BL Lacertae Objects Beyond Redshift 1.3 - UV-to-NIR Photometry and Photometric Redshift for Fermi/LAT Blazars

NASA Technical Reports Server (NTRS)

Rau, A.; Schady, P.; Greiner, J.; Salvato, M.; Ajello, M.; Bottacini, E.; Gehrels, N.; Afonso, P. M. J.; Elliott, J.; Filgas, R.;

Testing the Pairs-Reflection Model with X-Ray Spectral Variability and X-Ray Properties of Complete Samples of Radio-Selected BL Lacertae Objects

NASA Astrophysics Data System (ADS)

Urry, C. Megan

1997-01-01

This grant was awarded to Dr. C. Megan Urry of the Space Telescope Science Institute in response to two successful ADP proposals to use archival Ginga and Rosat X-ray data for 'Testing the Pairs-Reflection model with X-Ray Spectral Variability' (in collaboration with Paola Grandi, now at the University of Rome) and 'X-Ray Properties of Complete Samples of Radio-Selected BL Lacertae Objects' (in collaboration with then-graduate student Rita Sambruna, now a post-doc at Goddard Space Flight Center). In addition, post-docs Joseph Pesce and Elena Pian, and graduate student Matthew O'Dowd, have worked on several aspects of these projects. The grant was originally awarded on 3/01/94; this report covers the full period, through May 1997. We have completed our project on the X-ray properties of radio-selected BL Lacs.

Radio outburst of BL Lacertae

NASA Astrophysics Data System (ADS)

Buemi, C. S.; Leto, P.; Trigilio, C.; Umana, G.; Giroletti, M.; Orienti, M.; Raiteri, C. M.; Villata, M.; Bach, U.

2013-04-01

We report on extremely high radio flux of BL Lacertae at 43 and 8 GHz. Observations at 43 GHz with the 32 m radio telescope in Noto (Italy) revealed a flux density of 10.5 +/- 0.2 Jy on 2013 April 10.65, while observations at 8 GHz with the 32 m radio telescope in Medicina (Italy) detected a flux density of 8.2 +/- 0.7 Jy on April 12.22. These extremely high radio fluxes show that the radio activity likely correlated to the strong optical, near-infrared, and gamma-ray activity of 2011-2012 (see ATels #4028, #4031, #4155, #4271, #4277, #4349, #4565, #4600), and X-ray activity of late 2012 (ATels #4557, #4627), is far to be exhausted.

Besnoitia in a palaearctic lizard (Lacerta dugesii) from Madeira.

PubMed

Frank, W; Frenkel, J K

1981-01-01

Besnoitia cysts in the heart of a lizard (Lacerta dugesii) from the islands of Madeira are the first record of besnoitiosis in a poikilothermic animal in the Old World. The size of the cysts corresponds to those found in lizard genera (Basiliscus and Ameiva) from Panama which belong to B. darlingi. Up to now nothing is known concerning the life cycle of this species from Madeira but it seems possible that cats function as definitive hosts as well as in the other species.

IUE observations of extragalactic objects

NASA Technical Reports Server (NTRS)

Boksenberg, A.; Snijders, M. A. J.; Wilson, R.; Benvenuti, P.; Clavell, J.; Macchetto, F.; Penston, M.; Boggess, A.; Gull, T. R.; Gondhalekar, P.

1978-01-01

During the commissioning phase of IUE several extragalactic objects were observed spectrally at low dispersion in the UV range lambda lambda 1150-3200: the Seyfert galaxies NGC4151 and NGC1068, the QSO 3C273, the BL Lacertae object B2 1101+38, the giant elliptical galaxy M87 and the spiral galaxy M81. The results obtained are presented and a preliminary analysis given for all six objects, discussing the continuous spectrum, extinction, emission line spectrum and absorption line spectrum, where possible for each case. Several new or confirmatory astrophysical results are obtained.

Clustering environments of BL Lac objects

NASA Technical Reports Server (NTRS)

Wurtz, Ronald; Ellingson, Erica; Stocke, John T.; Yee, H. K. C.

1993-01-01

We report measurements of the amplitude of the BL Lac galaxy spatial covariance function, B(gb), for the fields of five BL Lacertae objects. We present evidence for rich clusters around MS 1207+39 and MS 1407+59, and confirm high richness for the cluster containing H0414+009. We discuss the ease of 3C 66 A and find evidence for a poor cluster based on an uncertain redshift of z = 0.444. These data suggest that at least some BL Lac objects are consistent with being FR 1 radio galaxies in rich clusters.

One-milliarsecond precision parallax studies in the regions of Delta Cephei and EV Lacertae

NASA Technical Reports Server (NTRS)

Gatewood, George; De Jonge, Kiewiet Joost; Stephenson, Bruce

1993-01-01

Trigonometric parallaxes for stars in the regions of the variable stars delta Cephei and EV Lacertae are derived from data collected with the Multichannel Astrometric Photometer (MAP) and the Thaw Refractor of the University of Pittsburgh's Allegheny Observatory. The weighted mean parallax of all trigonometric studies of delta Cephei is now + 0.0030 sec + or - 0.00093 sec, corresponding to a distance modulus of 7.61 + or - 0.67 mag. This indicates that this luminosity standard star is approximately one standard deviation more distance than has been generally accepted. The weighted mean trigonometric parallax of all studies of the variable star EV Lacertae (BD + 43 deg 4305) is + 0.1993 sec + or - 0.00093 sec, implying a distance modulus of - 1.498 + or - 0.0010 mag. The calculated absolute magnitude of this star is almost exactly that predicted by its (R-I)(sub Kron) magnitude and by the Gliese (R-I) main-sequence value for stars in the solar neighborhood. We also find a parallax of 0.0189 sec + or - 0.0008 sec for the FO IVn star, HR 8666 (BD + 43 sec 4300). The derived luminosity of this star is midway between that expected for luminosity class IV and V stars at the indicated temperature.

Optical polarization of high-energy BL Lacertae objects

NASA Astrophysics Data System (ADS)

Hovatta, T.; Lindfors, E.; Blinov, D.; Pavlidou, V.; Nilsson, K.; Kiehlmann, S.; Angelakis, E.; Fallah Ramazani, V.; Liodakis, I.; Myserlis, I.; Panopoulou, G. V.; Pursimo, T.

2016-12-01

Context. We investigate the optical polarization properties of high-energy BL Lac objects using data from the RoboPol blazar monitoring program and the Nordic Optical Telescope. Aims: We wish to understand if there are differences between the BL Lac objects that have been detected with the current-generation TeV instruments and those objects that have not yet been detected. Methods: We used a maximum-likelihood method to investigate the optical polarization fraction and its variability in these sources. In order to study the polarization position angle variability, we calculated the time derivative of the electric vector position angle (EVPA) change. We also studied the spread in the Stokes Q/I-U/I plane and rotations in the polarization plane. Results: The mean polarization fraction of the TeV-detected BL Lacs is 5%, while the non-TeV sources show a higher mean polarization fraction of 7%. This difference in polarization fraction disappears when the dilution by the unpolarized light of the host galaxy is accounted for. The TeV sources show somewhat lower fractional polarization variability amplitudes than the non-TeV sources. Also the fraction of sources with a smaller spread in the Q/I-U/I plane and a clumped distribution of points away from the origin, possibly indicating a preferred polarization angle, is larger in the TeV than in the non-TeV sources. These differences between TeV and non-TeV samples seem to arise from differences between intermediate and high spectral peaking sources instead of the TeV detection. When the EVPA variations are studied, the rate of EVPA change is similar in both samples. We detect significant EVPA rotations in both TeV and non-TeV sources, showing that rotations can occur in high spectral peaking BL Lac objects when the monitoring cadence is dense enough. Our simulations show that we cannot exclude a random walk origin for these rotations. Conclusions: These results indicate that there are no intrinsic differences in the

A Search for Low-Luminosity BL Lacertae Objects

NASA Astrophysics Data System (ADS)

Rector, Travis A.; Stocke, John T.; Perlman, Eric S.

1999-05-01

Many properties of BL Lacs have become explicable in terms of the ``relativistic beaming'' hypothesis, whereby BL Lacs are FR 1 radio galaxies viewed nearly along the jet axis. However, a possible problem with this model is that a transition population between beamed BL Lacs and unbeamed FR 1 galaxies has not been detected. A transition population of ``low-luminosity BL Lacs'' was predicted to exist in abundance in X-ray-selected samples such as the Einstein Extended Medium Sensitivity Survey (EMSS) by Browne & Marcha. However, these BL Lacs may have been misidentified as clusters of galaxies. We have conducted a search for such objects in the EMSS with the ROSAT High-Resolution Imager (HRI) here we present ROSAT HRI images, optical spectra, and VLA radio maps for a small number of BL Lacs that were previously misidentified in the EMSS catalog as clusters of galaxies. While these objects are slightly lower in luminosity than other EMSS BL Lacs, their properties are too similar to the other BL Lacs in the EMSS sample to ``bridge the gap'' between BL Lacs and FR 1 radio galaxies. Also, the number of new BL Lacs found is too low to alter significantly the X-ray luminosity function or value for the X-ray-selected EMSS BL Lac sample. Thus, these observations do not explain fully the discrepancy between the X-ray- and radio-selected BL Lac samples.

Optical and radio properties of X-ray selected BL Lacertae objects

NASA Technical Reports Server (NTRS)

Stocke, J. T.; Liebert, J.; Schmidt, G.; Gioia, I. M.; Maccacaro, T.

1985-01-01

The eight BL Lac objects from the HEAO 1 A-2 all-sky survey and from the Einstein medium-sensitivity survey (MSS) form a flux-limited complete X-ray selected sample. The optical and radio properties of the MSS BL Lac objects are presented and compared with those of the HEAO 1 A-2 sample and with those of radio-selected BL Lac objects. The X-ray selected BL Lac objects possess smaller polarized fractions and less violent optical variability than radio-selected BL Lac objects. These properties are consistent with the substantial starlight fraction seen in the optical spectra of a majority of these objects. This starlight allows a determination of definite redshifts for two of four MSS BL Lac objects and a probable redshift for a third. These redshifts are 0.2, 0.3, and 0.6. Despite the differences in characteristics between the X-ray selected and radio-selected samples, it is concluded that these eight objects possess most of the basic qualities of BL Lac objects and should be considered members of that class. Moreover, as a class, these X-ray selected objects have the largest ratio of X-ray to optical flux of any active galactic nuclei yet discovered.

Probing the Innermost Regions of AGN Jets and Their Magnetic Fields with RadioAstron. I. Imaging BL Lacertae at 21 Microarcsecond Resolution

NASA Astrophysics Data System (ADS)

Gómez, José L.; Lobanov, Andrei P.; Bruni, Gabriele; Kovalev, Yuri Y.; Marscher, Alan P.; Jorstad, Svetlana G.; Mizuno, Yosuke; Bach, Uwe; Sokolovsky, Kirill V.; Anderson, James M.; Galindo, Pablo; Kardashev, Nikolay S.; Lisakov, Mikhail M.

2016-02-01

We present the first polarimetric space very long baseline interferometry (VLBI) imaging observations at 22 GHz. BL Lacertae was observed in 2013 November 10 with the RadioAstron space VLBI mission, including a ground array of 15 radio telescopes. The instrumental polarization of the space radio telescope is found to be less than 9%, demonstrating the polarimetric imaging capabilities of RadioAstron at 22 GHz. Ground-space fringes were obtained up to a projected baseline distance of 7.9 Earth diameters in length, allowing us to image the jet in BL Lacertae with a maximum angular resolution of 21 μas, the highest achieved to date. We find evidence for emission upstream of the radio core, which may correspond to a recollimation shock at about 40 μas from the jet apex, in a pattern that includes other recollimation shocks at approximately 100 and 250 μas from the jet apex. Polarized emission is detected in two components within the innermost 0.5 mas from the core, as well as in some knots 3 mas downstream. Faraday rotation analysis, obtained from combining RadioAstron 22 GHz and ground-based 15 and 43 GHz images, shows a gradient in rotation measure and Faraday-corrected polarization vector as a function of position angle with respect to the core, suggesting that the jet in BL Lacertae is threaded by a helical magnetic field. The intrinsic de-boosted brightness temperature in the unresolved core exceeds 3× {10}12 K, suggesting, at the very least, departure from equipartition of energy between the magnetic field and radiating particles.

AoS28D, a proline-Xaa carboxypeptidase secreted by Aspergillus oryzae.

PubMed

Salamin, Karine; Eugster, Philippe J; Jousson, Olivier; Waridel, Patrice; Grouzmann, Eric; Monod, Michel

2017-05-01

Prolyl peptidases of the MEROPS S28 family are of particular interest because they are key enzymes in the digestion of proline-rich peptides. A BLAST analysis of the Aspergillus oryzae genome revealed sequences coding for four proteases of the S28 family. Three of these proteases, AoS28A, AoS28B, and AoS28C, were previously characterized as acidic prolyl endopeptidases. The fourth protease, AoS28D, showed high sequence divergence with other S28 proteases and belongs to a phylogenetically distinct cluster together with orthologous proteases from other Aspergillus species. The objective of the present paper was to characterize AoS28D protease in terms of substrate specificity and activity. AoS28D produced by gene overexpression in A. oryzae and in Pichia pastoris was a 70-kDa glycoprotein with a 10-kDa sugar moiety. In contrast with other S28 proteases, AoS28D did not hydrolyze internal Pro-Xaa bonds of several tested peptides. Similarly, to human lysosomal Pro-Xaa carboxypeptidase, AoS28D demonstrated selectivity for cleaving C-terminal Pro-Xaa bonds which are resistant to carboxypeptidases of the S10 family concomitantly secreted by A. oryzae. Therefore, AoS28D could act in synergy with these enzymes during sequential degradation of a peptide from its C-terminus.

The Cosmic Evolution of Fermi BL Lacertae Objects

NASA Astrophysics Data System (ADS)

Ajello, Marco; Gasparrini, Dario; Romani, Roger W.; Shaw, Michael S.

2014-06-01

It has been notoriously difficult in the past to measure the cosmological evolution of BL Lacs because of the challenges related to measure their redshift. Extensive optical follow-up observations of a sample of ~200 Fermi-detected BL Lac objects have provided much-needed redshift information for many of them. This stands as the largest and most complete sample of BL Lacs available in the literature and was used to determine the cosmological properties of this elusive source class. This talk will review the cosmic evolution of BL Lacs and discuss the link to their siblings flat-spectrum radio quasars (FSRQs). Evidence suggests that BL Lacs of the high-synchrotron peaked class might be an accretion-starved end-state of an earlier merger-driven gas-rich phase.

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

Borrelia lusitaniae and Green Lizards (Lacerta viridis), Karst Region, Slovakia

PubMed Central

Majláth, Igor; Derdáková, Marketa; Víchová, Bronislava; Peťko, Branislav

2006-01-01

In Europe, spirochetes within the Borrelia burgdorferi sensu lato complex are transmitted by Ixodes ricinus ticks. Specific associations are described between reservoir hosts and individual genospecies. We focused on green lizard (Lacerta viridis) as a host for ticks and potential host for borreliae. In 2004 and 2005, a total of 146 green lizards infested by ticks were captured, and 469 I. ricinus ticks were removed. Borrelial infection was detected in 16.6% of ticks from lizards. Of 102 skin biopsy specimens collected from lizards, 18.6% tested positive. The most frequently detected genospecies was B. lusitaniae (77.9%–94.7%). More than 19% of questing I. ricinus collected in areas where lizards were sampled tested positive for borreliae. B. garinii was the dominant species, and B. lusitaniae represented 11.1%. The presence of B. lusitaniae in skin biopsy specimens and in ticks that had fed on green lizards implicates this species in the transmission cycle of B. lusitaniae. PMID:17326941

On the surface density of X-ray selected BL Lacertae objects

NASA Technical Reports Server (NTRS)

Maccacaro, T.; Gioia, I. M.; Maccagni, D.; Stocke, J. T.

1984-01-01

Only a handful of BL Lac objects have been found as a result of systematic optical identification of serendipitous Einstein X-ray sources. By combining the data from two flux-limited complete X-ray surveys (the HEAO 1 A-2 and the Einstein Observatory Medium Sensitivity Survey) the surface density of X-ray emitting BL Lac objects is evaluated as a function of their X-ray flux. It is found that a single power law is not an acceptable representation of the BL Lac objects' X-ray log N-log S. The number-flux relationship is consistent with the Euclidean slope at 'high' flux levels but shows a drastic flattnring below fluxes of the order of 10 to the -12th ergs per sq cm/s. The implications of this result are briefly discussed with respect to the luminosity function, the cosmological evolution, and the X-ray to optical flux ratio in BL Lac objects.

Photometric monitoring of three BL Lacertae objects in 1993-1998

NASA Astrophysics Data System (ADS)

Bai, J. M.; Xie, G. Z.; Li, K. H.; Zhang, X.; Liu, W. W.

1999-05-01

The results of optical photometric (BVRI) monitoring of three BL Lac objects over a time interval of about four years are presented. The sources are three classical radio-selected BL Lac objects, BL Lac, OJ 287 and PKS 0735+178. During our observation OJ 287 was in the stage of a large periodic outburst which consisted of at least two peaks. Almost all the observations obtained over consecutive nights detected intranight variations. In 1995 and 1996 BL Lac kept in faint states, with fewer and smaller rapid flares and fluctuations. On the contrary, in late 1997 BL Lac was at the stage of a large outburst, accompanied with much more large amplitude rapid flares and fluctuations. PKS 0735+178 was almost at its faint end from 1994 to early 1998. Over this time interval, the intraday variations and microvariations in PKS 0735+178 were rare and the amplitude was very small, except a rapid darkening of ~ 0.4 mag on 24 January 1995. Previous work by \\cite[Webb et al. (1988);]{web88} \\cite[Wagner et al. (1996);]{wag96} \\cite[Pian et al. (1997)]{pia97} also showed the same behaviour of variability as BL Lac and PKS 0735+178 in BL Lac, S5 0716+714, PKS 2155-304, respectively. We propose that the motion of orientation of the relativistic jet in a BL Lac object be responsible for these variability behaviours. Table~1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

Metabolic adaptations of overwintering European common lizards (Lacerta vivipara).

PubMed

Voituron, Y; Hérold, J P; Grenot, C

2000-01-01

The European common lizard Lacerta vivipara, a reptile of cold-temperate climates, provides us an interesting model of low-temperature adaptation. Indeed its unique cold-hardiness strategy, which employs both freeze tolerance and freeze avoidance, may be seen as the primary reason for its large distribution, which extends from Spain to beyond the Arctic circle. To study the metabolism supporting this capacity, we used three techniques: two techniques of calorimetry (oxygen consumption and thermogenesis) and nuclear magnetic resonance spectroscopy. These techniques were used to examine the metabolic balance and the different molecular pathways used between three different periods through the year (September, January, and May). The results show a significant 20% augmentation of winter anaerobic metabolism compared to other periods of the year. This is mainly because of an activation of the lactic fermentation pathway leading to an increase of lactate concentration (>34% in winter). Furthermore, glucose, which increases some 245% in winter, is used as antifreeze and metabolic substrate. Furthermore, this study provides evidence that the physiological adaptations of the common lizard differ from those of other ectotherms such as Rana sylvatica. Concentrations of alanine and glycerol, commonly used as antifreeze by many overwintering ectotherms, do not increase during winter.

Radio constraints on the nature of BL Lacertae objects and their parent population

NASA Technical Reports Server (NTRS)

Kollgaard, R. I.; Wardle, J. F. C.; Roberts, D. H.; Gabuzda, D. C.

1992-01-01

5 GHz VLA observations of 17 BL Lac objects with bright radio cores at both high and low resolution are reported. Extended emission is detected around most objects. None of the sources observed at low resolution show evidence of giant halos on the scale of tens of arcmin. In general, the sources with the most luminous extended emission exhibit FR II characteristics in both morphology and polarization, and less luminous sources exhibit FR I characteristics. Thus, the parent population of the BL Lac objects contains both FR I and FR II radio sources. No BL Lac objects are found that clearly exhibit quasarlike polarization at milliarcsec resolution. This argues against the view that the more luminous BL Lac objects are simply an extension of the quasar/OVV population, or that most BL Lac objects are gravitationally microlensed images of distant quasars. Other properties are generally consistent with the view the BL Lac objects are normal radio galaxies whose jets make a small angle to the line of sight.

Spectroscopic monitoring of the BL Lac object AO 0235+164

NASA Astrophysics Data System (ADS)

Raiteri, C. M.; Villata, M.; Capetti, A.; Heidt, J.; Arnaboldi, M.; Magazzù, A.

2007-03-01

Aims:Spectroscopic monitoring of BL Lac objects is a difficult task that nonetheless can provide important information on the different components of the active galactic nucleus. Methods: We performed optical spectroscopic monitoring of the BL Lac object AO 0235+164 (z=0.94) with the VLT and TNG telescopes from Aug. 2003 to Dec. 2004, during an extended WEBT campaign. The flux of this source is both contaminated and absorbed by a foreground galactic system at z=0.524, the stars of which can act as gravitational micro-lenses. Results: In this period the object was in an optically faint, though variable state, and a broad Mg II emission line was visible at all epochs. The spectroscopic analysis reveals an overall variation in the Mg II line flux of a factor 1.9, while the corresponding continuum flux density changed by a factor 4.3. Most likely, the photoionising radiation can be identified with the emission component that was earlier recognised to be present as a UV-soft-X-ray bump in the source spectral energy distribution and that is visible in the optical domain only in very faint optical states. We estimate an upper limit to the broad line region (BLR) size of a few light months from the historical minimum brightness level; from this we infer the maximum amplification of the Mg II line predicted by the microlensing scenario. Conclusions: .Unless we have strongly overestimated the size of the BLR, only very massive stars could significantly magnify the broad Mg II emission line, but the time scale of variations due to these (rare) events would be of several years. In contrast, the continuum flux, coming from much smaller emission regions in the jet, could be affected by microlensing from the more plausible MACHO deflectors, with variability time scales of the order of some months. Based on observations collected at the European Southern Observatory, Chile (ESO Programme 71.A-0174), and on observations made with the Italian Telescopio Nazionale Galileo (TNG

Finding the rarest objects in the universe: A new, efficient method for discovering BL Lacertae objects

NASA Technical Reports Server (NTRS)

Stocke, John; Perlman, Eric; Granados, Arno; Schachter, Jonathan; Elvis, Martin; Urry, Meg; Impey, Chris; Smith, Paul

1993-01-01

We present a new, efficient method for discovering new BL Lac Objects based upon the results of the Einstein Extended Medium Sensitivity Survey (EMSS). We have found that all x-ray selected BL Lacs are radio emitters, and further, that in a 'color-color' diagram (radio/optical and optical/x-ray) the BL Lac Objects occupy an area distinct from both radio loud quasars and the radio quiet QSOs and Seyferts which dominate x-ray selected samples. After obtaining radio counterparts via VLA 'snapshot' observations of a large sample of unidentified x-ray sources, the list of candidates is reduced. These candidates then can be confirmed with optical spectroscopy and/or polarimetry. Since greater than 70 percent of these sources are expected to be BL Lacs, the optical observations are very efficient. We have tested this method using unidentified sources found in the Einstein Slew Survey. The 162 Slew Survey x-ray source positions were observed with the VLA in a mixed B/C configuration at 6 cm resulting in 60 detections within 1.5 position error circle radii. These x-ray/optical/radio sources were then plotted, and 40 BL Lac candidates were identified. To date, 10 candidates have been spectroscopically observed resulting in 10 new BL Lac objects! Radio flux, optical magnitude, and polarization statistics (obtained in white light with the Steward Observatory 2.3 m CCD polarimeter) for each are given.

Optical and UV spectroscopy of the peculiar RS CVn system RT Lacertae

NASA Technical Reports Server (NTRS)

Huenemoerder, D. P.; Barden, S. C.

1986-01-01

H-alpha and H-beta spectra of the peculiar double-lined RS CVn binary RT Lacertae have been obtained using the IUE, together with a ground-based coude-feed telescope at KPNO. The ground-based spectra show an asymmetry related to the orbital phase in the H-alpha profile. H-beta profiles showed excess emission in one hemisphere and excess absorption in the other, with a broad Gaussian emission component superposed on the excess H-alpha line. A radial velocity curve was derived to estimate the mass ratio and geometry of the system. It is shown that the component of RT Lac fills 80-90 percent of the equilibrium Roche surface. Low-resolution ultraviolet data show that the supposed cooler component is bluer than its companion, suggesting evidence of a scattering shell or a cloud produced by the splash of a gas stream. The phase behavior of the low resolution ultraviolet data support the conclusion that RT Lac is a mass transfer system and that mass transfer is the primary cause of its activity.

Extraordinary Activity in the BL Lacertae Object OJ 287

NASA Astrophysics Data System (ADS)

Hughes, Philip A.; Aller, Hugh D.; Aller, Margo F.

1998-08-01

We use a continuous wavelet transform to analyze more than two decades of data for the BL Lac object OJ 287 acquired as part of the University of Michigan Radio Astronomy Observatory (UMRAO) variability program. We find clear evidence for a persistent modulation of the total flux and polarization with period ~1.66 yr and for another signal that dominates activity in the 1980s with period ~1.12 yr. The relationship between these two variations can be understood in terms of a ``shock-in-jet'' model, in which the longer timescale periodicity is associated with an otherwise quiescent jet and the shorter timescale activity is associated with the passage of a shock. The different periodicities of these two components may reflect different internal conditions of the two flow domains leading to different wave speeds or different contractions of a single underlying periodicity due to the different Doppler factors of the two flow components. We suggest that the modulation arises from a wave driven by some asymmetric disturbance close to the central engine. The periodic behavior in polarization exhibits excursions in U that correspond to a direction ~45° from the VLBI jet axis. This behavior is not explained by the random walk in the Q-U plane that is expected from models in which a pattern of randomly aligned magnetic field elements propagate across the visible portion of the flow and suggests a small amplitude, cyclic variation in the flow direction in that part of the flow that dominates centimeter wavelength emission.

Multiwavelength Observations of the Blazar BL Lacertae: A New Fast TeV Gamma-Ray Flare

NASA Astrophysics Data System (ADS)

Abeysekara, A. U.; Benbow, W.; Bird, R.; Brantseg, T.; Brose, R.; Buchovecky, M.; Buckley, J. H.; Bugaev, V.; Connolly, M. P.; Cui, W.; Daniel, M. K.; Falcone, A.; Feng, Q.; Finley, J. P.; Fortson, L.; Furniss, A.; Gillanders, G. H.; Gunawardhana, I.; Hütten, M.; Hanna, D.; Hervet, O.; Holder, J.; Hughes, G.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kertzman, M.; Krennrich, F.; Lang, M. J.; Lin, T. T. Y.; McArthur, S.; Moriarty, P.; Mukherjee, R.; O’Brien, S.; Ong, R. A.; Otte, A. N.; Park, N.; Petrashyk, A.; Pohl, M.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Rulten, C.; Sadeh, I.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Wakely, S. P.; Weinstein, A.; Wells, R. M.; Wilcox, P.; Williams, D. A.; Zitzer, B.; The VERITAS Collaboration; Jorstad, S. G.; Marscher, A. P.; Lister, M. L.; Kovalev, Y. Y.; Pushkarev, A. B.; Savolainen, T.; Agudo, I.; Molina, S. N.; Gómez, J. L.; Larionov, V. M.; Borman, G. A.; Mokrushina, A. A.; Tornikoski, M.; Lähteenmäki, A.; Chamani, W.; Enestam, S.; Kiehlmann, S.; Hovatta, T.; Smith, P. S.; Pontrelli, P.

2018-04-01

Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of ∼2.3 hr and a decay time of ∼36 min. The peak flux above 200 GeV is (4.2 ± 0.6) × 10‑6 photon m‑2 s‑1 measured with a 4-minute-binned light curve, corresponding to ∼180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks.

EGRET observations of the BL Lacertae objects 0716+714 and 0521-365

NASA Technical Reports Server (NTRS)

Lin, Y. C.; Bertsch, D. L.; Dingus, B. L.; Esposito, J. A.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Mayer-Hasselwander, H. A.

1995-01-01

During the Compton Observatory's viewing programs Phase 1 (1991 April to 1992 November, also known as the All-Sky Survey) and Phase 2 (1992 November to 1993 September), the BL Lac object 0716+714 was in the field of view of the EGRET telescope a total of six times, three times in Phase 1 and three more times in Phase 2, while the BL Lac object 0521-365 was in the field of view of EGRET only once in Phase 1. The source 0716+714 was detected in high-energy gamma rays by EGRET at a flux level of (2.0 +/- 0.4) x 10(exp -7) photons/sq cm/s for E greater than 100 MeV with a 6 sigma significance when it was first observed by EGRET in 1992 January 10 to 23. The corresponding spectral slope of the photon number distribution is determined to be -2.04 +/- 0.33. The gamma-ray flux of 0716+714 showed considerable time variability in subsequent EGRET observations. But the spectral slope stayed about the same within the statistical uncertainties of the EGRET data. The average spectral slope of the four viewing periods during which the photon flux of 0716+714 stayed above the EGRET detection threshold is found to be -1.85 +/- 0.20 from the combined data. The source 0521+365 was detected by EGRET in 1992 May 14 to June 4 at a flux level of (1.8 +/- 0.5) x 10(exp -7) photons/sq cm/s for E greater than 100 MeV with a 4 sigma significance. The corresponding spectral slope of the photon number distribution is found to be 2.16 +/- 0.36. Details of the observations of these two BL Lac objects with the EGRET telescope are presented.

The intraday variability in the radio-selected and X-ray-selected BL Lacertae objects

NASA Astrophysics Data System (ADS)

Bai, J. M.; Xie, G. Z.; Li, K. H.; Zhang, X.; Liu, W. W.

1998-10-01

Seven BL Lac objects have been photometrically observed in an effort to study the difference of optical intraday variability between the radio-selected BL Lac objects (RBLs) and X-ray-selected BL Lac objects (XBLs). The objects we observed are selected arbitrarily. They are four RBLs, PKS 0735+178, PKS 0754+101, OJ 287 and BL Lac, and three XBLs, H 0323+022, H 0548-322 and H 2154-304. During the observation all of them exhibited microvariation, and H 0323+022 and H 0548-322 sometimes showed brightness oscillation. PKS 0735+178 and BL Lac were in their faint states and not very active. It seems that RBLs do not show microvariability more frequently than XBLs. Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)

Location of γ-ray Flare Emission in the Jet of the BL Lacertae Object OJ287 More than 14 pc from the Central Engine

NASA Astrophysics Data System (ADS)

Agudo, Iván; Jorstad, Svetlana G.; Marscher, Alan P.; Larionov, Valeri M.; Gómez, José L.; Lähteenmäki, Anne; Gurwell, Mark; Smith, Paul S.; Wiesemeyer, Helmut; Thum, Clemens; Heidt, Jochen; Blinov, Dmitriy A.; D'Arcangelo, Francesca D.; Hagen-Thorn, Vladimir A.; Morozova, Daria A.; Nieppola, Elina; Roca-Sogorb, Mar; Schmidt, Gary D.; Taylor, Brian; Tornikoski, Merja; Troitsky, Ivan S.

2011-01-01

We combine time-dependent multi-waveband flux and linear polarization observations with submilliarcsecond-scale polarimetric images at λ = 7 mm of the BL Lacertae type blazar OJ287 to locate the γ-ray emission in prominent flares in the jet of the source >14 pc from the central engine. We demonstrate a highly significant correlation between the strongest γ-ray and millimeter-wave flares through Monte Carlo simulations. The two reported γ-ray peaks occurred near the beginning of two major millimeter-wave outbursts, each of which is associated with a linear polarization maximum at millimeter wavelengths. Our very long baseline array observations indicate that the two millimeter-wave flares originated in the second of two features in the jet that are separated by >14 pc. The simultaneity of the peak of the higher-amplitude γ-ray flare and the maximum in polarization of the second jet feature implies that the γ-ray and millimeter-wave flares are cospatial and occur >14 pc from the central engine. We also associate two optical flares, accompanied by sharp polarization peaks, with the two γ-ray events. The multi-waveband behavior is most easily explained if the γ-rays arise from synchrotron self-Compton scattering of optical photons from the flares. We propose that flares are triggered by interaction of moving plasma blobs with a standing shock. The γ-ray and optical emission is quenched by inverse Compton losses as synchrotron photons from the newly shocked plasma cross the emission region. The millimeter-wave polarization is high at the onset of a flare, but decreases as the electrons emitting at these wavelengths penetrate less polarized regions.

LOCATION OF {gamma}-RAY FLARE EMISSION IN THE JET OF THE BL LACERTAE OBJECT OJ287 MORE THAN 14 pc FROM THE CENTRAL ENGINE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agudo, Ivan; Jorstad, Svetlana G.; Marscher, Alan P.

We combine time-dependent multi-waveband flux and linear polarization observations with submilliarcsecond-scale polarimetric images at {lambda} = 7 mm of the BL Lacertae type blazar OJ287 to locate the {gamma}-ray emission in prominent flares in the jet of the source >14 pc from the central engine. We demonstrate a highly significant correlation between the strongest {gamma}-ray and millimeter-wave flares through Monte Carlo simulations. The two reported {gamma}-ray peaks occurred near the beginning of two major millimeter-wave outbursts, each of which is associated with a linear polarization maximum at millimeter wavelengths. Our very long baseline array observations indicate that the two millimeter-wavemore » flares originated in the second of two features in the jet that are separated by >14 pc. The simultaneity of the peak of the higher-amplitude {gamma}-ray flare and the maximum in polarization of the second jet feature implies that the {gamma}-ray and millimeter-wave flares are cospatial and occur >14 pc from the central engine. We also associate two optical flares, accompanied by sharp polarization peaks, with the two {gamma}-ray events. The multi-waveband behavior is most easily explained if the {gamma}-rays arise from synchrotron self-Compton scattering of optical photons from the flares. We propose that flares are triggered by interaction of moving plasma blobs with a standing shock. The {gamma}-ray and optical emission is quenched by inverse Compton losses as synchrotron photons from the newly shocked plasma cross the emission region. The millimeter-wave polarization is high at the onset of a flare, but decreases as the electrons emitting at these wavelengths penetrate less polarized regions.« less

Optical and UV spectroscopy of the peculiar RS CVn system, RT Lacertae

NASA Technical Reports Server (NTRS)

Huenemoerder, D. P.; Barden, S. C.

1985-01-01

Spectra in the H-alpha and H-beta regions of the peculiar double-lined RS CVn binary, RT Lacertae, were obtained in the fall of 1984. Limited International Ultraviolet Explorer (IUE) long wavelength low and high resolution spectra were obtained concurrently. The ground based spectra have shown an asymmetry with orbital phase in the H-alpha profile. The H-beta profiles were consistent with the same effect. One hemisphere showed excess emission and the other excess absorption, with a broad Gaussian emission component superposed upon the excess H-alpha line. An improved radial velocity curve, giving a better determined mass ratio and geometry was derived. This combined with the radii implied by the rotational broadening of the spectra, showed one component to be 80 to 90% filling the equilibrium Roche surface. The two-faced nature is, therfore, very likely due to mass transfer from the contact component impacting upon its companion. Low resolution ultraviolet data showed that the supposed cooler component is bluer than its companion. High resolution ultraviolet data taken during secondary eclipse showed Mg II emission strength which decreased more slowly than the area visible. The phase behavior of the low resolution data support the former situation, indicating traditional chromospheric activity.

Optical and UV spectroscopy of the peculiar RS CVn system, RT Lacertae

NASA Astrophysics Data System (ADS)

Huenemoerder, D. P.; Barden, S. C.

1985-11-01

Spectra in the H-alpha and H-beta regions of the peculiar double-lined RS CVn binary, RT Lacertae, were obtained in the fall of 1984. Limited International Ultraviolet Explorer (IUE) long wavelength low and high resolution spectra were obtained concurrently. The ground based spectra have shown an asymmetry with orbital phase in the H-alpha profile. The H-beta profiles were consistent with the same effect. One hemisphere showed excess emission and the other excess absorption, with a broad Gaussian emission component superposed upon the excess H-alpha line. An improved radial velocity curve, giving a better determined mass ratio and geometry was derived. This combined with the radii implied by the rotational broadening of the spectra, showed one component to be 80 to 90% filling the equilibrium Roche surface. The two-faced nature is, therfore, very likely due to mass transfer from the contact component impacting upon its companion. Low resolution ultraviolet data showed that the supposed cooler component is bluer than its companion. High resolution ultraviolet data taken during secondary eclipse showed Mg II emission strength which decreased more slowly than the area visible. The phase behavior of the low resolution data support the former situation, indicating traditional chromospheric activity.

SMILES/AOS: acousto-optical spectrometer for high resolution submillimeter-wave spectroscopy

NASA Astrophysics Data System (ADS)

Mazuray, L.; Barthès, J.-C.; Bayle, F.; Castel, D.; Claviere, P.; Delbru, F.; Doittau, P.-O.; Gladin, L.; Guilleux, P.; Halbout, S.; Lavielle, D.; Varin, J.-L.; de Zotti, S.; Rosolen, C.; Ozeki, H.

2017-11-01

An acousto-optical spectrometer (AOS) is employed in order to meet scientific mission objectives of submillimeter-wave limb-emission sounder (SMILES) to be aboard the Japanese Experiment Module (JEM) of International space station (ISS). AOS is developed by ASTRIUM for the Japanese space agency (NASDA). The capability of multi channel detection with AOS is suitable for observing multi-chemical species in a wide frequency region. Low noise of the AOS enables us to obtain the spectra with a very high sensitivity. Several technical concerns relating to important instrumental characteristics of AOS are discussed and expected performance of the design are overviewed.

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.

Radio morphology and parent population of X-ray selected BL Lacertae objects

NASA Technical Reports Server (NTRS)

Laurent-Muehleisen, S. A.; Kollgaard, R. I.; Moellenbrock, G. A.; Feigelson, E. D.

1993-01-01

High-dynamic range (typically 1700:1) radio maps of 15 X-ray BL Lac (XBL) objects from the HEAO-1 Large Area Sky Survey are presented. Morphological characteristics of these sources are compared with Fanaroff-Riley (FR) class I radio galaxies in the context of unified schemes, with reference to one-sided kiloparsec-scale emission. Evidence that cluster membership of XBLs is significantly higher than previously thought is also presented. It is shown that the extended radio powers, X-ray emission, core-to-lobe ratios, and linear sizes of the radio selected BL Lac (RBL) and XBL populations are consistent with an FR I radio galaxy parent population. A source list and VLA observing log and map parameters are provided.

Promiscuity in sand lizards (Lacerta agilis) and adder snakes (Vipera berus): causes and consequences.

PubMed

Olsson, M; Madsen, T

2001-01-01

We review postcopulatory phenomena in the Swedish sand lizard (Lacerta agilis) and adder (Vipera berus), and in particular, links between female promiscuity, determinants of paternity, and offspring viability. In both species, females mate multiply and exhibit a positive relationship between the number of partners and offspring viability. We conclude that this relationship is most likely the result of variable genetic compatibility between mates arising from postcopulatory phenomena, predominantly assortative fertilization with respect to parental genotypes. However, males who were more successful at mate acquisition were also more successful in situations of sperm competition, suggesting a possible link between male (diploid and haploid) genetic quality per se and probability of fertilization. Neither the number of partners nor the number of matings influenced the risk of infertility in sand lizards, suggesting that selection for reduced risk of infertility is not a sufficient explanation for maintaining female promiscuity in this population. Finally, we conclude that the relatively low genetic variability exhibited by our study populations may have facilitated detection of genetic benefits compared to more outbred ones. However, recent work derived from outbred populations in other taxa suggest a greater generality of the principles we discuss than previously may have been appreciated.

Microchromosome polymorphism in the sand lizard, Lacerta agilis Linnaeus, 1758 (Reptilia, Squamata)

PubMed Central

Lisachov, Artem P.; Borodin, Pavel M.

2016-01-01

Abstract Most true lizards (Lacertidae) share a conservative karyotype, consisting of 18 pairs of macrochromosomes and one microchromosome pair. Homeologues of the microchromosome are present in other squamates and even in chickens. No structural autosomal microchromosome polymorphisms have been described previously in lizards. We found homozygous and heterozygous carriers of a microchromosome variant in a Siberian population of the sand lizard, Lacerta agilis Linnaeus, 1758. The variant microchromosome was almost twice as long as the standard one. In heterozygotes at pachytene, the microchromosomes firstly pair in proximal regions and the central part of the longer axial element undergoes foldback synapsis, then its distal region pairs with the distal region of the standard partner. At metaphase-I, the heteromorphic microchromosome bivalents have a proximal chiasma. The content of the additional segment was Ag-NOR, C-like DAPI, CMA3 negative. FISH with telomere PNA probe did not detect interstitial (TTAGGG)n sequences in the heteromorphic and any other bivalents. Both homo- and heterozygous carriers were phenotypically normal. The presence of homozygotes shows that heterozygotes are fertile. Reduction in the number of microchromosomes is a clear trend in squamate evolution, as a result of microchromosomes fusing together or with macrochromosomes. Our findings indicate that gaining additional DNA may lead to a transformation of microchromosomes into small macrochromosomes without fusion. PMID:27830048

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.

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.

Very high energy observations of the BL Lac objects 3C 66A and OJ 287

NASA Astrophysics Data System (ADS)

Lindner, T.; Hanna, D. S.; Kildea, J.; Ball, J.; Bramel, D. A.; Carson, J.; Covault, C. E.; Driscoll, D.; Fortin, P.; Gingrich, D. M.; Jarvis, A.; Mueller, C.; Mukherjee, R.; Ong, R. A.; Ragan, K.; Scalzo, R. A.; Williams, D. A.; Zweerink, J.

2007-11-01

Using the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE), we have observed the BL Lac objects 3C 66A and OJ 287. These are members of the class of low-frequency-peaked BL Lac objects (LBLs) and are two of the three LBLs predicted by Costamante and Ghisellini [L. Costamante, G. Ghisellini, Astron. Astrophys. 384 (2002) 56] to be potential sources of very high energy (>100 GeV) gamma-ray emission. The third candidate, BL Lacertae, has recently been detected by the MAGIC collaboration [J. Albert et al., arXiv:astro-ph/0703084v1 (2007)]. Our observations have not produced detections; we calculate a 99% CL upper limit of flux from 3C 66A of 0.15 Crab flux units and from OJ 287 our limit is 0.52 Crab. These limits assume a Crab-like energy spectrum with an effective energy threshold of 185 GeV.

European green lizard (Lacerta viridis) personalities: Linking behavioural types to ecologically relevant traits at different ontogenetic stages.

PubMed

Bajer, Katalin; Horváth, Gergely; Molnár, Orsolya; Török, János; Garamszegi, László Zsolt; Herczeg, Gábor

2015-02-01

Consistent individual differences within (animal personality) and across (behavioural syndrome) behaviours became well recognized during the past decade. Nevertheless, our knowledge about the evolutionary and developmental mechanisms behind the phenomena is still incomplete. Here, we explored if risk-taking and exploration were consistent and linked to different ecologically relevant traits in wild-caught adult male European green lizards (Lacerta viridis) and in their 2-3 weeks old laboratory-reared offspring. Both adults and juveniles displayed animal personality, consistency being higher in juveniles. We found correlation between risk-taking and exploration (suggestive of a behavioural syndrome) only in adults. Juveniles were more explorative than adults. Large or ectoparasite-free adult males were more explorative than small or parasitized males. Juvenile females tended to be more risk-taking than males. Behaviour of fathers and their offspring did not correlate. We conclude that European green lizards show high behavioural consistency and age is an important determinant of its strength and links to traits likely affecting fitness. Copyright © 2014 Elsevier B.V. All rights reserved.

Sand lizard (Lacerta agilis) phenology in a warming world.

PubMed

Ljungström, Gabriella; Wapstra, Erik; Olsson, Mats

2015-10-08

Present-day climate change has altered the phenology (the timing of periodic life cycle events) of many plant and animal populations worldwide. Some of these changes have been adaptive, leading to an increase in population fitness, whereas others have been associated with fitness decline. Representing short-term responses to an altered weather regime, hitherto observed changes are largely explained by phenotypic plasticity. However, to track climatically induced shifts in optimal phenotype as climate change proceeds, evolutionary capacity in key limiting climate- and fitness-related traits is likely to be crucial. In order to produce realistic predictions about the effects of climate change on species and populations, a main target for conservation biologists is thus to assess the potential of natural populations to respond by these two mechanisms. In this study we use a large 15-year dataset on an ectotherm model, the Swedish sand lizard (Lacerta agilis), to investigate how higher spring temperature is likely to affect oviposition timing in a high latitude population, a trait strongly linked to offspring fitness and survival. With an interest in both the short- and potential long-term effect of rising temperatures, we applied a random regression model, which yields estimates of population-level plasticity and among-individual variation in the average, as well as the plastic, response to temperature. Population plasticity represents capacity for short-term adjustments whereas variation among individuals in a fitness-related trait indicates an opportunity for natural selection and hence for evolutionary adaptation. The analysis revealed both population-level plasticity and individual-level variation in average laying date. In contrast, we found no evidence for variation among females in their plastic responses to spring temperature, which could demonstrate a similarity in responses amongst females, but may also be due to a lack of statistical power to detect such an

The complete mitochondrial genome of the green lizard Lacerta viridis viridis (Reptilia: Lacertidae) and its phylogenetic position within squamate reptiles.

PubMed

Böhme, M U; Fritzsch, G; Tippmann, A; Schlegel, M; Berendonk, T U

2007-06-01

For the first time the complete mitochondrial genome was sequenced for a member of Lacertidae. Lacerta viridis viridis was sequenced in order to compare the phylogenetic relationships of this family to other reptilian lineages. Using the long-polymerase chain reaction (long PCR) we characterized a mitochondrial genome, 17,156 bp long showing a typical vertebrate pattern with 13 protein coding genes, 22 transfer RNAs (tRNA), two ribosomal RNAs (rRNA) and one major noncoding region. The noncoding region of L. v. viridis was characterized by a conspicuous 35 bp tandem repeat at its 5' terminus. A phylogenetic study including all currently available squamate mitochondrial sequences demonstrates the position of Lacertidae within a monophyletic squamate group. We obtained a narrow relationship of Lacertidae to Scincidae, Iguanidae, Varanidae, Anguidae, and Cordylidae. Although, the internal relationships within this group yielded only a weak resolution and low bootstrap support, the revealed relationships were more congruent with morphological studies than with recent molecular analyses.

CATALOG AND STATISTICAL STUDY OF X-RAY SELECTED BL LACERTAE OBJECTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kapanadze, Bidzina Z., E-mail: bidzina_kapandaze@iliauni.edu.ge

2013-02-01

This paper presents a catalog of 312 X-ray selected BL Lacerate objects (XBLs), optically identified through the end of 2011. It contains the names from different surveys, equatorial coordinates, redshifts, multifrequency flux values, and luminosities for each source. In addition, the different characteristics of XBLs are statistically investigated (redshift, radio/optical/X-ray luminosities, central black hole (BH) mass, synchrotron peak frequency, broadband spectral indices, optical flux variability). Their values are collected through an extensive bibliographic and database search or calculated by us. The redshifts range from 0.031 to 0.702 with a maximum of the distribution at z = 0.223. The 1.4 GHzmore » luminosities of XBLs log {nu}L{sub {nu}} {approx} 39-42 erg s{sup -1} while optical V and X-ray 0.1-2.4 keV bands show log {nu}L{sub {nu}} {approx} 43-46 erg s{sup -1}. The XBL hosts are elliptical galaxies with effective radii r{sub eff} = 3.2625.40 kpc and ellipticities, in = 0.040.52. Their R-band absolute magnitudes M{sub R} range from -21.11 mag to -24.86 mag with a mean value of -22.83 mag. The V - R indices of the hosts span from 0.61 to 1.52 and reveal a fourth-degree polynomial relationship with z that enables us to evaluate the redshifts of five sources whose V - R indices were determined from the observations but whose irredshifts values are either not found or not confirmed. The XBL nuclei show a wider range of 7.31 mag for M{sub R} with the highest luminosity corresponding to M{sub R} = -27.24 mag. The masses of central BHs are found in the interval log M{sub BH} = 7.39-9.30 solar masses (with distribution maximum at log M{sub BH}/M{sub Sun} = 8.30). The synchrotron peak frequencies are spread over the range log {nu}{sub peak} = 14.56-19.18 Hz with a peak of the distribution at log {nu}{sub peak} = 16.60 Hz. The broadband radio-to-optical ({alpha}{sub ro}), optical-to-X-ray ({alpha}{sub ox}), and radio-to-X-ray ({alpha}{sub rx}) spectral indices

Objective age of acquisition norms for a set of 286 words in Russian: relationships with other psycholinguistic variables.

PubMed

Grigoriev, Andrei; Oshhepkov, Ivan

2013-12-01

Normative data on the objective age of acquisition (AoA) for 286 Russian words are presented in this article. In addition, correlations between the objective AoA and subjective ratings, name agreement, picture name agreement, imageability, familiarity, word frequency, and word length are provided, as are correlations between the objective AoA and two measures of exemplar dominance (exemplar generation frequency and the number of times an exemplar was named first). The correlations between the aforementioned variables are generally consistent with the correlations reported in other normative studies. The objective AoA data are highly correlated with the subjective AoA ratings, whereas the correlations between the objective AoA and other psycholinguistic variables are moderate. The correlations between the objective AoA of Russian words and similar data for other languages are moderately high. The complete word norms may be downloaded from supplementary material.

Maintenance of the catalog of artificial objects in space.

NASA Astrophysics Data System (ADS)

Khutorovskij, Z. N.

1994-01-01

The catalog of artificial objects in space (AOS) is useful for estimating the safety of space flights, for constructing temporal and spatial models of the flux of AOS, for determining when and where dangerous AOS will break up, for tracking inoperative instruments and space stations, for eliminating false alarms that are triggered by observations of AOS in the Ballistic Missile Early Warning System and in the Anti-Missile system, etc. At present, the Space Surveillance System (located in the former USSR) automatically maintains a catalog consisting of more than 5000 AOS with dimensions of at least 10 cm. The orbital parameters are continuously updated from radar tracking data. The author describes the software which is used to process the information. He presents some of the features of the system itself, including the number of objects in various stages of the tracking process, the orbital parameters of AOS which break up, and how the fragments are detected, the accuracy of tracking and predicting the orbits of the AOS, and the accuracy with which we can estimate when and where an AOS will break up. As an example, the author presents the results of determination of the time when the orbiting complex Salyut-7 - Kosmos-1686 will break up, and where it will impact.

Modulation of the relationship between spring AO and the subsequent winter ENSO by the preceding November AO.

PubMed

Chen, Shangfeng; Chen, Wen; Yu, Bin

2018-05-02

Previous studies indicated that the spring Arctic Oscillation (AO) exerts significant influences on the subsequent winter El Niño-Southern Oscillation (ENSO). This analysis suggests that the spring AO-ENSO linkage is highly modulated by its preceding November AO. When November and the subsequent spring AO indices are in phase, the spring AO has a pronounced influence on ENSO. However, when the November and spring AO indices are out of phase, the spring AO-ENSO connection disappears. Modulation of the November AO on the spring AO-ENSO connection is mainly through the constructive and destructive superposition of the November and spring AO associated sea surface temperature (SST) anomalies in the tropical central-eastern Pacific in spring and summer, as well as the SST anomalies developed further in the tropical Pacific via the positive air-sea feedback.

Hα spectroscopy and BV photometry of RT Lacertae

NASA Astrophysics Data System (ADS)

Frasca, A.; Çakırlı, Ö.; Catalano, S.; Ibanoǧlu, C.; Marilli, E.; Evren, S.; Taş, G.

2002-06-01

Contemporaneous spectroscopic and photometric B V observations of the RS CVn type eclipsing binary RT Lacertae were performed in summer 2000. The photometric observations were obtained at the Ege University Observatory, while the spectroscopic ones were carried out at Catania Astrophysical Observatory in the spectral range 5860-6700 Å. We obtained a high quality radial velocity curve of the system that allowed us to give more accurate values of the orbital parameters. A steady decrease of the barycentric velocity from 1920 to 2000 has been pointed out and has been discussed in the context of a third body hypothesis. Through the subtraction of a ``synthetic'' spectrum, built up with spectra of inactive standard stars, we detected Hα excess emission which fills in the photospheric absorption profiles of both components. With the exception of a few spectra, taken close to the eclipses, in which some extra absorption or a faint double-peaked broad emission appears, there is no further evidence of circumstellar matter in this system, as suggested in previous works. The hotter and more massive star appears also as the more active at a chromospheric level, since it has a Hα flux about ten times greater than the companion, on average. Rotational modulation of the Hα emission has been detected in both stars. The hemisphere of the more massive star facing the observer at phase 0fp75 appears brighter (in Hα ) than that seen at phase 0fp25 , while for the less massive G9 IV star the maximum Hα emission is seen around phase 0fp0-0fp1 . From the analysis of the contemporaneous light curve (Lanza et al. \\cite{Lanza2001}), the more massive G5 IV star results to be more active than the companion at a photospheric level, in agreement with the chromospheric behaviour observed in Hα . In addition, the starspots of the G5 IV star are mainly located in the Hα brighter hemisphere, suggesting a close spatial association of spots and plages in this star. The G9 IV star displays

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 (�

MagAO: status and science

NASA Astrophysics Data System (ADS)

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

2016-07-01

"MagAO" is the adaptive optics instrument at the Magellan Clay telescope at Las Campanas Observatory, Chile. MagAO has a 585-actuator adaptive secondary mirror and 1000-Hz pyramid wavefront sensor, operating on natural guide stars from R-magnitudes of -1 to 15. MagAO has been in on-sky operation for 166 nights since installation in 2012. MagAO's unique capabilities are simultaneous imaging in the visible and infrared with VisAO and Clio, excellent performance at an excellent site, and a lean operations model. Science results from MagAO include the first ground-based CCD image of an exoplanet, demonstration of the first accreting protoplanets, discovery of a new wide-orbit exoplanet, and the first empirical bolometric luminosity of an exoplanet. We describe the status, report the AO performance, and summarize the science results. New developments reported here include color corrections on red guide stars for the wavefront sensor; a new field stop stage to facilitate VisAO imaging of extended sources; and eyepiece observing at the visible-light diffraction limit of a 6.5-m telescope. We also discuss a recent hose failure that led to a glycol coolant leak, and the recovery of the adaptive secondary mirror (ASM) after this recent (Feb. 2016) incident.

Coordinated observations of X-ray bright BL Lacertae objects

NASA Technical Reports Server (NTRS)

Urry, C. M.

1986-01-01

No new International Ultraviolet Explorer (IUE) observations were scheduled. The work on the spectral extraction routine was continued. The computer code was adapted from the RDAF PDP 11/44 computer to a VAX 11/750, in order that it run more quickly. A chapter on ultraviolet observations of blazars for a book celebrating the scientific accomplishment of IUE was written in colloboration. A copy of the final draft is attached.

Robo-AO Kepler Asteroseismic Survey. I. Adaptive Optics Imaging of 99 Asteroseismic Kepler Dwarfs and Subgiants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schonhut-Stasik, Jessica S.; Baranec, Christoph; Huber, Daniel

We used the Robo-AO laser adaptive optics (AOs) system to image 99 main sequence and subgiant stars that have Kepler -detected asteroseismic signals. Robo-AO allows us to resolve blended secondary sources at separations as close as ∼0.″15 that may contribute to the measured Kepler light curves and affect asteroseismic analysis and interpretation. We report eight new secondary sources within 4.″0 of these Kepler asteroseismic stars. We used Subaru and Keck AOs to measure differential infrared photometry for these candidate companion systems. Two of the secondary sources are likely foreground objects, while the remaining six are background sources; however, we cannotmore » exclude the possibility that three of the objects may be physically associated. We measured a range of i ′-band amplitude dilutions for the candidate companion systems from 0.43% to 15.4%. We find that the measured amplitude dilutions are insufficient to explain the previously identified excess scatter in the relationship between asteroseismic oscillation amplitude and the frequency of maximum power.« less

The X-ray spectra of the BL Lacertae objects PKS 0548 - 322 and 3C 66A

NASA Technical Reports Server (NTRS)

Maccacaro, T.; Maccagni, D.; Tarenghi, M.

1983-01-01

Einstein Observatory simultaneous imaging proportional counter and monitor proportional counter data are combined in order to derive the energy spectra of the BL Lac objects PKS 0548-322 and 3C 66A between 0.2 and 10 keV. While the latter is found to be variable in both intensity and spectral shape, the former, although constant in the present data, is found to have experienced a spectrum variation in view of results from other experiments. Attention is given to the implications of flux and spectral variability in BL Lac objects for models of X-ray emission mechanisms. It is suggested that the wide spread of the spectral index distribution is due to the detection of the highly variable synchrotron-produced X-rays that are generally undetected in QSOs.

Lack of congruence between morphometric evolution and genetic differentiation suggests a recent dispersal and local habitat adaptation of the Madeiran lizard Lacerta dugesii

PubMed Central

Brehm, António; Khadem, Mahnaz; Jesus, José; Andrade, Paula; Vicente, Luis

2001-01-01

Genetic differentiation among nine populations of the endemic lizard Lacerta dugesii Milne-Edwards 1829 (Lacertidae) from four groups of islands constituting the Archipelago of Madeira, was investigated by protein electrophoresis at 23 enzyme loci. Among twenty polymorphic loci, the total genetic diversity was due primarily to intra-population variation. The allele and genotypic frequencies among populations showed some heterogeneity, allowing the species to present a structuring pattern compatible with their geographical clustering. Some evidence suggests that selection acting on some loci in different ecological conditions may be responsible for the clustering of the populations studied. There was no apparent isolation effect expected under an "island" model of population divergence, and no correlation was found between genetic and geographic distances among populations. Morphological variation of the proposed three L. dugesii subspecies is not congruent with the allozyme analysis. This most probably suggests a rapid colonization of the islands followed by a strong effect of selection operating over the morphological characters used to define the subspecies. PMID:11742635

Environment-dependence of behavioural consistency in adult male European green lizards (Lacerta viridis).

PubMed

Horváth, Gergely; Mészáros, Boglárka; Urszán, Tamás János; Bajer, Katalin; Molnár, Orsolya; Garamszegi, László Zsolt; Herczeg, Gábor

2017-01-01

Understanding the background mechanisms affecting the emergence and maintenance of consistent between-individual variation within population in single (animal personality) or across multiple (behavioural syndrome) behaviours has key importance. State-dependence theory suggests that behaviour is 'anchored' to individual state (e.g. body condition, gender, age) and behavioural consistency emerges through behavioural-state feedbacks. A number of relevant state variables are labile (e.g. body condition, physiological performance) and expected to be affected by short-term environmental change. Yet, whether short-term environmental shifts affect behavioural consistency during adulthood remains questionable. Here, by employing a full-factorial laboratory experiment, we explored if quantity of food (low vs. high) and time available for thermoregulation (3h vs. 10h per day) had an effect on activity and risk-taking of reproductive adult male European green lizards (Lacerta viridis). We focussed on different components of behavioural variation: (i) strength of behavioural consistency (repeatability for animal personality; between-individual correlation for behavioural syndrome), (ii) behavioural type (individual mean behaviour) and (iii) behavioural predictability (within-individual behavioural variation). Activity was repeatable in all treatments. Risk-taking was repeatable only in the low basking treatments. We found significant between-individual correlation only in the low food × long basking time group. The treatments did not affect behavioural type, but affected behavioural predictability. Activity predictability was higher in the short basking treatment, where it also decreased with size (≈ age). Risk-taking predictability in the short basking treatment increased with size under food limitation, but decreased when food supply was high. We conclude that short-term environmental change can alter various components of behavioural consistency. The effect could be

Environment-dependence of behavioural consistency in adult male European green lizards (Lacerta viridis)

PubMed Central

Urszán, Tamás János; Bajer, Katalin; Molnár, Orsolya; Garamszegi, László Zsolt; Herczeg, Gábor

2017-01-01

Understanding the background mechanisms affecting the emergence and maintenance of consistent between-individual variation within population in single (animal personality) or across multiple (behavioural syndrome) behaviours has key importance. State-dependence theory suggests that behaviour is ‘anchored’ to individual state (e.g. body condition, gender, age) and behavioural consistency emerges through behavioural-state feedbacks. A number of relevant state variables are labile (e.g. body condition, physiological performance) and expected to be affected by short-term environmental change. Yet, whether short-term environmental shifts affect behavioural consistency during adulthood remains questionable. Here, by employing a full-factorial laboratory experiment, we explored if quantity of food (low vs. high) and time available for thermoregulation (3h vs. 10h per day) had an effect on activity and risk-taking of reproductive adult male European green lizards (Lacerta viridis). We focussed on different components of behavioural variation: (i) strength of behavioural consistency (repeatability for animal personality; between-individual correlation for behavioural syndrome), (ii) behavioural type (individual mean behaviour) and (iii) behavioural predictability (within-individual behavioural variation). Activity was repeatable in all treatments. Risk-taking was repeatable only in the low basking treatments. We found significant between-individual correlation only in the low food × long basking time group. The treatments did not affect behavioural type, but affected behavioural predictability. Activity predictability was higher in the short basking treatment, where it also decreased with size (≈ age). Risk-taking predictability in the short basking treatment increased with size under food limitation, but decreased when food supply was high. We conclude that short-term environmental change can alter various components of behavioural consistency. The effect could be

Sakurai's Object Continues to Brighten and Expand

NASA Astrophysics Data System (ADS)

Hinkle, Kenneth H.; Joyce, Richard R.; Matheson, Thomas

2017-01-01

Sakurai's Object (V4334 Sgr), the prototype final flash object discovered in the mid-1990s, was observed to undergo rapid cooling becoming as faint as 25th magnitude at K during the first decade of the 21st century. A review of imaging data suggests the minimum K magnitude occurred about 2006. Sakuarai's Object was re-acquired at K in 2010. Between 2010 Sep and 2013 Apr Sakurai's object brightened more than 2 magnitudes to K=14.2. Here we report on a Gemini-NIRI K band AO image obtained in 2016 July. The Ks magnitude was 13.35. The AO image also records the continuing expansion of the debris cloud. The central star remains obscured. Spectro-spatial NIFS images of the spectral region around He I 1.0830 micron and a GMOS optical spectrum, both observed in 2015, will also be displayed.

The Millimeter-Radio Emission of BL Lacertae During Two γ-ray Outbursts

NASA Astrophysics Data System (ADS)

Kim, Dae-Won; Trippe, Sascha; Lee, Sang-Sung; Park, Jong-Ho; Kim, Jae-Young; Algaba, Juan-Carlos; Hodgson, Jeffrey A.; Kino, Motoki; Zhao, Guang-Yao; Wajima, Kiyoaki; Kang, Sincheol; Oh, Junghwan; Lee, Taeseok; Byun, Do-Young; Kim, Soon-Wook; Kim, Jeong-Sook

2017-12-01

We present a study of the inexplicit connection between radio jet activity and γ-ray emission of BL Lacertae (BL Lac; 2200+420). We analyze the long-term millimeter activity of BL Lac via interferometric observations with the Korean VLBI Network (KVN) obtained at 22, 43, 86, and 129 GHz simultaneously over three years (from January 2013 to March 2016); during this time, two γ-ray outbursts (in November 2013 and March 2015) can be seen in γ-ray light curves obtained from Fermi observations. The KVN radio core is optically thick at least up to 86 GHz; there is indication that it might be optically thin at higher frequencies. To first order, the radio light curves decay exponentially over the time span covered by our observations, with decay timescales of 411±85 days, 352±79 days, 310±57 days, and 283±55 days at 22, 43, 86, and 129 GHz, respectively. Assuming synchrotron cooling, a cooling time of around one year is consistent with magnetic field strengths B=2 μT and electron Lorentz factors γ=10,000. Taking into account that our formal measurement errors include intrinsic variability and thus over-estimate the statistical uncertainties, we find that the decay timescale τ scales with frequency ν like τ∝ν^{-0.2}. This relation is much shallower than the one expected from opacity effects (core shift), but in agreement with the (sub-)mm radio core being a standing recollimation shock. We do not find convincing radio flux counterparts to the γ-ray outbursts. The spectral evolution is consistent with the 'generalized shock model' of Valtaoja et al. (1992). A temporary increase in the core opacity and the emergence of a knot around the time of the second γ-ray event indicate that this γ-ray outburst might be an 'orphan' flare powered by the 'ring of fire' mechanism.

Quasi-simultaneous observations of the BL Lac object MK 501 in X-ray, UV, visible, IR and radio frequencies

NASA Technical Reports Server (NTRS)

Kondo, D. M.; Worrall, D. M.; Mushotzky, R. F.; Hackney, R. L.; Hackney, K. H.; Oke, J. B.; Yee, H.; Neugebauer, G.; Matthews, K.; Feldman, P. A.

1980-01-01

Quasi-simultaneous observations of the BL Lacertae (Lac) objects MK 501 were performed for the first time at X-ray, ultraviolet, visible, infrared, and radio frequencies. The observed spectral slope from the X-ray to UV regions is positive and continuous, but that from the mid UV to visible light region becomes gradually flat and possibly turns down toward lower frequencies; the optical radio emission can not be accounted for by a single power law. Several theoretical models were considered for the emission mechanism. A quantitative comparison was performed with the synchrotron-self-Compton model; the total spectrum is found consistent with this model. The spectrum from visible light to X-ray is consistent with synchrotron radiation or with inverse-Compton scattering by a hot thermal cloud of electrons. The continuity of the spectral slope from X-ray to UV implied by the current data suggests that the previous estimates of the total luminosity of this BL Lac object is underestimated by a factor of about three or four.

PKS 2155-304 relativistically beamed synchrotron radiation from BL LAC object

NASA Technical Reports Server (NTRS)

Urry, C. M.; Mushotzky, R. F.

1981-01-01

The newly discovered BL Lacertae object, PKS 2155-304, was observed with the medium and high intensity energy detectors of the HEAO-1 A2 experiment. The variability by a factor of two in less than a day reported by Snyder, et al (1979) is confirmed. Two spectra, obtained a year apart, while the satellite was in scanning mode, are well fit by simple power laws with energy spectral index alpha sub 1 equals approximately 1.4. A third spectrum, of higher statistical quality, obtained while the satellite was pointed at its source, has has two components. An acceptable fit was obtained using a two power law model, with indices alpha sub 1 equals 2.0 (+1.2, -0.6) and alpha sub 2 equals -1.5 (+1.5, -2.3). An interpretation of the overall spectrum from radio through X-rays in terms of a synchrotron self-Compton model gives a good description of the data if allowance is made for relativistic beaming. Thus, from a consideration of the spectrum, combined with an estimate of the size of the source, the presence of jets is inferred without their observation.

THE OPTICAL MICROVARIABILITY AND SPECTRAL CHANGES OF THE BL LACERTAE OBJECT S5 0716+714

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poon, H.; Fu, J. N.; Fan, J. H.

We monitored the BL Lac object S5 0716+714 in the optical band during 2008 October and December and 2009 February with a best temporal resolution of about 5 minutes in the BVRI bands. Four fast flares were observed with amplitudes ranging from 0.3 to 0.75 mag. The source remained active during the whole monitoring campaign, showing microvariability in all days except for one. The overall variability amplitudes are {delta}B {approx} 0fm89, {delta}V {approx} 0fm80, {delta}R {approx} 0fm73, and {delta}I{approx} 0fm51. Typical timescales of microvariability range from 2 to 8 hr. The overall V - R color index ranges from 0.37more » to 0.59. Strong bluer-when-brighter chromatism was found on internight timescales. However, a different spectral behavior was found on intranight timescales. A possible time lag of {approx}11 minutes between B and I bands was found on one night. The shock-in-jet model and geometric effects can be applied to explain the source's intranight behavior.« less

Reactions of green lizards (Lacerta viridis) to major repellent compounds secreted by Graphosoma lineatum (Heteroptera: Pentatomidae).

PubMed

Gregorovičová, Martina; Černíková, Alena

2015-06-01

The chemical defence of Heteroptera is primarily based on repellent secretions which signal the potential toxicity of the bug to its predators. We tested the aversive reactions of green lizards (Lacerta viridis) towards the major compounds of the defensive secretion of Graphosoma lineatum, specifically: (i) a mixture of three aldehydes: (E)-hex-2-enal, (E)-oct-2-enal, (E)-dec-2-enal; (ii) a mixture of these three aldehydes and tridecane; (iii) oxoaldehyde: (E)-4-oxohex-2-enal; (iv) secretion extracted from metathoracic scent glands of G. lineatum adults and (v) hexane as a non-polar solvent. All chemicals were presented on a palatable food (Tenebrio molitor larvae). The aversive reactions of the green lizards towards the mealworms were evaluated by observing the approach latencies, attack latencies and approach-attack intervals. The green lizards exhibited a strong aversive reaction to the mixture of three aldehydes. Tridecane reduced the aversive reaction to the aldehyde mixture. Oxoaldehyde caused the weakest, but still significant, aversive reaction. The secretion from whole metathoracic scent glands also clearly had an aversive effect on the green lizards. Moreover, when a living specimen of G. lineatum or Pyrrhocoris apterus (another aposematic red-and-black prey) was presented to the green lizards before the trials with the aldehyde mixture, the aversive effect of the mixture was enhanced. In conclusion, the mixture of three aldehydes had the strong aversive effect and could signal the potential toxicity of G. lineatum to the green lizards. Copyright © 2015 Elsevier GmbH. All rights reserved.

Multifrequency observations of the BL Lacertae object PKS 0537 - 441

NASA Technical Reports Server (NTRS)

Maraschi, L.; Treves, A.; Schwartz, D. A.; Tanzi, E. G.

1985-01-01

PKS 0537 - 441 was repeatedly observed in the UV band with the International Ultraviolet Explorer and in the X-ray with the Einstein Observatory. On September 27, 1980, simultaneous observations in the two bands were obtained. Near-infrared photometry preceding and following the simultaneous observations by about one month is available from the literature, as is radio monitoring at 408 and 5000 MHz. Comparison of the observed X-ray flux with that predicted by the standard synchrotron self-Compton formalism, with a source dimension deduced from radio variability at 5 GHz, indicates that this component of the radio emission must be moving at relativistic speed with an effective projected Doppler beaming factor of about 10.

HESS J1943+213: A candidate extreme BL Lacertae object

DOE PAGES

Abramowski, A.; Acero, F.; Aharonian, F.; ...

2011-03-30

In this paper, we report on a newly detected point-like source, HESS J1943+213. This source coincides with an unidentified hard X-ray source IGR J19443+2117, which was proposed to have radio and infrared counterparts. Here, we combine new H.E.S.S., Fermi/LAT and Nançay Radio Telescope observations with pre-existing non-simultaneous multi-wavelength observations of IGR J19443+2117 and discuss the likely source associations as well as the interpretation as an active galactic nucleus, a gamma-ray binary or a pulsar wind nebula.

A Prediction of the Damping Properties of Hindered Phenol AO-60/polyacrylate Rubber (AO-60/ACM) Composites through Molecular Dynamics Simulation

NASA Astrophysics Data System (ADS)

Yang, Da-Wei; Zhao, Xiu-Ying; Zhang, Geng; Li, Qiang-Guo; Wu, Si-Zhu

2016-05-01

Molecule dynamics (MD) simulation, a molecular-level method, was applied to predict the damping properties of AO-60/polyacrylate rubber (AO-60/ACM) composites before experimental measures were performed. MD simulation results revealed that two types of hydrogen bond, namely, type A (AO-60) -OH•••O=C- (ACM), type B (AO-60) - OH•••O=C- (AO-60) were formed. Then, the AO-60/ACM composites were fabricated and tested to verify the accuracy of the MD simulation through dynamic mechanical thermal analysis (DMTA). DMTA results showed that the introduction of AO-60 could remarkably improve the damping properties of the composites, including the increase of glass transition temperature (Tg) alongside with the loss factor (tan δ), also indicating the AO-60/ACM(98/100) had the best damping performance amongst the composites which verified by the experimental.

LHEA contributions to the Future of Ultraviolet Astronomy Based on Six Years of IUE Research

NASA Technical Reports Server (NTRS)

Mushotzky, R. F.; Urry, C. M.

1984-01-01

Astronomical models of galactic nuclei emission spectra are reassessed in light of ultraviolet and X-ray spectroscopic observations. Spectral analysis of BL Lacertae objects using data collected by the International Ultraviolet Explorer (IUE) and other astronomical observatories is presented.

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. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Objective age of acquisition for 223 Italian words: norms and effects on picture naming speed.

PubMed

Lotto, Lorella; Surian, Luca; Job, Remo

2010-02-01

The present study provides a set of objective age of acquisition (AoA) norms for 223 Italian words that may be useful for conducting cross-linguistic studies or experiments on Italian language processing. The data were collected by presenting children from the ages of 2 to 11 with a normed picture set (Lotto, Dell'Acqua, & Job, 2001). Following the study of Morrison, Chappell, and Ellis (1997), we report two measures of objective AoA. Both measures strongly correlated with each other, and they also showed a good correlation with the rated AoA provided by adult participants. Furthermore, we assessed the relationship between the AoA measures and other variables used in psycholinguistic experiments. Regression analyses showed that familiarity, typicality, and word frequency were significant predictors of AoA. AoA, but not word frequency, was found to determine naming latencies. Finally, we present a path model in which AoA is a mediator in predicting speed in picture naming. The norms and the picture set can also be downloaded from http://dpss.psy.unipd.it/files/strumenti.php and from http://brm.psychonomic-journals.org/content/supplemental.

Ondas de choque em jatos de quasares e objetos BL Lacertae

NASA Astrophysics Data System (ADS)

Melo, F. E.; Botti, L. C. L.

2003-08-01

Este trabalho é parte de um projeto que vem sendo realizado há dois anos no CRAAM, cujos objetivos principais são analisar e aplicar um modelo generalizado de ondas de choque em jatos relativísticos de plasma, presentes em quasares e objetos BL Lacertae, para explicar a variabilidade observada nestes objetos. O método consiste em uma decomposição de curvas de luz em séries de explosões similares, em várias freqüências, baseando-se em uma evolução espectro-temporal média das explosões. A partir da evolução média, um ajuste de cada explosão é feito com base em equações empíricas, modificando-se apenas parâmetros específicos de cada explosão. Inicialmente o modelo foi aplicado ajustando-se as curvas de luz a explosões delineadas por uma evolução do choque em três estágios, segundo a predominância do processo de emissão: síncrotron, Compton e adiabático. Entretanto, nesta nova fase de projeto, visando uma parametrização mais concisa, uma otimização do algoritmo de ajuste e uma convergência mais rápida, a formulação para cada evento foi assumida com uma evolução em apenas dois estágios: subida e descida. Isto possibilitou uma ótima delineação das curvas de luz das fontes OV236, OJ287, 3C273 e BL Lac, entre 1980 e 2000, nas freqüências 4.8, 8.0, 14.5 e 22 GHz, utilizando-se dados do Observatório da Universidade de Michigan, do Observatório do Itapetinga (Atibaia SP) e do Observatório Metsähovi. Como conclusões importantes, verificou-se que: os parâmetros ajustados descrevem o comportamento do jato; os valores do índice que descreve a expansão do jato sugerem que o mesmo se expande de uma forma não-cônica; o campo magnético é turbulento atrás da frente de choque; e as peculiaridades das explosões são devidas à influência de grandezas tais como o coeficiente da distribuição espectral de energia dos elétrons, a intensidade de campo magnético e o fator de feixe Doppler, no início do choque.

AO Distal Radius Fracture Classification: Global Perspective on Observer Agreement.

PubMed

Jayakumar, Prakash; Teunis, Teun; Giménez, Beatriz Bravo; Verstreken, Frederik; Di Mascio, Livio; Jupiter, Jesse B

2017-02-01

Background  The primary objective of this study was to test interobserver reliability when classifying fractures by consensus by AO types and groups among a large international group of surgeons. Secondarily, we assessed the difference in inter- and intraobserver agreement of the AO classification in relation to geographical location, level of training, and subspecialty. Methods  A randomized set of radiographic and computed tomographic images from a consecutive series of 96 distal radius fractures (DRFs), treated between October 2010 and April 2013, was classified using an electronic web-based portal by an invited group of participants on two occasions. Results  Interobserver reliability was substantial when classifying AO type A fractures but fair and moderate for type B and C fractures, respectively. No difference was observed by location, except for an apparent difference between participants from India and Australia classifying type B fractures. No statistically significant associations were observed comparing interobserver agreement by level of training and no differences were shown comparing subspecialties. Intra-rater reproducibility was "substantial" for fracture types and "fair" for fracture groups with no difference accounting for location, training level, or specialty. Conclusion  Improved definition of reliability and reproducibility of this classification may be achieved using large international groups of raters, empowering decision making on which system to utilize. Level of Evidence  Level III.

AO Distal Radius Fracture Classification: Global Perspective on Observer Agreement

PubMed Central

Jayakumar, Prakash; Teunis, Teun; Giménez, Beatriz Bravo; Verstreken, Frederik; Di Mascio, Livio; Jupiter, Jesse B.

2016-01-01

Background The primary objective of this study was to test interobserver reliability when classifying fractures by consensus by AO types and groups among a large international group of surgeons. Secondarily, we assessed the difference in inter- and intraobserver agreement of the AO classification in relation to geographical location, level of training, and subspecialty. Methods A randomized set of radiographic and computed tomographic images from a consecutive series of 96 distal radius fractures (DRFs), treated between October 2010 and April 2013, was classified using an electronic web-based portal by an invited group of participants on two occasions. Results Interobserver reliability was substantial when classifying AO type A fractures but fair and moderate for type B and C fractures, respectively. No difference was observed by location, except for an apparent difference between participants from India and Australia classifying type B fractures. No statistically significant associations were observed comparing interobserver agreement by level of training and no differences were shown comparing subspecialties. Intra-rater reproducibility was “substantial” for fracture types and “fair” for fracture groups with no difference accounting for location, training level, or specialty. Conclusion Improved definition of reliability and reproducibility of this classification may be achieved using large international groups of raters, empowering decision making on which system to utilize. Level of Evidence Level III PMID:28119795

Interactions between visual and semantic processing during object recognition revealed by modulatory effects of age of acquisition.

PubMed

Urooj, Uzma; Cornelissen, Piers L; Simpson, Michael I G; Wheat, Katherine L; Woods, Will; Barca, Laura; Ellis, Andrew W

2014-02-15

The age of acquisition (AoA) of objects and their names is a powerful determinant of processing speed in adulthood, with early-acquired objects being recognized and named faster than late-acquired objects. Previous research using fMRI (Ellis et al., 2006. Traces of vocabulary acquisition in the brain: evidence from covert object naming. NeuroImage 33, 958-968) found that AoA modulated the strength of BOLD responses in both occipital and left anterior temporal cortex during object naming. We used magnetoencephalography (MEG) to explore in more detail the nature of the influence of AoA on activity in those two regions. Covert object naming recruited a network within the left hemisphere that is familiar from previous research, including visual, left occipito-temporal, anterior temporal and inferior frontal regions. Region of interest (ROI) analyses found that occipital cortex generated a rapid evoked response (~75-200 ms at 0-40 Hz) that peaked at 95 ms but was not modulated by AoA. That response was followed by a complex of later occipital responses that extended from ~300 to 850 ms and were stronger to early- than late-acquired items from ~325 to 675 ms at 10-20 Hz in the induced rather than the evoked component. Left anterior temporal cortex showed an evoked response that occurred significantly later than the first occipital response (~100-400 ms at 0-10 Hz with a peak at 191 ms) and was stronger to early- than late-acquired items from ~100 to 300 ms at 2-12 Hz. A later anterior temporal response from ~550 to 1050 ms at 5-20 Hz was not modulated by AoA. The results indicate that the initial analysis of object forms in visual cortex is not influenced by AoA. A fastforward sweep of activation from occipital and left anterior temporal cortex then results in stronger activation of semantic representations for early- than late-acquired objects. Top-down re-activation of occipital cortex by semantic representations is then greater for early than late acquired objects

PHOTOMETRIC PROPERTIES FOR SELECTED ALGOL-TYPE BINARIES. II. AO SERPENTIS AND V338 HERCULIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Y.-G.; Dai, H.-F.; Hu, S.-M.

2010-04-15

We present the first multiband photometry for the semidetached eclipsing binary AO Serpentis, observed on seven nights between 2009 April and July at the Weihai Observatory of Shandong University. By using the 2003 version of the Wilson-Devinney code, the photometric solutions of AO Ser and a similar object V338 Her were (re)deduced. The spectral types and orbital periods are A2 and P = 0.8793 days for AO Ser, F1V and P = 1.3057 days for V338 Her. The results reveal that two binaries are low mass ratio systems, whose secondary components fill their Roche lobes. The fill-out factors of themore » primary components are f = 58.6% for AO Ser and f = 54.2% for V338 Her, respectively. From the O - C curves of AO Ser and V338 Her, it is discovered that secular period changes with cyclic variations exist. The periods and semiamplitudes are 17.32({+-}0.01) yr and 0.0051({+-}0.0001) days for AO Ser, 29.07({+-}0.04) yr and 0.0116({+-}0.0015) days for V338 Her, respectively. This kind of cyclic oscillation may be attributed to either the light-time effect via an assumed third body or perhaps cyclic magnetic activity on the secondary component. For AO Ser, the long-term period decreases at a rate of dP/dt = -5.35({+-}0.03) x 10{sup -7} days yr{sup -1}, which may be caused by mass and angular momentum loss from the system. Considering the period decreasing, the fill-out factor of the primary for AO Ser will increase and it will finally fill its Roche lobe. Meanwhile, the secular period increase rate for V338 Her is dP/dt = +1.44({+-}0.24) x 10{sup -7} days yr{sup -1}, indicating that mass transfers from the less massive component to the more massive component. This will also cause the fill-out factor of the primary to increase. When the primaries fill their Roche lobes, AO Ser and V338 Her may evolve into contact stars, as predicted by the theory of thermal relaxation oscillations.« less

Geographic variation of life-history traits in the sand lizard, Lacerta agilis: testing Darwin's fecundity-advantage hypothesis.

PubMed

Roitberg, E S; Eplanova, G V; Kotenko, T I; Amat, F; Carretero, M A; Kuranova, V N; Bulakhova, N A; Zinenko, O I; Yakovlev, V A

2015-03-01

The fecundity-advantage hypothesis (FAH) explains larger female size relative to male size as a correlated response to fecundity selection. We explored FAH by investigating geographic variation in female reproductive output and its relation to sexual size dimorphism (SSD) in Lacerta agilis, an oviparous lizard occupying a major part of temperate Eurasia. We analysed how sex-specific body size and SSD are associated with two putative indicators of fecundity selection intensity (clutch size and the slope of the clutch size-female size relationship) and with two climatic variables throughout the species range and across two widespread evolutionary lineages. Variation within the lineages provides no support for FAH. In contrast, the divergence between the lineages is in line with FAH: the lineage with consistently female-biased SSD (L. a. agilis) exhibits higher clutch size and steeper fecundity slope than the lineage with an inconsistent and variable SSD (L. a. exigua). L. a. agilis shows lower offspring size (egg mass, hatchling mass) and higher clutch mass relative to female mass than L. a. exigua, that is both possible ways to enhance offspring number are exerted. As the SSD difference is due to male size (smaller males in L. a. agilis), fecundity selection favouring larger females, together with viability selection for smaller size in both sexes, would explain the female-biased SSD and reproductive characteristics of L. a. agilis. The pattern of intraspecific life-history divergence in L. agilis is strikingly similar to that between oviparous and viviparous populations of a related species Zootoca vivipara. Evolutionary implications of this parallelism are discussed. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

The first Fermi multifrequency campaign on BL Lacertae: Characterizing the low-activity state of the eponymous blazar

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2011-03-10

Here, we report on observations of BL Lacertae during the first 18 months of Fermi LAT science operations and present results from a 48 day multifrequency coordinated campaign from 2008 August 19 to 2008 October 7. The radio to gamma-ray behavior of BL Lac is unveiled during a low-activity state thanks to the coordinated observations of radio-band (Metsähovi and VLBA), near-IR/optical (Tuorla, Steward, OAGH, and MDM), and X-ray ( RXTE and Swift) observatories. No variability was resolved in gamma rays during the campaign, and the brightness level was 15 times lower than the level of the 1997 EGRET outburst. Moderatemore » and uncorrelated variability has been detected in UV and X-rays. The X-ray spectrum is found to be concave, indicating the transition region between the low- and high-energy components of the spectral energy distribution (SED). VLBA observation detected a synchrotron spectrum self-absorption turnover in the innermost part of the radio jet appearing to be elongated and inhomogeneous, and constrained the average magnetic field there to be less than 3 G. Over the following months, BL Lac appeared variable in gamma rays, showing flares (in 2009 April and 2010 January). There is no evidence for the correlation of gamma rays with the optical flux monitored from the ground in 18 months. The SED may be described by a single-zone or a two-zone synchrotron self-Compton (SSC) model, but a hybrid SSC plus external radiation Compton model seems to be preferred based on the observed variability and the fact that it provides a fit closest to equipartition.« less

The environment of x ray selected BL Lacs: Host galaxies and galaxy clustering

NASA Technical Reports Server (NTRS)

Wurtz, Ron; Stocke, John T.; Ellingson, Erica; Yee, Howard K. C.

1993-01-01

Using the Canada-France-Hawaii Telescope, we have imaged a complete, flux-limited sample of Einstein Medium Sensitivity Survey BL Lacertae objects in order to study the properties of BL Lac host galaxies and to use quantitative methods to determine the richness of their galaxy cluster environments.

Discovery of VHE γ -ray emission from the BL Lacertae object B3 2247+381 with the MAGIC telescopes

DOE PAGES

Aleksić, J.; Alvarez, E. A.; Antonelli, L. A.; ...

2012-03-02

Here, we study the non-thermal jet emission of the BL Lac object B3 2247+381 during a high optical state. The MAGIC telescopes observed the source during 13 nights between September 30th and October 30th 2010, collecting a total of 14.2 h of good quality very high energy (VHE) γ-ray data. Simultaneous multiwavelength data was obtained with X-ray observations by the Swift satellite and optical R-band observations at the KVA-telescope. We also use high energy γ-ray (HE, 0.1-100 GeV) data from the Fermi satellite. We also dedected the BL Lac object B3 2247+381 (z = 0.119) , for the first time,more » at VHE γ-rays at a statistical significance of 5.6σ. A soft VHE spectrum with a photon index of -3.2 ± 0.6 was determined. No significant short term flux variations were found. Finally, we model the spectral energy distribution using a one-zone SSC-model, which can successfully describe our data.« less

Telephone system operations evaluation : before AOS implementation

DOT National Transportation Integrated Search

1999-01-01

This study provides a detailed baseline analysis of telephone system performance before AOS : implementation. By the time of the preparation of this report, the phone system component of : AOS had not been implemented.

AATA AOS evaluation : transfer and on-time performance study : before and after AOS implementation, October 1996 - May 1999

DOT National Transportation Integrated Search

1999-01-01

This study develops, using data before AOS in 1996 and 1997 and after AOS in 1998 and 1999, implementation data on AATAs on-time performance and vehicle-to-vehicle timing of transfers at four major transfer location. Systematic evaluation of on-ti...

SIMULTANEOUS B'V'R' MONITORING OF BL LACERTAE OBJECT S5 0716+714 AND DETECTION OF INTER-BAND TIME DELAY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu Jianghua; He Xiangtao; Boettcher, Markus

We present the results of our optical monitoring of the BL Lac object S5 0716+714 over seven nights in 2006 December. The monitoring was carried out simultaneously at three optical wavelengths with a novel photometric system. The object did not show large-amplitude internight variations during this period. Intranight variations were observed on four nights and probably on one more. Strong bluer-when-brighter chromatism was detected on both intranight and internight timescales. The intranight variation amplitude decreases in the wavelength sequence of B', R', and V'. Cross-correlation analyses revealed that the variability at the B' and V' bands leads that at themore » R' band by about 30 minutes on one night.« less

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.

Catalog of SAS-2 gamma-ray observations (Fichtel, et al. 1990)

NASA Technical Reports Server (NTRS)

Warren, Wayne H., Jr.

1990-01-01

The machine-readable version of the catalog, as it is currently being distributed from the Astronomical Data Center, is described. The SAS-2 gamma ray catalog contains fluxes measured with the high energy gamma ray telescope flown aboard the second NASA Small Astronomy Satellite. The objects measured include various types of galaxies, quasi-stellar, and BL Lacertae objects, and pulsars. The catalog contains separate files for galaxies, pulsars, other objects, notes, and references.

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

Discovery of hard-spectrum γ -ray emission from the BL Lacertae object 1ES 0414+009

DOE PAGES

Abramowski, A.

2012-02-01

1ES 0414 + 009 (z = 0.287) is a distant high-frequency-peaked BL Lac object, and has long been considered a likely emitter of very-high-energy (VHE, E > 100 GeV) γ-rays due to its high X-ray and radio flux. Observations in the VHE γ-ray band and across the electromagnetic spectrum can provide insights into the origin of highly energetic particles present in the source and the radiation processes at work. Because of the distance of the source, the γ-ray spectrum might provide further limits on the level of the extragalactic background light (EBL). Methods. We report observations made between October 2005more » and December 2009 with H.E.S.S., an array of four imaging atmospheric Cherenkov telescopes. Observations at high energies (HE, 100 MeV–100 GeV) with the Fermi-LAT instrument in the first 20 months of its operation are also reported. To complete the multi-wavelength picture, archival UV and X-ray observations with the Swift satellite and optical observations with the ATOM telescope are also used. Based on the observations with H.E.S.S., 1ES 0414 + 009 is detected for the first time in the VHE band. An excess of 224 events is measured, corresponding to a significance of 7.8σ. The photon spectrum of the source is well described by a power law, with photon index of ΓVHE = 3.45 ± 0.25stat ± 0.20syst. The integral flux above 200 GeV is (1.88 ± 0.20stat ± 0.38syst) × 10-12 cm-2 s-1. Observations with the Fermi-LAT in the first 20 months of operation show a flux between 200 MeV and 100 GeV of (2.3 ± 0.2stat) × 10-9 erg cm-2 s-1, and a spectrum well described by a power-law function with a photon index ΓHE = 1.85 ± 0.18. Swift/XRT observations show an X-ray flux between 2 and 10 keV of (0.8-1) × 10-11 erg cm-2 s-1, and a steep spectrum ΓX = (2.2-2.3). Combining X-ray with optical-UV data, a fit with a log-parabolic function locates the synchrotron peak around 0.1 keV. Although the GeV–TeV observations do not provide better constraints on the EBL

X-Ray and TeV Gamma-Ray Emission from Parallel Electron-Positron or Electron-Proton Beams in BL Lacertae Objects

NASA Astrophysics Data System (ADS)

Krawczynski, H.

2007-04-01

In this paper we discuss models of the X-ray and TeV γ-ray emission from BL Lac objects based on parallel electron-positron or electron-proton beams that form close to the central black hole, due to the strong electric fields generated by the accretion disk and possibly also by the black hole itself. Fitting the energy spectrum of the BL Lac object Mrk 501, we obtain tight constraints on the beam properties. Launching a sufficiently energetic beam requires rather strong magnetic fields close to the black hole (~100-1000 G). However, the model fits imply that the magnetic field in the emission region is only ~0.02 G. Thus, the particles are accelerated close to the black hole and propagate a considerable distance before instabilities trigger the dissipation of energy through synchrotron and self-Compton emission. We discuss various approaches to generate enough power to drive the jet and, at the same time, to accelerate particles to ~20 TeV energies. Although the parallel beam model has its own problems, it explains some of the long-standing problems that plague models based on Fermi-type particle acceleration, such as the presence of a very high minimum Lorentz factor of accelerated particles. We conclude with a brief discussion of the implications of the model for the difference between the processes of jet formation in BL Lac-type objects and those in quasars.

Subaru SCExAO First-Light Direct Imaging of a Young Debris Disk around HD 36546

NASA Technical Reports Server (NTRS)

Currie, Thayne; Guyon, Olivier; Tamura, Motohide; Kudo, Tomoyuki; Jovanovic, Nemanja; Lozi, Julien; Schlieder, Joshua E.; Brandt, TImothy D.; Kuhn, Jonasa; Serabyn, Eugene;

Suppression of Plant Immune Responses by the Pseudomonas savastanoi pv. savastanoi NCPPB 3335 Type III Effector Tyrosine Phosphatases HopAO1 and HopAO2

PubMed Central

Castañeda-Ojeda, María Pilar; Moreno-Pérez, Alba; Ramos, Cayo; López-Solanilla, Emilia

2017-01-01

The effector repertoire of the olive pathogen P. savastanoi pv. savastanoi NCPPB 3335 includes two members of the HopAO effector family, one of the most diverse T3E families of the P. syringae complex. The study described here explores the phylogeny of these dissimilar members, HopAO1 and HopAO2, among the complex and reveals their activities as immune defense suppressors. Although HopAO1 is predominantly encoded by phylogroup 3 strains isolated from woody organs of woody hosts, both HopAO1 and HopAO2 are phylogenetically clustered according to the woody/herbaceous nature of their host of isolation, suggesting host specialization of the HopAO family across the P. syringae complex. HopAO1 and HopAO2 translocate into plant cells and show hrpL-dependent expression, which allows their classification as actively deployed type III effectors. Our data also show that HopAO1 and HopAO2 possess phosphatase activity, a hallmark of the members of this family. Both of them exert an inhibitory effect on early plant defense responses, such as ROS production and callose deposition, and are able to suppress ETI responses induced by the effectorless polymutant of P. syringae pv. tomato DC3000 (DC3000D28E) in Nicotiana. Moreover, we demonstrate that a ΔhopAO1 mutant of P. savastanoi NCPBB 3335 exhibits a reduced fitness and virulence in olive plants, which supports the relevance of this effector during the interaction of this strain with its host plants. This work contributes to the field with the first report regarding functional analysis of HopAO homologs encoded by P. syringae or P. savastanoi strains isolated from woody hosts. PMID:28529516

The simultaneous low state spectral energy distribution of 1ES 2344+514 from radio to very high energies

DOE PAGES

Aleksić, J.; Antonelli, L. A.; Antoranz, P.; ...

2013-07-31

Here, BL Lacertae objects are variable at all energy bands on time scales down to minutes. To construct and interpret their spectral energy distribution (SED), simultaneous broad-band observations are mandatory. Up to now, the number of objects studied during such campaigns is very limited and biased towards high flux states. Furthermore, we present the results of a dedicated multi-wavelength study of the high-frequency peaked BL Lacertae (HBL) object and known TeV emitter 1ES 2344+514 by means of a pre-organised campaign. The observations were conducted during simultaneous visibility windows of MAGIC and AGILE in late 2008. The measurements were complemented bymore » Metsähovi, RATAN-600, KVA+Tuorla, Swift and VLBA pointings. Additional coverage was provided by the ongoing long-term F-GAMMA and MOJAVE programs, the OVRO 40-m and CrAO telescopes as well as the Fermi satellite. The obtained SEDs are modelled using a one-zone as well as a self-consistent two-zone synchrotron self-Compton model. As a result, 1ES 2344+514 was found at very low flux states in both X-rays and very high energy gamma rays. Variability was detected in the low frequency radio and X-ray bands only, where for the latter a small flare was observed. The X-ray flare was possibly caused by shock acceleration characterised by similar cooling and acceleration time scales. MOJAVE VLBA monitoring reveals a static jet whose components are stable over time scales of eleven years, contrary to previous findings. There appears to be no significant correlation between the 15 GHz and R-band monitoring light curves. The observations presented here constitute the first multi-wavelength campaign on 1ES 2344+514 from radio to VHE energies and one of the few simultaneous SEDs during low activity states. The quasi-simultaneous Fermi-LAT data poses some challenges for SED modelling, but in general the SEDs are described well by both applied models. The resulting parameters are typical for TeV emitting HBLs

BL Lacertae: X-ray spectral evolution and a black-hole mass estimate

NASA Astrophysics Data System (ADS)

Titarchuk, Lev; Seifina, Elena

2017-06-01

We present an analysis of the spectral properties observed in X-rays from active galactic nucleus BL Lacertae using RXTE, Suzaku, ASCA, BeppoSAX, and Swift observations. The total time covered by these observations is approximately 20 yr. We show strong observational evidence that this source undergoes X-ray spectral transitions from the low hard state (LHS) through the intermediate state (IS) to the high soft state (HSS) during these observations. During the RXTE observations (1997-2001, 180 ks, for a total 145 datasets), the source was approximately 75%, 20% and only 5% of the time in the IS, LHS, and HSS, respectively. We also used Swift observations (470 datasets, for a total 800 ks), which occurred during 12 yr (2005-2016), the broadband (0.3-200 keV) data of BeppoSAX (1997-2000, 160 ks), and the low X-ray energy (0.3-10 keV) data of ASCA (1995-1999, 160 ks). Two observations of Suzaku (2006, 2013; 50 ks) in combinations with long-term RXTE and Swift data-sets fortunately allow us to describe all spectral states of BL Lac. The spectra of BL Lac are well fitted by the so-called bulk motion Comptonization (BMC) model for all spectral states. We have established the photon index saturation level, Γsat = 2.2 ± 0.1, in the Γ versus mass accretion rate (Ṁ) correlation. This Γ - Ṁ correlation allows us to estimate the black-hole (BH) mass in BL Lac to be MBH 3 × 107M⊙ for a distance of 300 Mpc. For the BH mass estimate, we use the scaling method taking stellar-mass Galactic BHs 4U 1543-47 and GX 339-4 as reference sources. The Γ - Ṁ correlation revealed in BL Lac is similar to those in a number of stellar-mass Galactic BHs and two recently studied intermediate-mass extragalactic BHs. It clearly shows the correlation along with the very extended Γ saturation at 2.2. This is robust observational evidence for the presence of a BH in BL Lac. We also reveal that the seed (disk) photon temperatures are relatively low, of order of 100 eV, which are consistent

Lacerta I and Cassiopeia III. Two Luminous and Distant Andromeda Satellite Dwarf Galaxies Found in the 3π Pan-STARRS1 Survey

NASA Astrophysics Data System (ADS)

Martin, Nicolas F.; Slater, Colin T.; Schlafly, Edward F.; Morganson, Eric; Rix, Hans-Walter; Bell, Eric F.; Laevens, Benjamin P. M.; Bernard, Edouard J.; Ferguson, Annette M. N.; Finkbeiner, Douglas P.; Burgett, William S.; Chambers, Kenneth C.; Hodapp, Klaus W.; Kaiser, Nicholas; Kudritzki, Rolf-Peter; Magnier, Eugene A.; Morgan, Jeffrey S.; Price, Paul A.; Tonry, John L.; Wainscoat, Richard J.

2013-07-01

We report the discovery of two new dwarf galaxies, Lacerta I/Andromeda XXXI (Lac I/And XXXI) and Cassiopeia III/Andromeda XXXII (Cas III/And XXXII), in stacked Pan-STARRS1 r P1- and i P1-band imaging data. Both are luminous systems (MV ~ -12) located at projected distances of 20.°3 and 10.°5 from M31. Lac I and Cas III are likely satellites of the Andromeda galaxy with heliocentric distances of 756^{+44}_{-28}\\,kpc and 772^{+61}_{-56}\\,kpc, respectively, and corresponding M31-centric distances of 275 ± 7 kpc and 144^{+6}_{-4}\\,kpc. The brightest of recent Local Group member discoveries, these two new dwarf galaxies owe their late discovery to their large sizes (r_h = 4.2^{+0.4}_{-0.5} arcmin or 912^{+124}_{-93}\\,pc for Lac I r_h = 6.5^{+1.2}_{-1.0} arcmin or 1456 ± 267 pc for Cas III) and consequently low surface brightness (μ0 ~ 26.0 mag arcsec-2), as well as to the lack of a systematic survey of regions at large radii from M31, close to the Galactic plane. This latter limitation is now alleviated by the 3π Pan-STARRS1 survey, which could lead to the discovery of other distant Andromeda satellite dwarf galaxies.

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

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deneva, J. S.; Stovall, K.; Martinez, J. G.

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 pulsarsmore » 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.« less

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.

Multiple approaches to detect outliers in a genome scan for selection in ocellated lizards (Lacerta lepida) along an environmental gradient.

PubMed

Nunes, Vera L; Beaumont, Mark A; Butlin, Roger K; Paulo, Octávio S

2011-01-01

Identification of loci with adaptive importance is a key step to understand the speciation process in natural populations, because those loci are responsible for phenotypic variation that affects fitness in different environments. We conducted an AFLP genome scan in populations of ocellated lizards (Lacerta lepida) to search for candidate loci influenced by selection along an environmental gradient in the Iberian Peninsula. This gradient is strongly influenced by climatic variables, and two subspecies can be recognized at the opposite extremes: L. lepida iberica in the northwest and L. lepida nevadensis in the southeast. Both subspecies show substantial morphological differences that may be involved in their local adaptation to the climatic extremes. To investigate how the use of a particular outlier detection method can influence the results, a frequentist method, DFDIST, and a Bayesian method, BayeScan, were used to search for outliers influenced by selection. Additionally, the spatial analysis method was used to test for associations of AFLP marker band frequencies with 54 climatic variables by logistic regression. Results obtained with each method highlight differences in their sensitivity. DFDIST and BayeScan detected a similar proportion of outliers (3-4%), but only a few loci were simultaneously detected by both methods. Several loci detected as outliers were also associated with temperature, insolation or precipitation according to spatial analysis method. These results are in accordance with reported data in the literature about morphological and life-history variation of L. lepida subspecies along the environmental gradient. © 2010 Blackwell Publishing Ltd.

Center for Adaptive Optics | AO Summer School

Science.gov Websites

School on Adaptive Optics Sponsored by: Center for Adaptive Optics The AO Summer School instruction is Adaptive Optics and their implementation. Our Summer School is intended to facilitate and encourage previous summer school web pages. Please contact us, if you would like more information on AO Summer School

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.

Subaru/SCExAO First-light Direct Imaging of a Young Debris Disk around HD 36546

NASA Astrophysics Data System (ADS)

Currie, Thayne; Guyon, Olivier; Tamura, Motohide; Kudo, Tomoyuki; Jovanovic, Nemanja; Lozi, Julien; Schlieder, Joshua E.; Brandt, Timothy D.; Kuhn, Jonas; Serabyn, Eugene; Janson, Markus; Carson, Joseph; Groff, Tyler; Kasdin, N. Jeremy; McElwain, Michael W.; Singh, Garima; Uyama, Taichi; Kuzuhara, Masayuki; Akiyama, Eiji; Grady, Carol; Hayashi, Saeko; Knapp, Gillian; Kwon, Jung-mi; Oh, Daehyeon; Wisniewski, John; Sitko, Michael; Yang, Yi

2017-02-01

We present H-band scattered light imaging of a bright debris disk around the A0 star HD 36546 obtained from the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system with data recorded by the HiCIAO camera using the vector vortex coronagraph. SCExAO traces the disk from r ˜ 0.″3 to r ˜ 1″ (34-114 au). The disk is oriented in a near east-west direction (PA ˜ 75°), is inclined by I ˜ 70°-75°, and is strongly forward-scattering (g > 0.5). It is an extended disk rather than a sharp ring; a second, diffuse dust population extends from the disk’s eastern side. While HD 36546 intrinsic properties are consistent with a wide age range (t ˜ 1-250 Myr), its kinematics and analysis of coeval stars suggest a young age (3-10 Myr) and a possible connection to Taurus-Auriga’s star formation history. SCExAO’s planet-to-star contrast ratios are comparable to the first-light Gemini Planet Imager contrasts; for an age of 10 Myr, we rule out planets with masses comparable to HR 8799 b beyond a projected separation of 23 au. A massive icy planetesimal disk or an unseen super-Jovian planet at r > 20 au may explain the disk’s visibility. The HD 36546 debris disk may be the youngest debris disk yet imaged, is the first newly identified object from the now-operational SCExAO extreme AO system, is ideally suited for spectroscopic follow-up with SCExAO/CHARIS in 2017, and may be a key probe of icy planet formation and planet-disk interactions.

Multiwavelength monitoring of the BL Lacertae object PKS 2155-304. 3: Ground-based observations in 1991 November

NASA Technical Reports Server (NTRS)

Courvoisier, T. J.-L.; Blecha, A.; Bouchet, P.; Bratschi, P.; Carini, M. T.; Donahue, M.; Edelson, R.; Feigelson, E. D.; Filippenko, A. V.; Glass, I. S.

1995-01-01

We present ground-based observations of the BL Lac object PKS 2155-304 during 1991 November. These data were obtained as part of a large international campaign of observations spanning the electro-magnetic spectrum from the radio waves to the X-rays. The data presented here include radio and UBVRI fluxes, as well as optical polarimetry. The U to I data show the same behavior in all bands and that only upper limits to any lag can be deduced from the cross-correlation of the light curves. The spectral slope in the U-I domain remained constant on all epochs but 2. There is no correlation between changes in the spectral slope and large variations in the total or polarized flux. The radio flux variations did not follow the same pattern of variability as the optical and infrared fluxes. The polarized flux varied by a larger factor than the total flux. The variations of the polarized flux are poorly correlated with those of the total flux in the optical (and hence UV domain; see the accompanying paper by Edelson et al.) nor with those of the soft X-rays. We conclude that the variability of PKS 2155-304 in the optical and near-infrared spectral domains are easier to understand in the context of variable geometry or bulk Lorentz factor than of variable electron acceleration and cooling rates.

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.

AO Images of Asteroids, Inverting their Lightcurves, and SSA

DTIC Science & Technology

2008-09-01

telescopes, we have recently obtained images of Main- Belt asteroids with adaptive optics (AO) on the Keck-II 10 meter telescope, the world’s largest...telescopes, we have recently obtained images of Main- Belt asteroids with adaptive optics (AO) on the Keck-II 10 meter telescope, the world’s largest...AO Images of Asteroids , Inverting their Lightcurves, and SSA Jack Drummond a and Julian Christoub,c aStarfire Optical Range, Directed Energy

[Searching for Rare Celestial Objects Automatically from Stellar Spectra of the Sloan Digital Sky Survey Data Release Eight].

PubMed

Si, Jian-min; Luo, A-li; Wu, Fu-zhao; Wu, Yi-hong

2015-03-01

There are many valuable rare and unusual objects in spectra dataset of Sloan Digital Sky Survey (SDSS) Data Release eight (DR8), such as special white dwarfs (DZ, DQ, DC), carbon stars, white dwarf main-sequence binaries (WDMS), cataclysmic variable (CV) stars and so on, so it is extremely significant to search for rare and unusual celestial objects from massive spectra dataset. A novel algorithm based on Kernel dense estimation and K-nearest neighborhoods (KNN) has been presented, and applied to search for rare and unusual celestial objects from 546 383 stellar spectra of SDSS DR8. Their densities are estimated using Gaussian kernel density estimation, the top 5 000 spectra in descend order by their densities are selected as rare objects, and the top 300 000 spectra in ascend order by their densities are selected as normal objects. Then, KNN were used to classify the rest objects, and simultaneously K nearest neighbors of the 5 000 rare spectra are also selected as rare objects. As a result, there are totally 21 193 spectra selected as initial rare spectra, which include error spectra caused by deletion, redden, bad calibration, spectra consisting of different physically irrelevant components, planetary nebulas, QSOs, special white dwarfs (DZ, DQ, DC), carbon stars, white dwarf main-sequence binaries (WDMS), cataclysmic variable (CV) stars and so on. By cross identification with SIMBAD, NED, ADS and major literature, it is found that three DZ white dwarfs, one WDMS, two CVs with company of G-type star, three CVs candidates, six DC white dwarfs, one DC white dwarf candidate and one BL Lacertae (BL lac) candidate are our new findings. We also have found one special DA white dwarf with emission lines of Ca II triple and Mg I, and one unknown object whose spectrum looks like a late M star with emission lines and its image looks like a galaxy or nebula.

Comprehensive thermoelectric properties of n- and p-type 78a/o Si - 22a/o Ge alloy

NASA Technical Reports Server (NTRS)

Raag, V.

1978-01-01

The time and temperature dependence of the thermoelectric properties on n- and p-type 78 a/o Si - 22 a/o Ge alloy are presented in detail for the range of temperatures of zero to 1000 C and operating times up to twelve years. The mechanisms responsible for the time dependence of the properties are discussed and mathematical models used in the derivation of the property values from experimental data are presented. The thermoelectric properties for each polarity type of the alloy are presented as a function of temperature for various operating times.

Visible AO Observations at Halpha for Accreting Young Planets

NASA Astrophysics Data System (ADS)

Close, L. M.; Follette, K.; Males, J. R.; Morzinski, K.; Rodigas, T. J.; Hinz, P.; Wu, Y.-L.; Apai, D.; Najita, J.; Puglisi, A.; Esposito, S.; Riccardi, A.; Bailey, V.; Xompero, M.; Briguglio, R.; Weinberger, A.

2014-01-01

We utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high-resolution science in the visible with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.5-0.7'') we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60s) r' (0.63μm) images are slightly coarser at FWHM = 23-29 mas (Strehl ~ 28%) with bright (R < 9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young (~ 1 Myr) Orion Trapezium θ1 Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary θ1 Ori C 1 C 2 was easily resolved in non-interferometric images for the first time. Relative positions of the bright trapezium binary stars were measured with ~ 0.6-5 mas accuracy. In the second commissioning run we were able to correct 378 modes and achieved good contrasts (Strehl>20% on young transition disks at Hα). We discuss the contrasts achieved at Hα and the possibility of detecting low mass (~ 1-5 Mjup) planets (past 5AU) with our new SAPPHIRES survey with MagAO at Hα.

Subaru/SCExAO First-light Direct Imaging of a Young Debris Disk around HD 36546

DOE Office of Scientific and Technical Information (OSTI.GOV)

Currie, Thayne; Guyon, Olivier; Kudo, Tomoyuki

We present H -band scattered light imaging of a bright debris disk around the A0 star HD 36546 obtained from the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system with data recorded by the HiCIAO camera using the vector vortex coronagraph. SCExAO traces the disk from r ∼ 0.″3 to r ∼1″ (34–114 au). The disk is oriented in a near east–west direction (PA ∼ 75°), is inclined by i ∼ 70°–75°, and is strongly forward-scattering (g > 0.5). It is an extended disk rather than a sharp ring; a second, diffuse dust population extends from the disk’s eastern side. Whilemore » HD 36546 intrinsic properties are consistent with a wide age range (t ∼ 1–250 Myr), its kinematics and analysis of coeval stars suggest a young age (3–10 Myr) and a possible connection to Taurus-Auriga’s star formation history. SCExAO’s planet-to-star contrast ratios are comparable to the first-light Gemini Planet Imager contrasts; for an age of 10 Myr, we rule out planets with masses comparable to HR 8799 b beyond a projected separation of 23 au. A massive icy planetesimal disk or an unseen super-Jovian planet at r > 20 au may explain the disk’s visibility. The HD 36546 debris disk may be the youngest debris disk yet imaged, is the first newly identified object from the now-operational SCExAO extreme AO system, is ideally suited for spectroscopic follow-up with SCExAO/CHARIS in 2017, and may be a key probe of icy planet formation and planet–disk interactions.« less

Phylogeography and demographic history of Lacerta lepida in the Iberian Peninsula: multiple refugia, range expansions and secondary contact zones

PubMed Central

2011-01-01

Background The Iberian Peninsula is recognized as an important refugial area for species survival and diversification during the climatic cycles of the Quaternary. Recent phylogeographic studies have revealed Iberia as a complex of multiple refugia. However, most of these studies have focused either on species with narrow distributions within the region or species groups that, although widely distributed, generally have a genetic structure that relates to pre-Quaternary cladogenetic events. In this study we undertake a detailed phylogeographic analysis of the lizard species, Lacerta lepida, whose distribution encompasses the entire Iberian Peninsula. We attempt to identify refugial areas, recolonization routes, zones of secondary contact and date demographic events within this species. Results Results support the existence of 6 evolutionary lineages (phylogroups) with a strong association between genetic variation and geography, suggesting a history of allopatric divergence in different refugia. Diversification within phylogroups is concordant with the onset of the Pleistocene climatic oscillations. The southern regions of several phylogroups show a high incidence of ancestral alleles in contrast with high incidence of recently derived alleles in northern regions. All phylogroups show signs of recent demographic and spatial expansions. We have further identified several zones of secondary contact, with divergent mitochondrial haplotypes occurring in narrow zones of sympatry. Conclusions The concordant patterns of spatial and demographic expansions detected within phylogroups, together with the high incidence of ancestral haplotypes in southern regions of several phylogroups, suggests a pattern of contraction of populations into southern refugia during adverse climatic conditions from which subsequent northern expansions occurred. This study supports the emergent pattern of multiple refugia within Iberia but adds to it by identifying a pattern of refugia coincident

Phylogeography and demographic history of Lacerta lepida in the Iberian Peninsula: multiple refugia, range expansions and secondary contact zones.

PubMed

Miraldo, Andreia; Hewitt, Godfrey M; Paulo, Octavio S; Emerson, Brent C

2011-06-17

The Iberian Peninsula is recognized as an important refugial area for species survival and diversification during the climatic cycles of the Quaternary. Recent phylogeographic studies have revealed Iberia as a complex of multiple refugia. However, most of these studies have focused either on species with narrow distributions within the region or species groups that, although widely distributed, generally have a genetic structure that relates to pre-Quaternary cladogenetic events. In this study we undertake a detailed phylogeographic analysis of the lizard species, Lacerta lepida, whose distribution encompasses the entire Iberian Peninsula. We attempt to identify refugial areas, recolonization routes, zones of secondary contact and date demographic events within this species. Results support the existence of 6 evolutionary lineages (phylogroups) with a strong association between genetic variation and geography, suggesting a history of allopatric divergence in different refugia. Diversification within phylogroups is concordant with the onset of the Pleistocene climatic oscillations. The southern regions of several phylogroups show a high incidence of ancestral alleles in contrast with high incidence of recently derived alleles in northern regions. All phylogroups show signs of recent demographic and spatial expansions. We have further identified several zones of secondary contact, with divergent mitochondrial haplotypes occurring in narrow zones of sympatry. The concordant patterns of spatial and demographic expansions detected within phylogroups, together with the high incidence of ancestral haplotypes in southern regions of several phylogroups, suggests a pattern of contraction of populations into southern refugia during adverse climatic conditions from which subsequent northern expansions occurred. This study supports the emergent pattern of multiple refugia within Iberia but adds to it by identifying a pattern of refugia coincident with the southern distribution

Model-based wavefront sensorless adaptive optics system for large aberrations and extended objects.

PubMed

Yang, Huizhen; Soloviev, Oleg; Verhaegen, Michel

2015-09-21

A model-based wavefront sensorless (WFSless) adaptive optics (AO) system with a 61-element deformable mirror is simulated to correct the imaging of a turbulence-degraded extended object. A fast closed-loop control algorithm, which is based on the linear relation between the mean square of the aberration gradients and the second moment of the image intensity distribution, is used to generate the control signals for the actuators of the deformable mirror (DM). The restoration capability and the convergence rate of the AO system are investigated with different turbulence strength wave-front aberrations. Simulation results show the model-based WFSless AO system can restore those images degraded by different turbulence strengths successfully and obtain the correction very close to the achievable capability of the given DM. Compared with the ideal correction of 61-element DM, the averaged relative error of RMS value is 6%. The convergence rate of AO system is independent of the turbulence strength and only depends on the number of actuators of DM.

Robo-AO KOI Survey: LGS-AO imaging of every Kepler planetary candidate host star

NASA Astrophysics Data System (ADS)

Ziegler, Carl; Law, Nicholas; Baranec, Christoph; Riddle, Reed

2018-01-01

Robo-AO is observing every Kepler planetary candidate host star (KOI) in high resolution, made possible using the unprecedented efficiency provided by automation of LGS adaptive optics. Nearby contaminating stars may be the source of false positive transit signals or, if a bona fide planet is in the system, dilute the observed transit signal, resulting in underestimated planet radii. In 3857 observations, we find 632 stars within 4" (approximately the Kepler pixel scale) of KOIs. In particular, we find 26 rocky, habitable zone planets with contaminating nearby stars, 8 of which are now more likely to have large gaseous envelopes. We present evidence that the majority of these nearby stars are unbound, and use the likely bound stars to test theories of planetary formation and evolution within multiple star systems. Finally, we discuss future all-sky, kilo-target surveys made possible by the construction of a Southern Robo-AO analog.

Identification of the linkage group of the Z sex chromosomes of the sand lizard (Lacerta agilis, Lacertidae) and elucidation of karyotype evolution in lacertid lizards.

PubMed

Srikulnath, Kornsorn; Matsubara, Kazumi; Uno, Yoshinobu; Nishida, Chizuko; Olsson, Mats; Matsuda, Yoichi

2014-12-01

The sand lizard (Lacerta agilis, Lacertidae) has a chromosome number of 2n = 38, with 17 pairs of acrocentric chromosomes, one pair of microchromosomes, a large acrocentric Z chromosome, and a micro-W chromosome. To investigate the process of karyotype evolution in L. agilis, we performed chromosome banding and fluorescent in situ hybridization for gene mapping and constructed a cytogenetic map with 86 functional genes. Chromosome banding revealed that the Z chromosome is the fifth largest chromosome. The cytogenetic map revealed homology of the L. agilis Z chromosome with chicken chromosomes 6 and 9. Comparison of the L. agilis cytogenetic map with those of four Toxicofera species with many microchromosomes (Elaphe quadrivirgata, Varanus salvator macromaculatus, Leiolepis reevesii rubritaeniata, and Anolis carolinensis) showed highly conserved linkage homology of L. agilis chromosomes (LAG) 1, 2, 3, 4, 5(Z), 7, 8, 9, and 10 with macrochromosomes and/or macrochromosome segments of the four Toxicofera species. Most of the genes located on the microchromosomes of Toxicofera were localized to LAG6, small acrocentric chromosomes (LAG11-18), and a microchromosome (LAG19) in L. agilis. These results suggest that the L. agilis karyotype resulted from frequent fusions of microchromosomes, which occurred in the ancestral karyotype of Toxicofera and led to the disappearance of microchromosomes and the appearance of many small macrochromosomes.

LACERTA I AND CASSIOPEIA III. TWO LUMINOUS AND DISTANT ANDROMEDA SATELLITE DWARF GALAXIES FOUND IN THE 3{pi} PAN-STARRS1 SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Nicolas F.; Laevens, Benjamin P. M.; Slater, Colin T.

We report the discovery of two new dwarf galaxies, Lacerta I/Andromeda XXXI (Lac I/And XXXI) and Cassiopeia III/Andromeda XXXII (Cas III/And XXXII), in stacked Pan-STARRS1 r{sub P1}- and i{sub P1}-band imaging data. Both are luminous systems (M{sub V} {approx} -12) located at projected distances of 20. Degree-Sign 3 and 10. Degree-Sign 5 from M31. Lac I and Cas III are likely satellites of the Andromeda galaxy with heliocentric distances of 756{sup +44}{sub -28} kpc and 772{sup +61}{sub -56} kpc, respectively, and corresponding M31-centric distances of 275 {+-} 7 kpc and 144{sup +6}{sub -4} kpc. The brightest of recent Local Groupmore » member discoveries, these two new dwarf galaxies owe their late discovery to their large sizes (r{sub h} = 4.2{sup +0.4}{sub -0.5} arcmin or 912{sup +124}{sub -93} pc for Lac I; r{sub h} = 6.5{sup +1.2}{sub -1.0} arcmin or 1456 {+-} 267 pc for Cas III) and consequently low surface brightness ({mu}{sub 0} {approx} 26.0 mag arcsec{sup -2}), as well as to the lack of a systematic survey of regions at large radii from M31, close to the Galactic plane. This latter limitation is now alleviated by the 3{pi} Pan-STARRS1 survey, which could lead to the discovery of other distant Andromeda satellite dwarf galaxies.« less

Adaptive optics for MOSAIC: design and performance of the wide(st)-field AO system for the E-ELT

NASA Astrophysics Data System (ADS)

Morris, Tim; Basden, Alastair; Buey, Tristan; Chemla, Fanny; Conan, Jean-Marc; Fitzsimons, Ewan; Fusco, Thierry; Gendron, Eric; Hammer, Francois; Jagourel, Pascal; Morel, Carine; Myers, Richard; Neichel, Benoit; Petit, Cyril; Rodrigues, Myriam; Rousset, Gérard

2016-07-01

MOSAIC is the proposed multiple-object spectrograph for the E-ELT that will utilise the widest possible field of view provided by the telescope. In terms of adaptive optics, there are two distinct operating modes required to meet the top-level science requirements. The MOSAIC High Multiplex Mode (HMM) requires either seeing-limited or GLAO correction within a 0.6 (NIR) and 0.9 (VIS) arcsecond sub-fields over the widest possible field for a few hundred objects. To achieve seeing limited operation whilst maintaining the maximum unvignetted field of view for scientific observation will require recreating some of the functionality present in the Pre-Focal Station relating to control of the E-ELT active optics. MOSAIC High Definition Mode Control (HDM) requires a 25% Ensquared Energy (EE) within 150mas in the H-band element for approximately 10 targets distributed across the full E-ELT field, implying the use of Multiple Object AO (MOAO). Initial studies have shown that to meet the EE requirements whilst maintaining high-sky coverage will require the combination of wavefront signals from both high-order NGS and LGS to provide a tomographic estimate for the correction to be applied to the open-loop MOAO DMs. In this paper we present the current MOSAIC AO design and provide the first performance estimates for the baseline instrument design. We then report on the various trade-offs that will be investigated throughout the course of the Phase A study, such as the requirement to mix NGS and LGS signals tomographically. Finally, we discuss how these will impact the AO architecture, the MOSAIC design and ultimately the scientific performance of this wide-field workhorse instrument at the E-ELT.

Use of ultrasound measurement of the inferior vena cava diameter as an objective tool in the assessment of children with clinical dehydration.

PubMed

Chen, Lei; Kim, Yunie; Santucci, Karen A

2007-10-01

Bedside ultrasonography (US) measurement of the inferior vena cava (IVC) and aorta (Ao) may be useful in objectively assessing children with dehydration. The objectives of this study were 1) to compare the IVC and Ao diameters (IVC/Ao) ratio of dehydrated children with controls and 2) to compare the IVC/Ao ratio before and after intravenous (i.v.) rehydration in children with dehydration. This prospective observational study was performed in an urban pediatric emergency department. Children between 6 months and 16 years of age with clinical evidence of dehydration were enrolled. Bedside US measurements of the IVC and Ao were taken before and immediately after i.v. fluids were administered. An age-, gender-, and weight-matched control without dehydration was enrolled for each subject. The IVC/Ao ratios of subjects and controls were compared using Wilcoxon signed rank test, as were the ratios before and after i.v. hydration for each subject. Thirty-six pairs of subjects and matched controls were enrolled. The IVC/Ao ratios in the subjects were lower as compared with controls (mean of 0.75 vs. 1.01), with a mean difference of 0.26 (95% confidence interval = 0.18 to 0.35). In subjects, the IVC/Ao ratios were significantly lower before i.v. hydration (mean of 0.75 vs. 1.09), with a mean difference of 0.34 (95% confidence interval = 0.29 to 0.39). As measured by bedside US measurement, the IVC/Ao ratio is lower in children clinically assessed to be dehydrated. Furthermore, it increases with administration of i.v. fluid boluses.

ELTs adaptive optics for multi-objects 3D spectroscopy: key parameters and design rules

NASA Astrophysics Data System (ADS)

Neichel, B.; Conan, J.-M.; Fusco, T.; Gendron, E.; Puech, M.; Rousset, G.; Hammer, F.

2006-06-01

In the last few years, new Adaptive Optics [AO] techniques have emerged to answer new astronomical challenges: Ground-Layer AO [GLAO] and Multi-Conjugate AO [MCAO] to access a wider Field of View [FoV], Multi-Object AO [MOAO] for the simultaneous observation of several faint galaxies, eXtreme AO [XAO] for the detection of faint companions. In this paper, we focus our study to one of these applications : high red-shift galaxy observations using MOAO techniques in the framework of Extremely Large Telescopes [ELTs]. We present the high-level specifications of a dedicated instrument. We choose to describe the scientific requirements with the following criteria : 40% of Ensquared Energy [EE] in H band (1.65μm) and in an aperture size from 25 to 150 mas. Considering these specifications we investigate different AO solutions thanks to Fourier based simulations. Sky Coverage [SC] is computed for Natural and Laser Guide Stars [NGS, LGS] systems. We show that specifications are met for NGS-based systems at the cost of an extremely low SC. For the LGS approach, the option of low order correction with a faint NGS is discussed. We demonstrate that, this last solution allows the scientific requirements to be met together with a quasi full SC.

Genetic variation in parthenogenetic Caucasian rock lizards of the genus Lacerta (L. dahli, L. armeniaca, L. unisexualis) analyzed by DNA fingerprinting.

PubMed

Tokarskaya, O N; Kan, N G; Petrosyan, V G; Martirosyan, I A; Grechko, V V; Danielyan, F D; Darevsky, I S; Ryskov, A P

2001-07-01

Multilocus DNA fingerprinting has been used to study the variability of some mini- and microsatellite sequences in parthenogenetic species of Caucasian rock lizards of the genus Lacerta (L. dahli, L. armeniaca and L. unisexualis). We demonstrate that these clonally reproducing lizards possess species-specific DNA fingerprints with a low degree of intra- and interpopulation variation. Mean indices of similarity obtained using M13 DNA, (GACA)4 and (TCC)50 as probes were 0.962 and 0.966 in L. dahli and L. armeniaca, respectively. The mean index of similarity obtained using M 13 and GATA probes in L. unisexualis was estimated to be 0.95. However, despite the high degree of band-sharing, variable DNA fragments were revealed in all populations with the microsatellite probes. An particularly high level of variability was observed for (TCC)n microsatellites in populations of L. unisexualis. In fact TCC-derived DNA fingerprints were close to being individual-specific, with a mean index of similarity of 0.824. Fingerprint analysis of parthenogenetic families of L. armeniaca showed that all maternal fragments were inherited together by the progeny, and no differences in fingerprint patterns were observed. On the other hand, while identical DNA fingerprints were obtained from L. unisexualis families with M13 and (GATA)4 probes, use of the (TCC)50 probe revealed remarkable intrafamily variation in this species. It is assumed that the genetic heterogeneity observed in parthenogenetic populations may be explained, at least in part, by the existence of genetically unstable microsatellite loci. Our data serve to illustrate processes of spontaneous mutagenesis and the initial stages of clonal differentiation in natural populations of the lizard species studied.

Multimodal sexual signals in male ocellated lizards Lacerta lepida: vitamin E in scent and green coloration may signal male quality in different sensory channels

NASA Astrophysics Data System (ADS)

Martín, José; López, Pilar

2010-06-01

The mechanisms that confer honesty to multiple sexual signals of vertebrates remain less known. We suggest that vitamin E in the scent (femoral secretions) and carotenoids in coloration of Lacerta lepida lizards might advertise quality because they are relevant in metabolism as major antioxidants and have a dietary origin. Results showed that there may be similar trade-offs between immunity and both chemical and visual signaling, as males with more vitamin E in secretions and those with more greenish, darker, and saturated carotenoid-dependent colorations had a higher immune response. This suggests that only high-quality males can divert from metabolism and allocate enough vitamin E to secretions and enough carotenoids to coloration. Therefore, information provided by visual and chemical signals is congruent. The use of multiple sensory channels may allow signaling a male quality under different circumstances or reinforce the reliability of the signal when both signals are perceived simultaneously. However, we also found that characteristics of carotenoid-dependent coloration mirror the amounts of vitamin E in secretions. This might support that carotenoids, which are not true antioxidants in the organism, would just reflect and “inform” on the actual contents of metabolic antioxidant vitamin E, which is part of the true system that prevent oxidation. We suggest that the metabolic roles of vitamins might be the actual basis of honesty of many sexual displays, and that carotenoid-based signals might be just the visible part of the whole system.

Steering UTC (AOS) and UTC (PL) by TA (PL)

DTIC Science & Technology

2007-01-01

UTC. • A second time-transfer technique ( TWSTFT ) will be introduced at AOS. 38th Annual Precise Time and Time Interval (PTTI) Meeting 387 • AOS will...Deviation TWSTFT – Two-Way Satellite Time and Frequency Transfer UTC – Coordinated Universal Time UTC (i) – Realization of UTC by laboratory i

DeMi Payload Progress Update and Adaptive Optics (AO) Control Comparisons – Meeting Space AO Requirements on a CubeSat

NASA Astrophysics Data System (ADS)

Grunwald, Warren; Holden, Bobby; Barnes, Derek; Allan, Gregory; Mehrle, Nicholas; Douglas, Ewan S.; Cahoy, Kerri

2018-01-01

The Deformable Mirror (DeMi) CubeSat mission utilizes an Adaptive Optics (AO) control loop to correct incoming wavefronts as a technology demonstration for space-based imaging missions, such as high contrast observations (Earthlike exoplanets) and steering light into core single mode fibers for amplification. While AO has been used extensively on ground based systems to correct for atmospheric aberrations, operating an AO system on-board a small satellite presents different challenges. The DeMi payload 140 actuator MEMS deformable mirror (DM) corrects the incoming wavefront in four different control modes: 1) internal observation with a Shack-Hartmann Wavefront Sensor (SHWFS), 2) internal observation with an image plane sensor, 3) external observation with a SHWFS, and 4) external observation with an image plane sensor. All modes have wavefront aberration from two main sources, time-invariant launch disturbances that have changed the optical path from the expected path when calibrated in the lab and very low temporal frequency thermal variations as DeMi orbits the Earth. The external observation modes has additional error from: the pointing precision error from the attitude control system and reaction wheel jitter. Updates on DeMi’s mechanical, thermal, electrical, and mission design are also presented. The analysis from the DeMi payload simulations and testing provides information on the design options when developing space-based AO systems.

Examples of seismic modelling

NASA Astrophysics Data System (ADS)

Pamyatnykh, A. A.

2008-12-01

Findings of a few recent asteroseismic studies of the main sequence pulsating stars, as per- formed in Wojciech Dziembowski’s group in Warsaw and in Michel Breger’s group in Vienna, are briefly presented and discussed. The selected objects are three hybrid pulsators ν Eridani, 12 Lacertae and γ Pegasi, which show both β Cephei and SPB type modes, and the δ Scuti type star 44 Tauri.

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.

AO wavefront sensing detector developments at ESO

NASA Astrophysics Data System (ADS)

Downing, Mark; Kolb, Johann; Baade, Dietrich; Iwert, Olaf; Hubin, Norbert; Reyes, Javier; Feautrier, Philippe; Gach, Jean-Luc; Balard, Philippe; Guillaume, Christian; Stadler, Eric; Magnard, Yves

2010-07-01

The detector is a critical component of any Adaptive Optics WaveFront Sensing (AO WFS) system. The required combination of fast frame rate, high quantum efficiency, low noise, large number and size of pixels, and low image lag can often only be met by specialized custom developments. ESO's very active WFS detector development program is described. Key test results are presented for newly developed detectors: a) the e2v L3Vision CCD220 (the fastest/lowest noise AO detector to date) to be deployed soon on 2nd Generation VLT instruments, and b) the MPI-HLL pnCCD with its superb high "red" response. The development of still more advanced laser/natural guide-star WFS detectors is critical for the feasibility of ESO's EELT. The paper outlines: a) the multi-phased development plan that will ensure detectors are available on-time for EELT first-light AO systems, b) results of design studies performed by industry during 2007 including a comparison of the most promising technologies, c) results from CMOS technology demonstrators that were built and tested over the past two years to assess and validate various technologies at the pixel level, their fulfillment of critical requirements (especially read noise and speed), and scalability to full-size. The next step will be towards Scaled-Down Demonstrators (SDD) to retire architecture and process risks. The SDD will be large enough to be used for E-ELT first-light AO WFS systems. For full operability, 30-50 full-scale devices will be needed.

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

The Subaru Coronagraphic Extreme AO project: an XAO4ELT precursor

NASA Astrophysics Data System (ADS)

Martinache, F.

2011-09-01

A diffraction-limited 30-meter telescope theoretically provides a 10 mas resolution limit in the near infrared. Modern coronagraphs like the Vortex, the 8OPM and the PIAA offer the means to take full advantage of this angular resolution allowing to explore at high contrast, the innermost parts of nearby planetary systems to within a fraction of an astronomical unit: an unprecedented capability that will revolutionize our understanding of planet formation across the habitable zone. A precursor of such a system is the Subaru Coronagraphic Extreme AO project. SCExAO combines a high performance PIAA-based coronagraph downstream Subaru's AO188 AO system and a 1024-actuator MEMS DM. SCExAO employs advanced wavefront control schemes that make high contrast detection possible at 1 λ/D, providing for a few cases, the possibility to detect the light reflected by exoplanets. Moderate-high contrast detection in the super-resolution regime (<λ/D) is also possible using well calibrated closure quantities like closure-phase for a non-redundant (masked) aperture and its extension for to arbitrary apertures (Kernel-phase). Lessons learned from SCExAO's incremental deployment plan during its first 2011 engineering campaign provides insights that will guide future development of high contrast instrumentation on an ELT.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Law, Nicholas M.; Ziegler, Carl; Morton, Tim

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 designedmore » 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.« less

Discovery of high and very high-energy emission from the BL Lacertae object SHBL J001355.9-185406

NASA Astrophysics Data System (ADS)

H.E.S.S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Göring, D.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hague, J. D.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Nedbal, D.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spieß, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

2013-06-01

The detection of the high-frequency peaked BL Lac object (HBL) SHBL J001355.9-185406 (z = 0.095) at high (HE; 100 MeV < E < 300 GeV) and very high-energy (VHE; E > 100 GeV) with the Fermi Large Area Telescope (LAT) and the High Energy Stereoscopic System (H.E.S.S.) is reported. Dedicated observations were performed with the H.E.S.S. telescopes, leading to a detection at the 5.5σ significance level. The measured flux above 310 GeV is (8.3 ± 1.7stat ± 1.7sys) × 10-13 photons cm-2 s-1 (about 0.6% of that of the Crab Nebula), and the power-law spectrum has a photon index of Γ = 3.4 ± 0.5stat ± 0.2sys. Using 3.5 years of publicly available Fermi-LAT data, a faint counterpart has been detected in the LAT data at the 5.5σ significance level, with an integrated flux above 300 MeV of (9.3 ± 3.4stat ± 0.8sys) × 10-10 photons cm-2 s-1 and a photon index of Γ = 1.96 ± 0.20stat ± 0.08sys. X-ray observations with Swift-XRT allow the synchrotron peak energy in νFν representation to be located at ~1.0 keV. The broadband spectral energy distribution is modelled with a one-zone synchrotronself-Compton (SSC) model and the optical data by a black-body emission describing the thermal emission of the host galaxy. The derived parameters are typical of HBLs detected at VHE, with a particle-dominated jet.

Impact of ao-dake-humi, Japanese traditional bamboo foot stimulator, on lower urinary tract symptoms, constipation and hypersensitivity to cold: a single-arm prospective pilot study.

PubMed

Minagawa, Tomonori; Saitou, Tetsuichi; Suzuki, Toshiro; Domen, Takahisa; Yokoyama, Hitoshi; Ishikawa, Masakuni; Hirakata, Shiro; Nagai, Takashi; Nakazawa, Masaki; Ogawa, Teruyuki; Ishizuka, Osamu

2016-12-09

Ao-dake-humi is a traditional Japanese bamboo foot stimulator consisting of a half-pipe-shaped step made of bamboo used to stimulate the foot by stepping on it, and is commonly used to promote general health among the elderly in Japan. However, its efficacy has not been reported in the scientific literature. This study was performed to investigate the role of ao-dake-humi focusing on lower urinary tract symptoms (LUTS), constipation, and hypersensitivity to cold (HC). Participants with LUTS, constipation, or HC were enrolled in this study. Ao-dake-humi was used twice a day for 28 days. Before and 28 days after starting ao-dake-humi use, international prostate symptom score (IPSS), quality-of-life (QoL) score, and overactive bladder symptom score (OABSS) were measured to evaluate the efficacy of ao-dake-humi on LUTS. To evaluate the objective efficacy of ao-dake-humi on LUTS, a frequency-volume chart (FVC) was plotted in LUTS patients for 3 days. A visual analogue scale (VAS) was used to evaluate the efficacy of ao-dake-humi on constipation (VAS-constipation) and HC (VAS-HC) in the participants with constipation or HC. A total of 24 participants were enrolled in this study. Twenty-one participants had LUTS, 11 had constipation, and 17 participants had HC. IPSS, especially storage-subscore, QoL score and OABSS, decreased significantly after use of ao-dake-humi. The use of ao-dake-humi increased maximal bladder capacity, resulting in a significant decrease in urinary frequency as determined from the FVC. In accordance with the results of VAS-constipation and VAS-HC, both constipation and HC were significantly relieved after ao-dake-humi use. The results of this prospective pilot study indicated that ao-dake-humi is safe and has therapeutic efficacy in cases of LUTS, constipation and HC. The possibility of using ao-dake-humi as physical neuromodulation therapy was shown in the management of LUTS, constipation and HC. UMIN000019333 (UMIN-CTR, Registered October-15

Robo-AO M Dwarf Multiplicity Survey

NASA Astrophysics Data System (ADS)

Lamman, Claire; Baranec, Christoph; Berta-Thompson, Zachory K.; Law, Nicholas M.; Ziegler, Carl; Schonhut-Stasik, Jessica

2018-06-01

We analyzed close to 7,000 observations from Robo-AO’s field M dwarf survey taken on the 2.1m Kitt Peak telescope. Results will help determine the total multiplicity fraction and multiplicity functions of M dwarfs, which are crucial steps towards understanding their evolution and formation mechanics. Through its robotic, laser-guided, and automated system, the Robo-AO instrument has yielded the largest adaptive-optics M dwarf survey to date. I developed a graphical user interface to quickly analyze this data. Initial data analysis included assessing data quality, checking the result from Robo-AO’s automatic reduction pipeline, and determining existence as well as the relative position of companions through a visual inspection. This program can be applied to other datasets and was successfully tested by re-analyzing observations from a separate Robo-AO survey. After a conservative initial cut for quality, over 350 companions were found within 4” of a primary star out of 2,746 high quality Robo-AO M dwarf observations, including four triple systems. Further observations were done with the Keck II telescope by using its NIRC2 imager to follow up on ten select targets for the existence and physical association of companions. Future research will yield insights into low-mass stellar formation and provide a database of nearby M dwarf multiples that will potentially assist ongoing and future surveys for planets around these stars, such as the NASA TESS mission.

AO 1535 inhibits O2- production by human macrophages.

PubMed

Spampinato, G; Messina, L; Malaguarnera, L; Arcidiacono, A; Giuffrida, M A; Guarniera, E; Geremia, E; Rastrelli, A; Messina, A

1992-01-01

AO 1535 is a semisynthetic monoglycosylceramide derived from O-glycosilated sphingosine, with a chemical structure similar to the glycolipids present in many mammalian tissues. In the epidermis monoglycosylceramides contribute to consolidate the structure of cutaneous layers. It has been recently shown that sphingosine and its derivatives are potent inhibitors of Protein kinase C, and block the 'respiratory burst' of phagocitic cells. In macrophages, like in neutrophils, the reactive oxygen intermediates are produced by a membrane associated enzymatic complex, NADPH-oxidase, which is activated by Protein kinase C. This study demonstrates that AO 1535 is able to inhibit the production of reactive oxygen intermediates in human monocytes and macrophages stimulated by phorbol ester and chemotactic tetrapeptide, suggesting a potential clinical application of AO 1535 in the treatment of inflammatory dermatoses.

Customer satisfaction and response to AOS

DOT National Transportation Integrated Search

1999-01-01

Passenger surveys were conducted in each of three successive springs in order to track passenger perception of changes in service quality during AOS implementation. In general, no improvement in passenger perceptions was observed relative to a high b...

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.

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.

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.

CfAO Fall Science Retreat 2017

Science.gov Websites

: Mark Chun, Astronomy Dept., U. Hawaii) Point Spread Function Reconstruction for AO Science (Organizer : Jessica Lu, Astronomy Dept., UC Berkeley) High Contrast Exoplanet Instrumentation Program for TMT (Organizer: Michael Fitzgerald, Astronomy Dept., UCLA) Special Plenary Session: TMT international training

VizieR Online Data Catalog: Robo-AO Kepler Planetary Candidate Survey. III. (Ziegler+, 2017)

NASA Astrophysics Data System (ADS)

Ziegler, C.; Law, N. M.; Morton, T.; Baranec, C.; Riddle, R.; Atkinson, D.; Baker, A.; Roberts, S.; Ciardi, D. R.

2018-04-01

KOI targets were selected from the KOI catalog based on Q1-Q17 Kepler data (Borucki et al. 2010ApJ...713L.126B, 2011, J/ApJ/728/117, J/ApJ/736/19; Batalha et al. 2013, J/ApJS/204/24; Burke et al. 2014, J/ApJS/210/19; Rowe et al. 2014, J/ApJ/784/45; Thompson et al. 2015, J/ApJ/812/46). We selected targets not observed in Law et al. 2014ApJ...791...35L and Baranec et al. 2016, J/AJ/152/18, with the objective of completing the Robo-AO survey of all KOIs, including those with already detected companions. We obtained high-angular-resolution images of the 1629 KOIs during 55 separate nights of observations between 2012 July 16 and 2015 June 12 (UT), detailed in Table 9 in the Appendix. The observations were performed using the Robo-AO laser adaptive optics system (Riddle et al. 2012SPIE.8447E..2OR; Baranec et al. 2013JVE....7250021B, 2014ApJ...790L...8B) mounted on the Palomar 1.5 m telescope. (6 data files).

Up-Regulated Expression of AOS-LOXa and Increased Eicosanoid Synthesis in Response to Coral Wounding

PubMed Central

Lõhelaid, Helike; Teder, Tarvi; Tõldsepp, Kadri; Ekins, Merrick; Samel, Nigulas

2014-01-01

In octocorals, a catalase–like allene oxide synthase (AOS) and an 8R-lipoxygenase (LOX) gene are fused together encoding for a single AOS-LOX fusion protein. Although the AOS-LOX pathway is central to the arachidonate metabolism in corals, its biological function in coral homeostasis is unclear. Using an acute incision wound model in the soft coral Capnella imbricata, we here test whether LOX pathway, similar to its role in plants, can contribute to the coral damage response and regeneration. Analysis of metabolites formed from exogenous arachidonate before and after fixed time intervals following wounding indicated a significant increase in AOS-LOX activity in response to mechanical injury. Two AOS-LOX isoforms, AOS-LOXa and AOS-LOXb, were cloned and expressed in bacterial expression system as active fusion proteins. Transcription levels of corresponding genes were measured in normal and stressed coral by qPCR. After wounding, AOS-LOXa was markedly up-regulated in both, the tissue adjacent to the incision and distal parts of a coral colony (with the maximum reached at 1 h and 6 h post wounding, respectively), while AOS-LOXb was stable. According to mRNA expression analysis, combined with detection of eicosanoid product formation for the first time, the AOS-LOX was identified as an early stress response gene which is induced by mechanical injury in coral. PMID:24551239

Novel algorithm implementations in DARC: the Durham AO real-time controller

NASA Astrophysics Data System (ADS)

Basden, Alastair; Bitenc, Urban; Jenkins, David

2016-07-01

The Durham AO Real-time Controller has been used on-sky with the CANARY AO demonstrator instrument since 2010, and is also used to provide control for several AO test-benches, including DRAGON. Over this period, many new real-time algorithms have been developed, implemented and demonstrated, leading to performance improvements for CANARY. Additionally, the computational performance of this real-time system has continued to improve. Here, we provide details about recent updates and changes made to DARC, and the relevance of these updates, including new algorithms, to forthcoming AO systems. We present the computational performance of DARC when used on different hardware platforms, including hardware accelerators, and determine the relevance and potential for ELT scale systems. Recent updates to DARC have included algorithms to handle elongated laser guide star images, including correlation wavefront sensing, with options to automatically update references during AO loop operation. Additionally, sub-aperture masking options have been developed to increase signal to noise ratio when operating with non-symmetrical wavefront sensor images. The development of end-user tools has progressed with new options for configuration and control of the system. New wavefront sensor camera models and DM models have been integrated with the system, increasing the number of possible hardware configurations available, and a fully open-source AO system is now a reality, including drivers necessary for commercial cameras and DMs. The computational performance of DARC makes it suitable for ELT scale systems when implemented on suitable hardware. We present tests made on different hardware platforms, along with the strategies taken to optimise DARC for these systems.

Development of a spectral break in the nonthermal emission of AO 0235+164

NASA Technical Reports Server (NTRS)

Odell, S. L.; Puschell, J. J.; Stein, W. A.; Warner, J. W.

1977-01-01

Results are reported for braod-band photometry of the BL Lac object AO 0235+164 carried out over the spectral range from 0.36 to 3.5 microns in December 1975 and in October and November 1976. It is found that the continuum of this object steepened at visible wavelengths between December 1975 and October 1976, but maintained a relatively constant slope in the near-IR despite a factor-of-ten decrease in flux from the maximum level. Visible-wavelength data are cited which appear to suggest that the steepening of the visible spectrum occurred in less than 300 days, while the near-IR level may have been nearly constant. It is shown that the observed change in the spectral shape of the visible-wavelength continuum cannot be explained in terms of a 'composite' model consisting of an unchanging galaxy and a varying nonthermal source with constant spectral index. Two other general classes of models are considered: intrinsic variability and extrinsic modulation.

ROBO-AO M DWARF MULTIPLICITY SURVEY

NASA Astrophysics Data System (ADS)

Lamman, Claire; Berta-Thompson, Zachory; Baranec, Christoph; Law, Nicholas; Schonhut, Jessica

2018-01-01

We analyzed over 7,000 observations from Robo-AO’s field M dwarf survey taken on the 2.1m Kitt Peak telescope. Results will help determine the multiplicity fraction of M dwarfs as a function of primary mass, which is a crucial step towards understanding their evolution and formation mechanics. Through its robotic, laser-guided, and automated system, the Robo-AO instrument has yielded the largest adaptive-optics M dwarf survey to date. I developed a graphical user interface to quickly analyze this data. Initial data analysis included assessing data quality, checking the result from Robo-AO’s automatic reduction pipeline, and determining existence as well as the relative position of companions through a visual inspection. This program can be applied to other datasets and was successfully tested by re-analyzing observations from a separate Robo-AO survey. Following the preliminary results from this data analysis tool, further observations were done with the Keck II telescope by using its NIRC2 imager to follow up on ten select targets for the existence and physical association of companions. After a conservative initial cut for quality, 356 companions were found within 4” of a primary star out of 2,746 high quality Robo-AO M dwarf observations, including four triple systems. We will present a preliminary estimate for the multiplicity rate of wide M dwarf companions after accounting for observation limitations and the completeness of our search. Future research will yield insights into low-mass stellar formation and provide a database of nearby M dwarf multiples that will potentially assist ongoing and future surveys for planets around these stars, such as the NASA TESS mission.

Cost study : before, during and after AOS implementation (October 1996 - May 1999)

DOT National Transportation Integrated Search

This study compared AATA operating costs over two different time periods: before and during AOS installation. While neither additional operating costs nor operating costs savings were traceable to AOS at this time, the implications of this report, wh...

Discovery of high and very high-energy emission from the BL Lacertae object SHBL J001355.9–185406

DOE PAGES

Abramowski, A.; Acero, F.; Aharonian, F.; ...

2013-06-05

In this paper, the detection of the high-frequency peaked BL Lac object (HBL) SHBL J001355.9–185406 (z = 0.095) at high (HE; 100 MeV < E < 300 GeV) and very high-energy (VHE; E > 100 GeV) with the Fermi Large Area Telescope (LAT) and the High Energy Stereoscopic System (H.E.S.S.) is reported. Dedicated observations were performed with the H.E.S.S. telescopes, leading to a detection at the 5.5σ significance level. The measured flux above 310 GeV is (8.3 ± 1.7 stat ± 1.7 sys) × 10 -13 photons cm -2 s -1 (about 0.6% of that of the Crab Nebula), andmore » the power-law spectrum has a photon index of Γ = 3.4 ± 0.5 stat ± 0.2 sys. Using 3.5 years of publicly available Fermi-LAT data, a faint counterpart has been detected in the LAT data at the 5.5σ significance level, with an integrated flux above 300 MeV of (9.3 ± 3.4 stat ± 0.8 sys) × 10 -10 photons cm -2 s -1 and a photon index of Γ = 1.96 ± 0.20 stat ± 0.08 sys. X-ray observations with Swift-XRT allow the synchrotron peak energy in νF ν representation to be located at ~1.0 keV. The broadband spectral energy distribution is modelled with a one-zone synchrotronself-Compton (SSC) model and the optical data by a black-body emission describing the thermal emission of the host galaxy. Lastly, the derived parameters are typical of HBLs detected at VHE, with a particle-dominated jet.« less

OPERA, an automatic PSF reconstruction software for Shack-Hartmann AO systems: application to Altair

NASA Astrophysics Data System (ADS)

Jolissaint, Laurent; Veran, Jean-Pierre; Marino, Jose

2004-10-01

When doing high angular resolution imaging with adaptive optics (AO), it is of crucial importance to have an accurate knowledge of the point spread function associated with each observation. Applications are numerous: image contrast enhancement by deconvolution, improved photometry and astrometry, as well as real time AO performance evaluation. In this paper, we present our work on automatic PSF reconstruction based on control loop data, acquired simultaneously with the observation. This problem has already been solved for curvature AO systems. To adapt this method to another type of WFS, a specific analytical noise propagation model must be established. For the Shack-Hartmann WFS, we are able to derive a very accurate estimate of the noise on each slope measurement, based on the covariances of the WFS CCD pixel values in the corresponding sub-aperture. These covariances can be either derived off-line from telemetry data, or calculated by the AO computer during the acquisition. We present improved methods to determine 1) r0 from the DM drive commands, which includes an estimation of the outer scale L0 2) the contribution of the high spatial frequency component of the turbulent phase, which is not corrected by the AO system and is scaled by r0. This new method has been implemented in an IDL-based software called OPERA (Performance of Adaptive Optics). We have tested OPERA on Altair, the recently commissioned Gemini-North AO system, and present our preliminary results. We also summarize the AO data required to run OPERA on any other AO system.

VizieR Online Data Catalog: Robo-AO Kepler planetary candidate survey. II. (Baranec+, 2016)

NASA Astrophysics Data System (ADS)

Baranec, C.; Ziegler, C.; Law, N. M.; Morton, T.; Riddle, R.; Atkinson, D.; Schonhut, J.; Crepp, J.

2016-10-01

We selected targets that we had not previously observed from the KOI Catalog based on the Q1-Q12 Kepler data (Rowe et al. 2015, Cat. J/ApJS/217/16). These targets were added to the Robo-AO intelligent observing queue and observed during the summer of 2013. We obtained high angular resolution images of 956 Kepler planet candidate host stars with the Robo-AO robotic laser AOs system over the course of 19 nights between 2013 July 21 and 2013 October 25, detailed in Table5. We also include 13 images from 2012 (2012 July 16-September 13) that required additional confirmation of the KOI position in the Robo-AO field of view. All the observations were performed in a queue-scheduled mode in combination with other science programs using the Robo-AO autonomous laser AO system mounted on the robotic 1.5m telescope at Palomar Observatory (exposure time: 90s; observation wavelengths: 600-950nm; FWHM resolution: 0.12''-0.15''; field of view: 44''*44''; pixel scale: 43.1mas/pix; detector format: 10242 pixels; targets observed/hour: 20). We obtained images of 50 KOIs with the NIRC2 instrument behind the Keck II AO system that were previously observed with Robo-AO and had evidence of a companion. Observations were conducted on 2013 June 25, 2013 August 24 and 25, 2014 August 17, and 2015 July 25 in the K, Ks, or Kp filters, and in the narrow mode of NIRC2 (9.952mas/pixel). (4 data files).

Selected highlights from the Extreme Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Bowyer, S.; Malina, R. F.

1995-01-01

We present a few scientific highlights from the Extreme Ultraviolet Explorer (EUVE) all-sky and deep surveys, from the EUVE Righ Angle Program, and from the EUVE Guest Observer Program. The First EUVE Source Catalog includes 410 extreme ultraviolet (EUV) sources detected in the initial processing of the EUVE all-sky data. A program of optical identification indicates that counterparts include cool star coronae, flare stars, hot white dwarfs, central stars of planetary nebulae, B star photospheres and winds, an X-ray binary, extragalactic objects (active galactic nuclei, BL Lacertae), solar system objects (Moon, Mars, Io,), supernova remnants, and two novae.

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.

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.

Studies of BL Lacertae objects with the Einstein Observatory - The soft X-ray spectra of OJ 287 and PKS 0735+178

NASA Technical Reports Server (NTRS)

Madejski, Greg M.; Schwartz, Daniel A.

1988-01-01

Accurate, soft X-ray spectra of two BL Lac objects, OJ 287 and PKS 0735+178, are presented. The X-ray spectra are well described by a power-law model with a low-energy cutoff consistent with photoelectric absorption within the Galaxy. The best-fit values of the energy spectral index in the 0.2-4.0 keV band are 0.91 and 0.76 respectively. The X-ray flux from OJ 287 is variable by a ratio of three from low to high state; PKS 0735+178 shows no indication of X-ray variability. The X-ray emission in OJ 287 is interpreted to be due to the synchrotron process from a volume common with either a beamed radio component or a stationary optical component. In PKS 0735+178, where the X-ray emission is most likely due to the Compton process operating in one of the VLBI radio components. The synchrotron self-Compton process with modest kinematic Doppler factors predicts the measured X-ray flux from PKS 0735+178 and lower than the measured flux in OJ 287.

Development of Adaptive Tilt Tracker that Utilizes QUAD-cell Detector to Track Extended Objects

DTIC Science & Technology

2014-03-17

telescopes. When incident light encounters the atmosphere , it experiences a turbulent medium that distorts optical wavefronts. Without the AO...fluctuations which randomize optical path lengths. Figure 2 - The temporal and spatial aspects of atmospheric turbulence [6] Consider...the PTS are determined by atmospheric turbulence , optical set-up, and object characteristics such as size, shape, motion, and intensity

Hubble Space Telescope Images and Spectra of Objects Around an Optically Violent Variable QSO

NASA Astrophysics Data System (ADS)

Burbidge, E. M.; Beaver, E. A.; Cohen, R. D.; Hamann, F.; Junkkarinen, V. T.; Lyons, R. W.; Zuo, L.

1995-12-01

The Arecibo Occultation radio source AO 0235+164 is a rapidly and violently variable QSO with ze = 0.94. It was originally designated as a BL Lac object since no emission lines were detected in its spectrum; two absorption redshifts at 0.524 and 0.851 were measured some years before weak emission lines at z = 0.94 were detected by Cohen et al. (ApJ,318,577,1987). A point-like companion (Smith et al., ApJ,218,611,1977) was found 2 arc sec south with an emission line redshift at 0.524. It was designated object A by Yanny et al. (ApJ,338,735,1989). This object has sometimes been called a ``normal'' galaxy, presumably giving rise to the absorption at 0.524 in the QSO. Recent observations of the surrounding field, using the post-repair WFPC 2 on the Hubble Space Telescope, have been analyzed and the nature of the companion object 2 arc sec south, and of a second companion 1.3 arc sec east of AO, have been studied. Spectra of companion object A have been obtained with the Faint Object Spectrograph with gratings G160L and G270H, and 1.0 arc sec aperture, and these show that it is an AGN or QSO with BAL-type broad absorption lines shortward of CIVlambda 1549, SiIVlambda 1397, and NVlambda 1240, also broad CIII]lambda 1909 emission. The second object, A1, 1.3 arc sec east of the QSO, originally identified by Yanny et al. (1989) and shown to have [0II]lambda 3727 at z=0.524, is slightly extended. The physical properties and nature of this remarkable configuration will be discussed. This research has been supported in part by NASA NAS5-29293 and NAG5-1630.

Thin glass shells for AO: from plano to off-axis aspherics

NASA Astrophysics Data System (ADS)

Harel, Emmanuelle; Anretar, Alain; Antelme, Jean-Pierre; Caillon, Stéphane; Dussourd, Adrien; Foucaud, Guillaume; Jaury, Hervé; Roure, Océane; William, Jean-Philippe; Wuillaume, Philippe; Ruch, Eric; Geyl, Roland

2016-07-01

Reosc has been working on thin glass shells for many years and was recently selected by ESO for the production of the E-ELT M4 mirror thin glass shells. Previously Reosc also produced the aspheric thin shell for the VLT-M2 AO Facility. Based on this experience we will discuss how off axis thin glass shells can be made for the next generation AO systems like the GMT one.

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.

Scythe regulates apoptosis through modulating ubiquitin-mediated proteolysis of the Xenopus elongation factor XEF1AO

PubMed Central

Minami, Ryosuke; Shimada, Masumi; Yokosawa, Hideyoshi; Kawahara, Hiroyuki

2007-01-01

Scythe was originally identified as a novel Reaper-binding anti-apoptotic protein, although the mechanisms of its functions remain largely obscure. Our previous analysis revealed that Scythe can bind to a proteasomal subunit via N-terminal domains and that the domains are required for appropriate development of Xenopus embryos. In the present study, we show evidence that the N-terminus of Scythe interacts with XEF1AO, a maternal form of Xenopus laevis EF1A that was suggested to be a potential inducer of apoptosis in vertebrates, and that the binding enhances the poly-ubiquitin modification and subsequent degradation of XEF1AO. Scythe is required for degradation of XEF1AO, since immunodepletion of Scythe from embryonic extracts stabilized XEF1AO significantly. Furthermore, we show that apoptosis induced by accumulation of XEF1AO can be suppressed by co-expression of the full-length form of Scythe. These observations indicate that the proteolytic regulation of XEF1AO, mediated through Scythe, is essential to prevent inappropriate accumulation of XEF1AO and resulting apoptotic events during the course of Xenopus development. PMID:17428197

Initial Performance of the Keck AO Wavefront Controller System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johansson, E M; Acton, D S; An, J R

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 tomore » the controller performance are discussed.« less

Modeling Data Containing Outliers using ARIMA Additive Outlier (ARIMA-AO)

NASA Astrophysics Data System (ADS)

Saleh Ahmar, Ansari; Guritno, Suryo; Abdurakhman; Rahman, Abdul; Awi; Alimuddin; Minggi, Ilham; Arif Tiro, M.; Kasim Aidid, M.; Annas, Suwardi; Utami Sutiksno, Dian; Ahmar, Dewi S.; Ahmar, Kurniawan H.; Abqary Ahmar, A.; Zaki, Ahmad; Abdullah, Dahlan; Rahim, Robbi; Nurdiyanto, Heri; Hidayat, Rahmat; Napitupulu, Darmawan; Simarmata, Janner; Kurniasih, Nuning; Andretti Abdillah, Leon; Pranolo, Andri; Haviluddin; Albra, Wahyudin; Arifin, A. Nurani M.

2018-01-01

The aim this study is discussed on the detection and correction of data containing the additive outlier (AO) on the model ARIMA (p, d, q). The process of detection and correction of data using an iterative procedure popularized by Box, Jenkins, and Reinsel (1994). By using this method we obtained an ARIMA models were fit to the data containing AO, this model is added to the original model of ARIMA coefficients obtained from the iteration process using regression methods. In the simulation data is obtained that the data contained AO initial models are ARIMA (2,0,0) with MSE = 36,780, after the detection and correction of data obtained by the iteration of the model ARIMA (2,0,0) with the coefficients obtained from the regression Zt = 0,106+0,204Z t-1+0,401Z t-2-329X 1(t)+115X 2(t)+35,9X 3(t) and MSE = 19,365. This shows that there is an improvement of forecasting error rate data.

Isolation and Characterization of an Agaro-Oligosaccharide (AO)-Hydrolyzing Bacterium from the Gut Microflora of Chinese Individuals

PubMed Central

Li, Miaomiao; Li, Guangsheng; Zhu, Liying; Yin, Yeshi; Zhao, Xiaoliang; Xiang, Charlie; Yu, Guangli; Wang, Xin

2014-01-01

Agarose (AP) from red algae has a long history as food ingredients in East Asia. Agaro-oligosaccharides (AO) derived from AP have shown potential prebiotic effects. However, the human gut microbes responsible for the degradation of AO and AP have not yet been fully investigated. Here, we reported that AO and AP can be degraded and utilized at various rates by fecal microbiota obtained from different individuals. Bacteroides uniformis L8 isolated from human feces showed a pronounced ability to degrade AO and generate D-galactose as its final end product. PCR-DGGE analysis showed B. uniformis to be common in the fecal samples, but only B. uniformis L8 had the ability to degrade AO. A synergistic strain, here classified as Escherichia coli B2, was also identified because it could utilize the D-galactose as the growth substrate. The cross-feeding interaction between B. uniformis L8 and E. coli B2 led to exhaustion of the AO supply. Bifidobacterium infantis and Bifidobacterium adolescentis can utilize one of the intermediates of AO hydrolysis, agarotriose. Growth curves indicated that AO was the substrate that most favorably sustained the growth of B. uniformis L8. In contrast, κ-carrageenan oligosaccharides (KCO), guluronic acid oligosaccharides (GO), and mannuronic acid oligosaccharides (MO) were found to be unusable to B. uniformis L8. Current results indicate that B. uniformis L8 is a special degrader of AO in the gut microbiota. Because B. uniformis can mitigate high-fat-diet-induced metabolic disorders, further study is required to determine the potential applications of AO. PMID:24622338

Isolation and characterization of an agaro-oligosaccharide (AO)-hydrolyzing bacterium from the gut microflora of Chinese individuals.

PubMed

Li, Miaomiao; Li, Guangsheng; Zhu, Liying; Yin, Yeshi; Zhao, Xiaoliang; Xiang, Charlie; Yu, Guangli; Wang, Xin

2014-01-01

Agarose (AP) from red algae has a long history as food ingredients in East Asia. Agaro-oligosaccharides (AO) derived from AP have shown potential prebiotic effects. However, the human gut microbes responsible for the degradation of AO and AP have not yet been fully investigated. Here, we reported that AO and AP can be degraded and utilized at various rates by fecal microbiota obtained from different individuals. Bacteroides uniformis L8 isolated from human feces showed a pronounced ability to degrade AO and generate D-galactose as its final end product. PCR-DGGE analysis showed B. uniformis to be common in the fecal samples, but only B. uniformis L8 had the ability to degrade AO. A synergistic strain, here classified as Escherichia coli B2, was also identified because it could utilize the D-galactose as the growth substrate. The cross-feeding interaction between B. uniformis L8 and E. coli B2 led to exhaustion of the AO supply. Bifidobacterium infantis and Bifidobacterium adolescentis can utilize one of the intermediates of AO hydrolysis, agarotriose. Growth curves indicated that AO was the substrate that most favorably sustained the growth of B. uniformis L8. In contrast, κ-carrageenan oligosaccharides (KCO), guluronic acid oligosaccharides (GO), and mannuronic acid oligosaccharides (MO) were found to be unusable to B. uniformis L8. Current results indicate that B. uniformis L8 is a special degrader of AO in the gut microbiota. Because B. uniformis can mitigate high-fat-diet-induced metabolic disorders, further study is required to determine the potential applications of AO.

Properties of optically selected BL Lacertae candidates from the SDSS

NASA Astrophysics Data System (ADS)

Kügler, S. D.; Nilsson, K.; Heidt, J.; Esser, J.; Schultz, T.

2014-09-01

Context. Deep optical surveys open the avenue for finding large numbers of BL Lac objects that are hard to identify because they lack the unique properties classifying them as such. While radio or X-ray surveys typically reveal dozens of sources, recent compilations based on optical criteria alone have increased the number of BL Lac candidates considerably. However, these compilations are subject to biases and may contain a substantial number of contaminating sources. Aims: In this paper we extend our analysis of 182 optically selected BL Lac object candidates from the SDSS with respect to an earlier study. The main goal is to determine the number of bona fide BL Lac objects in this sample. Methods: We examine their variability characteristics, determine their broad-band radio-UV spectral energy distributions (SEDs), and search for the presence of a host galaxy. In addition we present new optical spectra for 27 targets with improved signal-to-noise ratio with respect to the SDSS spectra. Results: At least 59% of our targets have shown variability between SDSS DR2 and our observations by more than 0.1-0.27 mag depending on the telescope used. A host galaxy was detected in 36% of our targets. The host galaxy type and luminosities are consistent with earlier studies of BL Lac host galaxies. Simple fits to broad-band SEDs for 104 targets of our sample derived synchrotron peak frequencies between 13.5 ≤ log 10(νpeak) ≤ 16 with a peak at log 10 ~ 14.5. Our new optical spectra do not reveal any new redshift for any of our objects. Thus the sample contains a large number of bona fide BL Lac objects and seems to contain a substantial fraction of intermediate-frequency peaked BL Lacs. Based on observations collected with the NTT on La Silla (Chile) operated by the European Southern Observatory under proposal 082.B-0133.Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA), operated jointly by the Max-Planck-Institut für Astronomie and the

Analysis of Microvariable Activity of BL Lacertae

NASA Astrophysics Data System (ADS)

Sadun, Alberto C.; Asadi-Zeydabadi, Masoud; Hindman, Lauren; Moody, J. Ward

2018-06-01

BL Lac is a low-frequency peaked blazar (LBL) which emits synchrotron radiation at near-IR and optical wavelengths. Therefore optical observations are helpful in, among other things, studying the acceleration and cooling timescales of the electrons in the relativistic jets. We have made very high cadence observations of BL Lac over a number of nights with the Remote Observatory for Variable Object Research (ROVOR). Each night shows secular drift as well as a number of microvariable events lasting only a few minutes each. These data were then processed, compiled, and analyzed in order to examine the underlying mechanism that resulted in such activity. A geometric model is introduced that has worked well in the past on other similar sources.Our relativistic jet model consists of a slowly varying beamed source that already appears bright because it lies nearly to our line of sight. From this, individual relativistic components are ejected a few degrees relative to the aforementioned beaming angle. This is what we believe is responsible for the microvariability emission.

Review of adaptive optics OCT (AO-OCT): principles and applications for retinal imaging [Invited

PubMed Central

Pircher, Michael; Zawadzki, Robert J

2017-01-01

In vivo imaging of the human retina with a resolution that allows visualization of cellular structures has proven to be essential to broaden our knowledge about the physiology of this precious and very complex neural tissue that enables the first steps in vision. Many pathologic changes originate from functional and structural alterations on a cellular scale, long before any degradation in vision can be noted. Therefore, it is important to investigate these tissues with a sufficient level of detail in order to better understand associated disease development or the effects of therapeutic intervention. Optical retinal imaging modalities rely on the optical elements of the eye itself (mainly the cornea and lens) to produce retinal images and are therefore affected by the specific arrangement of these elements and possible imperfections in curvature. Thus, aberrations are introduced to the imaging light and image quality is degraded. To compensate for these aberrations, adaptive optics (AO), a technology initially developed in astronomy, has been utilized. However, the axial sectioning provided by retinal AO-based fundus cameras and scanning laser ophthalmoscope instruments is limited to tens of micrometers because of the rather small available numerical aperture of the eye. To overcome this limitation and thus achieve much higher axial sectioning in the order of 2-5µm, AO has been combined with optical coherence tomography (OCT) into AO-OCT. This enabled for the first time in vivo volumetric retinal imaging with high isotropic resolution. This article summarizes the technical aspects of AO-OCT and provides an overview on its various implementations and some of its clinical applications. In addition, latest developments in the field, such as computational AO-OCT and wavefront sensor less AO-OCT, are covered. PMID:28663890

Review of adaptive optics OCT (AO-OCT): principles and applications for retinal imaging [Invited].

PubMed

Pircher, Michael; Zawadzki, Robert J

2017-05-01

In vivo imaging of the human retina with a resolution that allows visualization of cellular structures has proven to be essential to broaden our knowledge about the physiology of this precious and very complex neural tissue that enables the first steps in vision. Many pathologic changes originate from functional and structural alterations on a cellular scale, long before any degradation in vision can be noted. Therefore, it is important to investigate these tissues with a sufficient level of detail in order to better understand associated disease development or the effects of therapeutic intervention. Optical retinal imaging modalities rely on the optical elements of the eye itself (mainly the cornea and lens) to produce retinal images and are therefore affected by the specific arrangement of these elements and possible imperfections in curvature. Thus, aberrations are introduced to the imaging light and image quality is degraded. To compensate for these aberrations, adaptive optics (AO), a technology initially developed in astronomy, has been utilized. However, the axial sectioning provided by retinal AO-based fundus cameras and scanning laser ophthalmoscope instruments is limited to tens of micrometers because of the rather small available numerical aperture of the eye. To overcome this limitation and thus achieve much higher axial sectioning in the order of 2-5µm, AO has been combined with optical coherence tomography (OCT) into AO-OCT. This enabled for the first time in vivo volumetric retinal imaging with high isotropic resolution. This article summarizes the technical aspects of AO-OCT and provides an overview on its various implementations and some of its clinical applications. In addition, latest developments in the field, such as computational AO-OCT and wavefront sensor less AO-OCT, are covered.

An eight-octant phase-mask coronagraph for the Subaru coronagraphic extreme AO (SCExAO) system: system design and expected performance

NASA Astrophysics Data System (ADS)

Murakami, Naoshi; Guyon, Olivier; Martinache, Frantz; Matsuo, Taro; Yokochi, Kaito; Nishikawa, Jun; Tamura, Motohide; Kurokawa, Takashi; Baba, Naoshi; Vogt, Frédéric; Garrel, Vincent; Yoshikawa, Takashi

2010-07-01

An eight-octant phase-mask (EOPM) coronagraph is one of the highest performance coronagraphic concepts, and attains simultaneously high throughput, small inner working angle, and large discovery space. However, its application to ground-based telescopes such as the Subaru Telescope is challenging due to pupil geometry (thick spider vanes and large central obstruction) and residual tip-tilt errors. We show that the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system, scheduled to be installed onto the Subaru Telescope, includes key technologies which can solve these problems. SCExAO uses a spider removal plate which translates four parts of the pupil with tilted plane parallel plates. The pupil central obstruction can be removed by a pupil remapping system similar to the PIAA optics already in the SCExAO system, which could be redesigned with no amplitude apodization. The EOPM is inserted in the focal plane to divide a stellar image into eight-octant regions, and introduces a π-phase difference between adjacent octants. This causes a self-destructive interference inside the pupil area on a following reimaged pupil plane. By using a reflective mask instead of a conventional opaque Lyot stop, the stellar light diffracted outside the pupil can be used for a coronagraphic low-order wave-front sensor to accurately measure and correct tip-tilt errors. A modified inverse-PIAA system, located behind the reimaged pupil plane, is used to remove off-axis aberrations and deliver a wide field of view. We show that this EOPM coronagraph architecture enables high contrast imaging at small working angle on the Subaru Telescope. Our approach could be generalized to other phase-mask type coronagraphs and other ground-based telescopes.

Asiago spectroscopic classification of ASAS-SN18ao

NASA Astrophysics Data System (ADS)

Tomasella, L.; Benetti, S.; Cappellaro, E.; Turatto, M.

2018-01-01

The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of ASAS-SN18ao (aka AT2018gm, Atel #11178) discovered during the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014).

Monsters in the sky. I mostri del cielo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maffei, P.

1980-01-01

The book treats astronomical objects and phenomena which remain unexplained or unproven by current investigators. Specific objects discussed include comets, satellite clouds surrounding the earth, tektites, the planet Vulcan (within the orbit of Mercury), Planet X (beyond Pluto), the Gum Nebula, planetary nebulae, supernovae, supernova remnants, transient X-ray sources, the possible extinction of the dinosaurs by an X-ray explosion and super-supernovae. Attention is also given to the star Eta Carinae, black holes, BL Lacertae objects, active galaxies, Markarian galaxies, N and compact galaxies, Seyfert galaxies, quasars, redshift anomalies, Stephan's quintet of galaxies, and intergalactic black holes or black dwarfs whichmore » may account for the mass necessary to bind together clusters of galaxies.« less

Empirical multi-wavelength prediction method for very high energy gamma-ray emitting BL Lacertae objects

NASA Astrophysics Data System (ADS)

Fallah Ramazani, V.; Lindfors, E.; Nilsson, K.

2017-12-01

Aim: We have collected the most complete multi-wavelength (6.0-6.0 × 10-18 cm) dataset of very high energy (VHE) γ-ray emitting (TeV) BL Lacs, which are the most numerous extragalactic VHE sources. Using significant correlations between different bands, we aim to identify the best TeV BL Lac candidates that can be discovered by the current and next generation of imaging air Cherenkov telescopes. Methods: We formed five datasets from lower energy data, i.e. radio, mid-infrared, optical, X-rays, and GeV γ-ray, and five VHE γ-ray datasets to perform a correlation study between different bands and to construct the prediction method. The low energy datasets were averaged for individual sources, while the VHE γ-ray data were divided into subsets according to the flux state of the source. We then looked for significant correlations and determined their best-fit parameters. Using the best-fit parameters we predicted the level of VHE γ-ray flux for a sample of 182 BL Lacs, which have not been detected at TeV energies. We identified the most promising TeV BL Lac candidates based on the predicted VHE γ-ray flux for each source. Results: We found 14 significant correlations between radio, mid-infrared, optical, γ-ray, and VHE γ-ray bands. The correlation between optical and VHE γ-ray luminosity is established for the first time. We attribute this to the more complete sample and more accurate handling of host galaxy flux in our work. We found nine BL Lac candidates whose predicted VHE γ-ray flux is high enough for detection in less than 25 h with current imaging air Cherenkov telescopes. Full Tables A.1 and A.2 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A68

Probing circumplanetary disks with MagAO and ALMA

NASA Astrophysics Data System (ADS)

Wu, Ya-Lin

2018-01-01

The dedication of the Magellan Adaptive Optics (MagAO) on the 6.5 m Clay Telescope has opened a new era in high-contrast imaging. Its unique diffraction-limited wavelengths of 0.6 to 1 micron helps to probe circumplanetary disks by measuring the amount of dust reddening as well as by searching for the strongest gas accretion indicator H-alpha (0.65 micron). Using MagAO, I found that two wide-orbit planetary-mass companions CT Cha B and 1RXS 1609 B have a significant dust extinction of Av ~ 3 to 5 mag likely from their disks. For GQ Lup B, I found that it is actively accreting material from its disk and emitting strong H-alpha emission. My research with MagAO demonstrates that circumplanetary disks could be ubiquitous among young giant planets. I later carried out a survey using ALMA to image accretion disks around several wide planet-mass companions at 1.3 mm continuum and CO (2-1). This is the first systematic study aiming to measure the size, mass, and structure of planetary disks. However, except for FW Tau C (which was shown to actually be a low-mass star from the dynamical mass measurement) no disks around the companions were found in my ALMA survey. This surprising null result implies that circumplanetary disks are much more compact and denser than expected, so they are faint and optically thick in the radio wavelengths. Therefore, mid- to far-infrared may be more favorable to characterize disk properties. The MIRI camera on the JWST can test this compact optically-thick disk hypothesis by probing disk thermal emission between 10 and 25 micron.

Bridging FPGA and GPU technologies for AO real-time control

NASA Astrophysics Data System (ADS)

Perret, Denis; Lainé, Maxime; Bernard, Julien; Gratadour, Damien; Sevin, Arnaud

2016-07-01

Our team has developed a common environment for high performance simulations and real-time control of AO systems based on the use of Graphics Processors Units in the context of the COMPASS project. Such a solution, based on the ability of the real time core in the simulation to provide adequate computing performance, limits the cost of developing AO RTC systems and makes them more scalable. A code developed and validated in the context of the simulation may be injected directly into the system and tested on sky. Furthermore, the use of relatively low cost components also offers significant advantages for the system hardware platform. However, the use of GPUs in an AO loop comes with drawbacks: the traditional way of offloading computation from CPU to GPUs - involving multiple copies and unacceptable overhead in kernel launching - is not well suited in a real time context. This last application requires the implementation of a solution enabling direct memory access (DMA) to the GPU memory from a third party device, bypassing the operating system. This allows this device to communicate directly with the real-time core of the simulation feeding it with the WFS camera pixel stream. We show that DMA between a custom FPGA-based frame-grabber and a computation unit (GPU, FPGA, or Coprocessor such as Xeon-phi) across PCIe allows us to get latencies compatible with what will be needed on ELTs. As a fine-grained synchronization mechanism is not yet made available by GPU vendors, we propose the use of memory polling to avoid interrupts handling and involvement of a CPU. Network and Vision protocols are handled by the FPGA-based Network Interface Card (NIC). We present the results we obtained on a complete AO loop using camera and deformable mirror simulators.

Extragalactic counterparts to Einstein slew survey sources

NASA Technical Reports Server (NTRS)

Schachter, Jonathan F.; Elvis, Martin; Plummer, David; Remillard, Ron

1992-01-01

The Einstein slew survey consists of 819 bright X-ray sources, of which 636 (or 78 percent) are identified with counterparts in standard catalogs. The importance of bright X-ray surveys is stressed, and the slew survey is compared to the Rosat all sky survey. Statistical techniques for minimizing confusion in arcminute error circles in digitized data are discussed. The 238 slew survey active galactic nuclei, clusters, and BL Lacertae objects identified to date and their implications for logN-logS and source evolution studies are described.

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.

Intelligent vibration control of ELTs and large AO hardware

NASA Astrophysics Data System (ADS)

Pott, J.-U.; Kürster, M.; Trowitzsch, J.; Borelli, J.; Rohloff, R.-R.; Herbst, T.; Böhm, M.; Keck, A.; Ruppel, T.; Sawodny, O.

2012-07-01

MPIA leads the construction of the LINC-NIRVANA instrument, the MCAO-supported Fizeau imager for the LBT, serves as pathfinder for future ELT-AO imagers in terms of size and technology. In this contribution, we review recent results and significant progress made on the development of key items of our stratgey to achieve a piston stability of up to 100nm during a science exposure. We present an overview of our vibration control strategies for optical path and tip-tilt stabilization, involving accelerometer based real-time vibration measurements, vibration sensitive active control of actuators, and the development of a dynamical model of the LBT. MPIA also co-develops the E-ELT first-light NIR imager MICADO (both SCAO and MCAO assisted). Our experiences, made with LINC-NIRVANA, will be fed into the MICADO structural AO design to reach highest on-sky sensitivity.

Functional analysis of AoAtg11 in selective autophagy in the filamentous fungus Aspergillus oryzae.

PubMed

Tadokoro, Takayuki; Kikuma, Takashi; Kitamoto, Katsuhiko

2015-07-01

Autophagy is a highly conserved cellular degradation process in eukaryotes and consists of both non-selective and selective types. Selective autophagic processes include pexophagy, mitophagy, and the cytoplasm-to-vacuole targeting (Cvt) pathway of yeast, in which particular vacuolar proteins, such as aminopeptidase I (Ape1), are selectively transported to vacuoles. Although selective autophagy has been mainly studied in the yeasts Saccharomyces cerevisiae and Pichia pastoris, there is evidence for selective autophagy in filamentous fungi; however, the details are poorly understood. In S. cerevisiae, Atg11 is a selective autophagy-specific protein that recognizes and transports substrates to the pre-autophagosomal structure (PAS). Here, we first identified an ATG11 homologue in the filamentous fungus Aspergillus oryzae and analyzed the localization of the corresponding protein, designated AoAtg11, fused to enhanced green fluorescent protein (EGFP). Imaging analysis revealed that AoAtg11-EGFP was localized to PAS-like structures. We next constructed an Aoatg11 disruptant of A. oryzae and showed that AoAtg11 is involved in pexophagy and mitophagy. In addition, AoAtg11 was found to be dispensable for non-selective autophagy and for transporting AoApe1 to vacuoles. Taken together, these results suggest that AoAtg11 is a selective autophagy-specific protein in A. oryzae, and has distinct molecular functions from that of S. cerevisiae Atg11. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Analysis of Alternatives (AoA) Process Improvement Study

DTIC Science & Technology

2016-12-01

stakeholders, and mapped the process activities and durations. We tasked the SAG members with providing the information required on case studies and...are the expected time saves/cost/risk of any changes? (3) Utilization of case studies for both “good” and “challenged” AoAs to identify lessons...16 4 CASE STUDIES

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

2014-10-29

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

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.

Early Direct Imaging and Spectral Characterization of Extrasolar Planets with the SCExAO/CHARIS

NASA Astrophysics Data System (ADS)

Currie, Thayne; Guyon, Olivier; Kasdin, Jeremy; Brandt, Timothy; Groff, Tyler; Jovanovic, Nemanja; Lozi, Julien; Chilcote, Jeffrey K.; Uyama, Taichi; Ascensio-Torres, Ruben; Tamura, Motohide; Norris, Barnaby

2018-01-01

We present selected direct imaging/spectroscopy results from Subaru’s extreme adaptive optics system, SCExAO, coupled with the CHARIS integral field spectrograph obtained from the first full year of CHARIS’s operation. SCExAO/CHARIS yields high signal-to-noise detections and 1.1—2.4 micron spectra of benchmark directly-imaged companions like HR 8799 cde and kappa And b that clarify their atmospheric properties. We describe these results and multi-epoch, multi-wavelength imaging of LkCa 15 to assess the (non-)existence of protoplanetary companions, and briefly describe upgrades to SCExAO that will allow it to image and characterize even fainter self-luminous extrasolar planets and eventually mature planets in reflected light.

Genes regulated by AoXlnR, the xylanolytic and cellulolytic transcriptional regulator, in Aspergillus oryzae.

PubMed

Noguchi, Yuji; Sano, Motoaki; Kanamaru, Kyoko; Ko, Taro; Takeuchi, Michio; Kato, Masashi; Kobayashi, Tetsuo

2009-11-01

XlnR is a Zn(II)2Cys6 transcriptional activator of xylanolytic and cellulolytic genes in Aspergillus. Overexpression of the aoxlnR gene in Aspergillus oryzae (A. oryzae xlnR gene) resulted in elevated xylanolytic and cellulolytic activities in the culture supernatant, in which nearly 40 secreted proteins were detected by two-dimensional electrophoresis. DNA microarray analysis to identify the transcriptional targets of AoXlnR led to the identification of 75 genes that showed more than fivefold increase in their expression in the AoXlnR overproducer than in the disruptant. Of these, 32 genes were predicted to encode a glycoside hydrolase, highlighting the biotechnological importance of AoXlnR in biomass degradation. The 75 genes included the genes previously identified as AoXlnR targets (xynF1, xynF3, xynG2, xylA, celA, celB, celC, and celD). Thirty-six genes were predicted to be extracellular, which was consistent with the number of proteins secreted, and 61 genes possessed putative XlnR-binding sites (5'-GGCTAA-3', 5'-GGCTAG-3', and 5'-GGCTGA-3') in their promoter regions. Functional annotation of the genes revealed that AoXlnR regulated the expression of hydrolytic genes for degradation of beta-1,4-xylan, arabinoxylan, cellulose, and xyloglucan and of catabolic genes for the conversion of D-xylose to xylulose-5-phosphate. In addition, genes encoding glucose-6-phosphate 1-dehydrogenase and L-arabinitol-4- dehydrogenase involved in D-glucose and L-arabinose catabolism also appeared to be targets of AoXlnR.

CLASSICAL AREAS OF PHENOMENOLOGY: Correcting dynamic residual aberrations of conformal optical systems using AO technology

NASA Astrophysics Data System (ADS)

Li, Yan; Li, Lin; Huang, Yi-Fan; Du, Bao-Lin

2009-07-01

This paper analyses the dynamic residual aberrations of a conformal optical system and introduces adaptive optics (AO) correction technology to this system. The image sharpening AO system is chosen as the correction scheme. Communication between MATLAB and Code V is established via ActiveX technique in computer simulation. The SPGD algorithm is operated at seven zoom positions to calculate the optimized surface shape of the deformable mirror. After comparison of performance of the corrected system with the baseline system, AO technology is proved to be a good way of correcting the dynamic residual aberration in conformal optical design.

Polarimetry of optically selected BL Lacertae candidates from the SDSS

NASA Astrophysics Data System (ADS)

Heidt, J.; Nilsson, K.

2011-05-01

We present and discuss polarimetric observations of 182 targets drawn from an optically selected sample of 240 probable BL Lac candidates out of the SDSS compiled by Collinge et al. (2005, AJ, 129, 2542). In contrast to most other BL Lac candidate samples extracted from the SDSS, its radio- and/or X-ray properties have not been taken into account for its derivation. Thus, because its selection is based on optical properties alone, it may be less prone to selection effects inherent in other samples derived at different frequencies, so it offers a unique opportunity to extract the first unbiased BL Lac luminosity function that is suitably large in size. We found 124 out of 182 targets (68%) to be polarized, 95 of the polarized targets (77%) to be highly polarized (>4%). The low-frequency peaked BL Lac candidates in the sample are on average only slightly more polarized than the high-frequency peaked ones. Compared to earlier studies, we found a high duty cycle in high polarization (˜ 66+2-14% to be >4% polarized) in high-frequency peaked BL Lac candidates. This may come from our polarization analysis, which minimizes the contamination by host galaxy light. No evidence of radio-quiet BL Lac objects in the sample was found. Our observations show that the probable sample of BL Lac candidates of Collinge et al. (2005) indeed contains a large number of bona fide BL Lac objects. High S/N spectroscopy and deep X-ray observations are required to construct the first luminosity function of optically selected BL Lac objects and to test more stringently for any radio-quiet BL Lac objects in the sample. Based on observations collected with the NTT on La Silla (Chile) operated by the European Southern Observatory in the course of the observing proposal 082.B-0133.Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA), operated jointly by the Max-Planck-Institut für Astronomie and the Instituto de Astrofisica de Andalucia (CSIC).Based on observations

Te Ao Kori as Expressive Movement in Aotearoa New Zealand Physical Education Teacher Education (PETE): A Narrative Account

ERIC Educational Resources Information Center

Legge, Maureen

2011-01-01

A unique aspect of Aotearoa/New Zealand physical education is the inclusion of Maori culture in the form of te ao kori. Te ao kori translates to mean the world of movement and is represented by the interpretation of indigenous movement, games and pastimes. Participation in te ao kori means the sports-based normative frame of reference for physical…

Green FLASH: energy efficient real-time control for AO

NASA Astrophysics Data System (ADS)

Gratadour, D.; Dipper, N.; Biasi, R.; Deneux, H.; Bernard, J.; Brule, J.; Dembet, R.; Doucet, N.; Ferreira, F.; Gendron, E.; Laine, M.; Perret, D.; Rousset, G.; Sevin, A.; Bitenc, U.; Geng, D.; Younger, E.; Andrighettoni, M.; Angerer, G.; Patauner, C.; Pescoller, D.; Porta, F.; Dufourcq, G.; Flaischer, A.; Leclere, J.-B.; Nai, A.; Palazzari, P.; Pretet, D.; Rouaud, C.

2016-07-01

The main goal of Green Flash is to design and build a prototype for a Real-Time Controller (RTC) targeting the European Extremely Large Telescope (E-ELT) Adaptive Optics (AO) instrumentation. The E-ELT is a 39m diameter telescope to see first light in the early 2020s. To build this critical component of the telescope operations, the astronomical community is facing technical challenges, emerging from the combination of high data transfer bandwidth, low latency and high throughput requirements, similar to the identified critical barriers on the road to Exascale. With Green Flash, we will propose technical solutions, assess these enabling technologies through prototyping and assemble a full scale demonstrator to be validated with a simulator and tested on sky. With this R&D program we aim at feeding the E-ELT AO systems preliminary design studies, led by the selected first-light instruments consortia, with technological validations supporting the designs of their RTC modules. Our strategy is based on a strong interaction between academic and industrial partners. Components specifications and system requirements are derived from the AO application. Industrial partners lead the development of enabling technologies aiming at innovative tailored solutions with potential wide application range. The academic partners provide the missing links in the ecosystem, targeting their application with mainstream solutions. This increases both the value and market opportunities of the developed products. A prototype harboring all the features is used to assess the performance. It also provides the proof of concept for a resilient modular solution to equip a large scale European scientific facility, while containing the development cost by providing opportunities for return on investment.

Determination and Application of Training Objectives in Revising the Supplyman (MOS 76A10) Course.

DTIC Science & Technology

1970-08-01

7 AD-AO81 050 HUMAN RESOURCES RESEARCH ORGANIZATION ALEXANDRIA VA G ’/9 DETERMINATION AND APPLICATION OF TRAINING OBJECTIVES IN REVISIN--EC(U) AUG 70...Organization (HumRRO) is a nonprofit corporation established in 1969 to conduct research in the field of training and education. It was established as a con...tinuation of The George Washington University, Human Resources Research Office. HumRRO’s general purpose is to improve human performance

A possible cause of the AO polarity reversal from winter to summer in 2010 and its relation to hemispheric extreme summer weather

NASA Astrophysics Data System (ADS)

Otomi, Yuriko; Tachibana, Yoshihiro; Nakamura, Tetsu

2013-04-01

In 2010, the Northern Hemisphere, in particular Russia and Japan, experienced an abnormally hot summer characterized by record-breaking warm temperatures and associated with a strongly positive Arctic Oscillation (AO), that is, low pressure in the Arctic and high pressure in the midlatitudes. In contrast, the AO index the previous winter and spring (2009/2010) was record-breaking negative. The AO polarity reversal that began in summer 2010 can explain the abnormally hot summer. The winter sea surface temperatures (SST) in the North Atlantic Ocean showed a tripolar anomaly pattern—warm SST anomalies over the tropics and high latitudes and cold SST anomalies over the midlatitudes—under the influence of the negative AO. The warm SST anomalies continued into summer 2010 because of the large oceanic heat capacity. A model simulation strongly suggested that the AO-related summertime North Atlantic oceanic warm temperature anomalies remotely caused blocking highs to form over Europe, which amplified the positive summertime AO. Thus, a possible cause of the AO polarity reversal might be the "memory" of the negative winter AO in the North Atlantic Ocean, suggesting an interseasonal linkage of the AO in which the oceanic memory of a wintertime negative AO induces a positive AO in the following summer. Understanding of this interseasonal linkage may aid in the long-term prediction of such abnormal summer events.

A possible cause of the AO polarity reversal from winter to summer in 2010 and its relation to hemispheric extreme hot summer

NASA Astrophysics Data System (ADS)

Tachibana, Yoshihiro; Otomi, Yuriko; Nakamura, Tetsu

2013-04-01

In 2010, the Northern Hemisphere, in particular Russia and Japan, experienced an abnormally hot summer characterized by record-breaking warm temperatures and associated with a strongly positive Arctic Oscillation (AO), that is, low pressure in the Arctic and high pressure in the midlatitudes. In contrast, the AO index the previous winter and spring (2009/2010) was record-breaking negative. The AO polarity reversal that began in summer 2010 can explain the abnormally hot summer. The winter sea surface temperatures (SST) in the North Atlantic Ocean showed a tripolar anomaly pattern—warm SST anomalies over the tropics and high latitudes and cold SST anomalies over the midlatitudes—under the influence of the negative AO. The warm SST anomalies continued into summer 2010 because of the large oceanic heat capacity. A model simulation strongly suggested that the AO-related summertime North Atlantic oceanic warm temperature anomalies remotely caused blocking highs to form over Europe, which amplified the positive summertime AO. Thus, a possible cause of the AO polarity reversal might be the "memory" of the negative winter AO in the North Atlantic Ocean, suggesting an interseasonal linkage of the AO in which the oceanic memory of a wintertime negative AO induces a positive AO in the following summer. Understanding of this interseasonal linkage may aid in the long-term prediction of such abnormal summer events.

Status and Plans for Finalization of SRT's Contribution to AIRS Version-7 and Version-7 AO

NASA Technical Reports Server (NTRS)

Susskind, Joel; Blaisdell, John; Iredell, Lena; Kouvaris, Louis C.

2017-01-01

Version-6.46 temperature profiles, water vapor profiles, and especially total O3, are very much compared to Version-6. With minor tweaking, Version-6.46 is a good candidate for use in Version-7. JPL Version-6.4.6 and Version-6.4.6 AO monthly mean products agree extremely well with each other. Version-6.4.6 AO is accurate enough that there is not necessarily a need to process both Version-7 and Version-7 AO data sets. Single day comparisons show Version-6.46 CrIS/ATMS and Version-6.46 AIRS/AMSU products agree extremely well with each other. We need to demonstrate agreement of Version-6.46 CrIS/ATMS and Version-6.46 AO products on a monthly mean basis for different months and years. CrIS/ATMS and AIRS/AMSU monthly mean comparisons showed excellent agreement using a previous version.

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

Diferentes Metodologias Aplicadas ao Ensino de Astronomia

NASA Astrophysics Data System (ADS)

Albrecht, E.; Voelzke, M. R.

2007-08-01

Espera-se que o educando ao final da educação básica, adquira uma compreensão atualizada das hipóteses, modelos e formas de investigação sobre a origem e evolução do Universo em que vive. O presente trabalho tem como principal objetivo compreender dentre três práticas pedagógicas adotadas no Ensino de Astronomia, na terceira série do Ensino Médio, da Escola Estadual Colônia dos Pescadores, qual melhor cumpre o papel de formação e aprendizagem para vida. A pesquisa preliminar foi através de um questionário onde o intuito foi diagnosticar o conhecimento já existente acerca do tema em questão. O questionário é composto de vinte questões dissertativas e objetivas, onde os educandos das três turmas envolvidas o responderam. Este trabalho utiliza as seguintes metodologias: a tradicional, onde o professor é um repassador de informações, fazendo uso exclusivo de lousa e giz; a segunda também de forma tradicional, porém com auxílio de multimídia para desenvolvimento das aulas e aterceira sob forma de seminários, elaborados e apresentados pelos educandos, no qual o educador faz apenas as intervenções necessárias. Ao final do trabalho os alunos responderão novamente o questionário inicial para diagnosticar dentre as três metodologias utilizadas qual apresentou melhor resultado. Os resultados preliminares obtidos, já podem ser observados e, dos 119 alunos entrevistados, as respostas obtidas são as mais diversas e evidenciam que a grande maioria nunca teve em sua vida escolar o tema Astronomia. Ao serem questionados se já haviam estudado Astronomia as respostas foram: turma A: sim 43%; turma B: sim: 21%; turma C: sim: 24%. Porém quando questionados a respeito do significado de Astronomia observou-se que: turma A: 100% de acertos; turma B: 64% acertos; turma C: 84% de acertos, demonstrando claramente a aprendizagem em diferentes esferas, não dependendo unicamente da escola. Até o presente momento, verificou-se que há interesse em

Roma-BZCAT: a multifrequency catalogue of blazars

NASA Astrophysics Data System (ADS)

Massaro, E.; Giommi, P.; Leto, C.; Marchegiani, P.; Maselli, A.; Perri, M.; Piranomonte, S.; Sclavi, S.

2009-02-01

We present a new catalogue of blazars based on multifrequency surveys and on an extensive review of the literature. Blazars are classified as BL Lacertae objects, as flat spectrum radio quasars or as blazars of uncertain/transitional type. Each object is identified by a root name, coded as BZB, BZQ and BZU for these three subclasses respectively, and by its coordinates. This catalogue is being built as a tool useful for the identification of the extragalactic sources that will be detected by present and future experiments for X and gamma-ray astronomy, like Swift, AGILE, Fermi-GLAST and Simbol-X. An electronic version is available from the ASI Science Data Center web site at http://www.asdc.asi.it/bzcat.

Discovery of VHE γ-ray emission and multi-wavelength observations of the BL Lacertae object 1RXS J101015.9-311909

NASA Astrophysics Data System (ADS)

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

2012-06-01

1RXS J101015.9-311909 is a galaxy located at a redshift of z=0.14 hosting an active nucleus (called AGN) belonging to the class of bright BL Lac objects. Observations at high (HE, E > 100 MeV) and very high (VHE, E > 100 GeV) energies provide insights into the origin of very energetic particles present in such sources and the radiation processes at work. We report on results from VHE observations performed between 2006 and 2010 with the H.E.S.S. instrument, an array of four imaging atmospheric Cherenkov telescopes. H.E.S.S. data have been analysed with enhanced analysis methods, making the detection of faint sources more significant. VHE emission at a position coincident with 1RXS J101015.9-311909 is detected with H.E.S.S. for the first time. In a total good-quality livetime of about 49 h, we measure 263 excess counts, corresponding to a significance of 7.1 standard deviations. The photon spectrum above 0.2 TeV can be described by a power-law with a photon index of Γ = 3.08 ± 0.42stat ± 0.20sys. The integral flux above 0.2 TeV is about 0.8% of the flux of the Crab nebula and shows no significant variability over the time reported. In addition, public Fermi/LAT data are analysed to search for high energy emission from the source. The Fermi/LAT HE emission in the 100 MeV to 200 GeV energy range is significant at 8.3 standard deviations in the chosen 25-month dataset. UV and X-ray contemporaneous observations with the Swift satellite in May 2007 are also reported, together with optical observations performed with the atom telescope located at the H.E.S.S. site. Swift observations reveal an absorbed X-ray flux of F(0.3-7) keV = 1.04+0.04-0.05 × 10-11 erg cm-2 s-1 in the 0.3-7 keV range. Finally, all the available data are used to study the multi-wavelength properties of the source. The spectral energy distribution (SED) can be reproduced using a simple one-zone Synchrotron Self Compton (SSC) model with emission from a region with a Doppler factor of 30 and a

AO corrected satellite imaging from Mount Stromlo

NASA Astrophysics Data System (ADS)

Bennet, F.; Rigaut, F.; Price, I.; Herrald, N.; Ritchie, I.; Smith, C.

2016-07-01

The Research School of Astronomy and Astrophysics have been developing adaptive optics systems for space situational awareness. As part of this program we have developed satellite imaging using compact adaptive optics systems for small (1-2 m) telescopes such as those operated by Electro Optic Systems (EOS) from the Mount Stromlo Observatory. We have focused on making compact, simple, and high performance AO systems using modern high stroke high speed deformable mirrors and EMCCD cameras. We are able to track satellites down to magnitude 10 with a Strehl in excess of 20% in median seeing.

The AOLI Non-Linear Curvature Wavefront Sensor: High sensitivity reconstruction for low-order AO

NASA Astrophysics Data System (ADS)

Crass, Jonathan; King, David; Mackay, Craig

2013-12-01

Many adaptive optics (AO) systems in use today require bright reference objects to determine the effects of atmospheric distortions on incoming wavefronts. This requirement is because Shack Hartmann wavefront sensors (SHWFS) distribute incoming light from reference objects into a large number of sub-apertures. Bright natural reference objects occur infrequently across the sky leading to the use of laser guide stars which add complexity to wavefront measurement systems. The non-linear curvature wavefront sensor as described by Guyon et al. has been shown to offer a significant increase in sensitivity when compared to a SHWFS. This facilitates much greater sky coverage using natural guide stars alone. This paper describes the current status of the non-linear curvature wavefront sensor being developed as part of an adaptive optics system for the Adaptive Optics Lucky Imager (AOLI) project. The sensor comprises two photon-counting EMCCD detectors from E2V Technologies, recording intensity at four near-pupil planes. These images are used with a reconstruction algorithm to determine the phase correction to be applied by an ALPAO 241-element deformable mirror. The overall system is intended to provide low-order correction for a Lucky Imaging based multi CCD imaging camera. We present the current optical design of the instrument including methods to minimise inherent optical effects, principally chromaticity. Wavefront reconstruction methods are discussed and strategies for their optimisation to run at the required real-time speeds are introduced. Finally, we discuss laboratory work with a demonstrator setup of the system.

Simulated Guide Stars: Adapting the Robo-AO Telescope Simulator to UH 88”

NASA Astrophysics Data System (ADS)

Ashcraft, Jaren; Baranec, Christoph

2018-01-01

Robo-AO is an autonomous adaptive optics system that is in development for the UH 88” Telescope on the Mauna Kea Observatory. This system is capable of achieving near diffraction limited imaging for astronomical telescopes, and has seen successful deployment and use at the Palomar and Kitt Peak Observatories previously. A key component of this system, the telescope simulator, will be adapted from the Palomar Observatory design to fit the UH 88” Telescope. The telescope simulator will simulate the exit pupil of the UH 88” telescope so that the greater Robo-AO system can be calibrated before observing runs. The system was designed in Code V, and then further improved upon in Zemax for later development. Alternate design forms were explored for the potential of adapting the telescope simulator to the NASA Infrared Telescope Facility, where simulating the exit pupil of the telescope proved to be more problematic. A proposed design composed of solely catalog optics was successfully produced for both telescopes, and they await assembly as time comes to construct the new Robo-AO system.

A possible cause of the AO polarity reversal from winter to summer in 2010 and its relation to hemispheric extreme summer weather

NASA Astrophysics Data System (ADS)

Otomi, Y.; Tachibana, Y.; Nakamura, T.

2012-12-01

In 2010, the Northern Hemisphere, in particular Russia, Europe and Japan, experienced an abnormally hot summer characterized by record-breaking warm temperatures and associated with a strongly positive Arctic Oscillation (AO). In contrast, in winter 2009/2010, the continent suffered from anomalously cold weather associated with a record-breaking negative AO. The winter-to-summer of the AO index during 2009/2010 evolved as follows: a strongly negative wintertime AO index continued until May, after which it abruptly changed, becoming strongly positive in July and continuing so until the beginning of August. The abrupt change of the AO index from strongly negative to strongly positive in 2010 thus corresponded to the change from the abnormally cold winter of 2009/2010 to the abnormally hot summer of 2010, which shows that the AO index is a good indicator of abnormal weather on a planetary-scale, and that extra-seasonal prediction of the AO is a key to long-term forecasting. In this study, we therefore aimed to examine the cause of the 2010 change in the AO index from strongly negative to strongly positive. We suggest that an oceanic memory of the strongly negative wintertime AO may have influenced the strongly positive summertime AO. The winter sea surface temperatures (SST) in the North Atlantic Ocean showed a tripolar anomaly pattern which is warm SST anomalies over the tropics and high latitudes and cold SST anomalies over the midlatitudes. The strongly negative wintertime AO would cause the warm SST anomaly in this region. The warm SST anomalies continued into summer 2010 because of the large oceanic heat capacity. In May and June, the heat flux anomaly changed from downward to upward in the tropics, and in July and August, the center of the upward anomaly moved westward. The area of the upward heat flux anomaly coincided with the area of the warm SST anomaly from May to August. The numerical model experiment showed that the tripolar SST pattern resulted in an

FPGA cluster for high-performance AO real-time control system

NASA Astrophysics Data System (ADS)

Geng, Deli; Goodsell, Stephen J.; Basden, Alastair G.; Dipper, Nigel A.; Myers, Richard M.; Saunter, Chris D.

2006-06-01

Whilst the high throughput and low latency requirements for the next generation AO real-time control systems have posed a significant challenge to von Neumann architecture processor systems, the Field Programmable Gate Array (FPGA) has emerged as a long term solution with high performance on throughput and excellent predictability on latency. Moreover, FPGA devices have highly capable programmable interfacing, which lead to more highly integrated system. Nevertheless, a single FPGA is still not enough: multiple FPGA devices need to be clustered to perform the required subaperture processing and the reconstruction computation. In an AO real-time control system, the memory bandwidth is often the bottleneck of the system, simply because a vast amount of supporting data, e.g. pixel calibration maps and the reconstruction matrix, need to be accessed within a short period. The cluster, as a general computing architecture, has excellent scalability in processing throughput, memory bandwidth, memory capacity, and communication bandwidth. Problems, such as task distribution, node communication, system verification, are discussed.

Comparative analysis of the main bioactive components of San-ao decoction and its series of formulations.

PubMed

Shu, Xiaoyun; Tang, Yuping; Jiang, Chenxue; Shang, Erxing; Fan, Xinshen; Ding, Anwei

2012-11-01

A high performance liquid chromatographic (HPLC) method with diode array detection (DAD) was established for simultaneous determination of seven main bioactive components in San-ao decoction and its series of formulae (San-ao decoction, Wu-ao decoction, Qi-ao decoction and Jia-wei San-ao decoction). Seven compounds were analyzed simultaneously with a XTerra C(18) column (4.6 mm × 250 mm, 5 µm) using a linear gradient elution of a mobile phase containing acetonitrile (A) and a buffer solution (0.02 mol/L potassium dihydrogen phosphate and adjusted to pH 3 using phosphoric acid) (B); the flow rate was 1.0 mL/min. The sample was detected with DAD at 210, 254 and 360 nm and the column was maintained at 30 °C. All the compounds showed good linearity (r2 > 0.9984) in the tested concentration range. The precisions were evaluated by intra-day and inter-day tests, and relative standard deviation (R.S.D.) values within the range of 0.83%–2.53% and 0.64%–2.77% were reported, respectively. The recoveries of the quantified compounds were observed to cover a range from 95.34% and 104.82% with R.S.D. values less than 2.72%. The validated method was successfully applied for the simultaneous determination of seven main bioactive components including ephedrine (1), amygdalin (2), liquiritin (3), benzoic acid (4), isoliquiritin (5), formononetin (6) and glycyrrhizic acid (7) in San-ao decoction and its series of formulae. The results also showed a wide variation in the content of the identified active compounds in these samples, which could also be helpful to illustrate the drug interactions after some herbs combined in different formulations.

Optical Properties of High Area-to-Mass Objects at GEO

NASA Technical Reports Server (NTRS)

Seitzer, Patrick; Schildknecht, Thomas; Musci, Reto; Flohrer, Tim; Barker, Ed; Stansbery, Eugene; Agapov, Vladimir; Rumyantsev, Vasilij; Biryukov, Vadym; Abercromby, Kira;

Aspergillus oryzae AoSO is a novel component of stress granules upon heat stress in filamentous fungi.

PubMed

Huang, Hsiang-Ting; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

2013-01-01

Stress granules are a type of cytoplasmic messenger ribonucleoprotein (mRNP) granule formed in response to the inhibition of translation initiation, which typically occurs when cells are exposed to stress. Stress granules are conserved in eukaryotes; however, in filamentous fungi, including Aspergillus oryzae, stress granules have not yet been defined. For this reason, here we investigated the formation and localization of stress granules in A. oryzae cells exposed to various stresses using an EGFP fusion protein of AoPab1, a homolog of Saccharomyces cerevisiae Pab1p, as a stress granule marker. Localization analysis showed that AoPab1 was evenly distributed throughout the cytoplasm under normal growth conditions, and accumulated as cytoplasmic foci mainly at the hyphal tip in response to stress. AoSO, a homolog of Neurospora crassa SO, which is necessary for hyphal fusion, colocalized with stress granules in cells exposed to heat stress. The formation of cytoplasmic foci of AoSO was blocked by treatment with cycloheximide, a known inhibitor of stress granule formation. Deletion of the Aoso gene had effects on the formation and localization of stress granules in response to heat stress. Our results suggest that AoSO is a novel component of stress granules specific to filamentous fungi. The authors would specially like to thank Hiroyuki Nakano and Kei Saeki for generously providing experimental and insightful opinions.

Improving the temperature characteristics and catalytic efficiency of a mesophilic xylanase from Aspergillus oryzae, AoXyn11A, by iterative mutagenesis based on in silico design.

PubMed

Li, Xue-Qing; Wu, Qin; Hu, Die; Wang, Rui; Liu, Yan; Wu, Min-Chen; Li, Jian-Fang

2017-12-01

To improve the temperature characteristics and catalytic efficiency of a glycoside hydrolase family (GHF) 11 xylanase from Aspergillus oryzae (AoXyn11A), its variants were predicted based on in silico design. Firstly, Gly 21 with the maximum B-factor value, which was confirmed by molecular dynamics (MD) simulation on the three-dimensional structure of AoXyn11A, was subjected to site-saturation mutagenesis. Thus, one variant with the highest thermostability, AoXyn11A G21I , was selected from the mutagenesis library, E. coli/Aoxyn11A G21X (X: any one of 20 amino acids). Secondly, based on the primary structure multiple alignment of AoXyn11A with seven thermophilic GHF11 xylanases, AoXyn11A Y13F or AoXyn11A G21I-Y13F , was designed by replacing Tyr 13 in AoXyn11A or AoXyn11A G21I with Phe. Finally, three variant-encoding genes, Aoxyn11A G21I , Aoxyn11A Y13F and Aoxyn11A G21I-Y13F , were constructed by two-stage whole-plasmid PCR method, and expressed in Pichia pastoris GS115, respectively. The temperature optimum (T opt ) of recombinant (re) AoXyn11A G21I-Y13F was 60 °C, being 5 °C higher than that of reAoXyn11A G21I or reAoXyn11A Y13F , and 10 °C higher than that of reAoXyn11A. The thermal inactivation half-life (t 1/2 ) of reAoXyn11A G21I-Y13F at 50 °C was 240 min, being 40-, 3.4- and 2.5-fold longer than those of reAoXyn11A, reAoXyn11A G21I and reAoXyn11A Y13F . The melting temperature (T m ) values of reAoXyn11A, reAoXyn11A G21I , reAoXyn11A Y13F and reAoXyn11A G21I-Y13F were 52.3, 56.5, 58.6 and 61.3 °C, respectively. These findings indicated that the iterative mutagenesis of both Gly21Ile and Tyr13Phe improved the temperature characteristics of AoXyn11A in a synergistic mode. Besides those, the catalytic efficiency (k cat /K m ) of reAoXyn11A G21I-Y13F was 473.1 mL mg -1 s -1 , which was 1.65-fold higher than that of reAoXyn11A.

A-O Q-switching of 2.1-μm laser

NASA Astrophysics Data System (ADS)

Zheng, Jia; Liu, Jingjiao; Tang, Yi; Hu, Yongzhao

2005-01-01

2.1μm solid state laser operating at room temperature is a very useful laser source for optical communication, medical care, air pollution monitoring and Lidar, etc. It is eye-safe. It is also a very ideal pump source for optic parametric oscillator to get 3μm -5μm radiation. In order to further explore its potential applications, higher peak power and shorter pulse width are very desirable. Q-switching the laser is a most practical way to realize those goals. Among the most common used Q-switching techniques, mechanical Q-switching is not preferred due to that it involves use of a rotating motor, which has lower life time and causes undesirable vibration. E-O Q-switch material in this wavelength range is very expensive and quite susceptible to optical damage. On the other hand, low OH concentration quartz material exhibits very low absorption at the 2.1μm. The Cr:Tm:Ho:YAG 2.1μm laser has undesirable lower gain from the laser efficiency point of view, but offers a feasibility of using the A-O device for the Q-switching even the laser is pulse pumped. The Cr:Tm:Ho:YAG 2.1μm laser is a so called quasi-three level laser, which is characterized as having a higher threshold and lower gain. This study is focused on the optimization of the laser resonator design and the A-O Q-switch design for a higher laser peak power and shorter pulse width. Factors considered in the study include AO Q-switch"s RF frequency, modulation depth, active aperture, resonator length, resonator loss and pumping design, etc. Experiment results are compared with the Q-switched quasi-three level laser model. Final result of the Q-switched 2.1μm laser after preliminary optimization will be presented.

On Target Localization Using Combined RSS and AoA Measurements

PubMed Central

Beko, Marko; Dinis, Rui

2018-01-01

This work revises existing solutions for a problem of target localization in wireless sensor networks (WSNs), utilizing integrated measurements, namely received signal strength (RSS) and angle of arrival (AoA). The problem of RSS/AoA-based target localization became very popular in the research community recently, owing to its great applicability potential and relatively low implementation cost. Therefore, here, a comprehensive study of the state-of-the-art (SoA) solutions and their detailed analysis is presented. The beginning of this work starts by considering the SoA approaches based on convex relaxation techniques (more computationally complex in general), and it goes through other (less computationally complex) approaches, as well, such as the ones based on the generalized trust region sub-problems framework and linear least squares. Furthermore, a detailed analysis of the computational complexity of each solution is reviewed. Furthermore, an extensive set of simulation results is presented. Finally, the main conclusions are summarized, and a set of future aspects and trends that might be interesting for future research in this area is identified. PMID:29671832

An optical and X-ray survey of s-type Markarian galaxies

NASA Technical Reports Server (NTRS)

Hutter, D. J.; Mufson, S. L.

1981-01-01

The results of a study of 23 compact, lineless Markarian galaxies using broadband optical photometry and X-ray satellite observations are reported. The photometry shows that the sample can be broken into four groups. In one group (Mrk 180, 421, and 501) are composite objects in which a BL Lacertae object is embedded in an elliptical galaxy. For this group, the results of multiepoch X-ray observations using the HEAO-1 and -2 satellites are presented. In addition, photometry is used to decompose the optical emission into nonthermal and galactic components. In the second group are objects showing a small ultraviolet excess relative to normal galaxies. The X-ray survey indicates that the X-ray luminosity of objects in group 2 is much lower than those in group 1. This suggests that there is an intrinsic difference between objects in groups 1 and 2. The third and fourth groups are objects whose colors are indistinguishable from those of normal field galaxies and those of galactic stars, respectively. No X-ray emission was detected from objects in either of these groups.

The Performance of the Robo-AO Laser Guide Star Adaptive Optics System at the Kitt Peak 2.1 m Telescope

NASA Astrophysics Data System (ADS)

Jensen-Clem, Rebecca; Duev, Dmitry A.; Riddle, Reed; Salama, Maïssa; Baranec, Christoph; Law, Nicholas M.; Kulkarni, S. R.; Ramprakash, A. N.

2018-01-01

Robo-AO is an autonomous laser guide star adaptive optics (AO) system recently commissioned at the Kitt Peak 2.1 m telescope. With the ability to observe every clear night, Robo-AO at the 2.1 m telescope is the first dedicated AO observatory. This paper presents the imaging performance of the AO system in its first 18 months of operations. For a median seeing value of 1.″44, the average Strehl ratio is 4% in the i\\prime band. After post processing, the contrast ratio under sub-arcsecond seeing for a 2≤slant i\\prime ≤slant 16 primary star is five and seven magnitudes at radial offsets of 0.″5 and 1.″0, respectively. The data processing and archiving pipelines run automatically at the end of each night. The first stage of the processing pipeline shifts and adds the rapid frame rate data using techniques optimized for different signal-to-noise ratios. The second “high-contrast” stage of the pipeline is eponymously well suited to finding faint stellar companions. Currently, a range of scientific programs, including the synthetic tracking of near-Earth asteroids, the binarity of stars in young clusters, and weather on solar system planets are being undertaken with Robo-AO.

Directly Imaging Exoplanets and Resolving Asteroid Belts Around Young Stars with SCExAO+HiCIAO/VAMPIRES

NASA Astrophysics Data System (ADS)

Currie, Thayne

2015-06-01

We propose a unique, first-of-its-kind combined near-IR high-contrast imaging and optical interferometry study of 20 young, debris disk-bearing stars with SCExAO + HiCIAO/VAMPIRES. Our sample includes the benchmark imaged exoplanets HR 8799 bcde; luminous, resolvable debris disks; stars with asteroid belts that have yet to be resolved in scattered light; poorly-studied stars whose disks may be resolvable; and stars with compelling planet candidates requiring rapid follow-up. From proven VAMPIRES performance, SCExAO near-IR advances and HiCIAO software and hardware upgrades from our team, our data will 1) resolve known debris belts and possible hitherto unseen asteroid belts and 2) yield significantly deeper contrasts at small (r = 0.1"-0.5") separations than typical HiCIAO data (e.g. 10^{-5} at 0.4"). With the likely-operational Pyramid WFS, we will achieve extreme contrasts (< 10^{-6} at r > 0.25") and planet detection capabilities rivaling/exceeding those from GPI and SPHERE. Our program is guaranteed to result in many publications reporting new insights on known exoplanets and disks, may yield the first optical/IR images of exo-asteroid belts/other exoplanets, and could firmly establish Subaru/SCExAO as the premier extreme-AO exoplanet imaging facility.

Adaptive optics stochastic optical reconstruction microscopy (AO-STORM) by particle swarm optimization

PubMed Central

Tehrani, Kayvan F.; Zhang, Yiwen; Shen, Ping; Kner, Peter

2017-01-01

Stochastic optical reconstruction microscopy (STORM) can achieve resolutions of better than 20nm imaging single fluorescently labeled cells. However, when optical aberrations induced by larger biological samples degrade the point spread function (PSF), the localization accuracy and number of localizations are both reduced, destroying the resolution of STORM. Adaptive optics (AO) can be used to correct the wavefront, restoring the high resolution of STORM. A challenge for AO-STORM microscopy is the development of robust optimization algorithms which can efficiently correct the wavefront from stochastic raw STORM images. Here we present the implementation of a particle swarm optimization (PSO) approach with a Fourier metric for real-time correction of wavefront aberrations during STORM acquisition. We apply our approach to imaging boutons 100 μm deep inside the central nervous system (CNS) of Drosophila melanogaster larvae achieving a resolution of 146 nm. PMID:29188105

Adaptive optics stochastic optical reconstruction microscopy (AO-STORM) by particle swarm optimization.

PubMed

Tehrani, Kayvan F; Zhang, Yiwen; Shen, Ping; Kner, Peter

2017-11-01

Stochastic optical reconstruction microscopy (STORM) can achieve resolutions of better than 20nm imaging single fluorescently labeled cells. However, when optical aberrations induced by larger biological samples degrade the point spread function (PSF), the localization accuracy and number of localizations are both reduced, destroying the resolution of STORM. Adaptive optics (AO) can be used to correct the wavefront, restoring the high resolution of STORM. A challenge for AO-STORM microscopy is the development of robust optimization algorithms which can efficiently correct the wavefront from stochastic raw STORM images. Here we present the implementation of a particle swarm optimization (PSO) approach with a Fourier metric for real-time correction of wavefront aberrations during STORM acquisition. We apply our approach to imaging boutons 100 μm deep inside the central nervous system (CNS) of Drosophila melanogaster larvae achieving a resolution of 146 nm.

Correlation of AO and Lauge-Hansen classification systems for ankle fractures to the mechanism of injury.

PubMed

Rodriguez, Edward K; Kwon, John Y; Herder, Lindsay M; Appleton, Paul T

2013-11-01

Our aim was to assess whether the Lauge-Hansen (LH) and the Muller AO classification systems for ankle fractures radiographically correlate with in vivo injuries based on observed mechanism of injury. Videos of potential study candidates were reviewed on YouTube.com. Individuals were recruited for participation if the video could be classified by injury mechanism with a high likelihood of sustaining an ankle fracture. Corresponding injury radiographs were obtained. Injury mechanism was classified using the LH system as supination/external rotation (SER), supination/adduction (SAD), pronation/external rotation (PER), or pronation/abduction (PAB). Corresponding radiographs were classified by the LH system and the AO system. Thirty injury videos with their corresponding radiographs were collected. Of the video clips reviewed, 16 had SAD mechanisms and 14 had PER mechanisms. There were 26 ankle fractures, 3 nonfractures, and 1 subtalar dislocation. Twelve fractures with SAD mechanisms had corresponding SAD fracture patterns. Five PER mechanisms had PER fracture patterns. Eight PER mechanisms had SER fracture patterns and 1 had SAD fracture pattern. When the AO classification was used, all 12 SAD type injuries had a 44A type fracture, whereas the 14 PER injuries resulted in nine 44B fractures, two 44C fractures, and three 43A fractures. When injury video clips of ankle fractures were matched to their corresponding radiographs, the LH system was 65% (17/26) consistent in predicting fracture patterns from the deforming injury mechanism. When the AO classification system was used, consistency was 81% (21/26). The AO classification, despite its development as a purely radiographic system, correlated with in vivo injuries, as based on observed mechanism of injury, more closely than did the LH system. Level IV, case series.

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

Object Oriented Learning Objects

ERIC Educational Resources Information Center

Morris, Ed

2005-01-01

We apply the object oriented software engineering (OOSE) design methodology for software objects (SOs) to learning objects (LOs). OOSE extends and refines design principles for authoring dynamic reusable LOs. Our learning object class (LOC) is a template from which individualised LOs can be dynamically created for, or by, students. The properties…

X-ray Flaring Activity in HBL Source PKS 2155-304

NASA Astrophysics Data System (ADS)

Kapanadze, Bidzina

2013-08-01

We report an increasing X-ray flux through 0.3-10 keV band in the high-energy peaked BL Lacertae source PKS 2155-304 (z=0.117) which has been observed three times between 2013 July 25 and August 3 with the X-ray Telescope (XRT) onboard the Swift satellite. Using the data provided at the website http://www.swift.psu.edu/monitoring/ we have found that the object increased its 0.3-10 keV flux almost 3-times from 0.98+/-0.06 cts/s (July 25, ObsID=00030795114) to 2.85+/-0.08 cts/s corresponding to the observation performed July 31. The last pointing performed on August 3 (ObsID0008028002) shows even higher flux of 3.08+/-05 cts/s. No subhour flux variability at 99.9% confidence are detected from each observation, lasting 0.7 ks - 2.1 ks. On the basis of our recent study of long-term X-ray flux variability in this source (Kapanadze et al. 2013, submitted to the Monthly Notices of Royal Astronomical Society) we suggest that the similar situation was generally an indicator of the! onset of a longer-term flare with weeks-months duration. Therefore, further densely sampled observations with Swift-XRT and other X-ray instruments are highly recommended. Since X-ray flares in BL Lacertae sources are mostly followed by those in other spectral bands, we encourage intensive multiwavelength observations of PKS 2155-304.

The Effectiveness of a Mixed-Mode Survey on Domestic Violence in Curaçao: Response and Data Quality

ERIC Educational Resources Information Center

van Wijk, Nikil; de Leeuw, Edith; de Bruijn, Jeanne

2015-01-01

To collect reliable statistical data on domestic violence in Curaçao, we conducted a large-scale quantitative study (n = 816). To meet with the special needs of the population and topic, we designed a tailored mixed-mode survey to assess the prevalence of domestic violence in Curaçao and its health consequences. Great care was taken to reduce…

Aspect-Oriented Business Process Modeling with AO4BPMN

NASA Astrophysics Data System (ADS)

Charfi, Anis; Müller, Heiko; Mezini, Mira

Many crosscutting concerns in business processes need to be addressed already at the business process modeling level such as compliance, auditing, billing, and separation of duties. However, existing business process modeling languages including OMG's Business Process Modeling Notation (BPMN) lack appropriate means for expressing such concerns in a modular way. In this paper, we motivate the need for aspect-oriented concepts in business process modeling languages and propose an aspect-oriented extension to BPMN called AO4BPMN. We also present a graphical editor supporting that extension.

Are some BL Lacs artefacts of gravitational lensing?

PubMed

Ostriker, J P; Vietri, M

1990-03-01

WE suggested in 1985 that a significant fraction of BL Lacertae objects, a kind of lineless quasar, seen in nearby galaxies are in fact images, gravitationally lensed and substantially amplified by stars in the nearby galaxy, of background objects, optically violent variable (OVV) quasars at redshifts z > 1 (ref. 1). This hypothesis was made on the basis of certain general similarities between BL Lacs and O Ws, but for two recently observed BL Lacs(2,3) a strong case can be made that the accompanying elliptical galaxy is a foreground object. In addition, we argue that the distribution of BL Lac redshifts is hard to understand without gravitational lensing, unless we happen to be at a very local maximum of the spatial cosmic distribution of BL Lacs. Our analysis also indicates that the galaxies whose stars are likely to act as microlenses will be found in two peaks, one nearby, with redshift 0.05-0.10, and the other near the distant quasar.

Robo-AO Kepler Survey. IV. The Effect of Nearby Stars on 3857 Planetary Candidate Systems

NASA Astrophysics Data System (ADS)

Ziegler, Carl; Law, Nicholas M.; Baranec, Christoph; Riddle, Reed; Duev, Dmitry A.; Howard, Ward; Jensen-Clem, Rebecca; Kulkarni, S. R.; Morton, Tim; Salama, Maïssa

2018-04-01

We present the overall statistical results from the Robo-AO Kepler planetary candidate survey, comprising of 3857 high-angular resolution observations of planetary candidate systems with Robo-AO, an automated laser adaptive optics system. These observations reveal previously unknown nearby stars blended with the planetary candidate host stars that alter the derived planetary radii or may be the source of an astrophysical false positive transit signal. In the first three papers in the survey, we detected 440 nearby stars around 3313 planetary candidate host stars. In this paper, we present observations of 532 planetary candidate host stars, detecting 94 companions around 88 stars; 84 of these companions have not previously been observed in high resolution. We also report 50 more-widely separated companions near 715 targets previously observed by Robo-AO. We derive corrected planetary radius estimates for the 814 planetary candidates in systems with a detected nearby star. If planetary candidates are equally likely to orbit the primary or secondary star, the radius estimates for planetary candidates in systems with likely bound nearby stars increase by a factor of 1.54, on average. We find that 35 previously believed rocky planet candidates are likely not rocky due to the presence of nearby stars. From the combined data sets from the complete Robo-AO KOI survey, we find that 14.5 ± 0.5% of planetary candidate hosts have a nearby star with 4″, while 1.2% have two nearby stars, and 0.08% have three. We find that 16% of Earth-sized, 13% of Neptune-sized, 14% of Saturn-sized, and 19% of Jupiter-sized planet candidates have detected nearby stars.

Bacterial community analysis of anoxic/aeration (A/O) system in a combined process for gibberellin wastewater treatment

PubMed Central

Ouyang, Erming; Lu, Yao; Ouyang, Jiating; Wang, Lele; Wang, Xiaohui

2017-01-01

Gibberellin wastewater cannot be directly discharged without treatment due to its high concentrations of sulfate and organic compounds and strong acidity. Therefore, multi-stage anaerobic bioreactor + micro-aerobic+ anoxic/aeration (A/O) + biological contact oxidation combined processes are used to treat gibberellin wastewater. However, knowledge of the treatment effects of the A/O process and bacterial community structure in the aeration tank reactors of such systems is sparse. Therefore, this study was conducted to investigate the treatment effects and operation of the A/O process on gibberellin wastewater, as well as changes in the bacterial community structure of activated sludge in the aeration tank during treatment. Moreover, removal was examined based on evaluation of effluent after A/O treatment. Although influent chemical oxygen demand (COD), NH3-N and total phosphorus (TP) fluctuated, effluent COD, NH3-N and TP remained stable. Moreover, average COD, NH3-N and TP removal efficiency were 68.41%, 93.67% and 45.82%, respectively, during the A/O process. At the phylum level, Proteobacteria was the dominant phylum in all samples, followed by Chloroflexi, Bacteroidetes and Actinobacteria. Proteobacteria played an important role in the removal of organic matter. Chloroflexi was found to be responsible for the degradation of carbohydrates and Bacteroidetes also had been found to be responsible for the degradation of complex organic matters. Actinobacteria are able to degrade a variety of environmental chemicals. Additionally, Anaerolineaceae_uncultured was the major genus in samples collected on May 25, 2015, while Novosphingobium and Nitrospira were dominant in most samples. Nitrosomonas are regarded as the dominant ammonia-oxidizing bacteria, while Nitrospira are the main nitrite-oxidizing bacteria. Bacterial community structure varied considerably with time, and a partial Mantel test showed a highly significant positive correlation between bacterial community

Enhanced nitrogen removal from electroplating tail wastewater through two-staged anoxic-oxic (A/O) process.

PubMed

Yan, Xinmei; Zhu, Chunyan; Huang, Bin; Yan, Qun; Zhang, Guangsheng

2018-01-01

Consisted of anaerobic (ANA), anoxic-1 (AN1), aerobic-1 (AE1), anoxic-2 (AN2), aerobic-2 (AE2) reactors and sediment tank, the two-staged A/O process was applied for depth treatment of electroplating tail wastewater with high electrical conductivity and large amounts of ammonia nitrogen. It was found that the NH 4 + -N and COD removal efficiencies reached 97.11% and 83.00%, respectively. Besides, the short-term salinity shock of the control, AE1 and AE2 indicated that AE1 and AE2 have better resistance to high salinity when the concentration of NaCl ranged from 1 to 10g/L. Meanwhile, it was found through high-throughput sequencing that bacteria genus Nitrosomonas, Nitrospira and Thauera, which are capable of nitrogen removal, were enriched in the two-staged A/O process. Moreover, both salt-tolerant bacteria and halophili bacteria were also found in the combined process. Therefore, microbial community within the two-staged A/O process could be acclimated to high electrical conductivity, and adapted for electroplating tail wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multi-wavelength Observations of the Flaring Gamma-ray Blazar 3C 66A in 2008 October

NASA Astrophysics Data System (ADS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Costamante, L.; Cutini, S.; Davis, D. S.; Dermer, C. D.; de Palma, F.; Digel, S. W.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Favuzzi, C.; Fegan, S. J.; Fortin, P.; Frailis, M.; Fuhrmann, L.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Itoh, R.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Naumann-Godo, M.; Nestoras, I.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reyes, L. C.; Ripken, J.; Ritz, S.; Romani, R. W.; Roth, M.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Scargle, J. D.; Sgrò, C.; Shaw, M. S.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.; Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Beilicke, M.; Benbow, W.; Böttcher, M.; Boltuch, D.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Christiansen, J. L.; Ciupik, L.; Cui, W.; de la Calle Perez, I.; Dickherber, R.; Errando, M.; Falcone, A.; Finley, J. P.; Finnegan, G.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Gillanders, G. H.; Godambe, S.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Holder, J.; Hui, C. M.; Humensky, T. B.; Imran, A.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; LeBohec, S.; Maier, G.; McArthur, S.; McCann, A.; McCutcheon, M.; Moriarty, P.; Mukherjee, R.; Ong, R. A.; Otte, A. N.; Pandel, D.; Perkins, J. S.; Pichel, A.; Pohl, M.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Schroedter, M.; Sembroski, G. H.; Senturk, G. Demet; Smith, A. W.; Steele, D.; Swordy, S. P.; Tešić, G.; Theiling, M.; Thibadeau, S.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wissel, S.; Wood, M.; Villata, M.; Raiteri, C. M.; Gurwell, M. A.; Larionov, V. M.; Kurtanidze, O. M.; Aller, M. F.; Lähteenmäki, A.; Chen, W. P.; Berduygin, A.; Agudo, I.; Aller, H. D.; Arkharov, A. A.; Bach, U.; Bachev, R.; Beltrame, P.; Benítez, E.; Buemi, C. S.; Dashti, J.; Calcidese, P.; Capezzali, D.; Carosati, D.; Da Rio, D.; Di Paola, A.; Diltz, C.; Dolci, M.; Dultzin, D.; Forné, E.; Gómez, J. L.; Hagen-Thorn, V. A.; Halkola, A.; Heidt, J.; Hiriart, D.; Hovatta, T.; Hsiao, H.-Y.; Jorstad, S. G.; Kimeridze, G. N.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Leto, P.; Ligustri, R.; Lindfors, E.; Lopez, J. M.; Marscher, A. P.; Mommert, M.; Mujica, R.; Nikolashvili, M. G.; Nilsson, K.; Palma, N.; Pasanen, M.; Roca-Sogorb, M.; Ros, J. A.; Roustazadeh, P.; Sadun, A. C.; Saino, J.; Sigua, L. A.; Sillanää, A.; Sorcia, M.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Turchetti, R.; Umana, G.; Belloni, T.; Blake, C. H.; Bloom, J. S.; Angelakis, E.; Fumagalli, M.; Hauser, M.; Prochaska, J. X.; Riquelme, D.; Sievers, A.; Starr, D. L.; Tagliaferri, G.; Ungerechts, H.; Wagner, S.; Zensus, J. A.; Fermi LAT Collaboration; VERITAS Collaboration; GASP-WEBT Consortium

2011-01-01

The BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra provided radio to X-ray coverage. The available light curves show variability and, in particular, correlated flares are observed in the optical and Fermi-LAT gamma-ray band. The resulting spectral energy distribution can be well fitted using standard leptonic models with and without an external radiation field for inverse Compton scattering. It is found, however, that only the model with an external radiation field can accommodate the intra-night variability observed at optical wavelengths.

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

The angular resolution of ground-based optical telescopes is limited by the degrading effects of the turbulent atmosphere. In the absence of an atmosphere, the angular resolution of a typical telescope is limited only by diffraction, i.e., the wavelength of interest, λ, divided by the size of its primary mirror's aperture, D. For example, the Hubble Space Telescope (HST), with a 2.4-m primary mirror, has an angular resolution at visible wavelengths of ~0.04 arc seconds. The atmosphere is composed of air at slightly different temperatures, and therefore different indices of refraction, constantly mixing. Light waves are bent as they pass through the inhomogeneous atmosphere. When a telescope on the ground focuses these light waves, instantaneous images appear fragmented, changing as a function of time. As a result, long-exposure images acquired using ground-based telescopes - even telescopes with four times the diameter of HST - appear blurry and have an angular resolution of roughly 0.5 to 1.5 arc seconds at best. Astronomical adaptive-optics systems compensate for the effects of atmospheric turbulence. First, the shape of the incoming non-planar wave is determined using measurements of a nearby bright star by a wavefront sensor. Next, an element in the optical system, such as a deformable mirror, is commanded to correct the shape of the incoming light wave. Additional corrections are made at a rate sufficient to keep up with the dynamically changing atmosphere through which the telescope looks, ultimately producing diffraction-limited images. The fidelity of the wavefront sensor measurement is based upon how well the incoming light is spatially and temporally sampled1. Finer sampling requires brighter reference objects. While the brightest stars can serve as reference objects for imaging targets from several to tens of arc seconds away in the best conditions, most interesting astronomical targets do not have sufficiently bright stars nearby. One solution is to

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

2013-02-12

The angular resolution of ground-based optical telescopes is limited by the degrading effects of the turbulent atmosphere. In the absence of an atmosphere, the angular resolution of a typical telescope is limited only by diffraction, i.e., the wavelength of interest, λ, divided by the size of its primary mirror's aperture, D. For example, the Hubble Space Telescope (HST), with a 2.4-m primary mirror, has an angular resolution at visible wavelengths of ~0.04 arc seconds. The atmosphere is composed of air at slightly different temperatures, and therefore different indices of refraction, constantly mixing. Light waves are bent as they pass through the inhomogeneous atmosphere. When a telescope on the ground focuses these light waves, instantaneous images appear fragmented, changing as a function of time. As a result, long-exposure images acquired using ground-based telescopes--even telescopes with four times the diameter of HST--appear blurry and have an angular resolution of roughly 0.5 to 1.5 arc seconds at best. Astronomical adaptive-optics systems compensate for the effects of atmospheric turbulence. First, the shape of the incoming non-planar wave is determined using measurements of a nearby bright star by a wavefront sensor. Next, an element in the optical system, such as a deformable mirror, is commanded to correct the shape of the incoming light wave. Additional corrections are made at a rate sufficient to keep up with the dynamically changing atmosphere through which the telescope looks, ultimately producing diffraction-limited images. The fidelity of the wavefront sensor measurement is based upon how well the incoming light is spatially and temporally sampled. Finer sampling requires brighter reference objects. While the brightest stars can serve as reference objects for imaging targets from several to tens of arc seconds away in the best conditions, most interesting astronomical targets do not have sufficiently bright stars nearby. One solution is to focus

Atomic Oxygen (AO) and Nitrogen (AN) In-situ Flux Sensor

DTIC Science & Technology

2016-03-10

AFRL-AFOSR-VA-TR-2016-0126 DURIP 09) AN ATOMIC OXYGEN FLUX MONITOR FOR USE IN THE SEARCH FOR NEW AND BETT Malcolm Beasley LELAND STANFORD JUNIOR UNIV...Grant # FA9550-01-1-0433 M. R. Beasley, PI Stanford University Project Title: Atomic Oxygen (AO) and Nitrogen (AN) In-situ Flux Sensor...of actively controlled in-situ sources of atomic oxygen and nitrogen suitable for MBE application. The goal of this DURIP was to work with a

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

MagAO Imaging of Long-period Objects (MILO). II. A Puzzling White Dwarf around the Sun-like Star HD 11112

NASA Astrophysics Data System (ADS)

Rodigas, Timothy J.; Bergeron, P.; Simon, Amélie; Arriagada, Pamela; Faherty, Jacqueline K.; Anglada-Escudé, Guillem; Mamajek, Eric E.; Weinberger, Alycia; Butler, R. Paul; Males, Jared R.; Morzinski, Katie; Close, Laird M.; Hinz, Philip M.; Bailey, Jeremy; Carter, Brad; Jenkins, James S.; Jones, Hugh; O'Toole, Simon; Tinney, C. G.; Wittenmyer, Rob; Debes, John

2016-11-01

HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2.″2 (100 au) at multiple wavelengths spanning 0.6-4 μm and show that it is most likely a gravitationally bound cool white dwarf. Modeling its spectral energy distribution suggests that its mass is 0.9-1.1 M ⊙, which corresponds to very high eccentricity, near edge-on orbits from a Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is >2σ, which is discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years.

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.

ViLLaGEs: opto-mechanical design of an on-sky visible-light MEMS-based AO system

NASA Astrophysics Data System (ADS)

Grigsby, Bryant; Lockwood, Chris; Baumann, Brian; Gavel, Don; Johnson, Jess; Ammons, S. Mark; Dillon, Daren; Morzinski, Katie; Reinig, Marc; Palmer, Dave; Severson, Scott; Gates, Elinor

2008-07-01

Visible Light Laser Guidestar Experiments (ViLLaGEs) is a new Micro-Electro Mechanical Systems (MEMS) based visible-wavelength adaptive optics (AO) testbed on the Nickel 1-meter telescope at Lick Observatory. Closed loop Natural Guide Star (NGS) experiments were successfully carried out during engineering during the fall of 2007. This is a major evolutionary step, signaling the movement of AO technologies into visible light with a MEMS mirror. With on-sky Strehls in I-band of greater than 20% during second light tests, the science possibilities have become evident. Described here is the advanced engineering used in the design and construction of the ViLLaGEs system, comparing it to the LickAO infrared system, and a discussion of Nickel dome infrastructural improvements necessary for this system. A significant portion of the engineering discussion revolves around the sizable effort that went towards eliminating flexure. Then, we detail upgrades to ViLLaGEs to make it a facility class instrument. These upgrades will focus on Nyquist sampling the diffraction limited point spread function during open loop operations, motorization and automation for technician level alignments, adding dithering capabilities and changes for near infrared science.

Seasonal and Interannual Variability of the Arctic Sea Ice: A Comparison between AO-FVCOM and Observations

NASA Astrophysics Data System (ADS)

Zhang, Y.; Chen, C.; Beardsley, R. C.; Gao, G.; Qi, J.; Lin, H.

2016-02-01

A high-resolution (up to 2 km), unstructured-grid, fully ice-sea coupled Arctic Ocean Finite-Volume Community Ocean Model (AO-FVCOM) was used to simulate the Arctic sea ice over the period 1978-2014. Good agreements were found between simulated and observed sea ice extent, concentration, drift velocity and thickness, indicating that the AO-FVCOM captured not only the seasonal and interannual variability but also the spatial distribution of the sea ice in the Arctic in the past 37 years. Compared with other six Arctic Ocean models (ECCO2, GSFC, INMOM, ORCA, NAME and UW), the AO-FVCOM-simulated ice thickness showed a higher correlation coefficient and a smaller difference with observations. An effort was also made to examine the physical processes attributing to the model-produced bias in the sea ice simulation. The error in the direction of the ice drift velocity was sensitive to the wind turning angle; smaller when the wind was stronger, but larger when the wind was weaker. This error could lead to the bias in the near-surface current in the fully or partially ice-covered zone where the ice-sea interfacial stress was a major driving force.

Target-object integration, attention distribution, and object orientation interactively modulate object-based selection.

PubMed

Al-Janabi, Shahd; Greenberg, Adam S

2016-10-01

The representational basis of attentional selection can be object-based. Various studies have suggested, however, that object-based selection is less robust than spatial selection across experimental paradigms. We sought to examine the manner by which the following factors might explain this variation: Target-Object Integration (targets 'on' vs. part 'of' an object), Attention Distribution (narrow vs. wide), and Object Orientation (horizontal vs. vertical). In Experiment 1, participants discriminated between two targets presented 'on' an object in one session, or presented as a change 'of' an object in another session. There was no spatial cue-thus, attention was initially focused widely-and the objects were horizontal or vertical. We found evidence of object-based selection only when targets constituted a change 'of' an object. Additionally, object orientation modulated the sign of object-based selection: We observed a same-object advantage for horizontal objects, but a same-object cost for vertical objects. In Experiment 2, an informative cue preceded a single target presented 'on' an object or as a change 'of' an object (thus, attention was initially focused narrowly). Unlike in Experiment 1, we found evidence of object-based selection independent of target-object integration. We again found that the sign of selection was modulated by the objects' orientation. This result may reflect a meridian effect, which emerged due to anisotropies in the cortical representations when attention is oriented endogenously. Experiment 3 revealed that object orientation did not modulate object-based selection when attention was oriented exogenously. Our findings suggest that target-object integration, attention distribution, and object orientation modulate object-based selection, but only in combination.

MagAO IMAGING OF LONG-PERIOD OBJECTS (MILO). II. A PUZZLING WHITE DWARF AROUND THE SUN-LIKE STAR HD 11112

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodigas, Timothy J.; Arriagada, Pamela; Faherty, Jacqueline K.

HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2.″2 (100 au) at multiple wavelengths spanning 0.6–4 μ m and show that it is most likely a gravitationally bound cool white dwarf. Modeling its spectral energy distribution suggests that its mass is 0.9–1.1 M {sub ⊙}, which corresponds to very high eccentricity, near edge-on orbits from amore » Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is >2 σ , which is discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Y.-L.; Close, L. M.; Males, J. 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 thatmore » 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}.« less

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.

Mitochondria-localized phospholipase A2, AoPlaA, in Aspergillus oryzae displays phosphatidylethanolamine-specific activity and is involved in the maintenance of mitochondrial phospholipid composition.

PubMed

Kotani, Shohei; Izawa, Sho; Komai, Noriyuki; Takayanagi, Ayumi; Arioka, Manabu

2016-11-01

In mammals, cytosolic phospholipases A 2 (cPLA 2 s) play important physiological roles by releasing arachidonic acid, a precursor for bioactive lipid mediators, from the biological membranes. In contrast, fungal cPLA 2 -like proteins are much less characterized and their roles have remained elusive. AoPlaA is a cPLA 2 -like protein in the filamentous fungus Aspergillus oryzae which, unlike mammalian cPLA 2 , localizes to mitochondria. In this study, we investigated the biochemical and physiological functions of AoPlaA. Recombinant AoPlaA produced in E. coli displayed Ca 2+ -independent lipolytic activity. Mass spectrometry analysis demonstrated that AoPlaA displayed PLA 2 activity to phosphatidylethanolamine (PE), but not to other phospholipids, and generated 1-acylated lysoPE. Catalytic site mutants of AoPlaA displayed almost no or largely reduced activity to PE. Consistent with PE-specific activity of AoPlaA, AoplaA-overexpressing strain showed decreased PE content in the mitochondrial fraction. In contrast, AoplaA-disruption strain displayed increased content of cardiolipin. AoplaA-overexpressing strain, but not its counterparts overexpressing the catalytic site mutants, exhibited retarded growth at low temperature, possibly because of the impairment of the mitochondrial function caused by excess degradation of PE. These results suggest that AoPlaA is a novel PE-specific PLA 2 that plays a regulatory role in the maintenance of mitochondrial phospholipid composition. Copyright © 2016 Elsevier Inc. All rights reserved.

Multi-wavelength observations of the flaring gamma-ray blazar 3C 66A in 2008 October

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2010-12-14

We report that Tthe BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra provided radio to X-ray coverage. The available light curves show variability and, in particular, correlated flares are observed in the optical and Fermi-LAT gamma-ray band. The resulting spectral energy distribution can be well fitted using standard leptonic models with and without an external radiation field for inverse Compton scattering. It is found, however, that only the model with anmore » external radiation field can accommodate the intra-night variability observed at optical wavelengths.« less

AO WFS detector developments at ESO to prepare for the E-ELT

NASA Astrophysics Data System (ADS)

Downing, Mark; Casali, Mark; Finger, Gert; Lewis, Steffan; Marchetti, Enrico; Mehrgan, Leander; Ramsay, Suzanne; Reyes, Javier

2016-07-01

ESO has a very active on-going AO WFS detector development program to not only meet the needs of the current crop of instruments for the VLT, but also has been actively involved in gathering requirements, planning, and developing detectors and controllers/cameras for the instruments in design and being proposed for the E-ELT. This paper provides an overall summary of the AO WFS Detector requirements of the E-ELT instruments currently in design and telescope focal units. This is followed by a description of the many interesting detector, controller, and camera developments underway at ESO to meet these needs; a) the rationale behind and plan to upgrade the 240x240 pixels, 2000fps, "zero noise", L3Vision CCD220 sensor based AONGC camera; b) status of the LGSD/NGSD High QE, 3e- RoN, fast 700fps, 1760x1680 pixels, Visible CMOS Imager and camera development; c) status of and development plans for the Selex SAPHIRA NIR eAPD and controller. Most of the instruments and detector/camera developments are described in more detail in other papers at this conference.

Object-based benefits without object-based representations.

PubMed

Fougnie, Daryl; Cormiea, Sarah M; Alvarez, George A

2013-08-01

Influential theories of visual working memory have proposed that the basic units of memory are integrated object representations. Key support for this proposal is provided by the same object benefit: It is easier to remember multiple features of a single object than the same set of features distributed across multiple objects. Here, we replicate the object benefit but demonstrate that features are not stored as single, integrated representations. Specifically, participants could remember 10 features better when arranged in 5 objects compared to 10 objects, yet memory for one object feature was largely independent of memory for the other object feature. These results rule out the possibility that integrated representations drive the object benefit and require a revision of the concept of object-based memory representations. We propose that working memory is object-based in regard to the factors that enhance performance but feature based in regard to the level of representational failure. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Induced abortion is not associated with a higher likelihood of depression in Curaçao women.

PubMed

Boersma, Adriana A; van den Berg, Desirée; van Lunsen, Rik H W; Laan, Ellen T M

2014-10-01

To investigate the risk of developing a depression after induced abortion. A prospective cohort study conducted in Curaçao which involved 92 women having an induced abortion and 37 women delivering after an unplanned or unwanted pregnancy, who served as controls. All participants completed the Center of Epidemiological Studies Depression (CES-D) scale before and two to three weeks after the abortion or delivery. Following the abortion, significantly fewer women were at risk of depression (30%) as compared to when still pregnant (60%). Mean depression scores were significantly lower after- than before the procedure. The likelihood of depression post-abortum (30%) was similar to that after delivery of an unplanned/unwanted child (22%). Even though women in the abortion group more often reported having suffered from depression in the past than controls, they were not at greater risk of depression after their pregnancy had ended. Curaçao women's risk of developing a depression following an (early) induced abortion is not greater than that after carrying to term an unplanned/unwanted pregnancy. We recommend that the results of this study be taken into account in case the Curaçao government should consider legalisation of induced abortion in the near future.

Dust and Diffuse Interstellar Bands in the za = 0.524 Absorption System toward AO 0235+164

NASA Astrophysics Data System (ADS)

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

2004-10-01

We present new Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) NUV-MAMA and STIS CCD observations of the BL Lac object AO 0235+164 and the intervening damped Lyα (DLA) line at za=0.524. The line profile gives N(HI)=(5+/-1)×1021 cm-2 and, combined with the H I 21 cm absorption data, leads to a spin temperature of Ts=220+/-60 K. Those spectra also show a strong, broad feature at the expected position of the 2175 Å graphitic dust feature at za=0.524. Assuming a Galactic-type dust extinction curve at za=0.524 gives a dust-to-gas ratio of 0.19 times the Galactic value, but the fit, assuming that the underlying, unreddened spectrum is a single power law, is poor in the far-UV. A dust-to-gas ratio of 0.19 times the Galactic value is similar to the LMC, but the AO 0235+164 spectrum does not fit either the LMC extinction curve or the SMC extinction curve (which has practically no 2175 Å feature). A possible interpretation includes dust similar to that in the Galaxy, but with fewer of the small particles that produce the far-UV extinction. The metallicity of the za=0.524 absorber, estimated from the observed N(HI) and excess X-ray absorption (beyond Galactic) derived from contemporaneous and archival ASCA and ROSAT X-ray data, is Z=0.72+/-0.28 Zsolar, implying in turn a dust-to-metals ratio of 0.27 times the Galactic value. If the dust mass density is the same in the za=0.524 DLA system as in our Galaxy, only 14% (+/-6%) of the metals (by mass) are in dust, compared to 51%, 36%, and 46% for the Galaxy, LMC, and SMC, respectively. Such a dusty za=0.524 AO 0235+164 absorption system is a good example of the kind of DLA system that will be missed because of selection effects, which in turn can bias the measurement of the comoving density of interstellar gas (in units of the closure density), Ωg, as a function of z. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by

Objects of attention, objects of perception.

PubMed

Avrahami, J

1999-11-01

Four experiments were conducted, to explore the notion of objects in perception. Taking as a starting point the effects of display content on rapid attention transfer and manipulating curvature, closure, and processing time, a link between objects of attention and objects of perception is proposed. In Experiment 1, a number of parallel, equally spaced, straight lines facilitated attention transfer along the lines, relative to transfer across the lines. In Experiment 2, with curved, closed-contour shapes, no "same-object" facilitation was observed. However, when a longer time interval was provided, in Experiment 3, a same-object advantage started to emerge. In Experiment 4, using the same curved shapes but in a non-speeded distance estimation task, a strong effect of objects was observed. It is argued that attention transfer is facilitated by line tracing but that line tracing is encouraged by objects.

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.

VizieR Online Data Catalog: Robo-AO observed cool subdwarf companions (Ziegler+, 2015)

NASA Astrophysics Data System (ADS)

Ziegler, C.; Law, N. M.; Baranec, C.; Riddle, R. L.; Fuchs, J. T.

2017-09-01

We selected targets from the 564 spectral type F- through M-subdwarf candidates studied by Marshall (2007, J/AJ/134/778). These targets were selected from the New Luyten Two-Tenths catalog (NLTT; Luyten, 1979nlcs.book.....L; Luyten & Hughes 1980, Proper-Motion Survey with the Forty-Eight Inch Schmidt Telescope LV First Supplement to the NLTT Catalogue (Minneapolis, MN: Univ. Minnesota Press)) of high proper motion stars (>0.18 arcsec/yr) using a reduced proper motion diagram (RPM). Of the 552 subdwarfs confirmed by Marshall, a randomly selected sample of 348 G-, K-, and M-subdwarfs were observed by Robo-AO when available between other high priority surveys. We obtained high-angular-resolution images of the 348 subdwarfs during 32 separate nights of observations between 2012 September 3 and 2013 August 21 (UT). The observations were performed using the Robo-AO laser adaptive optics system (Riddle et al. 2012SPIE.8447E..2OR; Baranec et al. 2013, J. Visualized Exp. 72 e50021; 2014ApJ...790L...8B) mounted on the Palomar 60 inch telescope. (1 data file).

Object width modulates object-based attentional selection.

PubMed

Nah, Joseph C; Neppi-Modona, Marco; Strother, Lars; Behrmann, Marlene; Shomstein, Sarah

2018-04-24

Visual input typically includes a myriad of objects, some of which are selected for further processing. While these objects vary in shape and size, most evidence supporting object-based guidance of attention is drawn from paradigms employing two identical objects. Importantly, object size is a readily perceived stimulus dimension, and whether it modulates the distribution of attention remains an open question. Across four experiments, the size of the objects in the display was manipulated in a modified version of the two-rectangle paradigm. In Experiment 1, two identical parallel rectangles of two sizes (thin or thick) were presented. Experiments 2-4 employed identical trapezoids (each having a thin and thick end), inverted in orientation. In the experiments, one end of an object was cued and participants performed either a T/L discrimination or a simple target-detection task. Combined results show that, in addition to the standard object-based attentional advantage, there was a further attentional benefit for processing information contained in the thick versus thin end of objects. Additionally, eye-tracking measures demonstrated increased saccade precision towards thick object ends, suggesting that Fitts's Law may play a role in object-based attentional shifts. Taken together, these results suggest that object-based attentional selection is modulated by object width.

Computer simulations and real-time control of ELT AO systems using graphical processing units

NASA Astrophysics Data System (ADS)

Wang, Lianqi; Ellerbroek, Brent

2012-07-01

The adaptive optics (AO) simulations at the Thirty Meter Telescope (TMT) have been carried out using the efficient, C based multi-threaded adaptive optics simulator (MAOS, http://github.com/lianqiw/maos). By porting time-critical parts of MAOS to graphical processing units (GPU) using NVIDIA CUDA technology, we achieved a 10 fold speed up for each GTX 580 GPU used compared to a modern quad core CPU. Each time step of full scale end to end simulation for the TMT narrow field infrared AO system (NFIRAOS) takes only 0.11 second in a desktop with two GTX 580s. We also demonstrate that the TMT minimum variance reconstructor can be assembled in matrix vector multiply (MVM) format in 8 seconds with 8 GTX 580 GPUs, meeting the TMT requirement for updating the reconstructor. Analysis show that it is also possible to apply the MVM using 8 GTX 580s within the required latency.

Outcomes and complications of fractures of distal radius (AO type B and C): volar plating versus nonoperative treatment.

PubMed

Sharma, Himanshu; Khare, Ghanshyam Narayan; Singh, Saurabh; Ramaswamy, Arun Govindraj; Kumaraswamy, Vinay; Singh, Ashutosh Kumar

2014-07-01

Management of AO type B and C fractures of the distal radius is controversial. This study compares outcomes and complications of AO type B and C fractures of the distal radius treated with volar locked plating and nonoperative methods. Sixty-four patients with fractures of the distal radius (AO type B and C) were included in this study, according to inclusion criteria, and were allocated to the volar plating group or nonoperative group by alternate randomization: 32 patients with odd numbers went into the nonoperative group and the other 32 with even numbers went into the volar plating group. Patients in the nonoperative group were managed with closed reduction of the fracture and plaster cast application under an image intensifier. Those in the volar plating group were managed by open reduction and fixation with a volar locked plate. Preoperative and postoperative serial clinico-radiological follow-up was done. The range of movement, grip strength, functional outcome scores and radiological parameters were compared. Student's t-test was used for statistical analysis with significance at p < 0.05. Range of movement and functional scores were significantly (p < 0.001) better in the volar plating group, but the difference in ulnar variance and radial and ulnar deviation was insignificant as compared to the nonoperative group. At 24 months follow-up, the nonoperative group had significantly more cases with malunion, articular incongruity and osteoarthritis. In cases of AO type B or C fractures of the distal radius, volar locked plating provides anatomical stable fixation and early mobilization with better clinico-radiological outcome as compared to conservative treatment.

CCD photometry of 1218+304 1219+28 and 1727+50: Point sources, associated nebulosity and broadband spectra

NASA Technical Reports Server (NTRS)

Weistrop, D.; Shaffer, D. B.; Mushotzky, R. F.; Reitsma, H. J.; Smith, B. A.

1981-01-01

Visual and far red surface photometry were obtained of two X-ray emitting BL Lacertae objects, 1218+304 (2A1219+305) and 1727+50 (Izw 187), as well as the highly variable object 1219+28 (ON 231, W Com). The intensity distribution for 1727+50 can be modeled using a central point source plus a de Vaucouleurs intensity law for an underlying galaxy. The broad band spectral energy distribution so derived is consistent with what is expected for an elliptical galaxy. The spectral index of the point source is alpha = 0.97. Additional VLBI and X-ray data are also reported for 1727+50. There is nebulosity associated with the recently discovered object 1218+304. No nebulosity is found associated with 1219+28. A comparison of the results with observations at X-ray and radio frequencies suggests that all the emission from 1727+50 and 1218+304 can be interpreted as due solely to direct synchrotron emission. If this is the case, the data further imply the existence of relativistic motion effects and continuous particle injection.

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

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

NASA Astrophysics Data System (ADS)

Bourrieau, J.

1993-04-01

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

Use of Self-to-Object and Object-to-Object Spatial Relations in Locomotion

ERIC Educational Resources Information Center

Xiao, Chengli; Mou, Weimin; McNamara, Timothy P.

2009-01-01

In 8 experiments, the authors examined the use of representations of self-to-object or object-to-object spatial relations during locomotion. Participants learned geometrically regular or irregular layouts of objects while standing at the edge or in the middle and then pointed to objects while blindfolded in 3 conditions: before turning (baseline),…

Observations and analysis activities of the International Ultraviolet Explorer satellite telescope

NASA Technical Reports Server (NTRS)

Shull, J. Michael

1996-01-01

The funds from this grant were used to support observations and analysis with the International Ultraviolet Explorer (IUE) satellite telescope. The main area of scientific research concerned the variability analyses of ultraviolet spectra of Active Galactic Nuclei, primarily quasars, Seyfert galaxies, and BL Lacertae objects. The Colorado group included, at various times, the P.I. (J.M. Shull), Research Associate Dr. Rick Edelson, and graduate students Jon Saken, Elise Sachs, and Steve Penton. A portion of the work was also performed by CU undergraduate student Cheong-ming Fu. A major product of the effort was a database of all IUE spectra of active galactic nuclei. This database is being analyzed to obtain spectral indices, line fluxes, and continuum fluxes for over 500 AGN. As a by-product of this project, we implemented a new, improved technique of spectral extraction of IUE spectra, which has been used in several AGN-WATCH campaigns (on the Seyfert galaxy NGC 4151 and on the BL Lac object PKS 2155-304).

Instrument control software development process for the multi-star AO system ARGOS

NASA Astrophysics Data System (ADS)

Kulas, M.; Barl, L.; Borelli, J. L.; Gässler, W.; Rabien, S.

2012-09-01

The ARGOS project (Advanced Rayleigh guided Ground layer adaptive Optics System) will upgrade the Large Binocular Telescope (LBT) with an AO System consisting of six Rayleigh laser guide stars. This adaptive optics system integrates several control loops and many different components like lasers, calibration swing arms and slope computers that are dispersed throughout the telescope. The purpose of the instrument control software (ICS) is running this AO system and providing convenient client interfaces to the instruments and the control loops. The challenges for the ARGOS ICS are the development of a distributed and safety-critical software system with no defects in a short time, the creation of huge and complex software programs with a maintainable code base, the delivery of software components with the desired functionality and the support of geographically distributed project partners. To tackle these difficult tasks, the ARGOS software engineers reuse existing software like the novel middleware from LINC-NIRVANA, an instrument for the LBT, provide many tests at different functional levels like unit tests and regression tests, agree about code and architecture style and deliver software incrementally while closely collaborating with the project partners. Many ARGOS ICS components are already successfully in use in the laboratories for testing ARGOS control loops.

FlyEyes: A CCD-Based Wavefront Sensor for PUEO, the CFHT Curvature AO System

DTIC Science & Technology

2010-09-28

Charles Cuillandre, Kevin K.Y. Ho, Marc Baril , Tom Benedict, Jeff Ward, Jim Thomas, Derrick Salmon, Chueh-Jen Lin, Shiang-Yu Wang, Gerry Luppino...sensor for PUEO, the CFHT curvature AO system Olivier Lai, Jean-Charles Cuillandre , Kevin K.Y. Ho, lVIarc Baril , Tom Benedict, Jeff ’Varel, Jim Thomas

Very Accurate Imaging of the Close Environment of Bright Objects in Visible and Near-Infrared

NASA Astrophysics Data System (ADS)

Mouillet, David; Beuzit, Jean-Luc; Chauvin, Gael; Lagrange, Anne-Marie

The development of adaptive optics (AO) in near IR has demonstrated in the latest decade both its astronomical impact and its increasing importance with the development of larger telescopes. We emphasize that still better imaging capabilities would extend the wavelength range from near-IR to visible and would also enable to perform very high dynamic observations from the ground. Such a gain in performance is interesting for a large number of astrophysical topics: environment of young stellar objects, evolved stars, binary or multiple systems, planetary disks and low mass companions down to brown dwarves or hot planets. The specification of an instrument fulfilling such requirements could be focussed on high image quality on a narrow field around bright objects, so as to limit the cost and development timescale. Additionally, this facility could also be used (with the same specifications) to feed other future instruments (such as interferometers or high resolution spectrometers working in visible) and would be an important step in the general scheme of larger adaptive optics systems development.

Multi-wavelength Observations of Blazar AO 0235+164 in the 2008-2009 Flaring State

NASA Astrophysics Data System (ADS)

Ackermann, M.; Ajello, M.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cutini, S.; D'Ammando, F.; de Palma, F.; Dermer, C. D.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Fuhrmann, L.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hughes, R. E.; Itoh, R.; Jóhannesson, G.; Johnson, A. S.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Lee, S.-H.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nishino, S.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Pelassa, V.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Rastawicki, D.; Razzano, M.; Readhead, A.; Reimer, A.; Reimer, O.; Reyes, L. C.; Richards, J. L.; Sbarra, C.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Szostek, A.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Zimmer, S.; Fermi-LAT Collaboration; Moderski, R.; Nalewajko, K.; Sikora, M.; Villata, M.; Raiteri, C. M.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Benítez, E.; Berdyugin, A.; Blinov, D. A.; Boettcher, M.; Bravo Calle, O. J. A.; Buemi, C. S.; Carosati, D.; Chen, W. P.; Diltz, C.; Di Paola, A.; Dolci, M.; Efimova, N. V.; Forné, E.; Gurwell, M. A.; Heidt, J.; Hiriart, D.; Jordan, B.; Kimeridze, G.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Kurtanidze, O. M.; Lähteenmäki, A.; Larionova, E. G.; Larionova, L. V.; Larionov, V. M.; Leto, P.; Lindfors, E.; Lin, H. C.; Morozova, D. A.; Nikolashvili, M. G.; Nilsson, K.; Oksman, M.; Roustazadeh, P.; Sievers, A.; Sigua, L. A.; Sillanpää, A.; Takahashi, T.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Troitsky, I. S.; Umana, G.; GASP-WEBT Consortium; Angelakis, E.; Krichbaum, T. P.; Nestoras, I.; Riquelme, D.; F-GAMMA; Krips, M.; Trippe, S.; Iram-PdBI; Arai, A.; Kawabata, K. S.; Sakimoto, K.; Sasada, M.; Sato, S.; Uemura, M.; Yamanaka, M.; Yoshida, M.; Kanata; Belloni, T.; Tagliaferri, G.; RXTE; Bonning, E. W.; Isler, J.; Urry, C. M.; SMARTS; Hoversten, E.; Falcone, A.; Pagani, C.; Stroh, M.; (Swift-XRT

2012-06-01

The blazar AO 0235+164 (z = 0.94) has been one of the most active objects observed by Fermi Large Area Telescope (LAT) since its launch in Summer 2008. In addition to the continuous coverage by Fermi, contemporaneous observations were carried out from the radio to γ-ray bands between 2008 September and 2009 February. In this paper, we summarize the rich multi-wavelength data collected during the campaign (including F-GAMMA, GASP-WEBT, Kanata, OVRO, RXTE, SMARTS, Swift, and other instruments), examine the cross-correlation between the light curves measured in the different energy bands, and interpret the resulting spectral energy distributions in the context of well-known blazar emission models. We find that the γ-ray activity is well correlated with a series of near-IR/optical flares, accompanied by an increase in the optical polarization degree. On the other hand, the X-ray light curve shows a distinct 20 day high state of unusually soft spectrum, which does not match the extrapolation of the optical/UV synchrotron spectrum. We tentatively interpret this feature as the bulk Compton emission by cold electrons contained in the jet, which requires an accretion disk corona with an effective covering factor of 19% at a distance of 100 R g. We model the broadband spectra with a leptonic model with external radiation dominated by the infrared emission from the dusty torus.

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.

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.

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF)

PubMed Central

Audigé, Laurent; Slongo, Theddy; Lutz, Nicolas; Blumenthal, Andrea; Joeris, Alexander

2017-01-01

Background and purpose The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF) describes the localization and morphology of fractures, and considers severity in 2 categories: (1) simple, and (2) multifragmentary. We evaluated simple and multifragmentary fractures in a large consecutive cohort of children diagnosed with long bone fractures in Switzerland. Patients and methods Children and adolescents treated for fractures between 2009 and 2011 at 2 tertiary pediatric surgery hospitals were retrospectively included. Fractures were classified according to the AO PCCF. Severity classes were described according to fracture location, patient age and sex, BMI, and cause of trauma. Results Of all trauma events, 3% (84 of 2,730) were diagnosed with a multifragmentary fracture. This proportion was age-related: 2% of multifragmentary fractures occurred in school­children and 7% occurred in adolescents. In patients diagnosed with a single fracture only, the highest percentage of multifragmentation occurred in the femur (12%, 15 of 123). In fractured paired radius/ulna bones, multifragmentation occurred in 2% (11 of 687); in fractured paired tibia/fibula bones, it occurred in 21% (24 of 115), particularly in schoolchildren (5 of 18) and adolescents (16 of 40). In a multivariable regression model, age, cause of injury, and bone were found to be relevant prognostic factors of multifragmentation (odds ratio (OR) > 2). Interpretation Overall, multifragmentation in long bone fractures in children was rare and was mostly observed in adolescents. The femur was mostly affected in single fractures and the lower leg was mostly affected in paired-bone fractures. The clinical relevance of multifragmentation regarding growth and long-term functional recovery remains to be determined. PMID:27882814

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

PubMed

Audigé, Laurent; Slongo, Theddy; Lutz, Nicolas; Blumenthal, Andrea; Joeris, Alexander

2017-04-01

Background and purpose - The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF) describes the localization and morphology of fractures, and considers severity in 2 categories: (1) simple, and (2) multifragmentary. We evaluated simple and multifragmentary fractures in a large consecutive cohort of children diagnosed with long bone fractures in Switzerland. Patients and methods - Children and adolescents treated for fractures between 2009 and 2011 at 2 tertiary pediatric surgery hospitals were retrospectively included. Fractures were classified according to the AO PCCF. Severity classes were described according to fracture location, patient age and sex, BMI, and cause of trauma. Results - Of all trauma events, 3% (84 of 2,730) were diagnosed with a multifragmentary fracture. This proportion was age-related: 2% of multifragmentary fractures occurred in school-children and 7% occurred in adolescents. In patients diagnosed with a single fracture only, the highest percentage of multifragmentation occurred in the femur (12%, 15 of 123). In fractured paired radius/ulna bones, multifragmentation occurred in 2% (11 of 687); in fractured paired tibia/fibula bones, it occurred in 21% (24 of 115), particularly in schoolchildren (5 of 18) and adolescents (16 of 40). In a multivariable regression model, age, cause of injury, and bone were found to be relevant prognostic factors of multifragmentation (odds ratio (OR) > 2). Interpretation - Overall, multifragmentation in long bone fractures in children was rare and was mostly observed in adolescents. The femur was mostly affected in single fractures and the lower leg was mostly affected in paired-bone fractures. The clinical relevance of multifragmentation regarding growth and long-term functional recovery remains to be determined.

On-sky validation of an optimal LQG control with vibration mitigation: from the CANARY Multi-Object Adaptive Optics demonstrator to the Gemini Multi-Conjugated Adaptive Optics facility.

NASA Astrophysics Data System (ADS)

Sivo, Gaetano; Kulcsár, Caroline; Conan, Jean-Marc; Raynaud, Henri-François; Gendron, Éric; Basden, Alastair; Gratadour, Damien; Morris, Tim; Petit, Cyril; Meimon, Serge; Rousset, Gérard; Garrel, Vincent; Neichel, Benoit; van Dam, Marcos; Marin, Eduardo; Carrasco, Rodrigo; Schirmer, Mischa; Rambold, William; Moreno, Cristian; Montes, Vanessa; Hardie, Kayla; Trujillo, Chad

2015-01-01

Adaptive optics provides real time correction of wavefront perturbations on ground-based telescopes and allow to reach the diffraction limit performances. Optimizing control and performance is a key issue for ever more demanding instruments on ever larger telescopes affected not only by atmospheric turbulence, but also by vibrations, windshake and tracking errors. Linear Quadratic Gaussian control achieves optimal correction when provided with a temporal model of the disturbance. We present in this paper the first on-sky results of a Kalman filter based LQG control with vibration mitigation on the CANARY instrument at the Nasmyth platform of the 4.2-m William Herschel Telescope (La Palma, Spain). The results demonstrate a clear improvement of performance for full LQG compared with standard integrator control, and assess the additional improvement brought by vibration filtering with a tip-tilt model identified from on-sky data (by 10 points of Strehl ratio), thus validating the strategy retained on the instrument SPHERE (eXtreme-AO system for extra-solar planets detection and characterization) at the VLT. The MOAO on-sky pathfinder CANARY features two AO configurations that have both been tested: single- conjugated AO and multi-object AO with NGS and NGS+ Rayleigh LGS, together with vibration mitigation on tip and tilt modes. We finally present the ongoing development done to commission such a control law on a regular Sodium laser Multi-Conjuagated Adaptive Optics (MCAO) system GeMS at the 8-m Gemini South Telescope. This implementation does not require new hardware and is already available in the real-time computer.

First detection of very-high-energy gamma-ray emission from the extreme blazar PGC 2402248 with the MAGIC telescopes

NASA Astrophysics Data System (ADS)

Mirzoyan, Razmik

2018-04-01

The MAGIC collaboration reports the first detection of very-high-energy (VHE; E > 100 GeV) gamma-ray emission from PGC 2402248, also known as 2WHSP J073326.7+515354 (Chang et al. 2016, A & A, 598, A17) with coordinates R.A.: 07:33:26.7 h, Dec: +51:53:54.99 deg. The source is classified as an extreme high-energy peaked BL Lacertae object of unknown redshift, included in the 2WHSP catalog with a synchrotron peak located at 10^17.9 Hz. PGC 2402248 was observed with the MAGIC telescopes from 2018/01/23 to 2018/04/18 (MJD 58141-58226) for about 23 h. The preliminary analysis of these data resulted in the detection of PGC 2402248 with a statistical significance of more than 6 standard deviations.

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

PubMed

Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

2017-04-01

Background and purpose - To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the upper extremities of a representative population of children classified according to the PCCF. Patients and methods - We included children and adolescents (0-17 years old) diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at the university hospitals in Bern and Lausanne (Switzerland). Patient charts were retrospectively reviewed and fractures were classified from standard radiographs. Results - Of 2,292 upper extremity fractures in 2,203 children and adolescents, 26% involved the humerus and 74% involved the forearm. In the humerus, 61%, and in the forearm, 80% of single distal fractures involved the metaphysis. In adolescents, single humerus fractures were more often epiphyseal and diaphyseal fractures, and among adolescents radius fractures were more often epiphyseal fractures than in other age groups. 47% of combined forearm fractures were distal metaphyseal fractures. Only 0.7% of fractures could not be classified within 1 of the child-specific fracture patterns. Of the single epiphyseal fractures, 49% were Salter-Harris type-II (SH II) fractures; of these, 94% occurred in schoolchildren and adolescents. Of the metaphyseal fractures, 58% showed an incomplete fracture pattern. 89% of incomplete fractures affected the distal radius. Of the diaphyseal fractures, 32% were greenstick fractures. 24 Monteggia fractures occurred in pre-school children and schoolchildren, and 2 occurred in adolescents. Interpretation - The pattern of pediatric fractures in the upper extremity can be comprehensively described according to the PCCF. Prospective clinical studies are needed to determine its clinical relevance for treatment decisions and

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

PubMed

Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

2017-04-01

Background and purpose - To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the lower extremities of a representative population of children classified according to the PCCF. Patients and methods - We included patients up to the age of 17 who were diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at either of 2 tertiary care university hospitals in Switzerland. Patient charts were retrospectively reviewed. Results - More lower extremity fractures occurred in boys (62%, n = 341). Of 548 fractured long bones in the lower extremity, 25% involved the femur and 75% the lower leg. The older the patients, the more combined fractures of the tibia and fibula were sustained (adolescents: 50%, 61 of 123). Salter-Harris (SH) fracture patterns represented 66% of single epiphyseal fractures (83 of 126). Overall, 74 of the 83 SH patterns occurred in the distal epiphysis. Of all the metaphyseal fractures, 74 of 79 were classified as incomplete or complete. Complete oblique spiral fractures accounted for 57% of diaphyseal fractures (120 of 211). Of all fractures, 7% (40 of 548) were classified in the category "other", including 29 fractures that were identified as toddler's fractures. 5 combined lower leg fractures were reported in the proximal metaphysis, 40 in the diaphysis, 26 in the distal metaphysis, and 8 in the distal epiphysis. Interpretation - The PCCF allows classification of lower extremity fracture patterns in the clinical setting. Re-introduction of a specific code for toddler's fractures in the PCCF should be considered.

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF)

PubMed Central

Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

2017-01-01

Background and purpose To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the lower extremities of a representative population of children classified according to the PCCF. Patients and methods We included patients up to the age of 17 who were diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at either of 2 tertiary care university hospitals in Switzerland. Patient charts were retrospectively reviewed. Results More lower extremity fractures occurred in boys (62%, n = 341). Of 548 fractured long bones in the lower extremity, 25% involved the femur and 75% the lower leg. The older the patients, the more combined fractures of the tibia and fibula were sustained (adolescents: 50%, 61 of 123). Salter-Harris (SH) fracture patterns represented 66% of single epiphyseal fractures (83 of 126). Overall, 74 of the 83 SH patterns occurred in the distal epiphysis. Of all the metaphyseal fractures, 74 of 79 were classified as incomplete or complete. Complete oblique spiral fractures accounted for 57% of diaphyseal fractures (120 of 211). Of all fractures, 7% (40 of 548) were classified in the category "other", including 29 fractures that were identified as toddler’s fractures. 5 combined lower leg fractures were reported in the proximal metaphysis, 40 in the diaphysis, 26 in the distal metaphysis, and 8 in the distal epiphysis. Interpretation The PCCF allows classification of lower extremity fracture patterns in the clinical setting. Re-introduction of a specific code for toddler’s fractures in the PCCF should be considered. PMID:27882811

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF)

PubMed Central

Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

2017-01-01

Background and purpose To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the upper extremities of a representative population of children classified according to the PCCF. Patients and methods We included children and adolescents (0–17 years old) diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at the university hospitals in Bern and Lausanne (Switzerland). Patient charts were retrospectively reviewed and fractures were classified from standard radiographs. Results Of 2,292 upper extremity fractures in 2,203 children and adolescents, 26% involved the humerus and 74% involved the forearm. In the humerus, 61%, and in the forearm, 80% of single distal fractures involved the metaphysis. In adolescents, single humerus fractures were more often epiphyseal and diaphyseal fractures, and among adolescents radius fractures were more often epiphyseal fractures than in other age groups. 47% of combined forearm fractures were distal metaphyseal fractures. Only 0.7% of fractures could not be classified within 1 of the child-specific fracture patterns. Of the single epiphyseal fractures, 49% were Salter-Harris type-II (SH II) fractures; of these, 94% occurred in schoolchildren and adolescents. Of the metaphyseal fractures, 58% showed an incomplete fracture pattern. 89% of incomplete fractures affected the distal radius. Of the diaphyseal fractures, 32% were greenstick fractures. 24 Monteggia fractures occurred in pre-school children and schoolchildren, and 2 occurred in adolescents. Interpretation The pattern of pediatric fractures in the upper extremity can be comprehensively described according to the PCCF. Prospective clinical studies are needed to determine its clinical relevance for treatment decisions and prognostication

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. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Multi-wavelength observations of blazar AO 0235+164 in the 2008-2009 flaring state

DOE PAGES

Ackermann, M.; Ajello, M.; Ballet, J.; ...

2012-05-17

The blazar AO 0235+164 (z = 0.94) has been one of the most active objects observed by Fermi Large Area Telescope (LAT) since its launch in Summer 2008. In addition to the continuous coverage by Fermi, contemporaneous observations were carried out from the radio to γ-ray bands between 2008 September and 2009 February.Here, we summarize the rich multi-wavelength data collected during the campaign (including F-GAMMA, GASP-WEBT, Kanata, OVRO, RXTE, SMARTS, Swift, and other instruments), examine the cross-correlation between the light curves measured in the different energy bands, and interpret the resulting spectral energy distributions in the context of well-known blazarmore » emission models. We also find that the γ-ray activity is well correlated with a series of near-IR/optical flares, accompanied by an increase in the optical polarization degree. On the other hand, the X-ray light curve shows a distinct 20 day high state of unusually soft spectrum, which does not match the extrapolation of the optical/UV synchrotron spectrum. We tentatively interpret this feature as the bulk Compton emission by cold electrons contained in the jet, which requires an accretion disk corona with an effective covering factor of 19% at a distance of 100 R g. Finally, we model the broadband spectra with a leptonic model with external radiation dominated by the infrared emission from the dusty torus.« less

Data General Corporation Advanced Operating System/Virtual Storage (AOS/ VS). Revision 7.60

DTIC Science & Technology

1989-02-22

control list for each directory and data file. An access control list includes the users who can and cannot access files as well as the access...and any required data, it can -5- February 22, 1989 Final Evaluation Report Data General AOS/VS SYSTEM OVERVIEW operate asynchronously and in parallel...memory. The IOC can perform the data transfer without further interventiin from the CPU. The I/O channels interface with the processor or system

Enhanced X-ray Activity of the UHBL Source 1ES 0033+595

NASA Astrophysics Data System (ADS)

Kapanadze, Bidzina

2018-04-01

The TeV-detected ultra-high-energy peaked BL Lacertae source (UHBL) 1ES 0033+595 was observed 87 times with X-Ray Telescope (XRT) onboard the Neil Geherels Swift Observatory since 2005 April 1 with a total exposure of 117 ks (Mostly, in the framework of our ToO requests).

Parasitic helminths of reptiles (Reptilia) in South Moravia (Czech Republic).

PubMed

Borkovcová, M; Kopriva, J

2005-01-01

An helminthological investigation of 104 reptile species was carried out in south Moravia (Czech Republic). We examined Lacerta viridis, L. agilis, Anguis fragilis, Natrix natrix, Coronella austriaca and Vipera berus. Twelve species of parasites were found. Among these, Nematoda occurred most often, followed by Trematoda and Cestoda. No Acanthocephala were detected.

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.

Object-processing neural efficiency differentiates object from spatial visualizers.

PubMed

Motes, Michael A; Malach, Rafael; Kozhevnikov, Maria

2008-11-19

The visual system processes object properties and spatial properties in distinct subsystems, and we hypothesized that this distinction might extend to individual differences in visual processing. We conducted a functional MRI study investigating the neural underpinnings of individual differences in object versus spatial visual processing. Nine participants of high object-processing ability ('object' visualizers) and eight participants of high spatial-processing ability ('spatial' visualizers) were scanned, while they performed an object-processing task. Object visualizers showed lower bilateral neural activity in lateral occipital complex and lower right-lateralized neural activity in dorsolateral prefrontal cortex. The data indicate that high object-processing ability is associated with more efficient use of visual-object resources, resulting in less neural activity in the object-processing pathway.

The subjective experience of object recognition: comparing metacognition for object detection and object categorization.

PubMed

Meuwese, Julia D I; van Loon, Anouk M; Lamme, Victor A F; Fahrenfort, Johannes J

2014-05-01

Perceptual decisions seem to be made automatically and almost instantly. Constructing a unitary subjective conscious experience takes more time. For example, when trying to avoid a collision with a car on a foggy road you brake or steer away in a reflex, before realizing you were in a near accident. This subjective aspect of object recognition has been given little attention. We used metacognition (assessed with confidence ratings) to measure subjective experience during object detection and object categorization for degraded and masked objects, while objective performance was matched. Metacognition was equal for degraded and masked objects, but categorization led to higher metacognition than did detection. This effect turned out to be driven by a difference in metacognition for correct rejection trials, which seemed to be caused by an asymmetry of the distractor stimulus: It does not contain object-related information in the detection task, whereas it does contain such information in the categorization task. Strikingly, this asymmetry selectively impacted metacognitive ability when objective performance was matched. This finding reveals a fundamental difference in how humans reflect versus act on information: When matching the amount of information required to perform two tasks at some objective level of accuracy (acting), metacognitive ability (reflecting) is still better in tasks that rely on positive evidence (categorization) than in tasks that rely more strongly on an absence of evidence (detection).

CLUSTER GLIMPSES WITH RAVEN: AO-CORRECTED NEAR AND MID-INFRARED IMAGES OF GLIMPSE C01 AND GLIMPSE C02

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davidge, T. J.; Andersen, D. R.; Lardière, O., E-mail: tim.davidge@nrc.ca, E-mail: david.andersen@nrc.ca, E-mail: lardiere@uvic.ca

We discuss images of the star clusters GLIMPSE C01 (GC01) and GLIMPSE C02 (GC02) that were recorded with the Subaru IRCS. Distortions in the wavefront were corrected with the RAVEN adaptive optics (AO) science demonstrator, allowing individual stars in the central regions of both clusters—where the fractional contamination from non-cluster objects is lowest—to be imaged. In addition to J , H , and K ′ images, both clusters were observed through a narrow-band filter centered near 3.05 μ m; GC01 was also observed through two other narrow-band filters that sample longer wavelengths. Stars in the narrow-band images have an FWHMmore » that is close to the telescope diffraction limit, demonstrating that open-loop AO systems like RAVEN can deliver exceptional image quality. The near-infrared color–magnitude diagram of GC01 is smeared by non-uniform extinction with a 1 σ dispersion Δ A{sub K}  = ±0.13 mag. Spatial variations in A{sub K} are not related in a systematic way to location in the field. The Red Clump is identified in the K luminosity function (LF) of GC01, and a distance modulus of 13.6 is found. The K LF of GC01 is consistent with a system that is dominated by stars with an age >1 Gyr. As for GC02, the K LF is flat for K  > 16, and the absence of a sub-giant branch argues against an old age if the cluster is at a distance of ∼7 kpc. Archival SPITZER [3.6] and [4.5] images of the clusters are also examined, and the red giant branch-tip is identified. It is demonstrated in the Appendix that the [3.6] surface brightness profiles of both clusters can be traced out to radii of at least 100 arcsec.« less

Sea-level history of past interglacial periods: New evidence from uranium-series dating of corals from Curaçao, Leeward Antilles islands

USGS Publications Warehouse

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

2012-01-01

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.

Object-based warping: an illusory distortion of space within objects.

PubMed

Vickery, Timothy J; Chun, Marvin M

2010-12-01

Visual objects are high-level primitives that are fundamental to numerous perceptual functions, such as guidance of attention. We report that objects warp visual perception of space in such a way that spatial distances within objects appear to be larger than spatial distances in ground regions. When two dots were placed inside a rectangular object, they appeared farther apart from one another than two dots with identical spacing outside of the object. To investigate whether this effect was object based, we measured the distortion while manipulating the structure surrounding the dots. Object displays were constructed with a single object, multiple objects, a partially occluded object, and an illusory object. Nonobject displays were constructed to be comparable to object displays in low-level visual attributes. In all cases, the object displays resulted in a more powerful distortion of spatial perception than comparable non-object-based displays. These results suggest that perception of space within objects is warped.

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.

Object Manipulation Facilitates Kind-Based Object Individuation of Shape-Similar Objects

ERIC Educational Resources Information Center

Kingo, Osman S.; Krojgaard, Peter

2011-01-01

Five experiments investigated the importance of shape and object manipulation when 12-month-olds were given the task of individuating objects representing exemplars of kinds in an event-mapping design. In Experiments 1 and 2, results of the study from Xu, Carey, and Quint (2004, Experiment 4) were partially replicated, showing that infants were…

Organizing and Typing Persistent Objects Within an Object-Oriented Framework

NASA Technical Reports Server (NTRS)

Madany, Peter W.; Campbell, Roy H.

1991-01-01

Conventional operating systems provide little or no direct support for the services required for an efficient persistent object system implementation. We have built a persistent object scheme using a customization and extension of an object-oriented operating system called Choices. Choices includes a framework for the storage of persistent data that is suited to the construction of both conventional file system and persistent object system. In this paper we describe three areas in which persistent object support differs from file system support: storage organization, storage management, and typing. Persistent object systems must support various sizes of objects efficiently. Customizable containers, which are themselves persistent objects and can be nested, support a wide range of object sizes in Choices. Collections of persistent objects that are accessed as an aggregate and collections of light-weight persistent objects can be clustered in containers that are nested within containers for larger objects. Automated garbage collection schemes are added to storage management and have a major impact on persistent object applications. The Choices persistent object store provides extensible sets of persistent object types. The store contains not only the data for persistent objects but also the names of the classes to which they belong and the code for the operation of the classes. Besides presenting persistent object storage organization, storage management, and typing, this paper discusses how persistent objects are named and used within the Choices persistent data/file system framework.

Object-based attention: strength of object representation and attentional guidance.

PubMed

Shomstein, Sarah; Behrmann, Marlene

2008-01-01

Two or more features belonging to a single object are identified more quickly and more accurately than are features belonging to different objects--a finding attributed to sensory enhancement of all features belonging to an attended or selected object. However, several recent studies have suggested that this "single-object advantage" may be a product of probabilistic and configural strategic prioritizations rather than of object-based perceptual enhancement per se, challenging the underlying mechanism that is thought to give rise to object-based attention. In the present article, we further explore constraints on the mechanisms of object-based selection by examining the contribution of the strength of object representations to the single-object advantage. We manipulated factors such as exposure duration (i.e., preview time) and salience of configuration (i.e., objects). Varying preview time changes the magnitude of the object-based effect, so that if there is ample time to establish an object representation (i.e., preview time of 1,000 msec), then both probability and configuration (i.e., objects) guide attentional selection. If, however, insufficient time is provided to establish a robust object-based representation, then only probabilities guide attentional selection. Interestingly, at a short preview time of 200 msec, when the two objects were sufficiently different from each other (i.e., different colors), both configuration and probability guided attention selection. These results suggest that object-based effects can be explained both in terms of strength of object representations (established at longer exposure durations and by pictorial cues) and probabilistic contingencies in the visual environment.

The MagAO Giant Accreting Protoplanet Survey (GAPlanetS): Recent Results

NASA Astrophysics Data System (ADS)

Follette, Katherine; Close, Laird; Males, Jared; Morzinski, Katie; Leonard, Clare; MagAO

2018-01-01

I will summarize recent results of the MagAO Giant Accreting Protoplant Survey (GAPlanetS), a search for accreting protoplanets at H-alpha inside of transitional disk gaps. These young, centrally-cleared circumstellar disks are often hosted by stars that are still actively accreting, making it likely that any planets that lie in their central cavities will also be actively accreting. Through differential imaging at Hydrogen-alpha using Magellan's visible light adaptive optics system, we have completed the first systematic search for H-alpha emission from accreting protoplanets in fifteen bright Southern hemisphere transitional disks. I will present results from this survey, including a second epoch on the LkCa 15 system that shows several accreting protoplanet candidates.

Underground structure pattern and multi AO reaction with step feed concept for upgrading an large wastewater treatment plant

NASA Astrophysics Data System (ADS)

Peng, Yi; Zhang, Jie; Li, Dong

2018-03-01

A large wastewater treatment plant (WWTP) could not meet the new demand of urban environment and the need of reclaimed water in China, using a US treatment technology. Thus a multi AO reaction process (Anaerobic/oxic/anoxic/oxic/anoxic/oxic) WWTP with underground structure was proposed to carry out the upgrade project. Four main new technologies were applied: (1) multi AO reaction with step feed technology; (2) deodorization; (3) new energy-saving technology such as water resource heat pump and optical fiber lighting system; (4) dependable old WWTP’s water quality support measurement during new WWTP’s construction. After construction, upgrading WWTP had saved two thirds land occupation, increased 80% treatment capacity and improved effluent standard by more than two times. Moreover, it had become a benchmark of an ecological negative capital changing to a positive capital.

The Discovery of a High-Redshift Quasar without Emission Lines from Sloan Digital Sky Survey Commissioning Data.

PubMed

Fan; Strauss; Gunn; Lupton; Carilli; Rupen; Schmidt; Moustakas; Davis; Annis; Bahcall; Brinkmann; Brunner; Csabai; Doi; Fukugita; Heckman; Hennessy; Hindsley; Ivezic; Knapp; Lamb; Munn; Pauls; Pier; Rockosi; Schneider; Szalay; Tucker; York

1999-12-01

We report observations of a luminous unresolved object at redshift z=4.62, with a featureless optical spectrum redward of the Lyalpha forest region, discovered from Sloan Digital Sky Survey commissioning data. The redshift is determined by the onset of the Lyalpha forest at lambda approximately 6800 Å and a Lyman limit system at lambda=5120 Å. A strong Lyalpha absorption system with weak metal absorption lines at z=4.58 is also identified in the spectrum. The object has a continuum absolute magnitude of -26.6 at 1450 Å in the rest frame (h0=0.5, q0=0.5) and therefore cannot be an ordinary galaxy. It shows no radio emission (the 3 sigma upper limit of its flux at 6 cm is 60 µJy), indicating a radio-to-optical flux ratio at least as small as that of the radio-weakest BL Lacertae objects known. It is also not linearly polarized to a 3 sigma upper limit of 4% in the observed I band. Therefore, it is either the most distant BL Lac object known to date, with very weak radio emission, or a new type of unbeamed quasar, whose broad emission line region is very weak or absent.

Object locating system

DOEpatents

Novak, J.L.; Petterson, B.

1998-06-09

A sensing system locates an object by sensing the object`s effect on electric fields. The object`s effect on the mutual capacitance of electrode pairs varies according to the distance between the object and the electrodes. A single electrode pair can sense the distance from the object to the electrodes. Multiple electrode pairs can more precisely locate the object in one or more dimensions. 12 figs.

AoAtg26, a putative sterol glucosyltransferase, is required for autophagic degradation of peroxisomes, mitochondria, and nuclei in the filamentous fungus Aspergillus oryzae.

PubMed

Kikuma, Takashi; Tadokoro, Takayuki; Maruyama, Jun-Ichi; Kitamoto, Katsuhiko

2017-02-01

Autophagy is a conserved process in eukaryotic cells for degradation of cellular proteins and organelles. In filamentous fungi, autophagic degradation of organelles such as peroxisomes, mitochondria, and nuclei occurs in basal cells after the prolonged culture, but its mechanism is not well understood. Here, we functionally analyzed the filamentous fungus Aspergillus oryzae AoAtg26, an ortholog of the sterol glucosyltransferase PpAtg26 involved in pexophagy in the yeast Pichia pastoris. Deletion of Aoatg26 caused a severe decrease in conidiation and aerial hyphae formation, which is typically observed in the autophagy-deficient A. oryzae strains. In addition, cup-shaped AoAtg8-positive membrane structures were accumulated in the Aoatg26 deletion strain, indicating that autophagic process is impaired. Indeed, the Aoatg26 deletion strain was defective in the degradation of peroxisomes, mitochondria, and nuclei. Taken together, AoAtg26 plays an important role for autophagic degradation of organelles in A. oryzae, which may physiologically contribute to the differentiation in filamentous fungi.

Development of binary image masks for TPF-C and ground-based AO coronagraphs

NASA Astrophysics Data System (ADS)

Ge, Jian; Crepp, Justin; Vanden Heuvel, Andrew; Miller, Shane; McDavitt, Dan; Kravchenko, Ivan; Kuchner, Marc

2006-06-01

We report progress on the development of precision binary notch-filter focal plane coronagraphic masks for directly imaging Earth-like planets at visible wavelengths with the Terrestrial Planet Finder Coronagraph (TPF-C), and substellar companions at near infrared wavelengths from the ground with coronagraphs coupled to high-order adaptive optics (AO) systems. Our recent theoretical studies show that 8th-order image masks (Kuchner, Crepp & Ge 2005, KCG05) are capable of achieving unlimited dynamic range in an ideal optical system, while simultaneously remaining relatively insensitive to low-spatial-frequency optical aberrations, such as tip/tilt errors, defocus, coma, astigmatism, etc. These features offer a suite of advantages for the TPF-C by relaxing many control and stability requirements, and can also provide resistance to common practical problems associated with ground-based observations; for example, telescope flexure and low-order errors left uncorrected by the AO system due to wavefront sensor-deformable mirror lag time can leak light at significant levels. Our recent lab experiments show that prototype image masks can generate contrast levels on the order of 2x10 -6 at 3 λ/D and 6x10 -7 at 10 λ/D without deformable mirror correction using monochromatic light (Crepp et al. 2006), and that this contrast is limited primarily by light scattered by imperfections in the optics and extra diffraction created by mask construction errors. These experiments also indicate that the tilt and defocus sensitivities of high-order masks follow the theoretical predictions of Shaklan and Green 2005. In this paper, we discuss these topics as well as review our progress on developing techniques for fabricating a new series of image masks that are "free-standing", as such construction designs may alleviate some of the (mostly chromatic) problems associated with masks that rely on glass substrates for mechanical support. Finally, results obtained from our AO coronagraph

Direct hip joint distraction during acetabular fracture surgery using the AO universal manipulator.

PubMed

Calafi, L Afshin; Routt, M L Chip

2010-02-01

Certain acetabular fractures may necessitate distraction of the hip joint for removal of intra-articular debris and assessment of reduction. Distraction can be accomplished by manual traction, using a traction table or an AO universal manipulator (UM). The UM is a relatively simple and an inexpensive device that can provide focal distraction in a controlled manner without the risks associated with the use of a traction table. We describe a technique using the UM for hip joint distraction during acetabular fracture surgery through a Kocher-Langenbeck surgical exposure.

Diffraction-limited Visible Light Images of Orion Trapezium Cluster with the Magellan Adaptive Secondary Adaptive Optics System (MagAO)

NASA Astrophysics Data System (ADS)

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

2013-09-01

We utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high spatial resolution observations in "visible light" with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.''5-0.''7), we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60 s) r' (0.63 μm) images are slightly coarser at FWHM = 23-29 mas (Strehl ~28%) with bright (R < 9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young (~1 Myr) Orion Trapezium θ1 Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary θ1 Ori C 1 C 2 was easily resolved in non-interferometric images for the first time. The relative positions of the bright trapezium binary stars were measured with ~0.6-5 mas accuracy. We are now sensitive to relative proper motions of just ~0.2 mas yr-1 (~0.4 km s-1 at 414 pc)—this is a ~2-10 × improvement in orbital velocity accuracy compared to previous efforts. For the first time, we see clear motion of the barycenter of θ1 Ori B 2 B 3 about θ1 Ori B 1. All five members of the θ1 Ori B system appear likely to be a gravitationally bound "mini cluster," but we find that not all the orbits can be both circular and co-planar. The lowest mass member of the θ1 Ori B system (B 4; mass ~0.2 M ⊙) has a very clearly detected motion (at 4.1 ± 1.3 km s-1 correlation = 99.9%) w.r.t. B 1. Previous work has suggested that B 4 and B 3 are on long-term unstable orbits and will be ejected from this "mini cluster." However, our new "baseline" model of the θ1 Ori B system suggests a more hierarchical system than previously thought, and so the ejection of B 4 may not occur for many orbits, and B 3 may be stable against ejection in the long-term. This "ejection" process of the lowest mass member of a "mini cluster" could play a major role in the formation of

DIFFRACTION-LIMITED VISIBLE LIGHT IMAGES OF ORION TRAPEZIUM CLUSTER WITH THE MAGELLAN ADAPTIVE SECONDARY ADAPTIVE OPTICS SYSTEM (MagAO)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Close, L. M.; Males, J. R.; Morzinski, K.

2013-09-10

We utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high spatial resolution observations in ''visible light'' with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.''5-0.''7), we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60 s) r' (0.63 {mu}m) images are slightly coarser at FWHM = 23-29 mas (Strehl {approx}28%) with bright (R < 9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young ({approx}1 Myr) Orion Trapezium {theta}{sup 1}more » Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary {theta}{sup 1} Ori C{sub 1} C{sub 2} was easily resolved in non-interferometric images for the first time. The relative positions of the bright trapezium binary stars were measured with {approx}0.6-5 mas accuracy. We are now sensitive to relative proper motions of just {approx}0.2 mas yr{sup -1} ({approx}0.4 km s{sup -1} at 414 pc)-this is a {approx}2-10 Multiplication-Sign improvement in orbital velocity accuracy compared to previous efforts. For the first time, we see clear motion of the barycenter of {theta}{sup 1} Ori B{sub 2} B{sub 3} about {theta}{sup 1} Ori B{sub 1}. All five members of the {theta}{sup 1} Ori B system appear likely to be a gravitationally bound ''mini cluster'', but we find that not all the orbits can be both circular and co-planar. The lowest mass member of the {theta}{sup 1} Ori B system (B{sub 4}; mass {approx}0.2 M{sub Sun }) has a very clearly detected motion (at 4.1 {+-} 1.3 km s{sup -1}; correlation = 99.9%) w.r.t. B{sub 1}. Previous work has suggested that B{sub 4} and B{sub 3} are on long-term unstable orbits and will be ejected from this ''mini cluster''. However, our new ''baseline'' model of the {theta}{sup 1} Ori B system suggests a more hierarchical system than previously thought

Robo-AO Kepler Planetary Candidate Survey. III. Adaptive Optics Imaging of 1629 Kepler Exoplanet Candidate Host Stars

NASA Astrophysics Data System (ADS)

Ziegler, Carl; Law, Nicholas M.; Morton, Tim; Baranec, Christoph; Riddle, Reed; Atkinson, Dani; Baker, Anna; Roberts, Sarah; Ciardi, David R.

2017-02-01

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. In this paper, we present the results of our search for stars nearby 1629 Kepler planet candidate hosts. With survey sensitivity to objects as close as ˜0.″15, and magnitude differences Δm ≤slant 6, we find 223 stars in the vicinity of 206 target KOIs; 209 of these nearby stars have not been previously imaged in high resolution. We measure an overall nearby-star probability for Kepler planet candidates of 12.6 % +/- 0.9 % at separations between 0.″15 and 4.″0. Particularly interesting KOI systems are discussed, including 26 stars with detected companions that host rocky, habitable zone candidates and five new candidate planet-hosting quadruple star systems. We explore the broad correlations between planetary systems and stellar binarity, using the combined data set of Baranec et al. and this paper. Our previous 2σ result of a low detected nearby star fraction of KOIs hosting close-in giant planets is less apparent in this larger data set. We also find a significant correlation between detected nearby star fraction and KOI number, suggesting possible variation between early and late Kepler data releases.

The influence of object similarity and orientation on object-based cueing.

PubMed

Hein, Elisabeth; Blaschke, Stefan; Rolke, Bettina

2017-01-01

Responses to targets that appear at a noncued position within the same object (invalid-same) compared to a noncued position at an equidistant different object (invalid-different) tend to be faster and more accurate. These cueing effects have been taken as evidence that visual attention can be object based (Egly, Driver, & Rafal, Journal of Experimental Psychology: General, 123, 161-177, 1994). Recent findings, however, have shown that the object-based cueing effect is influenced by object orientation, suggesting that the cueing effect might be due to a more general facilitation of attentional shifts across the horizontal meridian (Al-Janabi & Greenberg, Attention, Perception, & Psychophysics, 1-17, 2016; Pilz, Roggeveen, Creighton, Bennet, & Sekuler, PLOS ONE, 7, e30693, 2012). The aim of this study was to investigate whether the object-based cueing effect is influenced by object similarity and orientation. According to the object-based attention account, objects that are less similar to each other should elicit stronger object-based cueing effects independent of object orientation, whereas the horizontal meridian theory would not predict any effect of object similarity. We manipulated object similarity by using a color (Exp. 1, Exp. 2A) or shape change (Exp. 2B) to distinguish two rectangles in a variation of the classic two-rectangle paradigm (Egly et al., 1994). We found that the object-based cueing effects were influenced by the orientation of the rectangles and strengthened by object dissimilarity. We suggest that object-based cueing effects are strongly affected by the facilitation of attention along the horizontal meridian, but that they also have an object-based attentional component, which is revealed when the dissimilarity between the presented objects is accentuated.

Object locating system

DOEpatents

Novak, James L.; Petterson, Ben

1998-06-09

A sensing system locates an object by sensing the object's effect on electric fields. The object's effect on the mutual capacitance of electrode pairs varies according to the distance between the object and the electrodes. A single electrode pair can sense the distance from the object to the electrodes. Multiple electrode pairs can more precisely locate the object in one or more dimensions.

Binary Classification of an Unknown Object through Atmospheric Turbulence Using a Polarimetric Blind-Deconvolution Algorithm Augmented with Adaptive Degree of Linear Polarization Priors

DTIC Science & Technology

2012-03-01

geometry of reflection from a smooth (or mirror-like) surface [27]. In passive polarimetry , the angle of polarization (AoP) provides information about... polarimetry for remote sens- ing applications”. Appl. Opt., 45(22):5453–5469, Aug 2006. URL http://ao.osa.org/abstract.cfm?URI=ao-45-22-5453. 27

Object formation in visual working memory: Evidence from object-based attention.

PubMed

Zhou, Jifan; Zhang, Haihang; Ding, Xiaowei; Shui, Rende; Shen, Mowei

2016-09-01

We report on how visual working memory (VWM) forms intact perceptual representations of visual objects using sub-object elements. Specifically, when objects were divided into fragments and sequentially encoded into VWM, the fragments were involuntarily integrated into objects in VWM, as evidenced by the occurrence of both positive and negative object-based attention effects: In Experiment 1, when subjects' attention was cued to a location occupied by the VWM object, the target presented at the location of that object was perceived as occurring earlier than that presented at the location of a different object. In Experiment 2, responses to a target were significantly slower when a distractor was presented at the same location as the cued object (Experiment 2). These results suggest that object fragments can be integrated into objects within VWM in a manner similar to that of visual perception. Copyright © 2016 Elsevier B.V. All rights reserved.

Experience with Malleable Objects Influences Shape-based Object Individuation by Infants

PubMed Central

Woods, Rebecca J.; Schuler, Jena

2014-01-01

Infants’ ability to accurately represent and later recognize previously viewed objects, and conversely, to discriminate novel objects from those previously seen improves remarkably over the first two years of life. During this time, infants acquire extensive experience viewing and manipulating objects and these experiences influence their physical reasoning. Here we posited that infants’ observations of object feature stability (rigid versus malleable) can influence use of those features to individuate two successively viewed objects. We showed 8.5-month-olds a series of objects that could or could not change shape then assessed their use of shape as a basis for object individuation. Infants who explored rigid objects later used shape differences to individuate objects; however, infants who explored malleable objects did not. This outcome suggests that the latter infants did not take into account shape differences during the physical reasoning task and provides further evidence that infants’ attention to object features can be readily modified based on recent experiences. PMID:24561541

Effects of Selected Object Characteristics on Object Permanence Test Performance.

ERIC Educational Resources Information Center

Lingle, Kathleen M.; Lingle, John H.

A study was conducted to investigate the degree to which both object familiarity and motivational factors influence infants' search behavior in an object permanence test. Infants' search behavior for an unfamiliar test object was compared with search behavior for (a) an experientially familiar object that each infant had played with daily for a…

Real Objects Can Impede Conditional Reasoning but Augmented Objects Do Not.

PubMed

Sato, Yuri; Sugimoto, Yutaro; Ueda, Kazuhiro

2018-03-01

In this study, Knauff and Johnson-Laird's (2002) visual impedance hypothesis (i.e., mental representations with irrelevant visual detail can impede reasoning) is applied to the domain of external representations and diagrammatic reasoning. We show that the use of real objects and augmented real (AR) objects can control human interpretation and reasoning about conditionals. As participants made inferences (e.g., an invalid one from "if P then Q" to "P"), they also moved objects corresponding to premises. Participants who moved real objects made more invalid inferences than those who moved AR objects and those who did not manipulate objects (there was no significant difference between the last two groups). Our results showed that real objects impeded conditional reasoning, but AR objects did not. These findings are explained by the fact that real objects may over-specify a single state that exists, while AR objects suggest multiple possibilities. Copyright © 2017 Cognitive Science Society, Inc.

Orientation congruency effects for familiar objects: coordinate transformations in object recognition.

PubMed

Graf, M; Kaping, D; Bülthoff, H H

2005-03-01

How do observers recognize objects after spatial transformations? Recent neurocomputational models have proposed that object recognition is based on coordinate transformations that align memory and stimulus representations. If the recognition of a misoriented object is achieved by adjusting a coordinate system (or reference frame), then recognition should be facilitated when the object is preceded by a different object in the same orientation. In the two experiments reported here, two objects were presented in brief masked displays that were in close temporal contiguity; the objects were in either congruent or incongruent picture-plane orientations. Results showed that naming accuracy was higher for congruent than for incongruent orientations. The congruency effect was independent of superordinate category membership (Experiment 1) and was found for objects with different main axes of elongation (Experiment 2). The results indicate congruency effects for common familiar objects even when they have dissimilar shapes. These findings are compatible with models in which object recognition is achieved by an adjustment of a perceptual coordinate system.

Creating Objects and Object Categories for Studying Perception and Perceptual Learning

PubMed Central

Hauffen, Karin; Bart, Eugene; Brady, Mark; Kersten, Daniel; Hegdé, Jay

2012-01-01

In order to quantitatively study object perception, be it perception by biological systems or by machines, one needs to create objects and object categories with precisely definable, preferably naturalistic, properties1. Furthermore, for studies on perceptual learning, it is useful to create novel objects and object categories (or object classes) with such properties2. Many innovative and useful methods currently exist for creating novel objects and object categories3-6 (also see refs. 7,8). However, generally speaking, the existing methods have three broad types of shortcomings. First, shape variations are generally imposed by the experimenter5,9,10, and may therefore be different from the variability in natural categories, and optimized for a particular recognition algorithm. It would be desirable to have the variations arise independently of the externally imposed constraints. Second, the existing methods have difficulty capturing the shape complexity of natural objects11-13. If the goal is to study natural object perception, it is desirable for objects and object categories to be naturalistic, so as to avoid possible confounds and special cases. Third, it is generally hard to quantitatively measure the available information in the stimuli created by conventional methods. It would be desirable to create objects and object categories where the available information can be precisely measured and, where necessary, systematically manipulated (or 'tuned'). This allows one to formulate the underlying object recognition tasks in quantitative terms. Here we describe a set of algorithms, or methods, that meet all three of the above criteria. Virtual morphogenesis (VM) creates novel, naturalistic virtual 3-D objects called 'digital embryos' by simulating the biological process of embryogenesis14. Virtual phylogenesis (VP) creates novel, naturalistic object categories by simulating the evolutionary process of natural selection9,12,13. Objects and object categories created

Creating objects and object categories for studying perception and perceptual learning.

PubMed

Hauffen, Karin; Bart, Eugene; Brady, Mark; Kersten, Daniel; Hegdé, Jay

2012-11-02

In order to quantitatively study object perception, be it perception by biological systems or by machines, one needs to create objects and object categories with precisely definable, preferably naturalistic, properties. Furthermore, for studies on perceptual learning, it is useful to create novel objects and object categories (or object classes) with such properties. Many innovative and useful methods currently exist for creating novel objects and object categories (also see refs. 7,8). However, generally speaking, the existing methods have three broad types of shortcomings. First, shape variations are generally imposed by the experimenter, and may therefore be different from the variability in natural categories, and optimized for a particular recognition algorithm. It would be desirable to have the variations arise independently of the externally imposed constraints. Second, the existing methods have difficulty capturing the shape complexity of natural objects. If the goal is to study natural object perception, it is desirable for objects and object categories to be naturalistic, so as to avoid possible confounds and special cases. Third, it is generally hard to quantitatively measure the available information in the stimuli created by conventional methods. It would be desirable to create objects and object categories where the available information can be precisely measured and, where necessary, systematically manipulated (or 'tuned'). This allows one to formulate the underlying object recognition tasks in quantitative terms. Here we describe a set of algorithms, or methods, that meet all three of the above criteria. Virtual morphogenesis (VM) creates novel, naturalistic virtual 3-D objects called 'digital embryos' by simulating the biological process of embryogenesis. Virtual phylogenesis (VP) creates novel, naturalistic object categories by simulating the evolutionary process of natural selection. Objects and object categories created by these simulations can

Learning Object Repositories

ERIC Educational Resources Information Center

Lehman, Rosemary

2007-01-01

This chapter looks at the development and nature of learning objects, meta-tagging standards and taxonomies, learning object repositories, learning object repository characteristics, and types of learning object repositories, with type examples. (Contains 1 table.)

Young Children's Self-Generated Object Views and Object Recognition

ERIC Educational Resources Information Center

James, Karin H.; Jones, Susan S.; Smith, Linda B.; Swain, Shelley N.

2014-01-01

Two important and related developments in children between 18 and 24 months of age are the rapid expansion of object name vocabularies and the emergence of an ability to recognize objects from sparse representations of their geometric shapes. In the same period, children also begin to show a preference for planar views (i.e., views of objects held…

Conceptual Coherence Affects Phonological Activation of Context Objects during Object Naming

ERIC Educational Resources Information Center

Oppermann, Frank; Jescheniak, Jorg D.; Schriefers, Herbert

2008-01-01

In 4 picture-word interference experiments, speakers named a target object that was presented with a context object. Using auditory distractors that were phonologically related or unrelated either to the target object or the context object, the authors assessed whether phonological processing was confined to the target object or not. Phonological…

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riddle, Reed L.; Bui, Khanh; Dekany, Richard G.

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 containmore » 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.« less

Object-based spatial attention when objects have sufficient depth cues.

PubMed

Takeya, Ryuji; Kasai, Tetsuko

2015-01-01

Attention directed to a part of an object tends to obligatorily spread over all of the spatial regions that belong to the object, which may be critical for rapid object-recognition in cluttered visual scenes. Previous studies have generally used simple rectangles as objects and have shown that attention spreading is reflected by amplitude modulation in the posterior N1 component (150-200 ms poststimulus) of event-related potentials, while other interpretations (i.e., rectangular holes) may arise implicitly in early visual processing stages. By using modified Kanizsa-type stimuli that provided less ambiguity of depth ordering, the present study examined early event-related potential spatial-attention effects for connected and separated objects, both of which were perceived in front of (Experiment 1) and in back of (Experiment 2) the surroundings. Typical P1 (100-140 ms) and N1 (150-220 ms) attention effects of ERP in response to unilateral probes were observed in both experiments. Importantly, the P1 attention effect was decreased for connected objects compared to separated objects only in Experiment 1, and the typical object-based modulations of N1 were not observed in either experiment. These results suggest that spatial attention spreads over a figural object at earlier stages of processing than previously indicated, in three-dimensional visual scenes with multiple depth cues.

Removal of surfactants nonylphenol ethoxylates from municipal sewage-comparison of an A/O process and biological aerated filters.

PubMed

Gao, Dawen; Li, Zhe; Guan, Junxue; Li, Yifan; Ren, Nanqi

2014-02-01

The concentrations of nonylphenol ethoxylates (NPnEO, n=1 to 2) and nonylphenol (NP) in water and sludge samples were measured from a full scale sewage treatment plant (STP) with an Anaerobic/Oxic (A/O) and a Biological Aerated Filter (BAF) process. The A/O process was found to exhibit improved performance in comparison to the BAF process. Mean values of NP, NP1EO and NP2EO concentrations in influents from the STP were similar, ranging from 1.8 to 2.0×10(3)ngL(-1). In the A/O process, the removal efficiency of NP, NP1EO and NP2EO from the aqueous phase was 78%, 84%, and 89%, respectively. In contrast, the removal efficiencies of NP, NP1EO, and NP2EO were relatively lower for the BAF process, at 55%, 76%, and 79%, respectively. High concentrations of NP, NP1EO and NP2EO detected in the sludge samples had a maximum value of 2.7μgg(-1) dw, which indicates that improvement in the overall elimination of NP, NP1EO and NP2EO may be associated with adsorption by the sludge. To further investigate the fate of NP, NP1EO and NP2EO in the STP, our research assessed the degradation characteristics of NP by calculating its transformational loss in the STP. The results demonstrate that the quantity of NP measured in the effluent from the oxic unit increased by 32%, which indicates that NP1EO and NP2EO may undergo degradation in the oxic conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Relationship between covalence and displacive phase transition temperature in RAO{sub 4} and LiAO{sub 3} (R = rare-earth element and A = Nb and Ta)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsunekawa, S.; Fukuda, T.; Kimiyama, T.

Crystal structure analyses by TOF neutron powder diffraction are performed for R TaO{sub 4} (R = rare-earth element) and the Ta-O interatomic distances are determined. The relationship between the covalency of A-O bonds (A = Nb and Ta), which show the most shortening upon phase transition, and the transition temperature is discussed for RAO{sub 4} and LiAO{sub 3}, and the parameters of Ta-O covalence are determined.

Multi-objective vs. single-objective calibration of a hydrologic model using single- and multi-objective screening

NASA Astrophysics Data System (ADS)

Mai, Juliane; Cuntz, Matthias; Shafii, Mahyar; Zink, Matthias; Schäfer, David; Thober, Stephan; Samaniego, Luis; Tolson, Bryan

2016-04-01

Hydrologic models are traditionally calibrated against observed streamflow. Recent studies have shown however, that only a few global model parameters are constrained using this kind of integral signal. They can be identified using prior screening techniques. Since different objectives might constrain different parameters, it is advisable to use multiple information to calibrate those models. One common approach is to combine these multiple objectives (MO) into one single objective (SO) function and allow the use of a SO optimization algorithm. Another strategy is to consider the different objectives separately and apply a MO Pareto optimization algorithm. In this study, two major research questions will be addressed: 1) How do multi-objective calibrations compare with corresponding single-objective calibrations? 2) How much do calibration results deteriorate when the number of calibrated parameters is reduced by a prior screening technique? The hydrologic model employed in this study is a distributed hydrologic model (mHM) with 52 model parameters, i.e. transfer coefficients. The model uses grid cells as a primary hydrologic unit, and accounts for processes like snow accumulation and melting, soil moisture dynamics, infiltration, surface runoff, evapotranspiration, subsurface storage and discharge generation. The model is applied in three distinct catchments over Europe. The SO calibrations are performed using the Dynamically Dimensioned Search (DDS) algorithm with a fixed budget while the MO calibrations are achieved using the Pareto Dynamically Dimensioned Search (PA-DDS) algorithm allowing for the same budget. The two objectives used here are the Nash Sutcliffe Efficiency (NSE) of the simulated streamflow and the NSE of the logarithmic transformation. It is shown that the SO DDS results are located close to the edges of the Pareto fronts of the PA-DDS. The MO calibrations are hence preferable due to their supply of multiple equivalent solutions from which the

Fuzzy connected object definition in images with respect to co-objects

NASA Astrophysics Data System (ADS)

Udupa, Jayaram K.; Saha, Punam K.; Lotufo, Roberto A.

1999-05-01

Tangible solutions to practical image segmentation are vital to ensure progress in many applications of medical imaging. Toward this goal, we previously proposed a theory and algorithms for fuzzy connected object definition in n- dimensional images. Their effectiveness has been demonstrated in several applications including multiple sclerosis lesion detection/delineation, MR Angiography, and craniofacial imaging. The purpose of this work is to extend the earlier theory and algorithms to fuzzy connected object definition that considers all relevant objects in the image simultaneously. In the previous theory, delineation of the final object from the fuzzy connectivity scene required the selection of a threshold that specifies the weakest `hanging-togetherness' of image elements relative to each other in the object. Selection of such a threshold was not trivial and has been an active research area. In the proposed method of relative fuzzy connectivity, instead of defining an object on its own based on the strength of connectedness, all co-objects of importance that are present in the image are also considered and the objects are let to compete among themselves in having image elements as their members. In this competition, every pair of elements in the image will have a strength of connectedness in each object. The object in which this strength is highest will claim membership of the elements. This approach to fuzzy object definition using a relative strength of connectedness eliminates the need for a threshold of strength of connectedness that was part of the previous definition. It seems to be more natural since it relies on the fact that an object gets defined in an image by the presence of other objects that coexist in the image. All specified objects are defined simultaneously in this approach. The concept of iterative relative fuzzy connectivity has also been introduced. Robustness of relative fuzzy objects with respect to selection of reference image elements

Variations of the Blazar AO 0235+164 in 2006-2015

NASA Astrophysics Data System (ADS)

Hagen-Thorn, V. A.; Larionov, V. M.; Morozova, D. A.; Arkharov, A. A.; Hagen-Thorn, E. I.; Shablovinskaya, E. S.; Prokop'eva, M. S.; Yakovleva, V. A.

2018-02-01

The results of optical, radio, and gamma-ray observations of the blazar AO 0235+16 are presented, including photometric ( BV RIJHK) and polarimetric ( R)monitoring carried out at St. Petersburg State University and the Central (Pulkovo) Astronomical Observatory in 2007-2015, 43 GHz Very Long Baseline Interferometry radio observations processed at Boston University, and a gamma-ray light curve based on observationswith the Fermi space observatory are presented. Two strong outbursts were detected. The relative spectral energy distributions of the variable components responsible for the outbursts are determined; these follow power laws, but with different spectral indices. The degree of polarization was high in both outbursts; only an average relationship between the brightness and polarization can be found. There was no time lag between the variations in the optical and gamma-ray, suggesting that the sources of the radiation in the optical and gamma-ray are located in the same region of the jet.

Seeing Objects as Faces Enhances Object Detection.

PubMed

Takahashi, Kohske; Watanabe, Katsumi

2015-10-01

The face is a special visual stimulus. Both bottom-up processes for low-level facial features and top-down modulation by face expectations contribute to the advantages of face perception. However, it is hard to dissociate the top-down factors from the bottom-up processes, since facial stimuli mandatorily lead to face awareness. In the present study, using the face pareidolia phenomenon, we demonstrated that face awareness, namely seeing an object as a face, enhances object detection performance. In face pareidolia, some people see a visual stimulus, for example, three dots arranged in V shape, as a face, while others do not. This phenomenon allows us to investigate the effect of face awareness leaving the stimulus per se unchanged. Participants were asked to detect a face target or a triangle target. While target per se was identical between the two tasks, the detection sensitivity was higher when the participants recognized the target as a face. This was the case irrespective of the stimulus eccentricity or the vertical orientation of the stimulus. These results demonstrate that seeing an object as a face facilitates object detection via top-down modulation. The advantages of face perception are, therefore, at least partly, due to face awareness.

Seeing Objects as Faces Enhances Object Detection

PubMed Central

Watanabe, Katsumi

2015-01-01

The face is a special visual stimulus. Both bottom-up processes for low-level facial features and top-down modulation by face expectations contribute to the advantages of face perception. However, it is hard to dissociate the top-down factors from the bottom-up processes, since facial stimuli mandatorily lead to face awareness. In the present study, using the face pareidolia phenomenon, we demonstrated that face awareness, namely seeing an object as a face, enhances object detection performance. In face pareidolia, some people see a visual stimulus, for example, three dots arranged in V shape, as a face, while others do not. This phenomenon allows us to investigate the effect of face awareness leaving the stimulus per se unchanged. Participants were asked to detect a face target or a triangle target. While target per se was identical between the two tasks, the detection sensitivity was higher when the participants recognized the target as a face. This was the case irrespective of the stimulus eccentricity or the vertical orientation of the stimulus. These results demonstrate that seeing an object as a face facilitates object detection via top-down modulation. The advantages of face perception are, therefore, at least partly, due to face awareness. PMID:27648219

Learned filters for object detection in multi-object visual tracking

NASA Astrophysics Data System (ADS)

Stamatescu, Victor; Wong, Sebastien; McDonnell, Mark D.; Kearney, David

2016-05-01

We investigate the application of learned convolutional filters in multi-object visual tracking. The filters were learned in both a supervised and unsupervised manner from image data using artificial neural networks. This work follows recent results in the field of machine learning that demonstrate the use learned filters for enhanced object detection and classification. Here we employ a track-before-detect approach to multi-object tracking, where tracking guides the detection process. The object detection provides a probabilistic input image calculated by selecting from features obtained using banks of generative or discriminative learned filters. We present a systematic evaluation of these convolutional filters using a real-world data set that examines their performance as generic object detectors.

Motivational Objects in Natural Scenes (MONS): A Database of >800 Objects.

PubMed

Schomaker, Judith; Rau, Elias M; Einhäuser, Wolfgang; Wittmann, Bianca C

2017-01-01

In daily life, we are surrounded by objects with pre-existing motivational associations. However, these are rarely controlled for in experiments with natural stimuli. Research on natural stimuli would therefore benefit from stimuli with well-defined motivational properties; in turn, such stimuli also open new paths in research on motivation. Here we introduce a database of Motivational Objects in Natural Scenes (MONS). The database consists of 107 scenes. Each scene contains 2 to 7 objects placed at approximately equal distance from the scene center. Each scene was photographed creating 3 versions, with one object ("critical object") being replaced to vary the overall motivational value of the scene (appetitive, aversive, and neutral), while maintaining high visual similarity between the three versions. Ratings on motivation, valence, arousal and recognizability were obtained using internet-based questionnaires. Since the main objective was to provide stimuli of well-defined motivational value, three motivation scales were used: (1) Desire to own the object; (2) Approach/Avoid; (3) Desire to interact with the object. Three sets of ratings were obtained in independent sets of observers: for all 805 objects presented on a neutral background, for 321 critical objects presented in their scene context, and for the entire scenes. On the basis of the motivational ratings, objects were subdivided into aversive, neutral, and appetitive categories. The MONS database will provide a standardized basis for future studies on motivational value under realistic conditions.

Exploring the relationship between object realism and object-based attention effects.

PubMed

Roque, Nelson; Boot, Walter R

2015-09-01

Visual attention prioritizes processing of locations in space, and evidence also suggests that the benefits of attention can be shaped by the presence of objects (object-based attention). However, the prevalence of object-based attention effects has been called into question recently by evidence from a large-sampled study employing classic attention paradigms (Pilz et al., 2012). We conducted two experiments to explore factors that might determine when and if object-based attention effects are observed, focusing on the degree to which the concreteness and realism of objects might contribute to these effects. We adapted the classic attention paradigm first reported by Egly, Driver, and Rafal (1994) by replacing abstract bar stimuli in some conditions with objects that were more concrete and familiar to participants: items of silverware. Furthermore, we varied the realism of these items of silverware, presenting either cartoon versions or photo-realistic versions. Contrary to predictions, increased realism did not increase the size of object-based effects. In fact, no clear object-based effects were observed in either experiment, consistent with previous failures to replicate these effects in similar paradigms. While object-based attention may exist, and may have important influences on how we parse the visual world, these and other findings suggest that the two-object paradigm typically relied upon to study object-based effects may not be the best paradigm to investigate these issues. Copyright © 2015 Elsevier B.V. All rights reserved.

Converting a carbon preform object to a silicon carbide object

NASA Technical Reports Server (NTRS)

Levin, Harry (Inventor)

1990-01-01

A process for converting in depth a carbon or graphite preform object to a silicon carbide object, silicon carbide/silicon object, silicon carbide/carbon-core object, or a silicon carbide/silicon/carbon-core object, by contacting it with silicon liquid and vapor over various lengths of contact time in a reaction chamber. In the process, a stream comprised of a silicon-containing precursor material in gaseous phase below the decomposition temperature of said gas and a coreactant, carrier or diluent gas such as hydrogen is passed through a hole within a high emissivity, thin, insulating septum into the reaction chamber above the melting point of silicon. The thin septum has one face below the decomposition temperature of the gas and an opposite face exposed to the reaction chamber. Thus, the precursor gas is decomposed directly to silicon in the reaction chamber. Any stream of decomposition gas and any unreacted precursor gas from the reaction chamber is removed. A carbon or graphite preform object placed in the reaction chamber is contacted with the silicon. The carbon or graphite preform object is recovered from the reactor chamber after it has been converted to a desired silicon carbide, silicon and carbon composition.

Trajectory Recognition as the Basis for Object Individuation: A Functional Model of Object File Instantiation and Object-Token Encoding

PubMed Central

Fields, Chris

2011-01-01

The perception of persisting visual objects is mediated by transient intermediate representations, object files, that are instantiated in response to some, but not all, visual trajectories. The standard object file concept does not, however, provide a mechanism sufficient to account for all experimental data on visual object persistence, object tracking, and the ability to perceive spatially disconnected stimuli as continuously existing objects. Based on relevant anatomical, functional, and developmental data, a functional model is constructed that bases visual object individuation on the recognition of temporal sequences of apparent center-of-mass positions that are specifically identified as trajectories by dedicated “trajectory recognition networks” downstream of the medial–temporal motion-detection area. This model is shown to account for a wide range of data, and to generate a variety of testable predictions. Individual differences in the recognition, abstraction, and encoding of trajectory information are expected to generate distinct object persistence judgments and object recognition abilities. Dominance of trajectory information over feature information in stored object tokens during early infancy, in particular, is expected to disrupt the ability to re-identify human and other individuals across perceptual episodes, and lead to developmental outcomes with characteristics of autism spectrum disorders. PMID:21716599

Feedback & Objectives

ERIC Educational Resources Information Center

Butterworth, James R.

1975-01-01

Industrial objectives, if they are employee oriented, produce feedback, and the motivation derived from the feedback helps reduce turnover. Feedback is the power to clarify objectives, to stimulate communication, and to motivate people. (Author/MW)

The Reviewing of Object Files: Object-Specific Integration of Information.

ERIC Educational Resources Information Center

Kahneman, Daniel; And Others

1992-01-01

Seven experiments involving a total of 203 college students explored a form of object-specific priming and established a robust object-specific benefit that indicates that a new stimulus will be named faster if it physically matches a previous stimulus seen as part of the same perceptual object. (SLD)

Unstable metacarpal and phalangeal fractures: treatment by internal fixation using AO mini-fragment plates and screws.

PubMed

Mumtaz, Mohammad Umar; Farooq, Muneer Ahmad; Rasool, Altaf Ahmad; Kawoosa, Altaf Ahmad; Badoo, Abdul Rashid; Dhar, Shabir Ahmad

2010-07-01

Accurate open reduction and internal fixation for metacarpal and phalangeal fractures of the hand is required in less than 5% of the patients; otherwise, closed treatment techniques offer satisfactory results in most of these cases as these fractures are stable either before or after closed reduction. AO mini-fragment screws and plates, when used in properly selected cases, can provide rigid fixation, allowing early mobilization of joints and hence good functional results while avoiding problems associated with protruding K-wires and immobilization. The advantages of such internal fixation urged us to undertake such a study in our state where such hand injuries are commonly seen. Forty patients with 42 unstable metacarpal and phalangeal fractures were treated with open reduction and internal fixation using AO mini-fragment screws and plates over a period of three years in a prospective manner. The overall results were good in 78.5% of cases, fair in 19% of cases and poor in 2.5% of cases, as judged according to the criteria of the American Society for Surgery of the Hand. This technique is a reasonable option for treating unstable metacarpal and phalangeal fractures as it provides a highly rigid fixation, which is sufficient to allow early mobilization of the adjacent joints, thus helping to achieve good functional results.

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

T'ao-t'ieh, a motif of Chinese funerary art as the iconographic counterpart of Cinnabar, an alchemical drug.

PubMed

Mahdihassan, S

1982-01-01

The agency conferring resurrection is soul or its emblem. The earliest conception of soul is blood. Its Redness penetrates subsoil and is taken up by serpent, from whence arises snake-soul, later snake-god. Blood vapours is the other fraction arising upwards. It becomes wraith bird, later soul bird, and finally bird god. Blood as whole gave snake-god plus bird-god. A winged-cobra became snake-god and bird-god or together, one-as-all. Red Cock was its equivalent. As substance came cinnabar, red like blood and sublimable like soul. Dragon was idealized snake-god. Then Dragon-god plus Bird-god became the equal of blood soul, the magical power. T'ao-t'ieh is Dragon-plus-Bird, snake-god plus bird-god, the equivalent of Cosmic soul. Then cinnabar as the equal of blood soul and T'ao-t'ieh, the emblem of Cosmic soul, each were capable of conferring resurrection and have been interred in Chinese graves.

Objects and categories: feature statistics and object processing in the ventral stream.

PubMed

Tyler, Lorraine K; Chiu, Shannon; Zhuang, Jie; Randall, Billi; Devereux, Barry J; Wright, Paul; Clarke, Alex; Taylor, Kirsten I

2013-10-01

Recognizing an object involves more than just visual analyses; its meaning must also be decoded. Extensive research has shown that processing the visual properties of objects relies on a hierarchically organized stream in ventral occipitotemporal cortex, with increasingly more complex visual features being coded from posterior to anterior sites culminating in the perirhinal cortex (PRC) in the anteromedial temporal lobe (aMTL). The neurobiological principles of the conceptual analysis of objects remain more controversial. Much research has focused on two neural regions-the fusiform gyrus and aMTL, both of which show semantic category differences, but of different types. fMRI studies show category differentiation in the fusiform gyrus, based on clusters of semantically similar objects, whereas category-specific deficits, specifically for living things, are associated with damage to the aMTL. These category-specific deficits for living things have been attributed to problems in differentiating between highly similar objects, a process that involves the PRC. To determine whether the PRC and the fusiform gyri contribute to different aspects of an object's meaning, with differentiation between confusable objects in the PRC and categorization based on object similarity in the fusiform, we carried out an fMRI study of object processing based on a feature-based model that characterizes the degree of semantic similarity and difference between objects and object categories. Participants saw 388 objects for which feature statistic information was available and named the objects at the basic level while undergoing fMRI scanning. After controlling for the effects of visual information, we found that feature statistics that capture similarity between objects formed category clusters in fusiform gyri, such that objects with many shared features (typical of living things) were associated with activity in the lateral fusiform gyri whereas objects with fewer shared features (typical

Pegasus

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

(the Winged Horse; abbrev. Peg, gen. Pegasi; area 1121 sq. deg.) A northern constellation that extends from Cygnus, Lacerta and Andromeda almost to the celestial equator, and culminates at midnight in early September. It is named after the winged horse in Greek mythology that sprang from the body of Medusa, the Gorgon, when she was beheaded by Perseus, and later was tamed by the hero Bellerophon. ...

Motivational Objects in Natural Scenes (MONS): A Database of >800 Objects

PubMed Central

Schomaker, Judith; Rau, Elias M.; Einhäuser, Wolfgang; Wittmann, Bianca C.

2017-01-01

In daily life, we are surrounded by objects with pre-existing motivational associations. However, these are rarely controlled for in experiments with natural stimuli. Research on natural stimuli would therefore benefit from stimuli with well-defined motivational properties; in turn, such stimuli also open new paths in research on motivation. Here we introduce a database of Motivational Objects in Natural Scenes (MONS). The database consists of 107 scenes. Each scene contains 2 to 7 objects placed at approximately equal distance from the scene center. Each scene was photographed creating 3 versions, with one object (“critical object”) being replaced to vary the overall motivational value of the scene (appetitive, aversive, and neutral), while maintaining high visual similarity between the three versions. Ratings on motivation, valence, arousal and recognizability were obtained using internet-based questionnaires. Since the main objective was to provide stimuli of well-defined motivational value, three motivation scales were used: (1) Desire to own the object; (2) Approach/Avoid; (3) Desire to interact with the object. Three sets of ratings were obtained in independent sets of observers: for all 805 objects presented on a neutral background, for 321 critical objects presented in their scene context, and for the entire scenes. On the basis of the motivational ratings, objects were subdivided into aversive, neutral, and appetitive categories. The MONS database will provide a standardized basis for future studies on motivational value under realistic conditions. PMID:29033870

Academy of Reading® (AoR) 2008-09 and 2009-10 Evaluation. E&R Report No. 10.23

ERIC Educational Resources Information Center

Baenen, Nancy; Lougee, Aimee

2011-01-01

Academy of READING (AoR) is designed to improve students' foundational reading skills; it is used in almost all Wake County Public Schools (WCPSS) secondary schools. Central staff recommended students with prior End of Grade/Course (EOG/EOC) scale scores placing them high in Level II or low in Level III have first priority for service; many…

Clinical therapeutic effects of AO/ASIF clavicle hook plate on distal clavicle fractures and acromioclavicular joint dislocations.

PubMed

Dou, Qingjun; Ren, Xiaofeng

2014-07-01

The aim of this study was to evaluate the security and effectiveness of AO/ASIF clavicle hook plate in the treatment of distal clavicle fractures and acromioclavicular joint dislocations. One hundred patients with distal clavicle fractures and acromioclavicular joint dislocations who were admitted in our hospital from January 2012 to January 2013 were selected as the study subjects. They were then randomly divided into a control group and an observation group (n=50). The observation group was treated with AO/ASIF clavicle hook plates, and the control group was treated with Kirschner-wire tension bands. The outcomes were recorded and compared. The JOA scores of the two groups were similar before surgery (P>0.05). The two groups both had obviously increased JOA scores in the postoperative 6th and 12th weeks, and the score in the postoperative 12th week was higher. There were statistically significant intra-group differences (P<0.05). The postoperative 6th-week and 12th-week JOA scores of the observation group were (83.2±1.8) and (97.4±1.5) respectively, and those of the control group were (71.6±2.2) and (82.3±2.6) respectively, with statistically significant inter-group differences (P<0.05). Significantly more patients in the observation group (100%) were evaluated as excellent or good outcomes after fixation than those in the control group (60%). After removal of the surgical apparatus, the recurrence rates of bone fracture and joint dislocation in the observation group were significantly lower than those of the control group (P<0.05). AO/ASIF clavicle hook plate functioned more effectively than Kirschner-wire tension band in clinical treatment of distal clavicle fractures and acromioclavicular joint dislocations. The former protocol enjoyed small incisions, firm fixation and early shoulder mobility. Therefore, it is a safe and effective surgical method that is worthy of being widely applied in clinical practice.

Bias effects in the possible/impossible object decision test with matching objects.

PubMed

Soldan, Anja; Hilton, H John; Stern, Yaakov

2009-03-01

In the possible/impossible object decision test, priming has consistently been found for structurally possible, but not impossible, objects, leading Schacter, Cooper, and Delaney (1990) to suggest that priming relies on a system that represents the global 3-D structure of objects. Using a modified design with matching objects to control for the influence of episodic memory, Ratcliff and McKoon (1995) and Williams and Tarr (1997) found negative priming for impossible objects (i.e., lower performance for old than for new items). Both teams argued that priming derives from (1) episodic memory for object features and (2) bias to respond "possible" to encoded objects or their possible parts. The present study applied the matched-objects design to the original Schacter and Cooper stimuli-same possible objects and matching impossible figures-with minimal procedural variation. The data from Experiment 1 only partially supported the bias models and suggested that priming was mediated by both local and global structural descriptions. Experiment 2 showed that negative priming for impossible objects derived from the structural properties of these objects, not from the influence of episodic memory on task performance. Supplemental materials for this study may be downloaded from mc.psychonomic-journals.org/content/supplemental.

Fourier analysis of blazar variability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finke, Justin D.; Becker, Peter A., E-mail: justin.finke@nrl.navy.mil

Blazars display strong variability on multiple timescales and in multiple radiation bands. Their variability is often characterized by power spectral densities (PSDs) and time lags plotted as functions of the Fourier frequency. We develop a new theoretical model based on the analysis of the electron transport (continuity) equation, carried out in the Fourier domain. The continuity equation includes electron cooling and escape, and a derivation of the emission properties includes light travel time effects associated with a radiating blob in a relativistic jet. The model successfully reproduces the general shapes of the observed PSDs and predicts specific PSD and timemore » lag behaviors associated with variability in the synchrotron, synchrotron self-Compton, and external Compton emission components, from submillimeter to γ-rays. We discuss applications to BL Lacertae objects and to flat-spectrum radio quasars (FSRQs), where there are hints that some of the predicted features have already been observed. We also find that FSRQs should have steeper γ-ray PSD power-law indices than BL Lac objects at Fourier frequencies ≲ 10{sup –4} Hz, in qualitative agreement with previously reported observations by the Fermi Large Area Telescope.« less

Interactive object recognition assistance: an approach to recognition starting from target objects

NASA Astrophysics Data System (ADS)

Geisler, Juergen; Littfass, Michael

1999-07-01

Recognition of target objects in remotely sensed imagery required detailed knowledge about the target object domain as well as about mapping properties of the sensing system. The art of object recognition is to combine both worlds appropriately and to provide models of target appearance with respect to sensor characteristics. Common approaches to support interactive object recognition are either driven from the sensor point of view and address the problem of displaying images in a manner adequate to the sensing system. Or they focus on target objects and provide exhaustive encyclopedic information about this domain. Our paper discusses an approach to assist interactive object recognition based on knowledge about target objects and taking into account the significance of object features with respect to characteristics of the sensed imagery, e.g. spatial and spectral resolution. An `interactive recognition assistant' takes the image analyst through the interpretation process by indicating step-by-step the respectively most significant features of objects in an actual set of candidates. The significance of object features is expressed by pregenerated trees of significance, and by the dynamic computation of decision relevance for every feature at each step of the recognition process. In the context of this approach we discuss the question of modeling and storing the multisensorial/multispectral appearances of target objects and object classes as well as the problem of an adequate dynamic human-machine-interface that takes into account various mental models of human image interpretation.

Object Locating System

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey (Inventor); Carl, James R. (Inventor)

2000-01-01

A portable system is provided that is operational for determining, with three dimensional resolution, the position of a buried object or approximately positioned object that may move in space or air or gas. The system has a plurality of receivers for detecting the signal front a target antenna and measuring the phase thereof with respect to a reference signal. The relative permittivity and conductivity of the medium in which the object is located is used along with the measured phase signal to determine a distance between the object and each of the plurality of receivers. Knowing these distances. an iteration technique is provided for solving equations simultaneously to provide position coordinates. The system may also be used for tracking movement of an object within close range of the system by sampling and recording subsequent position of the object. A dipole target antenna. when positioned adjacent to a buried object, may be energized using a separate transmitter which couples energy to the target antenna through the medium. The target antenna then preferably resonates at a different frequency, such as a second harmonic of the transmitter frequency.

Photometric Redshifts of High-z BL Lacs from 3FGL Catalog

NASA Astrophysics Data System (ADS)

Kaur, A.; Rau, Arne; Ajello, Marco; Paliya, Vaidehi; Hartmann, Dieter; Greiner, Jochen; Bolmer, Jan; Schady, Patricia

2017-08-01

Determining redshifts for BL Lacertae (BL Lac) objects using the traditional spectroscopic method is challenging due to the absence of strong emission lines in their optical spectra. We employ the photometric dropout technique to determine redshifts for this class of blazars using the combined 13 broad-band filters from Swift-UVOT and the multi-channel imager GROND at the MPG 2.2 m telescope at ESO's La Silla Observatory. The wavelength range covered by these 13 filters extends from far ultraviolet to the near-Infrared. We report results on 40 new Fermi detected BL Lacs with the photometric redshifts determinations for 5 sources, with 3FGL J1918.2-4110 being the most distance in our sample at z=2.16. Reliable upper limits are provided for 20 sources in this sample. Using the highest energy photons for these Fermi-LAT sources, we evaluate the consistency with the Gamma-ray horizon due to the extragalactic background light.

Flat spectrum multicomponent radio sources - Cosmic conspiracy or geometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pacholczyk, A.G.

1981-01-01

Compact radio sources which do not exhibit currently large flux density variations, are often characterized by spectra nearly flat over a wide range of wavelengths. Cotton et al. (1980) recently reported the results of the VLBI multifrequency interferometric and total flux density observations of a typical representative of the flat spectrum class of sources, a BL Lacertae object PKS 0735+178. If 0735+178 is indeed representative of flat spectrum sources, then some mechanism causing the component production and energy loss to be balanced must be operative among this type of radio source to maintain a flat spectrum over at least certainmore » periods of time. This effect is referred to as 'cosmic conspiracy'. It is suggested that the flatness of spectra of this class of radio sources may be related to a specific symmetry in the radio structure, namely, to a predominantly linear, one-dimensional evolution of radio radiating material, rather than spherical, three-dimensional evolution.« less

Parietal and frontal object areas underlie perception of object orientation in depth.

PubMed

Niimi, Ryosuke; Saneyoshi, Ayako; Abe, Reiko; Kaminaga, Tatsuro; Yokosawa, Kazuhiko

2011-05-27

Recent studies have shown that the human parietal and frontal cortices are involved in object image perception. We hypothesized that the parietal/frontal object areas play a role in differentiating the orientations (i.e., views) of an object. By using functional magnetic resonance imaging, we compared brain activations while human observers differentiated between two object images in depth-orientation (orientation task) and activations while they differentiated the images in object identity (identity task). The left intraparietal area, right angular gyrus, and right inferior frontal areas were activated more for the orientation task than for the identity task. The occipitotemporal object areas, however, were activated equally for the two tasks. No region showed greater activation for the identity task. These results suggested that the parietal/frontal object areas encode view-dependent visual features and underlie object orientation perception. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

The CHARIS Integral Field Spectrograph with SCExAO: Data Reduction and Performance

NASA Astrophysics Data System (ADS)

Kasdin, N. Jeremy; Groff, Tyler; Brandt, Timothy; Currie, Thayne; Rizzo, Maxime; Chilcote, Jeffrey K.; Guyon, Olivier; Jovanovic, Nemanja; Lozi, Julien; Norris, Barnaby; Tamura, Motohide

2018-01-01

We summarize the data reduction pipeline and on-sky performance of the CHARIS Integral Field Spectrograph behind the SCExAO Adaptive Optics system on the Subaru Telescope. The open-source pipeline produces data cubes from raw detector reads using a Χ^2-based spectral extraction technique. It implements a number of advances, including a fit to the full nonlinear pixel response, suppression of up to a factor of ~2 in read noise, and deconvolution of the spectra with the line-spread function. The CHARIS team is currently developing the calibration and postprocessing software that will comprise the second component of the data reduction pipeline. Here, we show a range of CHARIS images, spectra, and contrast curves produced using provisional routines. CHARIS is now characterizing exoplanets simultaneously across the J, H, and K bands.

Desired Precision in Multi-Objective Optimization: Epsilon Archiving or Rounding Objectives?

NASA Astrophysics Data System (ADS)

Asadzadeh, M.; Sahraei, S.

2016-12-01

Multi-objective optimization (MO) aids in supporting the decision making process in water resources engineering and design problems. One of the main goals of solving a MO problem is to archive a set of solutions that is well-distributed across a wide range of all the design objectives. Modern MO algorithms use the epsilon dominance concept to define a mesh with pre-defined grid-cell size (often called epsilon) in the objective space and archive at most one solution at each grid-cell. Epsilon can be set to the desired precision level of each objective function to make sure that the difference between each pair of archived solutions is meaningful. This epsilon archiving process is computationally expensive in problems that have quick-to-evaluate objective functions. This research explores the applicability of a similar but computationally more efficient approach to respect the desired precision level of all objectives in the solution archiving process. In this alternative approach each objective function is rounded to the desired precision level before comparing any new solution to the set of archived solutions that already have rounded objective function values. This alternative solution archiving approach is compared to the epsilon archiving approach in terms of efficiency and quality of archived solutions for solving mathematical test problems and hydrologic model calibration problems.

Agile Objects

ERIC Educational Resources Information Center

German, Senta; Harris, Jim

2017-01-01

In this article, the authors argue that the art-historical canon, however it is construed, has little relevance to the selection of objects for museum-based teaching. Their contention is that all objects are fundamentally agile and capable of interrogation from any number of disciplinary standpoints, and that the canon of museum education,…

Early object relations into new objects.

PubMed

Downey, T W

2001-01-01

Two strands of change are suggested by this review, one maturational, the other therapeutic or developmental (Hartmann and Kris, 1945). By "maturational" I mean to suggest energies that infuse the individual from earliest life in a manner that includes object relations, but for the healthy exercise of which object relations per se need not be of central and crucial importance. Within wide limits such energies may be delayed until growth conditions prevail without significant distortion of certain of the organism's ego functions. Therapeutic change is analogous to developmental change in that both involve the crucial presence of another to release energies. In therapeutic change these are energies that have been repressed beyond the reach of developmental dynamics. In everyday development crisis and synthesis alternate in conjunction with new and emerging objects to add to the psychological structures brought to the fore by maturation. In many instances, as we see with John, over time and in a less focussed manner, developmental changes can approximate therapeutic change and visa versa. Freud-Dann in their "experiment" pursued one line, in which the equipmental delay brought on by extremely adverse living circumstances was redressed by providing an interpersonally enriching, loving, developmentally facilitating milieu. The sketches of individual children and John's subsequent story provide a perspective into what becomes the stuff of growth and what remains the stuff of neurosis. The developmental reserves and ego resilience of these children were impressive but probably not extraordinary. Usual growth ensued as soon as they were provided with the rich soil of Bulldogs Bank instead of the desert sand of the Tereszin concentration camp. However, no one can escape such adverse circumstances without having taken in the stuff of neurosis. Affects and percepts that were not assimilatable or even available to consciousness at the time remain buried in the unconscious

The progress of Chinese burn medicine from the Third Military Medical University-in memory of its pioneer, Professor Li Ao.

PubMed

Li, Haisheng; Zhou, Junyi; Peng, Yizhi; Zhang, Jiaping; Peng, Xi; Luo, Qizhi; Yuan, Zhiqiang; Yan, Hong; Peng, Daizhi; He, Weifeng; Wang, Fengjun; Liang, Guangping; Huang, Yuesheng; Wu, Jun; Luo, Gaoxing

2017-01-01

Professor Li Ao was one of the founders of Chinese burn medicine and one of the most renowned doctors and researchers of burns in China. He established one of the Chinese earliest special departments for burns at Third Military Medical University (TMMU) in 1958. To memorialize Professor Li Ao on his 100th birthday in 2017 and introduce our extensive experience, it is our honor to briefly review the development and achievement of the Chinese burn medicine from TMMU. The epidemiology and outcomes of admitted burn patients since 1958 were reviewed. Furthermore, main achievements of basic and clinical research for the past roughly 60 years were presented. These achievements mainly included the Chinese Rule of Nine, fluid resuscitation protocol, experience in inhalation injury, wound treatment strategies, prevention and treatment of burn infections, nutrition therapy, organ support therapies, and rehabilitation. The progress shaped and enriched modern Chinese burn medicine and promoted the development of world burn medicine.

Between-object and within-object saccade programming in a visual search task.

PubMed

Vergilino-Perez, Dorine; Findlay, John M

2006-07-01

The role of the perceptual organization of the visual display on eye movement control was examined in two experiments using a task where a two-saccade sequence was directed toward either a single elongated object or three separate shorter objects. In the first experiment, we examined the consequences for the second saccade of a small displacement of the whole display during the first saccade. We found that between-object saccades compensated for the displacement to aim for a target position on the new object whereas within-object saccades did not show compensation but were coded as a fixed motor vector applied irrespective of wherever the preceding saccade landed. In the second experiment, we extended the paradigm to examine saccades performed in different directions. The results suggest that the within-object and between-object saccade distinction is an essential feature of saccadic planning.

Telescópio de pequeno porte como suporte ao ensino em cidades com intensa poluição luminosa II

NASA Astrophysics Data System (ADS)

Pereira, P. C. R.; Santos-Júnior, J. M.; Cruz, W. S.

2003-08-01

Para a maioria dos estudantes, sua passagem pelo ensino formal fundamental envolve a transmissão de fatos que devem ser guardados para um exame, a habilidade para lembrar fórmulas e, eventualmente, a repetição de experimentos que devem produzir resultados exigidos pelo professor. O resultado deste modelo de ensino, ao longo dos anos, é conhecido por todos: desconhecimento e descontentamento, por parte dos estudantes, de temas relativos ao papel e aos processos da ciência. Acreditamos que a Astronomia, pelo seu caráter observacional, é uma das áreas do conhecimento que pode contribuir neste cenário. A Fundação Planetário da Cidade do Rio de Janeiro possui um telescópio Meade LX-200 (25cm) que, juntamente com as câmeras CCD ST-7E e ST8E, tem sido utilizado em projetos voltados aos estudantes do ensino médio desde o ano 2000. Tais projetos envolvem a condução de um projeto de pesquisa observacional num nível apropriado, e possibilitam o contato com técnicas e novas tecnologias: computador, software para manipulação de dados e gráficos, programas de tratamento e redução de dados, uso de equipamentos óptico-eletrônicos (telescópio e CCD), bem como o processo de aquisição de conhecimento. Dentro da proposta dos anos anteriores, priorizamos projetos de uma noite, ou seja, procuramos trabalhar com fenômenos que apresentem variabilidade com intervalo de recorrência relativamente curto. Em todos os casos, optamos pela fotometria diferencial, que tem se mostrado bastante eficiente para o céu luminoso como o da cidade do Rio de Janeiro. Neste painel, apresentamos alguns dos projetos desenvolvidos no último ano, com 25 estudantes. Apresentamos os resultados da observação da variável pulsante AI Vel (V = 6,6) e da variável cataclísmica FO Aqr (V = 13,5), e do monitoramento do trânsito da lua de Júpiter, Europa, ocorrido em 30 de abril de 2003. As curvas de luz produzidas para as primeiras estão concordantes com as da literatura, assim

Objective lens

NASA Technical Reports Server (NTRS)

Olczak, Eugene G. (Inventor)

2011-01-01

An objective lens and a method for using same. The objective lens has a first end, a second end, and a plurality of optical elements. The optical elements are positioned between the first end and the second end and are at least substantially symmetric about a plane centered between the first end and the second end.

A high-throughput AO/PI-based cell concentration and viability detection method using the Celigo image cytometry.

PubMed

Chan, Leo Li-Ying; Smith, Tim; Kumph, Kendra A; Kuksin, Dmitry; Kessel, Sarah; Déry, Olivier; Cribbes, Scott; Lai, Ning; Qiu, Jean

2016-10-01

To ensure cell-based assays are performed properly, both cell concentration and viability have to be determined so that the data can be normalized to generate meaningful and comparable results. Cell-based assays performed in immuno-oncology, toxicology, or bioprocessing research often require measuring of multiple samples and conditions, thus the current automated cell counter that uses single disposable counting slides is not practical for high-throughput screening assays. In the recent years, a plate-based image cytometry system has been developed for high-throughput biomolecular screening assays. In this work, we demonstrate a high-throughput AO/PI-based cell concentration and viability method using the Celigo image cytometer. First, we validate the method by comparing directly to Cellometer automated cell counter. Next, cell concentration dynamic range, viability dynamic range, and consistency are determined. The high-throughput AO/PI method described here allows for 96-well to 384-well plate samples to be analyzed in less than 7 min, which greatly reduces the time required for the single sample-based automated cell counter. In addition, this method can improve the efficiency for high-throughput screening assays, where multiple cell counts and viability measurements are needed prior to performing assays such as flow cytometry, ELISA, or simply plating cells for cell culture.

Picturing Objects in Infancy

ERIC Educational Resources Information Center

Shinskey, Jeanne L.; Jachens, Liza J.

2014-01-01

Infants' transfer of information from pictures to objects was tested by familiarizing 9-month-olds (N = 31) with either a color or black-and-white photograph of an object and observing their preferential reaching for the real target object versus a distractor. One condition tested object recognition by keeping both objects visible, and the…

Newborn chickens generate invariant object representations at the onset of visual object experience

PubMed Central

Wood, Justin N.

2013-01-01

To recognize objects quickly and accurately, mature visual systems build invariant object representations that generalize across a range of novel viewing conditions (e.g., changes in viewpoint). To date, however, the origins of this core cognitive ability have not yet been established. To examine how invariant object recognition develops in a newborn visual system, I raised chickens from birth for 2 weeks within controlled-rearing chambers. These chambers provided complete control over all visual object experiences. In the first week of life, subjects’ visual object experience was limited to a single virtual object rotating through a 60° viewpoint range. In the second week of life, I examined whether subjects could recognize that virtual object from novel viewpoints. Newborn chickens were able to generate viewpoint-invariant representations that supported object recognition across large, novel, and complex changes in the object’s appearance. Thus, newborn visual systems can begin building invariant object representations at the onset of visual object experience. These abstract representations can be generated from sparse data, in this case from a visual world containing a single virtual object seen from a limited range of viewpoints. This study shows that powerful, robust, and invariant object recognition machinery is an inherent feature of the newborn brain. PMID:23918372

Natural guide-star processing for wide-field laser-assisted AO systems

NASA Astrophysics Data System (ADS)

Correia, Carlos M.; Neichel, Benoit; Conan, Jean-Marc; Petit, Cyril; Sauvage, Jean-Francois; Fusco, Thierry; Vernet, Joel D. R.; Thatte, Niranjan

2016-07-01

Sky-coverage in laser-assisted AO observations largely depends on the system's capability to guide on the faintest natural guide-stars possible. Here we give an up-to-date status of our natural guide-star processing tailored to the European-ELT's visible and near-infrared (0.47 to 2.45 μm) integral field spectrograph - Harmoni. We tour the processing of both the isoplanatic and anisoplanatic tilt modes using the spatio-angular approach whereby the wavefront is estimated directly in the pupil plane avoiding a cumbersome explicit layered estimation on the 35-layer profiles we're currently using. Taking the case of Harmoni, we cover the choice of wave-front sensors, the number and field location of guide-stars, the optimised algorithms to beat down angular anisoplanatism and the performance obtained with different temporal controllers under split high-order/low-order tomography or joint tomography. We consider both atmospheric and far greater telescope wind buffeting disturbances. In addition we provide the sky-coverage estimates thus obtained.

A unified computational model of the development of object unity, object permanence, and occluded object trajectory perception.

PubMed

Franz, A; Triesch, J

2010-12-01

The perception of the unity of objects, their permanence when out of sight, and the ability to perceive continuous object trajectories even during occlusion belong to the first and most important capacities that infants have to acquire. Despite much research a unified model of the development of these abilities is still missing. Here we make an attempt to provide such a unified model. We present a recurrent artificial neural network that learns to predict the motion of stimuli occluding each other and that develops representations of occluded object parts. It represents completely occluded, moving objects for several time steps and successfully predicts their reappearance after occlusion. This framework allows us to account for a broad range of experimental data. Specifically, the model explains how the perception of object unity develops, the role of the width of the occluders, and it also accounts for differences between data for moving and stationary stimuli. We demonstrate that these abilities can be acquired by learning to predict the sensory input. The model makes specific predictions and provides a unifying framework that has the potential to be extended to other visual event categories. Copyright © 2010 Elsevier Inc. All rights reserved.

Objects in Motion

ERIC Educational Resources Information Center

Damonte, Kathleen

2004-01-01

One thing scientists study is how objects move. A famous scientist named Sir Isaac Newton (1642-1727) spent a lot of time observing objects in motion and came up with three laws that describe how things move. This explanation only deals with the first of his three laws of motion. Newton's First Law of Motion says that moving objects will continue…

A comparison of moving object detection methods for real-time moving object detection

NASA Astrophysics Data System (ADS)

Roshan, Aditya; Zhang, Yun

2014-06-01

Moving object detection has a wide variety of applications from traffic monitoring, site monitoring, automatic theft identification, face detection to military surveillance. Many methods have been developed across the globe for moving object detection, but it is very difficult to find one which can work globally in all situations and with different types of videos. The purpose of this paper is to evaluate existing moving object detection methods which can be implemented in software on a desktop or laptop, for real time object detection. There are several moving object detection methods noted in the literature, but few of them are suitable for real time moving object detection. Most of the methods which provide for real time movement are further limited by the number of objects and the scene complexity. This paper evaluates the four most commonly used moving object detection methods as background subtraction technique, Gaussian mixture model, wavelet based and optical flow based methods. The work is based on evaluation of these four moving object detection methods using two (2) different sets of cameras and two (2) different scenes. The moving object detection methods have been implemented using MatLab and results are compared based on completeness of detected objects, noise, light change sensitivity, processing time etc. After comparison, it is observed that optical flow based method took least processing time and successfully detected boundary of moving objects which also implies that it can be implemented for real-time moving object detection.

Spatially rearranged object parts can facilitate perception of intact whole objects.

PubMed

Cacciamani, Laura; Ayars, Alisabeth A; Peterson, Mary A

2014-01-01

The familiarity of an object depends on the spatial arrangement of its parts; when the parts are spatially rearranged, they form a novel, unrecognizable configuration. Yet the same collection of parts comprises both the familiar and novel configuration. Is it possible that the collection of familiar parts activates a representation of the intact familiar configuration even when they are spatially rearranged? We presented novel configurations as primes before test displays that assayed effects on figure-ground perception from memories of intact familiar objects. In our test displays, two equal-area regions shared a central border; one region depicted a portion of a familiar object. Previous research with such displays has shown that participants are more likely to perceive the region depicting a familiar object as the figure and the abutting region as its ground when the familiar object is depicted in its upright orientation rather than upside down. The novel primes comprised either the same or a different collection of parts as the familiar object in the test display (part-rearranged and control primes, respectively). We found that participants were more likely to perceive the familiar region as figure in upright vs. inverted displays following part-rearranged primes but not control primes. Thus, priming with a novel configuration comprising the same familiar parts as the upcoming figure-ground display facilitated orientation-dependent effects of object memories on figure assignment. Similar results were obtained when the spatially rearranged collection of parts was suggested on the groundside of the prime's border, suggesting that familiar parts in novel configurations access the representation of their corresponding intact whole object before figure assignment. These data demonstrate that familiar parts access memories of familiar objects even when they are arranged in a novel configuration.

Spatially rearranged object parts can facilitate perception of intact whole objects

PubMed Central

Cacciamani, Laura; Ayars, Alisabeth A.; Peterson, Mary A.

2014-01-01

The familiarity of an object depends on the spatial arrangement of its parts; when the parts are spatially rearranged, they form a novel, unrecognizable configuration. Yet the same collection of parts comprises both the familiar and novel configuration. Is it possible that the collection of familiar parts activates a representation of the intact familiar configuration even when they are spatially rearranged? We presented novel configurations as primes before test displays that assayed effects on figure-ground perception from memories of intact familiar objects. In our test displays, two equal-area regions shared a central border; one region depicted a portion of a familiar object. Previous research with such displays has shown that participants are more likely to perceive the region depicting a familiar object as the figure and the abutting region as its ground when the familiar object is depicted in its upright orientation rather than upside down. The novel primes comprised either the same or a different collection of parts as the familiar object in the test display (part-rearranged and control primes, respectively). We found that participants were more likely to perceive the familiar region as figure in upright vs. inverted displays following part-rearranged primes but not control primes. Thus, priming with a novel configuration comprising the same familiar parts as the upcoming figure-ground display facilitated orientation-dependent effects of object memories on figure assignment. Similar results were obtained when the spatially rearranged collection of parts was suggested on the groundside of the prime's border, suggesting that familiar parts in novel configurations access the representation of their corresponding intact whole object before figure assignment. These data demonstrate that familiar parts access memories of familiar objects even when they are arranged in a novel configuration. PMID:24904495

General object recognition is specific: Evidence from novel and familiar objects.

PubMed

Richler, Jennifer J; Wilmer, Jeremy B; Gauthier, Isabel

2017-09-01

In tests of object recognition, individual differences typically correlate modestly but nontrivially across familiar categories (e.g. cars, faces, shoes, birds, mushrooms). In theory, these correlations could reflect either global, non-specific mechanisms, such as general intelligence (IQ), or more specific mechanisms. Here, we introduce two separate methods for effectively capturing category-general performance variation, one that uses novel objects and one that uses familiar objects. In each case, we show that category-general performance variance is unrelated to IQ, thereby implicating more specific mechanisms. The first approach examines three newly developed novel object memory tests (NOMTs). We predicted that NOMTs would exhibit more shared, category-general variance than familiar object memory tests (FOMTs) because novel objects, unlike familiar objects, lack category-specific environmental influences (e.g. exposure to car magazines or botany classes). This prediction held, and remarkably, virtually none of the substantial shared variance among NOMTs was explained by IQ. Also, while NOMTs correlated nontrivially with two FOMTs (faces, cars), these correlations were smaller than among NOMTs and no larger than between the face and car tests themselves, suggesting that the category-general variance captured by NOMTs is specific not only relative to IQ, but also, to some degree, relative to both face and car recognition. The second approach averaged performance across multiple FOMTs, which we predicted would increase category-general variance by averaging out category-specific factors. This prediction held, and as with NOMTs, virtually none of the shared variance among FOMTs was explained by IQ. Overall, these results support the existence of object recognition mechanisms that, though category-general, are specific relative to IQ and substantially separable from face and car recognition. They also add sensitive, well-normed NOMTs to the tools available to study

Binding Objects to Locations: The Relationship between Object Files and Visual Working Memory

ERIC Educational Resources Information Center

Hollingworth, Andrew; Rasmussen, Ian P.

2010-01-01

The relationship between object files and visual working memory (VWM) was investigated in a new paradigm combining features of traditional VWM experiments (color change detection) and object-file experiments (memory for the properties of moving objects). Object-file theory was found to account for a key component of object-position binding in VWM:…

Functional expression of amine oxidase from Aspergillus niger (AO-I) in Saccharomyces cerevisiae.

PubMed

Kolaríková, Katerina; Galuszka, Petr; Sedlárová, Iva; Sebela, Marek; Frébort, Ivo

2009-01-01

The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle.

Calibration of the island effect: Experimental validation of closed-loop focal plane wavefront control on Subaru/SCExAO

NASA Astrophysics Data System (ADS)

N'Diaye, M.; Martinache, F.; Jovanovic, N.; Lozi, J.; Guyon, O.; Norris, B.; Ceau, A.; Mary, D.

2018-02-01

Context. Island effect (IE) aberrations are induced by differential pistons, tips, and tilts between neighboring pupil segments on ground-based telescopes, which severely limit the observations of circumstellar environments on the recently deployed exoplanet imagers (e.g., VLT/SPHERE, Gemini/GPI, Subaru/SCExAO) during the best observing conditions. Caused by air temperature gradients at the level of the telescope spiders, these aberrations were recently diagnosed with success on VLT/SPHERE, but so far no complete calibration has been performed to overcome this issue. Aims: We propose closed-loop focal plane wavefront control based on the asymmetric Fourier pupil wavefront sensor (APF-WFS) to calibrate these aberrations and improve the image quality of exoplanet high-contrast instruments in the presence of the IE. Methods: Assuming the archetypal four-quadrant aperture geometry in 8 m class telescopes, we describe these aberrations as a sum of the independent modes of piston, tip, and tilt that are distributed in each quadrant of the telescope pupil. We calibrate these modes with the APF-WFS before introducing our wavefront control for closed-loop operation. We perform numerical simulations and then experimental tests on a real system using Subaru/SCExAO to validate our control loop in the laboratory and on-sky. Results: Closed-loop operation with the APF-WFS enables the compensation for the IE in simulations and in the laboratory for the small aberration regime. Based on a calibration in the near infrared, we observe an improvement of the image quality in the visible range on the SCExAO/VAMPIRES module with a relative increase in the image Strehl ratio of 37%. Conclusions: Our first IE calibration paves the way for maximizing the science operations of the current exoplanet imagers. Such an approach and its results prove also very promising in light of the Extremely Large Telescopes (ELTs) and the presence of similar artifacts with their complex aperture geometry.

Strength of object representation: its key role in object-based attention for determining the competition result between Gestalt and top-down objects.

PubMed

Zhao, Jingjing; Wang, Yonghui; Liu, Donglai; Zhao, Liang; Liu, Peng

2015-10-01

It was found in previous studies that two types of objects (rectangles formed according to the Gestalt principle and Chinese words formed in a top-down fashion) can both induce an object-based effect. The aim of the present study was to investigate how the strength of an object representation affects the result of the competition between these two types of objects based on research carried out by Liu, Wang and Zhou [(2011) Acta Psychologica, 138(3), 397-404]. In Experiment 1, the rectangles were filled with two different colors to increase the strength of Gestalt object representation, and we found that the object effect changed significantly for the different stimulus types. Experiment 2 used Chinese words with various familiarities to manipulate the strength of the top-down object representation. As a result, the object-based effect induced by rectangles was observed only when the Chinese word familiarity was low. These results suggest that the strength of object representation determines the result of competition between different types of objects.

Multi objective multi refinery optimization with environmental and catastrophic failure effects objectives

NASA Astrophysics Data System (ADS)

Khogeer, Ahmed Sirag

2005-11-01

Petroleum refining is a capital-intensive business. With stringent environmental regulations on the processing industry and declining refining margins, political instability, increased risk of war and terrorist attacks in which refineries and fuel transportation grids may be targeted, higher pressures are exerted on refiners to optimize performance and find the best combination of feed and processes to produce salable products that meet stricter product specifications, while at the same time meeting refinery supply commitments and of course making profit. This is done through multi objective optimization. For corporate refining companies and at the national level, Intea-Refinery and Inter-Refinery optimization is the second step in optimizing the operation of the whole refining chain as a single system. Most refinery-wide optimization methods do not cover multiple objectives such as minimizing environmental impact, avoiding catastrophic failures, or enhancing product spec upgrade effects. This work starts by carrying out a refinery-wide, single objective optimization, and then moves to multi objective-single refinery optimization. The last step is multi objective-multi refinery optimization, the objectives of which are analysis of the effects of economic, environmental, product spec, strategic, and catastrophic failure. Simulation runs were carried out using both MATLAB and ASPEN PIMS utilizing nonlinear techniques to solve the optimization problem. The results addressed the need to debottleneck some refineries or transportation media in order to meet the demand for essential products under partial or total failure scenarios. They also addressed how importing some high spec products can help recover some of the losses and what is needed in order to accomplish this. In addition, the results showed nonlinear relations among local and global objectives for some refineries. The results demonstrate that refineries can have a local multi objective optimum that does not

[CT scan evaluation of the syndesmotic diastasis in AO/OTA B and C ankle fractures].

PubMed

Paredes-Vázquez, R; Sesma-Villalpando, R A; Herrera-Tenorio, G; Romero-Ogawa, T

2011-01-01

There are anatomical variants of the tibiofibular syndesmosis that lead to changes in the radiographic criteria applied to its injury. To determine the syndesmotic diastasis using CAT scan in B and C (AO/OTA) ankle fractures and relate the anatomical variants of the tibial incisure with the separation from the fibula. Comparative, cross-sectional and prolective screening that included all patients with B and C (AO/OTA) ankle fractures who completed their X-ray and CAT scan assessment. The radiographic parameters included the tibiofibular clearance, tibiofibular overlapping and the internal clearance. The length, depth and shape of the tibial incisure were measured with CAT scan. The statistical method used was the chi2. The total number of patients was 17:8 females (47%) and 9 males (53%), with a mean age of 41 years. Fourteen (82%) had a syndesmotic fracture and 3 had suprasyndesmotic fractures. The CAT scan found 10 concave incisures, 4 irregular and 3 flat ones. The mean depth of the incisure was 2.82 +/- 0.89 mm, and the mean width was 22.18 +/- 3.04. No syndesmotic diastasis was detected radiographically in 6 cases (35.2%); the CAT scan only detected 3 of them (17.7%). The diagnosis of syndesmotic diastasis was made with plain X-rays in 11 cases (64.8%) and with CAT scan in 14 (82.3%) (p = 0.043). The X-rays are questionable to define the syndesmotic diastasis, so the CAT scan should be considered in cases of a doubtful diagnosis.

DATA QUALITY OBJECTIVES AND MEASUREMENT QUALITY OBJECTIVES FOR RESEARCH PROJECTS

EPA Science Inventory

The paper provides assistance with systematic planning using measurement quality objectives to those working on research projects. These performance criteria are more familiar to researchers than data quality objectives because they are more closely associated with the measuremen...

Propelling Extended Objects

ERIC Educational Resources Information Center

Humbert, Richard

2010-01-01

A force acting on just part of an extended object (either a solid or a volume of a liquid) can cause all of it to move. That motion is due to the transmission of the force through the object by its material. This paper discusses how the force is distributed to all of the object by a gradient of stress or pressure in it, which creates the local…

Magellan Adaptive Optics First-light Observations of the Exoplanet β Pic B. I. Direct Imaging in the Far-red Optical with MagAO+VisAO and in the Near-ir with NICI

NASA Astrophysics Data System (ADS)

Males, Jared R.; Close, Laird M.; Morzinski, Katie M.; Wahhaj, Zahed; Liu, Michael C.; Skemer, Andrew J.; Kopon, Derek; Follette, Katherine B.; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Biller, Beth A.; Nielsen, Eric L.; Hinz, Philip M.; Rodigas, Timothy J.; Hayward, Thomas L.; Chun, Mark; Ftaclas, Christ; Toomey, Douglas W.; Wu, Ya-Lin

2014-05-01

We present the first ground-based CCD (λ < 1 μm) image of an extrasolar planet. Using the Magellan Adaptive Optics system's VisAO camera, we detected the extrasolar giant planet β Pictoris b in Y-short (YS , 0.985 μm), at a separation of 0.470 ± 0.''010 and a contrast of (1.63 ± 0.49) × 10-5. This detection has a signal-to-noise ratio of 4.1 with an empirically estimated upper limit on false alarm probability of 1.0%. We also present new photometry from the Gemini Near-Infrared Coronagraphic Imager instrument on the Gemini South telescope, in CH 4S,1% (1.58 μm), KS (2.18 μm), and K cont (2.27 μm). A thorough analysis of our photometry combined with previous measurements yields an estimated near-IR spectral type of L2.5 ± 1.5, consistent with previous estimates. We estimate log (L bol/L ⊙) = -3.86 ± 0.04, which is consistent with prior estimates for β Pic b and with field early-L brown dwarfs (BDs). This yields a hot-start mass estimate of 11.9 ± 0.7 M Jup for an age of 21 ± 4 Myr, with an upper limit below the deuterium burning mass. Our L bol-based hot-start estimate for temperature is T eff = 1643 ± 32 K (not including model-dependent uncertainty). Due to the large corresponding model-derived radius of R = 1.43 ± 0.02 R Jup, this T eff is ~250 K cooler than would be expected for a field L2.5 BD. Other young, low-gravity (large-radius), ultracool dwarfs and directly imaged EGPs also have lower effective temperatures than are implied by their spectral types. However, such objects tend to be anomalously red in the near-IR compared to field BDs. In contrast, β Pic b has near-IR colors more typical of an early-L dwarf despite its lower inferred temperature.

Core shift effect in blazars

NASA Astrophysics Data System (ADS)

Agarwal, A.; Mohan, P.; Gupta, Alok C.; Mangalam, A.; Volvach, A. E.; Aller, M. F.; Aller, H. D.; Gu, M. F.; Lähteenmäki, A.; Tornikoski, M.; Volvach, L. N.

2017-07-01

We studied the pc-scale core shift effect using radio light curves for three blazars, S5 0716+714, 3C 279 and BL Lacertae, which were monitored at five frequencies (ν) between 4.8 and 36.8 GHz using the University of Michigan Radio Astronomical Observatory (UMRAO), the Crimean Astrophysical Observatory (CrAO) and Metsähovi Radio Observatory for over 40 yr. Flares were Gaussian fitted to derive time delays between observed frequencies for each flare (Δt), peak amplitude (A) and their half width. Using A ∝ να, we infer α in the range of -16.67-2.41 and using Δ t ∝ ν ^{1/k_r}, we infer kr ∼ 1, employed in the context of equipartition between magnetic and kinetic energy density for parameter estimation. From the estimated core position offset (Ωrν) and the core radius (rcore), we infer that opacity model may not be valid in all cases. The mean magnetic field strengths at 1 pc (B1) and at the core (Bcore) are in agreement with previous estimates. We apply the magnetically arrested disc model to estimate black hole spins in the range of 0.15-0.9 for these blazars, indicating that the model is consistent with expected accretion mode in such sources. The power-law-shaped power spectral density has slopes -1.3 to -2.3 and is interpreted in terms of multiple shocks or magnetic instabilities.

In orbit degradation of EUV optical components in the wavelength range 10-40 nm AO 138-3

NASA Technical Reports Server (NTRS)

Delaboudiniere, J. P.; Carabetian, C.; Hochedez, J. F.

1993-01-01

A complement of EUV optical components, including mirrors and thin film filters, was flown as part of the Long Duration Exposure Facility (LDEF) AO 138-3. The most original amongst these components were multilayered interference reflectors for the 10-40 nm wavelength range. Very moderate degradation was observed for those components which were exposed to the sun. The degradation is compatible with the deposition of a few nanometers of absorbing material on the surface of the samples.

Object memory effects on figure assignment: conscious object recognition is not necessary or sufficient.

PubMed

Peterson, M A; de Gelder, B; Rapcsak, S Z; Gerhardstein, P C; Bachoud-Lévi, A

2000-01-01

In three experiments we investigated whether conscious object recognition is necessary or sufficient for effects of object memories on figure assignment. In experiment 1, we examined a brain-damaged participant, AD, whose conscious object recognition is severely impaired. AD's responses about figure assignment do reveal effects from memories of object structure, indicating that conscious object recognition is not necessary for these effects, and identifying the figure-ground test employed here as a new implicit test of access to memories of object structure. In experiments 2 and 3, we tested a second brain-damaged participant, WG, for whom conscious object recognition was relatively spared. Nevertheless, effects from memories of object structure on figure assignment were not evident in WG's responses about figure assignment in experiment 2, indicating that conscious object recognition is not sufficient for effects of object memories on figure assignment. WG's performance sheds light on AD's performance, and has implications for the theoretical understanding of object memory effects on figure assignment.

Object recognition and pose estimation of planar objects from range data

NASA Technical Reports Server (NTRS)

Pendleton, Thomas W.; Chien, Chiun Hong; Littlefield, Mark L.; Magee, Michael

1994-01-01

The Extravehicular Activity Helper/Retriever (EVAHR) is a robotic device currently under development at the NASA Johnson Space Center that is designed to fetch objects or to assist in retrieving an astronaut who may have become inadvertently de-tethered. The EVAHR will be required to exhibit a high degree of intelligent autonomous operation and will base much of its reasoning upon information obtained from one or more three-dimensional sensors that it will carry and control. At the highest level of visual cognition and reasoning, the EVAHR will be required to detect objects, recognize them, and estimate their spatial orientation and location. The recognition phase and estimation of spatial pose will depend on the ability of the vision system to reliably extract geometric features of the objects such as whether the surface topologies observed are planar or curved and the spatial relationships between the component surfaces. In order to achieve these tasks, three-dimensional sensing of the operational environment and objects in the environment will therefore be essential. One of the sensors being considered to provide image data for object recognition and pose estimation is a phase-shift laser scanner. The characteristics of the data provided by this scanner have been studied and algorithms have been developed for segmenting range images into planar surfaces, extracting basic features such as surface area, and recognizing the object based on the characteristics of extracted features. Also, an approach has been developed for estimating the spatial orientation and location of the recognized object based on orientations of extracted planes and their intersection points. This paper presents some of the algorithms that have been developed for the purpose of recognizing and estimating the pose of objects as viewed by the laser scanner, and characterizes the desirability and utility of these algorithms within the context of the scanner itself, considering data quality and

Reasoning about Function Objects

NASA Astrophysics Data System (ADS)

Nordio, Martin; Calcagno, Cristiano; Meyer, Bertrand; Müller, Peter; Tschannen, Julian

Modern object-oriented languages support higher-order implementations through function objects such as delegates in C#, agents in Eiffel, or closures in Scala. Function objects bring a new level of abstraction to the object-oriented programming model, and require a comparable extension to specification and verification techniques. We introduce a verification methodology that extends function objects with auxiliary side-effect free (pure) methods to model logical artifacts: preconditions, postconditions and modifies clauses. These pure methods can be used to specify client code abstractly, that is, independently from specific instantiations of the function objects. To demonstrate the feasibility of our approach, we have implemented an automatic prover, which verifies several non-trivial examples.

Give Me a Hand: Adult Involvement During Object Exploration Affects Object Individuation in Infancy

PubMed Central

Johnson, Kristin M.; Woods, Rebecca J.

2015-01-01

The development of object individuation, a fundamental ability that supports identification and discrimination of objects across discrete encounters, has been examined extensively by researchers. There are significant advancements in infants’ ability to individuate objects during the first year-and-a-half. Experimental work has established a timeline of object individuation abilities and revealed some mechanisms underlying this ability, however, the influence of adult assistance during object exploration has not yet been explored. The current study investigates the effect of adult involvement during object exploration on infants’ object individuation abilities. In Experiment 1a and 1b, we examined 9.5-month-old infants’ colour-based object individuation following adult-assisted multisensory object exploration. Two components of adult interaction were of particular interest: facilitation of object manipulation (grasping, rotating, and attention-getting behaviours) and social engagement (smiling, pointing, attention-getting verbalizations, and object-directed gaze). Experiment 2a and 2b assessed these components with 4.5-month-olds to examine their impact across development. The results showed that after adult-guided object exploration, both 9.5- and 4.5-month-old infants successfully individuated previously undifferentiated objects. Results of Experiments 1b and 2b provide implications for the mechanisms underlying the scaffolding influence of adult interaction during infant behaviours. PMID:28082834

Propelling Extended Objects

NASA Astrophysics Data System (ADS)

Humbert, Richard

2010-03-01

A force acting on just part of an extended object (either a solid or a volume of a liquid) can cause all of it to move. That motion is due to the transmission of the force through the object by its material. This paper discusses how the force is distributed to all of the object by a gradient of stress or pressure in it, which creates the local force that directly propels each part of the object. Those gradients resemble the ones created in objects by their weights. An example of the latter is the compressive stress in a column of a building increasing steadily toward its lower end. That gradient occurs because each horizontal section through the column supports all of the weight above it, including the load force pushing down on the column's upper end. The gradient resembles the pressure in a container of liquid increasing with depth in it. Likewise, the weight of a vertically hanging cable causes its tension and tensile stress to increase toward its upper end.

Perceptual Learning of Object Shape

PubMed Central

Golcu, Doruk; Gilbert, Charles D.

2009-01-01

Recognition of objects is accomplished through the use of cues that depend on internal representations of familiar shapes. We used a paradigm of perceptual learning during visual search to explore what features human observers use to identify objects. Human subjects were trained to search for a target object embedded in an array of distractors, until their performance improved from near-chance levels to over 80% of trials in an object specific manner. We determined the role of specific object components in the recognition of the object as a whole by measuring the transfer of learning from the trained object to other objects sharing components with it. Depending on the geometric relationship of the trained object with untrained objects, transfer to untrained objects was observed. Novel objects that shared a component with the trained object were identified at much higher levels than those that did not, and this could be used as an indicator of which features of the object were important for recognition. Training on an object also transferred to the components of the object when these components were embedded in an array of distractors of similar complexity. These results suggest that objects are not represented in a holistic manner during learning, but that their individual components are encoded. Transfer between objects was not complete, and occurred for more than one component, regardless of how well they distinguish the object from distractors. This suggests that a joint involvement of multiple components was necessary for full performance. PMID:19864574

Breaking object correspondence across saccades impairs object recognition: The role of color and luminance.

PubMed

Poth, Christian H; Schneider, Werner X

2016-09-01

Rapid saccadic eye movements bring the foveal region of the eye's retina onto objects for high-acuity vision. Saccades change the location and resolution of objects' retinal images. To perceive objects as visually stable across saccades, correspondence between the objects before and after the saccade must be established. We have previously shown that breaking object correspondence across the saccade causes a decrement in object recognition (Poth, Herwig, & Schneider, 2015). Color and luminance can establish object correspondence, but it is unknown how these surface features contribute to transsaccadic visual processing. Here, we investigated whether changing the surface features color-and-luminance and color alone across saccades impairs postsaccadic object recognition. Participants made saccades to peripheral objects, which either maintained or changed their surface features across the saccade. After the saccade, participants briefly viewed a letter within the saccade target object (terminated by a pattern mask). Postsaccadic object recognition was assessed as participants' accuracy in reporting the letter. Experiment A used the colors green and red with different luminances as surface features, Experiment B blue and yellow with approximately the same luminances. Changing the surface features across the saccade deteriorated postsaccadic object recognition in both experiments. These findings reveal a link between object recognition and object correspondence relying on the surface features colors and luminance, which is currently not addressed in theories of transsaccadic perception. We interpret the findings within a recent theory ascribing this link to visual attention (Schneider, 2013).

Object-based connectedness facilitates matching.

PubMed

Koning, Arno; van Lier, Rob

2003-10-01

In two matching tasks, participants had to match two images of object pairs. Image-based (IB) connectedness refers to connectedness between the objects in an image. Object-based (OB) connectedness refers to connectedness between the interpreted objects. In Experiment 1, a monocular depth cue (shadow) was used to distinguish different relation types between object pairs. Three relation types were created: IB/OB-connected objects, IB/OB-disconnected objects, and IB-connected/OB-disconnected objects. It was found that IB/OB-connected objects were matched faster than IB/OB-disconnected objects. Objects that were IB-connected/OB-disconnected were matched equally to IB/OB-disconnected objects. In Experiment 2, stereoscopic presentation was used. With relation types comparable to those in Experiment 1, it was again found that OB connectedness determined speed of matching, rather than IB connectedness. We conclude that matching of projections of three-dimensional objects depends more on OB connectedness than on IB connectedness.

Objects of consciousness

PubMed Central

Hoffman, Donald D.; Prakash, Chetan

2014-01-01

Current models of visual perception typically assume that human vision estimates true properties of physical objects, properties that exist even if unperceived. However, recent studies of perceptual evolution, using evolutionary games and genetic algorithms, reveal that natural selection often drives true perceptions to extinction when they compete with perceptions tuned to fitness rather than truth: Perception guides adaptive behavior; it does not estimate a preexisting physical truth. Moreover, shifting from evolutionary biology to quantum physics, there is reason to disbelieve in preexisting physical truths: Certain interpretations of quantum theory deny that dynamical properties of physical objects have definite values when unobserved. In some of these interpretations the observer is fundamental, and wave functions are compendia of subjective probabilities, not preexisting elements of physical reality. These two considerations, from evolutionary biology and quantum physics, suggest that current models of object perception require fundamental reformulation. Here we begin such a reformulation, starting with a formal model of consciousness that we call a “conscious agent.” We develop the dynamics of interacting conscious agents, and study how the perception of objects and space-time can emerge from such dynamics. We show that one particular object, the quantum free particle, has a wave function that is identical in form to the harmonic functions that characterize the asymptotic dynamics of conscious agents; particles are vibrations not of strings but of interacting conscious agents. This allows us to reinterpret physical properties such as position, momentum, and energy as properties of interacting conscious agents, rather than as preexisting physical truths. We sketch how this approach might extend to the perception of relativistic quantum objects, and to classical objects of macroscopic scale. PMID:24987382

The probability of object-scene co-occurrence influences object identification processes.

PubMed

Sauvé, Geneviève; Harmand, Mariane; Vanni, Léa; Brodeur, Mathieu B

2017-07-01

Contextual information allows the human brain to make predictions about the identity of objects that might be seen and irregularities between an object and its background slow down perception and identification processes. Bar and colleagues modeled the mechanisms underlying this beneficial effect suggesting that the brain stocks information about the statistical regularities of object and scene co-occurrence. Their model suggests that these recurring regularities could be conceptualized along a continuum in which the probability of seeing an object within a given scene can be high (probable condition), moderate (improbable condition) or null (impossible condition). In the present experiment, we propose to disentangle the electrophysiological correlates of these context effects by directly comparing object-scene pairs found along this continuum. We recorded the event-related potentials of 30 healthy participants (18-34 years old) and analyzed their brain activity in three time windows associated with context effects. We observed anterior negativities between 250 and 500 ms after object onset for the improbable and impossible conditions (improbable more negative than impossible) compared to the probable condition as well as a parieto-occipital positivity (improbable more positive than impossible). The brain may use different processing pathways to identify objects depending on whether the probability of co-occurrence with the scene is moderate (rely more on top-down effects) or null (rely more on bottom-up influences). The posterior positivity could index error monitoring aimed to ensure that no false information is integrated into mental representations of the world.

Distinct cognitive mechanisms involved in the processing of single objects and object ensembles

PubMed Central

Cant, Jonathan S.; Sun, Sol Z.; Xu, Yaoda

2015-01-01

Behavioral research has demonstrated that the shape and texture of single objects can be processed independently. Similarly, neuroimaging results have shown that an object's shape and texture are processed in distinct brain regions with shape in the lateral occipital area and texture in parahippocampal cortex. Meanwhile, objects are not always seen in isolation and are often grouped together as an ensemble. We recently showed that the processing of ensembles also involves parahippocampal cortex and that the shape and texture of ensemble elements are processed together within this region. These neural data suggest that the independence seen between shape and texture in single-object perception would not be observed in object-ensemble perception. Here we tested this prediction by examining whether observers could attend to the shape of ensemble elements while ignoring changes in an unattended texture feature and vice versa. Across six behavioral experiments, we replicated previous findings of independence between shape and texture in single-object perception. In contrast, we observed that changes in an unattended ensemble feature negatively impacted the processing of an attended ensemble feature only when ensemble features were attended globally. When they were attended locally, thereby making ensemble processing similar to single-object processing, interference was abolished. Overall, these findings confirm previous neuroimaging results and suggest that distinct cognitive mechanisms may be involved in single-object and object-ensemble perception. Additionally, they show that the scope of visual attention plays a critical role in determining which type of object processing (ensemble or single object) is engaged by the visual system. PMID:26360156

Treatment of linear mandibular fractures using a single 2.0-mm AO locking reconstruction plate: is a second plate necessary?

PubMed

Scolozzi, Paolo; Martinez, Alvaro; Jaques, Bertrand

2009-12-01

To prospectively evaluate the use of a single Arbeitsgemeinschaft für Osteosynthesefragen (AO) 2.0-mm locking reconstruction plate for linear noncomminuted mandibular fractures without the use of a second plate. We analyzed the clinical and radiologic data of 45 patients with 74 fractures (21 single fractures, 22 double fractures, and 2 triple fractures). Fracture locations were the symphysis (n = 35, 47.3%), body (n = 15, 20.3%), and angle (n = 24, 32.4%). We recorded the mechanism of injury, time between admission to the hospital and surgery, gender and age, temporary maxillomandibular fixation and its duration, and the surgical approach. Postsurgical complications that were recorded as minor did not require surgical intervention, whereas major complications required further surgical intervention. All patients had satisfactory fracture reduction and a successful treatment outcome without major complications. Ten patients (22.2%) developed minor complications. The present study has demonstrated that treating linear noncomminuted mandibular fractures with a single AO 2.0-mm locking reconstruction plates is associated with no major complications and sound bone healing in all patients.

3-D Interpolation in Object Perception: Evidence from an Objective Performance Paradigm

ERIC Educational Resources Information Center

Kellman, Philip J.; Garrigan, Patrick; Shipley, Thomas F.; Yin, Carol; Machado, Liana

2005-01-01

Object perception requires interpolation processes that connect visible regions despite spatial gaps. Some research has suggested that interpolation may be a 3-D process, but objective performance data and evidence about the conditions leading to interpolation are needed. The authors developed an objective performance paradigm for testing 3-D…

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.

Degradation of typical N-nitrosodimethylamine (NDMA) precursors and its formation potential in anoxic-aerobic (AO) activated sludge system.

PubMed

Wang, Lin; Li, Yongmei; He, Guodong

2014-01-01

N-nitrosodimethylamine (NDMA) is an emerging disinfection byproduct. Removal of its potential precursors is considered as an effective method to control NDMA. In this study, four typical NDMA precursors (dimethylamine (DMA), trimethylamine (TMA), dimethylformamide (DMFA) and dimethylaminobenzene (DMAB)) were selected, and their removal capacities by activated sludge were investigated. Batch experiments indicated that removal of NDMA precursors was better under aerobic condition than anoxic condition; and their specific degradation rates follow the order of DMA > TMA > DMFA > DMAB. In anoxic-aerobic (AO) activated sludge system, the optimal hydraulic retention time and sludge retention time were 10 h and 20 d, respectively, for the removal of both NDMA precursors (four selected NDMA precursors and NDMA formation potential (NDMA FP)) and nutrients. Our results also suggested that there was a positive correlation between NDMA FP and dissolved organic nitrogen (DON) in wastewater. The removal efficiency of NDMA FP was in the range of 46.8-72.5% in the four surveyed wastewater treatment plants except the one which adopted chemically enhanced primary process. The results revealed that the AO system had the advantage of removing NDMA FP. Our results are helpful for the knowledge of the removals of NDMA precursors during activated sludge treatment processes.

Object permanence in lemurs.

PubMed

Deppe, Anja M; Wright, Patricia C; Szelistowski, William A

2009-03-01

Object permanence, the ability to mentally represent objects that have disappeared from view, should be advantageous to animals in their interaction with the natural world. The objective of this study was to examine whether lemurs possess object permanence. Thirteen adult subjects representing four species of diurnal lemur (Eulemur fulvus rufus, Eulemur mongoz, Lemur catta and Hapalemur griseus) were presented with seven standard Piagetian visible and invisible object displacement tests, plus one single visible test where the subject had to wait predetermined times before allowed to search, and two invisible tests where each hiding place was made visually unique. In all visible tests lemurs were able to find an object that had been in clear view before being hidden. However, when lemurs were not allowed to search for up to 25-s, performance declined with increasing time-delay. Subjects did not outperform chance on any invisible displacements regardless of whether hiding places were visually uniform or unique, therefore the upper limit of object permanence observed was Stage 5b. Lemur species in this study eat stationary foods and are not subject to stalking predators, thus Stage 5 object permanence is probably sufficient to solve most problems encountered in the wild.

An Introduction to Object-Oriented Programming with a Didactic Microworld: "objectKarel"

ERIC Educational Resources Information Center

Xinogalos, Stelios; Satratzemi, Maya; Dagdilelis, Vassilios

2006-01-01

The objects-first strategy to teaching programming has prevailed over the imperative-first and functional-first strategies during the last decade. However, the objects-first strategy has created added difficulties to both the teaching and learning of programming. In an attempt to confront these difficulties and support the objects-first strategy…

Towards an Object-Oriented Model for the Design and Development of Learning Objects

ERIC Educational Resources Information Center

Chrysostomou, Chrysostomos; Papadopoulos, George

2008-01-01

This work introduces the concept of an Object-Oriented Learning Object (OOLO) that is developed in a manner similar to the one that software objects are developed through Object-Oriented Software Engineering (OO SWE) techniques. In order to make the application of the OOLO feasible and efficient, an OOLO model needs to be developed based on…

Neural Substrates of View-Invariant Object Recognition Developed without Experiencing Rotations of the Objects

PubMed Central

Okamura, Jun-ya; Yamaguchi, Reona; Honda, Kazunari; Tanaka, Keiji

2014-01-01

One fails to recognize an unfamiliar object across changes in viewing angle when it must be discriminated from similar distractor objects. View-invariant recognition gradually develops as the viewer repeatedly sees the objects in rotation. It is assumed that different views of each object are associated with one another while their successive appearance is experienced in rotation. However, natural experience of objects also contains ample opportunities to discriminate among objects at each of the multiple viewing angles. Our previous behavioral experiments showed that after experiencing a new set of object stimuli during a task that required only discrimination at each of four viewing angles at 30° intervals, monkeys could recognize the objects across changes in viewing angle up to 60°. By recording activities of neurons from the inferotemporal cortex after various types of preparatory experience, we here found a possible neural substrate for the monkeys' performance. For object sets that the monkeys had experienced during the task that required only discrimination at each of four viewing angles, many inferotemporal neurons showed object selectivity covering multiple views. The degree of view generalization found for these object sets was similar to that found for stimulus sets with which the monkeys had been trained to conduct view-invariant recognition. These results suggest that the experience of discriminating new objects in each of several viewing angles develops the partially view-generalized object selectivity distributed over many neurons in the inferotemporal cortex, which in turn bases the monkeys' emergent capability to discriminate the objects across changes in viewing angle. PMID:25378169

[Application of bone flap pedicled on retrograde branch of radial artery for treatment of old scaphoid bone fractures of type AO-B].

PubMed

Sun, Qing-peng

2015-05-01

To investigate application of the bone flap pedicled on the retrograde branch of radial artery for treatment of old scaphoid bone fractures of type AO-B. From October 2007 to October 2011,41 patients with old scaphoid bone fractures of type AO-B were treated by transplantation of the bone flap pedicled on the retrograde branch of radial artery including 26 males and 15 females with an average of (27.3±4.5) years old ranging from 16 to 43 years old. The courses before operation ranged from 6 to 22 months with an average of 11 months. All fractures belonged to the type B of AO classification, that is old wrist fracture of scaphoid bone. All patients' wrist function (pain, function, motion, grip strength) were evaluated by Cooney's modifiedwrist scoring system before and 6 months after operation,and the conditions of bone healing were observed during the follow-up time. Among them, 36 patients were followed up from 4 to 15 months with an average of 8.3 months. The wounds were healed well without other complications as infection appearing. X-rays or CT confirmed that all fractures were healed completely. The Cooney wrist score was improved from preoperative 53.61±13.97 to postoperative 81.81±8.71 (P<0.01). The operation of transplantation of the bone flap pedicled on the retrograde branch of radial artery is an effective method to treat old scaphoid bone fractures,which is scientific and has curative effects, and valuable for clinical application.

Neural substrates of view-invariant object recognition developed without experiencing rotations of the objects.

PubMed

Okamura, Jun-Ya; Yamaguchi, Reona; Honda, Kazunari; Wang, Gang; Tanaka, Keiji

2014-11-05

One fails to recognize an unfamiliar object across changes in viewing angle when it must be discriminated from similar distractor objects. View-invariant recognition gradually develops as the viewer repeatedly sees the objects in rotation. It is assumed that different views of each object are associated with one another while their successive appearance is experienced in rotation. However, natural experience of objects also contains ample opportunities to discriminate among objects at each of the multiple viewing angles. Our previous behavioral experiments showed that after experiencing a new set of object stimuli during a task that required only discrimination at each of four viewing angles at 30° intervals, monkeys could recognize the objects across changes in viewing angle up to 60°. By recording activities of neurons from the inferotemporal cortex after various types of preparatory experience, we here found a possible neural substrate for the monkeys' performance. For object sets that the monkeys had experienced during the task that required only discrimination at each of four viewing angles, many inferotemporal neurons showed object selectivity covering multiple views. The degree of view generalization found for these object sets was similar to that found for stimulus sets with which the monkeys had been trained to conduct view-invariant recognition. These results suggest that the experience of discriminating new objects in each of several viewing angles develops the partially view-generalized object selectivity distributed over many neurons in the inferotemporal cortex, which in turn bases the monkeys' emergent capability to discriminate the objects across changes in viewing angle. Copyright © 2014 the authors 0270-6474/14/3415047-13$15.00/0.

Gamifying Video Object Segmentation.

PubMed

Spampinato, Concetto; Palazzo, Simone; Giordano, Daniela

2017-10-01

Video object segmentation can be considered as one of the most challenging computer vision problems. Indeed, so far, no existing solution is able to effectively deal with the peculiarities of real-world videos, especially in cases of articulated motion and object occlusions; limitations that appear more evident when we compare the performance of automated methods with the human one. However, manually segmenting objects in videos is largely impractical as it requires a lot of time and concentration. To address this problem, in this paper we propose an interactive video object segmentation method, which exploits, on one hand, the capability of humans to identify correctly objects in visual scenes, and on the other hand, the collective human brainpower to solve challenging and large-scale tasks. In particular, our method relies on a game with a purpose to collect human inputs on object locations, followed by an accurate segmentation phase achieved by optimizing an energy function encoding spatial and temporal constraints between object regions as well as human-provided location priors. Performance analysis carried out on complex video benchmarks, and exploiting data provided by over 60 users, demonstrated that our method shows a better trade-off between annotation times and segmentation accuracy than interactive video annotation and automated video object segmentation approaches.

Ultrathin zoom telescopic objective.

PubMed

Li, Lei; Wang, Di; Liu, Chao; Wang, Qiong-Hua

2016-08-08

We report an ultrathin zoom telescopic objective that can achieve continuous zoom change and has reduced compact volume. The objective consists of an annular folded lens and three electrowetting liquid lenses. The annular folded lens undertakes the main part of the focal power of the lens system. Due to a multiple-fold design, the optical path is folded in a lens with the thickness of ~1.98mm. The electrowetting liquid lenses constitute a zoom part. Based on the proposed objective, an ultrathin zoom telescopic camera is demonstrated. We analyze the properties of the proposed objective. The aperture of the proposed objective is ~15mm. The total length of the system is ~18mm with a tunable focal length ~48mm to ~65mm. Compared with the conventional zoom telescopic objective, the total length has been largely reduced.

Space Object Query Tool

NASA Technical Reports Server (NTRS)

Phillips, Veronica J.

2017-01-01

STI is for a fact sheet on the Space Object Query Tool being created by the MDC. When planning launches, NASA must first factor in the tens of thousands of objects already in orbit around the Earth. The number of human-made objects, including nonfunctional spacecraft, abandoned launch vehicle stages, mission-related debris and fragmentation debris orbiting Earth has grown steadily since Sputnik 1 was launched in 1957. Currently, the U.S. Department of Defenses Joint Space Operations Center, or JSpOC, tracks over 15,000 distinct objects and provides data for more than 40,000 objects via its Space-Track program, found at space-track.org.

Object similarity affects the perceptual strategy underlying invariant visual object recognition in rats

PubMed Central

Rosselli, Federica B.; Alemi, Alireza; Ansuini, Alessio; Zoccolan, Davide

2015-01-01

In recent years, a number of studies have explored the possible use of rats as models of high-level visual functions. One central question at the root of such an investigation is to understand whether rat object vision relies on the processing of visual shape features or, rather, on lower-order image properties (e.g., overall brightness). In a recent study, we have shown that rats are capable of extracting multiple features of an object that are diagnostic of its identity, at least when those features are, structure-wise, distinct enough to be parsed by the rat visual system. In the present study, we have assessed the impact of object structure on rat perceptual strategy. We trained rats to discriminate between two structurally similar objects, and compared their recognition strategies with those reported in our previous study. We found that, under conditions of lower stimulus discriminability, rat visual discrimination strategy becomes more view-dependent and subject-dependent. Rats were still able to recognize the target objects, in a way that was largely tolerant (i.e., invariant) to object transformation; however, the larger structural and pixel-wise similarity affected the way objects were processed. Compared to the findings of our previous study, the patterns of diagnostic features were: (i) smaller and more scattered; (ii) only partially preserved across object views; and (iii) only partially reproducible across rats. On the other hand, rats were still found to adopt a multi-featural processing strategy and to make use of part of the optimal discriminatory information afforded by the two objects. Our findings suggest that, as in humans, rat invariant recognition can flexibly rely on either view-invariant representations of distinctive object features or view-specific object representations, acquired through learning. PMID:25814936

Bats' avoidance of real and virtual objects: implications for the sonar coding of object size.

PubMed

Goerlitz, Holger R; Genzel, Daria; Wiegrebe, Lutz

2012-01-01

Fast movement in complex environments requires the controlled evasion of obstacles. Sonar-based obstacle evasion involves analysing the acoustic features of object-echoes (e.g., echo amplitude) that correlate with this object's physical features (e.g., object size). Here, we investigated sonar-based obstacle evasion in bats emerging in groups from their day roost. Using video-recordings, we first show that the bats evaded a small real object (ultrasonic loudspeaker) despite the familiar flight situation. Secondly, we studied the sonar coding of object size by adding a larger virtual object. The virtual object echo was generated by real-time convolution of the bats' calls with the acoustic impulse response of a large spherical disc and played from the loudspeaker. Contrary to the real object, the virtual object did not elicit evasive flight, despite the spectro-temporal similarity of real and virtual object echoes. Yet, their spatial echo features differ: virtual object echoes lack the spread of angles of incidence from which the echoes of large objects arrive at a bat's ears (sonar aperture). We hypothesise that this mismatch of spectro-temporal and spatial echo features caused the lack of virtual object evasion and suggest that the sonar aperture of object echoscapes contributes to the sonar coding of object size. Copyright © 2011 Elsevier B.V. All rights reserved.

Tracking multiple objects is limited only by object spacing, not by speed, time, or capacity.

PubMed

Franconeri, S L; Jonathan, S V; Scimeca, J M

2010-07-01

In dealing with a dynamic world, people have the ability to maintain selective attention on a subset of moving objects in the environment. Performance in such multiple-object tracking is limited by three primary factors-the number of objects that one can track, the speed at which one can track them, and how close together they can be. We argue that this last limit, of object spacing, is the root cause of all performance constraints in multiple-object tracking. In two experiments, we found that as long as the distribution of object spacing is held constant, tracking performance is unaffected by large changes in object speed and tracking time. These results suggest that barring object-spacing constraints, people could reliably track an unlimited number of objects as fast as they could track a single object.

Visual object recognition and tracking

NASA Technical Reports Server (NTRS)

Chang, Chu-Yin (Inventor); English, James D. (Inventor); Tardella, Neil M. (Inventor)

2010-01-01

This invention describes a method for identifying and tracking an object from two-dimensional data pictorially representing said object by an object-tracking system through processing said two-dimensional data using at least one tracker-identifier belonging to the object-tracking system for providing an output signal containing: a) a type of the object, and/or b) a position or an orientation of the object in three-dimensions, and/or c) an articulation or a shape change of said object in said three dimensions.

Complex Spiral Structure in the HD 100546 Transitional Disk as Revealed by GPI and MagAO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Follette, Katherine B.; Macintosh, Bruce; Mullen, Wyatt

We present optical and near-infrared high-contrast images of the transitional disk HD 100546 taken with the Magellan Adaptive Optics system (MagAO) and the Gemini Planet Imager (GPI). GPI data include both polarized intensity and total intensity imagery, and MagAO data are taken in Simultaneous Differential Imaging mode at H α . The new GPI H -band total intensity data represent a significant enhancement in sensitivity and field rotation compared to previous data sets and enable a detailed exploration of substructure in the disk. The data are processed with a variety of differential imaging techniques (polarized, angular, reference, and simultaneous differentialmore » imaging) in an attempt to identify the disk structures that are most consistent across wavelengths, processing techniques, and algorithmic parameters. The inner disk cavity at 15 au is clearly resolved in multiple data sets, as are a variety of spiral features. While the cavity and spiral structures are identified at levels significantly distinct from the neighboring regions of the disk under several algorithms and with a range of algorithmic parameters, emission at the location of HD 100546 “ c ” varies from point-like under aggressive algorithmic parameters to a smooth continuous structure with conservative parameters, and is consistent with disk emission. Features identified in the HD 100546 disk bear qualitative similarity to computational models of a moderately inclined two-armed spiral disk, where projection effects and wrapping of the spiral arms around the star result in a number of truncated spiral features in forward-modeled images.« less

Direct RF A-O Processor Spectrum Analyzer.

DTIC Science & Technology

1981-08-01

The primary objective was to develop and demonstrate design approach, along with the associated processing technologies, for a wideband acousto optic Bragg...cell spectrum analyzer. The signal processor used to demonstrate feasibility of the technical approach consisted of two bulk wave acousto optic deflectors

Credit assignment between body and object probed by an object transportation task.

PubMed

Kong, Gaiqing; Zhou, Zhihao; Wang, Qining; Kording, Konrad; Wei, Kunlin

2017-10-17

It has been proposed that learning from movement errors involves a credit assignment problem: did I misestimate properties of the object or those of my body? For example, an overestimate of arm strength and an underestimate of the weight of a coffee cup can both lead to coffee spills. Though previous studies have found signs of simultaneous learning of the object and of the body during object manipulation, there is little behavioral evidence about their quantitative relation. Here we employed a novel weight-transportation task, in which participants lift the first cup filled with liquid while assessing their learning from errors. Specifically, we examined their transfer of learning when switching to a contralateral hand, the second identical cup, or switching both hands and cups. By comparing these transfer behaviors, we found that 25% of the learning was attributed to the object (simply because of the use of the same cup) and 58% of the learning was attributed to the body (simply because of the use of the same hand). The nervous system thus seems to partition the learning of object manipulation between the object and the body.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determinação de regiões de órbitas diretas estáveis ao redor da Lua

NASA Astrophysics Data System (ADS)

de Melo, C. F.; Winter, O. C.; Vieira Neto, E.

2003-08-01

Neste Trabalho estamos investigando regiões do sistema Terra-Lua que contêm órbitas diretas estáveis ao redor da Lua visando a utilização destas órbitas em futuras missões de veículos espaciais como alternativas de trajetórias com baixo custo de manutenção. Adotando-se o problema restrito de três corpos, Terra-Lua-partícula, a localização e a extensão destas regiões de estabilidade foram investigadas numericamente considerando como estável toda órbita que permanece ao redor a Lua por, no mínimo, 1000 dias com energia de dois corpos da partícula em relação à Lua negativa. A estabilidade de tais regiões está associada a duas famílias de órbitas periódicas simples H1 e H2 e a órbitas quase-periódicas associadas a elas. Uma vez identificadas as regiões de estabilidade passamos a analisá-las introduzindo, paulatinamente, outras interações relevantes ao sistema como as perturbações do Sol (via problema restrito de quatro corpos), das marés, da pressão de radiação e do achatamento terrestre. Os resultados encontrados até o momento mostram que a perturbação do Sol é a única que reduz significativamente o tamanho das regiões de estabilidade. Também estamos investigando o comportamento de tais regiões quando características intrínsecas do sistema como as excentricidades das órbitas da Terra e da Lua e a inclinação da órbita Lua são consideradas. Com este estudo estamos reunindo informações que nos permitirão compreender a evolução das regiões de estabilidade no sistema Terra-Lua, bem como estabelecer parâmetros adequados para a utilização das trajetórias estáveis em futuras missões espaciais. Agradecimentos: Este projeto conta com o apoio do CNPq, da Capes e da Fapesp.

Learning Objects and Gerontology

ERIC Educational Resources Information Center

Weinreich, Donna M.; Tompkins, Catherine J.

2006-01-01

Virtual AGE (vAGE) is an asynchronous educational environment that utilizes learning objects focused on gerontology and a learning anytime/anywhere philosophy. This paper discusses the benefits of asynchronous instruction and the process of creating learning objects. Learning objects are "small, reusable chunks of instructional media" Wiley…

Carpentry Performance Objectives.

ERIC Educational Resources Information Center

Day, Gerald F.; Tucker, John

The guidelines for carpentry performance objectives were written for vocational educators in order to insure that their programs are fulfilling the training requirements of today's job market. The document outlines eight uses of performance objectives and provides sample employability profiles, training achievement records, and a carpentry…

Music Objectives: Second Assessment.

ERIC Educational Resources Information Center

Education Commission of the States, Denver, CO. National Assessment of Educational Progress.

The document describes the development of objectives and presents objectives formulated by music educators, lay individuals, and the National Assessment of Educational Progress (NAEP) staff in 1973. Objectives from the first music assessment were reappraised, reviewed, and revised to include greater breadth of application, greater emphasis on the…

Moving Object Control System

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey (Inventor); Carl, James R. (Inventor)

2001-01-01

A method is provided for controlling two objects relatively moveable with respect to each other. A plurality of receivers are provided for detecting a distinctive microwave signal from each of the objects and measuring the phase thereof with respect to a reference signal. The measured phase signal is used to determine a distance between each of the objects and each of the plurality of receivers. Control signals produced in response to the relative distances are used to control the position of the two objects.

Objects of Desire.

ERIC Educational Resources Information Center

Zielinski, Dave

2000-01-01

Describes learning objects, also known as granules, chunks, or information nuggets, and likens them to help screens. Discusses concerns about how they can go wrong: (1) faulty pretest questions; (2) missing links in the learning object chain; (3) poor frames of reference; and (4) lack of customization. (JOW)

Examining object recognition and object-in-Place memory in plateau zokors, Eospalax baileyi.

PubMed

Hegab, Ibrahim M; Tan, Yuchen; Wang, Chan; Yao, Baohui; Wang, Haifang; Ji, Weihong; Su, Junhu

2018-01-01

Recognition memory is important for the survival and fitness of subterranean rodents due to the barren underground conditions that require avoiding the burden of higher energy costs or possible conflict with conspecifics. Our study aims to examine the object and object/place recognition memories in plateau zokors (Eospalax baileyi) and test whether their underground life exerts sex-specific differences in memory functions using Novel Object Recognition (NOR) and Object-in-Place (OiP) paradigms. Animals were tested in the NOR with short (10min) and long-term (24h) inter-trial intervals (ITI) and in the OiP for a 30-min ITI between the familiarization and testing sessions. Plateau zokors showed a strong preference for novel objects manifested by a longer exploration time for the novel object after 10min ITI but failed to remember the familiar object when tested after 24h, suggesting a lack of long-term memory. In the OiP test, zokors effectively formed an association between the objects and the place where they were formerly encountered, resulting in a higher duration of exploration to the switched objects. However, both sexes showed equivalent results in exploration time during the NOR and OiP tests, which eliminates the possibility of discovering sex-specific variations in memory performance. Taken together, our study illustrates robust novelty preference and an effective short-term recognition memory without marked sex-specific differences, which might elucidate the dynamics of recognition memory formation and retrieval in plateau zokors. Copyright © 2017 Elsevier B.V. All rights reserved.

3-d interpolation in object perception: evidence from an objective performance paradigm.

PubMed

Kellman, Philip J; Garrigan, Patrick; Shipley, Thomas F; Yin, Carol; Machado, Liana

2005-06-01

Object perception requires interpolation processes that connect visible regions despite spatial gaps. Some research has suggested that interpolation may be a 3-D process, but objective performance data and evidence about the conditions leading to interpolation are needed. The authors developed an objective performance paradigm for testing 3-D interpolation and tested a new theory of 3-D contour interpolation, termed 3-D relatability. The theory indicates for a given edge which orientations and positions of other edges in space may be connected to it by interpolation. Results of 5 experiments showed that processing of orientation relations in 3-D relatable displays was superior to processing in 3-D nonrelatable displays and that these effects depended on object formation. 3-D interpolation and 3-D relatabilty are discussed in terms of their implications for computational and neural models of object perception, which have typically been based on 2-D-orientation-sensitive units. ((c) 2005 APA, all rights reserved).

Asteroid (16) Psyche: Triaxial Ellipsoid Dimensions and Rotational Pole from Keck II NIRC2 AO Images and Keck I OSIRIS Images

NASA Astrophysics Data System (ADS)

Drummond, Jack D.; Conrad, Al; Reddy, Vishnu; de Kleer, Katherine R.; Adamkovics, Mate; de Pater, Imke; Merline, William J.; Tamblyn, Peter

2016-10-01

Adaptive optics (AO) images of asteroid (16) Psyche obtained at 4 epochs with the NIRC2 camera at the 10m W. M. Keck Observatory (Keck II) on UT 2015 December 25 lead to triaxial ellipsoid diameters of 279±4 x 230±2 x 195±14 km, and a rotational pole at RA=29° and Dec=-2°. Adding 6 more epochs obtained nearly simultaneously with the OSIRIS system at Keck I, as well as two more epochs from Keck II in 2009, yields diameters of 273±2 x 232±2 x 165±3 km, and a pole at RA=37° and Dec=+1°. (Errors are formal fit parameter uncertainties; an additional 4% uncertainty is possible from systematic biases.) The differing perspectives between 2015 (sub-Earth latitude Θ=-50°) and 2009 (Θ=-6°) improves primarily the c dimension and the location of the rotational pole, but illustrates how well images from even a single night can determine the size, shape, and pole of an asteroid. The 2015 observations were obtained as part of a campaign to study Psyche with many techniques over a few months, including radar from Arecibo and images from Magellan.These handful of images show the same rugged outline as the radius vector model available on the DAMIT website, constructed from many lightcurves and scaled by previous Keck AO images. In fact Psyche has rotated some 125,350 times between the first lightcurve in 1955 and our 2015 AO images, exactly 60 years apart to the day. Since the asteroid has such a high obliquity, these lightcurves have scanned well into both northern and southern hemispheres. The difference between the pole derived from our images and the radius vector model pole is only 7°, and the mean diameters of Psyche are 219 and 211 km, respectively.

Behavioral Objectives for English

ERIC Educational Resources Information Center

Zoellner, Robert

1972-01-01

A review-critique of On Writing Behavioral Objectives for English, by John Maxwell and Anthony Lovat, in which behavioral objectives theory is dominated by a stimulus-response rather than a stimulus-response-reinforcement psychology. The reviewer questions whether behavioral objectives can be applied accurately and without distortion of meanings,…

Zero-Copy Objects System

NASA Technical Reports Server (NTRS)

Burleigh, Scott C.

2011-01-01

Zero-Copy Objects System software enables application data to be encapsulated in layers of communication protocol without being copied. Indirect referencing enables application source data, either in memory or in a file, to be encapsulated in place within an unlimited number of protocol headers and/or trailers. Zero-copy objects (ZCOs) are abstract data access representations designed to minimize I/O (input/output) in the encapsulation of application source data within one or more layers of communication protocol structure. They are constructed within the heap space of a Simple Data Recorder (SDR) data store to which all participating layers of the stack must have access. Each ZCO contains general information enabling access to the core source data object (an item of application data), together with (a) a linked list of zero or more specific extents that reference portions of this source data object, and (b) linked lists of protocol header and trailer capsules. The concatenation of the headers (in ascending stack sequence), the source data object extents, and the trailers (in descending stack sequence) constitute the transmitted data object constructed from the ZCO. This scheme enables a source data object to be encapsulated in a succession of protocol layers without ever having to be copied from a buffer at one layer of the protocol stack to an encapsulating buffer at a lower layer of the stack. For large source data objects, the savings in copy time and reduction in memory consumption may be considerable.

Sex and spatial position effects on object location memory following intentional learning of object identities.

PubMed

Alexander, Gerianne M; Packard, Mark G; Peterson, Bradley S

2002-01-01

Memory for object location relative both to veridical center (left versus right visual hemispace) and to eccentricity (central versus peripheral objects) was measured in 26 males and 25 females using the Silverman and Eals Location Memory Task. A subset of participants (17 males and 13 females) also completed a measure of implicit learning, the mirror-tracing task. No sex differences were observed in memory for object identities. Further, in both sexes, memory for object locations was better for peripherally located objects than for centrally located objects. In contrast to these similarities in female and male task performance, females but not males showed better recovery of object locations in the right compared to the left visual hemispace. Moreover, memory for object locations in the right hemispace was associated with mirror-tracing performance in women but not in men. Together, these data suggest that the processing of object features and object identification in the left cerebral hemisphere may include processing of spatial information that may contribute to superior object location memory in females relative to males.

What's the object of object working memory in infancy? Unraveling 'what' and 'how many'.

PubMed

Kibbe, Melissa M; Leslie, Alan M

2013-06-01

Infants have a bandwidth-limited object working memory (WM) that can both individuate and identify objects in a scene, (answering 'how many?' or 'what?', respectively). Studies of infants' WM for objects have typically looked for limits on either 'how many' or 'what', yielding different estimates of infant capacity. Infants can keep track of about three individuals (regardless of identity), but appear to be much more limited in the number of specific identities they can recall. Why are the limits on 'how many' and 'what' different? Are the limits entirely separate, do they interact, or are they simply two different aspects of the same underlying limit? We sought to unravel these limits in a series of experiments which tested 9- and 12-month-olds' WM for object identities under varying degrees of difficulty. In a violation-of-expectation looking-time task, we hid objects one at a time behind separate screens, and then probed infants' WM for the shape identity of the penultimate object in the sequence. We manipulated the difficulty of the task by varying both the number of objects in hiding locations and the number of means by which infants could detect a shape change to the probed object. We found that 9-month-olds' WM for identities was limited by the number of hiding locations: when the probed object was one of two objects hidden (one in each of two locations), 9-month-olds succeeded, and they did so even though they were given only one means to detect the change. However, when the probed object was one of three objects hidden (one in each of three locations), they failed, even when they were given two means to detect the shape change. Twelve-month-olds, by contrast, succeeded at the most difficult task level. Results show that WM for 'how many' and for 'what' are not entirely separate. Individuated objects are tracked relatively cheaply. Maintaining bindings between indexed objects and identifying featural information incurs a greater attentional/memory cost

An in vitro biomechanical comparison of hydroxyapatite coated and uncoated ao cortical bone screws for a limited contact: dynamic compression plate fixation of osteotomized equine 3rd metacarpal bones.

PubMed

Durham, Myra E; Sod, Gary A; Riggs, Laura M; Mitchell, Colin F

2015-02-01

To compare the monotonic biomechanical properties of a broad 4.5 mm limited contact-dynamic compression plate (LC-DCP) fixation secured with hydroxyapatite (HA) coated cortical bone screws (HA-LC-DCP) versus uncoated cortical bone screws (AO-LC-DCP) to repair osteotomized equine 3rd metacarpal (MC3) bones. Experimental. Adult equine cadaveric MC3 bones (n = 12 pair). Twelve pairs of equine MC3 were divided into 3 test groups (4 pairs each) for: (1) 4 point bending single cycle to failure testing; (2) 4 point bending cyclic fatigue testing; and (3) torsional single cycle to failure testing. For the HA-LC-DCP-MC3 construct, an 8-hole broad LC-DCP (Synthes Ltd, Paoli, PA) was secured on the dorsal surface of each randomly selected MC3 bone with a combination of four 5.5 mm and four 4.5 mm HA-coated cortical screws. For the AO-LC-DCP-MC3 construct, an 8-hole 4.5 mm broad LC-DCP was secured on the dorsal surface of the contralateral MC3 bone with a combination of four 5.5 mm and four 4.5 mm uncoated cortical screws. All MC3 bones had mid-diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t-test within each group. Significance was set at P < .05. Mean yield load, yield bending moment, composite rigidity, failure load, and failure bending moment, under 4 point bending, single cycle to failure, of the HA-LC-DCP fixation were significantly greater than those of the AO-LC-DCP fixation. Mean ± SD values for the HA-LC-DCP and the AO-LC-DCP fixation techniques, respectively, in single cycle to failure under 4 point bending were: yield load, 26.7 ± 2.15 and 16.3 ± 1.38 kN; yield bending moment, 527.4 ± 42.4 and 322.9 ± 27.2 N-m; composite rigidity, 5306 ± 399 and 3003 ± 300 N-m/rad; failure load, 40.6 ± 3.94 and 26.5 ± 2.52 kN; and failure bending moment, 801.9 ± 77.9 and 522.9 ± 52.2 N-m. Mean cycles to failure in 4 point bending of the HA

Presentation on Instructional Objectives

ERIC Educational Resources Information Center

Naz, Bibi Asia

2009-01-01

"Learning can be defined as change in a student's capacity for performance as a result of experience" (Kenneth D. Moore). The intended changes should be specified in instructional objectives. Viewed in this context, an objective can be defined as a clear and unambiguous description of your instructional intent. An objective is not a…

Media Objectives for Teachers.

ERIC Educational Resources Information Center

Arrasjid, Harun, Ed.; Arrasjid, Dorine, Ed.

The purpose of this book is to provide a compendium of instructional objectives concerning instructional media and materials. It is useful for either teacher training programs or college level media courses. Each objective is stated behaviorally, such as "list the important features of a tape recorder." Objectives are arranged by medium. The media…

The Development of Invariant Object Recognition Requires Visual Experience with Temporally Smooth Objects

ERIC Educational Resources Information Center

Wood, Justin N.; Wood, Samantha M. W.

2018-01-01

How do newborns learn to recognize objects? According to temporal learning models in computational neuroscience, the brain constructs object representations by extracting smoothly changing features from the environment. To date, however, it is unknown whether newborns depend on smoothly changing features to build invariant object representations.…

Examining Object Location and Object Recognition Memory in Mice

PubMed Central

Vogel-Ciernia, Annie; Wood, Marcelo A.

2014-01-01

Unit Introduction The ability to store and recall our life experiences defines a person's identity. Consequently, the loss of long-term memory is a particularly devastating part of a variety of cognitive disorders, diseases and injuries. There is a great need to develop therapeutics to treat memory disorders, and thus a variety of animal models and memory paradigms have been developed. Mouse models have been widely used both to study basic disease mechanisms and to evaluate potential drug targets for therapeutic development. The relative ease of genetic manipulation of Mus musculus has led to a wide variety of genetically altered mice that model cognitive disorders ranging from Alzheimer's disease to autism. Rodents, including mice, are particularly adept at encoding and remembering spatial relationships, and these long-term spatial memories are dependent on the medial temporal lobe of the brain. These brain regions are also some of the first and most heavily impacted in disorders of human memory including Alzheimer's disease. Consequently, some of the simplest and most commonly used tests of long-term memory in mice are those that examine memory for objects and spatial relationships. However, many of these tasks, such as Morris water maze and contextual fear conditioning, are dependent upon the encoding and retrieval of emotionally aversive and inherently stressful training events. While these types of memories are important, they do not reflect the typical day-to-day experiences or memories most commonly affected in human disease. In addition, stress hormone release alone can modulate memory and thus obscure or artificially enhance these types of tasks. To avoid these sorts of confounds, we and many others have utilized tasks testing animals’ memory for object location and novel object recognition. These tasks involve exploiting rodents’ innate preference for novelty, and are inherently not stressful. In this protocol we detail how memory for object location

Objectivity in Quantum Measurement

NASA Astrophysics Data System (ADS)

Li, Sheng-Wen; Cai, C. Y.; Liu, X. F.; Sun, C. P.

2018-06-01

The objectivity is a basic requirement for the measurements in the classical world, namely, different observers must reach a consensus on their measurement results, so that they believe that the object exists "objectively" since whoever measures it obtains the same result. We find that this simple requirement of objectivity indeed imposes an important constraint upon quantum measurements, i.e., if two or more observers could reach a consensus on their quantum measurement results, their measurement basis must be orthogonal vector sets. This naturally explains why quantum measurements are based on orthogonal vector basis, which is proposed as one of the axioms in textbooks of quantum mechanics. The role of the macroscopicality of the observers in an objective measurement is discussed, which supports the belief that macroscopicality is a characteristic of classicality.

Objectivity in Quantum Measurement

NASA Astrophysics Data System (ADS)

Li, Sheng-Wen; Cai, C. Y.; Liu, X. F.; Sun, C. P.

2018-05-01

The objectivity is a basic requirement for the measurements in the classical world, namely, different observers must reach a consensus on their measurement results, so that they believe that the object exists "objectively" since whoever measures it obtains the same result. We find that this simple requirement of objectivity indeed imposes an important constraint upon quantum measurements, i.e., if two or more observers could reach a consensus on their quantum measurement results, their measurement basis must be orthogonal vector sets. This naturally explains why quantum measurements are based on orthogonal vector basis, which is proposed as one of the axioms in textbooks of quantum mechanics. The role of the macroscopicality of the observers in an objective measurement is discussed, which supports the belief that macroscopicality is a characteristic of classicality.

Connection-based and object-based grouping in multiple-object tracking: A developmental study.

PubMed

Van der Hallen, Ruth; Reusens, Julie; Evers, Kris; de-Wit, Lee; Wagemans, Johan

2018-03-30

Developmental research on Gestalt laws has previously revealed that, even as young as infancy, we are bound to group visual elements into unitary structures in accordance with a variety of organizational principles. Here, we focus on the developmental trajectory of both connection-based and object-based grouping, and investigate their impact on object formation in participants, aged 9-21 years old (N = 113), using a multiple-object tracking paradigm. Results reveal a main effect of both age and grouping type, indicating that 9- to 21-year-olds are sensitive to both connection-based and object-based grouping interference, and tracking ability increases with age. In addition to its importance for typical development, these results provide an informative baseline to understand clinical aberrations in this regard. Statement of contribution What is already known on this subject? The origin of the Gestalt principles is still an ongoing debate: Are they innate, learned over time, or both? Developmental research has revealed how each Gestalt principle has its own trajectory and unique relationship to visual experience. Both connectedness and object-based grouping play an important role in object formation during childhood. What does this study add? The study identifies how sensitivity to connectedness and object-based grouping evolves in individuals, aged 9-21 years old. Using multiple-object tracking, results reveal that the ability to track multiple objects increases with age. These results provide an informative baseline to understand clinical aberrations in different types of grouping. © 2018 The Authors. British Journal of Developmental Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

DNA repair properties of Escherichia coli tif-1, recAo281 and lexA1 strains deficient in single-strand DNA binding protein.

PubMed

Whittier, R F; Chase, J W

1983-01-01

Mutations affecting single-strand DNA binding protein (SSB) impair induction of mutagenic (SOS) repair. To further investigate the role of SSB in SOS induction and DNA repair, isogenic strains were constructed combining the ssb+, ssb-1 or ssb-113 alleles with one or more mutations known to alter regulation of damage inducible functions. As is true in ssb+ strains tif-1 (recA441) was found to allow thermal induction of prophage lambda + and Weigle reactivation in ssb-1 and ssb-113 strains. Furthermore, tif-1 decreased the UV sensitivity of the ssb-113 strain slightly and permitted UV induction of prophage lambda + at 30 degrees C. Strains carrying the recAo281 allele were also constructed. This mutation causes high constitutive levels of RecA protein synthesis and relieves much of the UV sensitivity conferred by lexA- alleles without restoring SOS (error-prone) repair. In contrast, the recAo281 allele failed to alleviate the UV sensitivity associated with either ssb- mutation. In a lexA1 recAo281 background the ssb-1 mutation increased the extent of postirradiation DNA degradation and concommitantly increased UV sensitivity 20-fold to the level exhibited by a recA1 strain. The ssb-113 mutation also increased UV sensitivity markedly in this background but did so without greatly increasing postirradiation DNA degradation. These results suggest a direct role for SSB in recombinational repair apart from and in addition to its role in facilitating induction of the recA-lexA regulon.

CONSTRAINTS ON THE INTERGALACTIC MAGNETIC FIELD WITH GAMMA-RAY OBSERVATIONS OF BLAZARS

DOE PAGES

Finke, Justin D.; Reyes, Luis C.; Georganopoulos, Markos; ...

2015-11-12

Distant BL Lacertae objects emit γ rays which interact with the extragalactic background light (EBL), creating electron-positron pairs, and reducing the flux measured by ground-based imaging atmospheric Cherenkov telescopes (IACTs) at very-high energies (VHE). These pairs can Comptonscatter the cosmic microwave background, creating a γ-ray signature at slightly lower energies observable by the Fermi Large Area Telescope (LAT). This signal is strongly dependent on the intergalactic magnetic field (IGMF) strength (B) and its coherence length (LB). We use IACT spectra taken from the literature for 5 VHE-detected BL Lac objects, and combine it with LAT spectra for these sources tomore » constrain these IGMF parameters. Low B values can be ruled out by the constraint that the cascade flux cannot exceed that observed by the LAT. High values of B can be ruled out from the constraint that the EBL-deabsorbed IACT spectrum cannot be greater than the LAT spectrum extrapolated into the VHE band, unless the cascade spectrum contributes a sizable fraction of the LAT flux. We rule out low B values (B . 10 -19 G for LB ≥ 1 Mpc) at > 5σ in all trials with different EBL models and data selection, except when« less

The Language of Objection

ERIC Educational Resources Information Center

Duffy, Francis M.

2010-01-01

Whenever the author talks to audiences about transforming school systems, without exception people raise objections. The half dozen most common objections often come in the form of "Yes, nice idea but..." What follows the "but" is the objection. The author learned a technique for responding to these "buts" from family members who work in sales.…

On the Crime Object

ERIC Educational Resources Information Center

Akutaev, Rasul M.; Magomedov, Guseyn B.

2016-01-01

The relevance of the research of this problem is caused by the theoretical and practical needs of a specific concept of the crime object as one of the corpus delicti signs essentially the determining and defining its object and objective side, thereby--the nature of socially dangerous act. Besides, being a facultative sign of corpus delicti, the…

How learning might strengthen existing visual object representations in human object-selective cortex.

PubMed

Brants, Marijke; Bulthé, Jessica; Daniels, Nicky; Wagemans, Johan; Op de Beeck, Hans P

2016-02-15

Visual object perception is an important function in primates which can be fine-tuned by experience, even in adults. Which factors determine the regions and the neurons that are modified by learning is still unclear. Recently, it was proposed that the exact cortical focus and distribution of learning effects might depend upon the pre-learning mapping of relevant functional properties and how this mapping determines the informativeness of neural units for the stimuli and the task to be learned. From this hypothesis we would expect that visual experience would strengthen the pre-learning distributed functional map of the relevant distinctive object properties. Here we present a first test of this prediction in twelve human subjects who were trained in object categorization and differentiation, preceded and followed by a functional magnetic resonance imaging session. Specifically, training increased the distributed multi-voxel pattern information for trained object distinctions in object-selective cortex, resulting in a generalization from pre-training multi-voxel activity patterns to after-training activity patterns. Simulations show that the increased selectivity combined with the inter-session generalization is consistent with a training-induced strengthening of a pre-existing selectivity map. No training-related neural changes were detected in other regions. In sum, training to categorize or individuate objects strengthened pre-existing representations in human object-selective cortex, providing a first indication that the neuroanatomical distribution of learning effects depends upon the pre-learning mapping of visual object properties. Copyright © 2015 Elsevier Inc. All rights reserved.

Cortical Circuit for Binding Object Identity and Location During Multiple-Object Tracking

PubMed Central

Nummenmaa, Lauri; Oksama, Lauri; Glerean, Erico; Hyönä, Jukka

2017-01-01

Abstract Sustained multifocal attention for moving targets requires binding object identities with their locations. The brain mechanisms of identity-location binding during attentive tracking have remained unresolved. In 2 functional magnetic resonance imaging experiments, we measured participants’ hemodynamic activity during attentive tracking of multiple objects with equivalent (multiple-object tracking) versus distinct (multiple identity tracking, MIT) identities. Task load was manipulated parametrically. Both tasks activated large frontoparietal circuits. MIT led to significantly increased activity in frontoparietal and temporal systems subserving object recognition and working memory. These effects were replicated when eye movements were prohibited. MIT was associated with significantly increased functional connectivity between lateral temporal and frontal and parietal regions. We propose that coordinated activity of this network subserves identity-location binding during attentive tracking. PMID:27913430

The internal/external issue what is an outer object? Another person as object and as separate other in object relations models.

PubMed

Zachrisson, Anders

2013-01-01

The question of what we mean by the term outer object has its roots in the epistemological foundation of psychoanalysis. From the very beginning, Freud's view was Kantian, and psychoanalysis has kept that stance, as it seems. The author reviews the internal/external issue in Freud's thinking and in the central object relations theories (Klein, Winnicott, and Bion). On this background he proposes a simple model to differentiate the concept of object along one central dimension: internal object, external object, and actual person. The main arguments are: (1) there is no direct, unmediated perception of the actual person--the experience of the other is always affected by the perceiver's subjectivity; (2) in intense transference reactions and projections, the perception of the person is dominated by the qualities of an inner object--and the other person "becomes" an external object for the perceiver; (3) when this distortion is less dominating, the other person to a higher degree remains a separate other--a person in his or her own right. Clinical material illustrates these phenomena, and a graphical picture of the model is presented. Finally with the model as background, the author comments on a selection of phenomena and concepts such as unobjectionable transference, "the third position," mourning and loneliness. The way that the internal colours and distorts the external is of course a central preoccupation of psychoanalysis generally. (Spillius et al., 2011, p. 326)

Registration of Space Objects

NASA Astrophysics Data System (ADS)

Schmidt-Tedd, Bernhard

2017-07-01

Space objects are subject to registration in order to allocate "jurisdiction and control" over those objects in the sovereign-free environment of outer space. This approach is similar to the registration of ships in view of the high sea and for aircrafts with respect to the international airspace. Registration is one of the basic principles of space law, starting with UN General Assembly Resolution 1721 B (XVI) of December 20, 1961, followed by Resolution 1962 (XVIII) of December 13, 1963, then formulated in Article VIII of the Outer Space Treaty of 1967 and as specified in the Registration Convention of 1975. Registration of space objects can be seen today as a principle of customary international law, relevant for each spacefaring state. Registration is divided into a national and an international level. The State Party establishes a national registry for its space objects, and those registrations have to be communicated via diplomatic channel to the UN Register of space objects. This UN Register is handled by the UN Office for Outer Space Affairs (UNOOSA) and is an open source of information for space objects worldwide. Registration is linked to the so-called launching state of the relevant space object. There might be more than one launching state for the specific launch event, but only one state actor can register a specific space object. The state of registry gains "jurisdiction and control" over the space object and therefore no double registration is permissible. Based on the established UN Space Law, registration practice was subject to some adaptions due to technical developments and legal challenges. After the privatization of the major international satellite organizations, a number of non-registrations had to be faced. The state actors reacted with the UN Registration Practice Resolution of 2007 as elaborated in the Legal Subcommittee of UNCOPUOS, the Committee for the Peaceful Use of Outer Space. In this context an UNOOSA Registration Information

Factors affecting infants' manual search for occluded objects and the genesis of object permanence.

PubMed

Moore, M Keith; Meltzoff, Andrew N

2008-04-01

Two experiments systematically examined factors that influence infants' manual search for hidden objects (N=96). Experiment 1 used a new procedure to assess infants' search for partially versus totally occluded objects. Results showed that 8.75-month-old infants solved partial occlusions by removing the occluder and uncovering the object, but these same infants failed to use this skill on total occlusions. Experiment 2 used sound-producing objects to provide a perceptual clue to the objects' hidden location. Sound clues significantly increased the success rate on total occlusions for 10-month-olds, but not for 8.75-month-olds. An identity development account is offered for why infants succeed on partial occlusions earlier than total occlusions and why sound helps only the older infants. We propose a mechanism for how infants use object identity as a basis for developing a notion of permanence. Implications are drawn for understanding the dissociation between looking time and search assessments of object permanence.

Object strength--an accurate measure for small objects that is insensitive to partial volume effects.

PubMed

Tofts, P S; Silver, N C; Barker, G J; Gass, A

2005-07-01

There are currently four problems in characterising small nonuniform lesions or other objects in Magnetic Resonance images where partial volume effects are significant. Object size is over- or under-estimated; boundaries are often not reproducible; mean object value cannot be measured; and fuzzy borders cannot be accommodated. A new measure, Object Strength, is proposed. This is the sum of all abnormal intensities, above a uniform background value. For a uniform object, this is simply the product of the increase in intensity and the size of the object. Biologically, this could be at least as relevant as existing measures of size or mean intensity. We hypothesise that Object Strength will perform better than traditional area measurements in characterising small objects. In a pilot study, the reproducibility of object strength measurements was investigated using MR images of small multiple sclerosis (MS) lesions. In addition, accuracy was investigated using artificial lesions of known volume (0.3-6.2 ml) and realistic appearance. Reproducibility approached that of area measurements (in 33/90 lesion reports the difference between repeats was less than for area measurements). Total lesion volume was accurate to 0.2%. In conclusion, Object Strength has potential for improved characterisation of small lesions and objects in imaging and possibly spectroscopy.

Accuracy and predictability in use of AO three-dimensionally preformed titanium mesh plates for posttraumatic orbital reconstruction: a pilot study.

PubMed

Scolozzi, Paolo; Momjian, Armen; Heuberger, Joris; Andersen, Elene; Broome, Martin; Terzic, Andrej; Jaques, Bertrand

2009-07-01

The aim of this study was to prospectively evaluate the accuracy and predictability of new three-dimensionally preformed AO titanium mesh plates for posttraumatic orbital wall reconstruction.We analyzed the preoperative and postoperative clinical and radiologic data of 10 patients with isolated blow-out orbital fractures. Fracture locations were as follows: floor (N = 7; 70%), medial wall (N = 1; 1%), and floor/medial wall (N = 2; 2%). The floor fractures were exposed by a standard transconjunctival approach, whereas a combined transcaruncular transconjunctival approach was used in patients with medial wall fractures. A three-dimensional preformed AO titanium mesh plate (0.4 mm in thickness) was selected according to the size of the defect previously measured on the preoperative computed tomographic (CT) scan examination and fixed at the inferior orbital rim with 1 or 2 screws. The accuracy of plate positioning of the reconstructed orbit was assessed on the postoperative CT scan. Coronal CT scan slices were used to measure bony orbital volume using OsiriX Medical Image software. Reconstructed versus uninjured orbital volume were statistically correlated.Nine patients (90%) had a successful treatment outcome without complications. One patient (10%) developed a mechanical limitation of upward gaze with a resulting handicapping diplopia requiring hardware removal. Postoperative orbital CT scan showed an anatomic three-dimensional placement of the orbital mesh plates in all of the patients. Volume data of the reconstructed orbit fitted that of the contralateral uninjured orbit with accuracy to within 2.5 cm(3). There was no significant difference in volume between the reconstructed and uninjured orbits.This preliminary study has demonstrated that three-dimensionally preformed AO titanium mesh plates for posttraumatic orbital wall reconstruction results in (1) a high rate of success with an acceptable rate of major clinical complications (10%) and (2) an anatomic

Intermediate BL Lac objects

NASA Astrophysics Data System (ADS)

Bondi, M.; Marchã, M. J. M.; Dallacasa, D.; Stanghellini, C.

2001-08-01

The 200-mJy sample, defined by Marchã et al., contains about 60 nearby, northern, flat-spectrum radio sources. In particular, the sample has proved effective at finding nearby radio-selected BL Lac objects with radio luminosities comparable to those of X-ray-selected objects, and low-luminosity flat-spectrum weak emission-line radio galaxies (WLRGs). The 200-mJy sample contains 23 BL Lac objects (including 6 BL Lac candidates) and 19 WLRGs. We will refer to these subsamples as the 200-mJy BL Lac sample and the 200-mJy WLRG sample, respectively. We have started a systematic analysis of the morphological pc-scale properties of the 200-mJy radio sources using VLBI observations. This paper presents VLBI observations at 5 and 1.6GHz of 14 BL Lac objects and WLRGs selected from the 200-mJy sample. The pc-scale morphology of these objects is briefly discussed. We derive the radio beaming parameters of the 200-mJy BL Lac objects and WLRGs and compare them with those of other BL Lac samples and with a sample of FR I radio galaxies. The overall broad-band radio, optical and X-ray properties of the 200-mJy BL Lac sample are discussed and compared with those of other BL Lac samples, radio- and X-ray-selected. We find that the 200-mJy BL Lac objects fill the gap between HBL and LBL objects in the colour-colour plot, and have intermediate αXOX as expected in the spectral energy distribution unification scenario. Finally, we briefly discuss the role of the WLRGs.

Seasonal and interannual variability of the Arctic sea ice: A comparison between AO-FVCOM and observations

NASA Astrophysics Data System (ADS)

Zhang, Yu; Chen, Changsheng; Beardsley, Robert C.; Gao, Guoping; Qi, Jianhua; Lin, Huichan

2016-11-01

A high-resolution (up to 2 km), unstructured-grid, fully ice-sea coupled Arctic Ocean Finite-Volume Community Ocean Model (AO-FVCOM) was used to simulate the sea ice in the Arctic over the period 1978-2014. The spatial-varying horizontal model resolution was designed to better resolve both topographic and baroclinic dynamics scales over the Arctic slope and narrow straits. The model-simulated sea ice was in good agreement with available observed sea ice extent, concentration, drift velocity and thickness, not only in seasonal and interannual variability but also in spatial distribution. Compared with six other Arctic Ocean models (ECCO2, GSFC, INMOM, ORCA, NAME, and UW), the AO-FVCOM-simulated ice thickness showed a higher mean correlation coefficient of ˜0.63 and a smaller residual with observations. Model-produced ice drift speed and direction errors varied with wind speed: the speed and direction errors increased and decreased as the wind speed increased, respectively. Efforts were made to examine the influences of parameterizations of air-ice external and ice-water interfacial stresses on the model-produced bias. The ice drift direction was more sensitive to air-ice drag coefficients and turning angles than the ice drift speed. Increasing or decreasing either 10% in water-ice drag coefficient or 10° in water-ice turning angle did not show a significant influence on the ice drift velocity simulation results although the sea ice drift speed was more sensitive to these two parameters than the sea ice drift direction. Using the COARE 4.0-derived parameterization of air-water drag coefficient for wind stress did not significantly influence the ice drift velocity simulation.

Object knowledge modulates colour appearance.

PubMed

Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

2011-01-01

We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis.

Object knowledge modulates colour appearance

PubMed Central

Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

2011-01-01

We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis. PMID:23145224

An Optical/Near-infrared Investigation of HD 100546 b with the Gemini Planet Imager and MagAO

NASA Astrophysics Data System (ADS)

Rameau, Julien; Follette, Katherine B.; Pueyo, Laurent; Marois, Christian; Macintosh, Bruce; Millar-Blanchaer, Maxwell; Wang, Jason J.; Vega, David; Doyon, René; Lafrenière, David; Nielsen, Eric L.; Bailey, Vanessa; Chilcote, Jeffrey K.; Close, Laird M.; Esposito, Thomas M.; Males, Jared R.; Metchev, Stanimir; Morzinski, Katie M.; Ruffio, Jean-Baptiste; Wolff, Schuyler G.; Ammons, S. M.; Barman, Travis S.; Bulger, Joanna; Cotten, Tara; De Rosa, Robert J.; Duchene, Gaspard; Fitzgerald, Michael P.; Goodsell, Stephen; Graham, James R.; Greenbaum, Alexandra Z.; Hibon, Pascale; Hung, Li-Wei; Ingraham, Patrick; Kalas, Paul; Konopacky, Quinn; Larkin, James E.; Maire, Jérôme; Marchis, Franck; Oppenheimer, Rebecca; Palmer, David; Patience, Jennifer; Perrin, Marshall D.; Poyneer, Lisa; Rajan, Abhijith; Rantakyrö, Fredrik T.; Marley, Mark S.; Savransky, Dmitry; Schneider, Adam C.; Sivaramakrishnan, Anand; Song, Inseok; Soummer, Remi; Thomas, Sandrine; Wallace, J. Kent; Ward-Duong, Kimberly; Wiktorowicz, Sloane

2017-06-01

We present H band spectroscopic and Hα photometric observations of HD 100546 obtained with the Gemini Planet Imager and the Magellan Visible AO camera. We detect H band emission at the location of the protoplanet HD 100546 b, but show that the choice of data processing parameters strongly affects the morphology of this source. It appears point-like in some aggressive reductions, but rejoins an extended disk structure in the majority of the others. Furthermore, we demonstrate that this emission appears stationary on a timescale of 4.6 years, inconsistent at the 2σ level with a Keplerian clockwise orbit at 59 au in the disk plane. The H band spectrum of the emission is inconsistent with any type of low effective temperature object or accreting protoplanetary disk. It strongly suggests a scattered-light origin, as this is consistent with the spectrum of the star and the spectra extracted at other locations in the disk. A non-detection at the 5σ level of HD 100546 b in differential Hα imaging places an upper limit, assuming the protoplanet lies in a gap free of extinction, on the accretion luminosity of 1.7 × 10-4 L ⊙ and M\\dot{M}< 6.3× {10}-7 {M}{Jup}2 {{yr}}-1 for 1 R Jup. These limits are comparable to the accretion luminosity and accretion rate of T-Tauri stars or LkCa 15 b. Taken together, these lines of evidence suggest that the H band source at the location of HD 100546 b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the point-spread function subtraction process. This non-detection is consistent with the non-detection in the K band reported in an earlier study but does not exclude the possibility that HD 100546 b is deeply embedded.

Learned Non-Rigid Object Motion is a View-Invariant Cue to Recognizing Novel Objects

PubMed Central

Chuang, Lewis L.; Vuong, Quoc C.; Bülthoff, Heinrich H.

2012-01-01

There is evidence that observers use learned object motion to recognize objects. For instance, studies have shown that reversing the learned direction in which a rigid object rotated in depth impaired recognition accuracy. This motion reversal can be achieved by playing animation sequences of moving objects in reverse frame order. In the current study, we used this sequence-reversal manipulation to investigate whether observers encode the motion of dynamic objects in visual memory, and whether such dynamic representations are encoded in a way that is dependent on the viewing conditions. Participants first learned dynamic novel objects, presented as animation sequences. Following learning, they were then tested on their ability to recognize these learned objects when their animation sequence was shown in the same sequence order as during learning or in the reverse sequence order. In Experiment 1, we found that non-rigid motion contributed to recognition performance; that is, sequence-reversal decreased sensitivity across different tasks. In subsequent experiments, we tested the recognition of non-rigidly deforming (Experiment 2) and rigidly rotating (Experiment 3) objects across novel viewpoints. Recognition performance was affected by viewpoint changes for both experiments. Learned non-rigid motion continued to contribute to recognition performance and this benefit was the same across all viewpoint changes. By comparison, learned rigid motion did not contribute to recognition performance. These results suggest that non-rigid motion provides a source of information for recognizing dynamic objects, which is not affected by changes to viewpoint. PMID:22661939

The AIROPA software package: milestones for testing general relativity in the strong gravity regime with AO

NASA Astrophysics Data System (ADS)

Witzel, Gunther; Lu, Jessica R.; Ghez, Andrea M.; Martinez, Gregory D.; Fitzgerald, Michael P.; Britton, Matthew; Sitarski, Breann N.; Do, Tuan; Campbell, Randall D.; Service, Maxwell; Matthews, Keith; Morris, Mark R.; Becklin, E. E.; Wizinowich, Peter L.; Ragland, Sam; Doppmann, Greg; Neyman, Chris; Lyke, James; Kassis, Marc; Rizzi, Luca; Lilley, Scott; Rampy, Rachel

2016-07-01

General relativity can be tested in the strong gravity regime by monitoring stars orbiting the supermassive black hole at the Galactic Center with adaptive optics. However, the limiting source of uncertainty is the spatial PSF variability due to atmospheric anisoplanatism and instrumental aberrations. The Galactic Center Group at UCLA has completed a project developing algorithms to predict PSF variability for Keck AO images. We have created a new software package (AIROPA), based on modified versions of StarFinder and Arroyo, that takes atmospheric turbulence profiles, instrumental aberration maps, and images as inputs and delivers improved photometry and astrometry on crowded fields. This software package will be made publicly available soon.

A Survey of the High Order Multiplicity of Nearby Solar-Type Binary Stars with Robo-AO

DTIC Science & Technology

2015-01-20

auxiliary images are not used for astrometry or photometry , but are helpful for verifying compan- ion detection and for resolving the 180◦ ambiguity of...pair Ba,Bb was resolved by Robo-AO three times at 0.′′16 with Δi = 0.87m, Δr = 0.97m, and Δz = 0.52m. This corresponds to a mass for Bb of ∼0.6M. We...known quintuple system. The component E (STF 2032AE, E=HIP 79551=GJ 615.2C) is resolved here at 0.′′4 (but not for the first time : Ea,Eb=YSC 152

Robot Grasps Rotating Object

NASA Technical Reports Server (NTRS)

Wilcox, Brian H.; Tso, Kam S.; Litwin, Todd E.; Hayati, Samad A.; Bon, Bruce B.

1991-01-01

Experimental robotic system semiautomatically grasps rotating object, stops rotation, and pulls object to rest in fixture. Based on combination of advanced techniques for sensing and control, constructed to test concepts for robotic recapture of spinning artificial satellites. Potential terrestrial applications for technology developed with help of system includes tracking and grasping of industrial parts on conveyor belts, tracking of vehicles and animals, and soft grasping of moving objects in general.

APPLICATION OF DATA QUALITY OBJECTIVES AND MEASUREMENT QUALITY OBJECTIVES TO RESEARCH PROJECTS

EPA Science Inventory

The paper assists systematic planning for research projects. It presents planning concepts in terms that have some utility for researchers. For example, measurement quality objectives are more familiar to researchers than data quality objectives because these quality criteria are...

Discovery of soft X-ray flux from 2A 1102+384 = Markarian 421

NASA Technical Reports Server (NTRS)

Hearn, D. R.; Marshall, F. J.; Jernigan, J. G.

1979-01-01

During April 1976 a soft X-ray flux was detected with SAS 3 from the vicinity of 2A 1102+384. The average flux densities were 4.3 x 10 to the -11th and 14 x 10 to the -11th erg/sq cm per sec in the energy bands 0.1-0.28 keV and 1-6 keV, respectively. There is an indication of variability over about 0.5 day in the lowest energy band. An upper limit of 3 x 10 to the 20th H atoms per sq cm is found for the gas column density to the X-ray source. In May 1978, observations with the modulation collimators of SAS 3 yielded an accurate (40 arcsec error radius) position for the X-ray source (2-6 keV) at right ascension 11 h 1 m 39.7 s, declination + 38 deg 28 min 51 sec (equinox 1950). The earlier tentative identification by Ricketts et al. (1976) with the BL Lacertae object B2 1101+38 = Markarian 421 is thus confirmed.

Object-oriented productivity metrics

NASA Technical Reports Server (NTRS)

Connell, John L.; Eller, Nancy

1992-01-01

Software productivity metrics are useful for sizing and costing proposed software and for measuring development productivity. Estimating and measuring source lines of code (SLOC) has proven to be a bad idea because it encourages writing more lines of code and using lower level languages. Function Point Analysis is an improved software metric system, but it is not compatible with newer rapid prototyping and object-oriented approaches to software development. A process is presented here for counting object-oriented effort points, based on a preliminary object-oriented analysis. It is proposed that this approach is compatible with object-oriented analysis, design, programming, and rapid prototyping. Statistics gathered on actual projects are presented to validate the approach.

A validated set of tool pictures with matched objects and non-objects for laterality research.

PubMed

Verma, Ark; Brysbaert, Marc

2015-01-01

Neuropsychological and neuroimaging research has established that knowledge related to tool use and tool recognition is lateralized to the left cerebral hemisphere. Recently, behavioural studies with the visual half-field technique have confirmed the lateralization. A limitation of this research was that different sets of stimuli had to be used for the comparison of tools to other objects and objects to non-objects. Therefore, we developed a new set of stimuli containing matched triplets of tools, other objects and non-objects. With the new stimulus set, we successfully replicated the findings of no visual field advantage for objects in an object recognition task combined with a significant right visual field advantage for tools in a tool recognition task. The set of stimuli is available as supplemental data to this article.

Object classification for obstacle avoidance

NASA Astrophysics Data System (ADS)

Regensburger, Uwe; Graefe, Volker

1991-03-01

Object recognition is necessary for any mobile robot operating autonomously in the real world. This paper discusses an object classifier based on a 2-D object model. Obstacle candidates are tracked and analyzed false alarms generated by the object detector are recognized and rejected. The methods have been implemented on a multi-processor system and tested in real-world experiments. They work reliably under favorable conditions but sometimes problems occur e. g. when objects contain many features (edges) or move in front of structured background.

Cognitive object recognition system (CORS)

NASA Astrophysics Data System (ADS)

Raju, Chaitanya; Varadarajan, Karthik Mahesh; Krishnamurthi, Niyant; Xu, Shuli; Biederman, Irving; Kelley, Troy

2010-04-01

We have developed a framework, Cognitive Object Recognition System (CORS), inspired by current neurocomputational models and psychophysical research in which multiple recognition algorithms (shape based geometric primitives, 'geons,' and non-geometric feature-based algorithms) are integrated to provide a comprehensive solution to object recognition and landmarking. Objects are defined as a combination of geons, corresponding to their simple parts, and the relations among the parts. However, those objects that are not easily decomposable into geons, such as bushes and trees, are recognized by CORS using "feature-based" algorithms. The unique interaction between these algorithms is a novel approach that combines the effectiveness of both algorithms and takes us closer to a generalized approach to object recognition. CORS allows recognition of objects through a larger range of poses using geometric primitives and performs well under heavy occlusion - about 35% of object surface is sufficient. Furthermore, geon composition of an object allows image understanding and reasoning even with novel objects. With reliable landmarking capability, the system improves vision-based robot navigation in GPS-denied environments. Feasibility of the CORS system was demonstrated with real stereo images captured from a Pioneer robot. The system can currently identify doors, door handles, staircases, trashcans and other relevant landmarks in the indoor environment.

Does long-term object priming depend on the explicit detection of object identity at encoding?

PubMed Central

Gomes, Carlos A.; Mayes, Andrew

2015-01-01

It is currently unclear whether objects have to be explicitly identified at encoding for reliable behavioral long-term object priming to occur. We conducted two experiments that investigated long-term object and non-object priming using a selective-attention encoding manipulation that reduces explicit object identification. In Experiment 1, participants either counted dots flashed within an object picture (shallow encoding) or engaged in an animacy task (deep encoding) at study, whereas, at test, they performed an object-decision task. Priming, as measured by reaction times (RTs), was observed for both types of encoding, and was of equivalent magnitude. In Experiment 2, non-object priming (faster RTs for studied relative to unstudied non-objects) was also obtained under the same selective-attention encoding manipulation as in Experiment 1, and the magnitude of the priming effect was equivalent between experiments. In contrast, we observed a linear decrement in recognition memory accuracy across conditions (deep encoding of Experiment 1 > shallow encoding Experiment 1 > shallow encoding of Experiment 2), suggesting that priming was not contaminated by explicit memory strategies. We argue that our results are more consistent with the identification/production framework than the perceptual/conceptual distinction, and we conclude that priming of pictures largely ignored at encoding can be subserved by the automatic retrieval of two types of instances: one at the motor level and another at an object-decision level. PMID:25852594

Variation characteristics and influences of climate factors on aridity index and its association with AO and ENSO in northern China from 1961 to 2012

NASA Astrophysics Data System (ADS)

Zhang, Kexin; Qian, Xiaoqing; Liu, Puxing; Xu, Yihong; Cao, Liguo; Hao, Yongpei; Dai, Shengpei

2017-10-01

Analyses of the variation characteristics for aridity index (AI) can further enhance the understanding of climate change and have effect on hydrology and agriculture. In this paper, based on the data of 283 standard meteorological stations, the temporal-spatial variations and the influences of climate factors on AI were investigated and the relationship between AI and two climate indices (the Arctic Oscillation (AO); El Nino-Southern Oscillation (ENSO)) were also assessed in northern China (NC) during the period from 1961 to 2012. The results revealed that the annual mean AI decreased at the rate of -0.031 per decade in the past 52 years and the trend was statistically significant at the 0.01 level. The Mann-Kendall (M-K) test presented that the percentages of stations with positive trends and negative trends for AI were 10 and 81.9 % (22.6 % statistically significant), respectively. Spatially, in the western part of 100° E, the extremely dry area declined and the climate tended to become wet obviously. In the eastern part of 100° E, dry area moved toward the east and the south, which resulted in the enhancement of semiarid area and the shrinkage of subhumid area. The contributions of sunshine duration and precipitation to the decline of AI are more than those of other meteorological variables in NC. Moreover, the average temperature has risen significantly and AI decreased in NC, which indicated the existence of "paradox." Relationship between climate indices (AO and ENSO) and AI demonstrated that the influence of ENSO on AI overweight the AO on AI in NC.

Motor experience influences object knowledge.

PubMed

Chrysikou, Evangelia G; Casasanto, Daniel; Thompson-Schill, Sharon L

2017-03-01

An object's perceived readiness-for-action (e.g., its size, the degree of rotation from its canonical position, the user's viewpoint) can influence semantic knowledge retrieval. Yet, the organization of object knowledge may also be affected by body-specific sensorimotor experiences. Here, we investigated whether people's history of performing motor actions with their hands influences the knowledge they store and retrieve about graspable objects. We compared object representations between healthy right- and left-handers (Experiment 1), and between unilateral stroke patients, whose motor experience was changed by impairment of either their right or left hand (Experiment 2). Participants saw pictures of graspable everyday items with the handles oriented toward either the left or right hand, and they generated the type of grasp they would employ (i.e., clench or pinch) when using each object, responding orally. In both experiments, hand dominance and object orientation interacted to predict response times. In Experiment 1, judgments were fastest when objects were oriented toward the right hand in right-handers, but not in left-handers. In Experiment 2, judgments were fastest when objects were oriented toward the left hand in patients who had lost the use of their right hand, even though these patients were right-handed prior to brain injury. Results suggest that at least some aspects of object knowledge are determined by motor experience, and can be changed by new patterns of motor experience. People with different bodily characteristics, who interact with objects in systematically different ways, form correspondingly different neurocognitive representations of the same common objects. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

General object-oriented software development

NASA Technical Reports Server (NTRS)

Seidewitz, Edwin V.; Stark, Mike

1986-01-01

Object-oriented design techniques are gaining increasing popularity for use with the Ada programming language. A general approach to object-oriented design which synthesizes the principles of previous object-oriented methods into the overall software life-cycle, providing transitions from specification to design and from design to code. It therefore provides the basis for a general object-oriented development methodology.

Distributed Object Oriented Programming

DTIC Science & Technology

1990-02-01

of the object oriented model of computation. Therefore, object oriented programming can provide the programmer with good conceptual tools to divide his...LABOR SALES-COMMISSION). The symbol + refers to the addition function and takes any number of numeric arguments. The third subtype of list forms is the...2) ’(:SEND-DONE) (SEWF (AREF OBJECT-i1-MESSAGES-SENT 2) ’(PROGN (FORMAT T "-s methd completely executed instr-ptr -s-V NAME %INSTR-PTR%) (INCF

Factors Affecting Infants’ Manual Search for Occluded Objects and the Genesis of Object Permanence

PubMed Central

Moore, M. Keith; Meltzoff, Andrew N.

2009-01-01

Two experiments systematically examined factors that influence infants’ manual search for hidden objects (N = 96). Experiment 1 used a new procedure to assess infants’ search for partially versus totally occluded objects. Results showed that 8.75-month-old infants solved partial occlusions by removing the occluder and uncovering the object, but these same infants failed to use this skill on total occlusions. Experiment 2 used sound-producing objects to provide a perceptual clue to the objects’ hidden location. Sound clues significantly increased the success rate on total occlusions for 10-month-olds, but not for 8.75-month-olds. An identity development account is offered for why infants succeed on partial occlusions earlier than total occlusions and why sound helps only the older infants. We propose a mechanism for how infants use object identity as a basis for developing a notion of permanence. Implications are drawn for understanding the dissociation between looking-time and search assessments of object permanence. PMID:18036668

Postural and Object-Oriented Experiences Advance Early Reaching, Object Exploration, and Means-End Behavior

ERIC Educational Resources Information Center

Lobo, Michele A.; Galloway, James C.

2008-01-01

The effects of 3 weeks of social (control), postural, or object-oriented experiences on 9- to 21-week-old infants' (N = 42) reaching, exploration, and means-end behaviors were assessed. Coders recorded object contacts, mouthing, fingering, attention, and affect from video. Postural and object-oriented experiences advanced reaching, haptic…

Motor Experience Influences Object Knowledge

PubMed Central

Chrysikou, Evangelia G.; Casasanto, Daniel; Thompson-Schill, Sharon L.

2016-01-01

An object’s perceived readiness-for-action (e.g., its size, the degree of rotation from its canonical position, or the user’s viewpoint) can influence semantic knowledge retrieval. Yet, the organization of object knowledge may also be affected by body-specific sensorimotor experiences. Here, we investigated whether people’s history of performing motor actions with their hands influences the knowledge they store and retrieve about graspable objects. We compared object representations between healthy right- and left-handers (Experiment 1), and between unilateral stroke patients, whose motor experience was changed by impairment of either their right or left hand (Experiment 2). Participants saw pictures of graspable everyday items with the handles oriented toward either the left or right hand, and they generated the type of grasp they would employ (i.e., clench or pinch) when using each object, responding orally. In both experiments, hand dominance and object orientation interacted to predict response times. In Experiment 1, judgments were fastest when objects were oriented toward the right hand in right-handers, but not in left-handers. In Experiment 2, judgments were fastest when objects were oriented toward the left hand in patients who had lost the use of their right hand, even though these patients were right-handed prior to brain injury. Results suggest that at least some aspects of object knowledge are determined by motor experience, and can be changed by new patterns of motor experience. People with different bodily characteristics, who interact with objects in systematically different ways, form correspondingly different neurocognitive representations of the same common objects. PMID:28253009

[Health assessment of Qi'ao Island mangrove wetland ecosystem in Pearl River Estuary].

PubMed

Wang, Shu-Gong; Zheng, Yao-Hui; Peng, Yi-Sheng; Chen, Gui-Zhu

2010-02-01

Based on the theories of wetland ecosystem health and by using "Pressure-State-Response" model, a health assessment indicator system for Qi' ao Island mangrove wetland ecosystem in Pearl River Estuary was built, and the assessment indices, assessment criteria, indices weighted values, assessment grades, and assessment methods were established to assess the health state of this ecosystem. In 2008, the overall health index of this ecosystem was 0.6580, health level was of grade II (healthy), and the pressure, state, and response indices were 0.3469, 0.8718, and 0.7754, respectively, suggesting that this ecosystem was good in state and response, but still had definite pressure. As a provincial nature reserve, this ecosystem was to be further improved in its health level. However, the research on the health assessment of mangrove wetland ecosystem was still young. Further studies should be made on the selection of assessment indices, long-term oriented monitoring of these indices, and quantification of the relations between ecosystem health level and ecosystem services.

Long-term functional outcome of mandibular reconstruction with stainless steel AO reconstruction plates.

PubMed

van Minnen, B; Nauta, J M; Vermey, A; Bos, R R M; Roodenburg, J L N

2002-04-01

Mandibular continuity defects are usually reconstructed with bone grafts. However, factors associated with the tumour and the patient can still be reasons to choose reconstruction plates. The aim of this study was to find out the results of mandibular reconstructions with stainless steel AO reconstruction plates after a long follow-up period. The records of 36 patients were reviewed for personal data and the history of disease, treatment and complications. Patients with failed reconstructions were compared with those in whom the procedure had been successful. Patients and surgeons gave their opinion on the functional and cosmetic results. The mean follow-up was 39 months (range 4-99); 4 patients were withdrawn because they developed early recurrent disease and in 17 patients the reconstruction failed. We found no significant differences between the successful and the failed group. Fourteen patients could be evaluated for functional outcome, 10 of whom were totally or satisfactorily rehabilitated. Therefore, stainless steel reconstruction plates can be used in patients when other options are inappropriate.

Multiple-object permanence tracking: limitation in maintenance and transformation of perceptual objects.

PubMed

Saiki, Jun

2002-01-01

Research on change blindness and transsaccadic memory revealed that a limited amount of information is retained across visual disruptions in visual working memory. It has been proposed that visual working memory can hold four to five coherent object representations. To investigate their maintenance and transformation in dynamic situations, I devised an experimental paradigm called multiple-object permanence tracking (MOPT) that measures memory for multiple feature-location bindings in dynamic situations. Observers were asked to detect any color switch in the middle of a regular rotation of a pattern with multiple colored disks behind an occluder. The color-switch detection performance dramatically declined as the pattern rotation velocity increased, and this effect of object motion was independent of the number of targets. The MOPT task with various shapes and colors showed that color-shape conjunctions are not available in the MOPT task. These results suggest that even completely predictable motion severely reduces our capacity of object representations, from four to only one or two.

Membrane biofouling process correlated to the microbial community succession in an A/O MBR.

PubMed

Chen, Chun-Hong; Fu, Yuan; Gao, Da-Wen

2015-12-01

The microbial community succession of the biofouling layer in a submerged anoxic/oxic membrane biological reactor (A/O MBR) that fed with synthesized domestic wastewater was investigated under three different flux conditions without the changing of the nutrient load. The noticeable microbial community succession and its significant correlation with the metabolic products were observed under the subcritical flux condition. Under the supercritical flux condition, the microbial community shift was in a different pattern compared with that under the subcritical flux condition and it was affected by the increased permeable suction more than the metabolic products. The most abundant microorganisms in the foulants were β-proteobacteria and γ-proteobacteria which can reach more than 20% of the microbial community. However the microorganisms which had significant correlation with the metabolic products were in lower abundance. Copyright © 2015 Elsevier Ltd. All rights reserved.

SODA: Smart Objects, Dumb Archives

NASA Technical Reports Server (NTRS)

Nelson, Michael L.; Maly, Kurt; Zubair, Mohammad; Shen, Stewart N. T.

2004-01-01

We present the Smart Object, Dumb Archive (SODA) model for digital libraries (DLs). The SODA model transfers functionality traditionally associated with archives to the archived objects themselves. We are exploiting this shift of responsibility to facilitate other DL goals, such as interoperability, object intelligence and mobility, and heterogeneity. Objects in a SODA DL negotiate presentation of content and handle their own terms and conditions. In this paper we present implementations of our smart objects, buckets, and our dumb archive (DA). We discuss the status of buckets and DA and how they are used in a variety of DL projects.

Magellan adaptive optics first-light observations of the exoplanet β PIC b. I. Direct imaging in the far-red optical with MagAO+VisAO and in the near-IR with NICI {sup ,}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Males, Jared R.; Close, Laird M.; Morzinski, Katie M.

We present the first ground-based CCD (λ < 1 μm) image of an extrasolar planet. Using the Magellan Adaptive Optics system's VisAO camera, we detected the extrasolar giant planet β Pictoris b in Y-short (Y{sub S} , 0.985 μm), at a separation of 0.470 ± 0.''010 and a contrast of (1.63 ± 0.49) × 10{sup –5}. This detection has a signal-to-noise ratio of 4.1 with an empirically estimated upper limit on false alarm probability of 1.0%. We also present new photometry from the Gemini Near-Infrared Coronagraphic Imager instrument on the Gemini South telescope, in CH {sub 4S,1%} (1.58 μm), K{submore » S} (2.18 μm), and K {sub cont} (2.27 μm). A thorough analysis of our photometry combined with previous measurements yields an estimated near-IR spectral type of L2.5 ± 1.5, consistent with previous estimates. We estimate log (L {sub bol}/L {sub ☉}) = –3.86 ± 0.04, which is consistent with prior estimates for β Pic b and with field early-L brown dwarfs (BDs). This yields a hot-start mass estimate of 11.9 ± 0.7 M {sub Jup} for an age of 21 ± 4 Myr, with an upper limit below the deuterium burning mass. Our L {sub bol}-based hot-start estimate for temperature is T {sub eff} = 1643 ± 32 K (not including model-dependent uncertainty). Due to the large corresponding model-derived radius of R = 1.43 ± 0.02 R {sub Jup}, this T {sub eff} is ∼250 K cooler than would be expected for a field L2.5 BD. Other young, low-gravity (large-radius), ultracool dwarfs and directly imaged EGPs also have lower effective temperatures than are implied by their spectral types. However, such objects tend to be anomalously red in the near-IR compared to field BDs. In contrast, β Pic b has near-IR colors more typical of an early-L dwarf despite its lower inferred temperature.« less

Blind Bayesian restoration of adaptive optics telescope images using generalized Gaussian Markov random field models

NASA Astrophysics Data System (ADS)

Jeffs, Brian D.; Christou, Julian C.

1998-09-01

This paper addresses post processing for resolution enhancement of sequences of short exposure adaptive optics (AO) images of space objects. The unknown residual blur is removed using Bayesian maximum a posteriori blind image restoration techniques. In the problem formulation, both the true image and the unknown blur psf's are represented by the flexible generalized Gaussian Markov random field (GGMRF) model. The GGMRF probability density function provides a natural mechanism for expressing available prior information about the image and blur. Incorporating such prior knowledge in the deconvolution optimization is crucial for the success of blind restoration algorithms. For example, space objects often contain sharp edge boundaries and geometric structures, while the residual blur psf in the corresponding partially corrected AO image is spectrally band limited, and exhibits while the residual blur psf in the corresponding partially corrected AO image is spectrally band limited, and exhibits smoothed, random , texture-like features on a peaked central core. By properly choosing parameters, GGMRF models can accurately represent both the blur psf and the object, and serve to regularize the deconvolution problem. These two GGMRF models also serve as discriminator functions to separate blur and object in the solution. Algorithm performance is demonstrated with examples from synthetic AO images. Results indicate significant resolution enhancement when applied to partially corrected AO images. An efficient computational algorithm is described.

Compilação de dados atômicos e moleculares do UV ao IV próximo para uso em síntese espectral

NASA Astrophysics Data System (ADS)

Coelho, P.; Barbuy, B.; Melendez, J.; Allen, D. M.; Castilho, B.

2003-08-01

Espectros sintéticos são utéis em uma grande variedade de aplicações, desde análise de abundâncias em espectros estelares de alta resolução ao estudo de populações estelares em espectros integrados. A confiabilidade de um espectro sintético depende do modelo de atmosfera adotado, do código de formação de linhas e da qualidade dos dados atômicos e moleculares que são determinantes no cálculo das opacidades da fotosfera. O nosso grupo no departamento de Astronomia no IAG tem utilizado espectros sintéticos há mais de 15 anos, em aplicações voltadas principalmente para a análise de abundâncias de estrelas G, K e M e populações estelares velhas. Ao longo desse tempo, as listas de linhas vieram sendo construídas e atualizadas continuamente, e alguns acréscimos recentes podem ser citados: Castilho (1999, átomos e moléculas no UV), Schiavon (1998, bandas moleculares de TiO) e Melendez (2001, átomos e moléculas no IV próximo). Com o intuito de calcular uma grade de espectros do UV ao IV próximo para uso no estudo de populações estelares velhas, se fazia necessário compilar e homogeneizar as diversas listas em apenas uma lista atômica e uma molecular. Nesse processo, a nova lista compilada foi correlacionada com outras bases de dados (NIST, Kurucz Database, O' Brian et al. 1991) para atualização dos parâmetros que caracterizam a transição atômica (comprimento de onda, log gf e potencial de excitação). Adicionalmente as constantes de interação C6 foram calculadas segundo a teoria de Anstee & O'Mara (1995) e artigos posteriores. As bandas moleculares de CH e CN foram recalculadas com o programa LIFBASE (Luque & Crosley 1999). Nesse poster estão detalhados os procedimentos citados acima, as comparações entre espectros calculados com as novas listas e espectros observados em alta resolução do Sol e de Arcturus, e uma análise do impacto decorrente da utilização de diferentes modelos de atmosfera no espectro sintético. Ao

A Diffraction-limited Survey for Direct Detection of Halpha Emitting/Accreting ExtraSolar Planets with the 6.5m Magellan Telescope and the MagAO Visible AO system

NASA Astrophysics Data System (ADS)

Close, Laird

TECHNICAL BACKGROUND: An advanced adaptive secondary mirror (ASM) with 585 actuators was commissioned at the 6.5-m Magellan Telescope at one of the world’s best sites (Las Campanas Observatory; LCO) in Chile. By the end of the commissioning run (April 2013) the MagAO system was regularly producing the highest spatial resolution deep images to date (0.023” deep images at Halpha (0.656 microns); Close et al. 2013). This is due to its 378 corrective modes at 1kHz on a 6.5-m telescope. Strehl ratis>20% at Halpha were obtained in 75% of the seeing statistics at the site. We propose here to utilize MagAO’s absolutely unique ability to take Halpha, continuum (0.643 microns), and L’ (3.8 microns) thermal images (all simultaneously) to carry out a novel survey to: Discover a population of the lowest mass young accreting extrasolar planets imaged to date. to characterize the spatial distribution, and estimate accretion rates, of young extrasolar planets >5AU, to understand the influence of planets on transitional disk gaps. THEORY BACKGROUND: Extrasolar planets are very difficult to image directly since planets become very faint below ~8 Mjup (Jupiter masses) for ages >1 Myr and such massive planets are rare. There is a class of young stars that are still accreting yet have SED (and often imaging) evidence of a lack of dust and gas inside a r=5-140 AU “gap”. These “transitional disks” are believed to be transitioning into “disk free” stars. These gaps are believed to be maintained by planets that continuously clear (though scattering or accretion) the optically thin gaps. Indeed large >10 AU gaps (>few Hill spheres) must be maintained by multiple ~1 Mjup planets (Dodson-Robinson & Salyk 2011). Since gas must pass through each of these gaps to continuously supply the accreting star, simulations suggest that these “gap planets” are also crossing points for these gas streamers on their way to the star. These streamers “force-feed” these planets a

Semantic memory in object use.

PubMed

Silveri, Maria Caterina; Ciccarelli, Nicoletta