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Sample records for bl lacertae object

  1. BL Lacertae objects

    International Nuclear Information System (INIS)

    The properties of BL Lacertae objects are discussed including their spectra, variability, and brightness. The historical development of observation, and the conclusion that these objects are possibly quasar-related objects rather than variable stars as originally supposed are treated. The possible mechanisms for the unusual luminosity of these objects are considered

  2. Polarization and Variations of BL Lacertae Objects

    OpenAIRE

    Fan, J.H.; Cheng, K. S.; Zhang, L.

    1999-01-01

    BL Lacertae objects are an extreme subclass of AGNs showing rapid and large-amplitude variability, high and variable polarization, and core-dominated radio emissions. If a strong beaming effect is the cause of the extreme observation properties, one would expect that these properties would be correlated with each other. Based on the relativistic beaming model, relationships between the polarization and the magnitude variation in brightness, as well as the core- dominance parameter are derived...

  3. The milliarcsecond polarization structure of six BL Lacertae objects

    International Nuclear Information System (INIS)

    Milliarcsecond resolution total intensity and linear polarization maps at GHz are presented for the BL Lacertae objects 0235 + 164, 0454 + 844, 1749 + 096, 1823 + 568, and 2200 + 420 (BL Lac). Maps of 1807 + 698 (3C 371), which has in the past been classified either as a BL Lacertae object or an N galaxy, are also presented. Appreciable polarization structure is found in 0454 + 844, 1823 + 568, and BL Lac; in each the polarization position angle in the knots lies within about 10 deg of the structural direction of the VLBI jet, suggesting that plane perpendicular shock waves may be common in these objects. The polarization of 3C 371 is weak, and is quite atypical of BL Lacertae objects. Superluminal motion in 1823 + 568 is suggested. Similar comparison for 0454 + 844 over four epochs confirms proper motion at mu about 0.14 mas/yr. Systematic differences in the VLBI polarization structures of BL Lacertae objects and quasars rule out the possibility that a significant fraction of BL Lacertae objects are gravitationally microlensed quasars. 87 refs

  4. Infrared Variation of Radio Selected BL Lacertae Objects

    OpenAIRE

    Fan, J. H.; Lin, R. G.

    1999-01-01

    In this paper, the historical infrared (JHK) data compiled from the published literature are presented in electronic form for 40 radio selected BL Lacertae objects (RBLs) for the first time. Largest variations are found and compared with the largest optical variation. Relations between color index and magnitude and between color-color indices are discussed individually. For the color-magnitude relation, some objects (0048-097, 0735+178, 0851+202, 1215+303, 1219+285, 1749+096, and perhaps 0219...

  5. BeppoSAX observations of 1 Jy BL Lacertae objects

    International Nuclear Information System (INIS)

    Preliminary results on BeppoSAX LECS and MECS observations of BL Lacertae objects selected from the 1 Jy sample are presented. All sources of the LBL type, that is, characterized by a peak in their multifrequency spectra at infrared/optical energies, seem to show a relatively flat (αx ∼ 0.7 - 0.8) X-ray spectrum. This is in agreement with the supposed dominance of inverse Compton emission in the X-ray band of these sources

  6. X-ray spectroscopy of five BL Lacertae objects

    Science.gov (United States)

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

    1986-01-01

    Five X-ray bright BL Lacertae objects were observed in the energy range 0.6-4.5 keV with the solid state spectrometer (SSS) of the Einstein Observatory. The 14 SSS spectra obtained represent most of the X-ray spectra of BL Lac objects with resolution better than approximately 3. These data do not reveal the presence of large amounts of thermal gas, with upper limits for the equivalent width of individual spectral features typically less that about 100 eV. However, the SSS spectra are the first set of X-ray data to indicate low-energy absorption in excess of that caused by the cold interstellar matter in the Galaxy. Comparison with contemporaneous, lower energy X-ray data implies that this absorption does not arise in cold neutral material, but in hotter, highly ionized material, probably intrinsic to the source. All five BL Lac objects have X-ray continua that are well fitted by power-law models, with power-law energy indices usually greater than about 1. In a few cases, a flattening at higher energies is observed; these and other data suggest that two-component X-ray spectra, steep at low energies and flat at high energies, are a common feature of BL Lac objects. Three of the five sources clearly vary between SSS observations, with time scales ranging from days to years. A historical synopsis of the X-ray spectral data confirms the tendency for BL Lacertae objects to be highly variable in the X-ray band but reveals no correlation between spectral and intensity changes.

  7. Relativistic Beaming and Orientation Effects in BL Lacertae Objects

    Indian Academy of Sciences (India)

    F. C. Odo; A. A. Ubachukwu; A. E. Chukwude

    2012-09-01

    We use the correlation between the core-to-lobe radio luminosity ratio () and the linear size () of a sample of BL Lacertae objects to investigate the relativistic beaming and radio source orientation paradigm for high peaked and low-peaked BL Lacs (X-ray and radio selected BL Lacs respectively) and to constrain relativistic beaming model for this extreme class of active galactic nuclei. We show that the - distributions of the BL Lac populations contradict blazar orientation sequence, with the X-ray selected BL Lacs (XBLs) being more consistent with the beaming and orientation model. On the premise that Fanaroff-Riley Type I radio galaxies are the unbeamed parent population of these objects, we derive the bulk Lorentz factor of the jets, ∼ 7-20 corresponding to a critical cone angle for optimum boosting, c of ∼ 1° - 4°, while on average, these objects are inclined at 5° - 12° to the line-of-sight. The implications of these results for the blazar unification sequence are discussed.

  8. On the relationship between BL Lacertae objects and radio galaxies

    CERN Document Server

    Landt, Hermine

    2008-01-01

    We present deep radio images at 1.4 GHz of a large and complete sample of BL Lacertae objects (BL Lacs) selected from the Deep X-ray Radio Blazar Survey (DXRBS). We have observed 24 northern sources with the Very Large Array (VLA) in both its A and C configurations and 15 southern sources with the Australia Telescope Compact Array (ATCA) in its largest configuration. We find that in the DXRBS, as in the 1-Jy survey, which has a radio flux limit roughly ten times higher than the DXRBS, a considerable number (about a third) of BL Lacs can be identified with the relativistically beamed counterparts of Fanaroff-Riley type II (FR II) radio galaxies. We attribute the existence of FR II-BL Lacs, which is not accounted for by current unified schemes, to an inconsistency in our classification scheme for radio-loud active galactic nuclei (AGN). Taking the extended radio power as a suitable measure of intrinsic jet power, we find similar average values for low- (LBL) and high-energy peaked BL Lacs (HBL), contrary to the...

  9. Intranight optical variability of radio-quiet BL Lacertae objects

    CERN Document Server

    Liu, Yuan; Zhang, Shuang Nan

    2015-01-01

    Aims: The intranight variation (or microvariation) is a common phenomenon of radio-loud BL Lac objects. However, it is not clear whether the recently found radio-quiet BL Lac objects have the same properties. The occurrence rate of intranight variation is helpful in distinguishing the mechanism of the continuum of radio-quiet BL Lac objects. Methods: We conducted a photometric monitoring of 8 radio-quiet BL Lac objects by Xinglong 2.16m and Lijiang 2.4m telescopes. The differential light curves are calculated between each target and two comparison stars. To qualify the variation, the significance of variation is examined by scaled $F$-test. Results: No significant variation is found in the 11 sessions of light curves of 8 radio-quiet BL Lac objects (one galactic source is excluded). The lack of microvariation in radio-quiet BL Lac objects is consistent with the detection rate of microvariation in normal radio-quiet AGNs, but much lower than that of radio-loud AGNs. This result indicates that the continua of t...

  10. Is BZB J1450+5201 the most distant $\\gamma$-ray BL Lacertae object?

    OpenAIRE

    Liao, N. H.; Bai, J. M.; Wang, J. G.; Liu, H.T.; Zhang, J. J.; Jiang, Ning; Yuan, Z. L.; Chen, Liang

    2013-01-01

    BL Lacertae (BL Lac) objects at high redshifts ($z\\geq 2$) are rarely detected. Through careful analysis of the SDSS spectrum, BZB J1450+5201 is confirmed to be a high-$z$ BL Lac object with $z\\geq$ 2.471 by identifying the Ly$\\alpha$ 1216 and CIV 1548/1550 absorption lines. This indicates that BZB J1450+5201 is the most distant BL Lac object discovered to date. Careful analysis of the five-year \\fermi data of 2FGL J1451.0+5159 shows that its $\\gamma$-ray emission is robust with confidence le...

  11. The Connection between X-ray- and Radio-Selected BL Lacertae Objects

    OpenAIRE

    Padovani, Paolo; Giommi, Paolo

    1994-01-01

    We explain the properties of X-ray selected BL Lacertae objects, under the assumption that they constitute the small minority of the BL Lac population with energy cutoff located in the UV/X-ray band, as suggested by their multifrequency spectra. In particular, we derive their X-ray luminosity function, log N-log S, and radio flux distribution starting from radio selected BL Lacs using a method that does not require any free parameters. Our hypothesis is at variance with the most common explan...

  12. Possible links between BL Lacertae objects and quasars from very long baseline interferometry radio data.

    Science.gov (United States)

    Gabuzda, D C

    1995-01-01

    Systematic differences in the very long baseline interferometry (VLBI) radio polarization structure and average VLBI component speeds of BL Lacertae objects and quasars support the view that the observational distinction between these classes, based in large part on the strength of their optical line emission, is meaningful; in other words, this distinction reflects significant differences in the physical conditions in these sources. Possible models providing a link between the optical and VLBI properties of BL Lacertae objects and quasars are discussed. Most VLBI polarization observations to date have been global observations made at 6 cm; recent results suggest that the VLBI polarization structure of some sources may change dramatically on scales smaller than those probed by these 6-cm observations. PMID:11607606

  13. Long-Term Optical Spectra Variability of BL Lacertae Object S5 0716+714

    Indian Academy of Sciences (India)

    Zhang Hao Jing; Zhao Gang; Zhang Xiong; Bai Jing Ming; Tang Ling; Xu Yun Bing

    2011-03-01

    Based on the long-term data from observations, we present an evidence for its spectral index variability behaviour in optical bands for BL Lacertae object S5 0716+714.We find that the spectral index variability period is in agreement with the flux variability period of about 1180 days in optical bands.We also find that the spectral index variability has periods of about 71 and 60 days which cannot be compared with the amplitude of long-term variability.

  14. Upper limits from hard X-ray observations of five BL Lacertae objects

    Science.gov (United States)

    Bezler, M.; Gruber, D. E.; Rothschild, R. E.

    1988-01-01

    Results are presented from hard X-ray observations of the five brightest X-ray BL Lacertae objects: PKS 0548-322, Mrk 421 (=1101+384), 2A 1219+305, Mrk 501 (=1652+398), and PKS 2155-304. The observations covered the energy range 15-165 keV from August 1977 to December 1978. The results are compared with previous studies.

  15. QUANTITATIVE EVALUATION OF THE HYPOTHESIS THAT BL LACERTAE OBJECTS ARE QSO REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Borra, E. F. [Centre d' Optique, Photonique et Lasers, Département de Physique, Université Laval, Quebec (Canada)

    2014-11-20

    We evaluate with numerical simulations the hypothesis that BL Lacertae objects (BLLs) are the remnants of quasi-stellar objects. This hypothesis is based on their highly peculiar redshift evolution. They have a comoving space density that increases with decreasing redshift, contrary to all other active galactic nuclei. We assume that relativistic jets are below detection in young radio-quiet quasars and increase in strength with cosmic time so that they eventually are detected as BLLs. Our numerical simulations fit very well the observed redshift distributions of BLLs. There are strong indications that only the high-synchrotron-peaked BLLs could be QSO remnants.

  16. Host galaxy subtraction of TeV candidate BL Lacertae objects

    OpenAIRE

    Nilsson, K.; Pasanen, M.; Takalo, L. O.; Lindfors, E.; Berdyugin, A.; Ciprini, S.; Pforr, J.

    2007-01-01

    We have derived R-band host galaxy fluxes of 20 TeV candidate BL Lacertae objects as a function of aperture radius and FWHM. The results are given as correction tables, that list the fluxes (in mJy) of all ``contaminating'' sources (host galaxy + significant nearby objects) as a function of aperture radius and FWHM. We found that the derived fluxes depend strongly on aperture radius, but the FWHM has only a minor effect (a few percent). We also discuss the implications of our findings to opti...

  17. Search for Cross-Correlations of Ultra--High-Energy Cosmic Rays with BL Lacertae Objects

    CERN Document Server

    Abbasi, R U; Amman, J F; Archbold, G; Atkins, R; Bellido, J A; Belov, K; Belz, J W; Ben-Zvi, S Y; Bergman, D R; Burt, G W; Cao, Z; Clay, R W; Connolly, B C; Deng, W; Dawson, B R; Fedorova, Y; Findlay, J; Finley, C B; Hanlon, W F; Hoffman, C M; Hughes, G A; Holzscheiter, M H; Hüntemeyer, P; Jui, C C H; Kim, K; Kirn, M A; Loh, E C; Maestas, M M; Manago, N; Marek, L J; Martens, K; Matthews, J A J; Matthews, J N; O'Neill, A; Painter, C A; Perera, L P; Reil, K; Riehle, R; Roberts, M; Sasaki, M; Schnetzer, S R; Simpson, K M; Sinnis, G; Smith, J D; Snow, R; Sokolsky, P; Song, C; Springer, R W; Stokes, B T; Thomas, J R; Thomas, S B; Thomson, G B; Tupa, D; Westerhoff, S; Wiencke, L R; Zech, A

    2005-01-01

    Data taken in stereo mode by the High Resolution Fly's Eye (HiRes) air fluorescence experiment are analyzed to search for correlations between the arrival directions of ultra--high-energy cosmic rays with the positions of BL Lacertae objects. Several previous claims of significant correlations between BL Lacs and cosmic rays observed by other experiments are tested. These claims are not supported by the HiRes data. However, we verify a recent analysis of correlations between HiRes events and a subset of confirmed BL Lacs from the 10th Veron Catalog, and we study this correlation in detail. Due to the a posteriori nature of the search, the significance level cannot be reliably estimated and the correlation must be tested independently before any claim can be made. We identify the precise hypotheses that will be tested with statistically independent data.

  18. VERITAS and Multiwavelength Observations of the BL Lacertae Object 1ES 1741+196

    Science.gov (United States)

    Abeysekara, A. U.; Archambault, S.; Archer, A.; Benbow, W.; Bird, R.; Biteau, J.; Buchovecky, M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cardenzana, J. V.; Cerruti, M.; Chen, X.; Christiansen, J. L.; Ciupik, L.; Connolly, M. P.; Cui, W.; Dickinson, H. J.; Dumm, J.; Eisch, J. D.; Errando, M.; Falcone, A.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Flinders, A.; Fortin, P.; Fortson, L.; Furniss, A.; Gillanders, G. H.; Griffin, S.; Grube, J.; Gyuk, G.; Huetten, M.; Hanna, D.; Holder, J.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kelley-Hoskins, N.; Kertzman, M.; Kieda, D.; Krause, M.; Krennrich, F.; Lang, M. J.; Maier, G.; McArthur, S.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nieto, D.; O'Brien, S.; de Bhróithe, A. O'Faoláin; Ong, R. A.; Otte, A. N.; Park, N.; Pelassa, V.; Petrashyk, A.; Petry, D.; Pohl, M.; Popkow, A.; Pueschel, E.; Quinn, J.; Ragan, K.; Ratliff, G.; Reyes, L. C.; Reynolds, P. T.; Reynolds, K.; Richards, G. T.; Roache, E.; Rulten, C.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Tucci, J. V.; Tyler, J.; Vincent, S.; Wakely, S. P.; Weiner, O. M.; Weinstein, A.; Wilhelm, A.; Williams, D. A.; Zitzer, B.

    2016-04-01

    We present results from multiwavelength observations of the BL Lacertae object 1ES 1741+196, including results in the very-high-energy γ-ray regime using the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The VERITAS time-averaged spectrum, measured above 180 GeV, is well-modelled by a power law with a spectral index of 2.7 ± 0.7stat ± 0.2syst. The integral flux above 180 GeV is (3.9 ± 0.8stat ± 1.0syst) × 10-8 m-2 s-1, corresponding to 1.6% of the Crab Nebula flux on average. The multiwavelength spectral energy distribution of the source suggests that 1ES 1741+196 is an extreme-high-frequency-peaked BL Lacertae object. The observations analysed in this paper extend over a period of six years, during which time no strong flares were observed in any band. This analysis is therefore one of the few characterizations of a blazar in a non-flaring state.

  19. VERITAS and Multiwavelength Observations of the BL Lacertae Object 1ES 1741+196

    CERN Document Server

    Abeysekara, A U; Archer, A; Benbow, W; Bird, R; Biteau, J; Buchovecky, M; Buckley, J H; Bugaev, V; Byrum, K; Cardenzana, J V; Cerruti, M; Chen, X; Christiansen, J L; Ciupik, L; Connolly, M P; Cui, W; Dickinson, H J; Dumm, J; Eisch, J D; Errando, M; Falcone, A; Feng, Q; Finley, J P; Fleischhack, H; Flinders, A; Fortin, P; Fortson, L; Furniss, A; Gillanders, G H; Griffin, S; Grube, J; Gyuk, G; Hütten, M; Hanna, D; Holder, J; Humensky, T B; Johnson, C A; Kaaret, P; Kar, P; Kelley-Hoskins, N; Kertzman, M; Kieda, D; Krause, M; Krennrich, F; Kumar, S; Lang, M J; Maier, G; McArthur, S; McCann, A; Meagher, K; Moriarty, P; Mukherjee, R; Nieto, D; O'Brien, S; de Bhróithe, A O'Faoláin; Ong, R A; Otte, A N; Park, N; Pelassa, V; Petrashyk, A; Pohl, M; Popkow, A; Pueschel, E; Quinn, J; Ragan, K; Ratliff, G; Reyes, L C; Reynolds, P T; Richards, G T; Roache, E; Rulten, C; Santander, M; Sembroski, G H; Shahinyan, K; Smith, A W; Staszak, D; Telezhinsky, I; Tucci, J V; Tyler, J; Vincent, S; Wakely, S P; Weiner, O M; Weinstein, A; Wilhelm, A; Williams, D A; Zitzer, B

    2016-01-01

    We present results from multiwavelength observations of the BL Lacertae object 1ES 1741+196, including results in the very-high-energy $\\gamma$-ray regime using the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The VERITAS time-averaged spectrum, measured above 180 GeV, is well-modelled by a power law with a spectral index of $2.7\\pm0.7_{\\mathrm{stat}}\\pm0.2_{\\mathrm{syst}}$. The integral flux above 180 GeV is $(3.9\\pm0.8_{\\mathrm{stat}}\\pm1.0_{\\mathrm{syst}})\\times 10^{-8}$ m$^{-2}$ s$^{-1}$, corresponding to 1.6% of the Crab Nebula flux on average. The multiwavelength spectral energy distribution of the source suggests that 1ES 1741+196 is an extreme-high-frequency-peaked BL Lacertae object. The observations analysed in this paper extend over a period of six years, during which time no strong flares were observed in any band. This analysis is therefore one of the few characterizations of a blazar in a non-flaring state.

  20. BL Lacertae objects and radio-loud quasars within an evolutionary unified scheme

    International Nuclear Information System (INIS)

    On the basis of a joint radio-optical analysis, different amounts of cosmological luminosity evolution in the optical band for flat- and steep-spectrum radio-loud quasars are found. Specifically, a slower evolution for the flat-spectrum quasars, evidence of a sluggish beamed component in the optical band additional to the canonical isotropic continuum is shown. The persistence of the beamed component in terms of a spectral evolution with the Doppler factor increasing somewhat in cosmic time is interpreted. The BL Lacertae objects are placed into this framework and an evolutionary unified scheme is proposed maintaining spectral and statistical continuity of BL Lacs with flat-spectrum quasars. Supportive observational evidence, and clues for the parent population, are discussed. 57 refs

  1. X-ray Emission of Low-Energy-Peaked BL Lacertae Objects

    International Nuclear Information System (INIS)

    Presented here is an analysis of X-ray observations of the following seven low-energy-peaked BL Lacertae objects: BL Lacertae, S5 0716+71, W Comae, 3C 66A, S4 0954+65, OJ 287, and AO 0235+16. The spectral data for these objects were taken from observations by the XMM-Newton and/or Chandra X-ray observatories. These objects are being analyzed in an effort to reanalyze all XMM-Newton and Chandra data of low-energy BL Lacs, similar to the efforts of Perlman et al.[4] for high energy BL Lacs. The objects were studied in an effort to understand the nature of the X-ray and multi-waveband emissions in these objects, study the shape of the spectra, and compare the observations of low-energy-peaked BL Lacs to previous observations of these objects and also to observations of high-energy-peaked BL Lacs. Light curves and spectra were analyzed to look for evidence of spectral variability in the objects and as a comparison to previous research on these objects. Most data shows both synchrotron and Inverse-Compton emission, though only little correlation was seen between the emission strength and the spectral slope. Our data is generally well-fitted to a broken power law model with distinct bimodality seen in the first spectral index (six observations with Γ1∼0.4 and four observations with Γ1∼3.0), a break in energy between 0.6 and 1.4 keV, and a second spectral index Γ2∼2.0. None of the observations showed spectral lines, which is consistent with past results. For S5 0716+71 the XMM-Newton X-ray and optical data, along with radio data obtained from the University of Michigan Radio Astronomy Observatory (UMRAO), a spectral energy distribution was created and peak frequencies were estimated.

  2. The Binary Black Hole Scenario for the BL Lacertae Object AO 0235+16

    Institute of Scientific and Technical Information of China (English)

    G. E. Romero; Jun-Hui Fan; S. E. Nuza

    2003-01-01

    Recent analysis of the long term radio light curve of the extremely variable BL Lacertae object AO 0235t16 by Raiteri et al. have revealed the presence of recurrent outbursts with a period of ~ 5.7 ± 0.5yr. Periodicity analysis of the optical light curve also shows evidence for a shorter period. Here we discuss whether such a behavior can be explained by a binary black hole model where the accretion disk of one of the supermassive black holes is precessing due to the tidal effects of the companion. We estimate the mass of the accreting hole and analyze constraints on the secondary mass and the orbital parameters of the system. It is possible to provide a viable interpretation of the available multiwavelength data.

  3. Discovery of very high energy gamma-ray emission from the low-frequency peaked BL Lac object BL Lacertae

    CERN Document Server

    Albert, J; Anderhub, H; Antoranz, P; Armada, A; Baixeras, C; Barrio, J A; Bartko, H; Bastieri, D; Becker, J K; Bednarek, W; Berger, K; Bigongiari, C; Biland, A; Böck, R K; Bordas, P; Bosch-Ramon, V; Bretz, T; Britvitch, I; Camara, M; Carmona, E; Chilingarian, A; Coarasa, J A; Commichau, S; Contreras, J L; Cortina, J; Costado, M T; Curtef, V; Danielyan, V; Dazzi, F; Deangelis, A; Delgado, C; Delosreyes, R; Delotto, B; Domingo-Santamaria, E; Dorner, D; Doro, M; Errando, M; Fagiolini, M; Ferenc, D; Fernndez, E; Firpo, R; Flix, J; Fonseca, M V; Font, L; Fuchs, M; Galante, N; Garca-Lopez, R; Garczarczyk, M; Gaug, M; Giller, M; Göbel, F; Hakobyan, D; Hayashida, M; Hengstebeck, T; Herrero, A; Höhne, D; Hose, J; Hsu, C C; Jacon, P; Jogler, T; Kosyra, R; Kranich, D; Kritzer, R; Laille, A; Lindfors, E; Lombardi, S; Longo, F; López, J; López, M; Lorenz, E; Majumdar, P; Maneva, G; Mannheim, K; Mansutti, O; Mariotti, M; Martínez, M; Mazin, D; Merck, C; Meucci, M; Meyer, M; Miranda, J M; Mirzoyan, R; Mizobuchi, S; Moralejo, A; Nilsson, K; Ninkovic, J; Oa-Wilhelmi, E; Otte, N; Oya, I; Paneque, D; Panniello, M; Paoletti, R; Paredes, J M; Pasanen, M; Pascoli, D; Pauss, F; Pegna, R; Persic, M; Peruzzo, L; Piccioli, A; Poller, M; Puchades, N; Prandini, E; Raymers, A; Rhode, W; Rib, M; Rico, J; Rissi, M; Robert, A; Rugamer, S; Saggion, A; Sánchez, A; Sartori, P; Scalzotto, V; Scapin, V; Schmitt, R; Schweizer, T; Shayduk, M; Shinozaki, K; Shore, S N; Sidro, N; Sillanp, A; Sobczynska, D; Stamerra, A; Stark, L S; Takalo, L; Temnikov, P; Tescaro, D; Teshima, M; Tonello, N; Torres, D F; Turini, N; Vankov, H; Vitale, V; Wagner, R M; Wibig, T; Wittek, W; Zandanel, F; Zanin, R; Zapatero, J

    2007-01-01

    The low-frequency peaked BL Lac (LBL) object BL Lacertae was observed with the MAGIC telescope from August to December 2005 (22.2 hrs), and from July to September 2006 (26.0 hrs). A very high energy (VHE) gamma-ray signal was discovered with a 5.1 sigma excess in the 2005 data. Above 200 GeV, an integral flux of (0.6+-0.2)x10^{-11} cm^{-2} s^{-1} was measured, corresponding to approximate by 3 of the Crab flux. The differential spectrum between 150 and 900 GeV is rather steep, with a photon index of -3.6+-0.5. For the first time, a clear detection of VHE gamma-ray emission from an LBL object was obtained with a signal below previous upper limits. During the observation, the light curve shows no large fluctuation. On the contrary, the 2006 data show no significant excess. This drop in flux follows the observed trend in optical activity.

  4. Six-year Optical Monitoring of BL Lacertae Object 1ES 0806+52.4

    CERN Document Server

    Man, Zhongyi; Wu, Jianghua; Zhou, Xu; Yuan, Qirong

    2014-01-01

    We present the results of the first systematic long-term multi-color optical monitoring of the BL Lacertae object 1ES 0806+52.4. The monitoring was performed in multiple passbands with a 60/90 cm Schmidt telescope from December 2005 to February 2011. The overall brightness of this object decreased from 2005 December to 2008 December, and regained after that. A sharp outburst probably occurred around the end of our monitoring program. Overlapped on the long-term trend are some short-term small-amplitude oscillations. No intra-night variability was found in the object, which is in accord with the historical observations before 2005. By investigating the color behavior, we found strong bluer-when-brighter chromatism for the long-term variability of 1ES 0806+52.4. The total amplitudes at the c, i and o bands are 1.18, 1.12, and 1.02 mags, respectively. The amplitudes tend to increase toward shorter wavelength, which may be the major cause of bluer-when-brighter. Such bluer-when-brighter is also found in other bla...

  5. Variability of the BL Lacertae objects PKS 2155 - 304 and OJ 287 in the far-ultraviolet

    International Nuclear Information System (INIS)

    All the ultraviolet spectra of the two bright BL Lacertae objects PKS 2155 - 304 and OJ 287 taken with the International Ultraviolet Explorer in the period 1978-1984 are examined. For each spectrum the best-fitting power law is determined and a correlation between spectral slope and intensity is searched for. The correlation, if present, is weak. This is discussed in terms of models of the continuum emission of active galactic nuclei. 31 references

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

    International Nuclear Information System (INIS)

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

  7. Short Timescale Photometric and Polarimetric Behavior of two BL Lacertae Type Objects

    CERN Document Server

    Covino, S; Foschini, L; Sandrinelli, A; Tavecchio, F; Treves, A; Zhang, H; de Almeida, U Barres; Bonnoli, G; Boettcher, M; Cecconi, M; D'Ammando, F; di Fabrizio, L; Giarrusso, M; Leone, F; Lindfors, E; Lorenzi, V; Molinari, E; Paiano, S; Prandini, E; Raiteri, C M; Stamerra, A; Tagliaferri, G

    2015-01-01

    Blazars are astrophysical sources whose emission is dominated by non-thermal processes, typically interpreted as synchrotron and inverse Compton emission. Although the general picture is rather robust and consistent with observations, many aspects are still unexplored. Polarimetric monitoring can offer a wealth of information about the physical processes in blazars. Models with largely different physical ingredients can often provide almost indistinguishable predictions for the total flux, but usually are characterized by markedly different polarization properties. We explore, with a pilot study, the possibility to derive structural information about the emitting regions of blazars by means of a joint analysis of rapid variability of the total and polarized flux at optical wavelengths. Short timescale (from tens of seconds to a couple of minutes) optical linear polarimetry and photometry for two blazars, BL Lacertae and PKS 1424+240, was carried out with the PAOLO polarimeter at the 3.6m Telescopio Nazionale ...

  8. Short timescale photometric and polarimetric behavior of two BL Lacertae type objects

    International Nuclear Information System (INIS)

    Context. Blazars are astrophysical sources whose emission is dominated by non-thermal processes, typically interpreted as synchrotron and inverse Compton emission. Although the general picture is rather robust and consistent with observations, many aspects are still unexplored. Aims. Polarimetric monitoring can offer a wealth of information about the physical processes in blazars. Models with largely different physical ingredients can often provide almost indistinguishable predictions for the total flux, but usually are characterized by markedly different polarization properties. We explore, with a pilot study, the possibility to derive structural information about the emitting regions of blazars by means of a joint analysis of rapid variability of the total and polarized flux at optical wavelengths. Methods. Short timescale (from tens of seconds to a couple of minutes) optical linear polarimetry and photometry for two blazars, BL Lacertae and PKS 1424+240, was carried out with the PAOLO polarimeter at the 3.6 m Telescopio Nazionale Galileo. Several hours of almost continuous observations were obtained for both sources. Results. Our intense monitoring allowed us to draw strongly different scenarios for BL Lacertae and PKS 1424+240, with the former characterized by intense variability on time-scales from hours to a few minutes and the latter practically constant in total flux. Essentially the same behavior is observed for the polarized flux and the position angle. The variability time-scales turned out to be as short as a few minutes, although involving only a few percent variation of the flux. The polarization variability time-scale is generally consistent with the total flux variability. Total and polarized flux appear to be essentially uncorrelated. However, even during our relatively short monitoring, different regimes can be singled out. Conclusions. No simple scenario is able to satisfactorily model the very rich phenomenology exhibited in our data. As a

  9. THE LACK OF TORUS EMISSION FROM BL LACERTAE OBJECTS: AN INFRARED VIEW OF UNIFICATION WITH WISE

    International Nuclear Information System (INIS)

    We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number (∼102) of BL Lac objects—low-luminosity active galactic nuclei (AGNs) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions. In other BL Lac objects, however, the jet is not strong enough to completely dilute the rest of the AGN emission. We do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. The lack of observable torus emission is consistent with suggestions that BL Lac objects are fed by radiatively inefficient accretion disks. Implications for the 'nature versus nurture' debate for FR I and FR II radio galaxies are briefly discussed. Our study supports the notion that, beyond orientation, accretion rate plays an important role in AGN unification.

  10. The Lack of Torus Emission from BL Lacertae Objects: An Infrared View of Unification with WISE

    OpenAIRE

    Plotkin, Richard M.; Anderson, Scott F.; Brandt, W. N.; Markoff, Sera; Shemmer, Ohad; Wu, Jianfeng

    2011-01-01

    We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number ($\\sim10^2$) of BL Lac objects --- low-luminosity Active Galactic Nuclei (AGN) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions. In other BL Lac objects, however, the jet is not strong enough to completely dilute the rest ...

  11. The Lack of Torus Emission from BL Lacertae Objects: An Infrared View of Unification with WISE

    CERN Document Server

    Plotkin, Richard M; Brandt, W N; Markoff, Sera; Shemmer, Ohad; Wu, Jianfeng

    2011-01-01

    We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number ($\\sim10^2$) of BL Lac objects --- low-luminosity Active Galactic Nuclei (AGN) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions. In other BL Lac objects, however, the jet is not strong enough to completely dilute the rest of the AGN emission. We do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. The lack of observable torus emission is consistent with suggestions that BL Lac objects are fed by radiatively inefficient accretion disks. Implications for the "nature vs. nurture" debate for FR I and FR II radio galaxies are briefly discussed. Our study supports the notion that, beyond orientation, accretion rate plays an important role in AGN unification.

  12. RATAN-600 multi-frequency data for the BL Lacertae objects

    Science.gov (United States)

    Mingaliev, M. G.; Sotnikova, Yu. V.; Udovitskiy, R. Yu.; Mufakharov, T. V.; Nieppola, E.; Erkenov, A. K.

    2014-12-01

    Aims: We present a new catalogue of the RATAN-600 multi-frequency measurements for BL Lac objects. The purpose of this catalogue is to compile the BL Lac multi-frequency data that is acquired with the RATAN-600 simultaneously at several frequencies. The BL Lac objects emit a strongly variable and polarized non-thermal radiation across the entire electromagnetic spectrum from radio to γ rays and represent about 1% of known AGNs. They belong to the blazar population and differ from other blazars' featureless optical spectrum, which sometimes have absorption lines, or have weak and narrow emission lines. One of the most effective ways of studying the physics of BL Lacs is the use of simultaneous multi-frequency data. Methods: The multi-frequency broadband radio spectrum was obtained simultaneously with an accuracy of up to 1-2 min for four to six frequencies: 1.1, 2.3, 4.8, 7.7, 11.2, and 21.7 GHz. The catalogue is based on the RATAN-600 observations and on the data from: equatorial coordinate and redshift, R-band magnitude, synchrotron peak frequency, SED classes, and object type literature. Results: The present version of the catalogue contains RATAN-600 flux densities measurements over nine years (2006-2014), radio spectra at different epochs, and their parameters of the catalogue for more than 300 BL Lacs objects and candidates. The BL Lacs list is constantly updated with new observational data of RATAN-600. The catalogue is presented in interactive form and available at Special Astrophysical Observatory of the Russian Academy of Sciences website http://www.sao.ru/blcat/

  13. Rapid X-ray Variability of the BL Lacertae Object PKS 2155-304

    OpenAIRE

    Zhang, Y.H.; Celotti, A.; Treves, A.; Chiappetti, L.; Ghisellini, G.; L. Maraschi(INAF National Institute for Astrophysics, I-00136 Rome, Italy); Pian, E.; Tagliaferri, G.; Tavecchio, F.; C. M. Urry

    1999-01-01

    (Abridged) We present a detailed power density spectrum and cross-correlation analysis of the X-ray light curves of the BL Lac object PKS 2155-304, observed with BeppoSAX in 1997 and 1996, aimed at exploring the rapid variability properties and the inter-band cross correlations in the X-rays. We also perform the same analysis on the (archival) X-ray light curve obtained with ASCA in 1994.

  14. BROAD Lyα EMISSION FROM THREE NEARBY BL LACERTAE OBJECTS

    International Nuclear Information System (INIS)

    We present far-UV HST/COS spectra of four nearby BL Lac objects. BL Lac spectra are dominated by a smooth, power-law continuum which arises in a relativistic jet. However, the spectra are not necessarily featureless; weak, broad- and/or narrow-line emission is sometimes seen in high-quality optical spectra. We present detections of Lyα emission in HST/COS spectra of Mrk 421 (z = 0.030) and PKS 2005-489 (z = 0.071) as well as an archival HST/GHRS observation of Mrk 501 (z = 0.0337). Archival HST/STIS observations of PKS 2155-304 (z = 0.116) show no Lyα emission to a very low upper limit. Using the assumption that the broad-line region (BLR) clouds are symmetrically placed around the active galactic nucleus (AGN), we use these measured Lyα emission features to constrain either the relativistic Γ values for the ionizing continuum produced by the jet (in the ionization-bounded case) or the mass of warm gas (in the density-bounded case). While realistic Γ values can be obtained for all four cases, the values for Mrk 421 and PKS 2155-304 are high enough to suggest that covering factors of BLR clouds of ∼1%-2% might be required to provide consistency with earlier values of Doppler boosting and viewing angles suggested for this class of BL Lacs. This discrepancy also exists in the case of M 87, where the amount of Doppler boosting in our direction is expected to be minimal, again suggestive of a small covering factor of BLR clouds. If, as these small covering factors might suggest, the assumptions of a density-bounded model could be more correct, then the observed Lyα luminosities require that BL Lac/FR 1 nuclei possess very little warm gas (10-4 to 10-5 Msun) as suggested by Guilbert et al. If these clouds are in pressure balance with a hotter (∼106 K) gas, the BLR contains too little mass to power the AGN by accretion alone.

  15. The Optical Microvariability and Spectral Changes of the BL Lacertae Object S5 0716+714

    Indian Academy of Sciences (India)

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

    2011-03-01

    The BL Lac object S5 0716+714 was monitored in the optical band during October 2008, December 2008 and February 2009. We achieved a best temporal resolution of about 5 min in the bands. The source was active during the whole monitoring campaign. It showed microvariability in 13 days out of 14 days of observation. Four fast flares were observed with amplitudes ranging from 0.3–0.75 mag. The overall amplitude changes during the whole campaign are ∼ 0. 89, ∼ 0. 80, ∼ 0. 73, and ∼ 0. 51. On internight time scales, strong bluer-when-brighter chromatism was found while different spectral behaviours were found on intranight time scales.

  16. The collective emission of electromagnetic waves from astrophysical jets - Luminosity gaps, BL Lacertae objects, and efficient energy transport

    Science.gov (United States)

    Baker, D. N.; Borovsky, Joseph E.; Benford, Gregory; Eilek, Jean A.

    1988-01-01

    A model of the inner portions of astrophysical jets is constructed in which a relativistic electron beam is injected from the central engine into the jet plasma. This beam drives electrostatic plasma wave turbulence, which leads to the collective emission of electromagnetic waves. The emitted waves are beamed in the direction of the jet axis, so that end-on viewing of the jet yields an extremely bright source (BL Lacertae object). The relativistic electron beam may also drive long-wavelength electromagnetic plasma instabilities (firehose and Kelvin-Helmholtz) that jumble the jet magnetic field lines. After a sufficient distance from the core source, these instabilities will cause the beamed emission to point in random directions and the jet emission can then be observed from any direction relative to the jet axis. This combination of effects may lead to the gap turn-on of astrophysical jets. The collective emission model leads to different estimates for energy transport and the interpretation of radio spectra than the conventional incoherent synchrotron theory.

  17. Longterm Optical Monitoring of Bright BL Lacertae Objects with ATOM: Spectral Variability and Multiwavelength Correlations

    CERN Document Server

    Wierzcholska, Alicja; Stawarz, Łukasz; Wagner, Stefan; Hauser, Marcus

    2014-01-01

    Blazars are the established sources of an intense and variable non-thermal radiation extending from radio wavelengths up to HE and VHE gamma-rays. Understanding the spectral evolution of blazars in selected frequency ranges, as well as multi-frequency correlations in various types of blazar sources, is of a primary importance for constraining the blazar physics. Here we present the results of a long-term optical monitoring of a sample of 30 blazars of the BL Lac type. We study the optical color-magnitude correlation patterns emerging in the analyzed sample, and compare the optical properties of the targets with the high-energy gamma-ray and high-frequency radio data. The optical observations were carried out in R and B filters using ATOM telescope. Each object was observed during at least 20 nights in the period 2007-2012. We find significant global color-magnitude correlations in 40 % of the sample. The sources which do not display any clear chromatism often do exhibit bluer-when-brighter (bwb) behavior but ...

  18. Gamma-ray and multiwaveband emission from gamma-ray-loud BL Lacertae objects

    International Nuclear Information System (INIS)

    We have collected 18 γ-ray-loud BL Lac with observed data in multiwaveband, we find that γ-ray flux densities correlate better with the near-IR flux densities than those with the optical or x-ray flux densities. There is no correlation between γ-ray and radio flux densities. Possible constraints on the γ-ray emission mechanism are discussed. We suggest that the main γ-ray radiation mechanism is probably the synchrotron self-Compton process. The inverse Compton scattering of the radiation from hot circumscribe dust, by beamed ultrarelativistic electrons, is likely to be an important complementary mechanism

  19. The HST Survey of BL Lacertae Objects: Morphological Properties of Low redshift Host Galaxies

    CERN Document Server

    Falomo, R; Treves, A; Urry, C M; 10.1086/317044

    2009-01-01

    We report on the optical properties of a sample of 30 BL Lac host galaxies in the redshift range $0.03BL Lac nucleus is well centered in the main body of its host galaxy, a result that argues strongly against the microlensing hypothesis for any significant fraction of the population. A search for faint sub-structures in the host galaxies has not revealed notable signatures of tidal distortions or sub-components (faint disks, bars, X features, etc.), and with only one exception, there are no prominent dusty features in the central regions. Instead, the B...

  20. Observations of BL Lacertae with MAGIC telescope

    Directory of Open Access Journals (Sweden)

    E. J. Lindfors

    2008-01-01

    Full Text Available BL Lacertae fue observado con el telescopio MAGIC de agosto a diciembre de 2005 (22.2 horas y de julio a septiembre de 2006 (26.0 horas. En 2005 se detectó, con un nivel de significación 5.1 σ, una fuerte emisión de rayos γ de muy alta energía (VHE. BL Lacertae es el primer objeto BL Lac con un pico de emisión a bajas frecuencias, en el cual se detecta este tipo de emisión. En los datos de 2006, no hay detección en la región de los rayos γ, lo que se atribuye a un menor nivel de flujo en este periodo. En este trabajo mostramos que también se observa una caida en el flujo óptico y milimétrico, lo cual sugiere una conexión entre estas tres bandas de emisión.

  1. Long-term optical and radio variability of BL Lacertae

    Science.gov (United States)

    Guo, Y. C.; Hu, S. M.; Xu, C.; Liu, C. Y.; Chen, X.; Guo, D. F.; Meng, F. Y.; Xu, M. T.; Xu, J. Q.

    2015-04-01

    Well-sampled optical and radio light curves of BL Lacertae in B, V, R, I bands and 4.8, 8.0, 14.5 GHz from 1968 to 2014 were presented in this paper. A possible 1.26 ± 0.05 yr period in optical bands and a 7.50 ± 0.15 yr period in radio bands were detected based on discrete correlation function, structure function as well as Jurkevich method. Correlations among different bands were also analyzed and no reliable time delay was found between optical bands. Very weak correlations were detected between V band and radio bands. However, in radio bands the variation at low frequency lagged that at high frequency obviously. The spectrum of BL Lacertae turned mildly bluer when the object turned brighter, and stronger bluer-when-brighter trends were found for short flares. A scenario including a precessing helical jet and periodic shocks was put forward to interpret the variation characteristics of BL Lacertae.

  2. An HST/COS observation of broad Lyα emission and associated absorption lines of the BL Lacertae object H 2356-309

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Taotao [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Danforth, Charles W.; Stocke, John T.; Shull, J. Michael [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Buote, David A. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Canizares, Claude R. [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Gastaldello, Fabio, E-mail: fangt@xmu.edu.cn [IASF-Milano, INAF, via Bassini 15, Milan I-20133 (Italy)

    2014-11-01

    Weak spectral features in BL Lacertae objects (BL Lacs) often provide a unique opportunity to probe the inner region of this rare type of active galactic nucleus. We present a Hubble Space Telescope/Cosmic Origins Spectrograph observation of the BL Lac H 2356-309. A weak Lyα emission line was detected. This is the fourth detection of a weak Lyα emission feature in the ultraviolet (UV) band in the so-called high-energy peaked BL Lacs, after Stocke et al. Assuming the line-emitting gas is located in the broad line region (BLR) and the ionizing source is the off-axis jet emission, we constrain the Lorentz factor (Γ) of the relativistic jet to be ≥8.1 with a maximum viewing angle of 3.°6. The derived Γ is somewhat larger than previous measurements of Γ ≈ 3-5, implying a covering factor of ∼3% of the line-emitting gas. Alternatively, the BLR clouds could be optically thin, in which case we constrain the BLR warm gas to be ∼10{sup –5} M {sub ☉}. We also detected two H I and one O VI absorption lines that are within |Δv| < 150 km s{sup –1} of the BL Lac object. The O VI and one of the H I absorbers likely coexist due to their nearly identical velocities. We discuss several ionization models and find a photoionization model where the ionizing photon source is the BL Lac object that can fit the observed ion column densities with reasonable physical parameters. This absorber can either be located in the interstellar medium of the host galaxy or in the BLR.

  3. Optical and Radio Variability of BL Lacertae

    CERN Document Server

    Gaur, Haritma; Bachev, R; Strigachev, A; Semkov, E; Wiita, Paul J; Volvach, A E; Gu, Minfeng; Agarwal, A; Agudo, I; Aller, M F; Aller, H D; Kurtanidze, O M; Kurtanidze, S O; Lahteenmaki, A; Peneva, S; Nikolashvili, M G; Sigua, L A; Tornikoski, M; Volvach, L N

    2015-01-01

    We observed the prototype blazar, BL Lacertae, extensively in optical and radio bands during an active phase in the period 2010--2013 when the source showed several prominent outbursts. We searched for possible correlations and time lags between the optical and radio band flux variations using multifrequency data to learn about the mechanisms producing variability. During an active phase of BL Lacertae, we searched for possible correlations and time lags between multifrequency light curves of several optical and radio bands. We tried to estimate any possible variability timescales and inter-band lags in these bands. We performed optical observations in B, V, R and I bands from seven telescopes in Bulgaria, Georgia, Greece and India and obtained radio data at 36.8, 22.2, 14.5, 8 and 4.8 GHz frequencies from three telescopes in Ukraine, Finland and USA. Significant cross-correlations between optical and radio bands are found in our observations with a delay of cm-fluxes with respect to optical ones of ~250 days...

  4. Discovery of a new BL Lacertae object /1E 1402.3 + 0416/ with the Einstein Observatory

    Science.gov (United States)

    Stocke, J.; Liebert, J.; Stockman, H.; Danziger, J.; Lub, J.; Maccacaro, T.; Griffiths, R.; Giommi, P.

    1982-01-01

    It is noted that only one BL Lac object, designated 1E 1402.3 + 0416, has so far been discovered as part of an optical identification program for a complete sample of faint X-ray sources detected with the Einstein Observatory. Consistent with previously X-ray-discovered BL Lacs, this object is blue and radio weak (17 mJy at 6 cm). It is pointed out that the percentage of BL Lacs in the faint extragalactic X-ray sample (2%) is smaller than the percentage at higher X-ray fluxes (6%). Over the same range in X-ray flux, the percentage of emission-line active galaxy nuclei (QSO + Seyferts) rises from 40% to 74%). This is seen as suggesting that BL Lacs do not evolve in a manner similar to quasars and are, therefore, not substantial contributors to the X-ray background.

  5. Seven-Year Multi-Colour Optical Monitoring of BL Lacertae Object S5 0716+714

    Indian Academy of Sciences (India)

    Jianghua Wu; Yan Dai; Xu Zhou; Jun Ma

    2014-09-01

    We monitored the BL Lac object S5 0716+714 in five intermediate optical passbands from 2004 September to 2011 April. The object was active most of the time and intra-day variability was frequently observed. The total variation amplitude tended to decrease with decreasing frequency. Strong bluer-when-brighter chromatism was observed on both long and short timescales.

  6. Optical and radio variability of BL Lacertae

    Science.gov (United States)

    Gaur, H.; Gupta, A. C.; Bachev, R.; Strigachev, A.; Semkov, E.; Wiita, P. J.; Volvach, A. E.; Gu, M. F.; Agarwal, A.; Agudo, I.; Aller, M. F.; Aller, H. D.; Kurtanidze, O. M.; Kurtanidze, S. O.; Lähteenmäki, A.; Peneva, S.; Nikolashvili, M. G.; Sigua, L. A.; Tornikoski, M.; Volvach, L. N.

    2015-10-01

    Context. We extensively observed the prototype blazar, BL Lacertae, in optical and radio bands during an active phase in the period 2010-2013 when the source showed several prominent outbursts. We searched for possible correlations and time lags between the optical and radio band flux variations using multi-frequency data to learn about the mechanisms producing variability. Aims: During an active phase of BL Lacertae, we searched for possible correlations and time lags between multi-frequency light curves of several optical and radio bands. We tried to estimate any possible variability timescales and inter-band lags in these bands. Methods: We performed optical observations in B, V, R, and I-bands from seven telescopes in Bulgaria, Georgia, Greece, and India and obtained radio data at 36.8, 22.2, 14.5, 8, and 4.8 GHz frequencies from three telescopes in Crimea, Finland, and USA. Results: Significant cross-correlations between optical and radio bands are found in our observations with a delay of cm-fluxes with respect to optical bands of ~250 days. The optical and radio light curves do not show any significant timescales of variability. BL Lacertae showed many optical "mini-flares" on short timescales. Variations on longer term timescales are mildly chromatic with the superposition of many strong optical outbursts. In radio bands, the amplitude of variability is frequency dependent. Flux variations at higher radio frequencies lead the lower frequencies by days or weeks. Conclusions: The optical variations are consistent with being dominated by a geometric scenario where a region of emitting plasma moves along a helical path in a relativistic jet. The frequency dependence of the variability amplitude supports an origin of the observed variations intrinsic to the source. Tables of the light curves are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/582/A103

  7. Multifrequency-spectral behavior of the BL Lacertae objects OI 90.4 and 3C 66A

    Science.gov (United States)

    Worrall, D. M.; Rodriguez-Espinosa, J. M.; Puschell, J. J.; Bruhweiler, F. C.; Miller, H. R.; Aller, M. F.; Aller, H. D.

    1984-01-01

    Single-epoch multifrequency data for the BL Lac objects OI 90.4 and 3C 66A, spanning radio through ultraviolet wavelengths, are presented, as well as other measurements relevant to intensity and spectral-shape variability. Both BL Lac objects exhibit spectral curvature in the infrared-to-ultraviolet region, a properity that is inferred to be usual for this object class. Variability in the ultraviolet spectral index of OI 90.4 is found, whereas the spectral index of 3C 66A is the same in two observations 17 months apart. A synchrotron self-Compton jet model is applied to each BL Lac object. The OI 90.4 data are found to be best satisfied by a jet with a relatively high degree of relativistic beaming, but emission at frequencies below about 50 GHz is not described by the model. Furthermore, 3C 66A may not always undergo strong relativistic beaming, and the model may incorporate the small fraction of the total radio emission below about 20 GHz that is from within about 1.5 milliarcsec of the core.

  8. Optical variability of the BL Lacertae object GC 0109+224. Multiband behaviour and time scales from a 7-years monitoring campaign

    CERN Document Server

    Ciprini, S; Raiteri, C M; Villata, M; Ibrahimov, M A; Nucciarelli, G; Lanteri, L

    2003-01-01

    We present the most continuous data base of optical $BVR_{c}I_{c}$ observations ever published on the BL Lacertae object GC 0109+224, collected mainly by the robotic telescope of the Perugia University Observatory in the period November 1994-February 2002. These observations have been complemented by data from the Torino Observatory, collected in the period July 1995-January 1999, and Mt. Maidanak Observatory (December 2000). GC 0109+224 showed rapid optical variations and six major outbursts were observed at the beginning and end of 1996, in fall 1998, at the beginning and at the end of 2000, and at the beginning of 2002. Fast and large-amplitude drops characterized its flux behaviour. The $R_c$ magnitude ranged from 13.3 (16.16 mJy) to 16.46 (0.8 mJy), with a mean value of 14.9 (3.38 mJy). In the periods where we collected multi-filter observations, we analyzed colour and spectral indexes, and the variability patterns during some flares. The long-term behaviour seems approximatively achromatic, but during s...

  9. On the Location of the Gamma-ray Emission in the 2008 Outburst in the BL Lacertae Object AO 0235+164 through Observations across the Electromagnetic Spectrum

    CERN Document Server

    Agudo, Ivan; Jorstad, Svetlana G; Larionov, Valeri M; Gomez, Jose L; Lahteenmaki, Anne; Smith, Paul S; Nilsson, Kari; Readhead, Anthony C S; Aller, Margo F; Heidt, Jochen; Gurwell, Mark; Thum, Clemens; Wehrle, Ann E; Aller, Hugh D; Benitez, Erika; Blinov, Dmitriy A; Hagen-Thorn, Vladimir A; Hiriart, David; Jannuzi, Buell T; Joshi, Manasvita; Lindfors, Elina; Molina, Sol N; Morozova, Daria A; Nieppola, Elina; Olmstead, Alice R; Reinthal, Riho; Roca--Sogorb, Mar; Schmidt, Gary D; Sillanpaa, Aimo; Takalo, Leo; Taylor, Brian; Tornikoski, Merja; Troitsky, Ivan S; Zook, Alma C; Wiesemeyer, Helmut

    2011-01-01

    We present observations of a major outburst at centimeter, millimeter, optical, X-ray, and gamma-ray wavelengths of the BL Lacertae object AO 0235+164. We analyze the timing of multi-waveband variations in the flux and linear polarization, as well as changes in Very Long Baseline Array (VLBA) images at 7mm with 0.15 milliarcsecond resolution. The association of the events at different wavebands is confirmed at high statistical significance by probability arguments and Monte-Carlo simulations. A series of sharp peaks in optical linear polarization, as well as a pronounced maximum in the 7 mm polarization of a superluminal jet knot, indicate rapid fluctuations in the degree of ordering of the magnetic field. These results lead us to conclude that the outburst occurred in the jet both in the quasi-stationary "core" and in the superluminal knot, both parsecs downstream of the supermassive black hole. We interpret the outburst as a consequence of the propagation of a disturbance, elongated along the line of sight ...

  10. Discovery and characterization of the first low-peaked and intermediate-peaked BL Lacertae objects in the very high energy {gamma}-ray regime

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Karsten

    2009-12-19

    20 years after the discovery of the Crab Nebula as a source of very high energy {gamma}-rays, the number of sources newly discovered above 100 GeV using ground-based Cherenkov telescopes has considerably grown, at the time of writing of this thesis to a total of 81. The sources are of different types, including galactic sources such as supernova remnants, pulsars, binary systems, or so-far unidentified accelerators and extragalactic sources such as blazars and radio galaxies. The goal of this thesis work was to search for {gamma}-ray emission from a particular type of blazars previously undetected at very high {gamma}-ray energies, by using the MAGIC telescope. Those blazars previously detected were all of the same type, the so-called high-peaked BL Lacertae objects. The sources emit purely non-thermal emission, and exhibit a peak in their radio-to-X-ray spectral energy distribution at X-ray energies. The entire blazar population extends from these rare, low-luminosity BL Lacertae objects with peaks at X-ray energies to the much more numerous, high-luminosity infrared-peaked radio quasars. Indeed, the low-peaked sources dominate the source counts obtained from space-borne observations at {gamma}-ray energies up to 10 GeV. Their spectra observed at lower {gamma}-ray energies show power-law extensions to higher energies, although theoretical models suggest them to turn over at energies below 100 GeV. This opened the quest for MAGIC as the Cherenkov telescope with the currently lowest energy threshold. In the framework of this thesis, the search was focused on the prominent sources BL Lac, W Comae and S5 0716+714, respectively. Two of the sources were unambiguously discovered at very high energy {gamma}-rays with the MAGIC telescope, based on the analysis of a total of about 150 hours worth of data collected between 2005 and 2008. The analysis of this very large data set required novel techniques for treating the effects of twilight conditions on the data quality

  11. Discovery and characterization of the first low-peaked and intermediate-peaked BL Lacertae objects in the very high energy γ-ray regime

    International Nuclear Information System (INIS)

    20 years after the discovery of the Crab Nebula as a source of very high energy γ-rays, the number of sources newly discovered above 100 GeV using ground-based Cherenkov telescopes has considerably grown, at the time of writing of this thesis to a total of 81. The sources are of different types, including galactic sources such as supernova remnants, pulsars, binary systems, or so-far unidentified accelerators and extragalactic sources such as blazars and radio galaxies. The goal of this thesis work was to search for γ-ray emission from a particular type of blazars previously undetected at very high γ-ray energies, by using the MAGIC telescope. Those blazars previously detected were all of the same type, the so-called high-peaked BL Lacertae objects. The sources emit purely non-thermal emission, and exhibit a peak in their radio-to-X-ray spectral energy distribution at X-ray energies. The entire blazar population extends from these rare, low-luminosity BL Lacertae objects with peaks at X-ray energies to the much more numerous, high-luminosity infrared-peaked radio quasars. Indeed, the low-peaked sources dominate the source counts obtained from space-borne observations at γ-ray energies up to 10 GeV. Their spectra observed at lower γ-ray energies show power-law extensions to higher energies, although theoretical models suggest them to turn over at energies below 100 GeV. This opened the quest for MAGIC as the Cherenkov telescope with the currently lowest energy threshold. In the framework of this thesis, the search was focused on the prominent sources BL Lac, W Comae and S5 0716+714, respectively. Two of the sources were unambiguously discovered at very high energy γ-rays with the MAGIC telescope, based on the analysis of a total of about 150 hours worth of data collected between 2005 and 2008. The analysis of this very large data set required novel techniques for treating the effects of twilight conditions on the data quality. This was successfully achieved

  12. Statistical analysis of the temporal properties of BL Lacertae

    Science.gov (United States)

    Guo, Yu Cheng; Hu, Shao Ming; Li, Yu Tong; Chen, Xu

    2016-08-01

    A comprehensive temporal analysis has been performed on optical light curves of BL Lacertae in the B, V and R bands. The light curves were denoised by Gaussian smoothing and decomposed into individual flares using an exponential profile. The asymmetry, duration, peak flux and equivalent energy output of flares were measured and the frequency distributions presented. Most optical flares of BL Lacertae are highly symmetric, with a weak tendency towards gradual rises and rapid decays. The distribution of flare durations is not random, but consistent with a gamma distribution. Peak fluxes and energy outputs of flares all follow a log-normal distribution. A positive correlation is detected between flare durations and peak fluxes. The temporal properties of BL Lacertae provide evidence of the stochastic magnetohydrodynamic process in the accretion disc and jet.The results presented here can serve as constraints on physical models attempting to interpret blazar variations.

  13. Statistical Analysis on Temporal Properties of BL Lacertae

    Science.gov (United States)

    Guo, Yu Cheng; Hu, Shao Ming; Li, Yu Tong; Chen, Xu

    2016-04-01

    A comprehensive temporal analysis has been performed on optical light curves of BL Lacertae in B, V and R bands. The light curves were denoised by Gaussian smoothing and decomposed into individual flares using an exponential profile. Asymmetry, duration, peak flux and equivalent energy output of flares were measured and the frequency distributions are presented. Most optical flares of BL Lacertae are highly symmetric, with a weak tendency towards gradual rises and rapid decays. The distribution of flare durations is not random but consistent with a gamma distribution. Peak fluxes and energy outputs of flares all follow lognormal distribution. A positive correlation is detected between flare durations and peak fluxes. The temporal properties of BL Lacertae provide evidence of the stochastic magnetohydrodynamic process in accretion disk and jet. Results presented here can serve as constraints on physical models attempting to interpreting blazar variations.

  14. Elevated Optical Luminosity for Gamma-ray Blazar BL Lacertae

    Science.gov (United States)

    Furniss, A.; Fumagalli, M.; Hogan, M.; Kaplan, K.; Prochaska, P. X.; Williams, D. A.

    2012-06-01

    We report on the increased optical luminosity of BL Lacertae (RA=22h02m43.29s, dec=42d16m39.98s), a low-frequency-peaked gamma-ray emitting blazar at a redshift of 0.068 (3EG J2202+4225, 2FGL J2202.8+4216). We have collected regular R-band exposures for BL Lacertae as part of a larger optical monitoring program of gamma-ray-bright blazars using the Super-LOTIS (Livermore Optical Transient Imaging System) robotic telescope at the Steward Observatory on Kitt Peak, near Tucson Arizona.

  15. KEPLER OBSERVATIONS OF RAPID OPTICAL VARIABILITY IN THE BL LACERTAE OBJECT W2R1926+42

    International Nuclear Information System (INIS)

    We present the first Kepler monitoring of a strongly variable BL Lac, W2R1926+42. The light curve covers 181 days with ∼0.2% errors, 30 minute sampling and >90% duty cycle, showing numerous δI/I > 25% flares over timescales as short as a day. The flux distribution is highly skewed and non-Gaussian. The variability shows a strong rms-flux correlation with the clearest evidence to date for nonlinearity in this relation. We introduce a method to measure periodograms from the discrete autocorrelation function, an approach that may be well-suited to a wide range of Kepler data. The periodogram is not consistent with a simple power-law, but shows a flattening at frequencies below 7 × 10–5 Hz. Simple models of the power spectrum, such as a broken power law, do not produce acceptable fits, indicating that the Kepler blazar light curve requires more sophisticated mathematical and physical descriptions than currently in use.

  16. KEPLER OBSERVATIONS OF RAPID OPTICAL VARIABILITY IN THE BL LACERTAE OBJECT W2R1926+42

    Energy Technology Data Exchange (ETDEWEB)

    Edelson, R.; Mushotzky, R. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Vaughan, S. [X-ray and Observational Astronomy Group, Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Scargle, J. [Astrobiology and Space Science Division, NASA Ames Research Center, Moffet Field, CA 94035 (United States); Gandhi, P. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Malkan, M. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095-1547 (United States); Baumgartner, W., E-mail: redelson@astro.umd.edu [Laboratory for High Energy Astrophysics, NASA/GSFC, Code 662, Greenbelt, MD 20771 (United States)

    2013-03-20

    We present the first Kepler monitoring of a strongly variable BL Lac, W2R1926+42. The light curve covers 181 days with {approx}0.2% errors, 30 minute sampling and >90% duty cycle, showing numerous {delta}I/I > 25% flares over timescales as short as a day. The flux distribution is highly skewed and non-Gaussian. The variability shows a strong rms-flux correlation with the clearest evidence to date for nonlinearity in this relation. We introduce a method to measure periodograms from the discrete autocorrelation function, an approach that may be well-suited to a wide range of Kepler data. The periodogram is not consistent with a simple power-law, but shows a flattening at frequencies below 7 Multiplication-Sign 10{sup -5} Hz. Simple models of the power spectrum, such as a broken power law, do not produce acceptable fits, indicating that the Kepler blazar light curve requires more sophisticated mathematical and physical descriptions than currently in use.

  17. Location of gamma-ray Flare Emission in the Jet of the BL Lacertae Object OJ287 more than 14pc from the Central Engine

    CERN Document Server

    Agudo, Ivan; Marscher, Alan P; Larionov, Valeri M; Gomez, Jose L; Lahteenmaki, Anne; Gurwell, Mark A; 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

    2010-01-01

    We combine time-dependent multi-waveband flux and linear polarization observations with sub-milliarcsecond-scale polarimetric images at lambda=7mm of the BL Lacertae-type blazar OJ287 to locate the gamma-ray emission in prominent flares in the jet of the source >14pc 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 mm-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 mm-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 gamma-ray flare and the maximum in polarization of the second jet feature implies that the gamma-ray and mm-wave flares are co-spatial and occur >14 pc from the central engine. We also associate...

  18. The Evolving Radio Jet in BL Lacerta

    Science.gov (United States)

    Aller, H. D.; Hughes, P. A.; Aller, M. F.

    1994-05-01

    During the past 15 years, there have been at least ten outbursts at centimeter wavelengths in this extragalactic object. We describe here the flux density and linear polarization variations observed at 4.8, 8.0 and 14.5 GHz with the Michigan 26-meter telescope during the series of outbursts since 1987. The recent bursts are somewhat different from the highly polarized bursts in the early 1980s, which provided a successful quantitative test of a source model based on propagating transverse shocks in a relativistic jet. The most notable change is that the polarization position angle during polarized outbursts has increased by approximately 10 degrees. This is approximately the same shift as found in a comparison of VLBI maps taken during the same time periods by Mutel, Denn and Dryer (1994, NRAO Workshop on Compact Extragalactic Radio Sources, ed. Zensus and Kellermann, p. 191), and supports their conclusion that the orientation of the radio emitting jet in BL Lac has changed over time. Our preliminary analysis further suggests that a simple scaling of the physical parameters which gave quantitatively good fits to both the 1982 and 1983 bursts will not accurately describe the recent, relatively isolated, burst in 1991. We also note that while some bursts (e.g. in 1982, 1983 and 1991) exhibit degrees of linear polarization in excess of ten percent, other bursts (e.g. in 1980 and 1990) exhibit a very low degree of linear polarization. A common characteristic of the low polarization events is that they all exhibit high internal synchrotron self absorption (as indicated by the flux density spectra of the outbursts). This research has been supported in part by NSF grant AST-9120224.

  19. LOCATION OF γ-RAY FLARE EMISSION IN THE JET OF THE BL LACERTAE OBJECT OJ287 MORE THAN 14 pc FROM THE CENTRAL ENGINE

    International Nuclear Information System (INIS)

    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.

  20. Another look at the BL Lacertae flux and spectral variability

    OpenAIRE

    Raiteri, C. M.; Villata, M.; BRUSCHINI, L.; Capetti, A.; Kurtanidze, O. M.; Larionov, V. M.; Romano, P; Vercellone, S.; Agudo, I.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Bach, U.; Berdyugin, A.; Blinov, D. A.

    2010-01-01

    The GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) monitored BL Lacertae in 2008-2009 at radio, near-IR, and optical frequencies. During this period, high-energy observations were performed by XMM-Newton, Swift, and Fermi. We analyse these data with particular attention to the calibration of Swift UV data, and apply a helical jet model to interpret the source broad-band variability. The GASP-WEBT observations show an optical flare in 2008 February-March, and osc...

  1. A synchrotron self-Compton scenario for the very high energyγ-ray emission of the intermediate BL Lacertae object W Comae

    Institute of Scientific and Technical Information of China (English)

    Jin Zhang

    2009-01-01

    W Comae has significant variability in multi-wavelengthes, from radio to gamma-ray bands. A bright outburst in optical and X-ray bands was observed in 1998, and most recently, a strong TeV flare was detected by VERITAS in 2008. It is the first TeV intermediate-frequency-peaked BL Lacertae source. I find that both the broadband spectral energy distributions (SEDs) which were quasi-simultaneously obtained during the TeV flare and during the optical/X-ray outburst are well fit by using a single-zone synchrotron + synchrotron-self-Compton model. The satisfactory fitting requires a large beaming factor, i.e., δ~25 and δ~20 for the TeV flare and the optical/X-ray outburst, respectively, suggesting that both the optical/X-ray outburst and the TeV flare are from a relativistic jet. The size of the emission region of the TeV flare is three times larger than that of the optical/X-ray outburst, and the strength of the magnetic field for the TeV flare is~14 times smaller than that of the X-ray/optical outburst, likely indicating that the region of the TeV flare is more distant from the core than that of the X-ray/optical outburst. The inverse Compton component of the TeV flare peaks around 1.3 GeV, but it is around 0 MeV for the X-ray/optical outburst, lower than that for the TeV flare by two orders of magnitude. The model predicts that the optical/X-ray outburst might be accompanied by a strong MeV/GeV emission, but the TeV flare may be not associated with the X-ray/optical outburst. The GeV emission is critical for characterizing the SEDs of the optical/X-ray outburst and the TeV flare. The predicted GeV flux is above the sensitivity of Fermi/LAT, and it could be verified with the observations by Fermi/LAT in the near future.

  2. Clustering environments of BL Lac objects

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Aleksić, J.; Alvarez, E. A.; Antonelli, L. A.; Antoranz, P.; Asensio, M.; Backes, M.; Barrio, J. A.; Bastieri, D.; Becerra González, J.; Bednarek, W.; Berdyugin, A.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnoli, G.; Borla Tridon, D.; Braun, I.; Bretz, T.; Cañellas, A.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Cossio, L.; Covino, S.; Dazzi, F.; de Angelis, A.; de Caneva, G.; de Cea Del Pozo, E.; de Lotto, B.; Delgado Mendez, C.; Diago Ortega, A.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Elsaesser, D.; Ferenc, D.; Fonseca, M. V.; Font, L.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido, D.; Giavitto, G.; Godinović, N.; Hadasch, D.; Häfner, D.; Herrero, A.; Hildebrand, D.; Höhne-Mönch, D.; Hose, J.; Hrupec, D.; Huber, B.; Jogler, T.; Kellermann, H.; Klepser, S.; Krähenbühl, T.; Krause, J.; La Barbera, A.; Lelas, D.; Leonardo, E.; Lindfors, E.; Lombardi, S.; López, M.; López-Oramas, A.; Lorenz, E.; Makariev, M.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Miyamoto, H.; Moldón, J.; Moralejo, A.; Munar-Adrover, P.; Nieto, D.; Nilsson, K.; Orito, R.; Oya, I.; Paneque, D.; Paoletti, R.; Pardo, S.; Paredes, J. M.; Partini, S.; Pasanen, M.; Pauss, F.; Perez-Torres, M. A.; Persic, M.; Peruzzo, L.; Pilia, M.; Pochon, J.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reichardt, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rügamer, S.; Saggion, A.; Saito, K.; Saito, T. Y.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shayduk, M.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Spiro, S.; Stamatescu, V.; Stamerra, A.; Steinke, B.; Storz, J.; Strah, N.; Surić, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Tibolla, O.; Torres, D. F.; Treves, A.; Uellenbeck, M.; Vankov, H.; Vogler, P.; Wagner, R. M.; Weitzel, Q.; Zabalza, V.; Zandanel, F.; Zanin, R.; Kadenius, V.; Weidinger, M.; Buson, S.

    2012-03-01

    Aims: We study the non-thermal jet emission of the BL Lac object B3 2247+381 during a high optical state. Methods: 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. Results: The BL Lac object B3 2247+381 (z = 0.119) was detected, for the first time, 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. We model the spectral energy distribution using a one-zone SSC-model, which can successfully describe our data.

  4. Soft X-ray spectrum of BL Lacertae object AO 0235+164 as a tracer of elemental abundances at z approximately 0.5

    Science.gov (United States)

    Madejski, Greg

    1994-01-01

    We report the soft X-ray spectrum of BL Lac object AO 0235+164, observed with the Einstein Observatory Imaging Proportional Counter (IPC). This object (z = 0.94) has an intervening galaxy (or a protogalactic disk) at z = 0.524 present in the line of sight, producing both radio and optical absorption lines in the background BL Lac continuum. The X-ray spectrum exhibits a substantial soft X-ray cutoff, corresponding to several times that expected from our own Galaxy; we interpret that excess cutoff as due to the intervening galaxy. The comparison of the hydrogen column density inferred from the 21 cm radio data and the X-ray absorption allows, in principle, the determination of the elemental abundances in the intervening galaxy. However, the uncertainties in both the H I spin temperature and X-ray spectral parameters only loosely restrict these abundances to be 2 +/- 1 solar, which even at the lower limit appears higher than that inferred from studies of samples of optical absoprtion-line systems.

  5. Evolutionary behaviour of BL Lac objects

    OpenAIRE

    Beckmann, Volker

    1998-01-01

    We present analysis of a new flux limited sample of 72 X-ray selected BL Lacertae objects with known redshifts for 59 of them. We find the more X-ray dominated BL Lac having negative evolution with redshift, while intermediate objects show no evolution at all. X-ray dominated objects show higher X-ray luminosities and flatter X-ray spectra than the intermediate ones. We were also able to determine the redshift of 1517+656, which is part of our sample and is the optically most luminous X-ray s...

  6. The Optical Light curve of BL Lacertae during the 1997 outburst

    Science.gov (United States)

    Tosti, G.; Luciani, M.; Fiorucci, M.; Maesano, M.; Massaro, E.; Montagni, F.; Nesci, R.; Kurtanidze, O.; Nikolashvili, M.; Natriashvili, V.; Butikashvili, L.; Takalo, L. O.; Sillanpaä, A.; Katajainen, S.; Keinä Nen, P.; Nilsson, K.

    We report the data archive of the 1997 optical monitoring campaign on BL Lacertae carried out by the Perugia, Roma, Tuorla and Abarstumani groups. During this campaign BL Laceratae the showed an exceptional outburst, and in August 1997 the source reached the highest value ever recorded in the last 25 years.

  7. Analysis of the activity of the blazar BL Lacertae over the period 1998-2011

    Science.gov (United States)

    Strigunov, K. S.; Zhovtan, A. V.

    2016-07-01

    In 1998-2011 the blazar (active galactic nucleus) BL Lacertae was observed at Crimean Astrophysical Observatory (CrAO) with the second-generation GT-48 Cherenkov telescope at energies >1 TeV with a total significance of 11.8σ. More than 20 flares and a fourfold change in yearly mean fluxes (>1 TeV) were recorded. The optical ( B band) data obtained at CrAO and the TeV data are shown to correlate in some time intervals. The optical data are also compared with the X-ray RXTE/ASM (2-10 keV) data. In addition, the data from GT-48 are compared with the gamma-ray fluxes recorded by the Fermi LAT space telescope (0.1-300 GeV). The 2009 flare at TeV and Fermi energies has been studied. As a result, it has been found that as the activity rises the increase in flux at high energies exceeds its increase at low energies. This conclusion may be related to the conversion mechanism of particle acceleration. This is consistent with the results of studies for a similar object, 1ES 1426+428.

  8. Optical behaviour of BL Lacertae during the great 1997 outburst.

    Science.gov (United States)

    Tosti, G.; Luciani, M.; Fiorucci, M.; Massaro, E.; Nesci, R.; Maesano, M.; Montagni, F.; Villata, M.; Raiteri, C. M.; de Francesco, G.; Sobrito, G.; Takalo, L. O.; Sillanpää, A.; Katajainen, S.; Pursimo, T.; Kurtanidze, O. M.; Nikolashvili, M. G.

    The authors report here optical observations of BL Lac performed during its large outburst in 1997. During this monitoring the source reached the brightest magnitude observed in the last 25 years, showing a variability pattern characterized by rapid flares lasting from few hours to days.

  9. Parsec-scale jet precession in BL Lacertae (2200+420)

    CERN Document Server

    Caproni, Anderson; Monteiro, Hektor

    2012-01-01

    BL Lacertae is the prototype of the BL Lac class of active galactic nuclei, exhibiting intensive activity on parsec (pc) scales, such as intense core variability and multiple ejections of jet components. In particular, in previous works the existence of precession motions in the pc-scale jet of BL Lacertae has been suggested. In this work we revisit this issue, investigating temporal changes of the observed right ascension and declination offsets of the jet knots in terms of our relativistic jet-precession model. The seven free parameters of our precession model were optimized via a heuristic cross-entropy method, comparing the projected precession helix with the positions of the jet components on the plane of the sky and imposing constraints on their maximum and minimum superluminal velocities. Our optimized best model is compatible with a jet having a bulk velocity of 0.9824c, which is precessing with a period of about 12.1 yr in the observer's reference frame and changing its orientation in relation to the...

  10. Synchrotron and Compton Components and their Variability in BL Lac Objects

    OpenAIRE

    Giommi, P.; Ghisellini, G.; Padovani, P.; Tagliaferri, G.

    2000-01-01

    BL Lacertae objects are extreme extragalactic sources characterized by the emission of strong and rapidly variable nonthermal radiation over the entire electromagnetic spectrum. Synchrotron emission followed by inverse Compton scattering in a relativistic beaming scenario is generally thought to be the mechanism powering these objects. ...

  11. Imaging redshift estimates for Fermi BL Lac objects

    Energy Technology Data Exchange (ETDEWEB)

    Stadnik, Matt; Romani, Roger W., E-mail: mstadnik@stanford.edu, E-mail: rwr@astro.stanford.edu [Dept. of Physics/KIPAC, Stanford University, Stanford, CA 94305-4060 (United States)

    2014-04-01

    We have obtained WIYN and SOAR i' images of BL Lacertae objects and used these to detect or constrain the flux of the host galaxy. Under common standard candle assumptions, these data provide estimates of, or lower bounds on, the redshift. Our targets are a set of flat-spectrum radio counterparts of high flux Fermi Large Area Telescope sources, with sensitive spectral observations showing them to be continuum-dominated BL Lac objects. In this sample, 5 of 11 BL Lac objects yielded significant host detections, with standard candle redshifts z = 0.13-0.58. Our estimates and lower bounds are generally in agreement with other redshifts estimates, although our z = 0.374 estimate for J0543–5532 implies a significantly sub-luminous host.

  12. Is BL Lacertae an "orphan" AGN? Multiband and spectroscopic constraints on the parent population

    CERN Document Server

    Capetti, Alessandro; Buttiglione, Sara; ),

    2010-01-01

    We have analysed optical spectra of BL Lacertae, the prototype of its class, to verify the presence and possible flux variations of its broad Ha line. We used the spectroscopic information also to investigate the question of its parent population. Four spectra were acquired at the TNG in 2007-2008, when the source was in a relatively faint state. In three cases we were able to measure the broad Ha and several narrow emission lines. A comparison with previous results suggests that the broad Ha has increased by ~50% in ten years, a change not unusual for Broad Lined AGN. We estimated a black hole mass for BL Lac of 4-6 10^8 solar masses from its relation with the bulge luminosity. The virial mass estimated from the spectroscopic data is instead 20-30 times smaller. We suggest that this discrepancy is due to the BL Lac BLR being underluminous. Finally, we addressed the problem of the BL Lac parent population, comparing its isotropic quantities with those of other AGN classes. From the point of view of the narrow...

  13. Broad-Band Spectral Indices Variability of BL Lacertae by Wavelet Method

    Indian Academy of Sciences (India)

    Hao-Jing Zhang; Jing-Ming Bai; Yu-Ying Bao; Xiong Zhang

    2014-09-01

    BL Lacertae is one of the famous AGN that shows convincing evidence to support periodic variability. We compile R-band data and radio 22 GHz database from the available literature to build the light curves and to calculate broad-band spectral indices. This paper employs the wavelet periodic estimation method. The analysis results indicate that the most possible period is 7.02–7.36 yr in the selected wave-bands. The broad-band spectral indices have a possible period of 4.11 yr as a half value in selected wave-bands. The results confirm that the variability period in the radio 22 GHz is in agreement with the optical R band of about 7.01 yr, as also mentioned in other literatures.

  14. RAPID TeV GAMMA-RAY FLARING OF BL LACERTAE

    Energy Technology Data Exchange (ETDEWEB)

    Arlen, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Aune, T.; Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Cesarini, A.; Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Cui, W.; Feng, Q.; Finley, J. P. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Dumm, J.; Fortson, L. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Falcone, A. [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); Federici, S. [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Finnegan, G., E-mail: qfeng@purdue.edu, E-mail: cui@purdue.edu [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Collaboration: VERITAS Collaboration; and others

    2013-01-10

    We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6 minute exposure, when the integral flux above 200 GeV reached (3.4 {+-} 0.6) Multiplication-Sign 10{sup -6} photons m{sup -2} s{sup -1}, roughly 125% of the Crab Nebula flux measured by VERITAS. The light curve indicates that the observations missed the rising phase of the flare but covered a significant portion of the decaying phase. The exponential decay time was determined to be 13 {+-} 4 minutes, making it one of the most rapid gamma-ray flares seen from a TeV blazar. The gamma-ray spectrum of BL Lacertae during the flare was soft, with a photon index of 3.6 {+-} 0.4, which is in agreement with the measurement made previously by MAGIC in a lower flaring state. Contemporaneous radio observations of the source with the Very Long Baseline Array revealed the emergence of a new, superluminal component from the core around the time of the TeV gamma-ray flare, accompanied by changes in the optical polarization angle. Changes in flux also appear to have occurred at optical, UV, and GeV gamma-ray wavelengths at the time of the flare, although they are difficult to quantify precisely due to sparse coverage. A strong flare was seen at radio wavelengths roughly four months later, which might be related to the gamma-ray flaring activities. We discuss the implications of these multiwavelength results.

  15. A new three-stage evolution model for millimeter to centimeter wavelength outbursts in BL Lacertae

    International Nuclear Information System (INIS)

    The multi-frequency light curves of BL Lacertae during 1997.5-1999.5 have been modeled by four outbursts, each having a 3-stage evolution in the (Sm, vm) plane with distinct rising-plateau-decaying phases. It is shown that the observed light curves can be well fitted for the eight frequencies from 350 GHz to 4.8 GHz. The main characteristics of the model-fitting are: (1) the outbursts are found to have very flat spectra with an optically thin spectral index α (defined as Sv ∝ v-α) of about 0.15. This is consistent with the results previously obtained by Valtaoja et al. (1992); (2) it is found that there is no spectral flattening between the rising-plateau phase and the decay phase. In other words, the optically thin spectral index does not change from the rising-plateau phase to the decay phase. These features are in contrast to the 3-stage shocked-in-jet model proposed by Marscher and Gear (1985) for submm-IR-optical flares, in which a spectral flattening of Δα = 0.5 is predicted when a transition occurs from the Compton/synchrotron phase (or rising-plateau phase) to the adiabatic phase (or decay phase) with α ∼> 0.5 for the shock being non-radiative. We propose a new model to interpret the fitting results, suggesting that the 3-stage evolution of the mm-cm outbursts in BL Lacertae may be related to the process of shock formation and propagation in a highly collimated jet (for example, a 'parabolic' jet). In particular, during the rising phase, the thickness of the synchrotron-radiating region created by the shock may rapidly increase with time (relative to the jet width) due to the rapid injection of relativistic electrons and a magnetic field, and this leads to the observed behavior that the turnover flux density Sm rapidly increases while the turnover frequency vm decreases. In the decay phase, the emitting plasma enters into a free expansion regime without further injection of relativistic electrons and a magnetic field (for example, when a transition

  16. The awakening of BL Lacertae: observations by Fermi, Swift, and the GASP-WEBT

    CERN Document Server

    Raiteri, C M; D'Ammando, F; Larionov, V M; Gurwell, M A; Mirzaqulov, D O; Smith, P S

    2013-01-01

    Since the launch of the Fermi satellite, BL Lacertae has been moderately active at gamma-rays and optical frequencies until May 2011, when the source started a series of strong flares. The exceptional optical sampling achieved by the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) in collaboration with the Steward Observatory allows us to perform a detailed comparison with the daily gamma-ray observations by Fermi. Discrete correlation analysis between the optical and gamma-ray emission reveals correlation with a time lag of 0 +- 1 d, which suggests cospatiality of the corresponding jet emitting regions. A better definition of the time lag is hindered by the daily gaps in the sampling of the extremely fast flux variations. In general, optical flares present more structure and develop on longer time scales than corresponding gamma-ray flares. Observations at X-rays and at millimetre wavelengths reveal a common trend, which suggests that the region producing the mm and X-ray radiat...

  17. BL Lacertae:Hard Optical Spectrum and GeV γ-ray Emission

    Institute of Scientific and Technical Information of China (English)

    Shan-Jie Qian; Xi-Zhen Zhang; T.P.Krichbaum

    2004-01-01

    The spectral energy distribution(SED)of the γ-ray flare observed in July 1997 in BL Lacertae is re-considered.It is pointed out that the optical observations made by Webb et al.showed the associated optical flare has a hard spectrum(the average spectral index αopt ~ 0.48,Fv ∝ v-α),and the ASCA observations made by Tanihata et al.showed very steep spectra in the soft X-ray band(0.7-1.5 keV)(αx~3-4).We find that the flux densities and spectral indices in both the spectrum emitted by relativistic electrons of a power-law energy distribution with a high energy cutoff,and thus the peak of the SED of the synchrotron radiation(in representation of vFv)is located in the EUV-soft X-ray bands.Therefore,the GeV γ-ray emission observed in the July 1997 outburst may be mainly due to the synchrotron self-Compton(SSC)process,contrasting with the current explanations in terms of external radiation Compton(ERC)process,in which the seed photons are mostly taken to be the UV emission from the clouds of the broad emission line region.We argue that the hard optical spectra observed during the γ-ray outburst may be an important signature for the acceleration of high energy electrons(γe~104)in the γ-ray emitting region.

  18. The long-term Swift observations of the high-energy peaked BL Lacertae source 1ES 1959+650

    Science.gov (United States)

    Kapanadze, B.; Romano, P.; Vercellone, S.; Kapanadze, S.; Mdzinarishvili, T.; Kharshiladze, G.

    2016-03-01

    We present the results based on the monitoring of the high-energy peaked BL Lacertae object 1ES 1959+650 by the Swift satellite during 2005-2014. Our timing study shows that the source was highly variable on longer (weeks-to-months) time-scales with the 0.3-10 keV fluxes ranging by a factor of 8. It sometimes showed a significant intra-day variability in the course of ˜1 ks, detected mainly in the epochs of higher brightness states. The flux variability exhibited an erratic character and no signatures of periodic variations are revealed. The X-ray spectra were mainly curved with broad ranges of photon index, curvature parameter, hardness ratio, synchrotron spectral energy distribution (SED) peak location which exhibited a significant variability with the flux at different time-scales. Our study of multi-wavelength cross-correlations shows that the one-zone synchrotron self-Compton scenario was not always valid for 1ES 1959+650. The X-ray flares were sometimes not accompanied with an increasing activity in the γ-ray or lower-energy parts of the spectrum and vice versa. Similar to the prominent `orphan' TeV event in 2002, significant flares in the high-energy and very high energy bands in 2009 May and 2012 May were not accompanied by those in the synchrotron part of the spectrum. Similar to other TeV-detected high-energy peaked BLLs, the stochastic acceleration of the electrons from the magnetic turbulence close to the shock front may be more important for our target compared to other scenarios since it showed mainly broader synchrotron SEDs during the X-ray flares expected when the stochastic mechanism is more efficient.

  19. BL Lacertae complex spectral variability and rapid synchrotron flare detected with BeppoSAX

    CERN Document Server

    Ravasio, M; Ghisellini, G; Giommi, P; Nesci, R; Massaro, E; Chiappetti, L; Celotti, A; Costamante, L; Maraschi, L; Tavecchio, F; Tosti, G; Treves, A; Wolter, A; Balonek, T; Carini, M; Kato, T; Kurtanidze, O M; Montagni, F; Nikolashvili, M M; Noble, J; Nucciarelli, G; Raiteri, C M; Sclavi, S; Uemura, M; Villata, M

    2002-01-01

    We report on two BeppoSAX observations of BL Lac (2200+420) performed respectively in June and December 1999, as part of a ToO program to monitor blazars in high states of activity. During both runs the source has been detected up to 100 keV, but it showed quite different spectra: in June it was concave with a very hard component above 5-6 keV (alpha_1 ~ 1.6; alpha_2 ~ 0.15); in December it was well fitted by a single power law (alpha ~ 0.6). During the first BeppoSAX observation BL Lac showed an astonishing variability episode: the 0.3 - 2 keV flux doubled in ~ 20 minutes, while the flux above 4 keV was almost constant. This frequency-dependent event is one of the shortest ever recordered for BL Lac objects and places lower limits on the dimension and the magnetic field of the emitting region and on the energy of the synchrotron radiating electrons. A similar but less extreme behaviour is detected also in optical light curves, that display non-simultaneous, smaller fluctuations of ~ 20% in 20 min. We fit the...

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

    CERN Document Server

    Abdo, A A

    2011-01-01

    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 (Metsahovi 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. Moderate 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 component 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 averag...

  1. THE FIRST FERMI MULTIFREQUENCY CAMPAIGN ON BL LACERTAE: CHARACTERIZING THE LOW-ACTIVITY STATE OF THE EPONYMOUS BLAZAR

    International Nuclear Information System (INIS)

    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 (Metsaehovi 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. Moderate 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.

  2. VHE Analyses of Long-Term Low-Flux-State Observations by VERITAS of Intermediate-Frequency-Peaked BL Lacertae Sources: 3C 66A and W Comae

    CERN Document Server

    ,

    2015-01-01

    Intermediate-frequency-peaked BL Lacertae objects (IBLs) are a class of blazars characterized by a spectral energy distribution (SED) with a lower-energy synchrotron peak than the majority of extragalactic sources detected by ground-based imaging atmospheric Cherenkov telescopes (IACTs). Consequently, the peak gamma-ray flux falls outside the very-high-energy regime (VHE, >100 GeV) covered by IACTs such as VERITAS, making IBLs difficult to detect except during infrequent episodes of elevated flux. However, the study of these sources in a low-flux state is essential for developing a complete understanding of the blazar paradigm. We present the results of VHE analyses of long-term low-flux-state observations completed for two IBL sources: 3C 66A and W Comae. For both sources, data from VERITAS were analyzed for the VHE regime. The study of 3C 66A extends from 2007 to 2015, resulting in a 12 standard deviation ($\\sigma$) detection from $\\sim$61 observing hours. Analysis of W Comae from 2010 to 2014, totaling $\\s...

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

    Science.gov (United States)

    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.

  4. Probing the innermost regions of AGN jets and their magnetic fields with RadioAstron. I. Imaging BL Lacertae at 21 microarcsecond resolution

    CERN Document Server

    Gómez, José L; 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

    2016-01-01

    We present the first polarimetric space 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 within 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's diameters in length, allowing us to image the jet in BL Lacertae with a maximum angular resolution of 21 $\\mu$as, 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 $\\mu$as from the jet apex, in a pattern that includes other recollimation shocks at approximately 100 $\\mu$as and 250 $\\mu$as 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 analy...

  5. Studies of the Jet in BL Lacertae. II. Superluminal Alfv\\'en Waves

    CERN Document Server

    Cohen, M H; Arshakian, T G; Clausen-Brown, E; Homan, D C; Hovatta, T; Kovalev, Y Y; Lister, M L; Pushkarev, A B; Richards, J L; Savolainen, T

    2014-01-01

    Ridge lines on the pc-scale jet of the active galactic nucleus BL Lac display transverse patterns that move superluminally downstream. The patterns are not ballistic, but are analogous to waves on a whip. Their apparent speeds $\\beta_\\mathrm{app}$ (units of $c$) range from 4.2 to 13.5, corresponding to $\\beta_\\mathrm{wave}^\\mathrm{gal}= 0.981 - 0.998$ in the galaxy frame. We show that the magnetic field in the jet is well-ordered with a strong transverse component, and assume that it is helical and that the transverse patterns are longitudinal Alfv\\'en waves. The wave-induced transverse speed of the jet is non-relativistic ($\\beta_\\mathrm{tr}^\\mathrm{gal}\\sim 0.09$) and in agreement with our assumption of low-amplitude waves. In 2010 the wave activity subsided and the jet displayed a mild wiggle that had a complex oscillatory behavior. The waves are excited by changes in the position angle of the recollimation shock, in analogy to exciting a wave on a whip by shaking it. Simple models of the system are presen...

  6. Another look at the BL Lacertae flux and spectral variability. Observations by GASP-WEBT, XMM-Newton, and Swift in 2008-2009

    Science.gov (United States)

    Raiteri, C. M.; Villata, M.; Bruschini, L.; Capetti, A.; Kurtanidze, O. M.; Larionov, V. M.; Romano, P.; Vercellone, S.; Agudo, I.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Bach, U.; Berdyugin, A.; Blinov, D. A.; Böttcher, M.; Buemi, C. S.; Calcidese, P.; Carosati, D.; Casas, R.; Chen, W.-P.; Coloma, J.; Diltz, C.; di Paola, A.; Dolci, M.; Efimova, N. V.; Forné, E.; Gómez, J. L.; Gurwell, M. A.; Hakola, A.; Hovatta, T.; Hsiao, H. Y.; Jordan, B.; Jorstad, S. G.; Koptelova, E.; Kurtanidze, S. O.; Lähteenmäki, A.; Larionova, E. G.; Leto, P.; Lindfors, E.; Ligustri, R.; Marscher, A. P.; Morozova, D. A.; Nikolashvili, M. G.; Nilsson, K.; Ros, J. A.; Roustazadeh, P.; Sadun, A. C.; Sillanpää, A.; Sainio, J.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Troitsky, I. S.; Umana, G.

    2010-12-01

    Aims: In a previous study we suggested that the broad-band emission and variability properties of BL Lacertae can be accounted for by a double synchrotron emission component with related inverse-Compton emission from the jet, plus thermal radiation from the accretion disc. Here we investigate the matter with further data extending over a wider energy range. Methods: The GLAST-AGILE Support Program (GASP) of the whole earth blazar telescope (WEBT) monitored BL Lacertae in 2008-2009 at radio, near-IR, and optical frequencies to follow its flux behaviour. During this period, high-energy observations were performed by XMM-Newton, Swift, and Fermi. We analyse these data with particular attention to the calibration of Swift UV data, and apply a helical jet model to interpret the source broad-band variability. Results: The GASP-WEBT observations show an optical flare in 2008 February-March, and oscillations of several tenths of mag on a few-day time scale afterwards. The radio flux is only mildly variable. The UV data from both XMM-Newton and Swift seem to confirm a UV excess that is likely caused by thermal emission from the accretion disc. The X-ray data from XMM-Newton indicate a strongly concave spectrum, as well as moderate (~4-7%) flux variability on an hour time scale. The Swift X-ray data reveal fast (interday) flux changes, not correlated with those observed at lower energies. We compare the spectral energy distribution (SED) corresponding to the 2008 low-brightness state, which was characterised by a synchrotron dominance, to the 1997 outburst state, where the inverse-Compton emission was prevailing. A fit with an inhomogeneous helical jet model suggests that two synchrotron components are at work with their self inverse-Compton emission. Most likely, they represent the radiation from two distinct emitting regions in the jet. We show that the difference between the source SEDs in 2008 and 1997 can be explained in terms of pure geometrical variations. The

  7. Observation of X-Ray Variability in the BL Lac Object 1ES1959+65

    International Nuclear Information System (INIS)

    This paper reports X-ray spectral observations of a relatively nearby (z = 0.048) BL Lacertae (BL Lac) object 1ES1959+65, which is a potential TeV emitter. The observations include 31 short pointings made by the Unconventional Stellar Aspect (USA) Experiment on board the Advanced Research and Global Observation Satellite (ARGOS), and 17 pointings by the PCA on board the Rossi X-ray Timing Explorer (RXTE). Most of these observations were spaced by less than 1 day. 1ES1959+65 was detected by the ARGOS USA detector in the range 1-16 keV, and by the PCA in the 2-16 keV range but at different times. During the closely spaced RXTE observations beginning on 2000 July 28, an ending of one flare and a start of another are visible, associated with spectral changes, where the photon index Λ ranges between ∼ 1.4 and 1.7, and the spectrum is harder when the source is brighter. This implies that 1ES1959+65 is an XBL-type blazar, with the X-ray emission likely to originate via the synchrotron process. The USA observations reveal another flare that peaked on 2000 November 14 and doubled the flux within a few days, again associated with spectral changes of the same form. The spectral variability correlated with the flux and timing characteristics of this object that are similar to those of other nearby BL Lacs, and suggest relativistic beaming with a Doppler factor (delta) (ge) 1.6 and magnetic fields of the order of a few mG. We also suggest that the steady component of the X-ray emission--present in this object as well as in other XBLs--may be due to the large-scale relativistic jet (such as measured by Chandra in many radio-loud AGN), but pointing very closely to our line of sight

  8. New extreme synchrotron BL Lac objects

    International Nuclear Information System (INIS)

    We report on the BeppoSAX observations of four 'extreme' BL Lacs, selected to have high synchrotron peak frequencies. All have been detected also in the PDS band. For 1ES 0120+340, PKS 0548-322 and H 2356-309 the spectrum is well fitted by a convex broken power-law, thus locating the synchrotron peak around 1-4 keV. 1ES 1426+428 presents a flat energy spectral index (αx=0.92) up to ∼100 keV, thus constraining the synchrotron peak to lie near or above that value. For their extreme properties, all sources could be strong TeV emitters

  9. Radio Detection of 18 RASS BL Lac Objects

    Directory of Open Access Journals (Sweden)

    Anderson M. W. B.

    2009-12-01

    Full Text Available We present the radio detection of 18 BL Lac objects from oursurvey of over 575 deg$^2$ of sky. These 18 objects are located within$20arcsec$ of the X-ray position, of which 11 have a measuredred-shift. All candidates are radio emitters above $sim$1 mJy and fall within the range of existing samples on the two colour, $alpha _mathrm{RO}$ vs $alpha _mathrm{OX}$, diagram with a transitional population of three evident. Two unusual sources have been identified, a candidate radio quiet BL Lac, RX J0140.9-4130, and an extreme HBL, RX J0109.9-4020, with $log( u _mathrm{peak}approx 19.2$. The BL Lac $log(N-log(S$ relation is consistent with other samples and indicates the ROSAT All Sky Survey (RASS could contain ($2000{pm}400$ BL Lac objects.

  10. Radio-loud Active Galaxies in the Northern ROSAT All-Sky Survey. III. New Spectroscopic Identifications from the RASS endash Green Bank BL Lacertae Survey

    International Nuclear Information System (INIS)

    We present new spectroscopic identifications for 169 objects in the RASS endash Green Bank (RGB) catalog of radio- and X-ray endash emitting active galactic nuclei (AGNs). The data presented here significantly increase the fraction of bright RGB objects with classifications. Specifically, we report and discuss the classification of 57 radio-loud quasars, eight radio-quiet quasars (QSOs), 53 BL Lacs, 32 broad-line radio galaxies, five narrow-line radio galaxies, three Seyfert I galaxies, and 11 galaxies or galaxies in clusters. Over 78% of the identifications we present here are the first published classifications for these sources. The observations we report were undertaken as part of our targeted search program to identify a new, large unbiased sample of BL Lac objects, and we therefore discuss the BL Lac sample extensively. Unlike many previous surveys, we impose no selection criteria based on optical morphology, color, or broadband spectral energy distribution. Our classifications are based solely on a carefully defined set of self-consistent spectroscopic classification criteria. These criteria are then carefully evaluated, and particular attention is paid to issues involving the classification and description of BL Lacs. The criteria yielded BL Lac classifications for 53 RGB objects, 38 of which were are newly discovered BL Lacs. We show these RGB BL Lacs exhibit transitional properties between normal galaxies and BL Lacs discovered in previous radio and X-ray surveys. We briefly discuss the broadband flux distributions of these new RGB BL Lacs and the range of Ca ii H and K break contrasts (Br4000) they exhibit. We show that there is no clear separation in Br4000 between BL Lacs and galaxies detected in the RGB survey, with the distribution of break strengths varying smoothly between 0% and 50%. We also present and use a simple method based on the break strength to estimate the contribution of both the host galaxy and AGN to the 4000 Angstrom flux. We also

  11. The fraction of BL Lac objects in groups of galaxies

    CERN Document Server

    Muriel, Hernán

    2016-01-01

    Context: BL Lac objects are a rare class of active galactic nuclei that typically show featureless optical spectra that make it difficult to estimate the redshift. A novel method for estimating the redshift of BL Lac objects has recently been proposed which assumes that these objects typically reside in groups of galaxies. Aims: The aim of this work is to estimate the fraction of BL Lac objects that reside in groups of galaxies. Methods: We use a sample of groups (M12 catalogue) selected by applying a friends-of-friends algorithm in the SDSS DR12. Galaxies in the M12 sample were cross-correlated with the sample of blazars in the BZCAT. Results: We found that 121 galaxies in the M12 catalogue are blazars in the BZCAT sample, all but one are BL Lac objects, and a large fraction are classified as BL Lac-galaxy dominated. Analysing the fraction of galaxies in groups as a function of redshift we have estimated a correction factor that takes into account the typical incompleteness of the catalogues based on the fri...

  12. HESS J1943+213: a candidate extreme BL Lacertae object

    CERN Document Server

    Abramowski, A; Aharonian, F; Akhperjanian, A G; Anton, G; Balzer, A; Barnacka, A; de Almeida, U Barres; Bazer-Bachi, A R; Becherini, Y; Becker, J; Behera, B; Bernlöhr, K; Bochow, A; Boisson, C; Bolmont, J; Bordas, P; Borrel, V; 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; Chounet, L -M; Clapson, A C; Coignet, G; Colom, P; 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; Dubois, F; Dubus, G; Dyks, J; Dyrda, M; Egberts, K; Eger, P; Espigat, P; Fallon, L; Farnier, C; Fegan, S; Feinstein, F; Fernandes, M V; Fiasson, A; Fontaine, G; Förster, A; Fü\\ssling, M; Gallant, Y A; Gast, H; Gérard, L; Gerbig, D; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Göring, D; Häffner, S; Hague, J D; Hampf, D; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, 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; Khangulyan, D; Khélifi, B; Klochkov, D; Kluźniak, W; Kneiske, T; Komin, Nu; Kosack, K; Kossakowski, R; Laffon, H; Lamanna, G; Lennarz, D; Lohse, T; Lopatin, A; Lu, C -C; Marandon, V; Marcowith, A; Masbou, J; Maurin, D; Maxted, N; McComb, T J L; Medina, M C; Méhault, J; Nguyen, N; Moderski, R; Moulin, E; Naumann, C L; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Nicholas, B; Niemiec, J; Nolan, S J; Ohm, S; Olive, J-F; Wilhelmi, E de Oña; Opitz, B; Ostrowski, M; Panter, M; Arribas, M Paz; Pedaletti, G; Pelletier, G; Petrucci, P -O; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raue, M; Rayner, S M; Reimer, A; Reimer, O; Renaud, M; Reyes, R de los; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Ruppel, J; Ryde, F; Sahakian, V; Santangelo, A; Schlickeiser, R; Schöck, F M; Schönwald, A; Schulz, A; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Sikora, M; Skilton, J L; Sol, H; Spengler, G; Stawarz, \\L; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Szostek, A; Tavernet, J -P; Terrier, R; Tibolla, O; Tluczykont, M; Valerius, K; van Eldik, C; Vasileiadis, G; Venter, C; Vialle, J P; Viana, A; Vincent, P; Vivier, M; Völk, H J; Volpe, F; Vorobiov, S; Vorster, M; Wagner, S J; Ward, M; Wierzcholska, A; Zajczyk, A; Zdziarski, A A; Zech, A; Zechlin, H -S; Burnett, T H; Hill, A B

    2011-01-01

    We report on a newly detected point-like source, HESS J1943+213 located in the Galactic plane. This source coincides with an unidentified hard X-ray source IGR J19443+2117, which was proposed to have radio and infrared counterparts. HESS J1943+213 is detected at the significance level of 7.9 \\sigma (post-trials) at RA(J2000)=19h 43m 55s +- 1s (stat) +- 1s (sys), DEC(J2000) = +21deg 18' 8" +- 17" (stat) +- 20" (sys). The source has a soft spectrum with photon index Gamma = 3.1 +- 0.3 (stat) +- 0.2 (sys) and a flux above 470 GeV of 1.3 +- 0.2 (stat) +- 0.3 (sys) x 10^{-12} cm^{-2} s^{-1}. There is no Fermi/LAT counterpart down to a flux limit of 6 x 10^{-9} cm^{-2} s^{-1} in the 0.1-100 GeV energy range (95% confidence upper limit calculated for an assumed power-law model with a photon index Gamma=2.0). The data from radio to VHE gamma-rays do not show any significant variability. We combine new H.E.S.S., Fermi/LAT and Nancay Radio Telescope observations with pre-existing non-simultaneous multi-wavelength obser...

  13. Diffuse γ-ray emission from unresolved BL Lac objects

    International Nuclear Information System (INIS)

    Blazars, active galactic nuclei with a jet pointing toward the Earth, represent the most abundant class of high-energy extragalactic γ-ray sources. The subset of blazars known as BL Lac objects is on average closer to Earth (i.e., younger) and characterized by harder spectra at high energy than the whole sample. The fraction of BL Lacs that is too dim to be detected and resolved by current γ-ray telescopes is therefore expected to contribute to the high-energy isotropic diffuse γ-ray background (IGRB). The IGRB has been recently measured over a wide energy range by the Large Area Telescope (LAT) on board the Gamma-ray Space Telescope (Fermi). We present a new prediction of the diffuse γ-ray flux due to the unresolved BL Lac blazar population. The model is built upon the spectral energy distribution and the luminosity function derived from the fraction of BL Lacs detected (and spectrally characterized) in the γ-ray energy range. We focus our attention on the O(100) GeV energy range, predicting the emission up to the TeV scale and taking into account the absorption on the extragalactic background light. In order to better shape the BL Lac spectral energy distribution, we combine the Fermi-LAT data with Imaging Atmospheric Cerenkov Telescope measurements of the most energetic sources. Our analysis is carried on separately for low- and intermediate-synchrotron-peaked BL Lacs on the one hand and high-synchrotron-peaked BL Lacs on the other hand: we find in fact statistically different features for the two. The diffuse emission from the sum of both BL Lac classes increases from about 10% of the measured IGRB at 100 MeV to ∼100% of the data level at 100 GeV. At energies greater than 100 GeV, our predictions naturally explain the IGRB data, accommodating their softening with increasing energy. Uncertainties are estimated to be within of a factor of two of the best-fit flux up to 500 GeV.

  14. Optical polarization of high-energy BL Lac objects

    CERN Document Server

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

    2016-01-01

    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. We wish to understand if there are differences in the BL Lac objects that are detected with the current-generation TeV instruments compared to those that have not yet been detected. 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 seems t...

  15. BL Lac Objects and Blazars Past, Present, and Future

    CERN Document Server

    Urry, C M

    1998-01-01

    The past 20 years have seen phenomenal progress in our understanding of BL Lac objects. They form part of the blazar class, which are radio-loud AGN whose relativistic jets are aligned along our line of sight. Several critical milestones have helped establish this picture, first proposed at the Pittsburgh BL Lac meeting 20 years ago, most recently the EGRET and TeV detections of beamed gamma-ray emission. The spectral energy distributions are double peaked and follow a self-similar sequence in luminosity, which can be explained by electron cooling on ambient photons. This simple paradigm has yet to be tested, and further questions remain, notably about physical conditions in blazar jets --- the kinetic power, magnetic energy density, acceleration time scales, proton content, etc. --- and how this energy is transported in the innermost regions. Some clues are available from multiwavelength monitoring campaigns although better sampling over longer periods is clearly called for. Recent work on the host galaxies ...

  16. Very high-resolution observations of the radio sources NRAO 150, OJ 287, 3C 273, M87, 1633+38, BL Lacertae, and 3C 454. 3

    Energy Technology Data Exchange (ETDEWEB)

    Kellermann, K.I. (National Radio Astronomy Observatory, Green Bank, WV); Shaffer, D.B.; Purcell, G.H.

    1977-02-01

    Very long baseline interferometer observations made at a wavelength of 2 and 2.8 cm with baselines ranging from 54 to 291 million wavelengths show a number of radio sources with only slightly resolved components, even on the longest baselines; the quasars 1633 + 38 and 3C 454.3, the objects OJ 287 and BL Lac, and the nucleus of M87 (Virgo A, 3C 274) all contain components < or approximately 0.4 milli-arcsec. The smallest component observed is in the core of 3C 454.3, which contains about 50% of the total flux density and is < or approximately 0.2 milli-arcsec in diameter. The compact component in the nucleus of M87 is < or approximately 1.5 light-months across, and contains about one-third of the total flux density of the nucleus at 2.8 cm. NRAO 150 and BL Lac are double: the components of NRAO 150 are separated by 0.6 milli-arcsec, while BL Lac has an elongated structure consisting of a large (1.4 milli-arcsec) component separated by 1.25 milli-arcsec from a smaller (0.5 milli-arcsec) variable one. The present data on 3C 273 are consistent with triple models similar to those discussed previously, but with a somewhat greater apparent separation of components.

  17. Absorption in the spectra of quasi stellar objects and BL Lac objects

    International Nuclear Information System (INIS)

    An extensive review is given of the observations of absorption in the spectra of QSOs and BL Lac objects. In Table Ia we summarize all of the information available up to May 1, 1978 on objects which show absorption. Following discussion of the observations in Section II, possible interpretations are critically discussed. (orig.)

  18. Extraordinary Activity in the BL Lac Object OJ~287

    CERN Document Server

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

    1998-01-01

    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 UMRAO variability program. We find clear evidence for a persistent modulation of the total flux and polarization with period $\\sim 1.66$ years, and for another signal that dominates activity in the 1980s with period $\\sim 1.12$ years. The relationship between these two variations can be understood in terms of a `shock-in-jet' model, in which the longer time scale periodicity is associated with an otherwise quiescent jet, and the shorter time scale 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...

  19. Broad band energy distribution of UV-bright BL Lac objects

    International Nuclear Information System (INIS)

    IUE satellite data in the 1200-2000 and 1900-3200 A intervals of BL Lac objects are analyzed in terms of two discernible groups. A total of 25 BL Lac objects were observed, with differences between groups displayed in terms of the power slope of the energy of the UV emissions, i.e., slopes of 1 and 2. Comparisons of the spectra with those of quasars showed that quasars have a small spectral index in the 1000-6000 A band and no correlation exists between the spectral index and UV flux of the BL Lac objects. The comparisons underscore the lack of a thermal component for BL Lac objects. Steep spectral components in both BL Lac objects and highly polarized quasars emissions could both be due to synchrotron emission. Compton scattering of relativistic electrons off synchrotron photons could produce the X ray emissions. 44 references

  20. A comparison of some radio and optical properties of quasi-stellar sources and BL Lacertae objects

    International Nuclear Information System (INIS)

    An empirical relation between radio spectral index and amplitude of optical variability for quasi-stellar sources with continuous, featureless optical spectra (QC sources) is extended to include sources with optical spectral lines. The radio spectral index at 5 GHz is found to correlate with the ratio of radio to optical luminosity in a clear-cut fashion when optical and radio variability is taken into account. QC sources are found to represent a tightly knit group vis-a-vis the general population. The predictive capabilities of the correlations are discussed. The properties of the weak-line N galaxy 3C 371 are very similar to those of the QC source population. When optical variability is taken into account, the Hubble diagram provides further evidence for a cosmological interpretation of redshift

  1. Are some BL Lacs artefacts of gravitational lensing?

    International Nuclear Information System (INIS)

    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. This hypothesis was made on the basis of certain general similarities between BL Lacs and OVVs, but for two recently observed BL Lacs 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. (author)

  2. Gamma-ray Emission from the γ-ray-loud BL Lac Objects

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using the HST observation data of BL Lac objects by Urry et al. and γγ-ray observation data, we find that there is a correlation between Fγ and FO nucleifor γ-ray-loud BL Lac objects (correlation coefficients: γ = 0.63,p = 4.0 × 10-2),but no correlation between Fγ and Fohost, where FO nuclei and Fohost are the fluxes ofnuclei and host galaxy in V-band. For 19 γ-ray-loud BL Lac objects with observedspectral index in multi-wavebands, the spectral index correlations between any twobands are as follow: (1) there is a strong correlation between αγ and αK for 15 BLLac objects(γ = 0.84,p = 3.11 × 10-4); (2) the correlation between αγ and αo for12 BL Lac objects is γ = 0.82,p = 1.5 × 10-3; (3) there is no correlation betweenαγ and αx for 16 BL Lac objects. The results, together with characteristic double-humped shape of their SEDs, show that the synchrotron self-Compton mechanismmight be a main mechanism for the γ-ray emission of the BL Lac objects. Theelectrons emitting IR and optical radiation via synchrotron are also responsible forupscattering these photons to γ-rays, and a variability in IR-optical regime shouldbe accompanied by a change in the γ-rays.

  3. Multiband optical polarimetry of BL Lac objects with the Nordic Optical Telescope

    CERN Document Server

    Tommasi, L; Pian, E; Piirola, V; Poretti, E; Scaltriti, F; Sillanpää, A; Takalo, L; Treves, A

    2001-01-01

    Optical polarization of seven selected BL Lac objects in UBVRI bands was studied with the Nordic Optical Telescope from December 10-14, 1999. Two of them, 3C 66A and PKS 0735+178, were monitored for 4 nights for a total integration time of 4.75 and 5.5 hours, respectively. Other objects (1Jy 0138-097, H 0414+009, PKS 0823-223, OJ287 and BL Lac) were observed sparsely during the run. Apart from PKS 0823-223 (more polarized than observed in the past), the sources show levels of flux and polarization consistent with results at previous epochs. 3C 66A and PKS 0735+178 were intensively observed during December 11 and 12 and exhibited variability of polarization, both on internight and intranight time scales. Wavelength dependence of polarization has been investigated, as well as circular polarization. The results are discussed within the standard model for BL Lacs.

  4. Multi-wavelength studies of TeV γ-ray emitting BL Lac objects

    International Nuclear Information System (INIS)

    The discovery of TeV γ-ray emission of BL Lac objects gave new insights in the particle acceleration and the emission processes of the highly relativistic jets. To shed light on the conditions in the high energetic jets of the TeV γ-ray emitting BL Lac objects, I have studied in great detail the spectral energy distribution (SED) of sources with different characteristics. BL Lac objects with exceptional very high energy spectra (soft and hard spectra) and with large differences in the emission peak frequencies, to cover the different classes of BL Lac objects, have been chosen. The basic aim of this thesis was, to study with new, simultaneous multi- avelength (MWL) observations, if the emission processes of these extreme cases of TeV BL Lac objects can be explained by the synchrotron Self-Compton (SSC) model which is well established for the class of BL Lac objects at lower energies. We proposed MWL observations in the optical, UV and X-ray regime, to be conducted simultaneous to very high energy observations with the H.E.S.S. experiment, to study the emission processes. Simultaneous observations are crucial, since BL Lac objects are variable at all wavebands. I have analysed the MWL observations and conducted detailed variability and spectral studies in each wavelength range. The different kind of absorption at each wavelength as well as the influence of the host galaxy of the AGN has been considered to obtain the intrinsic jet spectrum. I have then applied the commonly used theoretical jet model, the SSC model, to the SED. I conducted a MWL campaign on a BL Lac object with the softest TeV spectrum, PKS 2005-489, during which it was observed in a very bright X-ray state. The good spectral coverage of the emission peaks allowed a detailed study of the SSC model. The extreme BL Lac object 1ES 0229+200 exhibits a hard intrinsic TeV spectrum. With my MWL campaign I found a clear cut-off in the optical range and therefore a high minimum Lorentz factor is needed to

  5. Statistical analysis of optical variability in the Perugia monitoring sample of BL Lac objects.

    Science.gov (United States)

    Fiorucci, M.; Tosti, G.; Luciani, M.

    The authors present a statistical analysis of optical variability in a sample of 25 BL Lac objects observed at the Perugia University Observatory in the last years. The light curves did not show clear periodic behaviors and are a combination of flicker and shot noise.

  6. Dynamical black hole masses of BL Lac objects from the Sloan Digital Sky Survey

    NARCIS (Netherlands)

    R.M. Plotkin; S. Markoff; S.C. Trager; S.F. Anderson

    2011-01-01

    We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey with redshifts out to z∼ 0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black hole mass -

  7. Dynamical black hole masses of BL Lac objects from the Sloan Digital Sky Survey

    NARCIS (Netherlands)

    Plotkin, R. M.; Markoff, S.; Trager, S. C.; Anderson, S. F.

    2011-01-01

    We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey with redshifts out to z similar to 0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black h

  8. Dynamical Black Hole Masses of BL Lac Objects from the Sloan Digital Sky Survey

    NARCIS (Netherlands)

    Plotkin, Richard M.; Markoff, Sera; Trager, Scott C.; Anderson, Scott F.

    2012-01-01

    We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey (SDSS) with redshifts out to z ∼ 0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black hol

  9. Optical spectroscopy of SDSS J004054.65-0915268: three possible scenarios for the classification. A z \\sim 5 BL Lacertae, blue FSRQ or a weak emission line quasar

    CERN Document Server

    Landoni, M; Bianco, A; Tavecchio, F; Bonnoli, G; Ghisellini, G

    2015-01-01

    The haunt of high redshift BL Lacerate objects is day by day more compelling, to firmly understand their intrinsic nature and evolution. SDSS J004054.65-0915268 is, at the moment, one of the most distant BL Lac candidate at z \\sim 5 (Plotkin et al 2010). We present a new optical-near IR spectrum obtained with ALFOSC-NOT with a new, custom designed dispersive grating aimed to detect broad emission lines that could disprove this classification. In the obtained spectra we do not detect any emission features and we provide an upper limit to the luminosity of the C IV broad emission line. Therefore, the nature of the object is then discussed, building the overall spectral energy distribution and fitting it with three different models. Our fits, based on the SED modeling with different possible scenarios, cannot rule out the possibility that this source is indeed a BL Lac object although, the absence of optical variability and lack of strong radio flux, they seems to suggest that the observed optical emission origi...

  10. BeppoSAX Spectral Survey of BL Lacs - new spectra and results

    OpenAIRE

    Beckmann, V.; Wolter, A.; Celotti, A.; Costamante, L.; Ghisellini, G.; Maccacaro, T.; Tagliaferri, G.

    2001-01-01

    We present BeppoSAX LECS, MECS, and PDS spectra of eleven X-ray selected BL Lacertae objects. Combining these sources with the ones presented elsewhere we have a sample of 21 BL Lacs from the Einstein Medium Sensitivity and Einstein Slew Survey. The sample shows strong correlations of several physical parameters with the peak frequency of the synchrotron branch of the spectral energy distribution. In particular the peak frequency is correlated to the X-ray spectral shape: objects with the pea...

  11. The colours of BL Lac objects: a new approach to their classification

    CERN Document Server

    Massaro, Enrico; Piranomonte, Silvia

    2012-01-01

    We selected a sample of 437 BL Lac objects, taken from the RomaBZCat catalogue, for which spectroscopic information and SDSS photometry is available. We propose a new classification of BL Lacs in which the sources' type is not defined only on the basis of the peak frequency of the synchrotron component in their Spectral Energy Distribution (types L and H), but also on the relevance of this component with respect to the brightness of the host galaxy (types N and G, for nuclear or galaxy dominated sources). We found that the SDSS colour index u-r=1.4 is a good separator between these two types. We used multiband colour-colour plots to study the properties of the BL Lac classes and found that in the X-ray to radio flux ratio vs u-r plot most of the N (blue) sources are located in a rather narrow strip, while the G-sources (red) are spread in a large area, and most of them are located in galaxy clusters or interacting systems, suggesting that their X-ray emission is not from a genuine BL Lac nucleus but it is rel...

  12. Very high-resolution observations of the radio sources NRAO 150, OJ 287, 3C 273, M87, 1633+38, BL Lacertae, and 3C 454.3

    International Nuclear Information System (INIS)

    Very long baseline interferometer observations made at a wavelength of 2 and 2.8 cm with baselines ranging from 54 to 291 million wavelengths show a number of radio sources with only slightly resolved components, even on the longest baselines; the quasars 1633 + 38 and 3C 454.3, the objects OJ 287 and BL Lac, and the nucleus of M87 (Virgo A, 3C 274) all contain components < or approximately 0.4 milli-arcsec. The smallest component observed is in the core of 3C 454.3, which contains about 50% of the total flux density and is < or approximately 0.2 milli-arcsec in diameter. The compact component in the nucleus of M87 is < or approximately 1.5 light-months across, and contains about one-third of the total flux density of the nucleus at 2.8 cm. NRAO 150 and BL Lac are double: the components of NRAO 150 are separated by 0.6 milli-arcsec, while BL Lac has an elongated structure consisting of a large (1.4 milli-arcsec) component separated by 1.25 milli-arcsec from a smaller (0.5 milli-arcsec) variable one. The present data on 3C 273 are consistent with triple models similar to those discussed previously, but with a somewhat greater apparent separation of components

  13. Black hole mass and binary model for BL Lac object OJ 287

    OpenAIRE

    Liu, F. K.; Wu, Xue-Bing

    2002-01-01

    Recent intensive observations of the BL Lac object OJ 287 raise a lot of questions on the models of binary black holes, processing jets, rotating helical jets and thermal instability of slim accretion disks. After carefully analyzing their radio flux and polarization data, Valtaoja et al. (\\cite{valtaoja00}) propose a new binary model. Based on the black hole mass of $4 \\times 10^8 {\\rm M_\\odot}$ estimated with the tight correlations of the black hole masses and the bulge luminosity or centra...

  14. Modelling the IDV Emissions of the BL Lac Objects with a Langevin Type Stochastic Differential Equation

    Indian Academy of Sciences (India)

    C. S. Leung; J. Y. Wei; T. Harko; Z. Kovacs

    2011-03-01

    In this paper, we introduce a simplified model for explaining the observations of optical intra-day variability (IDV) of the BL Lac Objects. We assume that the source of the IDV are the stochastic oscillations of an accretion disk around a supermassive black hole. The stochastic fluctuations on the vertical direction of the accretion disk are described by using a Langevin type equation with a damping term and a random, white noise type force. Furthermore, preliminary numerical simulation results are presented, which are based on the numerical analysis of the Langevin stochastic differential equation.

  15. Exploring the bulk of the BL Lac object population: parsec scale radio properties and gamma ray emission

    Directory of Open Access Journals (Sweden)

    Giovannini G.

    2013-12-01

    Full Text Available BL Lac objects have been found to be the largest population of emitters in gamma-ray band. However, since they are relatively weak radio sources, their parsec scale structure and most of their radio properties are poorly known. To increase our knowledge of the BL Lac object population, we selected a sample of BL Lacs from the BZ Cat at low redshift (z < 0.2, with no constrain on the radio flux density and gamma-ray activity. We present here the results of a first VLBA observation at 8 and 15 GHz and shortly discuss their properties

  16. An Analysis of Periodic Components in BL Lac Object S5 0716 +714 with MUSIC Method

    Science.gov (United States)

    Tang, J.

    2012-01-01

    Multiple signal classification (MUSIC) algorithms are introduced to the estimation of the period of variation of BL Lac objects.The principle of MUSIC spectral analysis method and theoretical analysis of the resolution of frequency spectrum using analog signals are included. From a lot of literatures, we have collected a lot of effective observation data of BL Lac object S5 0716 + 714 in V, R, I bands from 1994 to 2008. The light variation periods of S5 0716 +714 are obtained by means of the MUSIC spectral analysis method and periodogram spectral analysis method. There exist two major periods: (3.33±0.08) years and (1.24±0.01) years for all bands. The estimation of the period of variation of the algorithm based on the MUSIC spectral analysis method is compared with that of the algorithm based on the periodogram spectral analysis method. It is a super-resolution algorithm with small data length, and could be used to detect the period of variation of weak signals.

  17. Optical and Radio variability of the Northern VHE gamma-ray emitting BL Lac objects

    CERN Document Server

    Lindfors, E J; Nilsson, K; Reinthal, R; Ramazani, V Fallah; Pavlidou, V; Max-Moerbeck, W; Richards, J; Berdyugin, A; Takalo, L; Sillanpää, A; Readhead, A C S

    2016-01-01

    We compare the variability properties of very high energy gamma-ray emitting BL Lac objects in the optical and radio bands. We use the variability information to distinguish multiple emission components in the jet, to be used as a guidance for spectral energy distribution modelling. Our sample includes 32 objects in the Northern sky that have data for at least 2 years in both bands. We use optical R-band data from the Tuorla blazar monitoring program and 15 GHz radio data from the Owens Valley Radio Observatory blazer monitoring program. We estimate the variability amplitudes using the intrinsic modulation index, and study the time-domain connection by cross-correlating the optical and radio light curves assuming power law power spectral density. Our sample objects are in general more variable in the optical than radio. We find correlated flares in about half of the objects, and correlated long-term trends in more than 40% of the objects. In these objects we estimate that at least 10%-50% of the optical emiss...

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

    Indian Academy of Sciences (India)

    Wang Hong-tao

    2014-03-01

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

  19. Contemporaneous broadband observations of three high-redshift BL Lac Objects

    OpenAIRE

    Ackermann, Markus; Ajello, M.; Bregeon, J.; Troja, E.; Vianello, G.; Wood, K. S.; Wood, M; Fermi-LAT Collaboration; Britto, R. J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.

    2016-01-01

    We have collected broadband spectral energy distributions (SEDs) of three BL Lac objects 3FGL J0022.1−1855 (z = 0.689), 3FGL J0630.9−2406 ($z\\quad \\gtrsim $ 1.239), and 3FGL J0811.2−7529 (z = 0.774), detected by Fermi with relatively flat gigaelectronvolt spectra. By observing simultaneously in the near-infrared to hard X-ray band, we can well characterize the high end of the synchrotron component of the SED. Thus, fitting the SEDs to synchro-Compton models of the dominant emission from the r...

  20. IUE observations of extragalactic objects

    Science.gov (United States)

    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.

  1. IUE observations of extragalactic objects

    International Nuclear Information System (INIS)

    During the commissioning phase of the International Ultraviolet Explorer several extragalactic objects were observed spectrally at low dispersion in the UV range lambdalambda1150-3200: the Seyfert galaxies NGC4151 and NGC1068, the QSO 3C273, the BL Lacertae object B2 1101 + 38, the giant eliptical 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. (author)

  2. Rapid Tev Gamma-ray Variability Of Bl Lac

    Science.gov (United States)

    Feng, Qi

    2011-09-01

    Recent VERITAS observations of BL Lacertae revealed rapid gamma-ray flaring of the object at TeV energies (Ong, 2011, ATel #3459). Here, we present preliminary results from the observations. The flaring activity was observed during a 20-minute exposure, when the flux above 200 GeV reached a peak of about 3x10^-6 m^-2s^-1 (roughly one and a half times the Crab Nebula flux). The light curve shows that the observations missed the rising phase of the flare but covered the decaying phase almost in its entirety. The decay time of the flare is about 4 minutes, making it one of the most rapid gamma-ray flares seen for any TeV blazars. Compared to several other blazars that are known to produce gamma-ray flares on a timescale of minutes, BL Lacertae produces the bulk of its radiation at much lower frequencies. The measured gamma-ray spectrum appears to be as soft as that of the non-flaring state, when compared with the published MAGIC spectrum of the source. We will discuss the implications of the results. VERITAS research is supported by grants from the U.S. Department of Energy, the U.S. National Science Foundation, the Smithsonian Institution, by NSERC in Canada, by STFC in the U.K. and by Science Foundation Ireland.

  3. Discovery of VHE gamma-rays from the BL Lac object PKS 0548-322

    CERN Document Server

    Akhperjanian, A G; de Almeida, U Barres; Bazer-Bachi, A R; Becherini, Y; Behera, B; Benbow, W; Bernlöhr, K; Bochow, A; Boisson, C; Bolmont, J; Borrel, V; Brucker, J; Brun, F; Brun, P; Bühler, R; Bulik, T; Büsching, I; Boutelier, T; Chadwick, P M; Charbonnier, A; Chaves, R C G; Cheesebrough, A; Chounet, L -M; Clapson, A C; Coignet, G; Dalton, M; Daniel, M K; Davids, I D; Degrange, B; Deil, C; Dickinson, H J; Djannati-Ataï, A; Domainko, W; Drury, L O'C; Dubois, F; Dubus, G; Dyks, J; Dyrda, M; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Feinstein, F; Fiasson, A; Förster, A; Fontaine, G; Füssling, M; Gabici, S; Gallant, Y A; Gérard, L; Gerbig, D; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Göring, D; Hauser, D; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Holleran, M; Hoppe, S; Horns, D; Jacholkowska, A; deJager, O C; Jahn, C; Jung, I; Katarzyński, K; Katz, U; Kaufmann, S; Kendziorra, E; Kerschhagg, M; Khangulyan, D; Khélifi, B; Keogh, D; Kluźniak, W; Kneiske, T; Komin, Nu; Kosack, K; Lamanna, G; Lenain, J -P; Lohse, T; Marandon, V; Martin, J M; Martineau-Huynh, O; Marcowith, A; Masbou, J; Maurin, D; McComb, T J L; Medina, M C; Moderski, R; Moulin, E; Naumann-Godo, M; deNaurois, M; Nedbal, D; Nekrassov, D; Nicholas, B; Niemiec, J; Nolan, S J; Ohm, S; Olive, J-F; Wilhelm, E de Oña; Orford, K J; Ostrowski, M; Panter, M; Arribas, M Paz; Pedaletti, G; Pelletier, G; Petrucci, P -O; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raubenheimer, B C; Raue, M; Rayner, S M; Renaud, M; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Ruppel, J; Sahakian, V; Santangelo, A; Schlickeiser, R; Schöck, F M; Schröder, R; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Sikora, M; Skilton, J L; Sol, H; Spangler, D; Stawarz, L; Steenkamp, R; Stegmann, C; Stinzing, F; Superina, G; Szostek, A; Tam, P H; Tavernet, J -P; Terrier, R; Tibolla, O; Tluczykont, M; vanEldik, C; Vasileiadis, G; Venter, C; Venter, L; Vialle, J P; Vincent, P; Vivier, M; Völk, H J; Volp, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A

    2010-01-01

    PKS 0548-322 (z=0.069) is a ``high-frequency-peaked'' BL Lac object and a candidate very high energy (VHE, E>100 GeV) gamma-ray emitter, due to its high X-ray and radio flux. Observations at the VHE band provide insights into the origin of very energetic particles present in this source and the radiation processes at work. We report observations made between October 2004 and January 2008 with the H.E.S.S. array, a four imaging atmospheric-Cherenkov telescopes. Contemporaneous UV and X-ray observations with the Swift satellite in November 2006 are also reported. PKS 0548-322 is detected for the first time in the VHE band with H.E.S.S. We measure an excess of 216 gamma-rays corresponding to a significance of 5.6 standard deviations. The photon spectrum of the source is described by a power-law, with a photon index of Gamma=2.86 +/- 0.34 (stat) +/- 0.10 (sys). The integral flux above 200 GeV is 1.3 % of the flux of the Crab Nebula, and is consistent with being constant in time. Contemporaneous Swift/XRT observat...

  4. X-RAY AND TeV EMISSIONS FROM HIGH-FREQUENCY-PEAKED BL LAC OBJECTS

    International Nuclear Information System (INIS)

    The majority of the extragalactic sources yet detected at TeV photon energies belong to the class of 'high-frequency-peaked BL Lac objects' (HBLs) that exhibit a spectral energy distribution with a lower peak in the X-ray band. Such spectra are well described in terms of a log-parabolic shape with considerable curvature, and widely interpreted as synchrotron emission from ultrarelativistic electrons outflowing in a relativistic jet; these are expected to radiate also in γ-rays through the inverse Compton process. Recently, we have compared the X-ray spectral parameter distributions of TeV detected HBLs (TBLs) with those undetected (UBLs), and found that the distributions of the peak energies Ep are similarly symmetric around a value of a few keVs for both subclasses, while the X-ray spectra are broader for TBLs than for UBLs. Here we propose an acceleration scenario to interpret both the Ep and the spectral curvature distributions in terms of a coherent and a stochastic acceleration mechanisms, respectively. We show how the curvature parameter b ≅ 0.3-0.7 of the synchrotron X-rays, which depends only on the latter acceleration component, can be related to the inverse Compton luminosity in γ-rays, thus introducing a link between the X-ray and the TeV observations of HBLs.

  5. VERITAS Observations of the BL Lac Object PG 1553+113

    CERN Document Server

    Aliu, E; Aune, T; Barnacka, A; Behera, B; Beilicke, M; Benbow, W; Berger, K; Bird, R; Buckley, J H; Bugaev, V; Byrum, K; Cardenzana, J V; Cerruti, M; Chen, X; Ciupik, L; Connolly, M P; Cui, W; Dickinson, H J; Dumm, J; Eisch, J D; Errando, M; Falcone, A; Federici, S; Feng, Q; Finley, J P; Fortin, P; Fortson, L; Furniss, A; Galante, N; Gillanders, G H; Griffin, S; Griffiths, S T; Grube, J; Gyuk, G; Håkansson, N; Hanna, D; Holder, J; Hughes, G; Humensky, T B; Johnson, C A; Kaaret, P; Kertzman, P Kar M; Khassen, Y; Kieda, D; Krawczynski, H; Krennrich, F; Kumar, S; Lang, M J; Madhavan, A; McArthur, S; McCann, A; Meagher, K; Millis, J; Moriarty, P; Nieto, D; de Bhróithe, A O'Faoláin; Ong, R A; Orr, M; Otte, A N; Park, N; Perkins, J S; Pohl, M; Popkow, A; Prokoph, H; Pueschel, E; Quinn, J; Ragan, K; Rajotte, J; Reyes, L C; Reynolds, P T; Richards, G T; Roache, E; Sembroski, G H; Shahinyan, K; Staszak, D; Telezhinsky, I; Tucci, J V; Tyler, J; Varlotta, A; Vassiliev, V V; Wakely, S P; Weinstein, A; Welsing, R; Wilhelm, A; Williams, D A; Zitzer, B

    2014-01-01

    We present results from VERITAS observations of the BL Lac object PG 1553+113 spanning the years 2010, 2011, and 2012. The time-averaged spectrum, measured between 160 and 560\\,GeV, is well described by a power law with a spectral index of $4.33 \\pm 0.09$. The time-averaged integral flux above $200\\,$GeV measured for this period was $(1.69 \\pm 0.06) \\times 10^{-11} \\, \\mathrm{ph} \\, \\mathrm{cm}^{-2} \\, \\mathrm{s}^{-1}$, corresponding to 6.9\\% of the Crab Nebula flux. We also present the combined $\\gamma$-ray spectrum from the Fermi Large Area Telescope and VERITAS covering an energy range from 100~MeV to 560~GeV. The data are well fit by a power law with an exponential cutoff at $\\rm {101.9 \\pm 3.2 \\, \\mathrm{GeV}} $. The origin of the cutoff could be intrinsic to PG~1553+113 or be due to the $\\gamma$-ray opacity of our universe through pair production off the extragalactic background light (EBL). Given lower limits to the redshift of $\\rm z \

  6. Dust in BL Lac objects and Fanaroff-Riley radio galaxies: infrared region

    Science.gov (United States)

    Seal Braun, P.

    2015-12-01

    Here 28 BL Lac objects, 18 FR I type radio galaxies, 4 FR I/II type radio galaxies and 10 FR II type radio galaxies are studied from FIR (far infrared) to optical region (180 μm to 0.44 μm) to understand the nature of infrared emission from these objects and the physical properties of dust in the emitting region. Using the flux densities from 2MASS, IRAS, ISO, SCUBA (40 % samples), WISE All-sky Data, AKARI (10 % samples) data and optical (B) observations, the spectral energy distributions are constructed. FIR and NIR spectral indices (α_{FIR} and α_{NIR}) are estimated. The dust temperatures and dust masses of all the samples are estimated from FIR flux densities. The SEDs of most of the samples (90 %) show steep slopes from FIR to optical region and about 10 % of the samples show flat continuous spectra from FIR to NIR region. The SEDs of 80 % FR I type radio galaxies and 1 out of 4 FR I/II type radio galaxies and two RBLs show a bump in the NIR to optical region. The SEDs of these sources are compared with Radiative transfer models. From FIR to MIR region, the SEDs of 90 % of the objects studied here can be fitted to the models with luminosities L˜ 10^{9.5} L0, considering uncertainty from 10 % to 20 %. But the observable fluxes in the NIR region are higher and can be fitted to other models with higher L˜ 10^{12.5} L0. Since there is a difference in emission in NIR region, mainly for FR I radio galaxies, so the variation of apparent K magnitudes with logarithm of redshift z is also studied. The WISE colours, (W1 - W2) and (W2 - W3) are compared with isodensity contours. Comparing with radiative transfer models it can be suggested that, in the FIR and MIR region the infrared emission is from the dust containing large grains, small graphites and PAHs at temperature ˜50 K-100 K. In the NIR region hot dust is mainly due to small grains at temperature ˜1200 K and the emission is mainly from synchrotron radiation produced in the inner part of the relativistic

  7. VERITAS OBSERVATIONS OF THE BL LAC OBJECT PG 1553+113

    Energy Technology Data Exchange (ETDEWEB)

    Aliu, E. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Archer, A.; Beilicke, M.; Buckley, J. H.; Bugaev, V. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Aune, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Barnacka, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Behera, B.; Chen, X. [DESY, Platanenallee 6, 15738 Zeuthen (Germany); Benbow, W.; Cerruti, M. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Berger, K. [Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States); Bird, R. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Byrum, K. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Cardenzana, J. V; Dickinson, H. J. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Cui, W. [Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 (United States); Dumm, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); and others

    2015-01-20

    We present results from VERITAS observations of the BL Lac object PG 1553+113 spanning the years 2010, 2011, and 2012. The time-averaged spectrum, measured between 160 and 560 GeV, is well described by a power law with a spectral index of 4.33 ± 0.09. The time-averaged integral flux above 200 GeV measured for this period was (1.69 ± 0.06) × 10{sup –11} photons cm{sup –2} s{sup –1}, corresponding to 6.9% of the Crab Nebula flux. We also present the combined γ-ray spectrum from the Fermi Large Area Telescope and VERITAS covering an energy range from 100 MeV to 560 GeV. The data are well fit by a power law with an exponential cutoff at 101.9 ± 3.2 GeV. The origin of the cutoff could be intrinsic to PG 1553+113 or be due to the γ-ray opacity of our universe through pair production off the extragalactic background light (EBL). Given lower limits to the redshift of z > 0.395 based on optical/UV observations of PG 1553+113, the cutoff would be dominated by EBL absorption. Conversely, the small statistical uncertainties of the VERITAS energy spectrum have allowed us to provide a robust upper limit on the redshift of PG 1553+113 of z ≤ 0.62. A strongly elevated mean flux of (2.50 ± 0.14) × 10{sup –11} photons cm{sup –2} s{sup –1} (10.3% of the Crab Nebula flux) was observed during 2012, with the daily flux reaching as high as (4.44±0.71)×10{sup −11} photons cm{sup −2} s{sup −1} (18.3% of the Crab Nebula flux) on MJD 56048. The light curve measured during the 2012 observing season is marginally inconsistent with a steady flux, giving a χ{sup 2} probability for a steady flux of 0.03%.

  8. Observations of the high-frequency-peaked BL Lac object 1ES 1218+304 with VERITAS

    CERN Document Server

    Fortin, Pascal

    2007-01-01

    The VERITAS collaboration has observed the high-frequency-peaked BL Lac object 1ES 1218+304 using an array of several imaging Cherenkov telescopes located at the Fred Lawrence Whipple Observatory in Southern Arizona. A gamma-ray signal was detected with high significance for the observations taken during several months in the 2006-2007 observing season. Here we present the detection of 1ES 1218+304 in very-high-energy gamma rays.

  9. New detection of high-energy gamma-ray sources associated with BL Lac objects above 10 GeV

    CERN Document Server

    Campana, R; Bernieri, E

    2015-01-01

    We report the detection of 19 new high-energy gamma-ray sources closely associated with BL Lac objects at energies higher than 10 GeV in the 6.3 years Fermi-Large Area Telescope sky, selected using the Minimum Spanning Tree (MST) clustering method. Photon clusters with good selection parameters were found matching the positions of known blazars in the fifth Roma-BZCAT catalogue. A brief summary of the properties of these sources is presented.

  10. The Luminosity Function of the Host Galaxies of QSOs and BL Lac Objects

    CERN Document Server

    Carangelo, N; Treves, A

    2001-01-01

    A clear insight of the galaxies hosting active galactic nuclei is of fundamental importance for understanding the processes of galaxies and nuclei formation and their cosmic evolution. A good characterization of the host galaxies properties requires images of excellent quality in order to disentangle the light of the galaxy from that of the bright nucleus. To this aim HST has provided a major improvement of data on QSOs (Disney et al. 1995; Bahcall et al. 1996, 1997; Boyce et al. 1998; McLure et al. 1999; Hamilton et al. 2000; Kukula et al. 2001) and BL Lacs (Scarpa et al. 2000, Urry et al. 2000). We present a comparative study of low redshift QSO and BL Lac host galaxy luminosity function (HGLF). To this aim we have considered samples of BL Lacs (Urry et al. 2000) and QSOs (Bahcall et al. 1997; Boyce et al. 1998; McLure et al. 1999) that have been well resolved by images obtained with WFPC2 on board of HST.

  11. Multi-wavelength study of flaring activity in BL Lac object S5 0716+714 during 2015 outburst

    OpenAIRE

    Chandra, Sunil; Zhang, Haocheng; Kushwaha, Pankaj; Singh, K.P.; Bottcher, M.; Kaur, Navpreet; Baliyan, K. S.

    2015-01-01

    We present a detailed investigation of the flaring activity observed from a BL Lac object, S5 0716+714 , during its brightest ever optical state in the second half of January 2015. Observed almost simultaneously in the optical, X-rays and {\\gamma}-rays, a significant change in the degree of optical polarization (PD) and a swing in the position angle (PA) of polarization were recorded. A detection in the TeV (VHE) was also reported by the MAGIC consortium during this flaring episode. Two promi...

  12. Computing Optical Variable Periods of BL Lac Object S5 0716+714 with Period04 Analysis Method

    Indian Academy of Sciences (India)

    Junping Fu; Xiong Zhang; Dingrong Xiong

    2014-09-01

    From a large volume of literature, we have collected effective observation of BL Lac object S5 0716+714 in the optical band, and constructed its long-term light curve from 1994 to 2006 AD. The light curve shows that S5 0716+714 is very active and exhibits very complicated non-sinusoidal variations. We used Period04 to analyse the period of light curve variation. Our results show that for S5 0716+714, the long-term period of variation is 3.3 yr which is consistent with the result of Raiter et al. (2003).

  13. An Analysis of Light Periods of BL Lac Object S5 0716+714 with the MUSIC Algorithm

    Science.gov (United States)

    Tang, Jie

    2012-07-01

    The multiple signal classification (MUSIC) algorithm is introduced to the estimation of light periods of BL Lac objects. The principle of the MUSIC algorithm is given, together with a testing on its spectral resolution by using a simulative signal. From a lot of literature, we have collected a large number of effective observational data of the BL Lac object S5 0716+714 in the three optical wavebands V, R, and I from 1994 to 2008. The light periods of S5 0716+714 are obtained by means of the MUSIC algorithm and average periodogram algorithm, respectively. It is found that there exist two major periodic components, one is the period of (3.33±0.08) yr, another is the period of (1.24±0.01) yr. The comparison of the performances of periodicity analysis of two algorithms indicates that the MUSIC algorithm has a smaller requirement on the sample length, as well as a good spectral resolution and anti-noise ability, to improve the accuracy of periodicity analysis in the case of short sample length.

  14. The jet of the BL Lac object PKS 0521 -365 in the near-IR : MAD adaptive optics observations

    CERN Document Server

    Falomo, R; Treves, A; Giovannini, G; Venturi, T; Moretti, A; Arcidiacono, C; Farinato, J; Ragazzoni, R; Diolaiti, E; Lombini, M; Tavecchio, F; Brast, R; Marchetti, E; Tordo, S

    2009-01-01

    BL Lac objects are low--power active nuclei exhibiting a variety of peculiar properties that are caused by the presence of a relativistic jet and orientation effects. We present here adaptive optics near-IR images at high spatial resolution of the nearby BL Lac object PKS 0521-365, which is known to display a prominent jet both at radio and optical frequencies. The observations were obtained in Ks--band using the ESO multi-conjugated adaptive optics demonstrator at the Very Large Telescope. This allowed us to obtain images with 0.1 arcsec effective resolution. We performed a detailed analysis of the jet and its related features from the near-IR images, and combined them with images previously obtained with HST in the R band and by a re-analysis of VLA radio maps. We find a remarkable similarity in the structure of the jet at radio, near-IR, and optical wavelengths. The broad--band emission of the jet knots is dominated by synchrotron radiation, while the nucleus also exhibits a significant inverse Compton com...

  15. Connection between inner jet kinematics and broadband flux variability in the BL Lac object S5 0716+714

    CERN Document Server

    Rani, B; Marscher, A P; Hodgson, J A; Fuhrmann, L; Angelakis, E; Britzen, S; Zensus, J A

    2015-01-01

    We present a high-frequency very long baseline interferometry (VLBI) kinematical study of the BL Lac object S5 0716+714 over the time period of September 2008 to October 2010. The aim of the study is to investigate the relation of the jet kinematics to the observed broadband flux variability. We find significant non-radial motions in the jet outflow of the source. In the radial direction, the highest measured apparent speed is \\sim37 c, which is exceptionally high, especially for a BL Lac object. Patterns in the jet flow reveal a roughly stationary feature \\sim0.15 mas downstream of the core. The long-term fits to the component trajectories reveal acceleration in the sub-mas region of the jet. The measured brightness temperature, T_{B}, follows a continuous trend of decline with distance, T_B \\propto r_{jet}^{-(2.36\\pm0.41)}, which suggests a gradient in Doppler factor along the jet axis. Our analysis suggest that a moving disturbance (or a shock wave) from the base of the jet produces the high-energy (optica...

  16. Phylogenetic Position of Barbus lacerta Heckel, 1843

    Directory of Open Access Journals (Sweden)

    Mustafa Korkmaz

    2015-11-01

    As a result, five clades come out from phylogenetic reconstruction and in phylogenetic tree Barbus lacerta determined to be sister group of Barbus macedonicus, Barbus oligolepis and Barbus plebejus complex.

  17. Discovery of VHE gamma-rays from the high-frequency-peaked BL Lac object RGB J0152+017

    CERN Document Server

    Aharonian, F; Barresde Almeida, U; Bazer-Bachi, A R; Behera, B; Beilicke, M; Benbow, W; Bernlöhr, K; Boisson, C; Borrel, V; Braun, I; Brion, E; Brucker, J; Buhler, R; Bulik, T; Büsching, I; Boutelier, T; Carrigan, S; Chadwick, P M; Chaves, R C G; Chounet, L M; Clapson, A C; Coignet, G; Cornils, R; Costamante, L; Dalton, M; Degrange, B; Dickinson, H J; Djannati-Ata, A; Domainko, i W; O'Connor-Drury, L; Dubois, F; Dubus, G; Dyks, J; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Feinstein, F; Fiasson, A; Förster, A; Fontaine, G; Fuling, M; Gabici, S; Gallant, Y A; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Hadjichristidis, C; Hauser, D; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Holleran, M; Hoppe, S; Horns, D; Jacholkowska, A; De Jager, O C; Jung, I; Katarzynski, K; Kaufmann, S; Kendziorra, E; Kerschhaggl, M; Khelifi, B; Keogh, D; Komin, Nu; Kosack, K; Lamanna, G; Latham, I J; Lenain, J P; Lohse, D Khangulyan T; Martin, J M; Martineau-Huynh, O; Marcowith, A; Masterson, C; Maurin, D; McComb, T J L; Moderski, R; Moulin, E; Naumann-Godo, M; De Naurois, Mathieu; Nedbal, D; Nekrassov, D; Nolan, S J; Ohm, S; Olive, J P; de Ona Wilhelmi, E; Orford, K J; Osborne, J L; Ostrowski, M; Panter, M; Pedaletti, G; Pelletier, G; Petrucci, P O; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, Andreas G; Raubenheimer, B C; Raue, M; Rayner, S M; Renaud, M; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Ruppel, J; Sahakian, V V; Santangelo, A; Schlickeiser, R; Schock, F M; Schroder, R; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Sol, H; Spangler, D; Stawarz, L; Steenkamp, R; Stegmann, C; Superina, G; Tam, P H; Tavernet, J P; Terrier, R; Van Eldik, C; Vasileiadis, G; Venter, C; Vialle, J P; Vincent, P; Vivier, M; Völk, H J; Volpe, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A

    2008-01-01

    Aims: The BL Lac object RGB J0152+017 (z=0.080) was predicted to be a very high-energy (VHE; > 100 GeV) gamma-ray source, due to its high X-ray and radio fluxes. Our aim is to understand the radiative processes by investigating the observed emission and its production mechanism using the High Energy Stereoscopic System (H.E.S.S.) experiment. Methods: We report recent observations of the BL Lac source RGB J0152+017 made in late October and November 2007 with the H.E.S.S. array consisting of four imaging atmospheric Cherenkov telescopes. Contemporaneous observations were made in X-rays by the Swift and RXTE satellites, in the optical band with the ATOM telescope, and in the radio band with the Nancay Radio Telescope. Results: A signal of 173 gamma-ray photons corresponding to a statistical significance of 6.6 sigma was found in the data. The energy spectrum of the source can be described by a powerlaw with a spectral index of 2.95+/-0.36stat+/-0.20syst. The integral flux above 300 GeV corresponds to ~2% of the ...

  18. Phylogenetic Position of Barbus lacerta Heckel, 1843

    OpenAIRE

    Mustafa Korkmaz

    2015-01-01

    The genus Barbus is characterized by a complex taxonomical structure, due to high number of species and its morphological plasticity; it counts more than 25 species in Europe, displaying different ecological preferences. 21 taxon’s from Barbus genus including Barbus lacerta was used in phylogenetic analysis. Cytochrome oxidase I (COI) gene sequence analysis of Barbus lacerta is presented firstly in this study. A phylogenetic tree (neighbor-joining and maximum likelihood analysis) was reco...

  19. EVN Observations of HESS J1943+213: Evidence for an Extreme TeV BL Lac Object

    Science.gov (United States)

    Akiyama, Kazunori; Stawarz, Łukasz; Tanaka, Yasuyuki T.; Nagai, Hiroshi; Giroletti, Marcello; Honma, Mareki

    2016-06-01

    We report on the 1.6 GHz (18 cm) very long baseline interferometry (VLBI) observations of the unresolved, steady TeV source HESS J1943+213 located in the Galactic plane, performed with the European VLBI Network (EVN) in 2014. Our new observations with a nearly full EVN array provide the deepest image of HESS J1943+213 at the highest resolution ever achieved, enabling us to resolve the long-standing issues of the source identification. The milliarcsecond-scale structure of HESS J1943+213 has a clear asymmetric morphology consisting of a compact core and a diffuse jet-like tail. This is broadly consistent with the previous e-EVN observations of the source performed in 2011 and re-analyzed in this work. The core component is characterized by the brightness temperature of ≳ 1.8× {10}9 K, which is typical for low-luminosity blazars in general. Overall, the radio properties of HESS J1943+213 are consistent with the source classification as an “extreme high-frequency-peaked BL Lac object.” Remarkably, we note that because HESS J1943+213 does not reveal any optical or infrared signatures of the active galactic nucleus activity, it would never be recognized and identified as a BL Lac object if not for its location close to the Galactic plane where the High Energy Stereoscopic System surveyed for and the follow-up dedicated X-ray and radio studies triggered by the source detection in the TeV range. Our results suggest, therefore, a presence of an unrecognized, possibly very numerous population of particularly extreme HBLs and simultaneously demonstrate that the low-frequency VLBI observations with high angular resolution are indispensable for a proper identification of such objects.

  20. Chaotic Behaviour of Intra-Day Variability of BL Lac Object S5 0716+714

    Indian Academy of Sciences (India)

    Shuhong Li; Jianwen Ou; Zheng Liu

    2014-06-01

    An optical monitoring shows Blazar object S5 0716+714 has complex Intra-Day Variability (IDV) behaviour. In this paper, we introduce a method of non-linear time series analysis, and calculate the correlation dimension of the IDV light curves of S5 0716+714 over seven nights in the December of 2006. According to our calculations, the correlation dimension ≈ 1.993-5.178 for all of the observed data, it is implied that the IDV behaviour may be a chaotic system with some additional noise.

  1. Active Galactic Nuclei, Quasars, BL Lac Objects and X-Ray Background

    Science.gov (United States)

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2005-01-01

    The XMM COSMOS survey is producing the large surface density of X-ray sources anticipated. The first batch of approx. 200 sources is being studied in relation to the large scale structure derived from deep optical/near-IR imaging from Subaru and CFHT. The photometric redshifts from the opt/IR imaging program allow a first look at structure vs. redshift, identifying high z clusters. A consortium of SAO, U. Arizona and the Carnegie Institute of Washington (Pasadena) has started a large program using the 6.5meter Magellan telescopes in Chile with the prime objective of identifying the XMM X-ray sources in the COSMOS field. The first series of observing runs using the new IMACS multi-slit spectrograph on Magellan will take place in January and February of 2005. Some 300 spectra per field will be taken, including 70%-80% of the XMM sources in each field. The four first fields cover the center of the COSMOS field. A VLT consortium is set to obtain bulk redshifts of the field galaxies. The added accuracy of the spectroscopic redshifts over the photo-z's will allow much lower density structures to be seen, voids and filaments. The association of X-ray selected AGNs, and quasars with these filaments, is a major motivation for our studies. Comparison to the deep VLA radio data now becoming available is about to begin.

  2. Long term lightcurve of the BL Lac object 1ES 0229+200 at TeV energies

    CERN Document Server

    Cologna, Gabriele; Wagner, Stefan J; Wierzcholska, Alicja; Romoli, Carlo; Kurtanidze, Omar

    2015-01-01

    The high-frequency peaked BL Lac object 1ES 0229+200 (z = 0.14) was first detected in very high energy (VHE, E > 100 GeV) $\\gamma$-rays by the H.E.S.S. (High Energy Stereoscopic System) collaboration in 2006. No flux variability was reported in the initial study and its spectral characteristics have been used to derive constraints on the extragalactic background light (EBL) and on the intergalactic magnetic field (IGMF). 1ES 0229+200 has been observed with H.E.S.S. for $\\sim$130 hours from 2004 to 2013: the full dataset analysed with a more sensitive method will be presented here. The results indicate that the source is not constant and displays flux variability on yearly and monthly timescales. The existence of flux variability affects the derivation of the constraints on the IGMF. The H.E.S.S. observations cover several simultaneous multi-frequency campaigns and the VHE variations are compared with those reported in different bands.

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

    CERN Document Server

    :,; Acero, F; Aharonian, F; Akhperjanian, A G; Angüner, E; Anton, G; Balenderan, S; Balzer, A; Barnacka, A; Becherini, Y; Tjus, J Becker; 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; Drury, L O'C; 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; Wilhelmi, E de O\; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Parsons, R D; Arribas, M Paz; 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; Reyes, R de los; 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

    2013-01-01

    The detection of the high-frequency peaked BL Lac object (HBL) SHBL J001355.9-185406 ($z$=0.095) at high (HE; 100 MeV$100\\,{\\rm GeV}$) with the \\fer\\ Large Area Telescope (LAT) and the High Energy Stereoscopic System (H.E.S.S.) is reported. Dedicated observations have been performed with the H.E.S.S. telescopes, leading to a detection at the $5.5\\,\\sigma$ significance level. The measured flux above 310 GeV is $(8.3 \\pm 1.7_{\\rm{stat}}\\pm 1.7_{\\rm{sys}})\\times 10^{-13}$ photons \\cms\\ (about 0.6% of that of the Crab Nebula), and the power law spectrum has a photon index of \\indexHESS. Using 3.5 years of publicly available \\fla\\ data, a faint counterpart has been detected in the LAT data at the $5.5\\,\\sigma$ significance level, with an integrated flux above 300 MeV of $(9.3 \\pm 3.4_{\\rm stat} \\pm 0.8_{\\rm sys})\\times 10^{-10}$ photons \\cms\\ and a photon index of $\\Gamma = 1.96 \\pm 0.20_{\\rm stat} \\pm 0.08_{\\rm sys}$. X-ray observations with \\textit{Swift}-XRT allow the synchrotron peak energy in $\

  4. Discovery of hard-spectrum \\gamma-ray emission from the BL Lac object 1ES 0414+009

    CERN Document Server

    Abramowski, A; Aharonian, F; Akhperjanian, A G; Anton, G; Balzer, A; Barnacka, A; de Almeida, U Barres; Becherini, Y; Becker, J; Behera, B; 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; Chounet, L -M; Clapson, A C; Coignet, G; 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; Dubois, F; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Egberts, K; Eger, P; Espigat, P; Fallon, L; Farnier, C; 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; Goret, P; Göring, D; Häffner, S; Hague, J D; Hampf, D; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Hofverberg, P; Holler, M; Horns, D; Jacholkowska, A; de Jager, O C; Jahn, C; Jamrozy, M; Jung, I; Kastendieck, M A; Katarzynski, K; Katz, U; Kaufmann, S; Keogh, D; Khangulyan, D; Khélifi, B; Kluźniak, D Klochkov W; Kneiske, T; Komin, Nu; Kosack, K; Kossakowski, R; Laffon, H; Lamanna, G; Lennarz, D; Lohse, T; Lopatin, A; Lu, C -C; Marandon, V; Marcowith, A; Masbou, J; Maurin, D; Maxted, N; Mayer, M; McComb, T J L; Medina, M C; Méhault, J; Moderski, R; Moulin, E; Naumann, C L; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Nguyen, N; Nicholas, B; Niemiec, J; Nolan, S J; Ohm, S; Wilhelmi, E de Ona; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Arribas, M Paz; Pedaletti, G; Pelletier, G; Petrucci, P -O; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raue, M; Rayner, S M; Reimer, A; Reimer, O; Renaud, M; Reyes, R de los; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Ruppel, J; Sahakian, V; Sanchez, D A; Santangelo, A; Schlickeiser, R; Schöck, F M; Schulz, A; Schwanke, U; Schwarzburg, S; Schwemmer, S; Sheidaei, F; Sikora, M; Skilton, J L; Sol, H; Spengler, G; Stawarz, L; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Szostek, A; Tavernet, J -P; Terrier, R; Tluczykont, M; Valerius, K; van Eldik, C; Vasileiadis, G; Venter, C; Vialle, J P; 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; Costamante, L; Fegan, S; Ajello, M

    2012-01-01

    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) gamma-rays due to its high X-ray and radio flux. Observations in the VHE gamma-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 gamma-ray spectrum might provide further limits on the level of the Extragalactic Background Light (EBL). We report observations made between October 2005 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 ...

  5. On the redshift of the very high-energy gamma-ray BL Lac object S2 0109+22

    Science.gov (United States)

    Paiano, S.; Landoni, M.; Falomo, R.; Scarpa, R.; Treves, A.

    2016-05-01

    The determination of the redshift of extragalactic gamma-ray sources is of fundamental importance for the interpretation of their emission models and extragalactic population studies, active galactic nuclei classification schemes, and to study the interaction with the extragalactic background light. Here we focus on the BL Lac S2 0109+22, recently detected at very high energies. We obtained a high signal-to-noise optical spectrum at Gran Telescopio Canarias for the source over the spectral range 4000-10 000 Å, to search for spectral features of the host galaxy and/or of the nuclear source and it was compared with previous observations in order to confirm and/or dispute its redshift determination. We find the S2 0109+22 optical spectrum is well represented by a power-law continuum without any absorption or emission feature of equivalent width >0.1 Å. Based on the new optical spectrum, we are able to set a redshift lower limit z > 0.35, assuming the source is hosted by a massive elliptical galaxy typical for this class of sources. The redshift z = 0.265 proposed in the literature for this object is most probably referred to a r = 18.3 galaxy at 15 arcsec from S2 0109. This galaxy could belong to a group of faint galaxies located at z ˜ 0.26.

  6. Multi-wavelength study of flaring activity in BL Lac object S5 0716+714 during 2015 outburst

    CERN Document Server

    Chandra, Sunil; Kushwaha, Pankaj; Singh, K P; Bottcher, M; Kaur, Navpreet; Baliyan, K S

    2015-01-01

    We present a detailed investigation of the flaring activity observed from a BL Lac object, S5 0716+714 , during its brightest ever optical state in the second half of January 2015. Observed almost simultaneously in the optical, X-rays and {\\gamma}-rays, a significant change in the degree of optical polarization (PD) and a swing in the position angle (PA) of polarization were recorded. A detection in the TeV (VHE) was also reported by the MAGIC consortium during this flaring episode. Two prominent sub-flares, peaking about 5-days apart, were seen in almost all the energy bands. The multi-wavelength light-curves, spectral energy distribution (SED) and polarization are modeled using the time-dependent code developed by Zhang et al. (2014). This model assumes a straight jet threaded by large scale helical magnetic fields taking into account the light travel time effects, incorporating synchrotron flux and polarization in 3D geometry. The rapid variation in PD and rotation in PA are most likely due to re-connectio...

  7. EVN Observations of HESS J1943+213: Evidence for an Extreme TeV BL Lac Object

    CERN Document Server

    Akiyama, Kazunori; Tanaka, Yasuyuki T; Nagai, Hiroshi; Giroletti, Marcello; Honma, Mareki

    2016-01-01

    We report on the 1.6 GHz (18 cm) VLBI observations of the unresolved, steady TeV source HESS J1943+213 located in the Galactic plane, performed with the European VLBI Network (EVN) in 2014. Our new observations with a nearly full EVN array provide the deepest image of HESS J1943+213 at the highest resolution ever achieved, enabling us to resolve the long-standing issues of the source identification. The milliarcsecond-scale structure of HESS J1943+213 has a clear asymmetric morphology, consisting of a compact core and a diffuse jet-like tail. This is broadly consistent with the previous e-EVN observations of the source performed in 2011, and re-analyzed in this work. The core component is characterized by the brightness temperature of $\\gtrsim1.8 \\times 10^9$ K, which is typical for low-luminosity blazars in general. Overall, radio properties of HESS J1943+213 are consistent with the source classification as an "extreme high-frequency-peaked BL Lac object". Remarkably, we note that since HESS J1943+213 does n...

  8. The underluminous Type Ia Supernova 2005bl and the class of objects similar to SN 1991bg

    OpenAIRE

    Taubenberger, S.; Hachinger, S.; Pignata, G.; Mazzali, P. A.; Contreras, C.; Valenti, S.; Pastorello, A.; Elias-Rosa, N.; Bärnbantner, O.; Barwig, H.; Benetti, S.; Dolci, M.; Fliri, J.; Folatelli, G.; Freedman, W. L.

    2007-01-01

    Optical observations of the Type Ia supernova (SN Ia) 2005bl in NGC 4070, obtained from -6 to +66 d with respect to the B-band maximum, are presented. The photometric evolution is characterised by rapidly-declining light curves and red colours at peak and soon thereafter. With M_B,max = -17.24 the SN is an underluminous SN Ia, similar to the peculiar SNe 1991bg and 1999by. This similarity also holds for the spectroscopic appearance, the only remarkable difference being the likely presence of ...

  9. Observation of the BL Lac objects 1ES 1215+303 and 1ES 1218+304 with the MAGIC telescopes

    OpenAIRE

    Colin, Pierre; Gonzalez, Josefa Becerra; Lindfors, Elina; Lombardi, Saverio; Sitarek, Julian; Stamera, Antonio; collaboration, for the MAGIC

    2011-01-01

    The two BL Lac objects 1ES 1215+303 and 1ES 1218+304, separated by 0.8 deg, were observed with the MAGIC telescopes in 2010 and 2011. The 20 hours of data registered in January 2011 resulted in the first detection at Very High Energy (>100 GeV) of 1ES 1215+303 (also known as ON-325). This observation was triggered by a high optical state of the source reported by the Tuorla blazar monitoring program. Comparison with the 25 hours of data carried out from January to May 2010 suggests that 1ES 1...

  10. Fermi-LAT detection of hard spectrum and enhanced gamma-ray emission from the BL Lac object PKS 1717+177

    Science.gov (United States)

    Ciprini, Stefano

    2015-12-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed a gamma-ray flare from a source positionally consistent with the BL Lac object PKS 1717+177 (also known as S3 1717+17, OT 129, and 3FGL J1719.2+1744, Acero et al. 2015, ApJS, 218, 23), with radio coordinates (J2000.0), R.A.: 259.804368 deg, Dec.: 17.751788 deg (Johnston et al. 1995, AJ, 110, 880).

  11. MAGIC detection of short-term variability of the high-peaked BL Lac object 1ES 0806+524

    CERN Document Server

    Aleksić, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barrio, J A; González, J Becerra; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Wilhelmi, E de O na; Mendez, C Delgado; Di Pierro, F; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fernández-Barral, A; Fidalgo, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; López, R J García; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Godinović, N; noz, A González Mu; Gozzini, S R; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Knoetig, M L; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Neustroev, V; Niedzwiecki, A; Rosillo, M Nievas; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Moroni, P G Prada; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Garcia, J Rodriguez; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Stamerra, A; Steinbring, T; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzić, T; Tescaro, D; Teshima, M; Thaele, J; Torres, D F; Toyama, T; Treves, A; Vogler, P; Will, M; Zanin, R; Berger, K; Buson, S; D'Ammando, F; Gasparrini, D; Hovatta, T; Max-Moerbeck, W; Readhead, A; Richards, J

    2015-01-01

    The high-frequency-peaked BL Lac (HBL) 1ES 0806+524 (z = 0.138) was discovered in VHE $\\gamma$ rays in 2008. Until now, the broad-band spectrum of 1ES 0806+524 has been only poorly characterized, in particular at high energies. We analysed multiwavelength observations from $\\gamma$ rays to radio performed from 2011 January to March, which were triggered by the high activity detected at optical frequencies. These observations constitute the most precise determination of the broad-band emission of 1ES 0806+524 to date. The stereoscopic MAGIC observations yielded a $\\gamma$-ray signal above 250 GeV of $(3.7 \\pm 0.7)$ per cent of the Crab Nebula flux with a statistical significance of 9.9 $\\sigma$. The multiwavelength observations showed significant variability in essentially all energy bands, including a VHE $\\gamma$-ray flare that lasted less than one night, which provided unprecedented evidence for short-term variability in 1ES 0806+524. The spectrum of this flare is well described by a power law with a photon...

  12. Time Series Photometry of KZ Lacertae

    Science.gov (United States)

    Joner, Michael D.

    2016-01-01

    We present BVRI time series photometry of the high amplitude delta Scuti star KZ Lacertae secured using the 0.9-meter telescope located at the Brigham Young University West Mountain Observatory. In addition to the multicolor light curves that are presented, the V data from the last six years of observations are used to plot an O-C diagram in order to determine the ephemeris and evaluate evidence for period change. We wish to thank the Brigham Young University College of Physical and Mathematical Sciences as well as the Department of Physics and Astronomy for their continued support of the research activities at the West Mountain Observatory.

  13. Discovery of VHE gamma-ray emission from the BL Lac object B3 2247+381 with the MAGIC telescopes

    CERN Document Server

    Aleksić, J; Antonelli, L A; Antoranz, P; Asensio, M; Backes, M; Barrio, J A; Bastieri, D; González, J Becerra; Bednarek, W; Berdyugin, A; Berger, K; Bernardini, E; Biland, A; Blanch, O; Bock, R K; Boller, A; Bonnoli, G; Tridon, D Borla; Braun, I; Bretz, T; Cañellas, A; Carmona, E; Carosi, A; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Cossio, L; Covino, S; Dazzi, F; De Angelis, A; De Caneva, G; del Pozo, E De Cea; De Lotto, B; Mendez, C Delgado; Ortega, A Diago; Doert, M; Domínguez, A; Prester, D Dominis; Dorner, D; Doro, M; Elsaesser, D; Ferenc, D; Fonseca, M V; Font, L; Fruck, C; López, R J García; Garczarczyk, M; Garrido, D; Giavitto, G; Godinović, N; Hadasch, D; Häfner, D; Herrero, A; Hildebrand, D; Höhne-Mönch, D; Hose, J; Hrupec, D; Huber, B; Jogler, T; Kellermann, H; Klepser, S; Krähenbühl, T; Krause, J; La Barbera, A; Lelas, D; Leonardo, E; Lindfors, E; Lombardi, S; López, M; López-Oramas, A; Lorenz, E; Makariev, M; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Mariotti, M; Martínez, M; Mazin, D; Meucci, M; Miranda, J M; Mirzoyan, R; Miyamoto, H; Moldón, J; Moralejo, A; Munar-Adrover, P; Nieto, D; Nilsson, K; Orito, R; Oya, I; Paneque, D; Paoletti, R; Pardo, S; Paredes, J M; Partini, S; Pasanen, M; Pauss, F; Perez-Torres, M A; Persic, M; Peruzzo, L; Pilia, M; Pochon, J; Prada, F; Moroni, P G Prada; Prandini, E; Puljak, I; Reichardt, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Rügamer, S; Saggion, A; Saito, K; Saito, T Y; Salvati, M; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shayduk, M; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Spiro, S; Stamatescu, V; Stamerra, A; Steinke, B; Storz, J; Strah, N; Surić, T; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzić, T; Tescaro, D; Teshima, M; Tibolla, O; Torres, D F; Treves, A; Uellenbeck, M; Vankov, H; Vogler, P; Wagner, R M; Weitzel, Q; Zabalza, V; Zandanel, F; Zanin, R; Kadenius, V; Weidinger, M; Buson, S

    2012-01-01

    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 hours of good quality very high energy (VHE) $\\gamma$-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 $\\gamma$-ray (HE, 0.1 GeV-100 GeV) data from the Fermi satellite. The BL Lac object B3 2247+381 (z=0.119) was detected, for the first time, at VHE $\\gamma$-rays at a statistical significance of 5.6 $\\sigma$. A soft VHE spectrum with a photon index of -3.2 $\\pm$ 0.6 was determined. No significant short term flux variations were found. We model the spectral energy distribution using a one-zone SSC-model, which can successfully describe our data.

  14. MAGIC detection of short-term variability of the high-peaked BL Lac object 1ES 0806+524

    Science.gov (United States)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; de Oña Wilhelmi, E.; Delgado Mendez, C.; Di Pierro, F.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Nishijima, K.; Noda, K.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Stamerra, A.; Steinbring, T.; Strzys, M.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Torres, D. F.; Toyama, T.; Treves, A.; Vogler, P.; Will, M.; Zanin, R.; Berger, K.; Buson, S.; D'Ammando, F.; Gasparrini, D.; Hovatta, T.; Max-Moerbeck, W.; Readhead, A.; Richards, J.

    2015-07-01

    The high-frequency-peaked BL Lac (HBL) 1ES 0806+524 (z = 0.138) was discovered in very high energy (VHE) γ-rays in 2008. Until now, the broad-band spectrum of 1ES 0806+524 has been only poorly characterized, in particular at high energies. We analysed multiwavelength observations from γ-rays to radio performed from 2011 January to March, which were triggered by the high activity detected at optical frequencies. These observations constitute the most precise determination of the broad-band emission of 1ES 0806+524 to date. The stereoscopic Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) observations yielded a γ-ray signal above 250 GeV of (3.7 ± 0.7) per cent of the Crab Nebula flux with a statistical significance of 9.9σ. The multiwavelength observations showed significant variability in essentially all energy bands, including a VHE γ-ray flare that lasted less than one night, which provided unprecedented evidence for short-term variability in 1ES 0806+524. The spectrum of this flare is well described by a power law with a photon index of 2.97 ± 0.29 between ˜150 GeV and 1 TeV and an integral flux of (9.3 ± 1.9) per cent of the Crab nebula flux above 250 GeV. The spectrum during the non-flaring VHE activity is compatible with the only available VHE observation performed in 2008 with VERITAS when the source was in a low optical state. The broad-band spectral energy distribution can be described with a one-zone synchrotron self-Compton model with parameters typical for HBLs, indicating that 1ES 0806+524 is not substantially different from the HBLs previously detected.

  15. Swift XRT and UVOT deep observations of the high energy peaked BL Lac object PKS 0548-322 close to its brightest state

    CERN Document Server

    Perri, M; Giommi, P; Massaro, E; Nesci, R; Tramacere, A; Capalbi, M; Cusumano, G; Chincarini, G; Tagliaferri, G; Burrows, D N; Vanden Berk, D E; Gehrels, N; Sambruna, R M

    2006-01-01

    We present the results of a spectral analysis of 5 Swift XRT and UVOT observations of the BL Lac object PKS 0548-322 carried out over the period April-June 2005. The X-ray flux of this high energy peaked BL Lac (HBL) source was found to be approximately constant at a level of F(2-10 keV) ~ 4x10^-11 erg cm^-2 s^-1, a factor of 2 brighter than when observed by BeppoSAX in 1999 and close to the maximum intensity reported in the Einstein Slew Survey. The very good statistics obtained in the 0.3-10 keV Swift X-ray spectrum allowed us to detect highly significant deviations from a simple power law spectral distribution. A log-parabolic model describes well the X-ray data and gives a best fit curvature parameter of 0.18 and peak energy in the Spectral Energy Distribution of about 2 keV. The UV spectral data from Swift UVOT join well with a power law extrapolation of the soft X-ray data points suggesting that the same component is responsible for the observed emission in the two bands. The combination of synchrotron ...

  16. VERITAS detection of $\\gamma$-ray flaring activity from the BL Lac object 1ES 1727+502 during bright moonlight observations

    CERN Document Server

    Archambault, S; Beilicke, M; Benbow, W; Bird, R; Biteau, J; Bouvier, A; Bugaev, V; Cardenzana, J V; Cerruti, M; Chen, X; Ciupik, L; Connolly, M P; Cui, W; Dickinson, H J; Dumm, J; Eisch, J D; Errando, M; Falcone, A; Feng, Q; Finley, J P; Fleischhack, H; Fortin, P; Fortson, L; Furniss, A; Gillanders, G H; Griffin, S; Griffiths, S T; Grube, J; Gyuk, G; Håkansson, N; Hanna, D; Holder, J; Humensky, T B; Johnson, C A; Kaaret, P; Kar, P; Kertzman, M; Khassen, Y; Kieda, D; Krause, M; Krennrich, F; Kumar, S; Lang, M J; Maier, G; McArthur, S; McCann, A; Meagher, K; Millis, J; Moriarty, P; Mukherjee, R; Nieto, D; de Bhróithe, A O'Faoláin; Ong, R A; Otte, A N; Park, N; Pohl, M; Popkow, A; Prokoph, H; Pueschel, E; Quinn, J; Ragan, K; Reyes, L C; Reynolds, P T; Richards, G T; Roache, E; Santander, M; Sembroski, G H; Shahinyan, K; Smith, A W; Staszak, D; Telezhinsky, I; Tucci, J V; Tyler, J; Varlotta, A; Vincent, S; Wakely, S P; Weinstein, A; Welsing, R; Wilhelm, A; Williams, D A; Zitzer, B; Hughes, Z D

    2015-01-01

    During moonlit nights, observations with ground-based Cherenkov telescopes at very high energies (VHE, $E>100$ GeV) are constrained since the photomultiplier tubes (PMTs) in the telescope camera are extremely sensitive to the background moonlight. Observations with the VERITAS telescopes in the standard configuration are performed only with a moon illumination less than 35$\\%$ of full moon. Since 2012, the VERITAS collaboration has implemented a new observing mode under bright moonlight, by either reducing the voltage applied to the PMTs (reduced-high-voltage configuration, RHV), or by utilizing UV-transparent filters. While these operating modes result in lower sensitivity and increased energy thresholds, the extension of the available observing time is useful for monitoring variable sources such as blazars and sources requiring spectral measurements at the highest energies. In this paper we report the detection of $\\gamma$-ray flaring activity from the BL Lac object 1ES 1727+502 during RHV observations. Thi...

  17. Multi-Epoch VLBA Observations of EGRET-Detected Quasars and BL Lac Objects Superluminal Motion of Gamma-Ray Bright Blazars

    CERN Document Server

    Jorstad, S G; Mattox, J R; Wehrle, A E; Bloom, S D; Yurchenko, A V; Jorstad, Svetlana G; Marscher, Alan P; Mattox, John R; Wehrle, Ann E; Bloom, Steven D; Yurchenko, Alexei V

    2001-01-01

    We present the results of a program to monitor the structure of the radio emission in 42 $\\gamma$-ray bright blazars (31 quasars and 11 BL Lac objects) with the VLBA at 43, 22, and occasionally 15 and 8.4 GHz, over the period from November 1993 to July 1997. We determine proper motions in 33 sources and find that the apparent superluminal motions in $\\gamma$-ray sources are much faster than for the general population of bright compact radio sources. This follows the strong dependence of the $\\gamma$-ray flux on the level of relativistic beaming for both external-radiation Compton and synchrotron self-Compton emission. There is a positive correlation (correlation coefficient $r$=0.45) between the flux density of the VLBI core and the $\\gamma$-ray flux and a moderate correlation (partial correlation coefficient $r$=0.31) between $\\gamma$-ray apparent luminosity and superluminal velocities of jet components, as expected if the $\\gamma$-ray emission originates in a very compact region of the relativistic jet and ...

  18. Discovery of very high energy gamma-ray emission from the BL Lac object PKS 0301-243 with H.E.S.S

    CERN Document Server

    Abramowski, A; Aharonian, F; Ait, F; Akhperjanian, A G; Angüner, E; Anton, G; Balenderan, S; Balzer, A; Barnacka, A; Becherini, Y; Becker, J; Bernlöhr, K; Birsin, E; Bissaldi, E; Biteau, J; Böttcher, M; 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; Drury, L O'C; 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; Giebels, B; Glicenstein, J F; Grondin, M -H; Grudzìnska, 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; Marx, R; 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; Wilhelmi, E de Oña; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Parsons, R D; Arribas, M Paz; 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; Reyes, R de los; 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; Spies, F; Stawarz, L; 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; Weitzel, Q; White, R; Wierzcholska, A; Willmann, P; Wörnlein, A; Wouters, D; Zacharias, M; Zajczyk, A; Zdziarski, A A; Zech, A; Zechlin, H -S

    2013-01-01

    The active galactic nucleus PKS 0301-243 (z=0.266) is a high-synchrotron-peaked BL Lac object that is detected at high energies (HE, 100 MeV 100 GeV) by the High Energy Stereoscopic System (H.E.S.S.) from observations between September 2009 and December 2011 for a total live time of 34.9 hours. Gamma rays above 200 GeV are detected at a significance of 9.4{\\sigma}. A hint of variability at the 2.5{\\sigma} level is found. An integral flux I(E > 200 GeV) = (3.3 +/- 1.1_stat +/- 0.7_syst)e-12 ph cm^-2s^-1 and a photon index {\\Gamma} = 4.6 +/- 0.7_stat +/- 0.2_syst are measured. Multi-wavelength light curves in HE, X-ray and optical bands show strong variability, and a minimal variability timescale of eight days is estimated from the optical light curve. A single-zone leptonic synchrotron self-Compton scenario satisfactorily reproduces the multi-wavelength data. In this model, the emitting region is out of equipartition and the jet is particle dominated. Because of its high redshift compared to other sources obse...

  19. Discovery of VHE \\gamma-ray emission and multi-wavelength observations of the BL Lac object 1RXS J101015.9-311909

    CERN Document Server

    Abramowski, A; 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; Wilhelmi, E de Oña; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Arribas, M Paz; Pekeur, N W; Pelletier, G; Perez, J; Petrucci, P -O; Peyaud, B; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raue, M; Rayner, S M; Reimer, A; Reimer, O; Renaud, M; Reyes, R de los; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Sahakian, V; Sanchez, D A; Santangelo, A; Schlickeiser, R; Schulz, A; Schwanke, U; Schwarzburg, S; Schwemmer, S; Sheidaei, F; Skilton, J L; Sol, H; Spengler, G; Stawarz, 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

    2012-01-01

    1RXS J101015.9-311909 is a galaxy located at a redshift of z=0.14 hosting an active nucleus 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 2006-10 with H.E.S.S. 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\\sigma. The photon spectrum above 0.2 TeV can be described by a power-law with a photon index of \\Gamma\\ = 3.08\\pm0.42_{stat}\\pm0.20_{sys}. The integral flux above 0.2 TeV is about 0.8% of the flux of the Crab nebula and shows no significant variabi...

  20. The WEBT campaign on the BL Lac object PG 1553+113 in 2013. An analysis of the enigmatic synchrotron emission

    CERN Document Server

    Raiteri, C M; Villata, M; Larionov, V M; Acosta-Pulido, J A

    2015-01-01

    A multifrequency campaign on the BL Lac object PG 1553+113 was organized by the Whole Earth Blazar Telescope (WEBT) in 2013 April-August, involving 19 optical, two near-IR, and three radio telescopes. The aim was to study the source behaviour at low energies during and around the high-energy observations by the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes in April-July. We also analyse the UV and X-ray data acquired by the Swift and XMM-Newton satellites in the same period. The WEBT and satellite observations allow us to detail the synchrotron emission bump in the source spectral energy distribution (SED). In the optical we found a general bluer-when-brighter trend. The X-ray spectrum remained stable during 2013, but a comparison with previous observations suggests that it becomes harder when the X-ray flux increases. The long XMM-Newton exposure reveals a curved X-ray spectrum. In the SED, the XMM-Newton data show a hard near-UV spectrum, while Swift data display a softer shape that is co...

  1. Perplexing correlations between Gamma-ray emission and parsec-scale jet orientation variations in the BL Lac object S5 0716+714

    CERN Document Server

    Rani, B; Marscher, A P; Jorstad, S G; Hodgson, J A; Fuhrmann, L; Zensus, J A

    2015-01-01

    The analysis of $\\gamma$-ray flux variability along with the parsec-scale jet kinematics suggests that the high-energy radiation in the BL Lac object S5 0716+714 has a significant correlation with the mm-VLBI core flux density and with the local orientation of the inner jet flow. For the first time in any blazar, we report a significant correlation between the $\\gamma$-ray flux variations and the variations in the local orientation of the jet outflow (position angle). We find that the $\\gamma$-ray flux variations lead the 7~mm VLBI core flux variations by 82$\\pm$32~days, which suggests that the high-energy emission in S5 0716+714 is coming from a region located 3.8$\\pm$1.9~parsecs closer to the central black hole than the "core" seen on the mm-VLBI images. The results imply a strong physical and casual connection between $\\gamma$-ray emission and the inner jet morphology in the source.

  2. Application of the MST clustering to the high energy γ-ray sky. I—New possible detection of high-energy γ-ray emission associated with BL Lac objects

    Science.gov (United States)

    Campana, R.; Massaro, E.; Bernieri, E.; D'Amato, Q.

    2015-12-01

    In this paper we show an application of the Minimum Spanning Tree (MST) clustering method to the high-energy γ-ray sky observed at energies higher than 10 GeV in 6.3 years by the Fermi-Large Area Telescope. We report the detection of 19 new high-energy γ-ray clusters with good selection parameters whose centroid coordinates were found matching the positions of known BL Lac objects in the 5th Edition of the Roma-BZCAT catalogue. A brief summary of the properties of these sources is presented.

  3. Detection of Possible Quasi-periodic Oscillations in the Long-term Optical Light Curve of the BL Lac Object OJ 287

    CERN Document Server

    Bhatta, G; Stawarz, Ł; Ostrowski, M; Winiarski, M; Ogłoza, W; Dróżdz, M; Siwak, M; Liakos, A; Kozieł-Wierzbowska, D; Gazeas, K; Debski, B; Kundera, T; Stachowski, G; Paliya, V S

    2016-01-01

    Detection of periodicity in the broad-band non-thermal emission of blazars has so far been proven to be elusive. However, there are a number of scenarios which could lead to quasi-periodic variations in blazar light curves. For example, orbital or thermal/viscous period of accreting matter around central supermassive black holes could, in principle, be imprinted in the multi-wavelength emission of small-scale blazar jets, carrying as such crucial information about plasma conditions within the jet launching regions. In this paper, we present the results of our time series analysis of $\\sim 9.2$ year-long, and exceptionally well-sampled optical light curve of the BL Lac OJ 287. The study primarily uses the data from our own observations performed at the Mt. Suhora and Krak\\'ow Observatories in Poland, and at the Athens Observatory in Greece. Additionally, SMARTS observations were used to fill in some of the gaps in the data. The Lomb-Scargle Periodogram and the Weighted Wavelet Z-transform methods were employed...

  4. Observations of low and intermediate-frequency-peaked BL Lacs above 100 GeV with VERITAS

    Directory of Open Access Journals (Sweden)

    Errando M.

    2013-12-01

    Full Text Available Most of the ~ 50 blazars detected to date at TeV energies (E > 0.1 TeV are high-frequency-peaked BL Lacs (HBLs. Only a handful episodic detections of low- and intermediate-frequency-peaked BL Lacs (LBL/IBLs, with synchrotron peak frequencies in the infrared and optical regime have been reported by ground-based gamma-ray telescopes, typically during high-flux states. The VERITAS array located in southern Arizona has observed five known TeV LBL/IBLs since 2009: 3C 66A, WComae, PKS 1424+240, S5 0716+714 and BL Lacertae, with exposures of 5-10 hours/year, which so far resulted in the detection of a bright, sub-hour timescale gamma-ray flare of BL Lacertae in June 2011. We also report the detection and characterization of two new IBLs: VER J0521+211 and B2 1215+30.

  5. Examination of the hippocampal contribution to serotonin 5-HT2A receptor-mediated facilitation of object memory in C57BL/6J mice.

    Science.gov (United States)

    Zhang, Gongliang; Cinalli, David; Cohen, Sarah J; Knapp, Kristina D; Rios, Lisa M; Martínez-Hernández, José; Luján, Rafael; Stackman, Robert W

    2016-10-01

    The rodent hippocampus supports non-spatial object memory. Serotonin 5-HT2A receptors (5-HT2AR) are widely expressed throughout the hippocampus. We previously demonstrated that the activation of 5-HT2ARs enhanced the strength of object memory assessed 24 h after a limited (i.e., weak memory) training procedure. Here, we examined the subcellular distribution of 5-HT2ARs in the hippocampal CA1 region and underlying mechanisms of 5-HT2AR-mediated object memory consolidation. Analyses with immuno-electron microscopy revealed the presence of 5-HT2ARs on the dendritic spines and shafts of hippocampal CA1 neurons, and presynaptic terminals in the CA1 region. In an object recognition memory procedure that places higher demand on the hippocampus, only post-training systemic or intrahippocampal administration of the 5-HT2AR agonist TCB-2 enhanced object memory. Object memory enhancement by TCB-2 was blocked by the 5-HT2AR antagonist, MDL 11,937. The memory-enhancing dose of systemic TCB-2 increased extracellular glutamate levels in hippocampal dialysate samples, and increased the mean in vivo firing rate of hippocampal CA1 neurons. In summary, these data indicate a pre- and post-synaptic distribution of 5-HT2ARs, and activation of 5-HT2ARs selectively enhanced the consolidation of object memory, without affecting encoding or retrieval. The 5-HT2AR-mediated facilitation of hippocampal memory may be associated with an increase in hippocampal neuronal firing and glutamate efflux during a post-training time window in which recently encoded memories undergo consolidation. PMID:27114257

  6. Estradiol-Induced Enhancement of Object Memory Consolidation Involves NMDA Receptors and Protein Kinase A in the Dorsal Hippocampus of Female C57BL/6 Mice

    OpenAIRE

    Michael C. Lewis; Kerr, Kristin M.; Orr, Patrick T.; Frick, Karyn M.

    2008-01-01

    This study examined the role of dorsal hippocampal NMDA receptors and PKA activation in 17β-estradiol (E2)-induced enhancement of object memory consolidation. Mice explored two identical objects during training, after which they immediately received intraperitoneal injections of 0.2 mg/kg E2, and bilateral dorsal hippocampal infusions of Vehicle, the NMDA receptor antagonist APV (2.5 μg/side), or the cAMP inhibitor Rp-cAMPS (18.0 μg/side). Retention was tested 48 hours later. The enhanced obj...

  7. Association of Mc1r variants with ecologically relevant phenotypes in the European ocellated lizard, Lacerta lepida

    DEFF Research Database (Denmark)

    Nunes, V. L.; Miraldo, A.; Beaumont, M. A.;

    2011-01-01

    range of vertebrate taxa, was assessed in European ocellated lizards (Lacerta lepida) to search for associations with melanin-based colour phenotypes. Lacerta lepida subspecies' distribution is associated with the three major bio-climatic regions in the Iberian Peninsula. A nonconserved and derived...

  8. The Multi-periodic Blazhko Modulation of CZ Lacertae

    CERN Document Server

    Sódor, Á; Szeidl, B; Váradi, M; Henden, A; Vida, K; Hurta, Zs; Posztobányi, K; Dékány, I; Szing, A

    2010-01-01

    Thorough analysis of the multicolour CCD observations of the RRab-type variable, CZ Lacertae is presented. The observations were carried out in two consecutive observing seasons in 2004 and 2005 within the framework of the Konkoly Blazhko Survey of bright, northern, short-period RRab variables. The O-C variation of CZ Lac indicated that a significant period decrease took place just around the time of the CCD observations. Our data gave a unique opportunity to study the related changes in the pulsation and modulation properties of a Blazhko star in detail. Two different period components ($\\approx$14.6 d and $\\approx$18.6 d) of the Blazhko modulation were identified. Both modulation components had similar strength. The periods and amplitudes of the modulations changed significantly from the first season to the next, meanwhile, the mean pulsation amplitude slightly decreased. The modulation frequencies were in a 5:4 resonance ratio in the first observing season then the frequencies shifted in opposite direction...

  9. 3BL hotel management

    OpenAIRE

    MALECHOVÁ, Vendula

    2013-01-01

    The work is dedicated to Corporate Social Responsibility (CSR) and its application in the hotel. Part of this work are interviews with representatives of hotels representing the CSR best practices and interviews with other selected subjects. Comparison of the information reflects the current status of implementation of CSR in hotel management in the Czech Republic. The output of work is created CSR matrix. According the principles of 3 BL management matrix visualizes the organization current ...

  10. UV-Deprived Coloration Reduces Success in Mate Acquisition in Male Sand Lizards (Lacerta agilis)

    OpenAIRE

    Mats Olsson; Staffan Andersson; Erik Wapstra

    2011-01-01

    BACKGROUND: Recent work on animal signals has revealed a wide occurrence of UV signals in tetrapods, in particular birds, but also in lizards (and perhaps other Squamate reptiles). Our previous work on the Swedish sand lizard (Lacerta agilis) has verified, both in correlative selection analyses in the wild and with laboratory and field experiments, the importance of the green 'badge' on the body sides of adult males for securing mating opportunities, probably mostly through deterring rival ma...

  11. Additional photoelectric observations and analysis of the variability of the beta Cephei stars 12 and 16 Lacertae

    Science.gov (United States)

    Jarzebowski, T.; Jerzykiewicz, M.; Rios Herrera, M.; Rios Berumen, M.

    1980-04-01

    We present photoelectric observations of two Cephei variables - 12 and 16 Lacertae- made in 1977 in the Observatory of Zacatecas. The results of a frequency analysis made with these data and with the data obtained in the same year at the San Pedro Martir, Chiran and Bialkow Observatories are also given.

  12. Spotted fever group rickettsiae detected in immature stages of ticks parasitizing on Iberian endemic lizard Lacerta schreiberi Bedriaga, 1878

    Czech Academy of Sciences Publication Activity Database

    Kubelová, M.; Papoušek, I.; Bělohlávek, T.; Goüy de Bellocq, Joëlle; Baird, Stuart J. E.; Široký, P.

    2015-01-01

    Roč. 6, č. 6 (2015), s. 711-714. ISSN 1877-959X Institutional support: RVO:68081766 Keywords : Spotted fever group rickettsiae * Rickettsia monacensis * Rickettsia helvetica * Ixodes ricinus * Lacerta schreiberi Subject RIV: EG - Zoology Impact factor: 2.718, year: 2014

  13. DISCOVERY OF X-RAY EMISSION IN THE OLD CLASSICAL NOVA DK LACERTAE

    International Nuclear Information System (INIS)

    We report the discovery of X-ray emission at the position of the old classical nova DK Lacertae using the Swift satellite. Three observations were conducted using the X-Ray Telescope 62 years after the discovery of the nova, yielding 46 source signals in an exposure time of 4.8 ks. A background-subtracted count rate was 9 ± 2 × 10–3 counts s–1, corresponding to a detection significance level of 5σ. The X-ray spectrum was characterized by a continuum extending up to about 7 keV, which can be modeled by a power-law component with a photon index of 1.4-5.6, or by a thermal bremsstrahlung component with a temperature of 0.7-13.3 keV, convolved with interstellar absorption with an equivalent hydrogen column density of 0.3-2.4 × 1022 cm–2. Assuming a distance of 3900 pc to the source, the luminosity was 1032-1034 erg s–1 in the 0.3-10 keV energy band. The origin of X-rays is considered to be either mass accretion on the white dwarf or adiabatic shocks in nova ejecta, with the former appearing much more likely. In either case, DK Lacertae represents a rare addition to the exclusive club of X-ray emitting old novae.

  14. Blått vann

    OpenAIRE

    Jensen, Poul Johannes

    2013-01-01

    Verket består av to "blå vann" i høybrent porselæn som er plassert i en sansehage. Et rundt "vann" med diameter 350 cm og retangulært "vann" på 125 x 700 cm. Begge "vann" er belyst med ledlys som kan skifte fargetemperatur/farge. Her er brukt blå porselensfliser for å gi en følelse av vann. Flisene som er ca. 23 x 23 cm er etter 1. brenning dekorert med vannløselige keramiske farger som tildels glir i hverandre og veksler i farge og nyanse, fra blått til grønt ettersom hvilke farge som ...

  15. Phylogeography and demographic history of Lacerta lepida in the Iberian Peninsula

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...

  16. Den Blå Drage

    DEFF Research Database (Denmark)

    Ingerslev, Gitte Holten

    Denne publikation i serien Læselyst tjener tre formål. Den evaluerer læseprojektet Den blå drage i efteråret 2004 på Byskolen i Svendborg ? et projekt ledet af forfatteren Josefine Ottesen. Desuden gøres der rede for nogle af de teorier der støtter og begrunder arbejdsmåde og resultater i projektet...

  17. IDV Observations of BL0716+714 at 5 GHz

    Indian Academy of Sciences (India)

    H.-G Song; X. Liu; J. Liu; N. Marchili; T. P. Krichbaum

    2011-03-01

    A selected sample of intra-day variable AGN had been observed for 3–4 days per month at the Urumqi Observatory. The sample includes 7 target sources and 7 calibrators. The BL Lac object B0716+714 shows prominent intraday and long term variations.

  18. Properties of optically selected BL Lac candidates from the SDSS

    CERN Document Server

    Kügler, S D; Heidt, J; Esser, J; Schultz, T

    2014-01-01

    \\textbf{Context.} Deep optical surveys open the avenue for find 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. \\textbf{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. \\textbf{Methods.} We examine their variability characteristics, determine their broad-band radio-UV SEDs, and search for the presence of a host galaxy. In addition we present new optical spectra for 27 targets with improved S/N with respect to the SDSS spectra. \\textbf{Results.} At least 59% of our targets h...

  19. Infrared Polarization and Beaming Effect for BL Lac Objects

    Institute of Scientific and Technical Information of China (English)

    MEI Dong-Cheng; XIE Guang-Zhong

    2001-01-01

    With the idea of the beaming models, we derive a relation between the observed polarization and Dopplercorrected magnitude; that is, the observed polarization is in anti-correlation with the Doppler-corrected magnitude. Making use of the infrared data observed simultaneously by Impey et al. [Mon. Not. R. Astron. Soc.200 (1982) 19; 209 (1984) 245] and Holmes et al. [ibid. 210 (1984) 961] we found that: (1) there is a significant correlation between the observed maximum polarization and Doppler-corrected magnitude but the polarization is not in anti-correlation with the Doppler-corrected magnitude; (2) the maximum infrared polarization is strongly correlated with the maximum optical polarization. Our conclusion is that the infrared polarization depends only on the degree of ordering of the magnetic field in the synchrotron emission regions and not on the beaming effect.Both infrared and optical emissions originate from the synchrotron radiation.

  20. UV-deprived coloration reduces success in mate acquisition in male sand lizards (Lacerta agilis.

    Directory of Open Access Journals (Sweden)

    Mats Olsson

    Full Text Available BACKGROUND: Recent work on animal signals has revealed a wide occurrence of UV signals in tetrapods, in particular birds, but also in lizards (and perhaps other Squamate reptiles. Our previous work on the Swedish sand lizard (Lacerta agilis has verified, both in correlative selection analyses in the wild and with laboratory and field experiments, the importance of the green 'badge' on the body sides of adult males for securing mating opportunities, probably mostly through deterring rival males rather than attracting females. The role of UV in communication has, however, never been examined. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that when measured immediately after spring skin shedding, there is also signaling in the UV. By UV-depriving the signal (reflectance with sun block chemicals fixated with permeable, harmless spray dressing, we show that males in the control group (spray dressing only had significantly higher success in mate acquisition than UV-deprived males. CONCLUSIONS/SIGNIFICANCE: These results suggest that at least two colour traits in sand lizards, badge area and UV, contribute to rival deterrence and/or female choice on UV characters, which elevates success in mate acquisition in UV intact male sand lizards.

  1. LOBI-BL-40: an approach to the SGTR phenomenology in a one loop PWR

    International Nuclear Information System (INIS)

    The aim of the ''LOBI-BL-40'' project is to study the phenomena and the recovery techniques involved in Steam Generator Tube Rupture (SGTR) events in a commercial single-loop PWR plant. Experimental support for the project will be provided by the BL-40 experiment, to be carried out at the LOBI installation (JRC, Ispra-Varese, Italy). This paper describes the project, its objectives, the activities involved and the progress made, with special attention to specification of the BL-40 experiments. The work is being undertaken by the Spanish utility UNION-FENOSA. (author)

  2. Dynamical analyses of the companions orbiting eclipsing binaries - I. SW Lacertae

    Science.gov (United States)

    Yuan, Jinzhao; Şenavci, Hakan Volkan

    2014-03-01

    New mid-eclipse times of the short-period eclipsing binary SW Lacertae are reported, and two cyclical variations are found in the corresponding O - C diagram. The proposed light-travel time model is refined. The best fit suggests that two possible circumbinary companions are in a near 3:1 mean-motion resonance with periods of 27.01 and 82.61 yr. Based on the best-fitting solution, we have studied the stabilities of the two companions moving on a series of mutually inclined orbits. The results show that no orbital configurations can survive for >1000 yr. Then, non-Keplerian corrections to the initial conditions and the more distant K-dwarf companion discovered by Ruciński, Pribulla & van Kerkwijk, moving on assumed circular orbits with wide ranges of orbital inclinations, are considered in our numerical simulations. The outcome similarly reveals that the whole system is yet short-term unstable. Perhaps, one or both cyclical variations in the mid-eclipse times are attributed to irregular mass exchange and/or magnetic cycles in the magnetically active W UMa system. Despite this, the instability of the system may also arise from the large uncertainties in orbital parameters. So, secular observations of this target are needed to determine the eccentricity of the outmost companion and the orbital period of the middle companion with much higher precision. Our results suggest that, if the two inner companions do exist, they should be on mutually inclined orbits of >100°, with the minimum masses of 0.62 and 1.94 M⊙ for the innermost and middle components, respectively. Our work demonstrates that it is important and necessary to perform dynamical analyses before a discovery of two or more circumbinary companions is announced.

  3. GENERALIZED FUZZY FILTERS OF BL-ALGEBRAS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The concept of quasi-coincidence of a fuzzy interval value with an interval valued fuzzy set is considered. In fact, this is a generalization of quasi-coincidence of a fuzzy point with a fuzzy set. By using this new idea, the notion of interval valued (∈, ∈∨q)-fuzzy filters in BL-algebras which is a generalization of fuzzy filters of BL-algebras, is defined, and related properties are investigated. In particular, the concept of a fuzzy subgroup with thresholds is extended to the concept of an interval valued fuzzy filter with thresholds in BL-algebras.

  4. A Large Sample of BL Lacs from SDSS and FIRST

    CERN Document Server

    Plotkin, Richard M; Hall, Patrick B; Margon, Bruce; Voges, Wolfgang; Schneider, Donald P; Stinson, Gregory; York, Donald G

    2008-01-01

    We present a large sample of 501 radio-selected BL Lac candidates from the combination of the Sloan Digital Sky Survey (SDSS) Data Release 5 optical spectroscopy and from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) radio survey; this is one of the largest BL Lac samples yet assembled, and each object emerges with homogeneous data coverage. Each candidate is detected in the radio from FIRST and confirmed in SDSS optical spectroscopy to have: (1) no emission feature with measured rest equivalent width larger than 5 Angstroms; and (2) no measured Ca II H/K depression larger than 40%. We subdivide our sample into 426 higher confidence candidates and 75 lower confidence candidates. We argue that contamination from other classes of objects that formally pass our selection criteria is small, and we identify a few very rare radio AGN with unusual spectra that are probably related to broad absorption line quasars. About one-fifth of our sample were known BL Lacs prior to the SDSS. A preliminary ana...

  5. On the magnetization of BL Lac jets

    CERN Document Server

    Tavecchio, F

    2015-01-01

    The current paradigm foresees that relativistic jets are launched as magnetically dominated flows, whose magnetic power is progressively converted to kinetic power of of the matter of the jet, until equipartition is reached. Therefore, at the end of the acceleration phase, the jet should still carry a substantial fraction ($\\approx$ half) of its power in the form of a Poynting flux. It has been also argued that, in these conditions, the best candidate particle acceleration mechanism is efficient reconnection of magnetic field lines, for which it is predicted that magnetic field and accelerated relativistic electron energy densities are in equipartition.Through the modeling of the jet non--thermal emission, we explore if equipartition is indeed possible in BL Lac objects, i.e. low-power blazars with weak or absent broad emission lines. We find that one-zone models (for which only one region is involved in the production of the radiation we observe) the particle energy density is largely dominating (by 1-2 orde...

  6. Galactic membership of BL Her type variable stars

    CERN Document Server

    Jurkovic, Monika I; Ninković, Slobodan

    2016-01-01

    As the RR Lyrae stars evolve on the Hertzsprung-Russell diagram they are believed to become short period Type II Cepheids, known as BL Her type (with a pulsation period from $1$ to $3-8$ days). Assuming that their mass is around $0.5 - 0.6 {\\rm M}_{\\odot}$, and that they are low metallicity objects, they were thought to belong to the halo of the Milky Way. We investigated seven Galactic short period Type II Cepheids (BL Her, SW Tau, V553 Cen, DQ And, BD Cas, V383 Cyg, and KT Com) in order to establish their membership within the Galactic structure using the kinematic approach. $Gaia$ should provide us with more data needed to conduct the study of the whole sample.

  7. Varieties Generated by Standard BL-algebras

    Czech Academy of Sciences Publication Activity Database

    Haniková, Zuzana

    2014-01-01

    Roč. 31, č. 1 (2014), s. 15-33. ISSN 0167-8094 R&D Projects: GA ČR GAP202/10/1826 Institutional research plan: CEZ:AV0Z10300504 Institutional support: RVO:67985807 Keywords : substructural logic * fuzzy logic * BL * standard BL- algebra * variety of algebra s Subject RIV: BA - General Mathematics Impact factor: 0.621, year: 2014

  8. A View through Faraday's fog Parsec scale rotation measures in AGN

    CERN Document Server

    Zavala, R T

    2003-01-01

    Rotation measure observations of 9 quasars, 4 BL Lacertae objects, and 3 radio galaxies are presented. The rest frame rotation measures in the cores of the quasars and the jets of the radio galaxy M87 are several thousand radians per meter squared. The BL Lacertae objects and the jets of the quasars have rest frame rotation measures of a few hundred radians per meter squared. A nuclear rotation measure of 500 radians per meter squared in the rest frame is suggested as the dividing line between quasar and BL Lacertae objects. The substantial rotation measures of the BL Lacertae objects and quasars cast doubt on the previous polarization position angle investigations of these objects at frequencies of 15 GHz or less. BL Lacertae itself has a rotation measure that varies in time, similar to the behavior observed for the quasars 3C273 and 3C279. A simple model with magnetic fields of 40 microgauss or less can account for the observed rotation measures.

  9. Asteroseismology of the Beta Cephei star 12 (DD) Lacertae: photometric observations, pulsational frequency analysis and mode identification

    CERN Document Server

    Handler, G; Rodríguez, E; Uytterhoeven, K; Amado, P J; Dorokhova, T N; Dorokhov, N I; Poretti, E; Sareyan, J P; Parrao, L; Lorenz, D; Zsuffa, D; Drummond, R; Daszynska-Daszkiewicz, J; Verhoelst, T; De Ridder, J; Acke, B; Bourge, P O; Movchan, A I; Garrido, R; Paparo, M; Sahin, T; Antoci, V; Udovichenko, S N; Csorba, K; Crowe, R; Berkey, B; Stewart, S; Terry, D; Mkrtichian, D E; Aerts, C

    2006-01-01

    We report a multisite photometric campaign for the Beta Cephei star 12 Lacertae. 750 hours of high-quality differential photoelectric Stromgren, Johnson and Geneva time-series photometry were obtained with 9 telescopes during 190 nights. Our frequency analysis results in the detection of 23 sinusoidal signals in the light curves. Eleven of those correspond to independent pulsation modes, and the remainder are combination frequencies. We find some slow aperiodic variability such as that seemingly present in several Beta Cephei stars. We perform mode identification from our colour photometry, derive the spherical degree l for the five strongest modes unambiguously and provide constraints on l for the weaker modes. We find a mixture of modes of 0 <= l <= 4. In particular, we prove that the previously suspected rotationally split triplet within the modes of 12 Lac consists of modes of different l; their equal frequency splitting must thus be accidental. One of the periodic signals we detected in the light c...

  10. The hard synchrotron X-ray spectrum of the TeV BL Lac 1ES 1426+428

    CERN Document Server

    Wolter, A; Ghisellini, G; Tavecchio, F; Maraschi, L; Costamante, L; Celotti, A; Ghirlanda, G

    2007-01-01

    We have observed 1ES 1426+428 with INTEGRAL detecting it up to $\\sim$150 keV. The spectrum is hard, confirming that this source is an extreme BL Lac object, with a synchrotron component peaking, in a $\

  11. About the article by S. S. Liberman and N. V. Pokrovskaya on the thermal biology of Lacerta agilis (1943

    Directory of Open Access Journals (Sweden)

    Cherlin Vladimir

    2014-11-01

    Full Text Available More than seventy years ago in 1943 Zoological Journal (Moscow published the article “Materials on the ecology of Lacerta agilis”, by S. S. Liberman and N. V. Pokrovskaya that was prepared under the supervision of A.M.Sergeev. This article can be rightly considered as the first basic work in the field of reptile’s thermal biology, as it was published one year earlier than the well-known paper by R. B. Cowles and Ch. M. Bogert (Cowles, Bogert, 1944, which now is considered to be the beginning of this direction of scientific research. But the scientific importance of this paper is not less than that of Cowles and Bogert. In the first part of this paper, the authors described temperature live conditions in Lacerta agilis and their thermal endurance, in the second part – the peculiarities of their breeding and development of eggs. Both parts are equally interesting and qualitative as well as methodically correct. The authors used the complex of terms and concepts, that later became basic in reptile’s thermal biology. They studied the complete daily course of body temperatures in these lizards, for the first time they paid attention to the fact, that during the period of full activity of lizards their body temperature is almost stable. In this article some very important innovations were proposed, in particular, measuring body temperature instead of that of the soil. Unfortunately, some of these innovations (the description of activity statuses, using the mode for definition of preferred temperatures, etc.. were not applied by other researchers. In this paper the brief biographic information about S. S. Liberman and A. M. Sergeev is given. The data about N. V. Pokrovskaya has not found

  12. Chaos in hydrodynamic BL Herculis models

    CERN Document Server

    Smolec, R

    2014-01-01

    We present non-linear, convective, BL Her-type hydrodynamic models that show complex variability characteristic for deterministic chaos. The bifurcation diagram reveals a rich structure, with many phenomena detected for the first time in hydrodynamic models of pulsating stars. The phenomena include not only period doubling cascades en route to chaos (detected in earlier studies) but also periodic windows within chaotic band, type-I and type-III intermittent behaviour, interior crisis bifurcation and others. Such phenomena are known in many textbook chaotic systems, from the simplest discrete logistic map, to more complex systems like Lorenz equations. We discuss the physical relevance of our models. Although except of period doubling such phenomena were not detected in any BL Her star, chaotic variability was claimed in several higher luminosity siblings of BL Her stars - RV Tau variables, and also in longer-period, luminous irregular pulsators. Our models may help to understand these poorly studied stars. Pa...

  13. Cloning and expression of human papilloma virus type 6b-L1 gene

    Directory of Open Access Journals (Sweden)

    Lie-hua DENG

    2011-03-01

    Full Text Available Objective To investigate the expression of green fluorescent protein plasmid of human papilloma virus 6b L1 gene(HPV6bL1 in eukaryotic cells.Methods The L1 gene of PQE40-HPV6bL1 was amplified by PCR,purified by restriction enzyme digestion,and then connected to eukaryotic expression plasmid PEGFP-C1.The recombinant expression vector was then transformed into E.coli DH5a,which was identified by BamH Ⅰ and Hand Ⅲ digestion and the positive vector was selected.The recombinant plasmid PEGFP-HPV6bL1 was transfected into COS-7 cells by liposomal transfection technique and the expression of fusion protein was observed under fluorescence microscope.The generation of HPV6bL1 mRNA was detected by RT-PCR.Results Identification of PEGFP-HPV6bL1 by enzyme digestion and sequencing showed that the length,direction and inserted location of target,which was inserted into the recombinant,was correct and the expression of EGFP in transfected cell was observed.Conclusions A new type of green fluorescent HPV6bL1 eukaryotic expression system has been established.It may provide a research foundation for the study of the protein.

  14. Extreme BL Lacs: probes for cosmology and UHECR candidates

    CERN Document Server

    Tavecchio, F

    2015-01-01

    High-energy observations of extreme BL Lac objects, such as 1ES0229+200 or 1ES 0347-121, recently focused interest both for blazar and jet physics and for the implication on the extragalactic background light and intergalactic magnetic field estimate. Moreover, their enigmatic properties have been interpreted in a scenario in which their primary high- energy output is through a beam of high-energy hadrons. However, despite their possible important role in all these topics, the number of these extreme highly peaked BL Lac objects (EHBL) is still rather small. Aiming at increase their number, we selected a group of EHBL candidates considering those undetected (or only barely detected) by the LAT onboard Fermi and characterized by a high X-ray versus radio flux ratio. We assembled the multi-wavelength spectral energy distribution of the resulting 9 sources, using available archival data of Swift, GALEX, and Fermi satellites, confirming their nature. Through a simple one-zone synchrotron self-Compton model we est...

  15. Hard synchrotron BL Lacs: the case of 1ES 1101-232

    OpenAIRE

    Wolter, Anna; Ghisellini, Gabriele; Tagliaferri, Gianpiero; Tavecchio, Fabrizio; Caccianiga, Alessandro

    2000-01-01

    The bright X-ray selected BL Lac object 1ES1101--232 shows a flat X-ray spectrum, making it detectable with high statistics over the wide BeppoSAX energy range. We have observed it in two different epochs with BeppoSAX, and found a variation of the flux of about 30% that can be explained by a change in the spectral index above the synchrotron peak. We present here the data and infer limits on the strength of the magnetic field based on models of emission for High-frequency peaked BL Lacs.

  16. An asteroseismic study of the beta Cephei star 12 Lacertae: multisite spectroscopic observations, mode identification and seismic modelling

    CERN Document Server

    Desmet, M; Thoul, A; Zima, W; De Cat, P; Handler, G; Ilyin, I; Kambe, E; Krzesínski, J; Lehmann, H; Masuda, S; Mathias, P; Mkrtichian, D E; Telting, J; Uytterhoeven, K; Yang, S L S; Aerts, C

    2009-01-01

    We present the results of a spectroscopic multisite campaign for the beta Cephei star 12 (DD) Lacertae. Our study is based on more than thousand high-resolution high S/N spectra gathered with 8 different telescopes in a time span of 11 months. In addition we make use of numerous archival spectroscopic measurements. We confirm 10 independent frequencies recently discovered from photometry, as well as harmonics and combination frequencies. In particular, the SPB-like g-mode with frequency 0.3428 1/d reported before is detected in our spectroscopy. We identify the four main modes as (l1,m1) = (1, 1), (l2,m2) = (0, 0), (l3,m3) = (1, 0) and (l4,m4) = (2, 1) for f1 = 5.178964 1/d, f2 = 5.334224 1/d, f3 = 5.066316 1/d and f4 = 5.490133 1/d, respectively. Our seismic modelling shows that f2 is likely the radial first overtone and that the core overshooting parameter alpha_ov is lower than 0.4 local pressure scale heights.

  17. The gBL transport equations

    International Nuclear Information System (INIS)

    The transport equations arising from the ''generalized Balescu- Lenard'' (gBL) collision operator are obtained, and some of their properties examined. The equations contain neoclassical and turbulent transport as two special cases, having the same structure. The resultant theory offers potential explanation for a number of results not well understood, including the anomalous pinch, observed ratios of Q/ΓT on TFTR, and numerical reproduction of ASDEX profiles by a model for turbulent transport invoked without derivation, but by analogy to neoclassical theory. The general equations are specialized to consideration of a number of particular transport mechanisms of interest. 10 refs

  18. Object and Objective Lost?

    DEFF Research Database (Denmark)

    Lopdrup-Hjorth, Thomas

    2015-01-01

    of this organization-phobia, the paper argues that OT has become increasingly incapable of speaking about its core object. I show how organizations went from being conceptualized as entities of major importance to becoming theoretically deconstructed and associated with all kinds of ills. Through this history...

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

    Directory of Open Access Journals (Sweden)

    Hewitt Godfrey M

    2011-06-01

    Full Text Available Abstract 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

  20. The REX survey as a tool to test the beaming model for BL Lacs

    CERN Document Server

    Caccianiga, A; MacCacaro, T; Wolter, A; Gioia, I M

    1999-01-01

    In the context of the beaming model (BM) BL Lac and FR I radio galaxies are thought to be the same class of sources seen at different angles. If this picture is correct, we expect to find some transition objects with intermediate properties between the two classes. To date, this intermediate population of objects is missing, probably due to the limiting fluxes of the current X-ray/radio surveys and/or to the criteria used to separate BL Lacs from normal elliptical galaxies. As pointed out by Browne and Marcha (1993), the detection of the transition objects requires particular attention since the "weak" BL Lac nucleus is hidden by the light of the host elliptical galaxy. A useful criterion often used to assess the presence of a non-thermal source, in addition to the stellar emission of the host galaxy, is the Ca contrast at 4000 AA (K/sub 4000/). This quantity, which is defined as the relative depression of the spectrum across 4000 AA, is a typical feature observed in a "normal" elliptical galaxy; the samples ...

  1. Cuts and penalties: comment on "The clustering of ultra-high energy cosmic rays and their sources"

    OpenAIRE

    Tinyakov, P.; I. Tkachev(CERN)

    2003-01-01

    In a series of papers we have found statistically significant correlations between arrival directions of ultra-high energy cosmic rays and BL Lacertae objects. Recently, our calculations were partly repeated by Evans, Ferrer and Sarkar with different conclusions. We demonstrate that the criticism of Evans, Ferrer and Sarkar is incorrect. We also present the details of our method.

  2. On the Superluminal Motion of Radio-Loud AGNs

    Indian Academy of Sciences (India)

    Zhi-Bin Zhang; Yi-Zhen Zhang

    2011-03-01

    Apparent superluminal motion of different radio-loud AGNs are similarly related with beaming effect. The cosmological expanding effect would play no part in the superluminal motion of radio galaxies, BL Lacertae objects as well as quasars.Meanwhile, we confirm that estimates for apparent velocity app and Doppler boosting factor based on multi-wavelength combination and variability are comparable.

  3. Multiwavelength study of quiescent states of MRK 421 with unprecedented hard x-ray coverage provided by NuSTAR in 2013

    DEFF Research Database (Denmark)

    Baloković, M.; Paneque, D.; Madejski, G.;

    2016-01-01

    We present coordinated multiwavelength observations of the bright, nearby BL Lacertae object Mrk 421 taken in 2013 January-March, involving GASP-WEBT, Swift, NuSTAR, Fermi-LAT, MAGIC, VERITAS, and other collaborations and instruments, providing data from radio to very high energy (VHE) γ-ray band...

  4. Construction of a recombinant plasmid pGEX-Sj26GST of Schistosoma japonicum and expression in Escherichia coli BL21( DE3)

    Institute of Scientific and Technical Information of China (English)

    张丽

    2014-01-01

    Objective To construct and express a recombinant plasmid pGEX-Sj26GST of Schistosoma japonicum(Sj)in Escherichia coli(E.coli)BL21(DE3).Methods Total RNA was extracted from Sj adult worms by RNeasy Mini kit,26 kilodalton glutathione-S-transferases of Schistosoma japonicum(Sj26GST)antigen gene was amplified by real-time PCR(RT-PCR)from the total RNA,then cloned into a prokaryotic expression plasmid pGEX-1λT and transformed into E.coli BL21(DE3)to construct pGEX-Sj26GST;BL21(pGEX-

  5. Radium-226 in certified uranium reference ores DL-1a, BL-4a, DH-1a and BL-5

    International Nuclear Information System (INIS)

    Radium-226 radioactivity in uranium reference ores BL-4a and BL-5 and uranium-thorium reference ores DL-1a and DH-1a was determined in an interlaboratory program. Twelve of thirteen participants used certified radium solutions from the United States National Bureau of Standards (NBS) for calibration purposes. Recommended values of sup(226)Ra activity and associated parameters were calculated by statistical treatment of the results. In all cases, the recommended values are within 2 percent of activities predicted assuming secular equilibrium in the sup(238)U decay series. The recommended values for radium activity are 1.40, 15.5, 31.5 and 857 Bq/ for DL-1a, BL-4a, DH-1a and BL-5, respectively

  6. Dicty_cDB: FC-BL14 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available /dictycdb.biol.tsukuba.ac.jp/CSM/FC/FC-BL/FC-BL14Q.Seq.d/ Representative seq. ID ...FC-BL14Z (Link to Original site) Representative DNA sequence >FC-BL14 (FC-BL14Q) /CSM/FC/FC-BL/FC-BL14Q.Seq....SVWIGGSILASLSTFQQMWISKEEYDESGPSIVHRKCF *tiktsdesashtnkyi*mynnnki*lflmvvdlyptikkkkk Translated Amino Acid sequence (All Frames...DIRKDLYGNVVLSGGTTMFPGIADRMNK ELTALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWISKEEYDESGPSIVHRKCF *tiktsdesashtnkyi*...mynnnki*lflmvvdlyptikkkkk Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Va

  7. R-parity Conserving Minimal SUSY $B-L$ Model

    CERN Document Server

    Okada, Nobuchika

    2016-01-01

    We propose a simple gauged U(1)$_{B-L}$ extension of the minimal supersymmetric Standard Model (MSSM), where R-parity is conserved as usual in the MSSM. The global $B-L$ (baryon number minus lepton number) symmetry in the MSSM is gauged and three MSSM gauge-singlet chiral multiplets with a unit $B-L$ charge are introduced, ensuring the model free from gauge and gravitational anomalies. We assign an odd R-parity for two of the new chiral multiplets and hence they are identified with the right-handed neutrino superfields, while an even R-parity is assigned to the other one ($\\Phi$). The scalar component of $\\Phi$ plays the role of a Higgs field to break the U(1)$_{B-L}$ symmetry through its negative mass squared, which is radiatively generated by the renormalization group running of soft supersymmetry (SUSY) breaking parameters from a high energy. This radiative U(1)$_{B-L}$ symmetry breaking leads to its breaking scale being at the TeV naturally. Because of our novel R-parity assignment, three light neutrinos ...

  8. Testing the blazar sequence with the least luminous BL Lacs

    CERN Document Server

    Raiteri, Claudia M

    2015-01-01

    In a previous paper, we proposed a new method to select low-power BL Lacs (LPBLs) based on mid-infrared emission and flux contrast through the Ca II spectral break; that study led to the selection of a complete sample formed by 34 LPBLs with 0.05BL Lacs. We find that the ratios between the X-ray and radio luminosities range from ~20 to ~30000 and that the synchrotron peak frequencies span a wide energy interval, from log(nu_peak)~13.5 to ~20 [Hz]. This indicates a broad variety of SED shapes and a mixture of BL Lac flavors. Indeed, although the majority of our LPBLs are high-energy peaked BL Lacs (HBLs), we find that a quarter of them are low-energy peaked BL Lacs (LBLs), despite the fact that the sample is biased against the selection of LBLs. The analysis of the median LPBL SED con...

  9. Unifying the electroweak and B-L interactions

    CERN Document Server

    Dong, P V

    2015-01-01

    We argue that the gauge symmetry which includes SU(3)_L as a higher weak-isospin symmetry is manifestly given by SU(3)_C\\otimes SU(3)_L\\otimes U(1)_X\\otimes U(1)_N, where the last two factors determine the electric charge and B-L, respectively. This theory not only provides a consistent unification of the electroweak and B-L interactions, but also gives insights in dark matter, neutrino masses, and inflation. The dark matter belongs to a class of new particles that have wrong B-L numbers, and is stabilized due to a newly-realized W-parity as residual gauge symmetry. The B-L breaking field is important to define the W-parity, seesaw scales, and inflaton. Furthermore, the number of fermion generations and the electric charge quantization are explained naturally. We also show that the previous 3-3-1 models are only an effective theory as the B-L charge and the unitarity argument are violated. This work substantially generalizes our recently-proposed 3-3-1-1 model.

  10. An active state of the BL Lac Object Markarian 421 detected by INTEGRAL in April 2013

    CERN Document Server

    Pian, E; Fiocchi, M; Bazzano, A; Foschini, L; Tavecchio, F; Bianchin, V; Boissay, R; Castignani, G; Ferrigno, C; Raiteri, C M; Villata, M; Beckmann, V; D'Ammando, F; Hudec, R; Malaguti, G; Maraschi, L; Pursimo, T; Romano, P; Soldi, S; Stamerra, A; Treves, A; Ubertini, P; Vercellone, S; Walter, R

    2013-01-01

    (abridged) Multi-wavelength variability of blazars offers effective insight into the mechanisms through which energy is propagated from the center down the jet. In this context, we activated INTEGRAL observations of the blazar Markarian 421 in an active state on 16-21 April 2013, and complemented them with Fermi-LAT data. We obtained well sampled optical, soft and hard X-ray light curves that show the presence of two flares, the first one reaching a brighter maximum than the second one at X-rays. The average flux in the 20-100 keV range is 9.1e-11 cgs and the nuclear average apparent magnitude, corrected for Galactic extinction, is V ~ 12.2. In the time-resolved JEMX+IBIS spectra we see a change of spectral slope at an energy that correlates with flux, as expected in refreshed energy injections in a population of electrons that cool thereafter via synchrotron radiation. During the observation, the variability level increases monotonically from the optical to the hard X-rays, and the cross-correlation analysis...

  11. Fractal Property in the Light Curve of BL Lac Object S5 0716+714

    Indian Academy of Sciences (India)

    J. W. Ou; Y. G. Zheng

    2014-09-01

    In this paper, we compile the historical R-band data of S5 0716+714 from literature and obtain its fractal dimension by using a fractal method and then simulate the data with the Weierstrass–Mandelbrot (W–M) function. It is considered that the light curve has a fractal property.

  12. Majorana Dark matter with B+L gauge symmetry

    OpenAIRE

    Chao, Wei; Guo, Huai-Ke; Zhang, Yongchao

    2016-01-01

    We present a new model that extends the Standard Model (SM) with the local B+L symmetry, and point out that the lightest new fermion $\\zeta$, introduced to cancel anomalies and stabilized automatically by the B+L symmetry, can serve as the cold dark matter candidate. We study constraints on the model from Higgs measurements, electroweak precision measurements as well as the relic density and direct detections of the dark matter. Numerical results reveal that the pseudo-vector coupling of $\\ze...

  13. Von Blüten, Göttern und Gelehrten

    OpenAIRE

    Zotter, Astrid

    2013-01-01

    Der Sanskrittext Puṣpacintāmaṇi (PuCi) behandelt Blüten als Darbringungen (upacāra) im wichtigsten hinduistischen Verehrungsritual, der pūjā. In ca. 400 Strophen werden über 200 Namen von Blüten genannt und für verschiedene Gottheiten und pūjās als geeignete oder ungeeignete Gaben vorgeschrieben. Der Text ist eine Kompilation (Nibandha), in der die Inhalte aus 47 namentlich genannten Quellentexten referiert werden. Ziel der Dissertation ist es nicht nur, diesen Text, der 1966 zum ersten Ma...

  14. Kartlegging av marin bløtbunnsfauna - Metodeutvikling i hydrolittoralsonen

    OpenAIRE

    Haugen, Grethe Sundet

    2016-01-01

    Det er gjort få kvalitative undersøkelser på bløtbunnssamfunnet i hydrolittoralen i Norge. I denne studien ble artssammensetningen i littoralsonen fra tre forskjellige bløtbunnsstrender i Sør-Trøndelag undersøkt ved en enkel innsamlingsmetode. Innsamlingsmetoden hadde fokus på å observere og registrere fysiske miljøvariabler som bølgeeksponering og kornstørrelse, samt å observere å samle inn epi- og infauna som var tilstede i fjæra ved lavvann. Erfaringer fra felt- og laboratoriearbeidet har ...

  15. MULTIPLE OBJECTS

    Directory of Open Access Journals (Sweden)

    A. A. Bosov

    2015-04-01

    Full Text Available Purpose. The development of complicated techniques of production and management processes, information systems, computer science, applied objects of systems theory and others requires improvement of mathematical methods, new approaches for researches of application systems. And the variety and diversity of subject systems makes necessary the development of a model that generalizes the classical sets and their development – sets of sets. Multiple objects unlike sets are constructed by multiple structures and represented by the structure and content. The aim of the work is the analysis of multiple structures, generating multiple objects, the further development of operations on these objects in application systems. Methodology. To achieve the objectives of the researches, the structure of multiple objects represents as constructive trio, consisting of media, signatures and axiomatic. Multiple object is determined by the structure and content, as well as represented by hybrid superposition, composed of sets, multi-sets, ordered sets (lists and heterogeneous sets (sequences, corteges. Findings. In this paper we study the properties and characteristics of the components of hybrid multiple objects of complex systems, proposed assessments of their complexity, shown the rules of internal and external operations on objects of implementation. We introduce the relation of arbitrary order over multiple objects, we define the description of functions and display on objects of multiple structures. Originality.In this paper we consider the development of multiple structures, generating multiple objects.Practical value. The transition from the abstract to the subject of multiple structures requires the transformation of the system and multiple objects. Transformation involves three successive stages: specification (binding to the domain, interpretation (multiple sites and particularization (goals. The proposed describe systems approach based on hybrid sets

  16. PENURUNAN KADAR SIANIDA SINGKONG PAHIT PADA PROSES FERMENTASI CAIR BAKTERI BREVIBACTERIUM LACTOFERMENTEMUM BL-1M76

    Directory of Open Access Journals (Sweden)

    Suryana Purawisastra

    2012-11-01

    Full Text Available THE REDUCTION OF THE CYANIDE CONTENT OF BITIER CASSAVA BY THE PROCESS OF LIQUID FERMENTATION USING BREVIBACTERIUM LACTOFERMENTUM BL-1M76.Background: Cassava is one of the important source of carbohydrate in tropical countries, that easliy grows in any kind of soil. However, there is a kind of cassava containing cyanide substance, which is toxic for human consumption. This kind of cassava known as bitter cassava contains more starch, but it can't be used as food directly. Usually, people uses this cassava as raw material for producing starch known as 'tapioka' by the traditional method. The cyanide substance in cassava can be degraded by bacteria known as Brevibacterium sp R312 that is capable to degrade about 80% of the cyianide content in cassava, since this bacteria produces some enzymes namely E glucosidase, nitrilhydratase, and amidase, which degrade this cyanide substance. In our laboratory, has another strain of this bacteria, Brevibacterium fermentum BL-1M76, which Is not harmful and has potential capability in producing amino acid of lysine. Objectives: The study was conducted to investigate the potential of the bacteria Brevibacterium fermentum BL-1M76 in reducting of the cyanide substance of bitter cassava using the process of liquid fermentation. Materials and Methods: This experiment used four kinds of bitter cassava obtained from the Balai Penelitian Bioteknologi Tanaman Pangan, Departemen Pertanian (The Research Station of Biotechnology for Food Crops. Those cassavas are known as Adira II, Adria IV, 39.1.1 code, and 46.8 code. The liquid fermentation was conducted in the erlenmeyer flask 250 ml containing 10 ml of 10% cassava medium. The process of fermentation was done in two steps. The first step was to decide the maxmium volume and concentration cell of bacteria suspension, and the duration time of the incubation at the 28°C. The observation was done to the changes content of cyanide, and protein of the cassava medium due

  17. Object theatre

    DEFF Research Database (Denmark)

    Ryöppy, Merja; Heiberg, Andreas

    2015-01-01

    This paper investigates how four perspectives from Object Theatre can enhance interaction design in the early stages of a product design process. We propose these perspectives as a playful approach for designers to gain embodied understanding and perception of objects to enable new design...... possibilities to emerge. We present a study in which the Object Theatre approach is applied to redesign socially shared everyday products that are located in public places. This project demonstrates how Object Theatre offers a broad perspective form which to explore and present product interactions. In...

  18. The gravitational wave spectrum from cosmological B-L breaking

    International Nuclear Information System (INIS)

    Cosmological B-L breaking is a natural and testable mechanism to generate the initial conditions of the hot early universe. If B-L is broken at the grand unification scale, the false vacuum phase drives hybrid inflation, ending in tachyonic preheating. The decays of heavy B-L Higgs bosons and heavy neutrinos generate entropy, baryon asymmetry and dark matter and also control the reheating temperature. The different phases in the transition from inflation to the radiation dominated phase produce a characteristic spectrum of gravitational waves. We calculate the complete gravitational wave spectrum due to inflation, preheating and cosmic strings, which turns out to have several features. The production of gravitational waves from cosmic strings has large uncertainties, with lower and upper bounds provided by Abelian Higgs strings and Nambu-Goto strings, implying ΩGWh2 ∼ 10−13–10−8, much larger than the spectral amplitude predicted by inflation. Forthcoming gravitational wave detectors such as eLISA, advanced LIGO, ET, BBO and DECIGO will reach the sensitivity needed to test the predictions from cosmological B-L breaking

  19. Proteomic Analysis on Acetate Metabolism in Citrobacter sp. BL-4

    Directory of Open Access Journals (Sweden)

    Young-Man Kim, Sung-Eun Lee, Byeoung-Soo Park, Mi-Kyung Son, Young-Mi Jung, Seung-Ok Yang, Hyung-Kyoon Choi, Sung-Ho Hur, Jong Hwa Yum

    2012-01-01

    Full Text Available Mass production of glucosamine (GlcN using microbial cells is a worthy approach to increase added values and keep safety problems in GlcN production process. Prior to set up a microbial cellular platform, this study was to assess acetate metabolism in Citrobacter sp. BL-4 (BL-4 which has produced a polyglucosamine PGB-2. The LC-MS analysis was conducted after protein separation on the 1D-PAGE to accomplish the purpose of this study. 280 proteins were totally identified and 188 proteins were separated as acetate-related proteins in BL-4. Acetate was converted to acetyl-CoA by acetyl-CoA synthetase up-regulated in the acetate medium. The glyoxylate bypass in the acetate medium was up-regulated with over-expression of isocitrate lyases and 2D-PAGE confirmed this differential expression. Using 1H-NMR analysis, the product of isocitrate lyases, succinate, increased about 15 times in the acetate medium. During acetate metabolism proteins involved in the lipid metabolism and hexosamine biosynthesis were over-expressed in the acetate medium, while proteins involved in TCA cycle, pentose phosphate cycle and purine metabolism were down-regulated. Taken together, the results from the proteomic analysis can be applied to improve GlcN production and to develop metabolic engineering in BL-4.

  20. The gravitational wave spectrum from cosmological B-L breaking

    Energy Technology Data Exchange (ETDEWEB)

    Buchmueller, W.; Domcke, V.; Kamada, K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Schmitz, K. [Tokyo Univ., Kashiwa (Japan). Kavli IPMU (WPI)

    2013-05-15

    Cosmological B-L breaking is a natural and testable mechanism to generate the initial conditions of the hot early universe. If B-L is broken at the grand unification scale, the false vacuum phase drives hybrid inflation, ending in tachyonic preheating. The decays of heavy B-L Higgs bosons and heavy neutrinos generate entropy, baryon asymmetry and dark matter and also control the reheating temperature. The different phases in the transition from inflation to the radiation dominated phase produce a characteristic spectrum of gravitational waves. We calculate the complete gravitational wave spectrum due to inflation, preheating and cosmic strings, which turns out to have several features. The production of gravitational waves from cosmic strings has large uncertainties, with lower and upper bounds provided by Abelian Higgs strings and Nambu-Goto strings, implying {Omega}{sub GW}h{sup 2}{proportional_to}10{sup -13}-10{sup -8}, much larger than the spectral amplitude predicted by inflation. Forthcoming gravitational wave detectors such as eLISA, advanced LIGO and BBO/DECIGO will reach the sensitivity needed to test the predictions from cosmological B-L breaking.

  1. Probing classically conformal $B-L$ model with gravitational waves

    CERN Document Server

    Jinno, Ryusuke

    2016-01-01

    We study the cosmological history of the classical conformal $B-L$ gauge extension of the standard model, in which the physical scales are generated via the Coleman-Weinberg-type symmetry breaking. Especially, we consider the thermal phase transition of the U$(1)_{B-L}$ symmetry in the early universe and resulting gravitational-wave production. Due to the classical conformal invariance, the phase transition tends to be a first-order one with ultra-supercooling, which enhances the strength of the produced gravitational waves. We show that, requiring (1) U$(1)_{B-L}$ is broken after the reheating, (2) the $B-L$ gauge coupling does not blow up below the Planck scale, (3) the thermal phase transition completes in almost all the patches in the universe, the gravitational wave spectrum can be as large as $\\Omega_{\\rm GW} \\sim 10^{-8}$ at the frequency $f \\sim 0.01$-$1$Hz for some model parameters, and a vast parameter region can be tested by future interferometer experiments such as eLISA, LISA, BBO and DECIGO.

  2. The gravitational wave spectrum from cosmological B-L breaking

    Energy Technology Data Exchange (ETDEWEB)

    Buchmüller, W.; Domcke, V.; Kamada, K. [Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg (Germany); Schmitz, K., E-mail: buchmuwi@mail.desy.de, E-mail: valerie.domcke@desy.de, E-mail: kohei.kamada@desy.de, E-mail: kai.schmitz@ipmu.jp [Kavli IPMU (WPI), University of Tokyo, Kashiwa 277-8583 (Japan)

    2013-10-01

    Cosmological B-L breaking is a natural and testable mechanism to generate the initial conditions of the hot early universe. If B-L is broken at the grand unification scale, the false vacuum phase drives hybrid inflation, ending in tachyonic preheating. The decays of heavy B-L Higgs bosons and heavy neutrinos generate entropy, baryon asymmetry and dark matter and also control the reheating temperature. The different phases in the transition from inflation to the radiation dominated phase produce a characteristic spectrum of gravitational waves. We calculate the complete gravitational wave spectrum due to inflation, preheating and cosmic strings, which turns out to have several features. The production of gravitational waves from cosmic strings has large uncertainties, with lower and upper bounds provided by Abelian Higgs strings and Nambu-Goto strings, implying Ω{sub GW}h{sup 2} ∼ 10{sup −13}–10{sup −8}, much larger than the spectral amplitude predicted by inflation. Forthcoming gravitational wave detectors such as eLISA, advanced LIGO, ET, BBO and DECIGO will reach the sensitivity needed to test the predictions from cosmological B-L breaking.

  3. Temporal distributions, habitat associations and behaviour of the green lizard (Lacerta bilineata and wall lizard (Podarcis muralis on roads in a fragmented landscape in Western France

    Directory of Open Access Journals (Sweden)

    Roger Meek

    2014-12-01

    Full Text Available Observations of the green lizard (Lacerta bilineata and wall lizard (Podarcis muralis on roads in Western France indicated that basking close to the road edge was the predominant activity in L. bilineata but P. muralis mostly foraged. Spatial locations of road mortalities in both species reflected this with the median distances from the road edge greater in P. muralis. Temporal differences in road presence, based on mortality counts and those of live lizards, indicated significantly more lizards were present on roads during late summer and autumn, especially in P. muralis. A significant correlation was found between the monthly presence of live lizards and monthly road mortalities in P. muralis (r = 0.73 but not in L. bilineata (r = 0.64.  Numbers of L. bilineata found on roads bisecting low-density urban areas and roads bordered by hedgerows were higher than expected in relation to the occurrence of these habitats at roadsides. In P. muralis higher than expected numbers were found alongside low-density urban areas and roads bisecting woodland. Generally both species were less commonly seen on roads alongside agricultural areas with no hedgerow border.

  4. The 2003-4 multisite photometric campaign for the Beta Cephei and eclipsing star 16 (EN) Lacertae with an Appendix on 2 Andromedae, the variable comparison star

    CERN Document Server

    Jerzykiewicz, M; Daszynska-Daszkiewicz, J; Pigulski, A; Poretti, E; Rodriguez, E; Amado, P J; Kolaczkowski, Z; Uytterhoeven, K; Dorokhova, T N; Dorokhov, N I; Lorenz, D; Zsuffa, D; Kim, S -L; Bourge, P -O; Acke, B; De Ridder, J; Verhoelst, T; Drummond, R; Movchan, A I; Lee, J -A; Steslicki, M; Molenda-Zakowicz, J; Garrido, R; Kim, S -H; Michalska, G; Paparo, M; Antoci, V; Aerts, C

    2015-01-01

    A multisite photometric campaign for the Beta Cephei and eclipsing variable 16 Lacertae is reported. 749 h of high-quality differential photoelectric Stromgren, Johnson and Geneva time-series photometry were obtained with ten telescopes during 185 nights. After removing the pulsation contribution, an attempt was made to solve the resulting eclipse light curve by means of the computer program EBOP. Although a unique solution was not obtained, the range of solutions could be constrained by comparing computed positions of the secondary component in the Hertzsprung-Russell diagram with evolutionary tracks. For three high-amplitude pulsation modes, the uvy and the Geneva UBG amplitude ratios are derived and compared with the theoretical ones for spherical-harmonic degrees l <= 4. The highest degree, l = 4, is shown to be incompatible with the observations. One mode is found to be radial, one is l = 1, while in the remaining case l = 2 or 3. The present multisite observations are combined with the archival photo...

  5. Lacerta I and Cassiopeia III: Two luminous and distant Andromeda satellite dwarf galaxies found in the 3{\\pi} Pan-STARRS1 survey

    CERN Document Server

    Martin, Nicolas F; 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

    2013-01-01

    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 (M_V ~ -12) located at projected distances of 20.3{\\deg} and 10.5{\\deg} 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 (\\mu_0 ~ 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 alleviat...

  6. Ultrastructural features of the differentiating thyroid primordium in the sand lizard (Lacerta agilis L.) from the differentiation of the cellular cords to the formation of the follicular lumen.

    Science.gov (United States)

    Rupik, Weronika; Kowalska, Magdalena; Swadźba, Elwira; Maślak, Robert

    2016-04-01

    The differentiation of the thyroid primordium of lacertilian species is poorly understood. The present study reports on the ultrastructural analysis of the developing thyroid primordium in the sand lizard (Lacerta agilis) during the early stages of differentiation. The early thyroid primordium of sand lizard embryos was composed of cellular cords that contained single cells with a giant lipid droplet, which were eliminated by specific autophagy (lipophagy). The follicular lumens at the periphery of the primordium differentiated even before the division of the cellular cords. When the single cells within the cords started to die through paraptosis, the adjacent cells started to polarise and junctional complexes began to form around them. After polarisation and clearing up after the formation of the lumens, the cellular cords divided into definitive follicles. The cellular cords in the central part of the primordium started to differentiate later than those at the periphery. The cellular cords divided into presumptive follicles first and only later differentiated into definitive follicles. During this process, a population of centrally located cells was removed through apoptosis to form the lumen. Although the follicular lumen in sand lizard embryos is differentiated by cavitation similar to that in the grass snake, there were very important differences during the early stages of the differentiation of the cellular cords and the formation of the thyroid follicles. PMID:26966051

  7. Trusted Objects

    Energy Technology Data Exchange (ETDEWEB)

    CAMPBELL,PHILIP L.; PIERSON,LYNDON G.; WITZKE,EDWARD L.

    1999-10-27

    In the world of computers a trusted object is a collection of possibly-sensitive data and programs that can be allowed to reside and execute on a computer, even on an adversary's machine. Beyond the scope of one computer we believe that network-based agents in high-consequence and highly reliable applications will depend on this approach, and that the basis for such objects is what we call ''faithful execution.''

  8. Radar imaging of binary near-Earth asteroid (357439) 2004 BL86

    Science.gov (United States)

    Benner, Lance A. M.; Brozovic, Marina; Giorgini, Jon D.; Taylor, Patrick A.; Howell, Ellen S.; Busch, Michael W.; Nolan, Michael C.; Jao, Joseph S.; Lee, Clement G.; Ford, H. Alyson; Ghigo, Frank D.

    2015-11-01

    We report radar imaging of near-Earth asteroid 2004 BL86 obtained at Goldstone, Arecibo, Green Bank, and elements of the Very Long Baseline Array between 2015 January 26-31. 2004 BL86 approached within 0.0080 au on January 26, the closest known approach by any object with an absolute magnitude brighter than ~19 until 2027. Prior to the encounter, virtually nothing was known about its physical properties other than its absolute magnitude of 19, which suggested a diameter within a factor of two of 500 m. 2004 BL86 was a very strong radar target that provided an outstanding opportunity for radar imaging and physical characterization. Delay-Doppler images with range resolutions as fine as 3.75 m placed thousands of pixels on the object and confirmed photometric results reported by Pravec et al. (2015, CBET 4063) that 2004 BL86 is a binary system. During the observations, the asteroid moved more than 90 deg and provided a range of viewing geometries. The bandwidth was relatively narrow on Jan. 26, reached a maximum on Jan. 27, and then narrowed on Jan. 28, a progression indicating that the subradar latitude moved across the equator during those days. The images reveal a rounded primary with an equatorial diameter of ~350 m, evidence for ridges, possible boulders, and a pronounced angular feature ~100 m in diameter near one of the poles. Images from Jan. 26 show arcs of radar-bright pixels on the approaching and receding limbs that extend well behind the trailing edge in the middle of the echo. This is the delay-Doppler signature of an oblate shape seen at least a few tens of degrees off the equator. A rough estimate for the diameter of the secondary is ~70 m and its narrow bandwidth is consistent with the 14-h orbital period reported by Pravec et al. (2015). The images are suitable for 3D shape, pole, orbit, and mass estimation. The observations utilized new data taking equipment at Green Bank to receive X-band (8560 MHz, 3.5 cm) transmissions from the 70 m DSS-14

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

    Science.gov (United States)

    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.

  10. Fashion Objects

    DEFF Research Database (Denmark)

    Andersen, Bjørn Schiermer

    2009-01-01

    This article attempts to create a framework for understanding modern fashion phenomena on the basis of Durkheim's sociology of religion. It focuses on Durkheim's conception of the relation between the cult and the sacred object, on his notion of 'exteriorisation', and on his theory of the social...... symbol in an attempt to describe the peculiar attraction of the fashion object and its social constitution. However, Durkheim's notions of cult and ritual must undergo profound changes if they are to be used in an analysis of fashion. The article tries to expand the Durkheimian cult, radically enlarging...... of the enlargement of the cult into individual behaviour....

  11. Setting Objectives

    Science.gov (United States)

    Elkins, Aaron J.

    1977-01-01

    The author questions the extent to which educators have relied on "relevance" and learner participation in objective-setting in the past decade. He describes a useful approach to learner-oriented evaluation in which content relevance was not judged by participants until after they had been exposed to it. (MF)

  12. RISING beamline (BL28XU) for rechargeable battery analysis

    International Nuclear Information System (INIS)

    The BL28XU beamline, dedicated to rechargeable battery analysis, is described. The newly installed BL28XU beamline at SPring-8 is dedicated to in situ structural and electronic analysis of rechargeable batteries. It supports the time range (1 ms to 100 s) and spatial range (1 µm to 1 mm) needed for battery analysis. Electrochemical apparatus for battery charging and discharging are available in experimental hutches and in a preparation room. Battery analysis can be carried out efficiently and effectively using X-ray diffraction, X-ray absorption fine-structure analysis and hard X-ray photoelectron spectroscopy. Here, the design and performance of the beamline are described, and preliminary results are presented

  13. Majorana Dark matter with B+L gauge symmetry

    CERN Document Server

    Chao, Wei; Zhang, Yongchao

    2016-01-01

    We present a new model that extends the Standard Model (SM) with the local B+L symmetry, and point out that the lightest new fermion $\\zeta$, introduced to cancel anomalies and stabilized automatically by the B+L symmetry, can serve as the cold dark matter candidate. We study constraints on the model from Higgs measurements, electroweak precision measurements as well as the relic density and direct detections of the dark matter. Numerical results reveal that the pseudo-vector coupling of $\\zeta$ with $Z$ and the Yukawa coupling with the SM Higgs are highly constrained by the latest results of LUX, while there are viable parameter space that could satisfy all the constraints and give testable predictions.

  14. Asymmetric Gepner models III. B-L lifting

    Energy Technology Data Exchange (ETDEWEB)

    Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); IMAPP, Radboud Universiteit, Nijmegen (Netherlands)

    2011-06-21

    In the same spirit as heterotic weight lifting, B-L lifting is a way of replacing the superfluous and ubiquitous U(1){sub B-L} with something else with the same modular properties, but different conformal weights and ground state dimensions. This method works in principle for all variants of (2,2) constructions, such as orbifolds, Calabi-Yau manifolds, free bosons and fermions and Gepner models, since it only modifies the universal SO(10)xE{sub 8} part of the CFT. However, it can only yield chiral spectra if the 'internal' sector of the theory provides a simple current of order 5. Here we apply this new method to Gepner models. Including exceptional invariants, 86 of them have the required order 5 simple current, and 69 of these yield chiral spectra. Three family spectra occur abundantly.

  15. Asymmetric Gepner Models III. B-L Lifting

    CERN Document Server

    Gato-Rivera, B

    2010-01-01

    In the same spirit as heterotic weight lifting, B-L lifting is a way of replacing the superfluous and ubiquitous U(1)_{B-L} with something else with the same modular properties, but different conformal weights and ground state dimensions. This method works in principle for all variants of (2,2) constructions, such as orbifolds, Calabi-Yau manifolds, free bosons and fermions and Gepner models, since it only modifies the universal SO(10) x E_8 part of the CFT. However, it can only yield chiral spectra if the ``internal" sector of the theory provides a simple current of order 5. Here we apply this new method to Gepner models. Including exceptional invariants, 86 of them have the required order 5 simple current, and 69 of these yield chiral spectra. Three family spectra occur abundantly.

  16. Period doubling and Blazhko modulation in BL Herculis hydrodynamic models

    CERN Document Server

    Smolec, R

    2012-01-01

    We present the hydrodynamic BL Herculis-type models which display a long-term modulation of pulsation amplitudes and phases. The modulation is either strictly periodic or it is quasi-periodic, with the modulation period and modulation pattern varying from one cycle to the other. Such behaviour has not been observed in any BL Her variable so far, however, it is a common property of their lower luminosity siblings - RR Lyrae variables showing the Blazhko effect. These models provide a support for the recent mechanism proposed by Buchler & Kollath to explain this still mysterious phenomenon. In their model, a half-integer resonance that causes the period doubling effect, discovered recently in the Blazhko RR Lyrae stars, is responsible for the modulation of the pulsation as well. Although our models are more luminous than is appropriate for RR Lyrae stars, they clearly demonstrate, through direct hydrodynamic computation, that the mechanism can indeed be operational. Of great importance are models which show...

  17. 普通小麦-簇毛麦易位系T6BS·6BL-2VS的选育%Identification of Triticum aestivum-Haynaldia villosa Translocation Line T6BS·6BL-2VS

    Institute of Scientific and Technical Information of China (English)

    陈全战; 张边江; 周峰; 吴梅; 李华春

    2008-01-01

    [Objective] The aim of experiment was to provide a new germplasm for wheat breeding by further using desirable genes in 2V chromosome of Haynaldia villosa.[Method] Through hybridization between common wheat(Triticum aestivum)-Haynaldia villosa disomic substitution line and common wheat Nonglin26-3C chromosome of Aegilops triuncialis disomic addition line, the analysis methods such as chromosome C-banding, genomic in situ hybridization and molecular marker technique were comprehensively applied and combined characters investigation.[Result] The wheat-Haynaldia villosa translocation line(T6BS·6BL-2VS) was selected from hybrid progenies to conduct characters investigation,which found some bristles on glume ridge of T6BS·6BL-2VS.[Conclusion] The translocation line induced by gametocidal chromosome was a small segment translocation line and the gene of bristle on glume ridge of Haynaldia villosa was located between the middle and the terminal of 2VS.

  18. Period of Light Variability in BL Lac ON 231

    Indian Academy of Sciences (India)

    Xu Yun Bing; Zhang Hao Jing; Zhang Xiong; Mao Wei Ming; Dong Fu Tong

    2011-03-01

    In this paper, the authors have compiled the data of about 100 years in B-band of the BL Lac ON 231 and used this database to analyze periodicity signals in the optical light curve. Two different methods were applied: the wavelet analysis and the Discrete Correlation Function (DCF) method. We revealed the existence of periods of 13.5 years in the source variability.

  19. Objective thermomechanics

    OpenAIRE

    Fülöp, Tamás

    2015-01-01

    An irreversible thermodynamical theory of solids is presented where the kinematic quantities are defined in an automatically objective way. Namely, auxiliary elements like reference frame, reference time and reference configuration are avoided by formulating the motion of the continuum on spacetime directly. Solids are distinguished from fluids by possessing not only an instantaneous metric tensor but also a relaxed metric. The elastic state variable is defined through comparing these two met...

  20. Objective Morality

    OpenAIRE

    Allott, Robin

    1991-01-01

    An objective basis for morality can be found in an evolutionary account of its origin and development. Morality is a key factor in the success of human groups in competition or co-existence with each other.A group's moral code represents an increasingly rational pattern of behaviour derived from the collective experience of the group handed down from generation to generation. Group selection is a controversial idea for animal evolution but it is inescapable in accounting for human evolution u...

  1. Distinct Transcriptional Signatures of Bone Marrow-Derived C57BL/6 and DBA/2 Dendritic Leucocytes Hosting Live Leishmania amazonensis Amastigotes

    OpenAIRE

    Giraud, Emilie; Lecoeur, Hervé; Soubigou, Guillaume; Coppée, Jean-Yves; Milon, Geneviève; Prina, Eric; Lang, Thierry

    2012-01-01

    Background/Objectives The inoculation of a low number (104) of L. amazonensis metacyclic promastigotes into the dermis of C57BL/6 and DBA/2 mouse ear pinna results in distinct outcome as assessed by the parasite load values and ear pinna macroscopic features monitored from days 4 to 22-phase 1 and from days 22 to 80/100-phase 2. While in C57BL/6 mice, the amastigote population size was increasing progressively, in DBA/2 mice, it was rapidly controlled. This latter rapid control did not preven...

  2. Acupuncture of Weizhong (BL 40) and Zusanli (ST 36) on the study of brain function by PET/CT imaging

    International Nuclear Information System (INIS)

    Objective: To explore the correlation between acupuncture of the points and certain functional areas of brain by PET/CT imaging. Methods: Twelve healthy volunteers were acupunctured separately in the point Weizhong (BL 40, right leg) and Zusanli(ST 36, right leg), and 5 consecutive PET/CT images were taken, statistical parameter map (SPM) paired t-test was analyzed between the different activated brain PET/CT imagings. Results: Changes of PET/CT imaging were found in acupuncture of the point Weizhong (BL 40) and Zusanli(ST 36) in 12 healthy volunteers. High metabolic areas were demonstrated in multiple brain regions, the data of two groups had significant difference between 2 points (t>4.03, P< 0.01). Conclusion: Acupuncturing the different point resulted activation of the glucose metabolism in different brain areas. (authors)

  3. Brain plasticity and cognitive functions after ethanol consumption in C57BL/6J mice.

    Science.gov (United States)

    Stragier, E; Martin, V; Davenas, E; Poilbout, C; Mongeau, R; Corradetti, R; Lanfumey, L

    2015-01-01

    Acute or chronic administrations of high doses of ethanol in mice are known to produce severe cognitive deficits linked to hippocampal damage. However, we recently reported that chronic and moderate ethanol intake in C57BL/6J mice induced chromatin remodeling within the Bdnf promoters, leading to both enhanced brain-derived neurotrophic factor (BDNF) expression and hippocampal neurogenesis under free-choice protocol. We performed here a series of cellular and behavioral studies to analyze the consequences of these modifications. We showed that a 3-week chronic free-choice ethanol consumption in C57BL/6J mice led to a decrease in DNA methylation of the Bdnf gene within the CA1 and CA3 subfields of the hippocampus, and upregulated hippocampal BDNF signaling pathways mediated by ERK, AKT and CREB. However, this activation did not affect long-term potentiation in the CA1. Conversely, ethanol intake impaired learning and memory capacities analyzed in the contextual fear conditioning test and the novel object recognition task. In addition, ethanol increased behavioral perseveration in the Barnes maze test but did not alter the mouse overall spatial capacities. These data suggested that in conditions of chronic and moderate ethanol intake, the chromatin remodeling leading to BDNF signaling upregulation is probably an adaptive process, engaged via epigenetic regulations, to counteract the cognitive deficits induced by ethanol. PMID:26670281

  4. BL_Wiener Denoising Method for Removal of Speckle Noise in Ultrasound Image

    Directory of Open Access Journals (Sweden)

    Suhaila Sari

    2015-02-01

    Full Text Available Medical imaging techniques are extremely important tools in medical diagnosis. One of these important imaging techniques is ultrasound imaging. However, during ultrasound image acquisition process, the quality of image can be degraded due to corruption by speckle noise. The enhancement of ultrasound images quality from the 2D ultrasound imaging machines is expected to provide medical practitioners more reliable medical images in their patients’ diagnosis. However, developing a denoising technique which could remove noise effectively without eliminating the image’s edges and details is still an ongoing issue. The objective of this paper is to develop a new method that is capable to remove speckle noise from the ultrasound image effectively. Therefore, in this paper we proposed the utilization of Bilateral Filter and Adaptive Wiener Filter (BL_Wiener denoising method for images corrupted by speckle noise. Bilateral Filter is a non-linear filter effective in removing noise, while Adaptive Wiener Filter balances the tradeoff between inverse filtering and noise smoothing by removing additive noise while inverting blurring. From our simulation results, it is found that the BL_Wiener method has improved between 0.89 [dB] to 3.35 [dB] in terms of PSNR for test images in different noise levels in comparison to conventional methods.

  5. Redshift measurement of the BL-Lac gamma-ray blazar PKS 1424+240

    CERN Document Server

    Rovero, A C; Pichel, A; Muriel, H

    2015-01-01

    PKS 1424+240 is a BL-Lac blazar with unknown redshift detected at high-energy gamma rays by Fermi-LAT with a hard spectrum. It was first detected at very-high-energy by VERITAS and latter confirmed by MAGIC. Attempts to find limits on its redshift include three estimations by modeling gamma-ray observations, and one obtained by analyzing Lyb and Lyg absorption lines observed in the far-UV spectra (from HST/COS) caused by absorbing gas along the line of sight. They allowed to constrain the redshift range to 0:6BL-Lac objects are difficult to achieve. We have found that redshift of blazars can be determined by its association to a galaxy group or cluster. To explore this possibility for PKS 1424+240, we have carried out spectroscopic measurements with the Gemini North telescope of galaxies in its field of view...

  6. Hydrogeologic Characterization of the U-3bl Collapse Zone

    International Nuclear Information System (INIS)

    The U-3bl collapse crater was formed by an underground nuclear test in August 1962. This crater and the adjoining U-3ax crater were subsequently developed and used as a bulk low-level radioactive waste disposal cell (U-3ax/bl), which is part of the Area 3 Radioactive Waste Management Site at the Nevada Test Site (NTS). Various investigations have been conducted to assess the hydrogeologic characteristics and properties in the vicinity of the U-3ax/bl waste disposal cell. This report presents data from one of these investigations, conducted in 1996. Also included in this report is a review of pertinent nuclear testing records, which shows that the testing operations and hydrogeologic setting of the U-3ax/bl site were typical for the period and location of testing. Borehole U-3bl-D2 is a 45-degree-angle hole drilled from the edge of the crater under the waste cell to intercept the U-3bl collapse zone, the disturbed alluvium between the crater (surface collapse sink) and the nuclear test cavity. A casing-advance system with an air percussion hammer was used to drill the borehole, and air was used as the drilling fluid. Properties of the U-3bl crater collapse zone were determined from cores collected within the interval, 42.1 to 96.6 meters (138 to 317 feet) below the ground surface. Selected core samples were analyzed for particle density, particle size, bulk density, water retention, hydraulic conductivity, water content, water potential, chloride, carbonate, stable isotopes, and tritium. Physical and hydraulic properties were typical of alluvial valley sediments at the NTS. No visual evidence of preferential pathways for water transport was observed in the core samples. Soil parameters showed no trends with depth. Volumetric water content values ranged from 0.08 to 0.20 cubic meters per cubic meter, and tended to increase with depth. Water-retention relations were typical for soils of similar texture. Water potentials ranged from -1.9 MegaPascals at a depth of 42

  7. Quantum Objects

    CERN Document Server

    Mansouri, Alireza; Karbasizadeh, Amir Ehsan

    2013-01-01

    In this paper, we suggest an alternative interpretation for the quantum state vector, which, by considering temporal parts for physical objects, aims to give an intelligible account of measurement problem in quantum mechanics. We examine the capacity of this interpretation as for explaining three measurement problems: the problem of outcome, the problem of statistics and the problem of effect. We argue that, this interpretation of the state vector, while providing a satisfactory account, as rationally plausible as its rivals, for the measurement problem, shows yet another limitation of our perceptual experience, i.e. our inability to perceive unsharp reality.

  8. Wow!: objects

    OpenAIRE

    Freitas, Paulo Sérgio da Silva

    2008-01-01

    Nowadays computers have advanced beyond the desktop into many parts of everyday life and objects. To achieve this we have to make the computer invisible, and making a computer invisible is not a matter of size of the hardware, it’s all about how the human perceives the computer. To make this possible, the interaction with the computer has to be done in an alternative way, such that the user doesn’t notice the usual computer interfaces (mouse and keyboard) when using it. Therefore this t...

  9. Objective thermomechanics

    CERN Document Server

    Fülöp, Tamás

    2015-01-01

    An irreversible thermodynamical theory of solids is presented where the kinematic quantities are defined in an automatically objective way. Namely, auxiliary elements like reference frame, reference time and reference configuration are avoided by formulating the motion of the continuum on spacetime directly, utilizing the Weyl-Matolcsi description of spacetime. This restricts the range of definable kinematic quantities heavily. Solids are distinguished from fluids by possessing not only an instantaneous metric tensor but a relaxed metric, too, that represents the natural geometric structure of the solid. The comparison of the instantaneous metric to the relaxed one is the basis of the definition of the elastic state variable, the elastic deformedness tensor. Thermal expansion is conceived as the temperature dependence of the relaxed metric. As opposed to this reversible type of change, plasticity means an irreversible change in the relaxed metric, and is describable via a plastic change rate tensor. The relat...

  10. Ozone measurement in EXAFS beam line BL-08 of INDUS-2

    International Nuclear Information System (INIS)

    Ozone measurement in experimental hutch of Extended X-ray Absorption Fine Structure (EXAFS) beam line (BL-08) of INDUS-2 is carried out with the objectives of measuring ozone build-up profile at various locations inside the hutch, to check the effectiveness of the existing exhaust blower used to remove the ozone from the hutch and to determine the ozone decay time to reach the safe limit of 0.1 ppm. The results show that the ozone level is less than 0.1 ppm in all measured locations. This paper describes the methodology, experimental set-up and the results of the experiment done in June 2010 at RRCAT. (author)

  11. Capric Acid Reduces Body Weight in C57BL/6J Mice Fed a High Fat Diet

    Institute of Scientific and Technical Information of China (English)

    Ying-hua LIU; Yong ZHANG; Qing XU; Xin-sheng ZHANG; Jin WANG; Xiao-ming YU; Xue-yan YANG; Chang-yong XUE

    2014-01-01

    Objective To compare the body weight reducing effect of two medium-chain fatty acids (MCFA), capric acid and caprylic acid, and the potential underlying mechanisms in C57BL/6J mice fed a high fat diet.Methods Obese C57BL/6J mice were developed on a high-fat diet containing 2% caprylic acid (C8:0), 2% capric acid (C10:0), or 2% oleic acid (C18:1). Body weight and diet intake were monitored twice a week. After 8 weeks of feeding, body fat composition and the protein or mRNA expression of lipolysis-related genes in the white adipose tissue (WAT) were analyzed.Results In the capric acid group, significant reductions were observed in body weight gain, Lee's index, BMI, and epididymal adipose tissue weight, while increased levels of adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), cyclic adenosine monophosphate (cAMP) and beta 3 adrenergic receptor (β3-AR) were found in the adipose tissue, compared to the oleic acid group. No significant differences in these parameters were found between caprylic acid and oleic acid groups.Conclusion Capric acid, but not caprylic acid, is effective in reducing body weight in obese C57BL/6J mice,possibly due to up-regulation of β3-AR, ATGL, and HSL in WAT.

  12. The labeling of C57BL/6j derived embryonic stem cells with enhanced green fluorescent protein

    Institute of Scientific and Technical Information of China (English)

    滕路; 张崇本; 尤洁芳; 尚克刚; 顾军

    2003-01-01

    Objective To labele MESPU35, a embryonic stem (ES) cell line derived from C57BL/6j mouse, with enhanced green fluorescent protein (EGFP) for further application.Methods The EGFP gene was controlled by the hybrid CA promoter/enhancer (CMV enhancer/ chicken beta-actin promoter/ beta-actin intron) to construct the vector of the transgene, pCA-EGFP. The vector was transfected into MESPU35 by electroporation.Results We generated EGFP expressing ES cells demonstrating normal properties. The green fluorescence of EGFP expressing cells was maintained in propagation of the ES cells for more than 30 passages as well as in differentiated cells. Cultured in suspension, the "green" ES cells aggregated, and formed embryoid bodies maintaining the green fluorescence at varying developmental stages. The "green" embryoid bodies could expand and differentiate into various types of cells, exhibiting ubiquitous green fluorescence. Conclusions The hybrid CA promoter/enhancer used to control the EGFP expressing ES cells, resulted in more intense and ubiquitous activity. The EGFP transfected cells yield bright green fluorescence, which can be visualized in real time and in situ. In addition, the ES cells, MESPU35, are derived from C57BL/6j mice, which are the most widely used in oncology, physiology and genetics. Compared to 129 substrains, C57BL/6j mice avoid a number of potential problems apparent in the other strains.

  13. Long-term artificial sweetener acesulfame potassium treatment alters neurometabolic functions in C57BL/6J mice.

    Directory of Open Access Journals (Sweden)

    Wei-na Cong

    Full Text Available With the prevalence of obesity, artificial, non-nutritive sweeteners have been widely used as dietary supplements that provide sweet taste without excessive caloric load. In order to better understand the overall actions of artificial sweeteners, especially when they are chronically used, we investigated the peripheral and central nervous system effects of protracted exposure to a widely used artificial sweetener, acesulfame K (ACK. We found that extended ACK exposure (40 weeks in normal C57BL/6J mice demonstrated a moderate and limited influence on metabolic homeostasis, including altering fasting insulin and leptin levels, pancreatic islet size and lipid levels, without affecting insulin sensitivity and bodyweight. Interestingly, impaired cognitive memory functions (evaluated by Morris Water Maze and Novel Objective Preference tests were found in ACK-treated C57BL/6J mice, while no differences in motor function and anxiety levels were detected. The generation of an ACK-induced neurological phenotype was associated with metabolic dysregulation (glycolysis inhibition and functional ATP depletion and neurosynaptic abnormalities (dysregulation of TrkB-mediated BDNF and Akt/Erk-mediated cell growth/survival pathway in hippocampal neurons. Our data suggest that chronic use of ACK could affect cognitive functions, potentially via altering neuro-metabolic functions in male C57BL/6J mice.

  14. Long-term artificial sweetener acesulfame potassium treatment alters neurometabolic functions in C57BL/6J mice.

    Science.gov (United States)

    Cong, Wei-na; Wang, Rui; Cai, Huan; Daimon, Caitlin M; Scheibye-Knudsen, Morten; Bohr, Vilhelm A; Turkin, Rebecca; Wood, William H; Becker, Kevin G; Moaddel, Ruin; Maudsley, Stuart; Martin, Bronwen

    2013-01-01

    With the prevalence of obesity, artificial, non-nutritive sweeteners have been widely used as dietary supplements that provide sweet taste without excessive caloric load. In order to better understand the overall actions of artificial sweeteners, especially when they are chronically used, we investigated the peripheral and central nervous system effects of protracted exposure to a widely used artificial sweetener, acesulfame K (ACK). We found that extended ACK exposure (40 weeks) in normal C57BL/6J mice demonstrated a moderate and limited influence on metabolic homeostasis, including altering fasting insulin and leptin levels, pancreatic islet size and lipid levels, without affecting insulin sensitivity and bodyweight. Interestingly, impaired cognitive memory functions (evaluated by Morris Water Maze and Novel Objective Preference tests) were found in ACK-treated C57BL/6J mice, while no differences in motor function and anxiety levels were detected. The generation of an ACK-induced neurological phenotype was associated with metabolic dysregulation (glycolysis inhibition and functional ATP depletion) and neurosynaptic abnormalities (dysregulation of TrkB-mediated BDNF and Akt/Erk-mediated cell growth/survival pathway) in hippocampal neurons. Our data suggest that chronic use of ACK could affect cognitive functions, potentially via altering neuro-metabolic functions in male C57BL/6J mice. PMID:23950916

  15. Ortsgedächtnis für Blütenpositionen bei der Blütenfledermaus Glossophaga soricina

    OpenAIRE

    Stich, Kai Petra

    2004-01-01

    Die Nahrungssuche ist für Tiere kein triviales Verhaltensproblem. Nahrung ist im Habitat eines Tieres selten homogen verteilt, wobei räumliche Heterogenität unter anderem durch das zeitliche Muster der Ressourcenerneuerung und durch die Nahrungssuche der Tiere selbst verursacht wird. Besonders bei sich rasch erneuernden Nahrungsquellen wie z.B. Blütennektar ist es für viele Tiere von Vorteil, sich einerseits den Ort dieser Quellen zu merken, um wieder dorthin zurückzukehren, andererseits jedo...

  16. Mass spectrum of the minimal SUSY B-L model

    CERN Document Server

    O'Leary, Ben; Staub, Florian

    2011-01-01

    The origin of R-parity in supersymmetric models can be explained if \\BL is part of the gauge group. We discuss the mass spectrum of the minimal $U(1)_Y \\times U(1)_{B-L}$ model based on a GUT implementation using CMSSM-like boundary conditions. Here we focus in particular on the Higgs and neutralino sectors in this class of models. While the neutralinos can have masses as low as 100 GeV, we show that the requirement of being consistent with existing bounds on the $Z'$ implies that in general the sfermions have masses in the multi-TeV range. In the extended Higgs sector we show the existence of a second light state which, however, will be difficult to observe, while having at the same time a SM-like Higgs in a mass range close to 120 GeV. Moreover, we propose a set of benchmark scenarios for phenomenological studies. On the technical side we demonstrate that gauge kinetic mixing effects can be quite important, affecting in particular the Higgs and the neutralino sectors. Not only can they shift the mass of the...

  17. Exploring the magnetic field configuration in BL Lac using GMVA

    CERN Document Server

    Rani, B; Hodgson, J; Koyama, S; Zensus, J A; Fuhrmann, L; Marscher, A P; Jorstad, S G

    2016-01-01

    The high radio frequency polarization imaging of non-thermal emission from active galactic nuclei (AGN) is a direct way to probe the magnetic field strength and structure in the immediate vicinity of supermassive black holes (SMBHs) and is crucial in testing the jet-launching scenario. To explore the the magnetic field configuration at the base of jets in blazars, we took advantage of the full polarization capabilities of the Global Millimeter VLBI Array (GMVA). With an angular resolution of $\\sim$50 micro-arcseconds ($\\mu$as) at 86 GHz, one could resolve scales up to $\\sim$450 gravitational radii (for a 10$^9$ solar mass black hole at a redshift of 0.1). We present here the preliminary results of our study on the blazar BL~Lac. Our results suggest that on sub-mas scales the core and the central jet of BL Lac are significantly polarized with two distinct regions of polarized intensity. We also noted a great morphological similarity between the 7mm/3mm VLBI images at very similar angular resolution.

  18. The estimations of four basic parameters for gamma-ray loud blazars

    Institute of Scientific and Technical Information of China (English)

    Jun-Hui Fan; Yu-Hai Yuan; Yi Liu; Jing-Yi Zhang; Yi-Ping Qin; Hua Liu; Yong Huang; Jiang-He Yang; Hong-Guang Wang; Jiang-Shui Zhang

    2009-01-01

    The method used in our previous papers is adopted to estimate four basic pa-rameters (the central black hole mass (M), the boosting factor (or Doppler factor) (δ), the (d)) for 59 γ-ray loud blazars (20 BL Lacertae objects and 39 fiat spectrum radio quasars).The central black hole masses estimated for this sample are in a range of from 107 M⊙to 109 M⊙. In the case of black hole mass, there is no clear difference between BL Lacertae objects and flat spectrum radio quasars, which is consistent with the previous results sug-gesting that the central black hole masses do not play an important role in the evolutionary sequence of blazars.

  19. The estimations of four basic parameters for gamma-ray loud blazars

    International Nuclear Information System (INIS)

    The method used in our previous papers is adopted to estimate four basic parameters (the central black hole mass (M), the boosting factor (or Doppler factor) (δ), the propagation angle (Φ) and the distance along the axis to the site of the γ-ray production (d)) for 59 γ-ray loud blazars (20 BL Lacertae objects and 39 flat spectrum radio quasars). The central black hole masses estimated for this sample are in a range of from 107 Mo-dot to 109 Mo-dot. In the case of black hole mass, there is no clear difference between BL Lacertae objects and flat spectrum radio quasars, which is consistent with the previous results suggesting that the central black hole masses do not play an important role in the evolutionary sequence of blazars.

  20. Testing the Black Hole No-hair Theorem with OJ287

    Czech Academy of Sciences Publication Activity Database

    Valtonen, M.J.; Mikkola, S.; Lehto, H.J.; Gopakumar, A.; Hudec, René; Poledníková, J.

    2011-01-01

    Roč. 742, č. 1 (2011), 22/1-22/12. ISSN 0004-637X R&D Projects: GA ČR GA205/08/1207 Grant ostatní: GA ČR(CZ) GA102/09/0997; GA MŠk(CZ) ME09027 Institutional research plan: CEZ:AV0Z10030501 Keywords : black hole physics * BL Lacertae objects Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 6.024, year: 2011

  1. Measuring the spin of the primary black hole in OJ287

    Czech Academy of Sciences Publication Activity Database

    Valtonen, M.J.; Mikkola, S.; Merritt, D.; Gopakumar, A.; Lehto, H.J.; Hyvönen, L. T.; Rampadarath, H.; Saunders, R.; Bašta, Milan; Hudec, R.

    2010-01-01

    Roč. 709, č. 2 (2010), s. 725-732. ISSN 0004-637X R&D Projects: GA ČR GA205/08/1207 Grant ostatní: GA ČR(CZ) GA102/09/0997 Institutional research plan: CEZ:AV0Z10030501 Keywords : black hole physics * BL Lacertae objects * individual (OJ287) Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 7.436, year: 2010

  2. Influence of Reinforcement Schedule on Ethanol Consumption Patterns in Non-Food Restricted Male C57BL/6J Mice

    OpenAIRE

    Ford, Matthew M.; Fretwell, Andrea M.; Mark, Gregory P.; Finn, Deborah A.

    2007-01-01

    Ethanol reinforcement should ideally be evaluated in animals that are not food deprived to ensure that the motivation behind its consumption is pharmacological, and not caloric, in nature. The objective of this work was to assess the influence of reinforcement schedule on ethanol intake in non-deprived mice. Male C57BL/6J mice were trained to respond on an ethanol-reinforced lever on a fixed ratio (FR) 4 reinforcement schedule for 10% ethanol (10E). The appetitive and consummatory phases were...

  3. Cornu cervi pantotrichum Pharmacopuncture Solution Facilitate Hair Growth in C57BL/6 Mice

    Directory of Open Access Journals (Sweden)

    Seon-Yong Lee

    2016-06-01

    Full Text Available Objectives: Cornu cervi pantotrichum (CCP has been widely used in Korean and China, as an anti-fatigue, anti-aging, and tonic agent to enhance the functions of the reproductive and the immune systems. Because CCP has various growth factors that play important roles in the development of hair follicles, we examined whether CCP pharmacopuncture solution (CCPPS was capable of promoting hair growth in an animal model. Methods: One day after hair depilation, CCPPS were topically applied to the dorsal skin of C57BL/6 mice once a day for 15 days. Hair growth activity was evaluated by using macro- and microscopic observations. Dorsal skin tissues were stained with hematoxylin and eosin. Expressions of bromodeoxyuridine (BrdU, proliferating cell nuclear antigen (PCNA, and fibroblast growth factor (FGF-7 were examined by using immunohistochemical staining. A reverse transcription polymerase chain reaction (RT-PCR analysis was also conducted to measure the messenger RNA (mRNA expression of FGF-7. Results: CCPPS induced more active hair growth than normal saline. Histologic analysis showed enlargement of the dermal papilla, elongation of the hair shaft, and expansion of hair thickness in CCPPS treated mice, indicating that CCPPS effectively induced the development of anagen. CCPPS treatment markedly increased the expressions of BrdU and PCNA in the hair follicles of C57BL/6 mice. In addition, CCPPS up regulated the expression of FGF-7, which plays an important role in the development of hair follicles. Conclusion: These results reveal that CCPPS facilitates hair re-growth by proliferation of hair follicular cells and up-regulation of FGF-7 and suggest that CCPPS can potentially be applied as an alternative treatment for patients with alopecia.

  4. Dermal exposure to tannery effluent causes neurobehavioral changes in C57Bl/6J and Swiss mice.

    Science.gov (United States)

    da Silva, Wellington Alves Mizael; Mendes, Bruna de Oliveira; Guimarães, Abraão Tiago Batista; Rabelo, Letícia Martins; Ferreira, Raíssa de Oliveira; E Silva, Bianca Costa; de Souza, Joyce Moreira; de Menezes, Ivandilson Pessoa Pinto; Rodrigues, Aline Sueli de Lima; Malafaia, Guilherme

    2016-10-01

    Tannery effluents constitute highly polluting residues, which can cause negative impacts to people's health and the environment. However, studies that have investigated the effects of the exposure to these xenobiotics on the central nervous system of mammal experimental models are rare, the few that have been published focusing on the exposure via oral intake (ingestion of water containing tannery effluent concentrations). In this sense, and with the objective of expanding the knowledge beyond the neurotoxic effects observed when water contaminated by these xenobiotics is ingested, the neurobehavioral effects of dermal exposure of male C57Bl/6J and Swiss mice were analyzed. The animals were exposed to raw (wet blue-type) tannery effluent for two hours during five days, totalizing 15 days of exposure. Afterwards, the animals underwent the elevated plus-maze (predictive of anxiety) and the object recognition tests (identification of memory deficit). Our data show that the dermal exposure to the tannery effluent caused an anxiogenic behavior in these animals, when compared those that did not have direct contact with these xenobiotics. It was also observed that the animals exposed to the tannery effluent obtained lower novel object recognition indices, thus evidencing memory deficit and indicating a possible influence of the tannery effluent constituents in animal cognition. The present study attests the hypothesis that dermal exposure to tannery effluents containing neurotoxic substances causes behavioral disorders in C57Bl/6J and Swiss mice. PMID:27380225

  5. Code validation and scaling of the LOBI BL-30 experiment

    International Nuclear Information System (INIS)

    Integral test facilities (ITFs) are one of the main tools for the validation of best-estimate thermalhydraulic system codes. The experimental data are also of great value when compared to the experiment scaled-conditions in a full Nuclear Power Plant (NPP). The LOBI-MOD2 was a single plus a triple loop (simulated by one loop) test facility electrically heated to simulate a 1300 MWe Pressurized Water Reactor (PWR). The scaling factor was 712 for the core power, volume and mass flow. Primary and secondary sides contained all the main active elements. It was located and operated at the European Commission Joint Research Centre (JRC) of Ispra, Italy. Experimental data of tests performed at the facility are available on-line through the JRC STRESA web platform for code validation purposes. The paper is focused in the simulation (with RELAP5 Mod-3.3) of the LOBI BL-30 experiment - a 5% small break Loss Of Coolant Accident (SB-LOCA) in the cold leg - the prediction of the general timing of events and primary system and secondary system quantities trends appear to be in good agreement with experimental data. The exercise continued with the simulation (with RELAP5 Mod 3.3) of the scaling of the LOBI BL-30 experiment to the Spanish reactor ASCO-2, a 3-loops 2940.6 MWth Westinghouse PWR. We have obtained good agreement with experimental data and have explained the reason of some discrepancies in the accumulator behaviour. To complete and compare the results, for the same NPP two other calculations have been performed: a non-scaled reference calculation of a 5% SB-LOCA in the cold leg with all the typical NPP safety systems connected and a SB-LOCA calculation with only the break area scaled and all the typical NPP safety systems connected. Both calculations have led to a safe end of the transient

  6. Defective insulin secretory response to intravenous glucose in C57Bl/6J compared to C57Bl/6N mice

    Directory of Open Access Journals (Sweden)

    Grace Fergusson

    2014-12-01

    Conclusions: The Bl/6J mouse strain displays impaired insulin secretion. These results have important implications for choosing the appropriate test to assess beta-cell function and background strain in genetically modified mouse models.

  7. Differential Localization of Pain-Related and Pain-Unrelated Neural Responses for Acupuncture at BL60 Using BOLD fMRI

    Directory of Open Access Journals (Sweden)

    Na-Hee Kim

    2013-01-01

    Full Text Available The objective of this study was to differentiate between pain-related and pain-unrelated neural responses of acupuncture at BL60 to investigate the specific effects of acupuncture. A total of 19 healthy volunteers were evaluated. fMRI was performed with sham or verum acupuncture stimulation at the left BL60 before and after local anesthesia. To investigate the relative BOLD signal effect for each session, a one-sample t-test was performed for individual contrast maps, and a paired t-test to investigate the differences between the pre- and post-anesthetic signal effects. Regarding verum acupuncture, areas that were more activated before local anesthesia included the superior, middle, and medial frontal gyri, inferior parietal lobule, superior temporal gyrus, thalamus, middle temporal gyrus, cingulate gyrus, culmen, and cerebellar tonsil. The postcentral gyrus was more deactivated before local anesthesia. After local anesthesia, the middle occipital gyrus, inferior temporal gyrus, postcentral gyrus, precuneus, superior parietal lobule, and declive were deactivated. Pre-anesthetic verum acupuncture at BL60 activated areas of vision and pain transmission. Post-anesthetic verum acupuncture deactivated brain areas of visual function, which is considered to be a pain-unrelated acupuncture response. It indicates that specific effects of acupoint BL60 are to control vision sense as used in the clinical setting.

  8. Dicty_cDB: FC-BL06 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available FC (Link to library) FC-BL06 (Link to dictyBase) - G03255 DDB0183956 Contig-U15205-1 FC-BL06E (L ... **reynlkanyrfsmeml*gt*estn*kfkfnhl*r*rdfiidsrcirgg*risk * ikes*ktiwsslfretsslkrwychsrwrinhr*s**r*ek**ckw*nl ...

  9. $Z^\\prime_{BL}$ portal dark matter and LHC Run-2 results

    CERN Document Server

    Okada, Nobuchika

    2016-01-01

    We consider a concise dark matter scenario in the minimal gauged $B-L$ extension of the Standard Model (SM), where the global $B-L$ (baryon number minus lepton number) symmetry in the SM is gauged, and three generations of right-handed neutrinos and a $B-L$ Higgs field are introduced. Associated with the $B-L$ gauge symmetry breaking by a VEV of the $B-L$ Higgs field, the seesaw mechanism for generating the neutrino mass is automatically implemented after the electroweak symmetry breaking in the SM. In this model context, we introduce a $Z_2$-parity and assign an odd parity for one right-handed neutrino while even parities for the other fields. Therefore, the dark matter candidate is identified as the right-handed Majorana neutrino with odd $Z_2$ parity, keeping the minimality of the particle content intact. When the dark matter particle communicates with the SM particles mainly through the $B-L$ gauge boson ($Z^\\prime_{BL}$ boson), its relic abundance is determined by only three free parameters, the $B-L$ ga...

  10. C57BL/6 mouse model of epithelial ovarian cancer and its biological characteristics%C57BL/6小鼠上皮性卵巢癌模型的建立及其生物学特性

    Institute of Scientific and Technical Information of China (English)

    张祖娟; 李艺; 崔恒; 昌晓红; 陈新华; 叶雪

    2012-01-01

    Objective To establish epithelial ovarian cancer of peritoneal metastasis model and subcutaneous tumor model in immunocompetent C57BL/6 mice, thus to provide basis of diagnosis, treatment and prevention- related basic research for ovarian cancer. Methods Cultured inbred C57BL/6 mice poorly differentiated ovarian ade-nocarcinoma cell line ID- 8 in vitro. SPF grade C57BL/6 female mice (6~8 weeks) were inoculated with logarithmic phase of ID- 8 cells with 1X 107, 5 X 106, 1X 106 and 1 X 105 cells / dose intraperitoneally and subcutaneously into the flank. They were invided into 8 groups with 6 in each. Tumor formation rate, ascites, metastasis and survival rate were recorded. An additional set of 6 animals were injected intraperitoneally (5 X106 ID - 8 cells) and then sacrificed at different time intervals for necropsy and pathologic analysis. The remaining animals were sacrificed and examined just before they died. Results The tumor formation rate was 100%. In peritoneal tumor model group, the average survival time was (141 + 6. 7) d, (122.8 + 4.5) d, (83.4 + 7.2) d, (74.4 + 4.5) d in 1X 105, 1X 106, 5 X 106 and 1 X 107 ID- 8 cells group, with the tumor cell load increased, the survival time was significantly shorter (P<0. 05). In subcutaneous tumor group, nodule formation time was about 1 week in 1 X 107 cells group; 1 week in 5X106 cells group; 3 weeks in IX 106 cells group and 6 weeks in 1X105 cells group. As the tumor cells inoculation load increased, the diameter and volume of tumor increased significantly (P<0. 05). Conclusions C57BL/6 mice intraperitoneal ovarian cancer model is similar to human epithelial ovarian cancer stage Ⅲ and Ⅳ. The immune or drug therapy efficacy is easier observed in subcutaneous tumor model. Establishing the ID- 8 cells ovarian cancer tumor model in immunocompetent C57BL/6 mice is helpful for clinical study of the treatment of ovarian cancer and immunological study of molecular models.%目的 在免疫功能正常的C57BL/6小

  11. MAGIC discovery and multiwavelength observations of the BL Lac 1ES 1727+502

    CERN Document Server

    Berger, K; Lindfors, E; Lombardi, S; Stamerra, A

    2013-01-01

    Blazars, active galactic nuclei whose jet axis is pointed towards the observer, constitute the most numerous class of extragalactic very high energy (VHE, E > 100\\, GeV) gamma-ray emitters. The MAGIC experiment, a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary Island of La Palma (Northern hemisphere), with an energy threshold of 50 GeV, is a well suited experiment for observations of such objects. Here we present the discovery of the BL Lac 1ES 1727+502 (z = 0.055) as VHE source. This object was identified as a promising TeV candidate based on archival data and the observation that lead to this detection was not triggered by any high state alert in other wavebands. The MAGIC observations are complemented by other observations are lower frequencies: optical data from the KVA telescope, UV, optical and X-ray archival data taken with the instruments on board the Swift satellite and high energy (HE, 300 MeV < E < 100 GeV) data from the \\textit{Fermi}-LAT instrument. We studied ...

  12. Comparison of the Effects of Maternal Supportive Care and Acupressure (at BL32 Acupoint) on Labor Length and Infant's Apgar Score

    OpenAIRE

    Akbarzadeh, Marzieh; Masoudi, Zahra; Zare, Najaf; Kasraeian, Maryam

    2015-01-01

    Background and Objectives: Prolonged labor leads to increase of cesarean deliveries, reduction of fetal heart rate, and maternal as well as infantile complications. Therefore, many women tend to use pharmacological or non-pharmacological methods for reduction of labor length. The present study aimed to compare the effects of maternal supportive care and acupressure (at BL32 acupoint) on labor length and infant's Apgar score. Methods: In this clinical trial, 150 women with low-risk pregnancy w...

  13. Engraftment of bone marrow-derived cells after nonlethal radiation in syngeneic C57BL/6mice%Engraftment of bone marrow-derived cells after nonlethal radiation in syngeneic C57BL/6 mice

    Institute of Scientific and Technical Information of China (English)

    Wu Liao; Tan Li; Wang Yu; Liu Dengqun; Shi Chunmeng

    2015-01-01

    Objective To study the characteristics of cell engraftment in mice at a lower dose under nonlethal radiated condition.Methods A syngeneic C57BL/6 mouse model,transplanted with 1 × 107 bone marrow cells and exposed to 2.5 Gy whole body irradiation (WBI),was selected to study the chimerism of cells from green fluorescent protein positive (GFP +) transgenic mice.The control group was injected with GFP + cells without receiving irradiation.In addition,an allogenic transplantation model of BALB/c mice was also investigated which was infused by GFP + cells from C57BL/6 mice.The engraftment of bone marrow-derived cells (BMDCs) was detected by immunohistochemistry in bone marrow,liver,lung,small intestine and spleen.Results The transplanted bone marrow cells successfully grafted in the haematopoietic tissues from syngeneic GFP transgenic mice.The transplanted GFP+ cells were also detected in the non-haematopoietic tissues,such as the small intestine,liver,spleen and lung,after irradiation.However,a lethal dose irradiation of 8 Gy was required to establish successful chimerism in allogeneic transplantation model by infusing the bone marrow cells from C57BL/6 mice to BALB/c mice.Conclusions Bone marrow-derived cells can be successfully grafted into various recipient tissues receiving a 2.5 Gy dose of radiation in syngeneic mice,but not in allogeneic mice.This nonlethal model may help to further study the plasticity and mechanism of bone marrow-derived cells in tissue repair and regeneration after radiation injury.

  14. Fluvastatin Influences Hair Color in C57Bl/6 Mice

    Directory of Open Access Journals (Sweden)

    Jarosław Jóźwiak

    2013-07-01

    Full Text Available Our recent in vitro experiments suggest that fluvastatin may influence tyrosinase (key enzyme of melanogenesis synthesis. The aim of the present study was to verify those findings in experiments, in vitro, in melanoma cell line, and in vivo, in mice. The expression of tyrosinase in B16F10 melanoma cell line, after induction of melanogenesis by UVB irradiation, was examined by Western blot analysis. Afterwards, the effect of fluvastatin on melanin synthesis in hair follicles of C57Bl/6 mice was investigated. The expression of tyrosinase was reduced in the presence of fluvastatin. In mice after anagen induction over the dorsal skin, gel containing fluvastatin in various concentrations was injected subcutaneously, while in part of control groups of mice, gel with placebo was injected. In addition, gel with fluvastatin was injected to four week-old mice (mice in first postnatal anagen without anagen induction. In extension, injections of gel with fluvastatin or placebo were performed in mice without anagen induction (but after first postnatal anagen. In part of study group of mice (mice after anagen induction and injection of fluvastatin regrowth of depigmented hair was observed, while in all control groups (mice after injection of placebo, such hair depigmentation over the skin area was not found. In conclusion, this study, for the first time, shows that fluvastatin might affect melanin synthesis in vivo.

  15. Observational learning in C57BL/6j mice.

    Science.gov (United States)

    Carlier, Pascal; Jamon, Marc

    2006-11-01

    The ability of mice to solve a complex task by observational learning was investigated with C57BL/6j mice. Four female demonstrators were trained to reliably perform a sequence that consisted in pushing a piece of food into a tube attached to the side of a puzzle box, and recovering it by opening a drawer in front of the box. They then performed this sequence in front of naive mice assigned to individual cubicles in a box with a wire mesh front arranged in a row facing the demonstrators. A total of 25 naive mice (13 males and 12 females) were used. Fifteen mice observed 14 demonstrations a day for 5 days; 10 control mice were placed in similar cubicles, but behind a plastic screen which prevented them from observing the demonstrators. The mice were post-tested in the demonstrator situation, and 6 of 15 observers immediately reproduced the complete task successfully, but none of the naive or control mice were able to solve the task. The observers and controls were then subjected to a five level individual learning schedule. Observers learned the individual task significantly faster than the controls. No sex difference was found. These results suggest that observational learning processes at work were based on stimulus enhancement and observational conditioning. PMID:16939695

  16. Complex Scalar DM in a B-L Model

    CERN Document Server

    Sánchez-Vega, B L; Schmitz, E R

    2014-01-01

    In this work, we implement a complex scalar Dark Matter (DM) candidate in a $U(1)_{B-L}$ gauge extension of the Standard Model. The model contains three right handed neutrinos with different quantum numbers and a rich scalar sector, with extra doublets and singlets. In principle, these extra scalars can have VEVs ($V_{\\Phi}$ and $V_{\\phi}$ for the extra doublets and singlets, respectively) belonging to different energy scales. In the context of $\\zeta\\equiv\\frac{V_{\\Phi}}{V_{\\phi}}\\ll1$, which allows to obtain naturally light active neutrino masses and mixing compatible with neutrino experiments, the DM candidate arises by imposing a $Z_{2}$ symmetry on a given complex singlet, $\\phi_{2}$, in order to make it stable. After doing a study of the scalar potential and the gauge sector, we obtain all the DM dominant processes concerning the relic abundance and direct detection. Then, for a representative set of parameters, we found that a complex DM with mass around $200$ GeV, for example, is compatible with the c...

  17. Antiparasitic activities of acridone alkaloids from Swinglea glutinosa (Bl.) Merr

    International Nuclear Information System (INIS)

    Eleven acridone alkaloids isolated from Swinglea glutinosa (Bl.) Merr. were examined for in vitro activity against chloroquine-sensitive Plasmodium falciparum 3D7, Trypanosoma brucei rhodesiense STIB900 and Leishmania donovani L82. An assay with KB cells was developed in order to compare in vitro toxicity of alkaloids with the selective action on the parasites. Nine of the compounds had IC50 values ranging from 0.3 to 11.6 μM against P. falciparum. In contrast, a small number of compounds showed significant activity against T. brucei rhodesiense and none had activity against L. donovani. Among the alkaloids three had IC50 50 < 10 μM. The characterization of the acridone alkaloids, 1,3,5-trihydroxy-4-methoxy-10-methyl-2,8-bis(3-methylbut-2-enyl)acridin-9 (10H)-one (1), 2,3-dihydro-4,9-dihydroxy-2-(2-hydroxypropan-2-yl)-11-methoxy-10-methylfuro [3,2-b] acridin-5(10H)-one (2) and 3,4-dihydro-3,5,8-trihydroxy-6-methoxy-2,2,7-trimethyl-2Hpyrano[ 2,3-a]acridin-12(7H)-one (3), is discussed, as well as the structure-activity relationship of all compounds assayed. Isolation and spectral data of alkaloids 1-3 are described for the first time although their cytotoxicities to cancer cells have been described before. (author)

  18. Electroweak vacuum stability in classically conformal $B-L$ extension of the Standard Model

    CERN Document Server

    Das, Arindam; Papapietro, Nathan

    2015-01-01

    We consider the minimal U(1)$_{B-L}$ extension of the Standard Model (SM) with the classically conformal invariance, where an anomaly free U(1)$_{B-L}$ gauge symmetry is introduced along with three generations of right-handed neutrinos and a U(1)$_{B-L}$ Higgs field. Because of the classically conformal symmetry, all dimensional parameters are forbidden. The $B-L$ gauge symmetry is radiatively broken through the Coleman-Weinberg mechanism, generating the mass for the $U(1)_{B-L}$ gauge boson ($Z^\\prime$ boson) and the right-handed neutrinos. Through a small negative coupling between the SM Higgs doublet and the $B-L$ Higgs field, the negative mass term for the SM Higgs doublet is generated and the electroweak symmetry is broken. In this model context, we investigate the electroweak vacuum instability problem in the SM. It is known that in the classically conformal U(1)$_{B-L}$ extension of the SM, the electroweak vacuum remains unstable in the renormalization group analysis at the one-loop level. In this pape...

  19. Gauge $B-L$ Model of Radiative Neutrino Mass with Multipartite Dark Matter

    OpenAIRE

    Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza

    2016-01-01

    We propose an extension of the standard model of quarks and leptons to include gauge $B-L$ symmetry with an exotic array of neutral fermion singlets for anomaly cancellation. With the addition of suitable scalars also transforming under $U(1)_{B-L}$, this becomes a model of radiative seesaw neutrino mass with possible multipartite dark matter. If leptoquark fermions are added, necessarily also transforming under $B-L$, the diphoton excess at 750 GeV, recently observed at the Large Hadron Coll...

  20. Right-handed neutrino dark matter under the B-L gauge interaction

    OpenAIRE

    Kaneta, Kunio; Kang, Zhaofeng; Lee, Hye-Sung

    2016-01-01

    We study the right-handed neutrino (RHN) dark matter candidate in the minimal U(1)_{B-L} gauge extension of the standard model. The U(1)_{B-L} gauge symmetry offers three RHNs which can address the origin of the neutrino mass, the relic dark matter, and the matter-antimatter asymmetry of the universe. The lightest among the three can be a sufficiently long-lived dark matter candidate, without an additional stability mechanism, which is under the B-L gauge interaction. We investigate various s...

  1. Gauge $B-L$ Model of Radiative Neutrino Mass with Multipartite Dark Matter

    CERN Document Server

    Ma, Ernest; Popov, Oleg; Zakeri, Mohammadreza

    2016-01-01

    We propose an extension of the standard model of quarks and leptons to include gauge $B-L$ symmetry with an exotic array of neutral fermion singlets for anomaly cancellation. With the addition of suitable scalars also transforming under $U(1)_{B-L}$, this becomes a model of radiative seesaw neutrino mass with possible multipartite dark matter. If leptoquark fermions are added, necessarily also transforming under $B-L$, the diphoton excess at 750 GeV, recently observed at the Large Hadron Collider, may also be explained.

  2. C57BL/6N mutation in Cytoplasmic FMR interacting protein 2 regulates cocaine response

    OpenAIRE

    Kumar, Vivek; Kim, Kyungin; Joseph, Chryshanthi; Kourrich, Saïd; Yoo, Seung Hee; Huang, Hung Chung; Vitaterna, Martha H.; de Villena, Fernando Pardo-Manuel; Churchill, Gary; Bonci, Antonello; Takahashi, Joseph S.

    2013-01-01

    The inbred mouse C57BL/6J is the reference strain for genome sequence and for most behavioral and physiological phenotypes. However the International Knockout Mouse Consortium uses an embryonic stem cell line derived from a related C57BL/6N substrain. We found that C57BL/6N has lower acute and sensitized response to cocaine and methamphetamine. We mapped a single causative locus and identified a non-synonymous mutation of serine to phenylalanine (S968F) in Cytoplasmic FMR interacting protein ...

  3. A new B-L model without right-handed neutrinos

    OpenAIRE

    Patra, Sudhanwa; Rodejohann, Werner; Yaguna, Carlos E.

    2016-01-01

    We propose and study a novel extension of the Standard Model based on the B-L gauge symmetry that can account for dark matter and neutrino masses. In this model, right-handed neutrinos are absent and the gauge anomalies are canceled instead by four chiral fermions with fractional B-L charges. After the breaking of $U(1)_{B-L}$, these fermions arrange themselves into two Dirac particles, the lightest of which is automatically stable and plays the role of the dark matter. We determine the regio...

  4. The BL-Lac gamma-ray blazar PKS 1424+240 associated with a group of galaxies at z=0.6010

    CERN Document Server

    Rovero, A C; Donzelli, C; Pichel, A

    2016-01-01

    PKS 1424+240 is a BL-Lac blazar with unknown redshift that was detected at high-energy gamma rays by Fermi-LAT with a hard spectrum. At VHE, it was first detected by VERITAS and later confirmed by MAGIC. Its spectral energy distribution is highly attenuated at VHE gamma rays, which is coherent with distant sources. Several estimations enabled the redshift to be constrained to the range 0.6 < z < 1.3. These results place PKS 1424+240 in the very interesting condition of being probably the most distant blazar that has been detected at VHE. The ambiguity in the redshift is still large enough to prevent precise studies of the EBL and the intrinsic blazar spectrum. Given the difficulty of measuring spectroscopic redshifts for BL-Lac objects directly, we aim to establish a reliable redshift value for this blazar by finding its host group of galaxies. Elliptical galaxies are associated with groups, and BL-Lac objects are typically hosted by them, so we decided to search for the host group of the blazar. For th...

  5. Antiparasitic activities of acridone alkaloids from Swinglea glutinosa (Bl.) Merr

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Djalma A.P. dos; Vieira, Paulo C.; Silva, M. Fatima das G.F. da; Fernandes, Joao B. [Universidade Federal de Sao Carlos, SP (Brazil). Dept. de Quimica; Rattray, Lauren; Croft, Simon L. [London School of Hygiene and Tropical Medicine, London (United Kingdom). Dept. of Infectious and Tropical Diseases

    2009-07-01

    Eleven acridone alkaloids isolated from Swinglea glutinosa (Bl.) Merr. were examined for in vitro activity against chloroquine-sensitive Plasmodium falciparum 3D7, Trypanosoma brucei rhodesiense STIB900 and Leishmania donovani L82. An assay with KB cells was developed in order to compare in vitro toxicity of alkaloids with the selective action on the parasites. Nine of the compounds had IC{sub 50} values ranging from 0.3 to 11.6 {mu}M against P. falciparum. In contrast, a small number of compounds showed significant activity against T. brucei rhodesiense and none had activity against L. donovani. Among the alkaloids three had IC{sub 50} < 1.0 {mu}M against P. falciparum, whereas against T. b. rhodesiense five had IC{sub 50} < 10 {mu}M. The characterization of the acridone alkaloids, 1,3,5-trihydroxy-4-methoxy-10-methyl-2,8-bis(3-methylbut-2-enyl)acridin-9 (10H)-one (1), 2,3-dihydro-4,9-dihydroxy-2-(2-hydroxypropan-2-yl)-11-methoxy-10-methylfuro [3,2-b] acridin-5(10H)-one (2) and 3,4-dihydro-3,5,8-trihydroxy-6-methoxy-2,2,7-trimethyl-2Hpyrano[ 2,3-a]acridin-12(7H)-one (3), is discussed, as well as the structure-activity relationship of all compounds assayed. Isolation and spectral data of alkaloids 1-3 are described for the first time although their cytotoxicities to cancer cells have been described before. (author)

  6. Neural stem cell isolation and culture from C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    S Koirala

    2015-07-01

    Full Text Available INTRODUCTION A widely used in vitro culture, the neurosphere assay (NSA has provided a means to retrospectively identify neural progenitor cells as well as to determine both their selfrenewal capacity. Objective of study was to isolate and compare growth of the embryonic neuronal stem cell and adult neuronal stem cells in presence of Epidermal Growth Factor (EGF and Fibroblastic Growth Factor (FGF2. MATERIALS AND METHODS Embryonic neuronal stem cell were collected from cortical plate of dorsal telencephalon of fifteen C57BL/6 transgenic mice using stereoscopic microscope on 11th gestational day (GD. Adult mammalian neuronal stem cells taken from subventricular zone (SVZ of the lateral ventricles and subgranular layer of the dentate gyrus of the hippocampus were cultured. The growth for the neurosphere was then observed in interval of 24 and 72 hours. RESULT The adult stem cell culture showed few intact cells with high amount of debris and 9% heterogeneous sphere after 24 hours while only 20 % was observed at the end of 72 hours. Higher proliferation rate was observed in embryonic neurospheres than the adult stem cell culture. CONCLUSION Presence of EGF and basic FGF2 is essential for culture of neurospheres.DOI: http://dx.doi.org/10.3126/jcmsn.v10i2.12946 Journal of College of Medical Sciences-Nepal, 2014, Vol.10(2; 1-3

  7. Discovery of VHE gamma-rays from the distant BL Lac 1ES 0347-121

    CERN Document Server

    Aharonian, F; Barres de Almeida, U; Bazer-Bachi, A R; Behera, B; Beilicke, M; Benbow, W; Bernlöhr, K; Boisson, C; Bolz, O; Borrel, V; Braun, I; Brion, E; Brown, A M; Buhler, R; Bulik, T; Büsching, I; Boutelier, T; Carrigan, S; Chadwick, P M; Chounet, L M; Clapson, A C; Coignet, G; Cornils, R; Costamante, L; Dalton, M; Degrange, B; Dickinson, H J; Djannati-Ata:, A; Domainko, W; O'Connor-Drury, L; Dubois, F; Dubus, G; Dyks, J; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Feinstein, F; Fiasson, A; Förster, A; Fontaine, G; Funk, Seb; Fuling, M; Gallant, Y A; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Hadjichristidis, C; Hauser, D; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Holleran, M; Hoppe, S; Horns, D; Jacholkowska, A; De Jager, O C; Jung, I; Katarzynski, K; Kendziorra, E; Kerschhaggl, M; Khelifi, B; Keogh, D; Komin, Nu; Kosack, K; Lamanna, G; Latham, I J; Lemiere, A; Lemoine-Goumard, M; Lenain, J P; Lohse, T; Martin, J M; Martineau-Huynh, O; Marcowith, A; Masterson, C; Maurin, D; Maurin, G; McComb, T J L; Moderski, R; Moulin, E; De Naurois, Mathieu; Nedbal, D; Nolan, S J; Ohm, S; Olive, J P; De Ona Wilhelmi, E; Orford, K J; Osborne, J L; Ostrowski, M; Panter, M; Pedaletti, G; Pelletier, G; Petrucci, P O; Pita, S; Pühlhofer, G; Punch, M; Ranchon, S; Raubenheimer, B C; Raue, M; Rayner, S M; Renaud, M; Ripken, J; Rob, L; Rolland, L; Rosier-Lees, S; Rowell, G; Rudak, B; Ruppel, J; Sahakian, V V; Santangelo, A; Schlickeiser, R; Schock, F; Schroder, R; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Sol, H; Spangler, D; Stawarz,; Steenkamp, R; Stegmann, C; Superina, G; Tam, P H; Tavernet, J P; Terrier, R; Van Eldik, C; Vasileiadis, G; Venter, C; Vialle, J P; Vincent, P; Vivier, M; Völk, H J; Volpe, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A

    2007-01-01

    Aims: Our aim is to study the production mechanism for very-high-energy (VHE; >100GeV) gamma-rays in distant active galactic nuclei (AGN) and use the observed VHE spectrum to derive limits on the Extragalactic Background Light (EBL). We also want to determine physical quantities through the modeling of the object's broad-band spectral energy distribution (SED). Methods: VHE observations (~25h live time) of the BL Lac 1ES 0347-121 (redshift z=0.188) were conducted with the High Energy Stereoscopic System (H.E.S.S.) between August and December 2006. Contemporaneous X-ray and UV/optical observations from the SWIFT satellite are used to interpret the SED of the source in terms of a synchrotron self Compton (SSC) model. Results: An excess of 327 events, corresponding to a statistical significance of 10.1 standard deviations, is detected from 1ES 0347-121. Its photon spectrum, ranging from ~250GeV to ~3TeV, is well described by a power law with a photon index of Gamma = 3.10 +/- 0.23_stat +/- 0.10_sys. The integral...

  8. 243 244Cm studies in C57BL/Do mice

    International Nuclear Information System (INIS)

    Three groups of C57BL/Do mice were injected with different activities of 243244Cm so that the long-term biological effects could be evaluated. Effective skeletal retention equations were used to calculate the cumulative mean skeletal dose in rad at 140 days before death in each group of mice. The primary objective of this study was to determine the relative biological effectiveness (RBE) of 243244Cm compared to 226Ra, using bone sarcoma induction at the end point. Combined data for male and female mice permitted the RBE value +/- SD for 243244Cm to be calculated as 4.4 +/- 1.8 compared to 1.0 for 226Ra. A comparison of RBE values from a previous study in this mouse strain and the value for 243244Cm from this study suggest that the trivalent actinides 241Am, /sup 243,244/Cm, and 249Cf are about three times less effective for bone sarcoma induction than 239Pu

  9. Differential Mammary Gland Development in FVB and C57Bl/6 Mice: Implications for Breast Cancer Research

    Directory of Open Access Journals (Sweden)

    Breanne M. Anderson

    2011-10-01

    Full Text Available A growing body of research suggests a linkage between pubertal mammary gland development and environmental factors such as diet as modifiers of long term breast cancer risk. Much of this research is dependent upon mouse models, which may vary between studies. However, effects may be strain dependent and further modified by diet, which has not been previously examined. Therefore, the objective of the present study was to determine whether mammary gland development differs between FVB and C57Bl/6 strains on diets containing either n-6 or n-3 polyunsaturated fats. Developmental measures related to onset of puberty and mammary gland development differed between strains. Mice fed the n-3 polyunsaturated fatty acids (PUFA diet were shown to have lower numbers of terminal end buds, a marker of mammary gland development. This study helps to further clarify differences in development and dietary response between FVB and C57Bl/6 mice in order to more appropriately relate mammary gland research to human populations.

  10. Erionite induces production of autoantibodies and IL-17 in C57BL/6 mice

    International Nuclear Information System (INIS)

    Background: Erionite has similar chemical and physical properties to amphibole asbestos, which induces autoantibodies in mice. Current exposures are occurring in North Dakota due to the use of erionite-contaminated gravel. While erionite is known to cause mesothelioma and other diseases associated with asbestos, there is little known about its effects on the immune system. Objectives: We performed this study to determine whether erionite evokes autoimmune reactions in mice. Methods: Bone marrow derived macrophages (BMDM) were used to measure toxicity induced by erionite. Cytokine production by BMDM and splenocytes of C57BL/6 mice was examined by bead arrays and ELISA following exposure to erionite, amphiboles and chrysotile. Wild type C57BL/6 mice were exposed to saline, erionite, amphibole asbestos (Libby 6-Mix) or chrysotile through intratracheal instillations at equal mass (60 μg/mouse). Seven months after exposure, sera were examined for anti-nuclear antibodies (ANA) and IL-17. Immunohistochemistry was used to detect immune complex deposition in the kidneys. Results: Erionite and tremolite caused increased cytokine production belonging to the TH17 profile including IL-17, IL-6, TGF-β, and TNF-α. The frequency of ANA was increased in mice treated with erionite or amphibole compared to saline-treated mice. IL-17 and TNF-α were elevated in the sera of mice treated with erionite. The frequency of immune complex deposition in the kidneys increased from 33% in saline-treated mice to 90% with erionite. Conclusions: These data demonstrate that both erionite and amphibole asbestos induce autoimmune responses in mice, suggesting a potential for adverse effects in exposed communities. - Highlights: • Erionite, a fibrous mineral, is a current public health concern in the western USA. • Erionite exposure induces antinuclear autoantibodies in exposed mice. • Erionite induces a clear Th17 cytokine response in vitro and in vivo. • These responses were distinct from

  11. Erionite induces production of autoantibodies and IL-17 in C57BL/6 mice

    Energy Technology Data Exchange (ETDEWEB)

    Zebedeo, Christian Nash; Davis, Chad [Department of Biological Sciences, Idaho State University, Pocatello, ID (United States); Peña, Cecelia [Northwest Nazarene University, Nampa, ID (United States); Ng, Kok Wei [Department of Biological Sciences, Idaho State University, Pocatello, ID (United States); Pfau, Jean C., E-mail: pfaujean@isu.edu [Department of Biological Sciences, Idaho State University, Pocatello, ID (United States)

    2014-03-15

    Background: Erionite has similar chemical and physical properties to amphibole asbestos, which induces autoantibodies in mice. Current exposures are occurring in North Dakota due to the use of erionite-contaminated gravel. While erionite is known to cause mesothelioma and other diseases associated with asbestos, there is little known about its effects on the immune system. Objectives: We performed this study to determine whether erionite evokes autoimmune reactions in mice. Methods: Bone marrow derived macrophages (BMDM) were used to measure toxicity induced by erionite. Cytokine production by BMDM and splenocytes of C57BL/6 mice was examined by bead arrays and ELISA following exposure to erionite, amphiboles and chrysotile. Wild type C57BL/6 mice were exposed to saline, erionite, amphibole asbestos (Libby 6-Mix) or chrysotile through intratracheal instillations at equal mass (60 μg/mouse). Seven months after exposure, sera were examined for anti-nuclear antibodies (ANA) and IL-17. Immunohistochemistry was used to detect immune complex deposition in the kidneys. Results: Erionite and tremolite caused increased cytokine production belonging to the T{sub H}17 profile including IL-17, IL-6, TGF-β, and TNF-α. The frequency of ANA was increased in mice treated with erionite or amphibole compared to saline-treated mice. IL-17 and TNF-α were elevated in the sera of mice treated with erionite. The frequency of immune complex deposition in the kidneys increased from 33% in saline-treated mice to 90% with erionite. Conclusions: These data demonstrate that both erionite and amphibole asbestos induce autoimmune responses in mice, suggesting a potential for adverse effects in exposed communities. - Highlights: • Erionite, a fibrous mineral, is a current public health concern in the western USA. • Erionite exposure induces antinuclear autoantibodies in exposed mice. • Erionite induces a clear Th17 cytokine response in vitro and in vivo. • These responses were

  12. EVN Observations of HESS J1943+213: Evidence for an Extreme TeV BL Lac Object

    OpenAIRE

    Akiyama, Kazunori; Stawarz, Łukasz; Tanaka, Yasuyuki T.; Nagai, Hiroshi; Giroletti, Marcello; Honma, Mareki

    2016-01-01

    We report on the 1.6 GHz (18 cm) VLBI observations of the unresolved, steady TeV source HESS J1943+213 located in the Galactic plane, performed with the European VLBI Network (EVN) in 2014. Our new observations with a nearly full EVN array provide the deepest image of HESS J1943+213 at the highest resolution ever achieved, enabling us to resolve the long-standing issues of the source identification. The milliarcsecond-scale structure of HESS J1943+213 has a clear asymmetric morphology, consis...

  13. VizieR Online Data Catalog: VRI LCs of BL Lac object Mrk 501 from 2010 to 2015 (Xiong+, 2016)

    Science.gov (United States)

    Xiong, D.; Zhang, H.; Zhang, X.; Yi, T.; Bai, J.; Wang, F.; Liu, H.; Zhen, Y.

    2016-03-01

    Our optical monitoring program of Mrk 501 was carried out with the 1.02m optical telescope located at the the Yunnan Astronomical Observatory of China. Our monitoring program for Mrk 501 was divided into five periods. The first period was from 2010 April 1-3, the second was from 2012 April 22-25, the third was from 2013 April 1-4, the fourth was from 2014 April 17-May 8, and the fifth was from 2015 April 6-May 25. Excluding the nights with bad weather and those devoted to other targets, the actual number of observations for Mrk 501 is 29 nights. The standard Johnson broadband filters were used. The typical integration times were 150-300s for the I and R filters and 400s for the V filter. (3 data files).

  14. Learning Vector Quantization for Classifying Astronomical Objects

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The sizes of astronomical surveys in different wavebands are increas-ing rapidly. Therefore, automatic classification of objects is becoming ever moreimportant. We explore the performance of learning vector quantization (LVQ) inclassifying multi-wavelength data. Our analysis concentrates on separating activesources from non-active ones. Different classes of X-ray emitters populate distinctregions of a multidimensional parameter space. In order to explore the distributionof various objects in a multidimensional parameter space, we positionally cross-correlate the data of quasars, BL Lacs, active galaxies, stars and normal galaxiesin the optical, X-ray and infrared bands. We then apply LVQ to classify them withthe obtained data. Our results show that LVQ is an effective method for separatingAGNs from stars and normal galaxies with multi-wavelength data.

  15. PATHOGENESIS OF METHANOL-INDUCED CRANIOFACIAL DEFECTS IN C57BL/6J MICE

    Science.gov (United States)

    BACKGROUND: Methanol administered to C57BL/6J mice during gastrulation causes severe craniofacial dysmorphology. We describe dysmorphogenesis, cell death, cell cycle assessment, and effects on development of cranial ganglia and nerves observed following administration of methanol...

  16. Radiative Symmetry Breaking in Supersymmetric $B-L$ Models with Inverse Seesaw

    CERN Document Server

    Khalil, Shaaban

    2016-01-01

    We study the radiative symmetry breaking of B-L in supersymmetric models with inverse seesaw mechanism. We show that for a wide region of parameter space the radiative corrections can drive the squared mass of the extra Higgs boson from positive initial values at the GUT scale to negative values at the TeV scale, leading to the spontaneous breaking of the B-L symmetry. We also emphasize that in this class of models, unlike the supersymmetric B-L models with type I seesaw, the right-handed sneutrino cannot get a non-zero vacuum expectation value. Therefore, B-L can be radiatively broken while R-parity remains an exact symmetry.

  17. Dark Matter and Neutrino Masses from Global $U(1)_{B-L}$ Symmetry Breaking

    CERN Document Server

    Lindner, Manfred; Schwetz, Thomas

    2011-01-01

    We present a scenario were neutrino masses and Dark Matter are related due to a global $U(1)_{B-L}$ symmetry. Specifically we consider neutrino mass generation via the Zee{Babu two-loop mecha- nism, augmented by a scalar singlet whose VEV breaks the global $U(1)_{B-L}$ symmetry. In order to obtain a Dark Matter candidate we introduce two Standard Model singlet fermions. They form a pseudo-Dirac particle and are stable because of a remnant $Z_2$ symmetry. Hence, in this model the stability of Dark Matter follows from the global $U(1)_{B-L}$ symmetry. We discuss the Dark Matter phenomenology of the model, and compare it to similar models based on gauged $U(1)_{B-L}$. We argue that in contrast to the gauged versions, the model based on the global symmetry does not suffer from sever constraints from Z' searches.

  18. A discussion of Bl conservation on a two dimensional magnetic field plane in watt balances

    Science.gov (United States)

    Li, Shisong; Zhao, Wei; Huang, Songling

    2016-05-01

    The watt balance is an experiment being pursued in national metrology institutes for precision determination of the Planck constant h. In watt balances, the 1/r magnetic field, expected to generate a geometrical factor Bl independent to any coil horizontal displacement, can be created by a strict two dimensional, symmetric (horizontal r and vertical z) construction of the magnet system. In this paper, we present an analytical understanding of magnetic field distribution when the r symmetry of the magnet is broken and the establishment of the Bl conservation is shown. By using either Gauss’s law on magnetism with monopoles or conformal transformations, we extend the Bl conservation to arbitrary two dimensional magnetic planes where the vertical magnetic field component equals zero. The generalized Bl conservation allows a relaxed physical alignment criteria for watt balance magnet systems.

  19. Molecular analysis of emerging radiation leukemia virus variants of C57BL/Ka mice

    International Nuclear Information System (INIS)

    Molecular cloning of several primary or passaged RadLV variants and their biological characterization has allowed the authors to propose a model of their emergence following X-ray irradiation of C57BL/6 mice. (author)

  20. A discussion of $Bl$ conservation on a two dimensional magnetic field plane in watt balances

    CERN Document Server

    Li, Shisong; Huang, Songling

    2015-01-01

    The watt balance is an experiment being pursued in national metrology institutes for precision determination of the Planck constant $h$. In watt balances, the $1/r$ magnetic field, expected to generate a geometrical factor $Bl$ independent to any coil horizontal displacement, can be created by a strict two dimensional, symmetric (horizontal $r$ and vertical $z$) construction of the magnet system. In this paper, we present an analytical understanding of magnetic field distribution when the $r$ symmetry of the magnet is broken and the establishment of the $Bl$ conservation is shown. By using either Gauss's law on magnetism with monopoles or conformal transformations, we extend the $Bl$ conservation to arbitrary two dimensional magnetic planes where the vertical magnetic field component equals zero. The generalized $Bl$ conservation allows a relaxed physical alignment criteria for watt balance magnet systems.

  1. Multi-walled carbon nanotube instillation impairs pulmonary function in C57BL/6 mice

    OpenAIRE

    Walters Dianne M; Rao Apparao M; Ke Pu Chun; Chen Pengyu; Podila Ramakrishna; Katwa Pranita; Wang Xiaojia; Wingard Christopher J; Brown Jared M

    2011-01-01

    Abstract Background Multi-walled carbon nanotubes (MWCNTs) are widely used in many disciplines due to their unique physical and chemical properties. Therefore, some concerns about the possible human health and environmental impacts of manufactured MWCNTs are rising. We hypothesized that instillation of MWCNTs impairs pulmonary function in C57BL/6 mice due to development of lung inflammation and fibrosis. Methods MWCNTs were administered to C57BL/6 mice by oropharyngeal aspiration (1, 2, and 4...

  2. Metabolic Deficiences Revealed in the Biotechnologically Important Model Bacterium Escherichia coli BL21(DE3)

    OpenAIRE

    Constanze Pinske; Markus Bönn; Sara Krüger; Ute Lindenstrauss; R Gary Sawers

    2011-01-01

    The Escherichia coli B strain BL21(DE3) has had a profound impact on biotechnology through its use in the production of recombinant proteins. Little is understood, however, regarding the physiology of this important E. coli strain. We show here that BL21(DE3) totally lacks activity of the four [NiFe]-hydrogenases, the three molybdenum- and selenium-containing formate dehydrogenases and molybdenum-dependent nitrate reductase. Nevertheless, all of the structural genes necessary for the synthesi...

  3. Structural basis for arabinoxylo-oligosaccharide capture by the probiotic Bifidobacterium animalis subsp lactis Bl-04

    OpenAIRE

    Ejby, Morten; Fredslund, Folmer; Vujicic-Zagar, Andreja; Svensson, Birte; Slotboom, Dirk Jan; Abou Hachem, Maher

    2013-01-01

    Glycan utilization plays a key role in modulating the composition of the gut microbiota, but molecular insight into oligosaccharide uptake by this microbial community is lacking. Arabinoxylo-oligosaccharides (AXOS) are abundant in the diet, and are selectively fermented by probiotic bifidobacteria in the colon. Here we show how selectivity for AXOS uptake is established by the probiotic strain Bifidobacterium animalis subsp. lactisBl-04. The binding protein BlAXBP, which is associated with an...

  4. Environmental Enrichment Reduces the Likelihood of Alopecia in Adult C57BL/6J Mice

    OpenAIRE

    Bechard, Allison; Meagher, Rebecca; Mason, Georgia

    2011-01-01

    Barbering (incessant grooming) is an abnormal behavior causing alopecia and commonly affects various strains of laboratory mice, including C57BL/6J. Barbering-induced alopecia is a potential symptom of brain impairment and can indicate a stressful environment. We compared alopecia prevalence and severity in mice housed in enriched or standard cages. Providing an enriched environment delayed the onset and reduced the prevalence and overall severity of alopecia in C57BL/6J mice. Husbandry metho...

  5. Sound objects – Auditory objects – Musical objects

    DEFF Research Database (Denmark)

    Hjortkjær, Jens

    2016-01-01

    The auditory system transforms patterns of sound energy into perceptual objects but the precise definition of an ‘auditory object’ is much debated. In the context of music listening, Pierre Schaeffer argued that ‘sound objects’ are the fundamental perceptual units in ‘musical objects’. In this...... paper, I review recent neurocognitive research suggesting that the auditory system is sensitive to structural information about real-world objects. Instead of focusing solely on perceptual sound features as determinants of auditory objects, I propose that real-world object properties are inherent in the...

  6. Sound objects – Auditory objects – Musical objects

    DEFF Research Database (Denmark)

    Hjortkjær, Jens

    2015-01-01

    The auditory system transforms patterns of sound energy into perceptual objects but the precise definition of an ‘auditory object’ is much debated. In the context of music listening, Pierre Schaeffer argued that ‘sound objects’ are the fundamental perceptual units in ‘musical objects’. In this...... paper, I review recent neurocognitive research suggesting that the auditory system is sensitive to structural information about real-world objects. Instead of focusing solely on perceptual sound features as determinants of auditory objects, I propose that real-world object properties are inherent in the...

  7. Quasi-objects, Cult Objects and Fashion Objects

    DEFF Research Database (Denmark)

    Andersen, Bjørn Schiermer

    2011-01-01

    This article attempts to rehabilitate the concept of fetishism and to contribute to the debate on the social role of objects as well as to fashion theory. Extrapolating from Michel Serres’ theory of the quasi-objects, I distinguish two phenomenologies possessing almost opposite characteristics. T...

  8. Learning Object Repositories

    Science.gov (United States)

    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.)

  9. The B-L phase transition. Implications for cosmology and neutrinos

    International Nuclear Information System (INIS)

    We investigate the possibility that the hot thermal phase of the early universe is ignited in consequence of the B-L phase transition, which represents the cosmological realization of the spontaneous breaking of the Abelian gauge symmetry associated with B-L, the difference between baryon number B and lepton number L. Prior to the B-L phase transition, the universe experiences a stage of hybrid inflation. Towards the end of inflation, the false vacuum of unbroken B-L symmetry decays, which entails tachyonic preheating as well as the production of cosmic strings. Observational constraints on this scenario require the B-L phase transition to take place at the scale of grand unification. The dynamics of the B-L breaking Higgs field and the B-L gauge degrees of freedom, in combination with thermal processes, generate an abundance of heavy (s)neutrinos. These (s)neutrinos decay into radiation, thereby reheating the universe, generating the baryon asymmetry of the universe and setting the stage for the thermal production of gravitinos. The B-L phase transition along with the (s)neutrino-driven reheating process hence represents an intriguing and testable mechanism to generate the initial conditions of the hot early universe. We study the B-L phase transition in the full supersymmetric Abelian Higgs model, for which we derive and discuss the Lagrangian in arbitrary and unitary gauge. As for the subsequent reheating process, we formulate the complete set of Boltzmann equations, the solutions of which enable us to give a detailed and time-resolved description of the evolution of all particle abundances during reheating. Assuming the gravitino to be the lightest superparticle (LSP), the requirement of consistency between hybrid inflation, leptogenesis and gravitino dark matter implies relations between neutrino parameters and superparticle masses, in particular a lower bound on the gravitino mass of 10GeV. As an alternative to gravitino dark matter, we consider the case of

  10. The B-L phase transition. Implications for cosmology and neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Kai

    2012-07-15

    We investigate the possibility that the hot thermal phase of the early universe is ignited in consequence of the B-L phase transition, which represents the cosmological realization of the spontaneous breaking of the Abelian gauge symmetry associated with B-L, the difference between baryon number B and lepton number L. Prior to the B-L phase transition, the universe experiences a stage of hybrid inflation. Towards the end of inflation, the false vacuum of unbroken B-L symmetry decays, which entails tachyonic preheating as well as the production of cosmic strings. Observational constraints on this scenario require the B-L phase transition to take place at the scale of grand unification. The dynamics of the B-L breaking Higgs field and the B-L gauge degrees of freedom, in combination with thermal processes, generate an abundance of heavy (s)neutrinos. These (s)neutrinos decay into radiation, thereby reheating the universe, generating the baryon asymmetry of the universe and setting the stage for the thermal production of gravitinos. The B-L phase transition along with the (s)neutrino-driven reheating process hence represents an intriguing and testable mechanism to generate the initial conditions of the hot early universe. We study the B-L phase transition in the full supersymmetric Abelian Higgs model, for which we derive and discuss the Lagrangian in arbitrary and unitary gauge. As for the subsequent reheating process, we formulate the complete set of Boltzmann equations, the solutions of which enable us to give a detailed and time-resolved description of the evolution of all particle abundances during reheating. Assuming the gravitino to be the lightest superparticle (LSP), the requirement of consistency between hybrid inflation, leptogenesis and gravitino dark matter implies relations between neutrino parameters and superparticle masses, in particular a lower bound on the gravitino mass of 10GeV. As an alternative to gravitino dark matter, we consider the case of

  11. Effect of medium chain triglycerides on brown adipose tissue in C57BL/6J mice%中链甘油三酯对C57BL/6J小鼠棕色脂肪组织的影响

    Institute of Scientific and Technical Information of China (English)

    张永; 刘英华; 张新胜; 于晓明; 徐庆; 王觐; 宫雪; 杨雪艳; 薛长勇

    2011-01-01

    Objective To study the effect of medium chain triglycerides(MCT) on brown adipose tissue(BAT) in C57BL/6J mice. Methods Thirty male C57BL/6J mice at the age 4-5 weeks, enrolled in this study, were randomly divided into MCT group, LCT group and control group( 10 in each group). Animals in the first two groups were fed with high fat diet containing MCT or LCT, and those in control group were fed with standard chow for 15 weeks. Body weight, subscapular brown fat mass, diet consumption, and uncoupled protein-1(UCP1) expression in BAT of different groups were observed. Results After 15 weeks, the body weight and body fat mass were significantly lower in MCT group than in LCT group(P0.05). The brown fat mass and UCP1 expression were significantly higher in MCT group than in LCT group(P<0.05). Conclusion MCT can inhibit the increase of body mass and accumulation of body fat due to high fat diet by increasing brown fat mass, UCP1 expression and heat production in brown fat tissue.%目的 观察中链甘油三酯(MCT)对C57BL/6J小鼠棕色脂肪组织的影响.方法 选择4-5周龄C57BL/6J雄性小鼠30只,随机分为中链甘油三酯高脂组(MCT),大豆油高脂组(LCT)及普通饲料对照组,每组10只,喂饲15周.观察研究前后各组间小鼠体质量、饲料消耗量及食物功效比、棕色脂肪组织重量差异以及解偶联蛋白-1(UCP1)表达水平的变化.结果 研究结束时,MCT高脂组小鼠的体质量、体脂肪量显著低于LCT组(P<0.05),饲料消耗量MCT组和LCT组之间无统计学差异(P>0.05),MCT组棕色脂肪组织重量及UCP1蛋白表达量显著高于LCT组.结论 MCT可促进棕色脂肪组织增殖,提高棕色脂肪组织UCP1的表达,增强棕色脂肪组织的产热功能,从而抑制高脂饲料诱发的C57BL/6J小鼠体质量增加和体脂肪积累.

  12. C57BL/6J及NIH Swiss小鼠在抑郁模型中的行为学表现%Behavioral manifestations in animal models with depression between C57BL/6J and NIH Swiss mice

    Institute of Scientific and Technical Information of China (English)

    李亮萍; 王倩; 潘彦伶; 张怡慧; 魏佳优; 陈翌华; 高天明

    2012-01-01

    Objective To investigate behavioral differences in models with depression between C57BL/6J and NIH Swiss mice with different genetic backgrounds,to provide references for selection of examination animals in anti- depression drug researches,and to provide the useful animal models for invcstigating the effects of genetic factors on occurrence of depression.Methods Behavioral manifestations of depression in C57BI/6J and NIH Swiss mice (n=14 each) were detected under stress conditions using forced swimming test and tail suspension test.Open field test was used to detect the spontaneous motility of two kinds of mice.Results The immobility time of C57BL/6J mice was significantly longer than that of NIH Swiss mice [ (133.198 ± 5.749) s vs (80.265± 10.939) s,P=0.000] in forced swimming test,which was contrast to that in tail suspension test [ (151.315±12.161)s vs (95.107±14.649)s,P=0.007].Howevcr in open field test,no diffcrcncc was found in total distance,standing number,movement time,total distance in fringe area,movement time in fringe area,total distance in central area and movement time in central area between the two kinds of mice.Conclusion C57BL/6J mice are easier to show the depressive-like behavior under stress conditions,while NIH Swiss mice show a certain of depression resistance.These different behavioral manifestations in two different kinds of mice may be caused by genetic factors.%目的 探讨两种不同遗传背景的小鼠C57BL/6J及NIH Swiss在抑郁模型中的行为学差异,为抗抑郁药物研究的实验动物选择提供参考,为研究遗传学因素在抑郁症发病过程中的作用提供有用的动物模型.方法 C57BL/6J、NIH Swiss小鼠各14只,利用强迫游泳实验和悬尾实验检测两种小鼠在应激条件下的抑郁样行为表现;利用旷场实验检测两种小鼠的自主运动能力.结果 强迫游泳实验中,C57BL/6J小鼠的不动时间明显长于NIH Swiss小鼠[(133.198±5.749)s比(80.265±10.939)s,P=0

  13. A comparative study of the progression of radiation pulmonary injury in C57BL/6J and C3H/HeN mice

    International Nuclear Information System (INIS)

    Objective: To compare the course of radiation pulmonary injury in C57BL/6J and C3H/HeN mice. Methods: C57BL/6J and C3H/HeN mice irradiated with 20 Gy 60Co gamma rays were used as animal models. Sirius red staining and hydroxyproline measurement were used to detect the distribution of type I and III collagens and the content of pulmonary hydroxyproline. Immunohistochemistry was used to observe the changes of the expressions of fibronectin (FN) and laminin (LN) and alpha-smooth muscle actin (α-SMA) in the lung. Results: The changes in the lungs in C57BL/6J mice were as follows: the pathological changes undergone interstitial pneumonia, proliferation and fibrosis; significant increase of collagen deposition; FN increased rapidly to a significantly higher level at 1 and 3 months after irradiation than that in the control (P<0.01), and then decreased gradually to a normal level at 6 month after irradiation; LN elevated gradually after irradiation; the expressions of α-SMA were more intense than that in C3H/HeN mice. The changes in the lungs in C3H/HeN mice were as follows: the pathological changes mainly developed institial pneumonitis; no significant changes of FN expression was observed after irradiation compared to that in the control; LN increased significantly at 1 and 3 months after irradiation, and then decreased gradually. Conclusions: The models of radiation pulmonary fibrosis-sensitive and-resistant were established by irradiation with gamma rays, C57BL/6J mice developed late radiation pulmonary fibrosis, and were characterized by the significant accumulation of collagen. C3H/HeN mice did not develop radiation pulmonary fibrosis. (authors)

  14. Quinine controls body weight gain without affecting food intake in male C57BL6 mice

    Directory of Open Access Journals (Sweden)

    Cettour-Rose Philippe

    2013-02-01

    Full Text Available Abstract Background Quinine is a natural molecule commonly used as a flavouring agent in tonic water. Diet supplementation with quinine leads to decreased body weight and food intake in rats. Quinine is an in vitro inhibitor of Trpm5, a cation channel expressed in taste bud cells, the gastrointestinal tract and pancreas. The objective of this work is to determine the effect of diet supplementation with quinine on body weight and body composition in male mice, to investigate its mechanism of action, and whether the effect is mediated through Trpm5. Results Compared with mice consuming AIN, a regular balanced diet, mice consuming AIN diet supplemented with 0.1% quinine gained less weight (2.89 ± 0.30 g vs 5.39 ± 0.50 g and less fat mass (2.22 ± 0.26 g vs 4.33 ± 0.43 g after 13 weeks of diet, and had lower blood glucose and plasma triglycerides. There was no difference in food intake between the mice consuming quinine supplemented diet and those consuming control diet. Trpm5 knockout mice gained less fat mass than wild-type mice. There was a trend for a diet-genotype interaction for body weight and body weight gain, with the effect of quinine less pronounced in the Trpm5 KO than in the WT background. Faecal weight, energy and lipid contents were higher in quinine fed mice compared to regular AIN fed mice and in Trpm5 KO mice compared to wild type mice. Conclusion Quinine contributes to weight control in male C57BL6 mice without affecting food intake. A partial contribution of Trpm5 to quinine dependent body weight control is suggested.

  15. Does black hole spin play a key role in the FSRQ/BL Lac dichotomy?

    Science.gov (United States)

    Bhattacharya, Debbijoy; Sreekumar, Parameswaran; Mukhopadhyay, Banibrata; Tomar, Ishan

    2016-04-01

    Blazars are characterized by large intensity and spectral variations across the electromagnetic spectrum It is believed that jets emerging from them are almost aligned with the line-of-sight. The majority of identified extragalactic sources in γ-ray catalogs of EGRET and Fermi are blazars. Observationally, blazars can be divided into two classes: flat spectrum radio quasars (FSRQs) and BL Lacs. BL Lacs usually exhibit lower γ-ray luminosity and harder power law spectra at γ-ray energies than FSRQs. We attempt to explain the high energy properties of FSRQs and BL Lacs from Fermi γ-ray space telescope observations. It was argued previously that the difference in accretion rates is mainly responsible for the large mismatch in observed luminosity in γ-ray. However, when intrinsic luminosities are derived by correcting for beaming effects, this difference in γ-ray luminosity between the two classes is significantly reduced. In order to explain this difference in intrinsic luminosities, we propose that spin plays an important role in the luminosity distribution dichotomy of BL Lacs and FSRQs. As the outflow power of a blazar increases with increasing spin of a central black hole, we suggest that the spin plays a crucial role in making BL Lac sources low luminous and slow rotators compared to FSRQ sources.

  16. Hypolipidemic effect of young persimmon fruit in C57BL/6.KOR-ApoEshl mice.

    Science.gov (United States)

    Matsumoto, Kenji; Yokoyama, Shin-ichiro; Gato, Nobuki

    2008-10-01

    We investigated the hypolipidemic effects of young persimmon fruit (YP) on apolipoprotein E-deficient C57BL/6.KOR-ApoEshl mice. These mice exhibited higher plasma cholesterols, except for high-density lipoprotein (HDL), and lower plasma HDL cholesterol than C57BL/6.Cr mice that had the same genetic background as the C57BL/6.KOR-ApoEshl mice. Male C57BL/6.KOR-ApoEshl mice (n=5) were fed a diet supplemented with dry YP, Hachiya-kaki, at a concentration of 5% (w/w) for 10 weeks. YP treatment significantly lowered plasma chylomicron, very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) cholesterols, and triglyceride, and this response was accompanied by an elevation of fecal bile acid excretion. In the liver, sterol regulatory element binding protein-2 gene expression was significantly higher in mice fed YP, while the mRNA and protein levels of the LDL receptor did not change. These results indicate that acceleration of fecal bile acid excretion is a major mechanism of the hypolipidemic effect induced by YP in C57BL/6.KOR-ApoEshl mice. PMID:18838807

  17. Setting and Achieving Objectives.

    Science.gov (United States)

    Knoop, Robert

    1986-01-01

    Provides basic guidelines which school officials and school boards may find helpful in negotiating, establishing, and managing objectives. Discusses characteristics of good objectives, specific and directional objectives, multiple objectives, participation in setting objectives, feedback on goal process and achievement, and managing a school…

  18. Scanning hard X-ray microscope with tantalum phase zone plate at the Hyogo-BL (BL24XU) of SPring-8

    International Nuclear Information System (INIS)

    A scanning hard X-ray microscope using a phase zone plate made of tantalum as its X-ray focusing device is in operation at the Hyogo-BL (BL24XU) of SPring-8. The X-ray microbeam has a size of 0.8 μmx0.7 μm at the photon energy of 10 keV, which can make visible structures as fine as 250-nm line-and-space pattern. The photon flux density at the sample position is ∼2x109 phs/s/μm2 and the gain of the phase zone plate is ∼3000. The minimum detection limits irradiated by the microbeam are evaluated to be around 10 ppm for some trace elements contained in standard reference materials of glass matrices. X-ray images obtained so far demonstrate a high feasibility of the microscope

  19. Dark matter scenarios in the minimal SUSY B-L model

    CERN Document Server

    Basso, Lorenzo; Porod, Werner; Staub, Florian

    2012-01-01

    We perform a study of the dark matter candidates of a constrained version of the minimal R-parity-conserving supersymmetric model with a gauged $U(1)_{B-L}$. It turns out that there are four additional candidates for dark matter in comparison to the MSSM: two kinds of neutralino, which either correspond to the gaugino of the $U(1)_{B-L}$ or to a fermionic bilepton, as well as "right-handed" CP-even and -odd sneutrinos. The correct dark matter relic density of the neutralinos can be obtained due to different mechanisms including new co-annihilation regions and resonances. The large additional Yukawa couplings required to break the $U(1)_{B-L}$ radiatively often lead to large annihilation cross sections for the sneutrinos. The correct treatment of gauge kinetic mixing is crucial to the success of some scenarios. All candidates are consistent with the exclusion limits of Xenon100.

  20. Identification of salt-tolerant Sinorhizobium sp. strain BL3 membrane proteins based on proteomics

    DEFF Research Database (Denmark)

    Tanthanuch, Waraporn; Tittabutr, Panlada; Mohammed, Shabaz; Matthiesen, Rune; Yamabhai, Montarop; Manassila, Monchai; Jensen, Ole Noerregaard; Boonkerd, Nantakorn; Teaumroong, Neung

    2010-01-01

    Sinorhizobium sp. BL3 is a salt-tolerant strain that can fix atmospheric nitrogen in symbiosis with leguminous host plants under salt-stress conditions. Since cell membranes are the first barrier to environmental change, it is interesting to explore the membrane proteins within this protective...... barrier under salt stress. The protein contents of membrane-enriched fractions obtained from BL3 were analyzed by nanoflow liquid chromatography interfaced with electrospray ionization tandem mass spectrometry. A total of 105 membrane proteins were identified. These proteins could be classified into 17...... functional categories, the two biggest of which were energy production and conversion, and proteins not in clusters of orthologous groups (COGs). In addition, a comparative analysis of membrane proteins between salt-stressed and non-stressed BL3 cells was conducted using a membrane enrichment method and off...

  1. A new B-L model without right-handed neutrinos

    CERN Document Server

    Patra, Sudhanwa; Yaguna, Carlos E

    2016-01-01

    We propose and study a novel extension of the Standard Model based on the B-L gauge symmetry that can account for dark matter and neutrino masses. In this model, right-handed neutrinos are absent and the gauge anomalies are canceled instead by four chiral fermions with fractional B-L charges. After the breaking of $U(1)_{B-L}$, these fermions arrange themselves into two Dirac particles, the lightest of which is automatically stable and plays the role of the dark matter. We determine the regions of the parameter space consistent with the observed dark matter density and show that they can be partially probed via direct and indirect dark matter detection or collider searches at the LHC. Neutrino masses, on the other hand, can be explained by a variant of the type-II seesaw mechanism involving one of the two scalar fields responsible for the dark matter mass.

  2. Minimal gauged U(1) B-L model with spontaneous R parity violation.

    Science.gov (United States)

    Barger, Vernon; Pérez, Pavel Fileviez; Spinner, Sogee

    2009-05-01

    We study the minimal gauged U(1) B-L supersymmetric model and show that it provides an attractive theory for spontaneous R-parity violation. Both U(1) B-L and R parity are broken by the vacuum expectation value of the right-handed sneutrino (proportional to the soft supersymmetry masses), thereby linking the B-L and soft SUSY scales. In this context we find a consistent mechanism for generating neutrino masses and a realistic mass spectrum, all without extending the Higgs sector of the minimal supersymmetry standard model. We discuss the most relevant collider signals and the connection between the Z' gauge boson and R-parity violation. PMID:19518859

  3. Effects of natural raw meal (NRM) on high-fat diet and dextran sulfate sodium (DSS)-induced ulcerative colitis in C57BL/6J mice

    OpenAIRE

    Shin, Sung-Ho; Song, Jia-Le; Park, Myoung-Gyu; Park, Mi-Hyun; Hwang, Sung-Joo; Park, Kun-Young

    2015-01-01

    BACKGROUND/OBJECTIVES Colitis is a serious health problem, and chronic obesity is associated with the progression of colitis. The aim of this study was to determine the effects of natural raw meal (NRM) on high-fat diet (HFD, 45%) and dextran sulfate sodium (DSS, 2% w/v)-induced colitis in C57BL/6J mice. MATERIALS/METHODS Body weight, colon length, and colon weight-to-length ratio, were measured directly. Serum levels of obesity-related biomarkers, triglyceride (TG), total cholesterol (TC), l...

  4. Progression of Diet-Induced Diabetes in C57BL6J Mice Involves Functional Dissociation of Ca2+ Channels From Secretory Vesicles

    OpenAIRE

    Collins, Stephan C.; Hoppa, Michael B; Walker, Jonathan N.; Amisten, Stefan; Abdulkader, Fernando; Bengtsson, Martin; Fearnside, Jane; Ramracheya, Reshma; Toye, Ayo A.; Zhang, Quan; Clark, Anne; Gauguier, Dominique; Rorsman, Patrik

    2010-01-01

    OBJECTIVE The aim of the study was to elucidate the cellular mechanism underlying the suppression of glucose-induced insulin secretion in mice fed a high-fat diet (HFD) for 15 weeks. RESEARCH DESIGN AND METHODS C57BL6J mice were fed a HFD or a normal diet (ND) for 3 or 15 weeks. Plasma insulin and glucose levels in vivo were assessed by intraperitoneal glucose tolerance test. Insulin secretion in vitro was studied using static incubations and a perfused pancreas preparation. Membrane currents...

  5. Object models and object representation Tutorial 4

    CERN Document Server

    CERN. Geneva; Mahey, Mahendra

    2007-01-01

    This tutorial will provide a practical overview of current practices in modelling complex or compound digital objects. It will examine some of the key scenarios around creating complex objects and will explore a number of approaches to packaging and transport. Taking research papers, or scholarly works, as an example, the tutorial will explore the different ways in which these, and their descriptive metadata, can be treated as complex objects. Relevant application profiles and metadata formats will be introduced and compared, such as Dublin Core, in particular the DCMI Abstract Model, and MODS, alongside content packaging standards, such as METS MPEG 21 DIDL and IMS CP. Finally, we will consider some future issues and activities that are seeking to address these. The tutorial will be of interest to librarians and technical staff with an interest in metadata or complex objects, their creation, management and re-use.

  6. Synchrotron total reflection X-ray fluorescence at BL-16 microfocus beamline of Indus-2

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, M. K., E-mail: mktiwari@rrcat.gov.in; Singh, A. K., E-mail: mktiwari@rrcat.gov.in; Das, Gangadhar, E-mail: mktiwari@rrcat.gov.in; Chowdhury, Anupam, E-mail: mktiwari@rrcat.gov.in; Lodha, G. S., E-mail: mktiwari@rrcat.gov.in [Indus Synchrotrons Utilisation Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

    2014-04-24

    Determination of ultra trace elements is important in many disciplines both in basic and applied sciences. Numerous applications show their importance in medical science, environmental science, materials science, food processing and semiconductor industries and in maintaining the quality control of ultra pure chemicals and reagents. We report commissioning of a synchrotron based total reflection x-ray fluorescence (TXRF) facility on the BL-16 microfocus beamline of Indus-2. This paper describes the performance of the BL-16 TXRF spectrometer and the detailed description of its capabilities through examples of measured results.

  7. Synchrotron total reflection X-ray fluorescence at BL-16 microfocus beamline of Indus-2

    International Nuclear Information System (INIS)

    Determination of ultra trace elements is important in many disciplines both in basic and applied sciences. Numerous applications show their importance in medical science, environmental science, materials science, food processing and semiconductor industries and in maintaining the quality control of ultra pure chemicals and reagents. We report commissioning of a synchrotron based total reflection x-ray fluorescence (TXRF) facility on the BL-16 microfocus beamline of Indus-2. This paper describes the performance of the BL-16 TXRF spectrometer and the detailed description of its capabilities through examples of measured results

  8. Treatment of Postpartum Retention of Urine by Needling Shenshu (BL 23)

    Institute of Scientific and Technical Information of China (English)

    ZHANG ke-bin; CUI Yi-jun

    2003-01-01

    @@ ●Acupoints: Shenshu (BL 23) and Sanyinjiao (SP 6) ●Manipulation: The patient was required to take a prone position. Shenshu (BL 23) was 1.5 cun lateral to the point which was below the spinous process of the second lumbar vertebra. After the skin was sterilized routinely, a filiform needle of 0.45 mm in diameter was perpendicularly inserted into skin and to a depth of 2.5 - 3 cun and the needling sensation should be required to radiate to the perineum.

  9. Electron EDM and soft leptogenesis in supersymmetric B-L extension of the standard model

    OpenAIRE

    Kajiyama, Yuji; Khalil, Shaaban; Raidal, Martti

    2009-01-01

    We analyze the connection between electric dipole moment of the electron and the soft leptogenesis in supersymmetric $B-L$ extension of the standard model. In this model, the $B-L$ symmetry is radiatively broken at TeV scale. Therefore, it is a natural framework for low scale seesaw mechanism and also for implementing the soft leptogenesis. We show that the phases of trilinear soft SUSY breaking couplings $A$, which are relevant for the lepton asymmetry, are not constrained by the present exp...

  10. Resonant Leptogenesis in the Minimal B-L Extended Standard Model at TeV

    OpenAIRE

    Iso, Satoshi; Okada, Nobuchika; Orikasa, Yuta

    2010-01-01

    We investigate the resonant leptogenesis scenario in the minimal B-L extended standard model(SM) with the B-L symmetry breaking at the TeV scale. Through detailed analysis of the Boltzmann equations, we show how much the resultant baryon asymmetry via leptogenesis is enhanced or suppressed, depending on the model parameters, in particular, the neutrino Dirac Yukawa couplings and the TeV-scale Majorana masses of heavy degenerate neutrinos. In order to consider a realistic case, we impose a sim...

  11. Paradigms in object recognition

    International Nuclear Information System (INIS)

    A broad range of approaches has been proposed and applied for the complex and rather difficult task of object recognition that involves the determination of object characteristics and object classification into one of many a priori object types. Our paper revises briefly the three main different paradigms in pattern recognition, namely Bayesian statistics, neural networks, and expert systems. (author)

  12. Early object rule acquisition.

    Science.gov (United States)

    Pierce, D E

    1991-05-01

    The purpose of this study was to generate a grounded theory of early object rule acquisition. The grounded theory approach and computer coding were used to analyze videotaped samples of an infant's and a toddler's independent object play, which produced the categories descriptive of three primary types of object rules; rules of object properties, rules of object action, and rules of object affect. This occupational science theory offers potential for understanding the role of objects in human occupations, for development of instruments, and for applications in occupational therapy early intervention. PMID:2048625

  13. Polarimetry and photometry of active quasars at visual and near-infrared wavelengths

    International Nuclear Information System (INIS)

    The optical and near-infrared continua of highly luminous BL Lacertae (BL Lac) objects and optically violent variable (OVV) quasars are studied through simultaneous broad-band photometry and linear polarimetry. Nineteen BL Lacs and OVVs were monitored during a ∼1 1/2-year period, with the major aim of characterizing the wavelength-dependent polarization exhibited by these objects. Optical (UBVRI) observations were conducted at the UCSD/U. Minn. 1.5-m telescope on Mt. Lemmon, Arizona. Simultaneous (within 1 hr.) near-infrared (JHK) measurements were made using the KPNO 2.1-m telescope. Most of the BL Lac objects exhibit large variations in polarization and brightness on time scale of less than a week. The degree of fractional linear polarization (P) is not observed to be related to brightness or optical spectral index. Most BL Lacs did not show a preferred polarization position angle (theta). Wavelength-dependent P and theta are observed in almost all BL Lacs, but not always simultaneously. The OVV quasar 1156 + 295 shows behavior very similar to the BL Lac objects. 3C 345 Exhibited polarization properties that are quite different from those of the BL Lacs. This object showed a clear correlation between brightness and P

  14. Conceivability Theses and Objections

    DEFF Research Database (Denmark)

    will try to provide an overview also of the different objections that have been and are leveled at the conceivability theses. A number of these are problems for an epistemology of modality generally. I will focus on the objections that are peculiar to conceivability theses: the Standard Objection...... and the Uselessness Objection. The Standard Objection targets the second premise in an argument for possibility from conceivability, that what is conceived is possible, typically by offering counterexamples in the form of conceivable impossibilities. The Uselessness Objection targets the first premise in an argument...

  15. Right-handed neutrino dark matter under the B-L gauge interaction

    CERN Document Server

    Kaneta, Kunio; Lee, Hye-Sung

    2016-01-01

    We study the right-handed neutrino (RHN) dark matter candidate in the minimal U(1)_{B-L} gauge extension of the standard model. The U(1)_{B-L} gauge symmetry offers three RHNs which can address the origin of the neutrino mass, the relic dark matter, and the matter-antimatter asymmetry of the universe. The lightest among the three can be a sufficiently long-lived dark matter candidate, without an additional stability mechanism, which is under the B-L gauge interaction. We investigate various scenarios for this dark matter candidate with the correct relic density by means of the freeze-out or freeze-in mechanism. A viable RHN dark matter mass lies in a wide range including keV to TeV scale. We emphasize the sub-electroweak scale light B-L gauge boson case, and identify the parameter region motivated from the dark matter physics, which can be tested with the planned experiments including the CERN SHiP experiment.

  16. Galactic Gamma Ray Excess and Dark Matter Phenomenology in a $U(1)_{B-L}$ Model

    CERN Document Server

    Biswas, Anirban; Khan, Sarif

    2016-01-01

    In this work, we have considered a gauged $U(1)_{\\rm B-L}$ extension of the Standard Model (SM) with three right handed neutrinos for anomaly cancellation and two additional SM singlet complex scalars with non-trivial B-L charges. One of these is used to spontaneously break the $U(1)_{\\rm B-L}$ gauge symmetry, leading to Majorana masses for the neutrinos through the standard Type I seesaw mechanism, while the other becomes the dark matter (DM) candidate in the model. We test the viability of the model to simultaneously explain the DM relic density observed in the CMB data as well as the Galactic Centre (GC) $\\gamma$-ray excess seen by Fermi-LAT. We show that for DM masses in the range 40-55 GeV and for a wide range of $U(1)_{\\rm B-L}$ gauge boson masses, one can satisfy both these constraints if the additional neutral Higgs scalar has a mass around the resonance region. In studying the dark matter phenomenology and GC excess, we have taken into account theoretical as well as experimental constraints coming fr...

  17. Dose calculation and measurement for bremsstrahlung at BL18U beamline of SSRF

    International Nuclear Information System (INIS)

    Background: Gas bremsstrahlung is one of the most important radiation sources that needs to be taken into consideration for shielding design of beamlines at the third generation synchrotron radiation light source. Shanghai Synchrotron Radiation Facility (SSRF) is one of the third generation synchrotron radiation light source in the world. The Protein Micro-crystallography Beamline (BL18U) is one of the commissioning beamlines and is a representative insertion device beamline at SSRF. Purpose: Estimation of radiation dose induced by scattering bremsstrahlung and photoneutrons at BL18U. Methods: Dose rate distribution induced by scattering bremsstrahlung and photoneutrons at BL18U are performed by Monte Carlo simulation code FLUKA. The radiation dose was analyzed with the variation of slits size, beam current at storage ring and the vacuum. Dose rate of photons and photoneutrons at the outside of the optical enclosure of BL18U were measured by using high sensitivity photon and neutron monitors. Results: The measurement results show that the reliability of the simulation. Conclusion: The simulation and measurement methods presented in this study can be applied to evaluate the dose rate level of other beamline stations at SSRF, and provide references to the shielding design for the following beamlines at SSRF in the near future. (authors)

  18. SPring-8 BL41XU, a high-flux macromolecular crystallography beamline

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Kazuya [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Shimizu, Nobutaka [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); KEK-PF, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Okumura, Hideo; Mizuno, Nobuhiro; Baba, Seiki [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Hirata, Kunio [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Takeuchi, Tomoyuki; Yamazaki, Hiroshi; Senba, Yasunori; Ohashi, Haruhiko [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Yamamoto, Masaki [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Kumasaka, Takashi, E-mail: kumasaka@spring8.or.jp [SPring-8/JASRI, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

    2013-11-01

    SPring-8 BL41XU provides a high-flux X-ray beam of size 10–50 µm, and enables high-quality diffraction data to be obtained from various types of protein crystals. Details of this beamline and an upgrade project are described. SPring-8 BL41XU is a high-flux macromolecular crystallography beamline using an in-vacuum undulator as a light source. The X-rays are monochromated by a liquid-nitrogen-cooling Si double-crystal monochromator, and focused by Kirkpatrick–Baez mirror optics. The focused beam size at the sample is 80 µm (H) × 22 µm (V) with a photon flux of 1.1 × 10{sup 13} photons s{sup −1}. A pinhole aperture is used to collimate the beam in the range 10–50 µm. This high-flux beam with variable size provides opportunities not only for micro-crystallography but also for data collection effectively making use of crystal volume. The beamline also provides high-energy X-rays covering 20.6–35.4 keV which allows ultra-high-resolution data to be obtained and anomalous diffraction using the K-edge of Xe and I. Upgrade of BL41XU for more rapid and accurate data collection is proceeding. Here, details of BL41XU are given and an outline of the upgrade project is documented.

  19. A Radiative Linear Seesaw, Dark Matter and $U(1)_{B-L}$

    CERN Document Server

    Wang, Weijian

    2015-01-01

    In this paper we propose a radiated linear seesaw model where the naturally small term $\\mu_{L}$ are generated at one-loop level and its soft-breaking of lepton number symmetry attributes to the spontaneous breaking(SSB) of B-L gauge symmetry. The value of $B-L$ charges for new particles are assigned to satisfy the anomalies cancelation. It is founded that some new particles may have exotic values of $B-L$ charge such that there exists residual $Z_{2}\\times Z_{2}^{\\prime}$ symmetry even after SSB of $B-L$ gauge symmetry. The $Z_{2}\\times Z_{2}^{\\prime}$ discrete symmetry stabilizes the these particles as dark matter candidates. In the model, two no-interplay classes of inert fermions and scalars are introduced, leading to two-component dark matter candidates. The lepton flavor violation processes, the relic density of dark matter, the direct detection of dark matter and the phenomenology on collider machine are investigated.

  20. Radiative Symmetry Breaking in the Supersymmetric Minimal B-L Extended Standard Model

    CERN Document Server

    Burell, Zachary

    2016-01-01

    The Standard Model (SM) of particle physics is a precise model of electroweak interactions, however there is growing tension between the SM and observations (neutrino oscillations, dark matter, dark energy, baryogenesis, among others). There is no reason to expect the validity of the ad hoc SM to remain intact at energy scales above a few TeV, thus a more fundamental theory will almost certainly be required. Motivated by these considerations, we investigate a Supersymmetric version of a natural extension of the SM, the $U(1)_{B-L}$ model, that is obtained by gauging the accidental B-L symmetry that exists in the ordinary SM. The Supersymmetric $U(1)_{B-L}$ extended SM can resolve the neutrino mass problem, the dark matter problem, the hierarchy problem, and provides a mechanism for establishing the observed baryon asymmetry of the Universe. When we include quantum corrections to the Higgs potential of the model, we find that Radiative $B-L$ symmetry breaking occurs through the interplay between large Majorana...

  1. The $B-L$ Supersymmetric Standard Model with Inverse Seesaw at the Large Hadron Collider

    CERN Document Server

    Khalil, S

    2015-01-01

    We review the TeV scale $B-L$ extension of the Minimal Supersymmetric Standard Model (BLSSM) where an inverse seesaw mechanism of light neutrino mass generation is naturally implemented and concentrate on its hallmark manifestations at the Large Hadron Collider (LHC).

  2. Macrophage-dependent clearance of systemically administered B16BL6-derived exosomes from the blood circulation in mice

    Directory of Open Access Journals (Sweden)

    Takafumi Imai

    2015-02-01

    Full Text Available Previous studies using B16BL6-derived exosomes labelled with gLuc–lactadherin (gLuc-LA, a fusion protein of Gaussia luciferase (a reporter protein and lactadherin (an exosome-tropic protein, showed that the exosomes quickly disappeared from the systemic circulation after intravenous injection in mice. In the present study, the mechanism of rapid clearance of intravenously injected B16BL6 exosomes was investigated. gLuc-LA-labelled exosomes were obtained from supernatant of B16BL6 cells after transfection with a plasmid DNA encoding gLuc-LA. Labelling was stable when the exosomes were incubated in serum. By using B16BL6 exosomes labelled with PKH26, a lipophilic fluorescent dye, it was demonstrated that PKH26-labelled B16BL6 exosomes were taken up by macrophages in the liver and spleen but not in the lung, while PKH26-labelled exosomes were taken up by the endothelial cells in the lung. Subsequently, gLuc-LA-labelled B16BL6 exosomes were injected into macrophage-depleted mice prepared by injection with clodronate-containing liposomes. The clearance of the intravenously injected B16BL6 exosomes from the blood circulation was much slower in macrophage-depleted mice than that in untreated mice. These results indicate that macrophages play important roles in the clearance of intravenously injected B16BL6 exosomes from the systemic circulation.

  3. Stress and estrous cycle affect strategy but not performance of female C57BL/6J mice

    NARCIS (Netherlands)

    J.P. ter Horst; J. Kentrop; E.R. de Kloet; M.S. Oitzl

    2013-01-01

    Stress induces a switch in learning strategies of male C57BL/6J mice from predominantly spatial to more stimulus-response learning. To study generalization of these findings over sex, we investigated female C57BL/6J mice at three phases of the estrous cycle under non stress and acute (10 min) restra

  4. Defining Learning Objectives

    Institute of Scientific and Technical Information of China (English)

    霍鑫红

    2014-01-01

    <正>This article attempts to introduce the teacher to developments in the area of specifying learning objectives.When you have studied this article carefully,you should be able to(a)distinguish between statements of aims and statements of objectives,(b)discuss the merits of writing objectives from the point of view of the learner,and(c)write both complete and abbreviated statements of learning objectives for different language skills,functions,and notions.

  5. X-ray beam stabilization at BL-17A, the protein microcrystallography beamline of the Photon Factory

    International Nuclear Information System (INIS)

    BL-17A is a new structural biology beamline at the Photon Factory, dedicated to protein crystallography of microcrystals. Here the X-ray beam stabilization techniques used at BL-17A are described. BL-17A is a new structural biology beamline at the Photon Factory, Japan. The high-brilliance beam, derived from the new short-gap undulator (SGU-17), allows for unique protein crystallographic experiments such as data collection from microcrystals and structural determination using softer X-rays. However, microcrystal experiments require robust beam stability during data collection and minor fluctuations could not be ignored. Initially, significant beam instability was observed at BL-17A. The causes of the beam instability were investigated and its various sources identified. Subsequently, several effective countermeasures have been implemented, and the fluctuation of the beam intensity successfully suppressed to within 1%. Here the instability reduction techniques used at BL-17A are presented

  6. Survivability via Control Objectives

    Energy Technology Data Exchange (ETDEWEB)

    CAMPBELL,PHILIP L.

    2000-08-11

    Control objectives open an additional front in the survivability battle. A given set of control objectives is valuable if it represents good practices, it is complete (it covers all the necessary areas), and it is auditable. CobiT and BS 7799 are two examples of control objective sets.

  7. Learning Objects and Gerontology

    Science.gov (United States)

    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…

  8. Deductive Object Programming

    OpenAIRE

    Colonna, Francois

    2006-01-01

    We propose some slight additions to O-O languages to implement the necessary features for using Deductive Object Programming (DOP). This way of programming based upon the manipulation of the Production Tree of the Objects of Interest, result in making Persistent these Objects and in sensibly lowering the code complexity.

  9. Detecting a Moving Object

    Directory of Open Access Journals (Sweden)

    Archana Sidhanti

    2013-02-01

    Full Text Available Object tracking in video aims at detecting the appearances of an object and also the position of a moving object in a video sequence. Complex and dynamic scenes in video and television broadcasting have been a challenge for computerization of both in terms of storage and interaction. Scenes can be complex wherein there are many cluttered objects with different sizes, shapes, colors and can be dynamic with multiple interacting moving objects in a constantly changing background. Examples of such videos abound in applications like sports, air traffic, car traffic and cloud transformations etc.

  10. Per Object statistical analysis

    DEFF Research Database (Denmark)

    Groom, Geoffrey Brian

    2008-01-01

    This RS code is to do Object-by-Object analysis of each Object's sub-objects, e.g. statistical analysis of an object's individual image data pixels. Statistics, such as percentiles (so-called "quartiles") are derived by the process, but the return of that can only be a Scene Variable, not an Object...... Variable. This procedure was developed in order to be able to export objects as ESRI shape data with the 90-percentile of the Hue of each object's pixels as an item in the shape attribute table. This procedure uses a sub-level single pixel chessboard segmentation, loops for each of the objects of a...... specific class in turn, and uses as pair of PPO stages to derive the statistics and then assign them to the objects' Object Variables. It may be that this could all be done in some other, simply way, but several other ways that were tried did not succeed. The procedure ouptut has been tested against an...

  11. Chenodesoxycholic acid up-regulates fibroblast growth factor 21 and its effect on C57BL/6 mice%CDCA在C57BL/6小鼠中上调肝脏成纤维细胞生长因子21表达及其效应

    Institute of Scientific and Technical Information of China (English)

    刘小花; 王永超; 李良鹏; 彭家和; 江渝; 刘智敏

    2012-01-01

    目的 研究法尼酯X受体(farnesoidXreceptor,FXR)的激活对C57 BL/6小鼠肝脏中纤维细胞生长因子2( fibroblast growth factor 21,FGF21)基因表达的影响.方法 将18只3~4周龄C57BL/6小鼠随机分为3组,分别使用不同浓度鹅脱氧胆酸(chenodeoxy cholic acid,CDCA,0、10 mg/kg和50 mg/kg)给小鼠灌胃7d,处死后分别提取小鼠肝脏总RNA和总蛋白,采用RT-PCR法和Western blot法检测各组小鼠FGF21 RNA和蛋白表达水平的变化;同时用酶法测定检测小鼠血甘油三酯(TG)、胆固醇(TC)及血糖( GLU)变化.结果 C57BL/6小鼠肝脏中FGF21 RNA和蛋白的表达水平呈CDCA剂量依赖型增高;小鼠血脂及血糖测定结果显示:TG,TC和血糖随CDCA浓度的升高而下降.结论 CDCA可上调C57BL/6小鼠肝脏中FGF21的表达并导致血TG、TC及GLU下降.%Objective To determine the activation of the farnesoid X receptor (FXR) on the expression of fibroblast growth factor 21 (FGF21) in C57BL/6 mice. Methods A total of 18 male C57BL/6 mice (3 to 4 weeks old) were randomly divided into 3 groups and treated with FXR agonist, chenodesoxycholic acid ( CDC A) at different doses of 0, 10, and 50 mg/kg respectively for a week. After the treatment, the mice was sacrificed for their liver tissue. RT-PCR and Western blotting were performed to test the expression of FGF21 at mRNA and protein levels in the liver tissue. Blood triglycerides (TG), cholesterol (TC) and blood glucose (GLU) were measured by enzymatic determination test. Results FXR agonist CDC A up-regulated the FGF21 at mRNA and protein levels in a dose-dependent manner in C57BL/6 liver tissue after treatment for a week. While, blood concentrations of TG, TC and GLU were decreased with the increase of CDCA doses. Conclusion CDC A up-regulates FGF21 expression in C57/BL6 mice liver and results in a decrease in plasma TG, TC and blood glucose.

  12. Objects, materiality and meaning

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Lindegaard, Hanne

    2008-01-01

    The present research work investigates the relation between physical objects, their materiality, understood as the physical substances they are made from, and the communication from the objects. In product design of physical objects the communicative aspects are just as important as the function...... of the object, and the designers aim is therefore to tune both in order to achieve a desired goal. To do so the designer basically has 2 options: Alteration of the physical shape of the object and the selection of materials. Through the manipulation of shape and materials can symbolic and sensory information...... be written into the object. The materials are therefore carriers of communication, even though this is dependent of the cultural context and the environment which the object will be part of. However the designer has only minor influence on those....

  13. Birth of the Object: Detection of Objectness and Extraction of Object Shape through Object Action Complexes

    DEFF Research Database (Denmark)

    Kraft, Dirk; Pugeault, Nicolas; Baseski, Emre;

    2008-01-01

    We describe a process in which the segmentation of objects as well as the extraction of the object shape becomes realized through active exploration of a robot vision system. In the exploration process, two behavioral modules that link robot actions to the visual and haptic perception of objects...... interact. First, by making use of an object independent grasping mechanism, physical control over potential objects can be gained. Having evaluated the initial grasping mechanism as being successful, a second behavior extracts the object shape by making use of prediction based on the motion induced...... by the robot. This also leads to the concept of an "object" as a set of features that change predictably over different frames. The system is equipped with a certain degree of generic prior knowledge about the world in terms of a sophisticated visual feature extraction process in an early cognitive vision...

  14. Early object relations into new objects.

    Science.gov (United States)

    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

  15. A thioacetamide-induced hepatic encephalopathy model in C57BL/6 mice: a behavioral and neurochemical study Modelo de encefalopatia hepática induzida por tioacetamida em camundongos C57BL/6: estudo comportamental e neuroquímico

    OpenAIRE

    Aline Silva de Miranda; David Henrique Rodrigues; Luciene Bruno Vieira; Cristiano Xavier Lima; Milene Alvarenga Rachid; Paula Vieira Teixeira Vidigal; Marcus Vinicius Gomez; Helton José dos Reis; Cristina Guatimosim; Antônio Lúcio Teixeira

    2010-01-01

    OBJECTIVE: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome resulting from liver failure. In the present study, we aimed to standardize an animal model of HE induced by thioacetamide (TAA) in C57BL/6 mice evaluating behavioral symptoms in association with liver damage and alterations in neurotransmitter release. METHOD: HE was induced by an intraperitoneal single dose of TAA (200 mg/kg, 600 mg/kg or 1,200 mg/kg). Behavioral symptoms were evaluated using the SHIRPA battery. Liver dam...

  16. Metabolic deficiences revealed in the biotechnologically important model bacterium Escherichia coli BL21(DE3.

    Directory of Open Access Journals (Sweden)

    Constanze Pinske

    Full Text Available The Escherichia coli B strain BL21(DE3 has had a profound impact on biotechnology through its use in the production of recombinant proteins. Little is understood, however, regarding the physiology of this important E. coli strain. We show here that BL21(DE3 totally lacks activity of the four [NiFe]-hydrogenases, the three molybdenum- and selenium-containing formate dehydrogenases and molybdenum-dependent nitrate reductase. Nevertheless, all of the structural genes necessary for the synthesis of the respective anaerobic metalloenzymes are present in the genome. However, the genes encoding the high-affinity molybdate transport system and the molybdenum-responsive transcriptional regulator ModE are absent from the genome. Moreover, BL21(DE3 has a nonsense mutation in the gene encoding the global oxygen-responsive transcriptional regulator FNR. The activities of the two hydrogen-oxidizing hydrogenases, therefore, could be restored to BL21(DE3 by supplementing the growth medium with high concentrations of Ni²⁺ (Ni²⁺-transport is FNR-dependent or by introducing a wild-type copy of the fnr gene. Only combined addition of plasmid-encoded fnr and high concentrations of MoO₄²⁻ ions could restore hydrogen production to BL21(DE3; however, to only 25-30% of a K-12 wildtype. We could show that limited hydrogen production from the enzyme complex responsible for formate-dependent hydrogen evolution was due solely to reduced activity of the formate dehydrogenase (FDH-H, not the hydrogenase component. The activity of the FNR-dependent formate dehydrogenase, FDH-N, could not be restored, even when the fnr gene and MoO₄²⁻ were supplied; however, nitrate reductase activity could be recovered by combined addition of MoO₄²⁻ and the fnr gene. This suggested that a further component specific for biosynthesis or activity of formate dehydrogenases H and N was missing. Re-introduction of the gene encoding ModE could only partially restore the

  17. 近交系小鼠C57BL/6和C57BL/10的转录组差异研究%Transcriptome profile difference between C57BL/6 and C57BL/10 inbred mouse strains

    Institute of Scientific and Technical Information of China (English)

    陈航; 岳秉飞

    2016-01-01

    目的:对近交系小鼠C57BL/6和C57BL/10进行转录组测序,对比其转录组差异,发现免疫反应相关差异基因,为药物体内活性评价动物选择提供参考.方法:采用Illumina Hiseq 2000测序平台进行测序,通过短序列分析获取转录本,通过基因功能分类(GO)和京都基因与基因组百科全书(KEGG)数据库进行测序结果分析.结果:获得38 553 614个C57BL/6小鼠的原始序列和37 721 318个C57BL/10小鼠的原始序列.获得118 002个转录本,注释了46 193个差异基因.38 106个转录本注释到2 196个GO分类中,GO分类主要分为3类:细胞成分,分子功能和生物过程.1 600个转录本注释到254个KEGG通路中.另外,发现了4 651个单核苷酸(SNP)位点.结论:通过二代测序方法发现近交系小鼠C57BL/6和C57BL/10转录组存在显著差异基因.在KEGG通路分析中筛选了一系列与小鼠免疫应答相关的差异基因,为建立小鼠免疫评价模型积累了数据,对药物实验动物体内活性检测分析具有参考意义,为生物制品评价用实验动物的标准化提供技术支撑.

  18. Herbig-Haro objects

    Science.gov (United States)

    Boehm, K. H.

    1990-01-01

    The IUE (International Ultraviolet Explorer) spectra of Herbig-Haro (HH) objects and their relation to the very detailed optical spectra available for these objects are studied. Useful information about the physics of HH objects in general and especially about their hydrodynamic models which are contained in these IUE observations is outlined. The merged spectra of high excitation, low excitation HH objects (like HH43 and HH47), and peculiar HH objects are discussed. Results of the spatial variation of lines and continua in HH objects are discussed. Their compatibility with predictions for aerodynamic and especially bow shock models is discussed. The problems arising in the interpretation of the continuous energy distribution in the short wavelength range are discussed. They require the presence of other emission mechanisms in addition to the collisionally enhanced two photon continuum. In HH43 the fluorescent H2 line emission comes from a surprisingly small spatial region. Implications of these results are discussed.

  19. Reasoning about Function Objects

    Science.gov (United States)

    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.

  20. Extracts of pomelo peels prevent high-fat diet-induced metabolic disorders in c57bl/6 mice through activating the PPARα and GLUT4 pathway.

    Directory of Open Access Journals (Sweden)

    Xiaobo Ding

    Full Text Available OBJECTIVE: Metabolic syndrome is a serious health problem in both developed and developing countries. The present study investigated the anti-metabolic disorder effects of different pomelo varieties on obese C57BL/6 mice induced by high-fat (HF diet. DESIGN: The peels of four pomelo varieties were extracted with ethanol and the total phenols and flavonoids content of these extracts were measured. For the animal experiment, the female C57BL/6 mice were fed with a Chow diet or a HF diet alone or supplemented with 1% (w/w different pomelo peel extracts for 8 weeks. Body weight and food intake were measured every other day. At the end of the treatment, the fasting blood glucose, glucose tolerance and insulin (INS tolerance test, serum lipid profile and insulin levels, and liver lipid contents were analyzed. The gene expression analysis was performed with a quantitative real-time PCR assay. RESULT: The present study showed that the Citrus grandis liangpinyou (LP and beibeiyou (BB extracts were more potent in anti-metabolic disorder effects than the duanshiyou (DS and wubuyou (WB extracts. Both LP and BB extracts blocked the body weight gain, lowered fasting blood glucose, serum TC, liver lipid levels, and improved glucose tolerance and insulin resistance, and lowered serum insulin levels in HF diet-fed mice. Compared with the HF group, LP and BB peel extracts increased the mRNA expression of PPARα and its target genes, such as FAS, PGC-1α and PGC-1β, and GLUT4 in the liver and white adipocyte tissue (WAT. CONCLUSION: We found that that pomelo peel extracts could prevent high-fat diet-induced metabolic disorders in C57BL/6 mice through the activation of the PPARα and GLUT4 signaling. Our results indicate that pomelo peels could be used as a dietary therapy and the potential source of drug for metabolic disorders.

  1. Workshop; Goals and objectives

    International Nuclear Information System (INIS)

    One of the objectives of the workshop was to improve awareness of the international illicit nuclear trafficking information exchange mechanism, i.e. IAEA illicit nuclear trafficking database programme, its goals and objectives, reporting requirements and participation. Other objectives are: to enhance awareness of global and regional risk trends and patterns, share knowledge and assessment of regional developments, share methodology of the illicit nuclear trafficking information analysis and discuss ways for improving national and international illicit trafficking information management and coordination

  2. Composing concurrent objects

    OpenAIRE

    Bergmans, Louis Marie Johannes

    1994-01-01

    Adopting the object-oriented paradigm for the development of large and complex software systems offers several advantages, of which increased extensibility and reusability are the most prominent ones. The object-oriented model is also quite suitable for modelling concurrent systems. However, it appears that extensibility and reusability of concurrent applications is far from trivial. In addition, very little attention has been paid by the conventional object-oriented development methodologies...

  3. OBJECT ORIENTED DESIGN HEURISTICS

    OpenAIRE

    DEEPALI GUPTA; Mr. RAKESH KUMAR

    2011-01-01

    Object-oriented design is a process of identifying relevant objects, factoring them into classes, organizing hierarchically, and establishing dynamic collaborations among the objects. It is a difficult process especially for novice designers. In order to guide the novices, software engineers used some hints, guidelines and tips to communicate design experience from the expert. Design heuristic is common solution to design problems that developers encounter during software development. Heurist...

  4. Confinement for Active Objects

    OpenAIRE

    Florian Kammuller

    2014-01-01

    In this paper, we provide a formal framework for the security of distributed active objects. Active objects com-municate asynchronously implementing method calls via futures. We base the formal framework on a security model that uses a semi-lattice to enable multi-lateral security crucial for distributed architectures. We further provide a security type system for the programming model ASPfun of functional active objects. Type safety and a confinement property are presented. ASPfun thus reali...

  5. Cultivating objects in interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2014-01-01

    This paper demonstrates how an initial indexing of objects through gesture and talk provides a residual basis for later indexical development across a stretch of discourse. I show how participants are able to perform an initial mobilization of affordances (Hutchby, 2001) of objects in the immediate...... the interactional resources which mundane everyday objects provide interactants in the multimodal design of their turns-at-talk. Although the objects which feature in the data – for example notepads, tables, computer monitors – have practical functions within the social ecology of these institutional settings...

  6. Objective-C

    CERN Document Server

    DeVoe, Jiva

    2011-01-01

    A soup-to-nuts guide on the Objective-C programming language. Objective-C is the language behind Cocoa and Cocoa Touch, which is the Framework of applications written for the Macintosh, iPod touch, iPhone, and iPad platforms. Part of the Developer Reference series covering the hottest Apple topics, this book covers everything from the basics of the C language to advanced aspects of Apple development. You'll examine Objective-C and high-level subjects of frameworks, threading, networking, and much more.: Covers the basics of the C language and then quickly moves onto Objective-C and more advanc

  7. Auto- and cross-correlation analysis of the QSOs radio wave intensity

    Science.gov (United States)

    Demin, S. A.; Panischev, O. Yu; Nefedyev, Yu A.

    2015-12-01

    We discuss here the Flicker-Noise Spectroscopy approach to studying astrophysical systems, for example the radio wave intensity of quasi-stellar object (QSO) 1641+399 and BL Lacertae (BL Lac) 0215+015 in different frequency ranges. The presented method allows to parameterize the study dynamics using a short set of characteristics. The considering sources have a significant differences in manifesting the non-stationary effects, dynamical intermittency and synchronization. The radio wave intensity dynamics of the BL Lac 0215+015 is characterized by well-defined set of natural frequencies, persistent behavior with low effects of non-stationarity and high level of frequency-phase synchronization. For dynamics of the QSO 1641+399 reverse occurs including the asymmetrical structure of cross-correlator. Our findings show that using the flicker-noise spectroscopy approach to studying astrophysical objects allows to carry out the more detail analysis of their behavior and evolution.

  8. Programs as Data Objects

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the Second Symposium on Programs as Data Objects, PADO 2001, held in Aarhus, Denmark, in May 2001. The 14 revised full papers presented were carefully reviewed and selected from 30 submissions. Various aspects of looking at programs as data objects...

  9. Near Earth Objects

    DEFF Research Database (Denmark)

    Wolff, Stefan

    2006-01-01

    , Near Earth Objects: Asteroids and comets following paths that bring them near the Earth. NEOs have collided with the Earth since its formation, some causing local devastation, some causing global climate changes, yet the threat from a collision with a near Earth object has only recently been recognised...

  10. Object oriented programming

    International Nuclear Information System (INIS)

    This paper is an introduction to object oriented programming techniques. It tries to explain the concepts by using analogies with traditional programming. The object oriented approach not inherently difficult, but most programmers find a relatively high threshold in learning it. Thus, this paper will attempt to convey the concepts with examples rather than explain the formal theory

  11. On Objects and Events

    DEFF Research Database (Denmark)

    Eugster, Patrick Thomas; Guerraoui, Rachid; Damm, Christian Heide

    2001-01-01

    This paper presents linguistic primitives for publish/subscribe programming using events and objects. We integrate our primitives into a strongly typed object-oriented language through four mechanisms: (1) serialization, (2) multiple sub typing, (3) closures, and (4) deferred code evaluation. We...

  12. Composing concurrent objects

    NARCIS (Netherlands)

    Bergmans, Louis Marie Johannes

    1994-01-01

    Adopting the object-oriented paradigm for the development of large and complex software systems offers several advantages, of which increased extensibility and reusability are the most prominent ones. The object-oriented model is also quite suitable for modelling concurrent systems. However, it appe

  13. On object-orientation

    NARCIS (Netherlands)

    B. Diertens

    2010-01-01

    Although object-orientation has been around for several decades, its key concept abstraction has not been exploited for proper application of object-orientation in other phases of software development than the implementation phase. We mention some issues that lead to a lot of confusion and obscurity

  14. From QCD instantons at HERA to electroweak B+L violation at VLHC

    International Nuclear Information System (INIS)

    This review emphasizes the close analogy between hard QCD instanton-induced chirality violating processes in deep-inelastic scattering and electroweak instanton-induced baryon plus lepton number (B+L) violating processes in Quantum Flavor Dynamics (QFD). Recent information about QCD instantons, both from lattice simulations and from the H1 experiment at HERA, can be used to learn about the fate of electroweak B+L violation at future high energy colliders in the hundreds of TeV regime, such as the projected very large hadron collider (VLHC). The cross-sections turn out to be unobservably small in a conservative fiducial kinematical region inferred from the above mentioned QCD-QFD analogy. An extrapolation - still compatible with lattice results and HERA - beyond this conservative limit indicates possible observability at VLHC. (orig.)

  15. Neutrino Mass and Dark Matter from Gauged $U(1)_{B-L}$ Breaking

    CERN Document Server

    Kanemura, Shinya; Sugiyama, Hiroaki

    2014-01-01

    We propose a new model where the Dirac mass term for neutrinos, the Majorana mass term for right-handed neutrinos, and the other new fermion masses arise via the spontaneous breakdown of the $U(1)_{B-L}$ gauge symmetry. The anomaly-free condition gives four sets of assignment of the B-L charge to new particles, and three of these sets have an associated global $U(1)_{DM}$ symmetry which stabilizes dark matter candidates. The dark matter candidates contribute to generating the Dirac mass term for neutrinos at the one-loop level. Consequently, tiny neutrino masses are generated at the two-loop level via a Type-I-Seesaw-like mechanism. We show that this model can satisfy current bounds from neutrino oscillation data, the lepton flavor violation, the relic abundance of the dark matter, and the direct search for the dark matter. This model would be tested at future collider experiments and dark matter experiments.

  16. Creating reference gene annotation for the mouse C57BL6/J genome assembly.

    Science.gov (United States)

    Mudge, Jonathan M; Harrow, Jennifer

    2015-10-01

    Annotation on the reference genome of the C57BL6/J mouse has been an ongoing project ever since the draft genome was first published. Initially, the principle focus was on the identification of all protein-coding genes, although today the importance of describing long non-coding RNAs, small RNAs, and pseudogenes is recognized. Here, we describe the progress of the GENCODE mouse annotation project, which combines manual annotation from the HAVANA group with Ensembl computational annotation, alongside experimental and in silico validation pipelines from other members of the consortium. We discuss the more recent incorporation of next-generation sequencing datasets into this workflow, including the usage of mass-spectrometry data to potentially identify novel protein-coding genes. Finally, we will outline how the C57BL6/J genebuild can be used to gain insights into the variant sites that distinguish different mouse strains and species. PMID:26187010

  17. Detection of biogenic amines in C57BL/6 mice brain by capillary electrophoresis electrokinetic supercharging.

    Science.gov (United States)

    Wang, Wei-feng; Ju, Fu-rong; Ran, Yan-li; Zhang, Hui-ge; Chen, Xing-guo

    2016-02-01

    Ischemic stroke is caused when blood flow to the brain is stopped and is a major cause of death and long term disability across the globe. Excessive release of neurotransmitters is triggered in the brain by ischemia that mediates neuronal damage and causes ischemic injury. In this study, a simple, sensitive, and on-line preconcentration capillary electrophoresis method based on electrokinetic supercharging (EKS) was developed for the determination of the biogenic amines including dopamine (DA), epinephrine (E), and norepinephrine (NE) in C57BL/6 mice brain. Under the optimized conditions, the analytes were concentrated and detected within 10 min. The detection limits for the analytes ranged from 0.42 to 0.57 ng mL(-1) for a mice brain matrix. With the proposed method, the analyses of three neurochemical amines in C57BL/6 mice brain tissue during cerebral ischemic/reperfusion had been performed successfully. PMID:26658278

  18. Simultaneous Multifrequency Observations of the BL Lac MS 0205.7+3509

    CERN Document Server

    Watson, D; McBreen, B; Smith, N; Tashiro, M; Foley, A R; Metcalfe, L; Beckmann, V; Sánchez, S F; Teraesranta, H

    1999-01-01

    Radio and optical observations of the possible microlensed BL Lac source MS 0205.7+3509 were obtained simultaneously with ASCA x-ray measurements in February 1997. A single power law model, with a photon index of 2.61, is an adequate fit to the ASCA data, once hydrogenic absorption in excess of the Galactic value is permitted, confirming a previous ROSAT measurement. On the basis of our simultaneous data we have determined MS 0205.7+3509 to be a typical x--ray selected BL Lac, with alpha_xox=-0.82. There is no indication of an inverse Compton (IC) component in the ASCA spectrum up to 10 keV. No evidence for variability on hour-long timescales is present in either the x-ray or the optical data. We discuss these results in the context of a gravitational microlensing scenario for MS 0205.7+3509.

  19. 小麦易位系1BL/1RS×7DL.7Ag的F2分子检测及其农艺和品质性状分析%F2 Molecular Detection and the Agronomic and Quality Traits of Chromosome Translocations 1BL/1RS× 7DL.7Ag in Common Wheat

    Institute of Scientific and Technical Information of China (English)

    李佳彬; 胡阳杰; 王宇娟; 宋全昊; 田芳慧; 李法计; 孙道杰

    2012-01-01

    The 1BL/1RS translocation and 7DL. 7Ag translocation have been widely used by wheat breeders to enhance agronomic performance and disease resistance. In the past decades,the introduction and application of 1BL/1RS translocation significantly increased yield potentials and adaptability in China;now it still plays an important role in wheat breeding and production. Currently,the positive effects of 7DL. 7Ag translocation in terms of increasing the yield have caused attention of wheat breeders over the world. The objective of this study was to analysis the effects of 1BL/1RS and 7DL. 7Ag chromosome translocations on the main agronomic,yield and quality traits in wheat. A total of 900 F2 population and F2:3 family derived from the cross 'Yunong 982'(1BL/1RS translocation)/wheatear(7DL. 7Ag translocation) were planted in Yan-gling of Shaanxi Province during 2009-2011. This study identified the chromosome translocation types of F2 population using SSR and STS. In addition,a total of 15 traits of the two parents,F2 population and F2:3 family, such as plant height, spike length, grain number per spike, thousand-grain weight, grain weight per spike and days from emerge to maturity,were investigated (this study took the agronomic traits of F2 population as a reference, the main agronomic traits of F2:3 family were this study's key point). The F-test and multiple comparisons of the agronomic traits of no-translocation lines,homozygous 1BL/1RS translocation lines,homozygous 7DL. 7Ag translocation lines and Double Translocation Lines (1BL/1RS, 7DL. 7Ag) in F2:3 family were done using the SAS8. 2 System. At the same time, the effects of 1BL/1RS translocation and 7DL. 7Ag translocation on wheat quality were tested. The results showed that;STS Lrl9130 maker and Xgwm428 marker were identified,which could effectively distinguish the heterozygous 7DL. 7Ag translocation from homozygous 7DL. 7Ag translocation when they were used together. In terms of agronomic traits and yield traits

  20. Cultivating objects in interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2014-01-01

    is chapter explores patterns of repeated orientations to physical objects in interactants’ visuo-spatial and haptic surround. A number of examples are presented from advice-giving activities in various institutional settings, where participants-in-interaction initially draw on material objects at...... hand while pursuing a particular line of explanation, and then return to these objects at later intervals. e analysis suggests that the objects are afforded representational properties through their being anchored to some referent in the talk, and that participants subsequently draw on these...... associations for describing, disambiguating or clarifying aspects of the relatively complex procedural frameworks discussed in the settings. is suggests that the temporal stability of material objects available to participants makes them an ideal resource to be developed as visual motifs....

  1. Moving Objects Updating

    Science.gov (United States)

    Chen, Jidong; Meng, Xiaofeng

    In moving objects applications, large numbers of locations can be sampled by sensors or GPS periodically, then sent from moving clients to the server and stored in a database. Therefore, continuously maintaining in a database the current locations of moving objects by using a tracking technique becomes very important. The key issue is minimizing the number of updates, while providing precise locations for query results. In this chapter, we will introduce some underlying location update methods. Then, we describe two location update strategies in detail, which can improve the performance. One is the proactive location update strategy, which predicts the movement of moving objects to lower the update frequency; the other is the group location update strategy, which groups the objects to minimize the total number of objects reporting their locations.

  2. Hardware Objects for Java

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Thalinger, Christian; Korsholm, Stephan;

    2008-01-01

    Java, as a safe and platform independent language, avoids access to low-level I/O devices or direct memory access. In standard Java, low-level I/O it not a concern; it is handled by the operating system. However, in the embedded domain resources are scarce and a Java virtual machine (JVM) without...... an underlying middleware is an attractive architecture. When running the JVM on bare metal, we need access to I/O devices from Java; therefore we investigate a safe and efficient mechanism to represent I/O devices as first class Java objects, where device registers are represented by object fields. Access...... to those registers is safe as Java’s type system regulates it. The access is also fast as it is directly performed by the bytecodes getfield and putfield. Hardware objects thus provide an object-oriented abstraction of low-level hardware devices. As a proof of concept, we have implemented hardware objects...

  3. OBJECT ORIENTED DESIGN HEURISTICS

    Directory of Open Access Journals (Sweden)

    DEEPALI GUPTA

    2011-01-01

    Full Text Available Object-oriented design is a process of identifying relevant objects, factoring them into classes, organizing hierarchically, and establishing dynamic collaborations among the objects. It is a difficult process especially for novice designers. In order to guide the novices, software engineers used some hints, guidelines and tips to communicate design experience from the expert. Design heuristic is common solution to design problems that developers encounter during software development. Heuristic is defined as the use of general knowledge gained by experience. Design heuristics are design experience from object-oriented developers. It is small and simpledesign expertise. This knowledge from the experienced designers is used to guide the novices. The purpose of this paper is to document design heuristics of object-oriented approach from literature study.

  4. Beginning Objective-C

    CERN Document Server

    Dovey, James

    2012-01-01

    Objective-C is today's fastest growing programming language, at least in part due to the popularity of Apple's Mac, iPhone and iPad. Beginning Objective-C is for you if you have some programming experience, but you're new to the Objective-C programming language and you want a modern-and fast-way forwards to your own coding projects. Beginning Objective-C offers you a modern programmer's perspective on Objective-C courtesy of two of the best iOS and Mac developers in the field today, and gets you programming to the best of your ability in this important language.  It gets you rolling fast into

  5. Comparison of bleomycin-induced pulmonary apoptosis between NMRI mice and C57BL/6 mice

    OpenAIRE

    Safaeian, L.; Jafarian-Dehkordi, A.; Rabbani, M.; Sadeghi, H.M.; Afshar-Moghaddam, N.; Sarahroodi, S.

    2013-01-01

    Apoptosis has a critical role in the pathogenesis of bleomycin induced-pulmonary fibrosis. The severity of fibrosis varies among different strains of mice. Recent studies have indicated that expression of apoptotic regulatory genes may be specific in different cell types in various strains. In this study, bleomycin-induced pulmonary apoptosis in NMRI (Naval Medical Research Institute, USA) albino mice were compared with C57BL/6 black mice. Pulmonary fibrosis induced by single intratracheal ad...

  6. Creating reference gene annotation for the mouse C57BL6/J genome assembly

    OpenAIRE

    Mudge, Jonathan M; Harrow, Jennifer

    2015-01-01

    Annotation on the reference genome of the C57BL6/J mouse has been an ongoing project ever since the draft genome was first published. Initially, the principle focus was on the identification of all protein-coding genes, although today the importance of describing long non-coding RNAs, small RNAs, and pseudogenes is recognized. Here, we describe the progress of the GENCODE mouse annotation project, which combines manual annotation from the HAVANA group with Ensembl computational annotation, al...

  7. Detection of outliers in BL(1,1,1,1 Models using Least Squares Method

    Directory of Open Access Journals (Sweden)

    Ibrahim Mohamed

    2006-07-01

    Full Text Available In the literature, various nonlinear time series data was shown to exist. As a result, studies on nonlinear models have been carried out. One of them is bilinear model. Further, there is a possibility that outliers may exist in the data. In this article, the possibility of an outlier appear in a special case of bilinear model, BL(1,1,1,1 is investigated. An outlier detection procedure is proposed.

  8. Denken in Kreisläufen:Lernerperspektiven zum Entwicklungszyklus von Blütenpflanzen

    OpenAIRE

    Benkowitz, D. (Dorothee); Lehnert, H

    2010-01-01

    In unserer vergleichenden Querschnittstudie haben wir die Vorstellungen zum pflanzlichen Entwicklungszyklus von Schülerinnen und Schülern unterschiedlicher Schulstufen (Jgst. 1, 6, 8) sowie von Studierenden erhoben. Im Rahmen leitfadenstrukturierter Einzelinterviews sollten unterschiedliche Entwicklungsstadien einer einjährigen Blütenpflanze geordnet und das Vorgehen begründet werden. Zusätzlich wurden ergänzende Fragen zur Herkunft von Pflanzen und Samen gestellt. Die Ergebnisse der Studi...

  9. A discussion of $Bl$ conservation on a two dimensional magnetic field plane in watt balances

    OpenAIRE

    Li, Shisong; Zhao, Wei; Huang, Songling

    2015-01-01

    The watt balance is an experiment being pursued in national metrology institutes for precision determination of the Planck constant $h$. In watt balances, the $1/r$ magnetic field, expected to generate a geometrical factor $Bl$ independent to any coil horizontal displacement, can be created by a strict two dimensional, symmetric (horizontal $r$ and vertical $z$) construction of the magnet system. In this paper, we present an analytical understanding of magnetic field distribution when the $r$...

  10. Protective immune response to experimental infection with Sarcocystis neurona in C57BL/6 mice

    OpenAIRE

    Witonsky, S. G.; Gogal, R. M.; Duncan, R. B.; Lindsay, D S

    2003-01-01

    Immunocompetent C57BL/6 mice were infected with Sarcocystis neurona merozoites to assess the protective immune response to active infection. Using a direct agglutination test, all infected mice seroconverted to S. neurona merozoite antigens by day 14 postinfection (PI). Further, mice developed splenomegaly and bilateral symmetrical lymphadenopathy by day 14 PI, which appeared to be resolving by day 28 PI. Histologic analysis revealed a marked increase in germinal center formation in the splee...

  11. Postoral Glucose Sensing, Not Caloric Content, Determines Sugar Reward in C57BL/6J Mice

    OpenAIRE

    Sclafani, Anthony; Zukerman, Steven; Ackroff, Karen

    2015-01-01

    Recent studies suggest that because of their energy value, sugars are more rewarding than non-caloric sweeteners. However, intragastric infusion data indicate that sugars differ in their postoral appetite-stimulating effects. We therefore compared the preference for isocaloric 8% sucrose, glucose, and fructose solutions with that of a non-caloric sweetener solution (0.8% sucralose) in C57BL/6J mice. Brief 2-bottle tests indicated that sucralose was isopreferred to sucrose but more preferred t...

  12. Escalated handling of young C57BL/6 mice results in altered Morris water maze performance

    OpenAIRE

    Fridgeirsdottir, Gudrun Andrea; Hillered, Lars; Clausen, Fredrik

    2014-01-01

    Background The handling of experimental animals prior to experimental interventions is often poorly described, even though it may affect the final functional outcome. This study explores how the use of repeated handling of C57BL/6 mice prior to Morris water maze (MWM) tests can affect the performance. Methods and materials The handled animals were subjected to the escalating handling protocol, with the investigator spending 5 min per day per cage for 8 days prior to the MWM test. On the last ...

  13. Etablierung der In-utero-Elektroporation des zentralen Nervensystems im Mausmodell C57BL/6

    OpenAIRE

    Baumgart, Jan

    2016-01-01

    This thesis describes new aspects in the development of the in-utero electroporation method (IUE) and hereby refers to the neurogenesis and the cortical migration in the central nervous system. With the assistance of the described transfection technique the development of neuronal stem cells could be manipulated in iso- and allocortex by regulating the expression of defined plasmides. The first section of this thesis examines the functionality and the validity of the IUE in the C57BL/6 wil...

  14. Neurobehavioral phenotype of C57BL/6J mice prenatally and neonatally exposed to cigarette smoke

    OpenAIRE

    Amos-Kroohs, Robyn M.; Williams, Michael T.; Braun, Amanda A.; Graham, Devon L.; WEBB, CYNTHIA L.; Birtles, Todd S.; Greene, Robert M.; Vorhees, Charles V.; Pisano, M. Michele

    2013-01-01

    Although maternal cigarette smoking during pregnancy is a well-documented risk factor for a variety of adverse pregnancy outcomes, how prenatal cigarette smoke exposure affects postnatal neurobehavioral/cognitive development remains poorly defined. In order to investigate the cause of an altered behavioral phenotype, mice developmentally exposed to a paradigm of ‘active’ maternal cigarette smoke is needed. Accordingly, cigarette smoke exposed (CSE) and air-exposed C57BL/6J mice were treated f...

  15. Transcriptional analysis of oligosaccharide utilization by Bifidobacterium lactis Bl-04

    OpenAIRE

    Andersen, Joakim Mark; Barrangou, Rodolphe; Abou Hachem, Maher; Lahtinen, Sampo J.; Goh, Yong Jun; Svensson, Birte; Klaenhammer, Todd R.

    2013-01-01

    BACKGROUND: Probiotic bifidobacteria in combination with prebiotic carbohydrates have documented positive effects on human health regarding gastrointestinal disorders and improved immunity, however the selective routes of uptake remain unknown for most candidate prebiotics. The differential transcriptomes of Bifidobacterium animalis subsp. lactis Bl-04, induced by 11 potential prebiotic oligosaccharides were analyzed to identify the genetic loci involved in the uptake and catabolism of α- and...

  16. Nuclear Energy General Objectives

    International Nuclear Information System (INIS)

    One of the IAEA's statutory objectives is to 'seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world'. One way it achieves this objective is to issue publications in various series. Two of these series are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III, paragraph A.6, of the IAEA Statute, the IAEA safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are primarily written in a regulatory style, and are binding on the IAEA for its own activities. The principal users are Member State regulatory bodies and other national authorities. The IAEA Nuclear Energy Series consists of reports designed to encourage and assist research on, and development and practical application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia and politicians, among others. The information is presented in guides, reports on the status of technology and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The series complements the IAEA's safety standards, and provides detailed guidance, experience, good practices and examples on the five areas covered in the IAEA Nuclear Energy Series. The Nuclear Energy Basic Principles is the highest level publication in the IAEA Nuclear Energy Series and describes the rationale and vision for the peaceful uses of nuclear energy. It presents eight Basic Principles on which nuclear energy systems should be based to fulfil nuclear energy's potential to help meet growing global energy needs. The Nuclear Energy Series Objectives are the second level publications. They describe what needs to be

  17. Expression of Duck Interferon Alpha in BL21(DE3)plysS

    Institute of Scientific and Technical Information of China (English)

    REN Gui-ping; QU Juan-juan; PEI Fu-cheng; LI Jing-peng; LIU Xiang-yu; LI Lu; WANG Jun-wei

    2005-01-01

    To obtain the protein of duck interferon alpha and study its biological activities, the prokaryotic ex-pression vector of DuIFN-α was constructed and expressed in BL21 (DE3) plysS. Using PCR technique, the proteingene of DuIFN-α was cloned from pMD-18-duIFN-α recombinant. The gene was then inserted to pGEM-T vectorand identified by restriction endonuclease analysis and sequencing. DuIFN-α was ligated with the prokaryotic expres-sion vector of pET30 a, then transformed into BL21 (DE3) plysS. The best inducing time and IPTG concentration for the expression of this recombinant protein was tested through the expression of the positive recombinant with differ-ent time span and different IPTG concentration. Lots of the protein of DuIFN-α were expressed in BL21 (DE3)plysS with 1 mmol·L-1 IPTG for 4 hours and its molecular weight for 34 000.

  18. Why are some BL Lacs detected by \\fermi, but others not ?

    CERN Document Server

    Wu, Zhongzu; Gu, Minfeng; Chen, Liang

    2014-01-01

    By cross-correlating an archival sample of 170 BL Lacs with 2 year \\fermilat AGN sample, we have compiled a sample of 100 BL Lacs with \\fermi detection (FBLs), and a sample of 70 non-\\fermi BL Lacs (NFBLs). We compared various parameters of FBLs with those of NFBLs, including the redshift, the low frequency radio luminosity at 408 MHz ($L_{\\rm 408MHz}$), the absolute magnitude of host galaxies ($M_{\\rm host}$), the polarization fraction from NVSS survey ($P_{\\rm NVSS}$), the observed arcsecond scale radio core flux at 5 GHz ($F_{\\rm core}$) and jet Doppler factor; all the parameters are directly \\textbf{measured} or derived from available data from literatures. We found that the Doppler factor is on average larger in FBLs than in NFBLs, and the $Fermi~ \\gamma$-ray detection rate is higher in sources with higher Doppler factor. In contrast, there are no significant differences in terms of the intrinsic parameters of redshift, $ L_{\\rm 408MHz}$, $ M_{\\rm host}$ and $ P_{\\rm NVSS}$. FBLs seem to have a higher pr...

  19. Minimal Flavor Violation in the Minimal $U(1)_{B-L}$ Model and Resonant Leptogenesis

    CERN Document Server

    Okada, Nobuchika; Yamada, Toshifumi

    2012-01-01

    We investigate the resonant leptogenesis scenario in the minimally $U(1)_{B-L}$ extended standard model with minimal flavor violation. In our model, the $U(1)_{B-L}$ gauge symmetry is broken at the TeV scale and standard model singlet neutrinos gain Majorana masses of order TeV. In addition, we introduce a flavor symmetry on the singlet neutrinos at a scale higher than TeV. The flavor symmetry is explicitly broken by the neutrino Dirac Yukawa coupling, which induces splittings in the singlet neutrino Majorana masses at lower scales through renormalization group evolutions. We call this setup "minimal flavor violation". The mass-splittings are proportional to the tiny Dirac Yukawa coupling, and hence they automatically enhance the CP asymmetry parameter necessary for the resonant leptogenesis mechanism. In this paper, we calculate the baryon number yield by solving the Boltzmann equations, including the effects of $U(1)_{B-L}$ gauge boson that also has TeV scale mass and causes washing-out of the singlet neutr...

  20. Surface and interface analysis of nanomaterials at microfocus beamline (BL-16) of Indus-2

    Science.gov (United States)

    Das, Gangadhar; Khooha, Ajay; Kane, S. R.; Singh, A. K.; Tiwari, M. K.

    2016-05-01

    Analysis of chemical nature and electronic structure at the interface of a thin film medium is important in many technological applications as well as to understand overall efficiency of a thin film device. Synchrotron radiation based x-ray spectroscopy is a promising technique to study interface nature of the nanomaterials with atomic resolutions. A combined x-ray reflectivity and grazing incidence x-ray fluorescence measurement facility has been recently constructed at the BL-16 microfocus beamline of Indus-2 synchrotron facility to accomplish surface-interface microstructural characterization of thin layered materials. It is also possible to analyze contaminates or adsorbed ad-atoms on the surface of the thin nanostructure materials. The BL-16 beamline also provides an attractive platform to perform a variety of analytical research activities especially in the field of micro x-ray fluorescence and ultra-trace elements analysis using Synchrotron radiation. We describe various salient features of the BL-16 reflectometer experimental station and the detailed description of its capabilities through the measured results, obtained for various thin layered nanomaterials.

  1. Identification of mutations through dominant screening for obesity using C57BL/6 substrains.

    Science.gov (United States)

    Hossain, Mohammad Sarowar; Asano, Fuyuki; Fujiyama, Tomoyuki; Miyoshi, Chika; Sato, Makito; Ikkyu, Aya; Kanno, Satomi; Hotta, Noriko; Kakizaki, Miyo; Honda, Takato; Kim, Staci J; Komiya, Haruna; Miura, Ikuo; Suzuki, Tomohiro; Kobayashi, Kimio; Kaneda, Hideki; Kumar, Vivek; Takahashi, Joseph S; Wakana, Shigeharu; Funato, Hiromasa; Yanagisawa, Masashi

    2016-01-01

    The discovery of leptin substantiated the usefulness of a forward genetic approach in elucidating the molecular network regulating energy metabolism. However, no successful dominant screening for obesity has been reported, which may be due to the influence of quantitative trait loci between the screening and counter strains and the low fertility of obese mice. Here, we performed a dominant screening for obesity using C57BL/6 substrains, C57BL/6J and C57BL/6N, with the routine use of in vitro fertilization. The screening of more than 5000 mutagenized mice established two obese pedigrees in which single nucleotide substitutions in Mc4r and Sim1 genes were identified through whole-exome sequencing. The mutation in the Mc4r gene produces a premature stop codon, and the mutant SIM1 protein lacks transcriptional activity, showing that the haploinsufficiency of SIM1 and MC4R results in obesity. We further examined the hypothalamic neuropeptide expressions in the mutant pedigrees and mice with diet-induced obesity, which showed that each obesity mouse model has distinct neuropeptide expression profiles. This forward genetic screening scheme is useful and applicable to any research field in which mouse models work. PMID:27585985

  2. The stellar content of low redshift BL Lac host galaxies from multicolour imaging

    Directory of Open Access Journals (Sweden)

    T. Hyvönen

    2008-01-01

    Full Text Available Presentamos imágenes en las bandas UBV de 18 objetos BL Lac de bajo corrimiento al rojo (z ≤ 0.3. Estos datos se usan para investigar los colores rojo-azul-infrarrojo y gradientes de color de galaxias huésped. La distribución del color integrado azul/cercano-infrarrojo y el gradiente de color de las galaxias huésped de objetos BL Lac es más amplia que la que tienen las elípticas no-activas, y la mayoría de los objetos BL Lac tienen galaxias huésped más azules y gradientes de color más empinados que los de las elípticas no-activas. Los colores azules parecen ser causados por una componente de la población estelar joven, e indican una conexión entre la formación estelar causada por un evento de interacción/fusión, y el encendido de la actividad nuclear. Este resultado es apoyado por los modelos de población estelar, que indican que existe una población estelar joven/intermedia en la mayoría de los objetos de la muestra.

  3. Accidental Dark Matter: Case in the Scale Invariant Local $B-L$ Model

    CERN Document Server

    Guo, Jun; Ko, P; Orikasa, Yuta

    2015-01-01

    We explore the idea of accidental dark matter (aDM) stability in the scale invariant local $U(1)_{B-L}$ model, which is a theory for neutrino and at the same time radiatively breaks scale invariance via quantum mechanical dynamics in the $U(1)_{B-L}$ sector. A real singlet scalar can be accidental DM with an accidental $Z_2$, by virtue of both extended symmetries. A $U(1)_{B-L}$ charged complex scalar can also be a viable accidental DM due to an accidental (or remanent) $Z_3$. They can reproduce correct relic density via the annihilations through the conventional Higgs portal or dark Higgs portal. The dark Higgs portal scenario is in tension with the LHC bound on $Z_{B-L}$, and only heavy DM of a few TeVs can have correct relic density. In particular, DM may trigger spontaneous breaking of scale Invariance (SISB). The situation is relaxed significantly in the $Z_3$ case due to the effective semi-annihilation mode and then light DM can be accommodated easily. In addition, the $Z_3$ model can accommodate the Ge...

  4. The mass spectra, hierarchy and cosmology of B-L MSSM heterotic compactifications

    International Nuclear Information System (INIS)

    The matter spectrum of the MSSM, including three right-handed neutrino supermultiplets and one pair of Higgs-Higgs conjugate superfields, can be obtained by compactifying the E8 x E8 heterotic string and M-theory on Calabi-Yau manifolds with specific SU(4) vector bundles. These theories have the standard model gauge group augmented by an additional gauged U(1)B-L. Their minimal content requires that the B-L gauge symmetry be spontaneously broken by a vacuum expectation value of at least one right-handed neutrino. In previous papers, we presented the results of a quasi-analytic renormalization group analysis showing that B-L gauge symmetry is indeed radiatively broken with an appropriate B-L/electroweak hierarchy. In this paper, we extend these results by 1) enlarging the initial parameter space and 2) explicitly calculating all renormalization group equations numerically. The regions of the initial parameter space leading to realistic vacua are presented and the B-L/electroweak hierarchy computed over these regimes. At representative points, the mass spectrum for all particles and Higgs fields is calculated and shown to be consistent with present experimental bounds. Some fundamental phenomenological signatures of a non-zero right-handed neutrino expectation value are discussed, particularly the cosmology and proton lifetime arising from induced lepton and baryon number violating interactions

  5. Pure Gravity Mediation and Spontaneous B-L Breaking from Strong Dynamics

    CERN Document Server

    Babu, Kaladi S; Yanagida, Tsutomu T

    2015-01-01

    In pure gravity mediation (PGM), the most minimal scheme for the mediation of supersymmetry (SUSY) breaking to the visible sector, soft masses for the standard model gauginos are generated at one loop rather than via direct couplings to the SUSY-breaking field. In any concrete implementation of PGM, the SUSY-breaking field is therefore required to carry nonzero charge under some global or local symmetry. As we point out in this note, a prime candidate for such a symmetry might be B-L, the Abelian gauge symmetry associated with the difference between baryon number B and lepton number L. The F-term of the SUSY-breaking field then not only breaks SUSY, but also B-L, which relates the respective spontaneous breaking of SUSY and B-L at a fundamental level. As a particularly interesting consequence, we find that the heavy Majorana neutrino mass scale ends up being tied to the gravitino mass, Lambda_N ~ m_3/2. Assuming nonthermal leptogenesis to be responsible for the generation of the baryon asymmetry of the univer...

  6. Extract of Kuding tea prevents high-fat diet-induced metabolic disorders in C57BL/6 mice via liver X receptor (LXR β antagonism.

    Directory of Open Access Journals (Sweden)

    Shengjie Fan

    Full Text Available OBJECTIVE: To investigate the effects of ilex kudingcha C. J. Tseng (kuding tea, a traditional beverage in China, on the metabolic disorders in C57BL/6 mice induced by high-fat diets. DESIGN: For the preventive experiment, the female C57BL/6 mice were fed with a standard diet (Chow, high-fat diet (HF, and high-fat diet mixed with 0.05% ethanol extract of kuding tea (EK for 5 weeks. For the therapeutic experiment, the C57BL/6 mice were fed high-fat diet for 3 months, and then mice were split and EK was given with oral gavages for 2 weeks at 50 mg/day/kg. Body weight and daily food intake amounts were measured. At the end of treatment, the adipocyte images were assayed with a scanning electron microscope, and the fasting blood glucose, glucose tolerance test, serum lipid profile and lipids in the livers were analyzed. A reporter gene assay system was used to test the whether EK could act on nuclear receptor transcription factors, and the gene expression analysis was performed with a quantitative PCR assay. RESULTS: In the preventive treatment, EK blocked the body weight gain, reduced the size of the adipocytes, lowered serum triglyceride, cholesterol, LDL-cholesterol, fasting blood glucose levels and glucose tolerance in high-fat diet-fed C57BL/6 mice. In the therapeutic treatment, EK reduced the size of the white adipocytes, serum TG and fasting blood glucose levels in obese mice. With the reporter assay, EK inhibited LXRβ transactivity and mRNA expression of LXRβ target genes. CONCLUSION: We observed that EK has both preventive and therapeutic roles in metabolic disorders in mice induced with high-fat diets. The effects appear to be mediated through the antagonism of LXRβ transactivity. Our data indicate that kuding tea is a useful dietary therapy and a potential source for the development of novel anti-obesity and lipid lowering drugs.

  7. 近交系C57BL/6J小鼠的脱毛特征%The features of hair loss in the inbred strain of C57BL/6J

    Institute of Scientific and Technical Information of China (English)

    黄月玲; 侯敏; 戴丽军; 谭小军; 任韵; 叶炳飞; 朴金松; 高蔚樱; 劳淑贞; 周敏仪

    2012-01-01

    目的 了解近交系C57BL/6J小鼠脱毛的性质和脱毛的特征.方法 在各代鼠详细观察记录脱毛出现的时间、状况和缓解情况;利用对照组2对来自不同父母鼠的F1雌雄鼠进行交配实验和回盒饲养实验,观察脱毛和脱毛缓解的特征,在F2小鼠观察脱毛特征的遗传性,对脱毛区域皮肤进行病理分析.结果 脱毛(头、颈或背部)多出现在3~6只同养的雌性鼠中(对照组32.4%,实验组16.3%),脱毛-新毛生长的过程交替进行,交配有缓解脱毛的作用并能维持新毛的生长状态,脱毛的特征可以遗传.皮肤病理显示皮肤各层结构、毛囊和毛囊球上皮无明显病理性改变.结论 脱毛可能是本品系在特定饲养条件下适应环境压力失败及缺乏生理活动的一种表现,具有经过良性、可缓解、特征可遗传等特点.%Objective To characterize the nature and features of hair loss in the inbred strain C57BL/6J. Methods The development, manifestations and improving conditions of hair loss were closely observed and recorded in each generation. Two pairs of F1 female and male offspring that came from two different parental mice were used to mate in order to determine if hair loss would improve and at the same time to confirm if the features of hair loss would pass onto the F2 generation. After mating, the females continued to live with their corresponding sisters in the same cage so as to observe if hair loss would re-occur. The skin with hair loss was processed for pathologic examination. Results Hair loss most frequently developed spontaneously on the head, neck and dorsal areas in female mice that 3 to 6 lived together in the same cage (control group: 32.4%, experimental group: 16.3%). The process of hair loss-hair growth alternated constantly. Hair loss was significantly alleviated by mating, and mating could sustain the growth of hairs that re-grown after loss. The features of hair loss could pass onto the next

  8. On Coordinating Collaborative Objects

    Directory of Open Access Journals (Sweden)

    Abdessamad Imine

    2010-07-01

    Full Text Available A collaborative object represents a data type (such as a text document designed to be shared by a group of dispersed users. The Operational Transformation (OT is a coordination approach used for supporting optimistic replication for these objects. It allows the users to concurrently update the shared data and exchange their updates in any order since the convergence of all replicas, i.e. the fact that all users view the same data, is ensured in all cases. However, designing algorithms for achieving convergence with the OT approach is a critical and challenging issue. In this paper, we propose a formal compositional method for specifying complex collaborative objects. The most important feature of our method is that designing an OT algorithm for the composed collaborative object can be done by reusing the OT algorithms of component collaborative objects. By using our method, we can start from correct small collaborative objects which are relatively easy to handle and incrementally combine them to build more complex collaborative objects.

  9. Evaluation of Beneficial Metabolic Effects of Berries in High-Fat Fed C57BL/6J Mice

    Directory of Open Access Journals (Sweden)

    Lovisa Heyman

    2014-01-01

    Full Text Available Objective. The aim of the study was to screen eight species of berries for their ability to prevent obesity and metabolic abnormalities associated with type 2 diabetes. Methods. C57BL/6J mice were assigned the following diets for 13 weeks: low-fat diet, high-fat diet or high-fat diet supplemented (20% with lingonberry, blackcurrant, bilberry, raspberry, açai, crowberry, prune or blackberry. Results. The groups receiving a high-fat diet supplemented with lingonberries, blackcurrants, raspberries or bilberries gained less weight and had lower fasting insulin levels than the control group receiving high-fat diet without berries. Lingonberries, and also blackcurrants and bilberries, significantly decreased body fat content, hepatic lipid accumulation, and plasma levels of the inflammatory marker PAI-1, as well as mediated positive effects on glucose homeostasis. The group receiving açai displayed increased weight gain and developed large, steatotic livers. Quercetin glycosides were detected in the lingonberry and the blackcurrant diets. Conclusion. Lingonberries were shown to fully or partially prevent the detrimental metabolic effects induced by high-fat diet. Blackcurrants and bilberries had similar properties, but to a lower degree. We propose that the beneficial metabolic effects of lingonberries could be useful in preventing obesity and related disorders.

  10. Mono-jet, -photon and -Z Signals of a Supersymmetric (B-L) model at the Large Hadron Collider

    CERN Document Server

    Abdallah, W; Khalil, S; Moretti, S

    2015-01-01

    Search for invisible final states produced at the Large Hadron Collider (LHC) by new physics scenarios are normally carried out resorting to a variety of probes emerging from the initial state, in the form of single-jet, -photon and -$Z$ boson signatures. These are particularly effective for models of Supersymmetry (SUSY) in presence of $R$-parity conservation, owing to the presence in their spectra of a stable neutralino as dark matter candidate. We assume here as theoretical framework Supersymmetric ($B-L$) extension of the Standard Model (BLSSM), wherein a mediator for invisible decays can be $Z'$ boson. The peculiarity of the signal is thus that the final state objects carry a very large (transverse) missing energy, since the $Z'$ is naturally massive and constrained by direct searches and electro-weak precision tests to be at least in TeV scale region. Under these circumstances the efficiency in accessing the invisible final state and rejecting the standard model background is very high. This somehow com...

  11. Functional Object Analysis

    DEFF Research Database (Denmark)

    Raket, Lars Lau

    We propose a direction it the field of statistics which we will call functional object analysis. This subfields considers the analysis of functional objects defined on continuous domains. In this setting we will focus on model-based statistics, with a particularly emphasis on mixed......-effect formulations, where the observed functional signal is assumed to consist of both fixed and random functional effects. This thesis takes the initial steps toward the development of likelihood-based methodology for functional objects. We first consider analysis of functional data defined on high...

  12. The field high-amplitude SX Phe variable BL Cam: results from a multisite photometric campaign. II. Evidence of a binary - possibly triple - system

    CERN Document Server

    Fauvaud, S; Ribas, I; Rodríguez, E; Lampens, P; Klingenberg, G; Farrell, J A; Fumagalli, F; Simonetti, J H; Wolf, M; Santacana, G; Zhou, A -Y; Michel, R; Fox-Machado, L; Alvarez, M; Nava-Vega, A; López-González, M J; Casanova, V M; Aceituno, F J; Scheggia, I; Rives, J -J; Hintz, E G; Van Cauteren, P; Helvaci, M; Yesilyaprak, C; Graham, K A; Král, L; Kocián, R; Kučáková, H; Fauvaud, M; Granslo, B H; Michelet, J; Nicholson, M P; Vugnon, J -M; Kotková, L; Truparová, K; Ulusoy, C; Yasarsoy, B; Avdibegovic, A; Blauzek, M; Kliner, J; Zasche, P; Bartošíková, S; Vilášek, M; Trondal, O; Abbeel, F Van Den; Behrend, R; Wücher, H

    2010-01-01

    Short-period high-amplitude pulsating stars of Population I ($\\delta$ Sct stars) and II (SX Phe variables) exist in the lower part of the classical (Cepheid) instability strip. Most of them have very simple pulsational behaviours, only one or two radial modes being excited. Nevertheless, BL Cam is a unique object among them, being an extreme metal-deficient field high-amplitude SX Phe variable with a large number of frequencies. Based on a frequency analysis, a pulsational interpretation was previously given. aims heading (mandatory) We attempt to interpret the long-term behaviour of the residuals that were not taken into account in the previous Observed-Calculated (O-C) short-term analyses. methods heading (mandatory) An investigation of the O-C times has been carried out, using a data set based on the previous published times of light maxima, largely enriched by those obtained during an intensive multisite photometric campaign of BL Cam lasting several months. results heading (mandatory) In addition to a po...

  13. Pre-clinical evolutionary study of Clerodendrum phlomidis as an anti-obesity agent against high fat diet induced C57BL/6J mice

    Institute of Scientific and Technical Information of China (English)

    Vijay R Chidrawar; Krishnakant N Patel; Havagiray R Chitme; Shruti S Shiromwar

    2012-01-01

    Objective: Anti-obesity activity of alcoholic and methanolic extracts of roots of Clerodendrumphlomidis was evaluated against high fat diet (HFD) induced obesity in C57BL/6J female mice. Methods: Obesity was induced by feeding high fat diet for 13 weeks to C57BL/6J female mice and one group was kept on normal chow diet in order to evaluate the effect of Clerodendrumphlomidis on food intake, body weight changes, digestive enzyme activity, lipid metabolism, theromogenesis, adiposities diameter and histology of fat pad. Results: Among these two extracts methanolic extract of Clerodendrum phlomidis (MECP) have shown strong anti-obesity effect compare to alcoholic extract of Clerodendrum phlomidis (AECP). LD50 value was found to be more than 2000 mg/kg. Conclusions: MECP have shown more promising effects than AECP may be because of its multiple mechanisms. Anti-obesity activity produced by MECP is because of inhibition of pancreatic lipase activity which delays the intestinal absorption of dietary fat. Inhibition of pancreatic lipase activity was confirmed by in-vitro studies. MECP also containsβ-sitosterol in abundant amount which was confirmed by HPTLC analysis. Moreover flavonoid content in the plant has anorexic property. By this study we concluded that MECP is beneficial for the suppression of obesity and associated complications like T2DM.

  14. Spatial Objects Monitoring

    Directory of Open Access Journals (Sweden)

    Maiya V. Maximovа

    2012-12-01

    Full Text Available The paper studies the spatial objects monitoring, classifies its types, differentiates local, regional, national and global, geodetic and geoinformation monitoring, discloses basic principles of GIS monitoring.

  15. Piles of objects

    KAUST Repository

    Hsu, Shu-Wei

    2010-01-01

    We present a method for directly modeling piles of objects in multi-body simulations. Piles of objects represent some of the more interesting, but also most time-consuming portion of simulation. We propose a method for reducing computation in many of these situations by explicitly modeling the piles that the objects may form into. By modeling pile behavior rather than the behavior of all individual objects, we can achieve realistic results in less time, and without directly modeling the frictional component that leads to desired pile shapes. Our method is simple to implement and can be easily integrated with existing rigid body simulations. We observe notable speedups in several rigid body examples, and generate a wider variety of piled structures than possible with strict impulse-based simulation. © 2010 ACM.

  16. Safety objectives for 2014

    CERN Multimedia

    HSE Unit

    2014-01-01

    This is the third year in which the CERN Management has presented annual safety objectives for the Organization, the “HSE Objectives”.   The HSE objectives for 2014, which were announced by the Director-General at his traditional New Year’s address to the staff and were presented at the first Enlarged Directorate meeting of the year, have been drawn up and agreed in close collaboration between the DSOs, the HSE Unit and the DG himself. From safety in the workplace to radiation and environmental protection, the document emphasises that “Safety is a priority for CERN” and that safety policy is a key element in how the Organization is run. And, like all policies, it generates objectives that “serve as a general framework for action”. The HSE objectives are broken down into the following fields: occupational health and safety on sites and in the workplace, radiation protection, radiation safety, environmental protection, emerge...

  17. Pedagogically Sound Learning Objects

    OpenAIRE

    Churchill, D.

    2005-01-01

    This seminar is co-organized by CITE & the Faculty of Education Learning objects recently received considerable attention in education and training community. The fundamental idea behind learning objects is that instead of traditional courseware packages, curriculum content can be broken down in small components. The components can be tagged with metadata descriptors and deposited in digital libraries for reuse. So called learning management standards have set essential technical requirem...

  18. Uniqueness of Intentional Objects

    Czech Academy of Sciences Publication Activity Database

    Hvorecký, Juraj

    Bratislava : Filozofický ústav SAV, 2006, s. 179-188 ISBN 80-967225-6-5. [Sémantika verzus pragmatika - kde sú hranice?. Stará Lesná ve Vysokých Tatrách (SK), 12.09.2005-14.09.2005] Institutional research plan: CEZ:AV0Z90090514 Keywords : intentional object * emotions * formal object Subject RIV: AA - Philosophy ; Religion

  19. Protected Objects in Java

    DEFF Research Database (Denmark)

    Løvengreen, Hans Henrik; Schwarzer, Jens Christian

    1998-01-01

    We present an implementation of Ada 95's notion of protected objects in Java. The implementation comprises a class library supporting entry queues and a (pre-) compiler translating slightly decorated Java classes to pure Java classes utilizing the library.......We present an implementation of Ada 95's notion of protected objects in Java. The implementation comprises a class library supporting entry queues and a (pre-) compiler translating slightly decorated Java classes to pure Java classes utilizing the library....

  20. Android object recognition framework

    OpenAIRE

    Karlsen, Mats-Gøran

    2012-01-01

    This thesis is a continuation of the author’s specialization project where the ultimate goal is to build an object recognition framework suitable for mobile devices in real world environments, where control over parameters such as illumination, distance, noise and availability of consistent network architectures are limited. Based on shortcomings related to object recognition performance and architectural issues the author’s goal was to increase the flexibility, usability and perfor...

  1. Observation and Quantum Objectivity

    OpenAIRE

    Healey, Richard

    2012-01-01

    The paradox of Wigner's friend challenges the objectivity of description in quantum theory. A pragmatist interpretation can meet this challenge by judicious appeal to decoherence. On this interpretation, quantum theory provides situated agents with resources for predicting and explaining what happens in the physical world---not conscious observations of it. Even in Wigner's friend scenarios, differently situated agents agree on the objective content of statements about the values of physical ...

  2. Tracking objects, Tracking agents

    OpenAIRE

    Bullot, Nicolas J.; Rysiew, Patrick

    2005-01-01

    Animals and humans have to keep track of individuals in their environment, both in perception (sensorimotor tracking) and in cognition (e.g., spatio-temporal localization and linguistic reference via memory, communication and reasoning). Items that are typical targets for tracking are things such as stationary physical objects (e.g., rocks, plants, trees, buildings, or attached artifacts), moving physical objects (e.g., animals, certain artifacts) and human beings. All such items are located ...

  3. Disruptions and Disturbance as Challenges in a Blended Learning (BL) Environment and the Role of Embodied Habit Orientation

    DEFF Research Database (Denmark)

    Dau, Susanne; Ryberg, Thomas

    2014-01-01

    In this paper we analyse two cases where BL courses have been run since the summer 2012 (Teachers´ and the radiography educational programmes at University College North in Denmark (UCN). In this study it was clear that the majority of students preferred face-to-face instructions and interaction...... over the implemented BL approach and they felt more disrupted and disturbed when required to work more online and from home. In the paper we therefore discuss how disruptions and disturbances have an influence on students’ study and learning activities in a BL environment. We argue how disturbances are...... and discuss how students’ orientation in different learning environments influence their navigation, and how disruptions and disturbances affect their orientation. The findings illustrate and discuss students’ challenges of adapting to the BL approach and how students’ prior experiences and habits...

  4. A high density physical map of chromosome 1BL supports evolutionary studies, map-based cloning and sequencing in wheat

    Czech Academy of Sciences Publication Activity Database

    Philippe, R.; Paux, E.; Bertin, I.; Sourdille, P.; Choulet, F.; Laugier, Ch.; Šimková, Hana; Šafář, Jan; Bellec, A.; Vautrin, S.; Frenkel, Z.; Cattonaro, F.; Magni, F.; Scalabrin, S.; Martis, M.M.; Mayer, K. F. X.; Korol, A.; Berges, H.; Doležel, Jaroslav; Feuillet, C.

    2013-01-01

    Roč. 14, č. 6 (2013). ISSN 1465-6906 Institutional research plan: CEZ:AV0Z50380511 Keywords : chromosome 1BL * evolution * gene space Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.465, year: 2013

  5. Recent observations of 1ES2344+514 using the Whipple gamma-ray telescope

    International Nuclear Information System (INIS)

    BL Lacertae objects are a class of AGN which are believed to be highly beamed. Very high energy gamma-rays emitted from such objects provide important information that improves our understanding of this class of objects. Only two AGNs, Mrk 421 and Mrk 501, are well established TeV emitters in the northern hemisphere. The Whipple collaboration previously reported a weak signal from the BL Lac object 1ES 2344+514. This object has been extensively monitored with atmospheric Cherenkov experiments from 1997 to 1999 with no other reported detection. The results of observations in 1999-2001 of 1ES 2344+514 taken with the new Whipple 490 pixel camera are presented. These observations resulted in a detection at the 3 σ level

  6. Crystal Structure of Crataeva tapia Bark Protein (CrataBL and Its Effect in Human Prostate Cancer Cell Lines.

    Directory of Open Access Journals (Sweden)

    Rodrigo da Silva Ferreira

    Full Text Available A protein isolated from the bark of Crataeva tapia (CrataBL is both a Kunitz-type plant protease inhibitor and a lectin. We have determined the amino acid sequence and three-dimensional structure of CrataBL, as well as characterized its selected biochemical and biological properties. We found two different isoforms of CrataBL isolated from the original source, differing in positions 31 (Pro/Leu; 92 (Ser/Leu; 93 (Ile/Thr; 95 (Arg/Gly and 97 (Leu/Ser. CrataBL showed relatively weak inhibitory activity against trypsin (Kiapp = 43 µM and was more potent against Factor Xa (Kiapp = 8.6 µM, but was not active against a number of other proteases. We have confirmed that CrataBL contains two glycosylation sites and forms a dimer at high concentration. The high-resolution crystal structures of two different crystal forms of isoform II verified the β-trefoil fold of CrataBL and have shown the presence of dimers consisting of two almost identical molecules making extensive contacts (∼645 Å(2. The structure differs from those of the most closely related proteins by the lack of the N-terminal β-hairpin. In experiments aimed at investigating the biological properties of CrataBL, we have shown that addition of 40 µM of the protein for 48 h caused maximum growth inhibition in MTT assay (47% of DU145 cells and 43% of PC3 cells. The apoptosis of DU145 and PC3 cell lines was confirmed by flow cytometry using Annexin V/FITC and propidium iodide staining. Treatment with CrataBL resulted in the release of mitochondrial cytochrome c and in the activation of caspase-3 in DU145 and PC3 cells.

  7. Uji Sitotoksik Ekstrak Metanol Kulit Kayu Tumbuhan Cep-Cepen (Castanopsis Costata Bl) Dengan Metode Brine Shrimp Lethality Assays

    OpenAIRE

    Kelana, Tata Bintara

    2010-01-01

    Telah dilakukan penelitian terhadap ekstrak kulit kayu tumbuhan Cep-cepen (Castanopsis Costata BL) yang pemeriksaannya dilaksanakan dengan cara 100 g kulit batang tumbuhan Cep-cepen (Castanopsis Costata BL) yang dimaserasi dengan methanol sebanyak 1200 ml dan diulang 5 kali maserasi dengan waktu maserasi 5 hari. Maserat dipekatkan dengan vacum dan diperoleh berat ekstrak pekat metanol = 5,7 g. Uji pendahuluan fitokimia memperlihatkan adanya senyawa kelompok flavonoida. Uji toksisitas ekst...

  8. Objects of consciousness

    Directory of Open Access Journals (Sweden)

    Donald David Hoffman

    2014-06-01

    Full Text Available 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 preexist-ing physical truths: Certain interpretations of quantum theory deny that dynamical properties of physical objects have defi-nite values when unobserved. In some of these interpretations the observer is fundamental, and wave functions are com-pendia 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.

  9. Objects of consciousness.

    Science.gov (United States)

    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

  10. 小麦1BL/1RS和7DL·7Ag易位对小麦主要农艺性状的遗传效应%Genetic Effects of Chromosome Translocations 1BL/1RS and 7DL · 7Ag on the Main Agronomic Traits of Common Wheat

    Institute of Scientific and Technical Information of China (English)

    胡阳杰; 田芳慧; 宋全昊; 李法计; 孙道杰

    2012-01-01

    为了解染色体易位对小麦农艺性状的影响,以豫农982(1BL/1RS易位系)和wheatear(7DL.7Ag易位系)杂交后代的900个F2群体及其F2∶3家系为实验材料,对F2群体进行1BL/1RS易位和7DL.7Ag易位类型的分子检测,并对F2群体及F2∶3家系的主要农艺性状进行田间调查(F2群体的农艺性状仅作参考,重点分析F2∶3家系的农艺性状)。结果表明,(1)STS标记Lr19130与SSR引物Xgwm428联合使用可作为共显性标记鉴定纯合与杂合的7DL.7Ag易位,完善了7DL.7Ag易位的分子检测方法;(2)1BL/1RS易位可显著降低株高,提高穗粒数与小穗数;(3)7DL.7Ag易位在籽粒千粒重和饱满度上有显著的正向作用,但7DL.7Ag易位的穗粒数显著低于非7DL.7Ag易位,且有延迟小麦成熟和增加株高的趋势;(4)1BL/1RS和7DL.7Ag双重易位可同时提升小穗数和千粒重,但穗粒数减少。%The 1BL/1RS translocation and 7DL ·7Ag translocation have been widely used by wheat breeders to enhance agronomic performance and disease resistance. The objective of this study was to analyze the genetic effects of 1BL/1RS and 7DL ·7Ag chromosome translocations on the main agro- nomic traits of wheat. A total of 900 F2 population and F2.3 family derived from the cross Yunong 982 (1BL/1RS translocation) / wheatear (TDL · 7Ag translocation) were planted in Yangling of Shaanxi Province during 2009--2011. The chromosome translocation types of F2 population were identified u- sing SSR and STS. In addition, a total of 15 traits of the two parents, F2 population and F2. a family, such as plant height, spike length, grain number per spike, thousand-grain weight, grain weight per spike and days from emergeto maturity, were investigated (this study took the agronomic traits of F2 population as a reference, the main agronomic traits of F2.3 family were the key point of this study). The F-test and multiple comparisons of the agronomic traits of no

  11. Radioactive Waste Management Objectives

    International Nuclear Information System (INIS)

    One of the IAEA's statutory objectives is to 'seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world'. One way it achieves this objective is to issue publications in various series. Two of these series are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III, paragraph A.6, of the IAEA Statute, the IAEA safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are primarily written in a regulatory style, and are binding on the IAEA for its own activities. The principal users are Member State regulatory bodies and other national authorities. The IAEA Nuclear Energy Series consists of reports designed to encourage and assist research on, and development and practical application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia and politicians, among others. The information is presented in guides, reports on the status of technology and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The series complements the IAEA's safety standards, and provides detailed guidance, experience, good practices and examples on the five areas covered in the IAEA Nuclear Energy Series. The Nuclear Energy Basic Principles is the highest level publication in the IAEA Nuclear Energy Series and describes the rationale and vision for the peaceful uses of nuclear energy. It presents eight Basic Principles on which nuclear energy systems should be based to fulfil nuclear energy's potential to help meet growing global energy needs. The Nuclear Energy Series Objectives are the second level publications. They describe what needs to be

  12. Near-infrared micro-variability of radio-loud quasars

    OpenAIRE

    Whiting, Matthew; Oshlack, Alicia; Webster, Rachel

    2001-01-01

    We observed three AGN from the Parkes Half-Jansky Flat-spectrum Sample at near-infrared (NIR) wavelengths to search for micro-variability. In one source, the blue quasar PKS 2243-123, good evidence for NIR micro-variability was found. In the other two sources, PKS 2240-260 and PKS 2233-148, both BL Lacertae objects, no such evidence of variability was detected. We discuss the implications of these observations for the various mechanisms that have been proposed for micro-variability.

  13. VHE gamma-ray observations of Markarian 501

    OpenAIRE

    Whipple Collaboration; Breslin, A. C.; Bond, I. H.; Bradbury, S. M.; J. H. Buckley(Department of Physics, Washington University, St. Louis, USA); Burdett, A. M.; Carson, M. J.; Carter-Lewis, D. A.; Catanese, M.; Cawley, M. F.; Dunlea, S.; D'Vali, M.; Fegan, D. J.; Fegan, S. J.; Finley, J. P.

    1999-01-01

    Markarian 501, a nearby (z=0.033) X-ray selected BL Lacertae object, is a well established source of Very High Energy (VHE, E>=300 GeV) gamma rays. Dramatic variability in its gamma-ray emission on time-scales from years to as short as two hours has been detected. Multiwavelength observations have also revealed evidence that the VHE gamma-ray and hard X-ray fluxes may be correlated. Here we present results of observations made with the Whipple Collaboration's 10 m Atmospheric Cerenkov Imaging...

  14. Multiwavelength Observations of a Flare from Markarian 501

    OpenAIRE

    Catanese, M.; Bradbury, S. M.; Breslin, A. C.; J. H. Buckley(Department of Physics, Washington University, St. Louis, USA); Carter-Lewis, D. A.; Cawley, M. F.; Dermer, C. D.; Fegan, D. J.; Finley, J. P.; Gaidos, J. A.; Hillas, A.M.; Johnson, W. N.; Krennrich, F.; Lamb, R. C.; Lessard, R. W.

    1997-01-01

    We present multiwavelength observations of the BL Lacertae object Markarian 501 (Mrk 501) in 1997 between April 8 and April 19. Evidence of correlated variability is seen in very high energy (VHE, E > 350 GeV) gamma-ray observations taken with the Whipple Observatory gamma-ray telescope, data from the Oriented Scintillation Spectrometer Experiment of the Compton Gamma-Ray Observatory, and quicklook results from the All-Sky Monitor of the Rossi X-ray Timing Explorer while the Energetic Gamma-R...

  15. The Flux Variability of Markarian 501 in Very High Energy Gamma Rays

    OpenAIRE

    Quinn, J.; Bond, I. H.; Boyle, P. J.; Bradbury, S. M.; Breslin, A. C.; J. H. Buckley(Department of Physics, Washington University, St. Louis, USA); Burdett, A. M.; Gordo, J. Bussons; Carter-Lewis, D. A.; Catanese, M.; Cawley, M. F.; Fegan, D. J.; Finley, J. P.; Gaidos, J. A.; Hall, T.

    1999-01-01

    The BL Lacertae object Markarian 501 was identified as a source of gamma-ray emission at the Whipple Observatory in March 1995. Here we present a flux variability analysis on several times-scales of the 233 hour data set accumulated over 213 nights (from March 1995 to July 1998) with the Whipple Observatory 10 m atmospheric Cherenkov imaging telescope. In 1995, with the exception of a single night, the flux from Markarian 501 was constant on daily and monthly time-scales and had an average fl...

  16. Discovery of Very High Energy Gamma Rays from 1ES 1440+122

    OpenAIRE

    VERITAS Collaboration; Archambault, S.; Archer, A.; Barnacka, A.; Behera, B.; Beilicke, M.; Benbow, W.; Berger, K; Bird, R.; Boettcher, M.; J. H. Buckley(Department of Physics, Washington University, St. Louis, USA); Bugaev, V.; Cardenzana, J. V; M. Cerruti(Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645, USA); Chen, X.

    2016-01-01

    The BL Lacertae object 1ES 1440+122 was observed in the energy range from 85 GeV to 30 TeV by the VERITAS array of imaging atmospheric Cherenkov telescopes. The observations, taken between 2008 May and 2010 June and totalling 53 hours, resulted in the discovery of $\\gamma$-ray emission from the blazar, which has a redshift $z$=0.163. 1ES 1440+122 is detected at a statistical significance of 5.5 standard deviations above the background with an integral flux of (2.8$\\pm0.7_{\\mathrm{stat}}\\pm0.8...

  17. Beaming Effect in Fermi Blazars

    OpenAIRE

    Fan, J.H.; Yang, J. H.; Zhang, J Y; Hua, T. X.; Liu, Y.; Qin, Y. P.; Huang, Y.

    2012-01-01

    The \\gamma-ray loud blazars (flat spectrum radio quasars--FSRQs and BL Lacertae objects-BLs) are very bright in the \\gamma-ray bands, which is perhaps associated with a beaming effect. Therefore, one can expect that the \\gamma-ray luminosity is correlated with the beaming factor. In this paper, we investigated the relation between the radio Doppler factors and the gamma-ray luminosities. Our analysis suggests that the \\gamma-ray luminosity be strongly correlated with the factor of \\delta_R fo...

  18. Correlation between -Ray and Radio Bands for -Ray Loud Blazars

    Indian Academy of Sciences (India)

    D. X. Wu; J. H. Fan; S. H. Li

    2014-09-01

    The most identified sources observed by Fermi are blazars (Flat Spectrum Radio Quasars (FSRQs) and BL Lacertae objects (BLs). In this paper, we obtained 124 -ray loud blazars with available -ray and radio (core and total) data. It is interesting that the -ray luminosity have a good correlation with the radio luminosity. This phenomenon exists in the core radio luminosity (c) and total radio luminosity (t). The correlation between the -ray and the radio luminosities is still stronger even after we eliminated the redshift effect, which suggests that the -ray radiations in the -ray loud blazars are strongly beamed.

  19. NLO+NLL Collider Bounds, Dirac Fermion and Scalar Dark Matter in the B-L Model

    CERN Document Server

    Klasen, Michael; Queiroz, Farinaldo S

    2016-01-01

    Baryon and lepton numbers being accidental global symmetries of the Standard Model (SM), it is natural to promote them to local symmetries. However, to preserve anomaly freedom, only combinations of B-L are viable. In this spirit, we investigate possible dark matter realizations in the context of the $U(1)_{B-L}$ model: (i) Dirac fermion with unbroken B-L; (ii) Dirac fermion with broken B-L; (iii) scalar dark matter; (iv) two component dark matter. We compute the relic abundance, direct and indirect detection observables and confront them with recent results from Planck, LUX-2016, and Fermi-LAT and prospects from XENON1T. In addition to the well known LEP bound $M_{Z^{\\prime}}/g_{BL} \\gtrsim 7$ TeV, we include often ignored LHC bounds using 13 TeV dilepton (dimuon+dielectron) data at next-to-leading order plus next-to-leading logarithmic accuracy. We show that, for gauge couplings smaller than $0.4$, the LHC gives rise to the strongest collider limit. In particular, we find $M_{Z^{\\prime}}/g_{BL} > 8.7$ TeV f...

  20. Object Orientated Programmable Integrated Circuit (OOPIC) upgrade and evaluation for Autonomous Ground Vehicle (AGV)

    OpenAIRE

    Hoffman, Andrew J.

    2006-01-01

    A small, low-power Object-Oriented Programmable integrated circuit (OOPic) microcontroller was integrated and tested with the architecture for an autonomous ground vehicle (AGV). Sensors with the OOPic, and the XBee Wireless Suite were included in the integration. Tests were conducted, including range and time operation analysis for wireless communications for comparison with the legacy BL2000 microcontroller. Results demonstrated long battery life for the electronics of the robot, as well as...

  1. The Language of Objects

    DEFF Research Database (Denmark)

    Eskildsen, Kasper Risbjerg

    2012-01-01

    themselves to histories of texts and therefore abandoned the earliest human history. Instead, he proposed a new history of objects, which included the entire history of humankind. Thomsen's work as director of the Royal Museum of Nordic Antiquities in Copenhagen was especially important for this renewal. The...... arrangement of artifacts not only helped him formulate his theories, but also allowed him to present his arguments in a language of objects. At the same time, Thomsen's definition of archaeology as a museum science placed his branch of archaeology in a closer relationship with other museum sciences, such as...

  2. Objective Eulerian coherent structures

    Science.gov (United States)

    Serra, Mattia; Haller, George

    2016-05-01

    We define objective Eulerian Coherent Structures (OECSs) in two-dimensional, non-autonomous dynamical systems as the instantaneously most influential material curves. Specifically, OECSs are stationary curves of the averaged instantaneous material stretching-rate or material shearing-rate functionals. From these objective (frame-invariant) variational principles, we obtain explicit differential equations for hyperbolic, elliptic, and parabolic OECSs. As an illustration, we compute OECSs in an unsteady ocean velocity data set. In comparison to structures suggested by other common Eulerian diagnostic tools, we find OECSs to be the correct short-term cores of observed trajectory deformation patterns.

  3. Objective Eulerian Coherent Structures

    CERN Document Server

    Serra, M

    2015-01-01

    We define objective Eulerian Coherent Structures (OECSs) in two-dimensional, non-autonomous dynamical systems as instantaneously most influential material curves. Specifically, OECSs are stationary curves of the averaged instantaneous material stretching-rate or material shearing-rate functionals. From these objective (frame-invariant) variational principles, we obtain explicit differential equations for hyperbolic, elliptic and parabolic OECSs. As illustration, we compute OECSs in an unsteady ocean velocity data set. In comparison to structures suggested by other common Eulerian diagnostic tools, we find OECSs to be the correct short-term cores of observed trajectory deformation patterns.

  4. Pinocchio: Geppetto's transitional object

    Directory of Open Access Journals (Sweden)

    Gabriele Zeloni

    2015-01-01

    Full Text Available The literature has been considered by Freud and others after him, a form of unaware exploration of mind that can leads to discoveries similar to psychoanalysis’s discoveries. From this perspective, the author puts forward the following hypothesis: Pinocchio is a puppet who comes to life and is therefore, from a child's perception, a transitional object according to Winnicott. Consequently Geppetto is nothing more than the involuntary representation of any child interacting with the transitional object. The author explains the results of the analysis of the text in support of the hypothesis and reflects on the impact of The adventure of Pinocchio on the reader.

  5. Learning Objects Web

    DEFF Research Database (Denmark)

    Blåbjerg, Niels Jørgen

    2005-01-01

    Learning Objects Web er et DEFF projekt som Aalborg Universitetsbibliotek har initieret. Projektet tager afsæt i de resultater og erfaringer som er opnået med vores tidligere projekt Streaming Webbased Information Modules (SWIM). Vi har et internationalt netværk af interessenter som giver os...... sparring og feedback i forhold til udviklingskoncept både omkring de teoretiske rammer og i forhold til praktisk anvendelse af vores undervisningskoncept. Med disse rygstød og input har vi forfulgt ønsket om at videreudvikle SWIM i det nye projekt Learning Objects Web. Udgivelsesdato: juni...

  6. Testing object Interactions

    NARCIS (Netherlands)

    Grüner, Andreas

    2010-01-01

    In this thesis we provide a unit testing approach for multi-purposes object-oriented programming languages in the style of Java and C#. Our approach includes the definition of a test specification language which results from extending the programming language with new designated specification constr

  7. Big Java late objects

    CERN Document Server

    Horstmann, Cay S

    2012-01-01

    Big Java: Late Objects is a comprehensive introduction to Java and computer programming, which focuses on the principles of programming, software engineering, and effective learning. It is designed for a two-semester first course in programming for computer science students.

  8. Technical objectives of inspection

    International Nuclear Information System (INIS)

    The various technical objectives of inspection are discussed in a very general manner. The discussion includes how the inspection function is related to the assumed threat, the various degrees of assurance and reliance on criteria, and the hierarchy of assurance which is obtained from the various types or levels of inspection

  9. Objective pulsatile tinnitus

    OpenAIRE

    Yacovino, Dario A.; Casas, Pablo

    2015-01-01

    Key Clinical Message Tinnitus is the usually unwanted perception of sound, in most cases there is no genuine physical source of sound. Less than 10% of tinnitus patients suffer from pulsatile tinnitus. Objective Pulsatile tinnitus can also be the first indication of dural arteriovenous fistula, so examination for such vascular origin must be performed.

  10. Job Improvement by Objectives.

    Science.gov (United States)

    Westside Community Schools, Omaha, NE.

    This report provides one school district's program for evaluating teachers. The report (1) discusses the philosophy behind the evaluation program, (2) outlines the procedures to be followed, (3) defines the roles of the participants, (4) describes the goals and objectives of the school district, and (5) provides sample instruments used in the…

  11. Microsystems technology: objectives

    NARCIS (Netherlands)

    Fluitman, Jan

    1996-01-01

    This contribution focuses on the objectives of microsystems technology (MST). The reason for this is two fold. First of all, it should explain what MST actually is. This question is often posed and a simple answer is lacking, as a consequence of the diversity of subjects that are perceived as MST. T

  12. Forecasters' Objectives and Strategies

    DEFF Research Database (Denmark)

    Marinovic, Iván; Ottaviani, Marco; Sørensen, Peter Norman

    2013-01-01

    This chapter develops a unified modeling framework for analyzing the strategic behavior of forecasters. The theoretical model encompasses reputational objectives, competition for the best accuracy, and bias. Also drawing from the extensive lit- erature on analysts, we review the empirical evidence...

  13. Enhanced glucose tolerance in pancreatic-derived factor (PANDER) knockout C57BL/6 mice.

    Science.gov (United States)

    Moak, Shari L; Dougan, Grace C; MarElia, Catherine B; Danse, Whitney A; Fernandez, Amanda M; Kuehl, Melanie N; Athanason, Mark G; Burkhardt, Brant R

    2014-11-01

    Pancreatic-derived factor (PANDER; also known as FAM3B) is a uniquely structured protein strongly expressed within and secreted from the endocrine pancreas. PANDER has been hypothesized to regulate fasting and fed glucose homeostasis, hepatic lipogenesis and insulin signaling, and to serve a potential role in the onset or progression of type 2 diabetes (T2D). Despite having potentially pivotal pleiotropic roles in glycemic regulation and T2D, there has been limited generation of stable animal models for the investigation of PANDER function, and there are no models on well-established genetic murine backgrounds for T2D. Our aim was to generate an enhanced murine model to further elucidate the biological function of PANDER. Therefore, a pure-bred PANDER knockout C57BL/6 (PANKO-C57) model was created and phenotypically characterized with respect to glycemic regulation and hepatic insulin signaling. The PANKO-C57 model exhibited an enhanced metabolic phenotype, particularly with regard to enhanced glucose tolerance. Male PANKO-C57 mice displayed decreased fasting plasma insulin and C-peptide levels, whereas leptin levels were increased as compared with matched C57BL/6J wild-type mice. Despite similar peripheral insulin sensitivity between both groups, hepatic insulin signaling was significantly increased during fasting conditions, as demonstrated by increased phosphorylation of hepatic PKB/Akt and AMPK, along with mature SREBP-1 expression. Insulin stimulation of PANKO-C57 mice resulted in increased hepatic triglyceride and glycogen content as compared with wild-type C57BL/6 mice. In summary, the PANKO-C57 mouse represents a suitable model for the investigation of PANDER in multiple metabolic states and provides an additional tool to elucidate the biological function and potential role in T2D. PMID:25217499

  14. Behavioral architecture of opioid reward and aversion in C57BL/6 substrains

    Directory of Open Access Journals (Sweden)

    Camron D Bryant

    2015-01-01

    Full Text Available Drug liking versus drug disliking is a subjective motivational measure in humans that assesses the addiction liability of drugs. Variation in this trait is hypothesized to influence vulnerability versus resilience toward substance abuse disorders and likely contains a genetic component. In rodents and humans, conditioned place preference (CPP / aversion (CPA is a Pavlovian conditioning paradigm whereby a learned preference for the drug-paired environment is used to infer drug liking whereas a learned avoidance or aversion is used to infer drug disliking. C57BL/6 inbred mouse substrains are nearly genetically identical, yet demonstrate robust differences in addiction-relevant behaviors, including locomotor sensitization to cocaine and consumption of ethanol. Here, we tested the hypothesis that B6 substrains would demonstrate differences in the rewarding properties of the mu opioid receptor agonist oxycodone (5 mg/kg, i.p. and the aversive properties of the opioid receptor antagonist naloxone (4 mg/kg, i.p.. Both substrains showed similar degrees of oxycodone-induced CPP; however, there was a three-fold enhancement of naloxone-induced CPA in agonist-naïve C57BL/6J relative to C57Bl/6NJ mice. Exploratory factor analysis of CPP and CPA identified unique factors that explain variance in behavioral expression of reward versus aversion. “Conditioned Opioid-Like Behavior” was a reward-based factor whereby drug-free locomotor variables resembling opioid treatment co-varied with the degree of CPP. “Avoidance and Freezing” was an aversion-based factor, whereby the increase in the number of freezing bouts co-varied with the degree of aversion. These results provide new insight into the behavioral architecture of the motivational properties of opioids. Future studies will use quantitative trait locus mapping in B6 substrains to identify novel genetic factors that contribute to the marked strain difference in NAL-CPA.

  15. Behavioral architecture of opioid reward and aversion in C57BL/6 substrains.

    Science.gov (United States)

    Kirkpatrick, Stacey L; Bryant, Camron D

    2014-01-01

    Drug liking vs. drug disliking is a subjective motivational measure in humans that assesses the addiction liability of drugs. Variation in this trait is hypothesized to influence vulnerability vs. resilience toward substance abuse disorders and likely contains a genetic component. In rodents and humans, conditioned place preference (CPP)/aversion (CPA) is a Pavlovian conditioning paradigm whereby a learned preference for the drug-paired environment is used to infer drug liking whereas a learned avoidance or aversion is used to infer drug disliking. C57BL/6 inbred mouse substrains are nearly genetically identical, yet demonstrate robust differences in addiction-relevant behaviors, including locomotor sensitization to cocaine and consumption of ethanol. Here, we tested the hypothesis that B6 substrains would demonstrate differences in the rewarding properties of the mu opioid receptor agonist oxycodone (5 mg/kg, i.p.) and the aversive properties of the opioid receptor antagonist naloxone (4 mg/kg, i.p.). Both substrains showed similar degrees of oxycodone-induced CPP; however, there was a three-fold enhancement of naloxone-induced CPA in agonist-naïve C57BL/6J relative to C57Bl/6NJ mice. Exploratory factor analysis of CPP and CPA identified unique factors that explain variance in behavioral expression of reward vs. aversion. "Conditioned Opioid-Like Behavior" was a reward-based factor whereby drug-free locomotor variables resembling opioid treatment co-varied with the degree of CPP. "Avoidance and Freezing" was an aversion-based factor, whereby the increase in the number of freezing bouts co-varied with the degree of aversion. These results provide new insight into the behavioral architecture of the motivational properties of opioids. Future studies will use quantitative trait locus mapping in B6 substrains to identify novel genetic factors that contribute to the marked strain difference in NAL-CPA. PMID:25628547

  16. Enhanced glucose tolerance in pancreatic-derived factor (PANDER knockout C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Shari L. Moak

    2014-11-01

    Full Text Available Pancreatic-derived factor (PANDER; also known as FAM3B is a uniquely structured protein strongly expressed within and secreted from the endocrine pancreas. PANDER has been hypothesized to regulate fasting and fed glucose homeostasis, hepatic lipogenesis and insulin signaling, and to serve a potential role in the onset or progression of type 2 diabetes (T2D. Despite having potentially pivotal pleiotropic roles in glycemic regulation and T2D, there has been limited generation of stable animal models for the investigation of PANDER function, and there are no models on well-established genetic murine backgrounds for T2D. Our aim was to generate an enhanced murine model to further elucidate the biological function of PANDER. Therefore, a pure-bred PANDER knockout C57BL/6 (PANKO-C57 model was created and phenotypically characterized with respect to glycemic regulation and hepatic insulin signaling. The PANKO-C57 model exhibited an enhanced metabolic phenotype, particularly with regard to enhanced glucose tolerance. Male PANKO-C57 mice displayed decreased fasting plasma insulin and C-peptide levels, whereas leptin levels were increased as compared with matched C57BL/6J wild-type mice. Despite similar peripheral insulin sensitivity between both groups, hepatic insulin signaling was significantly increased during fasting conditions, as demonstrated by increased phosphorylation of hepatic PKB/Akt and AMPK, along with mature SREBP-1 expression. Insulin stimulation of PANKO-C57 mice resulted in increased hepatic triglyceride and glycogen content as compared with wild-type C57BL/6 mice. In summary, the PANKO-C57 mouse represents a suitable model for the investigation of PANDER in multiple metabolic states and provides an additional tool to elucidate the biological function and potential role in T2D.

  17. Objectives and Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Segalman, D.J.

    1998-11-30

    I have recently become involved in the ABET certification process under the new system - ABET 2000. This system relies heavily on concepts of Total Quality Management (TQM). It encourages each institution to define its objectives in terms of its own mission and then create a coherent program based on it. The prescribed steps in setting up the new system at an engineering institution are: o identification of constituencies G definition of mission. It is expected that the department's mission will be consistent with that of the overall institution, but containing some higher resolution language appropriate to that particular discipline of the engineering profession. o statement of objectives consistent with the mission 3G~~\\vED " enumeration of desired, and preferably measurable, outcomes of the process that would ~ `=. verify satisfaction of the objectives. ~~~ 07 !398 o establish performance standards for each outcome. o creation of appropriate feedback loops to assure that the objectives are still consistent with Q$YT1 the mission, that the outcomes remain consistent with the objectives, and that the curriculum and the teaching result in those outcomes. It is my assertion that once the institution verbalizes a mission, enumerated objectives naturally flow from that mission. (We shall try to demonstrate by example.) Further, if the mission uses the word "engineer", one would expect that word also to appear in at least one of the objectives. The objective of producing engineers of any sort must -by decree - involve the presence of the ABET criteria in the outcomes list. In other words, successful satisfaction of the ABET items a-k are a necessary subset of the measure of success in producing engineers. o We shall produce bachelor level engineers whose training in the core topics of chemical (or electrical, or mechanical) engineering is recognized to be among the best in the nation. o We shall provide an opportunity for our students to gain

  18. Hippocampus-dependent place learning enables spatial flexibility in C57BL6/N mice

    OpenAIRE

    Kleinknecht, Karl R.; Bedenk, Benedikt T.; Kaltwasser, Sebastian F.; Grünecker, Barbara; Yen, Yi-Chun; Czisch, Michael; Wotjak, Carsten T.

    2012-01-01

    Spatial navigation is a fundamental capability necessary in everyday life to locate food, social partners, and shelter. It results from two very different strategies: (1) place learning which enables for flexible way finding and (2) response learning that leads to a more rigid “route following.” Despite the importance of knockout techniques that are only available in mice, little is known about mice' flexibility in spatial navigation tasks. Here we demonstrate for C57BL6/N mice in a water-cro...

  19. Conjugated linoleic acid reduces body weight gain in ovariectomized female C57BL/6J mice

    OpenAIRE

    Kanaya, Noriko; Chen, Shiuan

    2010-01-01

    Estrogen is an important protective factor against obesity in females. Therefore, postmenopausal women have a higher rate of obesity than premenopausal women, which is associated with age-related loss of ovary function. It has been reported that a diet containing conjugated linoleic acid (CLA) reduced body weight and body fat mass in the animal model as well as in human trials. We hypothesized that ingestion of CLA would reduce body weight gain in ovariectomized (OVX) female C57BL/6J mice whi...

  20. Collagenase-3 (MMP-13) deficiency protects C57BL/6 mice from antibody-induced arthritis

    OpenAIRE

    Singh, Anjana; Rajasekaran, Narendiran; Hartenstein, Bettina; Szabowski, Sibylle; Gajda, Mieczyslaw; Angel, Peter; Bräuer, Rolf; Illges, Harald

    2013-01-01

    Introduction Matrix metalloproteinases (MMPs) are important in tissue remodelling. Here we investigate the role of collagenase-3 (MMP-13) in antibody-induced arthritis. Methods For this study we employed the K/BxN serum-induced arthritis model. Arthritis was induced in C57BL/6 wild type (WT) and MMP-13-deficient (MMP-13 –/– ) mice by intraperitoneal injection of 200 μl of K/BxN serum. Arthritis was assessed by measuring the ankle swelling. During the course of the experiments, mice were sacri...

  1. Sterile neutrino portal to Dark Matter I: The $U(1)_{B-L}$ case

    OpenAIRE

    Escudero, Miguel; Rius, Nuria; Sanz, Verónica

    2016-01-01

    In this paper we explore the possibility that the sterile neutrino and Dark Matter sectors in the Universe have a common origin. We study the consequences of this assumption in the simple case of coupling the dark sector to the Standard Model via a global $U(1)_{B-L}$, broken down spontaneously by a dark scalar. This dark scalar provides masses to the dark fermions and communicates with the Higgs via a Higgs portal coupling. We find an interesting interplay between Dark Matter annihilation to...

  2. The Connection among Gamma-ray Burst Host-Galaxies, BL Lacs and Quasars

    OpenAIRE

    Rej, A.

    1999-01-01

    A possible connection among host-galaxies of gamma-ray bursts, BL Lacs and quasars is analysed. It is believed that the gamma-ray bursts, which do not show radio or infrared emission, occur in faint blue dwarf galaxies, that are seen around radio-quiet quasars, which lie in clusters. The GRB counterparts, which show radio emission, may be associated with more evolved starbursting environments, and arise from red galaxies, that are observed around some radio-loud quasars lying in richer cluste...

  3. Functional Analysis of the p40 and p75 Proteins from Lactobacillus casei BL23

    OpenAIRE

    Bäuerl, Christine; Pérez-Martínez, Gaspar; Yan, Fang; Polk, D. Brent; Monedero, Vicente

    2010-01-01

    The genomes of Lactobacillus casei/paracasei and Lactobacillus rhamnosus strains carry two genes encoding homologues of p40 and p75 from L. rhamnosus GG, two secreted proteins which display anti-apoptotic and cell protective effects on human intestinal epithelial cells. p40 and p75 carry cysteine, histidine-dependent aminohydrolase/peptidase (CHAP) and NLPC/P60 domains, respectively, which are characteristic of proteins with cell-wall hydrolase activity. In L. casei BL23 both proteins were se...

  4. Transcriptional profiling of thymidine-producing strain recombineered from Escherichia coli BL21

    Directory of Open Access Journals (Sweden)

    Jin-Sook Kim

    2015-12-01

    Full Text Available DNA microarrays were used to compare the expression profiles of a thymidine overproducing strain (BLT013 and its isogenic parent, Escherichia coli BL21(DE3, when each was grown under well-defined thymidine production conditions with glycerol as carbon source. Here we describe the experimental procedures and methods in detail to reproduce the results and provide resource to be applied to similar engineering approach (available at Gene Expression Omnibus database under GSE69963. Taken together, the microarray data provide a basis for new testable hypotheses regarding enhancement of thymidine productivity and attaining a more complete understanding of nucleotide metabolism in bacteria.

  5. Phenomenology of the minimal B-L extension of the Standard Model at the LHC

    CERN Document Server

    Basso, Lorenzo

    2011-01-01

    A well-motivated framework to naturally introduce neutrino masses is the B-L model, a U(1) extension of the standard model related to the baryon minus lepton gauged number. Besides three right-handed neutrinos, that are included to cancel the anomalies (thereby naturally providing neutrino masses), this model also encompasses a complex scalar for the spontaneous symmetry breaking of the extended gauge sector and to give mass to the Z' boson. We present the phenomenology, the discovery potential at the LHC, and the most up-to-date experimental and theoretical limits of the new particles in this model.

  6. Response of C57Bl/6 mice to a carbohydrate-free diet

    OpenAIRE

    Borghjid Saihan; Feinman Richard

    2012-01-01

    Abstract High fat feeding in rodents generally leads to obesity and insulin resistance whereas in humans this is only seen if dietary carbohydrate is also high, the result of the anabolic effect of poor regulation of glucose and insulin. A previous study of C57Bl/6 mice (Kennedy AR, et al.: Am J Physiol Endocrinol Metab (2007) 262 E1724-1739) appeared to show the kind of beneficial effects of calorie restriction that is seen in humans but that diet was unusually low in protein (5%). In the cu...

  7. Advantame Sweetener Preference in C57BL/6J Mice and Sprague-Dawley Rats

    OpenAIRE

    Sclafani, Anthony; Ackroff, Karen

    2015-01-01

    Advantame is a new ultrahigh-intensity noncaloric sweetener derived from aspartame and approved for human use. Rats and mice are not attracted to the taste of aspartame and this study determined their preference for advantame. In 24-h choice tests with water, C57BL/6J mice and Sprague-Dawley rats were indifferent to advantame at concentrations of 0.01, 0.03, and 0.1mM but significantly preferred 0.3 and 1mM advantame to water. Both species also preferred 1mM advantame to 1mM saccharin in dire...

  8. Sweetener preference of C57BL/6ByJ and 129P3/J mice

    OpenAIRE

    Bachmanov, Alexander A.; Tordoff, Michael G.; Gary K Beauchamp

    2001-01-01

    Previous studies have shown large differences in taste responses to several sweeteners between mice from the C57BL/6ByJ (B6) and 129P3/J (129) inbred strains. The goal of this study was to compare behavioral responses of the B6 and 129 mice to a wider variety of sweeteners. Seventeen sweeteners were tested using two-bottle preference tests with water. Three main patterns of strain differences were evident. First, sucrose, maltose, saccharin, acesulfame, sucralose and SC-45647 were preferred b...

  9. Double Higgs peak in the minimal SUSY B-L model

    OpenAIRE

    Abdallah, W.; Khalil, S; Moretti, S.

    2014-01-01

    Motivated by a $\\sim 3\\sigma$ excess recorded by the CMS experiment at the LHC around a mass of order $\\sim 137$ GeV in $ZZ\\to 4l$ and $\\gamma\\gamma$ samples, we analyse the discovery potential of a second neutral Higgs boson in the Supersymmetric $B-L$ extension of the Standard Model (BLSSM) at the CERN machine. We confirm that a double Higgs peak structure can be generated in this framework, with CP-even Higgs boson masses at $\\sim125$ GeV and $\\sim137$ GeV, unlike the case of the Minimal S...

  10. Mini Force: the (B-L) + xY gauge interaction with a light mediator

    CERN Document Server

    Lee, Hye-Sung

    2016-01-01

    The relevant phenomenology and the best search schemes of a sub-electroweak scale gauge boson can be vastly different depending on its coupling. For instance, the rare decay into a light gauge boson and the high precision parity test can be sensitive if it has an axial coupling. The minimal gauge extension of the standard model with the U(1)_{B-L + xY} requires only three right-handed neutrinos, well-suited with the current neutrino mass and mixing data, and no additional exotic matter fields. We study the light gauge boson of this symmetry in detail including its axial coupling property from the hypercharge shift.

  11. Cytogenetic characteristics and their variability in mice lines BALB/c and C57BL/6

    International Nuclear Information System (INIS)

    Mice lines BALB/c and C57BL/6 differ by the frequency of chromosome aberrations in morrow bone cells. The comparative analysis of the variabilities of a number of cytogenetic characteristics (intra chromosome defects, aneu- and polyploidy, mitotic index, micro nuclear test) in various age groups, season investigations, under influence of radio pollution on these lines is carried out. The least variabilities in both lines were revealed in chromosome aberrations and asynchronous chromatide divisions. The main interline distinctions are observed in the dynamics of polyploidy and in the fraction of mono nucleus lymphocytes with micronuclei and aneuploidy cells

  12. Analysis of cardiovascular dynamics in pulmonary hypertensive C57BL6/J mice

    OpenAIRE

    Tewari, Shivendra G.; Bugenhagen, Scott M.; Wang, Zhijie; Schreier, David A.; Carlson, Brian E.; Chesler, Naomi C; Daniel A Beard

    2013-01-01

    A computer model was used to analyze data on cardiac and vascular mechanics from C57BL6/J mice exposed to 0 (n = 4), 14 (n = 6), 21 (n = 8) and 28 (n = 7) days of chronic hypoxia and treatment with the VEGF receptor inhibitor SUGEN (HySu) to induce pulmonary hypertension. Data on right ventricular pressure and volume, and systemic arterial pressure obtained before, during, and after inferior vena cava occlusion were analyzed using a mathematical model of realistic ventricular mechanics couple...

  13. Produktion av dricksvatten och förnybar el i Bläsinge fiskehamn

    OpenAIRE

    Björquist, Olle

    2010-01-01

    The fishing port of Bläsinge is located on the east coast of Öland, Sweden’s second largest island. Today the port has a limited supply of freshwater. The economic association of the fishing port wants to expand their business, so that they will also include tourist services. To do this the harbor will need a more independant source of freshwater, with a higher quality than the present well. This work includes inquiries of two solutions for extracting freshwater from the Baltic Sea, the Clear...

  14. Purification and Characterization of l-Methionine γ-Lyase from Brevibacterium linens BL2†

    OpenAIRE

    Dias, Benjamin; Weimer, Bart

    1998-01-01

    l-Methionine γ-lyase (EC 4.4.1.11) was purified to homogeneity from Brevibacterium linens BL2, a coryneform bacterium which has been used successfully as an adjunct bacterium to improve the flavor of Cheddar cheese. The enzyme catalyzes the α,γ elimination of methionine to produce methanethiol, α-ketobutyrate, and ammonia. It is a pyridoxal phosphate-dependent enzyme, with a native molecular mass of approximately 170 kDa, consisting of four identical subunits of 43 kDa each. The purified enzy...

  15. Splenomegaly of C57BL/6 mouse by thermal neutron exposure after Borono phenylalanine (BPA) administration

    International Nuclear Information System (INIS)

    BNCT(Boron Neutron Capture Therapy) is a promising clinical method for a kind of tumors by killing cancer cells selectively at the cell level, its research is going on over the world, especially KURRI (Kyoto University Research Reactor Institute) in Japan and MIT (Massachusetts institute of Technology)in USA. For the research in Korea, a neutron irradiation facility was a BNCT facility at Hanaro to support the research of BNCT (basic medical, chemical, physical and biological technology). In the present research, we firstly tried to measure the biological information for the splenomegaly of C57BL/6 mouse by thermal neutron exposure after BPA (boronophenylalanine) admini-stration

  16. PENURUNAN KADAR SIANIDA SINGKONG PAHIT PADA PROSES FERMENTASI CAIR BAKTERI BREVIBACTERIUM LACTOFERMENTEMUM BL-1M76

    OpenAIRE

    Suryana Purawisastra; Heru Yuniati

    2012-01-01

    THE REDUCTION OF THE CYANIDE CONTENT OF BITIER CASSAVA BY THE PROCESS OF LIQUID FERMENTATION USING BREVIBACTERIUM LACTOFERMENTUM BL-1M76.Background: Cassava is one of the important source of carbohydrate in tropical countries, that easliy grows in any kind of soil. However, there is a kind of cassava containing cyanide substance, which is toxic for human consumption. This kind of cassava known as bitter cassava contains more starch, but it can't be used as food directly. Usually, people uses ...

  17. Removal of Grey BL from Dye Wastewater by Derris (Pongamia Glabra) Leaf Powder by Adsorption

    OpenAIRE

    Mugugan, T.; A. Ganapathi; Valliappan, R.

    2010-01-01

    The dye, Grey BL was adsorbed on an adsorbent prepared from mature leaves of the Pungan tree (Pongamia glabra). A batch adsorption study was carried out with variable adsorbate concentration, adsorbent amount and pH. Ninety three percent of the dye could be removed by 2 g of the derris leaf powder from 1 L of an aqueous solution containing 25 mg of the dye at 300 K. The adsorption followed pseudo first order kinetics with a mean rate constant of 3.73 ×10-3 min-1 and an intraparticle diffusion...

  18. Immune-mediated bone marrow failure in C57BL/6 mice

    OpenAIRE

    Chen, Jichun; Desierto, Marie J.; Feng, Xingmin; Biancotto, Angélique; Young, Neal S.

    2014-01-01

    We established a model of immune-mediated bone marrow (BM) failure in C57BL/6 (B6) mice with 6.5 Gy total body irradiation (TBI) followed by the infusion of 4–10 × 106 lymph node (LN) cells/recipient from FVB/N (FVB) donors. Forty-three percent animals succumbed, with surviving animals showing marked declines in blood neutrophils, red blood cells, platelets and total BM cells at 8 to 14 days following LN cell infusion. Lowering the TBI dose to 5 Gys or altering the LN source from FVB to BALB/...

  19. Part Objects and Their Location

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    1992-01-01

    The notion of location of part objects is introduced, yielding a reference to the containing object. Combined with locally defined objects and classes (block structure), singularly defined part objects, and references to part objects, it is a powerful language mechanism for defining objects...... with different aspects or roles. The use of part objects for inheritance of code is also explored....

  20. Learning through New Media Objects

    OpenAIRE

    Karen Woo

    2003-01-01

    This paper compares learning objects with Manovich's new media objects. It shows that learning objects are culturally translated from programming objects through the use of new media in education. Some characteristics of programming objects simply do not apply to learning objects. On this basis, it argues that the grandest promises for learning objects reuse fails both in programming objects and in learning objects. Then it discusses some common issues that faced by new media producers and ...

  1. Observation and Quantum Objectivity

    CERN Document Server

    Healey, Richard

    2012-01-01

    The paradox of Wigner's friend challenges the objectivity of description in quantum theory. A pragmatist interpretation can meet this challenge by judicious appeal to decoherence. On this interpretation, quantum theory provides situated agents with resources for predicting and explaining what happens in the physical world---not conscious observations of it. Even in Wigner's friend scenarios, differently situated agents agree on the objective content of statements about the values of physical magnitudes. In more realistic circumstances quantum Darwinism also permits differently situated agents equal observational access to evaluate their truth. In this view, quantum theory has nothing to say about consciousness or conscious experiences of observers. But it does prompt us to reexamine the significance even of everyday claims about the physical world.

  2. Compact cosmic objects

    International Nuclear Information System (INIS)

    The data are discussed obtained using the method of superfar radiointerferometry. High angular resolution of radiointerferometers with superlong bases has made compact radiosources placed inside and beyond the Galaxy accessable for investigations. Outer galactic objects with extraordinarily active nuclei have been found. Seyfert galaxies 3C84(NGC 1275) in the Perseus constellation and 3C 345 quasar in the Hercules constellation are objects with active nuclei. In the nuclei of separate quasars extraordinarily active processes take place which are accompanied by outflow of clouds of relativistic particles. The velocity of these particles exceeds the light velocity. Measurements with high angular resolution performed in the shortest wave of the centimeter range (1.35 cm) have permitted to find the double nucleus in the Seyfert galaxy NGC 1275. The superfar radiointerferometry has made interesting discoveries when studying gas-dust galactic nebular. Laser sources that emit bright and narrow lines of hydroxyl and water vapour are found in them

  3. Object signing in bamboo

    OpenAIRE

    Smith, Marlon L.

    2000-01-01

    The rapid growth in the Internet has been fueled by an exorbitant number of users, organizations and individuals alike, many relying on e-commerce to conduct business including the transport of files. Public Key Infrastructure (PKI) technology has emerged to the forefront as the basis for ensuring secure transactions throughout the Internet. However, this technology is prohibitively expensive for the majority of users. Object signing technology, a subset of PKI technology, provides a veritabl...

  4. Pinocchio: Geppetto's transitional object

    OpenAIRE

    Gabriele Zeloni

    2015-01-01

    The literature has been considered by Freud and others after him, a form of unaware exploration of mind that can leads to discoveries similar to psychoanalysis’s discoveries. From this perspective, the author puts forward the following hypothesis: Pinocchio is a puppet who comes to life and is therefore, from a child's perception, a transitional object according to Winnicott. Consequently Geppetto is nothing more than the involuntary representation of any child interacting with the transition...

  5. Projective ambidextrous objects

    CERN Document Server

    Geer, Nathan; Patureau-Mirand, Bertrand

    2011-01-01

    We provide a necessary and sufficient condition for a simple object in a pivotal k-category to be ambidextrous. As a consequence we prove that they exist for factorizable ribbon Hopf algebras, modular representations of finite groups and their quantum doubles, complex and modular Lie (super)algebras, the (1,p) minimal model in conformal field theory, and quantum groups at a root of unity.

  6. Objects of consciousness

    OpenAIRE

    Donald David Hoffman; Chetan ePrakash

    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. Moreo...

  7. A thioacetamide-induced hepatic encephalopathy model in C57BL/6 mice: a behavioral and neurochemical study Modelo de encefalopatia hepática induzida por tioacetamida em camundongos C57BL/6: estudo comportamental e neuroquímico

    Directory of Open Access Journals (Sweden)

    Aline Silva de Miranda

    2010-08-01

    Full Text Available OBJECTIVE: Hepatic encephalopathy (HE is a neuropsychiatric syndrome resulting from liver failure. In the present study, we aimed to standardize an animal model of HE induced by thioacetamide (TAA in C57BL/6 mice evaluating behavioral symptoms in association with liver damage and alterations in neurotransmitter release. METHOD: HE was induced by an intraperitoneal single dose of TAA (200 mg/kg, 600 mg/kg or 1,200 mg/kg. Behavioral symptoms were evaluated using the SHIRPA battery. Liver damage was confirmed by histopathological analysis. The glutamate release was measured using fluorimetric assay. RESULTS: The neuropsychiatric state, motor behavior and reflex and sensory functions were significantly altered in the group receiving 600 mg/kg of TAA. Biochemical analysis revealed an increase in the glutamate release in the cerebral cortex of HE mice. CONCLUSION: HE induced by 600mg/kg TAA injection in C57BL/6 mice seems to be a suitable model to investigate the pathogenesis and clinical disorders of HE.OBJETIVO: A encefalopatia hepática (EH é uma síndrome neuropsiquiátrica resultante da falência hepática. O objetivo do presente estudo foi estabelecer um modelo de EH induzida por tioacetamida (TAA em camundongos C57BL/6 avaliando transtornos comportamentais, falência hepática e alterações na liberação de neurotransmissores. MÉTODO: A EH foi induzida por meio de uma única dose intraperitoneal de TAA (200 mg/kg, 600 mg/kg, 1.200 mg/kg. As alterações comportamentais foram avaliadas utilizando a bateria SHIRPA. A falência hepática foi confirmada através de análises histopatológicas e a liberação de glutamato medida, por ensaio fluorimétrico. RESULTADOS: Foram encontradas alterações significativas no estado neuropsiquiátrico, comportamento motor e função reflexa e sensorial no grupo que recebeu 600 mg/kg de TAA. Análises bioquímicas revelaram aumento na liberação de glutamato no córtex cerebral dos camundongos com EH

  8. Semi-shifted hybrid inflation with B-L cosmic strings

    CERN Document Server

    Lazarides, George; Vamvasakis, Achilleas

    2008-01-01

    We discuss a new inflationary scenario which is realized within the extended supersymmetric Pati-Salam model which yields an acceptable b-quark mass for universal boundary conditions and mu>0 by modestly violating Yukawa unification and leads to new shifted, new smooth, or standard-smooth hybrid inflation. Inflation takes place along a "semi-shifted" classically flat direction on which the U(1)_{B-L} gauge group remains unbroken. After the end of inflation, U(1)_{B-L} breaks spontaneously and a network of local cosmic strings, which contribute a small amount to the curvature perturbation, is produced. We show that, in minimal supergravity, this "semi-shifted" inflationary scenario is compatible with a recent fit to data which uses field-theory simulations of a local string network. Taking into account the requirement of gauge unification, we find that, for spectral index n_s=1, the predicted fractional contribution f_{10} of strings to the temperature power spectrum at multipole l=10 is about 0.039. Also, for...

  9. Protein crystallography beamline (PX-BL21) at Indus-2 synchrotron.

    Science.gov (United States)

    Kumar, Ashwani; Ghosh, Biplab; Poswal, H K; Pandey, K K; Hosur, M V; Dwivedi, Abhilash; Makde, Ravindra D; Sharma, Surinder M

    2016-03-01

    The protein crystallography beamline (PX-BL21), installed at the 1.5 T bending-magnet port at the Indian synchrotron (Indus-2), is now available to users. The beamline can be used for X-ray diffraction measurements on a single crystal of macromolecules such as proteins, nucleic acids and their complexes. PX-BL21 has a working energy range of 5-20 keV for accessing the absorption edges of heavy elements commonly used for phasing. A double-crystal monochromator [Si(111) and Si(220)] and a pair of rhodium-coated X-ray mirrors are used for beam monochromatization and manipulation, respectively. This beamline is equipped with a single-axis goniometer, Rayonix MX225 CCD detector, fluorescence detector, cryogenic sample cooler and automated sample changer. Additional user facilities include a workstation for on-site data processing and a biochemistry laboratory for sample preparation. In this article the beamline, other facilities and some recent scientific results are briefly described. PMID:26917153

  10. Immediate epileptogenesis: Impact on brain in C57BL/6J mouse kainate model.

    Science.gov (United States)

    Puttachary, Sreekanth; Sharma, Shaunik; Thippeswamy, Achala; Thippeswamy, Thimmasettappa

    2016-01-01

    We have recently demonstrated immediate epileptogenesis in the C57BL/6J mouse, the strain that is resistant to kainate-induced neurotoxicity. By using a repeated low dose of kainate, we produced mild and severe status epilepticus (SE) models. In the present study, we demonstrate the impact of mild and severe SE, and spontaneous convulsive/nonconvulsive seizures (CS/NCS) on structure and function of the hippocampus, entorhinal cortex, and amygdala at 7, 14 and 28 day post-SE. Immunohistochemistry (IHC) of brain sections confirmed reactive astrogliosis and microgliosis, neurodegeneration, and increased neurogenesis in both groups. The epileptiform spike rate was higher in the severe group during first 12 days, but they decreased thereafter. Morris water maze test confirmed cognitive deficit in both mild and severe groups at 12d post-SE. However, MRI and IHC at 18 weeks did not reveal any changes in the hippocampus. These findings suggest that in C57BL/6J mice, immediate spontaneous CS could be responsible for early brain pathology or vice versa, however, the persistent spontaneous NCS for a long-term had no impact on the brain structure in both groups. PMID:27100347

  11. Minocycline does not evoke anxiolytic and antidepressant-like effects in C57BL/6 mice.

    Science.gov (United States)

    Vogt, M A; Mallien, A S; Pfeiffer, N; Inta, I; Gass, P; Inta, D

    2016-03-15

    Minocycline is a broad-spectrum tetracycline antibiotic with multiple actions, including anti-inflammatory and neuroprotective effects, that was proposed as novel treatment for several psychiatric disorders including schizophrenia and depression. However, there are contradictory results regarding antidepressant effects of minocycline in rodent models. Additionally, the possible anxiolytic effect of minocycline is still poorly investigated. Therefore, we aimed to clarify in the present study the influence of minocycline on behavioral correlates of mood disorders in standard tests for depression and anxiety, the Porsolt Forced Swim Test (FST), Elevated O-Maze, Dark-Light Box Test and Openfield Test in adult C57BL/6 mice. We found, unexpectedly, that mice treated with minocycline (20-40mg/kg, i.p.) did not display antidepressant- or anxiolytic-like behavioral changes in contrast to mice treated with diazepam (0.5mg/kg, anxiety tests) or imipramine (20mg/kg, depressive-like behavior). These results are relevant for future studies, considering that C57BL/6 mice, the most widely used strain in pharmacological and genetic animal models, did not react as expected to the treatment regime applied. PMID:26698398

  12. Respiratory syncytial virus increases lung cellular bioenergetics in neonatal C57BL/6 mice

    International Nuclear Information System (INIS)

    We have previously reported that lung cellular bioenergetics (cellular respiration and ATP) increased in 4–10 week-old BALB/c mice infected with respiratory syncytial virus (RSV). This study examined the kinetics and changes in cellular bioenergetics in ≤2-week-old C57BL/6 mice following RSV infection. Mice (5–14 days old) were inoculated intranasally with RSV and the lungs were examined on days 1–10 post-infection. Histopathology and electron microscopy revealed preserved pneumocyte architectures and organelles. Increased lung cellular bioenergetics was noted from days 1–10 post-infection. Cellular GSH remained unchanged. These results indicate that the increased lung cellular respiration (measured by mitochondrial O2 consumption) and ATP following RSV infection is independent of either age or genetic background of the host. - Highlights: • RSV infection increases lung cellular respiration and ATP in neonatal C57BL/6 mice. • Increased lung cellular bioenergetics is a biomarker of RSV infection. • Lung cellular glutathione remains unchanged in RSV infection

  13. Berberine Nanosuspension Enhances Hypoglycemic Efficacy on Streptozotocin Induced Diabetic C57BL/6 Mice

    Directory of Open Access Journals (Sweden)

    Zhiping Wang

    2015-01-01

    Full Text Available Berberine (Ber, an isoquinoline derivative alkaloid and active ingredient of Coptis, has been demonstrated to possess antidiabetic activities. However its low oral bioavailability restricts its clinical application. In this report, Ber nanosuspension (Ber-NS composed of Ber and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS was prepared by high pressure homogenization technique. Antidiabetic effects of Ber-NS relative to efficacy of bulk Ber were evaluated in streptozotocin (STZ induced diabetic C57BL/6 mice. The particle size and zeta potential of Ber-NS were 73.1 ± 3.7 nm and 6.99 ± 0.17 mV, respectively. Ber-NS (50 mg/kg treatment via oral gavage for 8 weeks resulted in a superior hypoglycemic and total cholesterol (TC and body weight reduction effects compared to an equivalent dose of bulk Ber and metformin (Met, 300 mg/kg. These data indicate that a low dosage Ber-NS decreases blood glucose and improves lipid metabolism in type 2 diabetic C57BL/6 mice. These results suggest that the delivery of Ber as a nanosuspension is a promising approach for treating type 2 diabetes.

  14. Berberine attenuates experimental autoimmune encephalomyelitis in C57 BL/6 mice.

    Directory of Open Access Journals (Sweden)

    Xiaomeng Ma

    Full Text Available BACKGROUND: Berberine, an isoquinoline derivative alkaloid, has a wide range of pharmacological properties and is considered to have anti-inflammatory and neuroprotective effects. However, there are no reports about the effects and mechanisms of berberine in experimental autoimmune encephalomyelitis (EAE, an established model of multiple sclerosis (MS. METHODOLOGY/PRINCIPAL FINDINGS: Female C57 BL/6 mice immunized with myelin oligodendrocyte glycoprotein 35-55 amino acid peptide were treated with berberine at the day of disease onset and medication was administered daily until mice were sacrificed. Blood-brain barrier (BBB permeability and the alteration of matrix metalloproteinase-2 (MMP-2, 72 kDa and matrix metalloproteinase-9 (MMP-9, 92 kDa in the brain and cerebrospinal fluid (CSF of EAE mice were detected by quantitative measurement for Evan's blue (EB content, Western blot and gelatin zymography respectively. The results showed that berberine attenuated clinical and pathological parameters of EAE, reduced the permeability of BBB, inhibited the activity and expression of MMP-9 but not MMP-2 in the CSF and brain of EAE mice. CONCLUSIONS/SIGNIFICANCE: These findings suggest that berberine is effective to attenuate the clinical severity of EAE in C57 BL/6 mice by reducing the permeability of BBB, decreasing the expression and activity of MMP-9, and decreasing the inflammatory infiltration. We think that berberine might be a potential therapeutic agent for MS.

  15. Multi-walled carbon nanotube instillation impairs pulmonary function in C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Walters Dianne M

    2011-08-01

    Full Text Available Abstract Background Multi-walled carbon nanotubes (MWCNTs are widely used in many disciplines due to their unique physical and chemical properties. Therefore, some concerns about the possible human health and environmental impacts of manufactured MWCNTs are rising. We hypothesized that instillation of MWCNTs impairs pulmonary function in C57BL/6 mice due to development of lung inflammation and fibrosis. Methods MWCNTs were administered to C57BL/6 mice by oropharyngeal aspiration (1, 2, and 4 mg/kg and we assessed lung inflammation and fibrosis by inflammatory cell infiltration, collagen content, and histological assessment. Pulmonary function was assessed using a FlexiVent system and levels of Ccl3, Ccl11, Mmp13 and IL-33 were measured by RT-PCR and ELISA. Results Mice administered MWCNTs exhibited increased inflammatory cell infiltration, collagen deposition and granuloma formation in lung tissue, which correlated with impaired pulmonary function as assessed by increased resistance, tissue damping, and decreased lung compliance. Pulmonary exposure to MWCNTs induced an inflammatory signature marked by cytokine (IL-33, chemokine (Ccl3 and Ccl11, and protease production (Mmp13 that promoted the inflammatory and fibrotic changes observed within the lung. Conclusions These results further highlight the potential adverse health effects that may occur following MWCNT exposure and therefore we suggest these materials may pose a significant risk leading to impaired lung function following environmental and occupational exposures.

  16. Respiratory syncytial virus increases lung cellular bioenergetics in neonatal C57BL/6 mice

    Energy Technology Data Exchange (ETDEWEB)

    Alsuwaidi, Ahmed R., E-mail: alsuwaidia@uaeu.ac.ae [Departments of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain (United Arab Emirates); Albawardi, Alia, E-mail: alia.albawardi@uaeu.ac.ae [Departments of Pathology, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain (United Arab Emirates); Almarzooqi, Saeeda, E-mail: saeeda.almarzooqi@uaeu.ac.ae [Departments of Pathology, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain (United Arab Emirates); Benedict, Sheela, E-mail: sheela.benedict@uaeu.ac.ae [Departments of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain (United Arab Emirates); Othman, Aws R., E-mail: aws.rashad@uaeu.ac.ae [Departments of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain (United Arab Emirates); Hartwig, Stacey M., E-mail: stacey-hartwig@uiowa.edu [Department of Microbiology, Department of Pathology and Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA 52242 (United States); Varga, Steven M., E-mail: steven-varga@uiowa.edu [Department of Microbiology, Department of Pathology and Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA 52242 (United States); Souid, Abdul-Kader, E-mail: asouid@uaeu.ac.ae [Departments of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain (United Arab Emirates)

    2014-04-15

    We have previously reported that lung cellular bioenergetics (cellular respiration and ATP) increased in 4–10 week-old BALB/c mice infected with respiratory syncytial virus (RSV). This study examined the kinetics and changes in cellular bioenergetics in ≤2-week-old C57BL/6 mice following RSV infection. Mice (5–14 days old) were inoculated intranasally with RSV and the lungs were examined on days 1–10 post-infection. Histopathology and electron microscopy revealed preserved pneumocyte architectures and organelles. Increased lung cellular bioenergetics was noted from days 1–10 post-infection. Cellular GSH remained unchanged. These results indicate that the increased lung cellular respiration (measured by mitochondrial O{sub 2} consumption) and ATP following RSV infection is independent of either age or genetic background of the host. - Highlights: • RSV infection increases lung cellular respiration and ATP in neonatal C57BL/6 mice. • Increased lung cellular bioenergetics is a biomarker of RSV infection. • Lung cellular glutathione remains unchanged in RSV infection.

  17. Linear seesaw neutrinos in a scenario of gauged B-L symmetry

    CERN Document Server

    Dib, Claudio O; Neill, Nicolas A

    2014-01-01

    We consider a mechanism for neutrino mass generation, based on a local B-L extension of the standard model, which becomes a linear seesaw regime for light neutrinos after spontaneous symmetry breaking. The spectrum of extra particles includes a heavy Z' boson, a pair charged scalars, one standard Higgs and three extra neutral scalars, as well as heavy neutrinos with masses near the TeV scale. We study the production and decays of these heavy particles at the LHC. Z' will decay mainly into heavy neutrino pairs or charged lepton pairs, similar to other low scale seesaw scenarios with local B-L, while the phenomenology of the heavier scalars is specific to this model, in general with suppressed couplings to standard model particles and with decay patterns that depend on the different kinematic thresholds that are open. One of the neutral scalars is produced by Z' Z' fusion and would decay mainly into vector boson pairs or heavy neutrinos. The other two neutral scalars will be difficult to detect as they decay on...

  18. Spontaneous B-L breaking as the origin of the hot early universe

    Energy Technology Data Exchange (ETDEWEB)

    Buchmueller, W.; Domcke, V.; Schmitz, K.

    2012-03-15

    The decay of a false vacuum of unbroken B-L symmetry is an intriguing and testable mechanism to generate the initial conditions of the hot early universe. If B-L is broken at the grand unification scale, the false vacuum phase yields hybrid inflation, ending in tachyonic preheating. The dynamics of the B - L breaking Higgs field and thermal processes produce an abundance of heavy neutrinos whose decays generate entropy, baryon asymmetry and gravitino dark matter. We study the phase transition for the full supersymmetric Abelian Higgs model. For the subsequent reheating process we give a detailed time-resolved description of all particle abundances. The competition of cosmic expansion and entropy production leads to an intermediate period of constant 'reheating' temperature, during which baryon asymmetry and dark matter are produced. Consistency of hybrid inflation, leptogenesis and gravitino dark matter implies relations between neutrino parameters and superparticle masses, in particular a lower bound on the gravitino mass of 10 GeV.

  19. Immunoprevention of x-ray-induced leukemias in the C57BL mouse

    International Nuclear Information System (INIS)

    An attempt to prevent irradiation-induced thymic lymphomas in C57BL mice was made by inducing active immunity to endogenous type-C virus with inactivated Rauscher murine leukemia virus (MuLV) or inactivated Gross MuLV or by transferring passive immunity to endogenous type-C virus with goat anti-Gross-MuLV IgG. Control groups received the following immunogen or treatment: inactivated simian sarcoma virus, complete Freund's adjuvant, normal goat IgG, and diluent, in both irradiated and nonirradiated C57BL mice. Active immunity to the 70,000 molecular weight glycoprotein AKR-gp70 by immunization with Rauscher MuLV and passive immunity to AKR-gp70 by passive transfer of goat anti-Gross-MuLV IgG was measurable throughout some of the latent period of tumor development; in these two groups a significant reduction in tumor incidence was observed, as compared to the other experimental and control groups. Thus, the present findings support the concept of a type-C virus etiology of irradiation-induced leukemias and demonstrate the applicability of immunologic techniques directed against the endogenous type-C virus in the prevention of this disease

  20. EFEK IMUNOMODULATOR EKSTRAK AIR CINCAU HITAM (Mesona palustris BL TERHADAP KARSINOGENESIS MENCIT [Immunomodulatory Effects of Water Extracts of Black Cincau (Mesona palustris BL on Carcinogenesis in Mice

    Directory of Open Access Journals (Sweden)

    Tri Dewanti W.1*

    2012-06-01

    Full Text Available Janggelan or black cincau (Mesona palustris BL is commonly consumed as dessert and also used as herbal remedy in the folk medicine. This study aimed to test the potency of water extract of black cincau in inhibiting fibrosarcoma cancer induced by benzo(apyrene. Mice used in this study were divided into 6 groups. Solution of benzo(apyrene 0.3% was given during two days for five times to induce cancer. Water extract of black cincau at concentration of 100, 500 and 1000 mg/kg BW was given daily for 2 weeks before initiation (induction of benzo(apyrene during the initiation and until 4 weeks after initiation. The IFN-γ was observed with IFN-y ELISA Kit immunosurveillance parameters while the CD8+, NK cells and macrophages were observed with a flow cytometer. Cancer incidence was observed by palpation every week until 10 weeks after benzo(apyrene last induction. The results showed that a high dose of water extract of black cincau (1000 mg/kg BW increased IFN-γ expression and immunosurveillance of CD8+, NK cells and macrophages of the mice. The treatment also increased cell apoptosis and reduced the cancer incidence in mice by 57%.