulatory domain (AO280 Ab), the AO13 ankyrin STEP domain (AO346 Ab), the AO13 ankyrin STEP + hydrophobic domain (AO289 Ab), and against two carboxyl terminal domain fragments (AO263 Ab and AO327 Ab). Western blot analysis with these Ab probes demonstrated multiple protein isoforms. By immunofluorescence microscopy, the antispectrin-binding and regulatory domain (AO271 and AO280) antibodies recognized many cell types, including neurons, and stained the junctions between cells. The AO13 ankyrin-specific (AO289 and AO346) antibodies showed a neurally restricted pattern, staining nerve processes and the periphery of neural cell bodies. These results are consistent with a role for AO13 ankyrin in neural development. PMID:11891667

  5. Diferentes metodologias aplicadas ao ensino de astronomia no Ensino Médio

    NASA Astrophysics Data System (ADS)

    Albrecht, E.; Voelzke, M. R.

    2009-03-01

    O presente trabalho de intervenção foi realizado junto à Escola Estadual Colònia dos Pescadores na cidade de Caraguatatuba, com très turmas do terceiro ano do Ensino Médio, envolvendo 119 alunos com idades entre 16 e 19 anos. A fase inicial foi composta de um questionário de vinte questíes dissertativas e objetivas, aplicado pelo professor titular da sala, que era o mesmo nas très turmas, para diagnosticar nos educandos os conceitos prévios sobre Astronomia e, partindo destes realizar um trabalho de intervenção nas classes envolvidas utilizando, em cada uma, metodologias diferentes: (A) sob forma de seminários, elaborados e apresentados pelos educandos, no qual o educador faz apenas as intervençíes necessárias; (B) de forma tradicional, com auxílio de multimídias para desenvolvimento das aulas e a terceira (C) tradicional, fazendo uso exclusivo de lousa e giz. Ao final do trabalho os alunos responderam novamente o questionário inicial para diagnosticar dentre as très metodologias utilizadas qual apresentou melhores aplicaçíes, os resultados iniciais foram comparados com os finais. Quando questionados a respeito do significado de Astronomia observou-se inicialmente que os acertos na turma A foram de 100%, turma B: 64%, turma C: 84%, após a intervenção os acertos foram: 100%, 97% e 85% respectivamente, demonstrando que houve um avanço significativo na turma B, a turma A manteve seu índice e a turma C evoluiu, porém não tanto quanto a B. Quando interrogados sobre quantos planetas vocè acha que existem em nosso Sistema Solar? os acertos foram: turma A: 39%, turma B: 48% e turma C: 46%, após o desenvolvimento do trabalho os acertos foram 94%, 97% e 90% respectivamente. Dentro das respostas obtidas observa-se que a metodologia tradicional com o auxílio de multimeios, aplicada na turma B, demonstrou melhores resultados, sendo a mais significativa. Outra conclusão muito importante é que apesar de o tema Astronomia ser amplamente

  6. Future change of water vaiables from HadGEM2-AO simulation

    NASA Astrophysics Data System (ADS)

    Kim, Moon-Hyun; Kang, Hyun-Suk; Lee, Johan; Baek, Hee-Jeong; Cho, Chunho

    2013-04-01

    hydrology-atmosphere for water resource planning. Arora et al. (1999) and Oki and Sud (1998) developed a method for routing river flows through GCM grid cells. Accordingly, reliable forecasts are expected to help water managers and users with long lead time decisions, leading to greater water use efficiency and better risk management (Wang, 2012). SO, we analysed hydrological cycle and drought index from precipitation, evaporation, runoff, soil moisture, river outflow, and so on using atmosphere-ocean coupled model which called by HadGEM2-AO. Details and added information by this climate projection system about the future water cycle's change will be presented at the workshop. Acknowledgments: This research has been supported by project NIMR-2013-B-2 of the National Institute of Meteorological Research in Korea Meteorological Administration.

  7. LDEF (Postflight), AO044 : Holographic Data Storage Crystals for LDEF, Tray E05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The postflight photograph was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The Holographic Data Storage Crystals for LDEF Experiment (AO044) consist of four crystals of lithium niobate, three crystals contain recorded holograms and one crystal is an unrecorded control sample. The Holographic Data Storage experiment is an integral part of the Active Optical System Component Experiment (S0050) that contains 136 test specimen and is located in a six (6) inch deep LDEF peripheral experiment tray. The experiment tray is divided into six sections, each consisting of a 1/4 inch thick chromic anodized aluminum base plate and a 1/16th inch thick aluminum hat shaped structure for mounting the test specimen. The test specimen are typically placed in fiberglass-epoxy retainer strip assemblies prior to installation on the hat shaped mounting structure. Five of the six sections are covered by a 1/8 inch thick anodized aluminum sun screen with openings that allowed 56 percent transmission over the central region. Two subexperiments, The Optical Materials and UV Detectors Experiment (S0050-01) consist of 15 optical windows, filters and detectors and occupies one of the trays six sub-sections and The Optical Substrates and Coatings Experiment (S0050-02 ) that includes 12 substrates and coatings and a secondary experiment, ThePyroelectric Infrared Detectors Experiment with twenty detectors, are also mounted in the integrated tray. The experiment structure was assembled with non-magnetic stainless steel fasteners. The experiment hardware appears to be intact with no apparent damage. The excess blue color in the flight photograph is no longer present. The paint dots on the tray clamp blocks, initially white, are brown and tray flanges appear to have a light tan discoloration. The experiment sun screens and base plate also appear to have the same discoloration. The exposed experiment test specimen and their fiberglass-epoxy mountings appear to have

  8. LDEF (Postflight), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on Graphite-Polyimide and Graphite-Epoxy Mechanical Properties, Tray A07 The postflight photograph was taken in the Operations and Control (O&C) facility after the LDEF had been transferred from the KSC Payload Transporter to the LDEF Assembly and Transport System (LATS) and shows more detail than the flight photograph. The areas on the aluminum mounting strips where the coating has been scraped and/or abraided can be seen in greater detail under the better lighting conditions. The coating color remains essentially the same. The white paint dots on the tray clampblocks have changed little from the orginal color. PMR-15 Graphite-Polyimide Panel (precured) - The PMR-15 graphite-polyimide laminated panel (T40T30060-009) postflight photograph provides more detail than the flight photograph. The geometric pattern seen on the flight photograph is not visible, however, the horizontal lines, cracks and/or crazing, observed previously are better defined. A gray haze or dust appears to cover the gray/brown panel surface. The yellow colored identification numbers seem to be a little lighter than in the flight photograph but the white marking in the upper left corner do not appear to have changed. Scratch marks/abrasions on the lower left edge of panel were on prelaunch photographs. F-178/T300 Graphite-Polyimide Panel (cocured) - The 178/T300 graphite-polyimide panel (T40T30060-005) seems to have changed in color from the light gray in the flight photograph to a brownish gray. The yellow identification numbers seem lighter while the white marking in the upper left corner appear brighter. The fine horizontal lines, cracks and/or crazing, are still visible on the panel surface. F178/T300 Graphite-Polyimide Panel (precured) - The 178/T300 graphite-polyimide laminated panel (T40T30060-001) seems to have changed to a brownish gray from the light gray color seen in the flight photograph

  9. Modeling the effect of high altitude turbulence in wide-field correlating wavefront sensing and its impact on the performance of solar AO systems

    NASA Astrophysics Data System (ADS)

    Montilla, I.; Tallon, M.; Langlois, M.; Béchet, C.; Collados Vera, M.

    2014-08-01

    Solar Adaptive Optics (AO) shares many issues with night-time AO, but it also has its own particularities. The wavefront sensing is performed using correlations to efficiently work on the solar granulation as a reference. The field of view for that measurement usually is around 10". A sensor collecting such a wide field of view averages wavefront information from different sky directions, and the anisoplanatism thus has a peculiar impact on the performance of solar AO and MCAO systems. Since we are entering the era of large solar telescopes (European Solar Telescope, Advanced Technology Solar Telescope) understanding this issue is crucial to evaluate its impact on the performance of future AO systems. In this paper we model the correlating wide field sensor and the way it senses the high altitude turbulence. Thanks to this improved modelling, we present an analysis of the influence of this sensing on the performance of each AO configuration, conventional AO and MCAO. In addition to the analytical study, simulations similar to the case of the EST AO systems with FRiM-3D (the Fractal Iterative Method for Atmospheric tomography) are used in order to highlight the relative influence of design parameters. In particular, results show the performance evolution when increasing the telescope diameter. We analyse the effect of high altitude turbulence correlation showing that increasing the diameter of the telescope does not degrade the performance when correcting on the same spatial and temporal scales.

  10. The interobserver reliability of classification systems for radial head fractures: the Hotchkiss modification of the Mason classification and the AO classification systems

    PubMed Central

    Sheps, David M.; Kiefer, Krystina R.L.; Boorman, Richard S.; Donaghy, John; Lalani, Aleem; Walker, Richard; Hildebrand, Kevin A.

    2009-01-01

    Background Radial head fractures are common injuries, and there is little information on the reliability of classification systems for such injuries. The purpose of our study was to report the interobserver reliability of 2 commonly used classification systems: the Hotchkiss modification of the Mason classification and the AO classification systems. Methods We compiled the radiographs from a cohort series of 43 patients with radial head fractures, and 5 observers classified the radiographs according to both classification systems. Additionally, we collapsed the systems, with types II and III combined for the Hotchkiss classification and the final digit dropped for the AO classification. We calculated percent agreement, the κ statistic and the associated 95% confidence intervals (CIs). Results The mean percent agreement was 72.3% (95% CI 65.8%–78.9%) for the Hotchkiss classification and 37.7% (95% CI 30.5%–44.9%) for the AO classification. The κ statistic was 0.585 (0.541–0.661) for the Hotchkiss classification and 0.261 (0.240–0.350) for the AO classification. The mean percent agreement was 89.3% (86.6%–92.0%) for the consolidated Hotchkiss classification and 67.4% (54.6%–80.3%) for the consolidated AO classification. The κ statistic was 0.760 (0.691–0.805) for the consolidated Hotchkiss classification and 0.455 (0.372–0.521) for the consolidated AO classification. Conclusion The interobserver reliability for the Hotchkiss modification of the Mason classification was moderate, and that for the AO classification was fair according to the criteria of Landis and Koch. Collapsing the Hotchkiss classification improved the reliability to substantial, and collapsing the AO system improved reliability to the lower end of moderate. PMID:19680511

  11. AO/NAO Response to Climate Change. 2; Relative Importance of Low- and High-Latitude Temperature Changes

    NASA Technical Reports Server (NTRS)

    Rind, D.; Perlwitz, J.; Lonergan, P.; Lerner, J.

    2005-01-01

    Using a variety of GCM experiments with various versions of the GISS model, we investigate how different aspects of tropospheric climate changes affect the extratropical Arctic Oscillation (AO)/North Atlantic Oscillation (NAO) circulation indices. The results show that low altitude changes in the extratropical latitudinal temperature gradient can have a strong impact on eddy forcing of the extratropical zonal wind, in the sense that when this latitudinal temperature gradient increases, it helps force a more negative AO/NAO phase. In addition, local conditions at high latitudes can stabilize/destabilize the atmosphere, inducing negative/positive phase changes. To the extent that there is not a large temperature change in the tropical upper troposphere (either through reduced tropical sensitivity at the surface, or limited transport of this change to high levels), the changes in the low level temperature gradient can provide the dominate influence on the extratropical circulation, so that planetary wave meridional refraction and eddy angular momentum transport changes become uncorrelated with potential vorticity transports. In particular, the climate change that produces the most positive NAO phase change would have substantial warming in the tropical upper troposphere over the Pacific Ocean, with high latitude warming in the North Atlantic. An increase in positive phase of these circulation indices is still more likely than not, but it will depend on the degree of tropical and high latitude temperature response and the transport of low level warming into the upper troposphere. These are aspects that currently differ among the models used for predicting the effects of global warning, contributing to the lack of consensus of future changes in the AO/NAO.

  12. Laboratory results and status update for Pathfinder, the LINC-NIRVANA NGS ground-layer AO subsystem

    NASA Astrophysics Data System (ADS)

    Kopon, Derek; Conrad, Al; Bertram, Thomas; Herbst, Tom; Kürster, Martin; Berwein, Juergen; Ragazzoni, Roberto; Farinato, Jacopo; Viotto, Valentina; Bergomi, Maria; Rohloff, Ralf-Rainer; Baumeister, Harald; De Bonis, Fulvio; Hofferbert, Ralph; Brunelli, Alessandro; Arcidiacono, Carmelo; Pott, Jörg-Uwe; Bizenberger, Peter; Briegel, Florian; Meschke, Daniel; Mohr, Lars; Zhang, Xianyu; Kittmann, Frank

    2013-12-01

    The full LINC-NIRVANA instrument will be one of the most complex ground-based astronomical systems ever built. It will consist of multiple subsystems, including two multi-conjugate ground layer AO systems (MCAO) that drive the LBT adaptive secondaries, two mid-high layer AO systems with their own Xynetics 349 actuator DM's, a fringe tracker, and a beam combiner. In order to mitigate risk, we take a modular approach to instrument testing and commissioning by decoupling these subsystems individually. The first subsystem tested on-sky will be one of the ground-layer AO systems, part of a test-bed known as the Pathfinder. The Pathfinder consists of a 12-star pyramid WFS that drives one of the LBT's adaptive secondaries, a support structure known as "The Foot," and the infrared test camera (IRTC), which is used for acquisition and alignment. The 12 guide stars are acquired by moveable arms called "star enlargers," each of which contains its own optical path. The Pathfinder will be shipped from MPIA in Heidelberg, Germany to the LBT mountain lab on Mt. Graham, Arizona in February. The system will be unpacked, assembled in the LBT clean room, and internally optically aligned. We present the results of our system tests, including star enlarger alignment and system alignment. We also present our immediate plans for on-sky closed loop tests on the LBT scheduled for early Fall. Because plans for all ELTs call for ground layer correction, the Pathfinder provides valuable preliminary information not only for the full LINC-NIRVANA system, but also for future advanced MCAO systems.

  13. Multiplicity in the Jupiter Trojan Population: Low density of 617 Patroclus with Keck LGS AO and Perspective

    NASA Astrophysics Data System (ADS)

    Marchis, F.; Hestroffer, D.; Descamps, P.; Berthier, J.; Bouchez, A. H.; Campbell, R. D.; Chin, J. C. Y.; van Dam, M. A.; Hartman, S. K.; Johnasson, E. M.; Lafon, R. E.; Le Mignant, D.; de Pater, I.; Stomski, P. J.; Summers, D. M.; Wizinovich, P. L.; Wong, M. H.

    2005-12-01

    The system 617 Patroclus, the only binary Trojan known, was discovered in 2001 with the Hokupa'a Gemini-8m AO system. Because of their faintness (magnitude in visible mv>15.5), Trojan asteroids cannot be directly observed by most of the AO systems. In 2004, a Laser Guide Star (LGS) AO system was offered on the Keck-10m. We initiated an observing campaign, recording direct images of the 617 Patroclus double system in broadband filters with the NIRC2 near-infrared camera. The orbital parameters of the system were estimated using two methods and by including additional Gemini archive data (2001-2002), we obtained a consistent and accurate solution. The two components, separated by 680±20 km, revolve around their center of mass in 4.289±0.004 days in a roughly circular orbit (e ˜0.02-0.02). Using the thermal measurements by Fernandez et al. (2003), we derive (with a beaming parameter η =0.94) a radius of R1= 60.9 km and R2= 56.3 km (with an error of 1.6 km and an Av= 0.04). Even considering the uncertainty in the volume of the components, the density of 617 Patroclus (ρ = 0.8±0.15 g/cm3) is extremely low, if compared with the bulk-density of known binary C-type main-belt asteroids (ρ 1.2 g/cm3, see Marchis et al., ACM, 2005). Assuming that the system is made of the same material as Ganymede or Callisto (uncompressed density of 1.6 g/cm3), the bulk density yields to a macro-porosity of ˜50%. A more realistic smaller porosity (p ˜15 different composition, such as more water ice in the interior of 617 Patroclus, suggesting a formation in the distant outer regions of the solar system (Morbidelli et al., Nature, 2005). The origin of this tightly bound system will be also discussed (Marchis et al., Nature, in press, 2005). We will present a quality comparison of the LGS Keck system with various techniques and different AO systems, discussing the interest of this technique to broaden the search for multiple asteroids in all minor planet populations. This work was

  14. Optimal Sensor Arrangements in Angle of Arrival (AoA) and Range Based Localization with Linear Sensor Arrays

    PubMed Central

    Herath, Sanvidha C. K.; Pathirana, Pubudu N.

    2013-01-01

    This paper investigates the linear separation requirements for Angle-of-Arrival (AoA) and range sensors, in order to achieve the optimal performance in estimating the position of a target from multiple and typically noisy sensor measurements. We analyse the sensor-target geometry in terms of the Cramer–Rao inequality and the corresponding Fisher information matrix, in order to characterize localization performance with respect to the linear spatial distribution of sensors. Here in this paper, we consider both fixed and adjustable linear sensor arrays. PMID:24036585

  15. Getting lucky with adaptive optics: diffraction-limited resolution in the visible with current AO systems on large and small telescopes

    NASA Astrophysics Data System (ADS)

    Law, N. M.; Dekany, R. G.; Mackay, C. D.; Moore, A. M.; Britton, M. C.; Velur, V.

    2008-07-01

    We have recently demonstrated diffraction-limited resolution imaging in the visible on the 5m Palomar Hale telescope. The new LAMP instrument is a Lucky Imaging backend camera for the Palomar AO system. Typical resolutions of 35-40 mas with Strehls of 10-20% were achieved at 700nm, and at 500nm the FWHM resolution was as small as 42 milliarcseconds. In this paper we discuss the capabilities and design challenges of such a system used with current and near future AO systems on a variety of telescopes. In particular, we describe the designs of two planned Lucky Imaging + AO instruments: a facility instrument for the Palomar 200" AO system and its PALM3K upgrade, and a visible-light imager for the CAMERA low-cost LGS AO system planned for the Palomar 60" telescope. We introduce a Monte Carlo simulation setup that reproduces the observed PSF variability behind an adaptive optics system, and apply it to predict the performance of 888Cam and CAMERA. CAMERA is predicted to achieve diffraction-limited resolution at wavelengths as short as 350 nm. In addition to on-axis resolution improvements we discuss the results of frame selection with the aim of improving other image parameters such as isoplanatic patch sizes, showing that useful improvements in image quality can be made by Lucky+AO even with very temporally and spatially undersampled data.

  16. THE FIRST CIRCUMSTELLAR DISK IMAGED IN SILHOUETTE AT VISIBLE WAVELENGTHS WITH ADAPTIVE OPTICS: MagAO IMAGING OF ORION 218-354

    SciTech Connect

    Follette, Katherine B.; Close, Laird M.; Males, Jared R.; Wu, Ya-Lin; Morzinski, Katie M.; Hinz, Philip; Rodigas, Timothy J.; Kopon, Derek; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa

    2013-09-20

    We present high-resolution adaptive optics (AO) corrected images of the silhouette disk Orion 218-354 taken with Magellan AO (MagAO) and its visible light camera, VisAO, in simultaneous differential imaging mode at Hα. This is the first image of a circumstellar disk seen in silhouette with AO and is among the first visible light AO results in the literature. We derive the disk extent, geometry, intensity, and extinction profiles and find, in contrast with previous work, that the disk is likely optically thin at Hα. Our data provide an estimate of the column density in primitive, ISM-like grains as a function of radius in the disk. We estimate that only ∼10% of the total submillimeter derived disk mass lies in primitive, unprocessed grains. We use our data, Monte Carlo radiative transfer modeling, and previous results from the literature to make the first self-consistent multiwavelength model of Orion 218-354. We find that we are able to reproduce the 1-1000 μm spectral energy distribution with a ∼2-540 AU disk of the size, geometry, small versus large grain proportion, and radial mass profile indicated by our data. This inner radius is a factor of ∼15 larger than the sublimation radius of the disk, suggesting that it is likely cleared in the very interior.

  17. [Review of 40 years AO/ASIF. The development of the Veterinary Surgical Working Group for Osteosynthesis Questions(AO) in Veterinary Medicine (AOVET) and a systematic operative fracture treatment in animals].

    PubMed

    Kasa, G; Kasa, F; Kasa, A; Pohler, O

    2011-01-01

    With respect to the founding of the AOVET in 1969, the development of the systematic osteosynthesis in large and small animals is reviewed. With the introduction of the stable OS techniques corresponding to the principles and operative techniques developed by the organization of ASIF/AO (hum), the systematic operative fracture treatment in animals expanded remarkably. The application of the "absolutely" stable compression osteosynthesis was the basis for the successful fracture treatment in large animals. The systematic osteosynthesis in small animals was realized through the generation of a multitude of stabilization techniques for the different fracture types in the various anatomical areas and for special orthopaedic interventions. This was achieved through a specifically developed implant- instrument system and corresponding operation methods. This development was supported by instruction courses, published manuals and visiting fellowships. The extensive collaboration in research and development led to an increasing understanding of the diverse bone healing processes. The AOVET enjoyed a progressing integration into the AO/ASIF (hum) organization. PMID:22134662

  18. Evidence of a plasmid-encoded oxidative xylose-catabolic pathway in Arthrobacter nicotinovorans pAO1.

    PubMed

    Mihasan, Marius; Stefan, Marius; Hritcu, Lucian; Artenie, Vlad; Brandsch, Roderich

    2013-01-01

    Due to its high abundance, the D-xylose fraction of lignocellulose provides a promising resource for production of various chemicals. Examples of efficient utilization of d-xylose are nevertheless rare, mainly due to the lack of enzymes with suitable properties for biotechnological applications. The genus Arthrobacter, which occupies an ecological niche rich in lignocellulosic materials and containing species with high resistance and tolerance to environmental factors, is a very suitable candidate for finding D-xylose-degrading enzymes with new properties. In this work, the presence of the pAO1 megaplasmid in cells of Arthrobacter nicotinovorans was directly linked to the ability of this microorganism to ferment D-xylose and to sustain longer log growth. Three pAO1 genes (orf32, orf39, orf40) putatively involved in degradation of xylose were identified and cloned, and the corresponding proteins purified and characterized. ORF40 was shown to be a homotetrameric NADP(+)/NAD(+) sugar dehydrogenase with a strong preference for d-xylose; ORF39 is a monomeric aldehyde dehydrogenase with wide substrate specificity and ORF32 is a constitutive expressed transcription factor putatively involved in control of the entire catabolic pathway. Based on analogies with other pentose degradation pathways, a putative xylose oxidative pathway similar to the Weimberg pathway is postulated. PMID:23063486

  19. Prolonged plume volcanism in the Caribbean Large Igneous Province: New insights from Curaçao and Haiti

    NASA Astrophysics Data System (ADS)

    Loewen, Matthew W.; Duncan, Robert A.; Kent, Adam J. R.; Krawl, Kyle

    2013-10-01

    We present 36 new 40Ar-39Ar incremental heating age determinations from the Caribbean Large Igneous Province (CLIP) providing evidence for extended periods of volcanic activity and suggest a new tectonomagmatic model for the province's timing and construction. These new 40Ar-39Ar ages for the Curaçao Lava Formation (CLF) and Haiti's Dumisseau Formation show evidence for active CLIP volcanism from 94 to 63 Ma. No clear changes in geochemical character are evident over this period. The CLF has trace element signatures (e.g., Zr/Nb = 10-20) and flat rare earth element (REE) trends consistent with plume volcanism. The Dumisseau Formation also has plume-like geochemistry and steeper REE trends similar to ocean island basalts. Volcanism in the Dumisseau Formation appears to have largely ceased by 83 Ma while at Curaçao it continued until 63 Ma. A rapidly surfacing and melting plume head alone does not fit this age distribution. Instead, we propose that the residual Galapagos plume head, following initial ocean plateau construction, was advected eastward by asthenospheric flow induced by subducting oceanic lithosphere. Slab rollback at the Lesser Antilles and Central America subduction zones created an extensional regime within the Caribbean plate. Mixing of plume with upwelling asthenospheric mantle provided a source for intermittent melting and eruption through the original plateau over a ˜30 Ma period.

  20. The Triaxial Ellipsoid Diameters and Rotational Pole of Asteroid (9) Metis from AO at Gemini and Keck

    NASA Astrophysics Data System (ADS)

    Drummond, Jack D.; Merline, W. J.; Conrad, A.; Dumas, C.; Tamblyn, P.; Christou, J.; Carry, B.; Chapman, C.

    2012-10-01

    From Adaptive Optics (AO) images of (9) Metis at 14 epochs over 2008 December 8 and 9 at Gemini North, triaxial ellipsoid diameters of 218x175x112 km are derived with fitting uncertainties of 3x3x47 km. However, by including just two more AO images from Keck-II in June and August of 2003 in a global fit, the fitting uncertainty of the small axis drops by more than a third because of the lower sub-Earth latitude afforded in 2003 (-28°) compared to 2008 (+47°), and the triaxial ellipsoid diameters become 218x175x129 km with fitting uncertainties of 3x3x14 km. We have estimated the systematic uncertainty of our method to be 4.1, 2.7, and 3.8%, respectively, for the three diameters. These values were recently derived (Drummond et al., in prep) from a comparison of KOALA (Carry et al, Planetary and Space Science 66, 200-212) and our triaxial ellipsoid analysis of four asteroids. Quadratically adding this systematic error with the fitting error, the total uncertainty for Metis becomes 9x5x15 km. Concurrently, we find an EQJ2000 rotational pole at [RA; Dec]=[185° +19°] or in ecliptic coordinates, [λ ; β ]=[176° +20°] (ECJ2000).

  1. Use of a single 2.0-mm locking AO reconstruction titanium plate in linear, non-comminuted, mandible fractures

    PubMed Central

    Parmar, Babu S.; Makwana, Kalpesh G.; Patel, Aditi M.; Tandel, Ramanuj C.; Shah, Jay

    2014-01-01

    Purpose: The aim of the following study is to prospectively evaluate the use of a single Arbeitsgemeinschaft für Osteosynthesefragen (AO) 2.0-mm locking reconstruction plate for linear non-comminuted mandibular fractures without the use of a second plate. Materials and Methods: This study consisted of a sample of 10 patients who reported to the department with fractures of the mandible and were treated over a period of 24 months from November 2010 to November 2012. Out of these, there were 8 male patients and 2 female patients. There were four cases of isolated parasymphysis fractures, 1 of the case had a parasymphysis fracture associated with subcondylar fracture, 4 had a body fracture and 2 had a symphysis fracture. Results: All patients had satisfactory fracture reduction and a successful treatment outcome without major complications. Only one patient (10%) developed minor complications. Conclusion: The study has demonstrated that treating linear non-comminuted mandibular fractures with a single AO 2.0-mm locking reconstruction plate provides excellent stability at the fracture site which in turn leads to sound bone healing and early functional rehabilitation. PMID:24987599

  2. AO/NAO response to climate change: 2. Relative importance of low- and high-latitude temperature changes

    NASA Astrophysics Data System (ADS)

    Rind, D.; Perlwitz, J.; Lonergan, P.; Lerner, J.

    2005-06-01

    We address the issue of why different models may be getting different responses of the AO/NAO in climate change experiments. The results from part 1 (Rind et al., 2005) suggest that for substantive climate changes, the differences are likely to be found in the patterns of tropospheric climate change, rather than from the stratosphere. We assess the various tropospheric forcings through a variety of experiments. We first use extreme paleoclimate experiments (Ice Age, Paleocene) which feature large variations in the low level latitudinal temperature gradient; the results show that under these circumstances, changes in the eddy transport of sensible heat, and in situ high latitude forcing, dominate the AO response. We next test the effect of more modest SST temperature gradient changes in the current climate, and find a similar result with a model configuration that does not easily transport the low level temperature changes into the upper troposphere. We then reanalyze the results from different 2 × CO2 experiments with the GISS model and find that they can be understood by assessing: (1) the magnitude of tropical SST warming; (2) the translations of that warming into the upper troposphere; (3) the change in the extratropical low altitude temperature gradient; and (4) the change in the high latitude SST/sea ice response. We suggest that these features might explain the varying results among modeling groups, and that forecasts will not converge until these features do.

  3. Tetrahedral tilting and ferroelectricity in Bi2AO5 (A=Si, Ge) from first principles calculations

    NASA Astrophysics Data System (ADS)

    Park, Janghee; Kim, Bog G.; Mori, Shigeo; Oguchi, Tamio

    2016-03-01

    The properties of a tetrahedron containing Bi2AO5 (A=Si, Ge) are examined using Ab initio calculations and symmetry mode analysis. Stabilization of the polar phase is observed in both compounds with a monoclinic Cc phase. In the monoclinic ground state, the tilting angle (ϕ1) of tetrahedron is 7.21° and 21.94° for the Si and Ge compound, respectively. The relationship between a primary order parameter and the tetrahedral tilting is identified and an analytical formula between them is proposed by analyzing the structure. The detailed layer-by-layer polarization calculations shows that the main polarization component originates from the tetrahedron tilting of the AO4 unit, and the analytical relationship between the primary order parameter and spontaneous polarization is also calculated. This B3LYP hybrid functional calculation provides a band gap of 4.44 eV and 4.18 eV for Bi2SiO5 and Bi2GeO5, respectively. The main difference between the two compounds is also analyzed based on the electronic structure and electron localization function analysis.

  4. Simultaneous removal of nutrients from milking parlor wastewater using an AO2 sequencing batch reactor (SBR) system.

    PubMed

    Wu, Xiao; Zhu, Jun

    2015-01-01

    The feasibility of using a lab-scale, anaerobic-aerobic-anoxic-aerobic sequencing batch reactor ((AO)2 SBR) to simultaneously remove biological organics, nitrogen and phosphorus from dairy milking parlor wastewater was investigated in this study. Three hydraulic retention times (HRT = 2.1, 2.7, and 3.5 days) and three mixing-to-process time ratios (TM/TP = 0.43, 0.57, and 0.68) were evaluated as two controlling factors using a 3 × 3 experimental design to determine the optimal combination. Results showed that the HRT of 2.7 days with TM/TP = 0.57 was the best to achieve simultaneous nutrients removal for the influent with initial soluble chemical oxygen demand (SCOD) of about 2000 mg L(-1) (only 0.55 mg L(-1) NH4-N, < 0.1 mg L(-1) nitrate, and 0.14 mg L(-1) soluble phosphorus in the effluent). Good correlations between pH and ORP, and ORP and DO, were also obtained with correlation coefficients all higher than or equal to 0.975. These relationships could be used to develop real-time control strategies to optimize the duration of each operating phase in the (AO)2 SBR system to save energy and enhance treatment efficiency. PMID:25723066

  5. English vowel production by native Mandarin speakers: Influences of AoA, LoR, education, perception, and orthography

    NASA Astrophysics Data System (ADS)

    Bell-Berti, Fredericka; Yu, Yan Helen

    2005-09-01

    This study investigates relations among several factors that are expected to influence vowel production in second language learning, including AoA, LoR, L2 and general education, L2 perception, and orthography. Vowel production will be examined through duration and formant frequency measurements and listener identification. The results will be analyzed in relation to educational background and language use. Among the educational factors examined are general education level, English education (in their native land and/or New York City), and sound-annotating system experiences in Mandarin (Pinyin or Zhuyin). The language-use factors include AoA, LoR, language spoken at work and at home, and perception of English vowels. The hypotheses addressed include: (1) educational background, language use, and sound-annotating system experiences in Mandarin all influence L2 English speakers perception and production of English vowels; (2) the more accurately an L2 listener discriminates a vowel contrast, the more distinctly he/she produces that contrast.

  6. A new polymer-based laccase for decolorization of AO7: long-term storage and mediator reuse.

    PubMed

    Zhang, Xiaolin; Pan, Bingcai; Wu, Bing; Zhang, Weiming; Lv, Lu

    2014-07-01

    To address the bottlenecks of laccase-based catalysis, i.e., poor long-term stability and potential secondary pollution caused by synthetic mediator, we fabricated a new biocatalyst (N-PS-Lac) through adsorption of laccase onto polystyrene anion exchangers (N-PS) binding quaternary ammonium groups. After 2-year storage, the residual activity of N-PS-Lac remained as high as 101.7%, while that for native laccase was only 14.6%. Also, N-PS-Lac exhibited improved durability against pH variation and thermal treatment at 60°C. Gaussian curve fitting of FT-IR spectra indicated that laccase conformation of N-PS-Lac was rigidified, possibly because of the host geometric restriction and the host-laccase electrostatic attraction. A two-step method, i.e., adsorption of an azo dye AO7 by N-PS and then ectopic degradation by the immobilized laccase, was proposed to reuse the mediator HOBT for seven cyclic runs, where N-PS-Lac kept the constant decolorization efficiency. AO7 solution was detoxified completely after decolorization by the two-step method. PMID:24862000

  7. Implications of 187Os isotopic heterogeneities in a mantle plume: evidence from Gorgona Island and Curaçao

    NASA Astrophysics Data System (ADS)

    Walker, Richard J.; Storey, Michael; Kerr, Andrew C.; Tarney, John; Arndt, Nicholas T.

    1999-03-01

    Recent work has suggested that the mafic-ultramafic volcanism in evidence throughout portions of the Caribbean, Central America, and northern South America, including the islands of Gorgona and Curaçao, was generated as part of a middle-Cretaceous, large igneous province. New Re-Os isochron results for tholeiitic basalts from Gorgona and Curaçao indicate crystallization ages of 89.2 ± 5.2 and 85.6 ± 8.1 Ma, respectively, consistent with reported Ar ages. The Gorgona ultramafic suite shows a large range in initial Os isotopic composition, with γ Os values ranging from -0.5 to +12.4. This large range reflects isotopic heterogeneities in the mantle source similar to those observed for modern ocean island basalts. In contrast to ocean island basalts, however, Os isotopic compositions do not correlate with variations in Nd, Sr, or Pb isotopic compositions, which are within the range of depleted mid-ocean ridge basalts. The processes that produced these rocks evidently resulted in the decoupling of Os isotopes from the Nd, Sr, and Pb isotopic systems. Picrites from Curaçao have very uniform, chondritic initial Os isotopic compositions, with initial γ Os values ranging only from -0.4 to ±1.4. Basalts from Curaçao, however, define an isochron with a 187Os-enriched initial isotopic composition (γ Os = +9.5). In contrast to the 187Os-enriched ultramafic rocks from Gorgona, the enrichment in these basalts could have resulted from lithospheric contamination. If the Gorgona and Curaçao rocks were derived from the same plume, Os results, combined with Sr, Nd, and Pb data indicate a heterogeneous plume, with multiple compositionally and isotopically distinct domains. The Os isotopic results require derivation of Os from a minimum of two distinct reservoirs, one with a composition very similar to the chondritic average and one with long-term enriched Re/Os. Oceanic crustal recycling has been invoked to explain most of the 187Os enrichments that have been observed in

  8. Not your "typical island woman": anorexia nervosa is reported only in subcultures in Curaçao.

    PubMed

    Katzman, Melanie A; Hermans, Karin M E; Van Hoeken, Daphne; Hoek, Hans W

    2004-12-01

    Anorexia nervosa (AN), once thought to be a problem of wealthier, Western countries has now been documented in survey studies and case reports across geographic and economic groups; however, few epidemiological studies including interview have been done on these populations. We report on a comprehensive study on Curaçao, a Caribbean island in economic transition, where the majority of the population is of predominantly black African origin. As part of an epidemiological study on the island of Curaçao indigenous cases of AN were identified. Participants were interviewed and asked to complete standardized measures of eating behaviors and cultural attitudes. In addition, matched controls completed the same measures and were seen in a focus group to assess their knowledge of eating disorders and perceived current and future challenges to young Curaçao women. Six of the nine indigenous cases of AN were successfully traced; all were of mixed race. No cases of anorexia were found among the majority black population. The women with AN were from the high-education and high-income sectors of the society and the majority had spent time overseas. The women with a history of anorexia reported higher levels of perfectionism and anxiety than the matched controls. All of the women reported challenges to maintaining an active professional and personal life and viewed themselves as different from the norm. Women who presented with AN evidenced vulnerability to a triple threat to identity formation: (1) they were of mixed race, aspiring to fit into the mobile elite (and mostly white) subgroup while distancing themselves from the black majority; (2) they had the means for education and travel that left them caught between modern and traditional constructs of femininity; and (3) they had lived overseas, and therefore struggled upon reentry with the frustrations of what was possible within the island culture. The race, class and overseas exposures of the women with anorexia were

  9. ROSAT guest investigator program (AO-1). On a search for coronal x ray emissions from white dwarfs

    NASA Technical Reports Server (NTRS)

    Musielak, Z. E.

    1992-01-01

    We have suggested that cool magnetic white dwarfs may be sources of X-ray coronal emission and proposed several prominent candidates for this emission. One of these candidates (EG 250) was approved for the C-category observation by the National and International Committee and was observed by ROSAT on April 17, 1991. Unfortunately, the granted exposure time (1071 s) was much shorter than that which was required by theoretical predictions to observe coronal X-ray emission from this object. The tape containing the data was send to us in November 1991. Since then we have analyzed the data visiting the ROSAT Science Center at NASA Goddard Space Flight Center. The analysis of the data taken during this short observation show, as expected, no X-rays. It is our hope that EG 250 will be observed again during the AO-2 phase of pointed observations, as 10,000 s of observing time was granted to V. Trimble for the C-category observation of this star. We have a close contact with Dr. Trimble regarding this matter. Because our all targets (GD 90, KUV 2316-123 and GD 356) proposed for the observation during the AO-2 phase of pointed observations have been approved by the National and International Committee, we have installed the required software at NASA/MSFC to be able to carry out the data analysis in Huntsville. Two of our targets have already been observed (KUV 2316-123 was observed on Dec. 3, 1991 with 10,000 s of the exposure time, and GD 356 was observed on Jan 4, 1992 with 5,000 s of the exposure time). We just received the data and will begin the analysis soon. The results of our analysis will be reported to the scientific community by publishing papers in the Astrophysical Journal Letters. Our intention is to submit a paper when the analysis of the data taken during AO2 is completed. The data taken during the observation of EG 250 will be a part of this paper.

  10. Search of Binary Jupiter-Trojan Asteroids with Laser Guide Star AO systems: a moon around 624 Hektor

    NASA Astrophysics Data System (ADS)

    Marchis, Franck; Berthier, J.; Wong, M. H.; Descamps, P.; Hestroffer, D.; Colas, F.; de Pater, I.; Vachier, F.

    2006-09-01

    In 2006, we initiated a search for multiple asteroids in Jupiter Trojan L4 population with Laser Guide Star Adaptive Optics (LGS AO) technology on 8-10m class telescopes. To maximize the chance of detecting companion, we prioritized Trojan asteroids that could be member of collisional families in our search (see the PeTrA project and Beaugé and Roig (A&A, 2001)). Our first night was performed on July 17 2006 UT with the Keck LGS AO system. Twenty targets up to the 18th magnitude in R band were observed mostly in Kp broadband filter with an angular resolution 0.06 arcsec. Images of 624 Hektor, our brightest target (predicted V=14.4) revealed the presence of a moonlet companion (Marchis et al., IAU, 2006, provisional designation S/2006(624)1) located at 0.36” ( 1150 km) from the primary with a peak SNR 25. The resolved primary has a bilobated shape, but it is unclear if the primary is a contact or separated binary. It can be approximated as an ellipse with major and minor axes 2a = 350 km and 2b = 210 km (108 and 65 milli-arcseconds). The pole solution λ=329°, β=-25° in ecliptic B1950 (Magnusson 1989, and updated table) is in agreement with the observations. Based on the integrated brightness ratio between the moonlet and the primary of about 6.5, the diameter of S/2006(624)1 is estimated to be about 15 km. Additional observations will be recorded using the Keck and Gemini LGS AO system in Aug-Sept. 2006 aiming to estimate the orbit of the moonlet. The conditions of observations seem optimal since the system will be seen pole-on during this period. 624 Hektor is the first binary asteroid found in the L4 point and the first Trojan possessing a moonlet companion. The result of this campaign of observations, including Aug-Sept. observations, will be discussed.

  11. A novel mammalian expression system derived from components coordinating nicotine degradation in arthrobacter nicotinovorans pAO1.

    PubMed

    Malphettes, Laetitia; Weber, Cornelia C; El-Baba, Marie Daoud; Schoenmakers, Ronald G; Aubel, Dominique; Weber, Wilfried; Fussenegger, Martin

    2005-01-01

    We describe the design and detailed characterization of 6-hydroxy-nicotine (6HNic)-adjustable transgene expression (NICE) systems engineered for lentiviral transduction and in vivo modulation of angiogenic responses. Arthrobacter nicotinovorans pAO1 encodes a unique catabolic machinery on its plasmid pAO1, which enables this Gram-positive soil bacterium to use the tobacco alkaloid nicotine as the exclusive carbon source. The 6HNic-responsive repressor-operator (HdnoR-O(NIC)) interaction, controlling 6HNic oxidase production in A.nicotinovorans pAO1, was engineered for generic 6HNic-adjustable transgene expression in mammalian cells. HdnoR fused to different transactivation domains retained its O(NIC)-binding capacity in mammalian cells and reversibly adjusted transgene transcription from chimeric O(NIC)-containing promoters (P(NIC); O(NIC) fused to a minimal eukaryotic promoter [P(min)]) in a 6HNic-responsive manner. The combination of transactivators containing various transactivation domains with promoters differing in the number of operator modules as well as in their relative inter-O(NIC) and/or O(NIC)-P(min) spacing revealed steric constraints influencing overall NICE regulation performance in mammalian cells. Mice implanted with microencapsulated cells engineered for NICE-controlled expression of the human glycoprotein secreted placental alkaline phosphatase (SEAP) showed high SEAP serum levels in the absence of regulating 6HNic. 6HNic was unable to modulate SEAP expression, suggesting that this nicotine derivative exhibits control-incompatible pharmacokinetics in mice. However, chicken embryos transduced with HIV-1-derived self-inactivating lentiviral particles transgenic for NICE-adjustable expression of the human vascular endothelial growth factor 121 (VEGF121) showed graded 6HNic response following administration of different 6HNic concentrations. Owing to the clinically inert and highly water-soluble compound 6HNic, NICE-adjustable transgene control

  12. ROSAT guest investigator program (AO-1). On a search for coronal X ray emissions from white dwarfs

    NASA Astrophysics Data System (ADS)

    Musielak, Z. E.

    1992-03-01

    We have suggested that cool magnetic white dwarfs may be sources of X-ray coronal emission and proposed several prominent candidates for this emission. One of these candidates (EG 250) was approved for the C-category observation by the National and International Committee and was observed by ROSAT on April 17, 1991. Unfortunately, the granted exposure time (1071 s) was much shorter than that which was required by theoretical predictions to observe coronal X-ray emission from this object. The tape containing the data was send to us in November 1991. Since then we have analyzed the data visiting the ROSAT Science Center at NASA Goddard Space Flight Center. The analysis of the data taken during this short observation show, as expected, no X-rays. It is our hope that EG 250 will be observed again during the AO-2 phase of pointed observations, as 10,000 s of observing time was granted to V. Trimble for the C-category observation of this star. We have a close contact with Dr. Trimble regarding this matter. Because our all targets (GD 90, KUV 2316-123 and GD 356) proposed for the observation during the AO-2 phase of pointed observations have been approved by the National and International Committee, we have installed the required software at NASA/MSFC to be able to carry out the data analysis in Huntsville. Two of our targets have already been observed (KUV 2316-123 was observed on Dec. 3, 1991 with 10,000 s of the exposure time, and GD 356 was observed on Jan 4, 1992 with 5,000 s of the exposure time). We just received the data and will begin the analysis soon. The results of our analysis will be reported to the scientific community by publishing papers in the Astrophysical Journal Letters. Our intention is to submit a paper when the analysis of the data taken during AO2 is completed. The data taken during the observation of EG 250 will be a part of this paper.

  13. A SURVEY OF THE HIGH ORDER MULTIPLICITY OF NEARBY SOLAR-TYPE BINARY STARS WITH Robo-AO

    SciTech Connect

    Riddle, Reed L.; Bui, Khanh; Dekany, Richard G.; Kulkarni, Shrinivas; Tendulkar, Shriharsh P.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Roberts, Lewis C. Jr.; Baranec, Christoph; Law, Nicholas M.; Burse, Mahesh P.; Das, H. K.; Punnadi, Sujit; Ramaprakash, A. N.

    2015-01-20

    We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive optics instrument, we collected high angular resolution images with deep and well-defined detection limits in the Sloan Digital Sky Survey i' band. A total of 695 components belonging to 595 systems were observed. We prioritized observations of faint secondary components with separations over 10'' to quantify the still poorly constrained frequency of their subsystems. Of the 214 secondaries observed, 39 contain such subsystems; 19 of those were discovered with Robo-AO. The selection-corrected frequency of secondary subsystems with periods from 10{sup 3.5} to 10{sup 5} days is 0.12 ± 0.03, the same as the frequency of such companions to the primary. Half of the secondary pairs belong to quadruple systems where the primary is also a close pair, showing that the presence of subsystems in both components of the outer binary is correlated. The relatively large abundance of 2+2 quadruple systems is a new finding, and will require more exploration of the formation mechanism of multiple star systems. We also targeted close binaries with periods less than 100 yr, searching for their distant tertiary components, and discovered 17 certain and 2 potential new triples. In a subsample of 241 close binaries, 71 have additional outer companions. The overall frequency of tertiary components is not enhanced, compared to all (non-binary) targets, but in the range of outer periods from 10{sup 6} to 10{sup 7.5} days (separations on the order of 500 AU), the frequency of tertiary components is 0.16 ± 0.03, exceeding the frequency of similar systems among all targets (0.09) by almost a factor of two. Measurements of binary stars with Robo-AO allowed us to compute first orbits for 9 pairs and to improve orbits of another 11 pairs.

  14. Final performance and lesson-learned of SAXO, the VLT-SPHERE extreme AO: from early design to on-sky results

    NASA Astrophysics Data System (ADS)

    Fusco, T.; Sauvage, J.-F.; Petit, C.; Costille, A.; Dohlen, K.; Mouillet, D.; Beuzit, J.-L.; Kasper, M.; Suarez, M.; Soenke, C.; Fedrigo, E.; Downing, M.; Baudoz, P.; Sevin, A.; Perret, D.; Barrufolo, A.; Salasnich, B.; Puget, P.; Feautrier, F.; Rochat, S.; Moulin, T.; Deboulbé, A.; Hugot, E.; Vigan, A.; Mawet, D.; Girard, J.; Hubin, N.

    2014-08-01

    The extreme AO system, SAXO (SPHERE AO for eXoplanet Observation), is the heart of the SPHERE system, feeding the scientific instruments with flat wave front corrected from all the atmospheric turbulence and internal defects. We will present the final performance of SAXO obtained during the instrument AIT in Europe as well as the very first on-sky results. The main requirements and system characteristics will be recalled and the full AO loop performance will be quantified and compared to original specifications. It will be demonstrated that SAXO meets or even exceeds (especially its limit magnitude and its jitter residuals) its challenging requirements (more than 90% of SR in H band and a 3 mas residual jitter). Finally, after 10 years of AO developments, from early design to final on-sky implementations, some critical system aspects as well as some important lesson-learned will be presented in the perspective of the future generation of complex AO systems for VLTs and ELTs.

  15. Long-term dynamics of the brown macroalga Lobophora variegata on deep reefs in Curaçao

    NASA Astrophysics Data System (ADS)

    Nugues, M. M.; Bak, R. P. M.

    2008-06-01

    Lobophora variegata occurs in the eulittoral zone and in deep water on coral reefs in Curaçao. An analysis of the long-term (1979-2006) changes in the vertical distribution of the macroalga in permanent quadrats indicated a significant increase in cover of the deepwater community. In 1998, Lobophora covered 1 and 5% of the quadrats at 20 and 30 m, respectively. By 2006, these values had risen to 25 and 18%, precipitating a shift in abundance of corals and macroalgae at both depths. This increase coincided with losses in coral cover, possibly linked to bleaching, disease and storm-related mortality in deep water plating Agaricia corals. In contrast, macroalgae remained relatively rare (<6% cover) on shallower (10 m) and deeper (40 m) reefs despite declines in coral cover also occurring at these depths, illustrating the depth-dependent dynamics of coral reefs. Several hypotheses are suggested to explain these changes.

  16. Electrothermal Annealing (ETA) Method to Enhance the Electrical Performance of Amorphous-Oxide-Semiconductor (AOS) Thin-Film Transistors (TFTs).

    PubMed

    Kim, Choong-Ki; Kim, Eungtaek; Lee, Myung Keun; Park, Jun-Young; Seol, Myeong-Lok; Bae, Hagyoul; Bang, Tewook; Jeon, Seung-Bae; Jun, Sungwoo; Park, Sang-Hee K; Choi, Kyung Cheol; Choi, Yang-Kyu

    2016-09-14

    An electro-thermal annealing (ETA) method, which uses an electrical pulse of less than 100 ns, was developed to improve the electrical performance of array-level amorphous-oxide-semiconductor (AOS) thin-film transistors (TFTs). The practicality of the ETA method was experimentally demonstrated with transparent amorphous In-Ga-Zn-O (a-IGZO) TFTs. The overall electrical performance metrics were boosted by the proposed method: up to 205% for the trans-conductance (gm), 158% for the linear current (Ilinear), and 206% for the subthreshold swing (SS). The performance enhancement were interpreted by X-ray photoelectron microscopy (XPS), showing a reduction of oxygen vacancies in a-IGZO after the ETA. Furthermore, by virtue of the extremely short operation time (80 ns) of ETA, which neither provokes a delay of the mandatory TFTs operation such as addressing operation for the display refresh nor demands extra physical treatment, the semipermanent use of displays can be realized. PMID:27552134

  17. Open Reduction for AO/OTA 81-B3 (Hawkins 3) Talar Neck Fractures: The Natural Delivery Method.

    PubMed

    Simpson, R B; Auston, Darryl A

    2016-03-01

    Fractures of the talar neck with subtalar and tibiotalar joint dislocation (AO/OTA 81-B3) represent a treatment challenge for the orthopedic surgeon. The magnitude of deformity and complexity of the pathoanatomy adds to concerns for soft tissue embarrassment to convey an urgency of surgical intervention. Previous studies have described the several techniques for talar reduction, including medial malleolar osteotomy, posterior Schanz pin manipulation, or posteromedial incision to facilitate relocation at the time of definitive open treatment. We describe a simple technique for stepwise surgical intervention using adjuncts to reduction on the surgical field that facilitate an atraumatic relocation of the displaced body fragment through a standard lateral incision, simplifying fixation of the residual talar neck fracture. A reasonable metaphor for the technique is its similarity to reducing an obstetric shoulder dystocia in the delivery of a newborn infant. PMID:26709817

  18. AO-OCT for in vivo mouse retinal imaging: Application of adaptive lens in wavefornt sensorless aberration correction

    NASA Astrophysics Data System (ADS)

    Bonora, Stefano; Jian, Yifan; Pugh, Edward N.; Sarunic, Marinko V.; Zawadzki, Robert J.

    2014-03-01

    We demonstrate Adaptive optics - Optical Coherence Tomography (OCT) with modal sensorless Adaptive Optics correction with the use of novel Adaptive Lens (AL) applied for in-vivo imaging of mouse retinas. The AL can generate low order aberrations: defocus, astigmatism, coma and spherical aberration that were used in an adaptive search algorithm. Accelerated processing of the OCT data with a Graphic Processing Unit (GPU) permitted real time extraction of image projection total intensity for arbitrarily selected retinal depth plane to be optimized. Wavefront sensorless control is a viable option for imaging biological structures for which AOOCT cannot establish a reliable wavefront that could be corrected by wavefront corrector. Image quality improvements offered by adaptive lens with sensorless AO-OCT was evaluated on in vitro samples followed by mouse retina data acquired in vivo.

  19. [Study on bio-contact oxidation A/O process of Guanting Reservior water under low temperature].

    PubMed

    He, Xing-hai; Wu, Jiang-jin; Chang, Li-chun; Wei, Shu-jun; Ke, Jian-ming

    2004-01-01

    The results of the experiments showed that biological contact A/O process could run steadily under low temperature and had better removal effect for ammonia nitrogen and had some removal effect for COD and TN from water of Guanting Reservoir. When the temperature dropped greatly, removal ratio of ammonia nitrogen dropped evidently, but gradually rose and remained at high removal level at last. Under the conditions of the experiment that the temperature was 0-5 degrees C and influent ammonia nitrogen was about 10 mg/L, ammonia nitrogen removal rate remained more than 95% at last. The change of temperature had no evident influence on removal effect of COD. And the conclusion could be got by microscope that under the temperature at 0-5 degrees C the microorganism in the biofilm still had a good activity. PMID:15330431

  20. Prolonged Mantle Melting Revealed in the Curaçao Lava Formation: Implications for the Origin of the Caribbean Plateau

    NASA Astrophysics Data System (ADS)

    Krawl, K.; Duncan, R. A.; Kent, A. J.; Loewen, M.

    2013-12-01

    The Curaçao Lava Formation (CLF), a ~5 km thick section of submarine-erupted lava flows, hyaloclastites, dikes and sills, provides a ~30 Ma record of the magmatic processes involved in the formation of the Caribbean Large Igneous Province (CLIP). The CLF presents ol-tholeiitic and picritic compositions, exposed along the southern transform margin of the CLIP, that are typical of other in situ and tectonized pieces of this ocean plateau. The wide range of recently acquired 40Ar-39Ar ages (62 to 93 Ma) obtained for the Curaçao lavas contradicts previous proposals that the CLF formed over a relatively short period (1-2 million years), but is similar to extended volcanic histories recorded in Haiti (Dumisseau Fm) and at the Beata Ridge. Petrochemical modeling using MELTS indicates that the CLF rock compositions could have formed by fractional crystallization of high-MgO parental magmas with broadly similar major element contents, generated during multiple melting events over this prolonged period. The persistently flat rare earth element patterns in rocks spanning the full age range of the CLF can be reproduced by 10-30% partial melting of a predominantly depleted mantle source with a minor enriched component. The geochemical and age data and modeling results are consistent with a mantle dynamic model for the CLIP in which lateral displacement of mantle plume head material beneath the Caribbean plateau results from subduction-driven mantle flow, which allows for the generation of magmas from a continuously replenished mantle source over approximately 30 million years. While no subduction influence is seen in CLF compositions, the island does record intrusive, arc-related rocks.

  1. The First AO Classification System for Fractures of the Craniomaxillofacial Skeleton: Rationale, Methodological Background, Developmental Process, and Objectives.

    PubMed

    Audigé, Laurent; Cornelius, Carl-Peter; Di Ieva, Antonio; Prein, Joachim

    2014-12-01

    Validated trauma classification systems are the sole means to provide the basis for reliable documentation and evaluation of patient care, which will open the gateway to evidence-based procedures and healthcare in the coming years. With the support of AO Investigation and Documentation, a classification group was established to develop and evaluate a comprehensive classification system for craniomaxillofacial (CMF) fractures. Blueprints for fracture classification in the major constituents of the human skull were drafted and then evaluated by a multispecialty group of experienced CMF surgeons and a radiologist in a structured process during iterative agreement sessions. At each session, surgeons independently classified the radiological imaging of up to 150 consecutive cases with CMF fractures. During subsequent review meetings, all discrepancies in the classification outcome were critically appraised for clarification and improvement until consensus was reached. The resulting CMF classification system is structured in a hierarchical fashion with three levels of increasing complexity. The most elementary level 1 simply distinguishes four fracture locations within the skull: mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). Levels 2 and 3 focus on further defining the fracture locations and for fracture morphology, achieving an almost individual mapping of the fracture pattern. This introductory article describes the rationale for the comprehensive AO CMF classification system, discusses the methodological framework, and provides insight into the experiences and interactions during the evaluation process within the core groups. The details of this system in terms of anatomy and levels are presented in a series of focused tutorials illustrated with case examples in this special issue of the Journal. PMID:25489387

  2. The Comparison of Compression Hip Screw and Bipolar Hemiarthroplasty for the Treatment of AO Type A2 Intertrochanteric Fractures

    PubMed Central

    Kim, Yee-Suk; Hur, Jae-Seung; Hwang, Kyu-Tae; Choi, Il-Yong

    2014-01-01

    Purpose The purpose of this study was to compare the outcomes of osteosynthesis using compression hip screw fixation versus bipolar hemiarthroplasty in AO type A2 intertrochanteric fractures. Materials and Methods From March 2003 to December 2009, 89 patients were included in this study. They were treated using compression hip screws (43 cases) or bipolar hemiarthroplasty (46 cases). The mean age of patients was 77.7 years (65-94 years) and the mean follow-up period was 5.9 years (1-8.3 years). For comparison of the outcomes in the two groups, statistical analyses were performed with parameters including anesthesia time, operation time, amount of transfusion, hospital stay, general complications, clinical outcome, time of partial weight-bearing using a walker, and radiological failure rate. Results Differences in the amount of transfusion, general complications, and clinical outcome (Merle d'Aubigné and Postel score) were not statistically significant between the two groups. The bipolar hemiarthroplasty group showed better results than the compression hip screw group for anesthesia time and the time of partial weight-bearing using a walker. Radiological failures were observed in hips in one case (2.2%) of bipolar hemiarthroplasty, and in four cases (9.3%) of compression hip screw fixation. Conclusion Among elderly individuals with AO type A2 intertrochanteric fractures, patients treated with bipolar hemiarthroplasty were able to perform early ambulation. However, no significant difference in operation time, amount of postoperative transfusion, clinical results, hospital stay, and radiological failure rate was observed between the bipolar hemiarthroplasty and compression hip screw fixation groups.

  3. Dealing with the forecast of the optical turbulence as a tool to support astronomy assisted by AO facilities

    NASA Astrophysics Data System (ADS)

    Masciadri, Elena; Lascaux, Franck; Fini, Luca

    2015-04-01

    In the context of the research activities related to the forecast of the optical turbulence and the atmospherical parameters being relevant for ground-based astronomy we focus here our attention on two specific topics: 1. pros and cons of different solutions to supply wind speed and direction stratification on the whole atmosphere all along a night to support AO facilities; 2. the necessity of instrumentation for optical turbulence monitoring (vertical profiles on the whole atmosphere) to be used operationally. In the last two decades the development and the use of different vertical profilers covering the whole atmosphere or part of it in application to the astronomy took place. Several instruments based on different principles (with associated pros and cons) have been applied in different contexts in astronomy with a main use in the site characterization and site selection. Time changed and the necessity of the astronomy supported by AO facilities is much more demanding with a diversification of applications. Recently, motivated by a precise necessity related to the identification of an absolute reference to carry out studies on optical turbulence forecasts (MOSE project), we carried out a verification of the reliability of a few instruments that lead us to put in evidence some limitations for a few of them. At the same time such a detailed analysis permitted us to clarify the nature of some astroclimatic parameters. The main conclusion at which we arrived is two-fold. From one side we could trace a list of warnings related to different uses of such instruments. On the other side we could identify open problems that indicate that there is still space for research in the field of turbulence monitoring in application to the astronomy. Some suggestions are proposed.

  4. The First AO Classification System for Fractures of the Craniomaxillofacial Skeleton: Rationale, Methodological Background, Developmental Process, and Objectives

    PubMed Central

    Audigé, Laurent; Cornelius, Carl-Peter; Ieva, Antonio Di; Prein, Joachim

    2014-01-01

    Validated trauma classification systems are the sole means to provide the basis for reliable documentation and evaluation of patient care, which will open the gateway to evidence-based procedures and healthcare in the coming years. With the support of AO Investigation and Documentation, a classification group was established to develop and evaluate a comprehensive classification system for craniomaxillofacial (CMF) fractures. Blueprints for fracture classification in the major constituents of the human skull were drafted and then evaluated by a multispecialty group of experienced CMF surgeons and a radiologist in a structured process during iterative agreement sessions. At each session, surgeons independently classified the radiological imaging of up to 150 consecutive cases with CMF fractures. During subsequent review meetings, all discrepancies in the classification outcome were critically appraised for clarification and improvement until consensus was reached. The resulting CMF classification system is structured in a hierarchical fashion with three levels of increasing complexity. The most elementary level 1 simply distinguishes four fracture locations within the skull: mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). Levels 2 and 3 focus on further defining the fracture locations and for fracture morphology, achieving an almost individual mapping of the fracture pattern. This introductory article describes the rationale for the comprehensive AO CMF classification system, discusses the methodological framework, and provides insight into the experiences and interactions during the evaluation process within the core groups. The details of this system in terms of anatomy and levels are presented in a series of focused tutorials illustrated with case examples in this special issue of the Journal. PMID:25489387

  5. Characterization of OCam and CCD220: the fastest and most sensitive camera to date for AO wavefront sensing

    NASA Astrophysics Data System (ADS)

    Feautrier, Philippe; Gach, Jean-Luc; Balard, Philippe; Guillaume, Christian; Downing, Mark; Hubin, Norbert; Stadler, Eric; Magnard, Yves; Skegg, Michael; Robbins, Mark; Denney, Sandy; Suske, Wolfgang; Jorden, Paul; Wheeler, Patrick; Pool, Peter; Bell, Ray; Burt, David; Davies, Ian; Reyes, Javier; Meyer, Manfred; Baade, Dietrich; Kasper, Markus; Arsenault, Robin; Fusco, Thierry; Diaz-Garcia, José Javier

    2010-07-01

    For the first time, sub-electron read noise has been achieved with a camera suitable for astronomical wavefront-sensing (WFS) applications. The OCam system has demonstrated this performance at 1300 Hz frame rate and with 240×240-pixel frame rate. ESO and JRA2 OPTICON2 have jointly funded e2v technologies to develop a custom CCD for Adaptive Optics (AO) wavefront sensing applications. The device, called CCD220, is a compact Peltier-cooled 240×240 pixel frame-transfer 8-output back-illuminated sensor using the EMCCD technology. This paper demonstrates sub-electron read noise at frame rates from 25 Hz to 1300 Hz and dark current lower than 0.01 e-/pixel/frame. It reports on the comprehensive, quantitative performance characterization of OCam and the CCD220 such as readout noise, dark current, multiplication gain, quantum efficiency, charge transfer efficiency... OCam includes a low noise preamplifier stage, a digital board to generate the clocks and a microcontroller. The data acquisition system includes a user friendly timer file editor to generate any type of clocking scheme. A second version of OCam, called OCam2, was designed offering enhanced performances, a completely sealed camera package and an additional Peltier stage to facilitate operation on a telescope or environmentally rugged applications. OCam2 offers two types of built-in data link to the Real Time Computer: the CameraLink industry standard interface and various fiber link options like the sFPDP interface. OCam2 includes also a modified mechanical design to ease the integration of microlens arrays for use of this camera in all types of wavefront sensing AO system. The front cover of OCam2 can be customized to include a microlens exchange mechanism.

  6. [Carbon/nitrogen Removal and Bacterial Community Structure Change in an A/O Activated Sludge System Under Different Dissolved Oxygen Conditions].

    PubMed

    Chen, Yan; Liu, Guo-hua; Fan, Qiang; Wang, Jun-yan; Qi, Lu; Wang, Hong-chen

    2015-07-01

    Carbon and nitrogen removal performance and microbial community structure under different dissolved oxygen (DO) conditions (3, 2, 1 and 0. 5 mg . L -1) in an anoxic/oxic (A/O) system were investigated. The results showed that the A/O activated sludge system still had an excellent performance in removing carbon and nutrient under low DO condition (0. 5 mg . L-1). The removal rates of chemical oxygen demand (COD), ammonia (NH4+ -N) and total nitrogen (TN) were 89. 7%, 98. 3% and 88. 0% respectively. The PCR-DGGE analysis showed that the bacterial community structure changed greatly under different DO conditions. However, there was still a high bacterial diversity even at low DO level, which ensured the functional stability of the A/O system. On the basis of the results of the phylogenetic tree, bacterial communities were observed to be very abundant, and Proteobacteria was identified as the dominant bacteria. PMID:26489332

  7. Effect of ring size on properties of technetium amine oxime complexes. X-ray structure of TcO/sub 2/Pent(AO)/sub 2/, which contains an unusual eight-membered chelate ring, and TcOEn(AO)/sub 2/

    SciTech Connect

    Jurisson, S.; Aston, K.; Fair, C.K.; Schlemper, E.O.; Sharp, P.R.; Troutner, D.E.

    1987-10-21

    A series of neutral technetium(V) complexes have been synthesized (TcO(AO)/sub 2/, TcOEn(AO)/sub 2/, TcO/sub 2/Bn(AO)/sub 2/, and TcO/sub 2/Pent(AO)/sub 2/) in which the length of the hydrocarbon backbone of the amine oxime ligand is varied to effect chemical changes in the resultant complexes. Pn(AO)/sub 2/, 3,3,9,9-tetramethyl-4,8-diazaundecane-2,10-dione dioxime, is the prototype for these ligands. In this series of technetium(V) complexes in which the overall ring size is varied, both monooxo and trans-dioxo cores are observed, and an unusual eight-member chelate ring with the technetium(V) center is found with TcO/sub 2/Pent(AO)/sub 2/. TcO/sub 2/Pent(AO)/sub 2/ x CHCl/sub 3/, TcCl/sub 6/O/sub 4/C/sub 17/H/sub 33/, crystallizes in the triclinic system, space group P anti 1, with a = 1.418 (2) A, b = 13.940 (7) A, c = 18.992 (10) A, ..cap alpha.. = 69.29 (4)/sup 0/, ..beta.. = 90.00 (3)/sup 0/, ..gamma.. = 83.69 (3)/sup 0/, and Z = 4. TcOEn(AO)/sub 2/, TcO/sub 3/N/sub 4/C/sub 12/H/sub 23/, crystallizes in the orthorhombic system, space group Pbca, with a = 11.581 (2) A, b = 12.596 (4) A, c = 21.155 (3) A, and Z = 8.

  8. Promoter isolation and characterization of GhAO-like1, a Gossypium hirsutum gene similar to multicopper oxidases that is highly expressed in reproductive organs.

    PubMed

    Lambret-Frotté, Julia; Artico, Sinara; Muniz Nardeli, Sarah; Fonseca, Fernando; Brilhante Oliveira-Neto, Osmundo; Grossi-de-Sá, Maria Fatima; Alves-Ferreira, Marcio

    2016-01-01

    Cotton is one of the most economically important cultivated crops. It is the major source of natural fiber for the textile industry and an important target for genetic modification for both biotic stress and herbicide tolerance. Therefore, the characterization of genes and regulatory regions that might be useful for genetic transformation is indispensable. The isolation and characterization of new regulatory regions is of great importance to drive transgene expression in genetically modified crops. One of the major drawbacks in cotton production is pest damage; therefore, the most promising, cost-effective, and sustainable method for pest control is the development of genetically resistant cotton lines. Considering this scenario, our group isolated and characterized the promoter region of a MCO (multicopper oxidase) from Gossypium hirsutum, named GhAO-like1 (ascorbate oxidase-like1). The quantitative expression, together with the in vivo characterization of the promoter region reveals that GhAO-like1 has a flower- and fruit-specific expression pattern. The GUS activity is mainly observed in stamens, as expected considering that the GhAO-like1 regulatory sequence is enriched in cis elements, which have been characterized as a target of reproductive tissue specific transcription factors. Both histological and quantitative analyses in Arabidopsis thaliana have confirmed flower (mainly in stamens) and fruit expression of GhAO-like1. In the present paper, we isolated and characterized both in silico and in vivo the promoter region of the GhAO-like1 gene. The regulatory region of GhAO-like1 might be useful to confer tissue-specific expression in genetically modified plants. PMID:26692462

  9. SRT Evaluation of AIRS Version-6.02 and Version-6.02 AIRS Only (6.02 AO) Products

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Iredell, Lena; Molnar, Gyula; Blaisdell, John

    2012-01-01

    Version-6 contains a number of significant improvements over Version-5. This report compares Version-6 products resulting from the advances listed below to those from Version-5. 1. Improved methodology to determine skin temperature (T(sub s)) and spectral emissivity (Epsilon(sub v)). 2. Use of Neural-net start-up state. 3. Improvements which decrease the spurious negative Version-5 trend in tropospheric temperatures. 4. Improved QC methodology. Version-6 uses separate QC thresholds optimized for Data Assimilation (QC=0) and Climate applications (QC=0,1) respectively. 5. Channel-by-channel clear-column radiances R-hat(sub tau) QC flags. 6. Improved cloud parameter retrieval algorithm. 7. Improved OLR RTA. Our evaluation compared V6.02 and V6.02 AIRS Only (V6.02 AO) Quality Controlled products with those of Version-5.0. In particular we evaluated surface skin temperature T(sub s), surface spectral emissivity Epsilon(sub v), temperature profile T(p), water vapor profile q(p), OLR, OLR(sub CLR), effective cloud fraction alpha-Epsilon, and cloud cleared radiances R-hat(sub tau) . We conducted two types of evaluations. The first compared results on 7 focus days to collocated ECMWF truth. The seven focus days are: September 6, 2002; January 25, 2003; September 29, 2004; August 5, 2005; February 24, 2007; August 10, 2007; and May 30, 2010. In these evaluations, we show results for T(sub s), Epsilon(sub v), T(p), and q(p) in terms of yields, and RMS differences and biases with regard to ECMWF. We also show yield trends as well as bias trends of these quantities relative to ECMWF truth. We also show yields and accuracy of channel by channel QC d values of R-hat(sub tau) for V6.02 and V6.02 AO. Version-5 did not contain channel by channel QC d values of R-hat(sub tau). In the second type of evaluation, we compared V6.03 monthly mean Level-3 products to those of Version-5.0, for four different months: January, April, July, and October; in 3 different years 2003, 2007, and 2011

  10. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 EL-1994-00089 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp blocks of the experiment trays left flange and lower flange appear to be discolored by a dark brown stain. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays upper flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and

  11. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05 EL-1994-00088 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp block of the experiment trays lower flange appears to be discolored by a dark brown stain. The tray flanges also appear to be discolored but with a lighter stain. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays upper flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF

  12. Monitoring Io volcanic activity using the Keck AO system: 2-5μm sunlit and eclipse observations

    NASA Astrophysics Data System (ADS)

    Marchis, F.; de Pater, I.; Le Mignant, D.; Roe, H. G.; Fusco, T.; Graham, J. R.; Prange, R.; Macintosh, B.

    2002-12-01

    Galileo provided us with spectacular images of the volcanically active Io moon over the last 7 years, but we understand little about the physical processes occurring on this moon. Groundbased monitoring programs help characterize the long time evolution of Io's volcanic activity, such as the frequency, spatial distribution and temperature of hot spots and outbursts. Our group started a monitoring program of Io's volcanic activity using the Keck II Adaptive Optics (AO) system and its recently installed near-infrared camera NIRC2. Here we report groundbased observations of Io conducted in December 2001 (UT), at 0.05" resolution (120-140 km on Io) in K', i.e., ~4 times better than HST and than global Galileo NIMS images. Our 1-5 micron data enable us to determine the temperature of individual hot spots, a key parameter for geophysical/volcanic flow models. We will present: i) Io in reflected sunlight in K', L', and M bands. We used Io itself as reference source for the wavefront sensor of the AO system. Our L and M-band images show both reflected sunlight and thermal emission from volcanic hot spots. The contrast of images is enhanced using the MISTRAL deconvolution algorithme. The 12 images taken on 10 days provides a complete survey of Io surface during one full rotation. 26 active hot spots were detected on the entire surface in L band (3.8μm), approximatively three times more in M band (4.7μm). One active hot spot is seen in K band (2.2μm) in the Pele area. A study of individual hot spot (temperature, emission area, nature) will be presented. ii) Io in eclipse. While Io is in Jupiter's shadow, it is invisible to the wavefront sensor, but its hot spots are easily visible in the near-infrared. We imaged Io during the 18 Dec. 2001 eclipse using Ganymede (30" from Io, moving relative to Io at ~0.5"/min) as a reference source. A dozen of faint hot spots are detected at both K' and L', allowing temperature estimates for each of them. Keck Science team is composed of

  13. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 EL-1994-00391 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The paint dots on the experiment tray clamp blocks, originally white, appearsDE:to be discolored by a brown stain. The experiment tray flanges also appear to be coated but with a lighter colored stain. The UHCRE detectors were contained in 16 peripheral LDEF trays with at leastDE:one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The

  14. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05 EL-1994-00311 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after removal of the experiment tray from the LDEF. The experiment tray flanges appear discolored by a brown stain. Outlines of experiment tray clamp blocks are clearly visible on the upper and lower tray flanges. The experiment tray holding fixture hardware covers the clamp block areas on the end flanges. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the

  15. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08 EL-1994-00661 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp block of the experiment trays upper flange and the right end of the experiment trays lower flange appear to be slightly discolored. The tray flanges appear to be discolored by a light brown stain and the ground strap located in the center of the lower flange appears intact but a much darker copper color than in the prelaunch photograph. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored

  16. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02 EL-1994-00385 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The white paint dot on the experiment tray clamp blocks located at the center of the trays lower and left flanges and at the right end of the trays upper flange appear to be discolored by a brown stain. The experiment tray flanges also appear to be coated but with a lighter colored stain. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an

  17. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 EL-1994-00272 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after the experiment tray was removed from the LDEF and the silvered TEFLON® thermal cover removed. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. A copper coated pressure sensitive tape was used to provide an electrical ground strap between the thermal cover and the LDEF structure. All experiment hardware appears to be in prelaunch condition and securely in place. The three cylindrical pressure vessels containing the experiment detectors are shown mounted in the experiment tray with the frame for mounting the

  18. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05 EL-1994-00184 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The paint dots on the experiment tray clamp blocks, originally white, appears to be discolored by a brown stain. The experiment tray flanges also appear to be coated but with a lighter colored stain. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE

  19. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray F04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray F04 EL-1994-00171 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray F04 The postflight photograph was taken in the SAEF II at KSC after the experiment was removed from the LDEF. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact. The circular damaged locations that appeared to to be impact points in the flight photograph are not as apparent in the reflections and is less taut cover. The wrinkled spots on the thermal cover are areas

  20. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C06

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C06 EL-1994-00206 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C06 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after removal of the experiment tray from the LDEF. The experiment tray flanges appear discolored by a light brown stain. Outlines of experiment tray clamp blocks are clearly visible on the lower tray flanges.The experiment tray holding fixture hardware covers the clamp block areas on the end flanges. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays upper flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments

  1. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A02 EL-1994-00387 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A02 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The white paint dot on the experiment tray clamp blocks located at the center of the trays upper and right flanges and at the left end of the trays lower flange appear to be discolored by a brown stain. The experiment tray flanges also appear to be coated but with a lighter colored stain. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar with a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an

  2. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02 EL-1994-00131 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp blocks of the experiment trays left flange and lower flange appear to be slightly discolored. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be intact with out visible

  3. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C05 EL-1994-00205 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C05 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after removal of the experiment tray from the LDEF. The experiment tray flanges appear discolored by a brown stain that provides outlines of the experiment tray clamp blocks that are clearly visible on the upper and lower tray flanges.The experiment tray holding fixture hardware covers the clamp block areas on the end flanges. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground

  4. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10 EL-1994-00122 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in the Orbiter Processing Facility (OPF) at KSC during removal of the LDEF from the Orbiters cargo bay. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays upper flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque (glossy white) with many black dots of various sizes that appear to be impact craters. An impact

  5. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10 EL-1994-00019 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp blocks of the experiment trays left flange and lower flange appear to be slightly discolored. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from

  6. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10 EL-1994-00162 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in the Orbiter Processing Facility during removal of the LDEF from the Orbiter's payload bay. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque with numerous black dots of various sizes that appear to be impact craters. Many of the craters appear to have

  7. A proposed adhesin AoMad1 helps nematode-trapping fungus Arthrobotrys oligospora recognizing host signals for life-style switching.

    PubMed

    Liang, Lianming; Shen, Renfei; Mo, Yuanyuan; Yang, Jinkui; Ji, Xinglai; Zhang, Ke-Qin

    2015-08-01

    The nematode-trapping fungus Arthrobotrys oligospora is an important natural enemy of nematodes. It can capture nematodes by producing a special mycelial structure called adhesive network or trap. The trap is also a signature of the fungus switching from the saprophytic lifestyle to the predacious lifestyle. At present, little is known about the mechanism of lifestyle switch in nematode-trapping fungi. Here we describe the effect of a cell wall protein called AoMad1 on lifestyle switch. The disruption of the AoMad1-encoding gene in A. oligospora resulted in the formation of more traps in the presence of nematodes. Interestingly, the mutant strain was more sensitive to certain nitrogen sources as trap inducers than the wild type strain. The microscopic examinations revealed that the AoMad1-deletion mutant lacked cell surface adhesive materials and the cell wall structures were more porous than wild-type strains. A great of genes were differentially expressed by transcriptomic analysis when trap formation was induced by sodium nitrate compared to the wild type strain, many of them were related to nitrogen metabolism, host-pathogen interaction and mycelia development. The results suggest that AoMad1 plays an important role in life style switching in A. oligospora. PMID:25724687

  8. Cooperativity among defect sites in AO2+x and A4O9 (A=U,Np,Pu) : Density functional calculations

    NASA Astrophysics Data System (ADS)

    Andersson, D. A.; Lezama, J.; Uberuaga, B. P.; Deo, C.; Conradson, S. D.

    2009-01-01

    Actinide dioxides derived from the AO2 fluorite lattice are of high technological relevance due to their application in nuclear reactor fuels. In this paper we use density functional theory calculations to study the oxidation of uranium, neptunium and plutonium dioxides, AO2 ( A=U , Np, or Pu), in O2 and O2/H2O environments. We pay particular attention to the formation of oxygen clusters (cooperativity) in AO2+x and how this phenomenon governs oxidation thermodynamics and the development of ordered A4O9 compounds. The so-called split di-interstitial, composed of two nearest-neighbor octahedral oxygen interstitials that dislocate one regular fluorite lattice oxygen ion to form a cluster of triangular geometry, is predicted to be the fundamental building block of the most stable cluster configurations. We also identify how the formation of oxygen defect clusters and the degree of oxidation in AO2+x are both governed by the ability of the O2p orbitals of the interstitial-like (+x) ions to hybridize with regular fluorite lattice ions.

  9. Since When or How Often? Dissociating the Roles of Age of Acquisition (AoA) and Lexical Frequency in Early Visual Word Processing

    ERIC Educational Resources Information Center

    Adorni, Roberta; Manfredi, Mirella; Proverbio, Alice Mado

    2013-01-01

    The aim of the study was to investigate the effect of both word age of acquisition (AoA) and frequency of occurrence on the timing and topographical distribution of ERP components. The processing of early- versus late-acquired words was compared with that of high-frequency versus low-frequency words. Participants were asked to perform an…

  10. Sea-level history of past interglacial periods from uranium-series dating of corals, Curaçao, Leeward Antilles islands

    NASA Astrophysics Data System (ADS)

    Muhs, Daniel R.; Pandolfi, John M.; Simmons, Kathleen R.; Schumann, R. Randall

    2012-09-01

    Curaçao has reef terraces with the potential to provide sea-level histories of interglacial periods. Ages of the Hato (upper) unit of the "Lower Terrace" indicate that this reef dates to the last interglacial period, Marine Isotope Stage (MIS) 5.5. On Curaçao, this high sea stand lasted at least 8000 yr (~ 126 to ~ 118 ka). Elevations and age of this reef show that late Quaternary uplift rates on Curaçao are low, 0.026-0.054 m/ka, consistent with its tectonic setting. Ages of ~ 200 ka for corals from the older Cortalein unit of the Lower Terrace correlate this reef to MIS 7, with paleo-sea level estimates ranging from - 3.3 m to + 2.3 m. The estimates are in agreement with those for MIS 7 made from other localities and indicate that the penultimate interglacial period was a time of significant warmth, on a par with the present interglacial period. The ~ 400 ka (MIS 11) Middle Terrace I on Curaçao, dated by others, may have formed from a paleo-sea level of + 8.3 to + 10.0 m, or (less likely) + 17 m to + 20 m. The lower estimates are conservative compared to previous studies, but still require major ice sheet loss from Greenland and Antarctica.