WorldWideScience

Sample records for lac object 1es

  1. Long-term spectral and temporal behavior of the high-frequency peaked BL LAC object 1ES 1959+650

    Science.gov (United States)

    Backes, M.; Uellenbeck, M.; Hayashida, M.; Satalecka, K.; Tescaro, D.; Terzić, T.; MAGIC Collaboration; Fuhrmann, L.; Nestoras, I.; F-GAMMA project; Lähteenmäki, A.; Tornikoski, M.; Nieppola, E.; Metsähovi; Böttcher, M.; Collmar, W.; Weidinger, M.

    2012-12-01

    The high-frequency peaked BL Lac object 1ES 1959+650 is well-known for an exceptional outburst, which was observed at very high energy (VHE) γ-rays by the Whipple 10m and HEGRA telescopes in 2002. Remarkably, this outburst lacked associated X-ray emission (a socalled "orphan flare") and by this cannot easily be described by standard Synchrotron Self Compton (SSC) models. Models based on hadronic emission processes have also been proposed to explain the observed behavior. Subsequent multi-wavelength observations during a low flux state at TeV energies in 2006 can, instead, be explained by a standard single-zone SSC model. In this context, 1ES 1959+650 has been regularly monitored by the MAGIC telescope since 2005. During these years, no significant variation in the VHE γ-ray flux has been observed. The low energy part of this is in very good agreement with the high-energy part of the time-integrated energy spectrum as measured by Fermi-LAT. Based on this constant flux level in VHE γ-rays, we assembled the time-integrated spectral energy distribution (SED) of 1ES 1959+650 from radio to VHE γ-rays. Despite the non-variability at very high energies, significant flux and spectral variations have been observed at optical and X-ray frequencies in the meanwhile. Furthermore, the shape of the SED at high energy γ-rays as measured by Fermi-LAT is essentially flat which cannot be explained by either conventional single-zone SSC models, or models invoking external radiation fields (EC).

  2. A Multiwavelength Study of Flaring Activity in the High-energy Peaked BL Lac Object 1ES 1959+650 During 2015–2016

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Navpreet; Chandra, S.; Baliyan, Kiran S; Sameer; Ganesh, S. [Astronomy and Astrophysics Division, Physical Research Laboratory, Ahmedabad, Gujarat 380009 (India)

    2017-09-10

    We present the results from a multiwavelength study of the flaring activity in the high-energy peaked BL Lac object 1ES 1959+650 during 2015 January–2016 June. The source underwent two major outbursts, during 2015 March and 2015 October, across the whole electromagnetic spectrum (EMS). We used data from Fermi -LAT and Swift -XRT/UVOT, and optical data from Mt. Abu InfraRed Observatory and Steward Observatory to look for possible correlations between the emissions at different energies and the nature of the variability during the flaring state. During the 2015 October outburst, the nightly averaged V -band brightest magnitude, 14.45(0.03), and faintest magnitude, 14.45(0.03), were recorded. Apart from long-term flares, rapid and short-term variabilities were noticed at all energies. Our study suggests that the flaring activities at all frequencies, with diverse flare durations and time lags, are correlated. The magnetic field strength is estimated to be 4 G using the synchrotron-cooling timescale (2.3 hr), and the upper limits on the sizes of both emission regions, γ -ray and optical, are estimated to be of the order of 10{sup 16} cm. The quasi-simultaneous flux enhancements in 15 GHz and VHE γ -ray emissions indicate a fresh injection of plasma into the jet, which interacts with a standing submillimeter core, resulting in co-spatial emissions across the EMS. The synchrotron peak shifts to higher frequency in the spectral energy distribution while the γ -ray spectra softens during the flaring. The shape of the inverse-Compton spectra indicates a change in the particle energy distribution pre- and post-flare.

  3. Properties of BL Lac objects

    International Nuclear Information System (INIS)

    Wolfe, A.M.; Pittsburgh, University, Pittsburgh, Pa.)

    1980-01-01

    The properties of BL Lacertae objects are examined in light of their recently realized similarities to quasars and associations with galactic radiation. The criteria typically used to define BL Lac objects are analyzed, with attention given to radio spectra, optical continual, radio and optical variability, optical polarization and emission lines, and evidence that BL Lac objects and optically violent variables represent the most compact and strongly variable sources among the general class of quasars is discussed. Connections between BL Lac objects and the galaxies in which they have been observed to be embedded are discussed and it is pointed out that no low-luminosity quasars have been found to be associated with first-ranked giant ellipticals. Future observations which may clarify the properties and relationships of BL Lac objects are indicated

  4. 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.

  5. Evolutionary behaviour of AGN: Investigations on BL Lac objects and Seyfert II galaxies

    Science.gov (United States)

    Beckmann, V.

    2000-12-01

    The evolution and nature of AGN is still one of the enigmatic questions in astrophysics. While large and complete Quasar samples are available, special classes of AGN, like BL Lac objects and Seyfert II galaxies, are still rare objects. In this work I present two new AGN samples. The first one is the HRX-BL Lac survey, resulting in a sample of X-ray selected BL Lac objects. This sample results from 223 BL Lac candidates based on a correlation of X-ray sources with radio sources. The identification of this sample is 98% complete. 77 objects have been identified as BL Lac objects and form the HRX-BL Lac complete sample, the largest homogeneous sample of BL Lac objects existing today. For this sample, redshifts are now known for 62 objects (81 %). In total I present 101 BL Lac objects in the enlarged HRX-BL Lac survey, for which redshift information is available for 84 objects. During the HRX-BL Lac survey I found several objects of special interest. 1ES 1517+656 turned out to be the brightest known BL Lac object in the universe. 1ES 0927+500 could be the first BL Lac object with a line detected in the X-ray region. RX J1211+2242 is probably the the counterpart of the up to now unidentified gamma-ray source 3EG J1212+2304. Additionally I present seven candidates for ultra high frequency peaked BL Lac objects. RX J1054+3855 and RX J1153+3517 are rare high redshift X-ray bright QSO or accreting binary systems with huge magnetic fields. For the BL Lac objects I suggest an unified scenario in which giant elliptical galaxies, formed by merging events of spiral galaxies at z > 2, start as powerful, radio dominated BL Lacs. As the jet gets less powerful, the BL Lacs start to get more X-ray dominated, showing less total luminosities (for z definition to objects with a calcium break up to 40%, but do not support for the HBL the idea of allowing emission lines in the spectra of BL Lac galaxies. A way to find high redshift BL Lac objects might be the identification of faint X

  6. Infrared polarimetry and photometry of BL Lac objects. 3

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, P A; Brand, P W.J.L. [Edinburgh Univ. (UK). Dept. of Astronomy; Impey, C D [Hawaii Univ., Honolulu (USA). Inst. for Astronomy; Williams, P M [UKIRT, Hilo, HI (USA)

    1984-10-15

    The data presented here is part of a continuing monitoring programme of BL lac objects with J, H and K photometry and polarimetry. A total of 30 BL Lac objects have now been observed photometrically. Infrared polarimetry has also been obtained for 24 of these objects. The sample is sufficiently large to examine statistically, and several important correlations have emerged. Internight variations and wavelength dependence of polarization indicate that BL Lac objects, as a class, may be understood in terms of a relatively simple two-component model.

  7. On the Redshift of TeV BL Lac Objects

    Energy Technology Data Exchange (ETDEWEB)

    Paiano, Simona; Falomo, Renato [INAF, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5 I-35122 Padova (PD) (Italy); Landoni, Marco; Righi, Chiara [INAF, Osservatorio Astronomico di Brera, Via E. Bianchi 46 I-23807 Merate (Italy); Treves, Aldo [Università degli Studi dell’Insubria, Via Valleggio 11 I-22100 Como (Italy); Scarpa, Riccardo [Instituto de Astrofisica de Canarias, C/O Via Lactea, s/n E38205—La Laguna (Tenerife) (Spain)

    2017-03-10

    We report results of a spectroscopic campaign carried out at the 10 m Gran Telescopio Canarias for a sample of 22 BL Lac objects detected (or candidates) at TeV energies, aiming to determine or constrain their redshift. This is of fundamental importance for the interpretation of their emission models and for population studies and is also mandatory for studying the interaction of high-energy photons with the extragalactic background light using TeV sources. Optical spectra with high signal-to-noise ratios in the range 4250–10000 Å were obtained to search for faint emission or absorption lines from both the host galaxy and the nucleus. We determine a new redshift for PKS 1424+240 ( z = 0.604) and a tentative one for 1ES 0033+595 ( z = 0.467). We are able to set new spectroscopic redshift lower limits for three other sources on the basis of Mg ii and Ca ii intervening absorption features: BZB J1243+3627 ( z > 0.483), BZB J1540+8155 ( z > 0.672), and BZB 0J2323+4210 ( z > 0.267). We confirm previous redshift estimates for four blazars: S3 0218+357 ( z = 0.944), 1ES 1215+303 ( z = 0.129), W Comae ( z = 0.102), and MS 1221.8+2452 ( z = 0.218). For the remaining targets, in seven cases (S2 0109+22, 3C 66A, VER J0521+211, S4 0954+65, BZB J1120+4214, S3 1227+25, BZB J2323+4210), we do not validate the proposed redshift. Finally, for all sources of still-unknown redshift, we set a lower limit based on the minimum equivalent width of absorption features expected from the host galaxy.

  8. Optical Spectra Evolution of BL Lac Objects XW Bi1,∗ , BZ Wang2

    Indian Academy of Sciences (India)

    low-frequency peaked BL Lac objects (LBLs) is steeper than the high- frequency peaked BL Lac ... vision of BL Lac objects. Many investigators .... We are grateful to the Scientific Research Foundation of the Education Department of Yunnan ...

  9. Infrared polarimetry and photometry of BL Lac objects

    Energy Technology Data Exchange (ETDEWEB)

    Impey, C D; Brand, P W.J.L. [Edinburgh Univ. (UK); Wolstencroft, R D; Williams, P M [Royal Observatory, Edinburgh (UK)

    1982-07-01

    Infrared polarimetry and photometry have been obtained for a sample of 18 BL Lac objects. The data covers a period of one year and is part of a continuing monitoring programme; all observations were in the J,H and K wavebands. Large and variable degrees of polarization are a common property of the sample. Two BL Lac objects show wavelength-dependent polarization, with the polarization increasing towards shorter wavelengths, and two objects show evidence for position angle rotations over a five-day period. The relationship between changes in polarized and total flux is also discussed. The BL Lac objects cover an enormous range of infrared luminosity; the three most luminous having Lsub(IR) > 10/sup 46/ erg s/sup -1/ and the other end of the range having infrared luminosities similar to normal elliptical galaxies. These are the first published infrared polarimetric observations for eight of the sample.

  10. Time-dependent inhomogeneous jet models for BL Lac objects

    Science.gov (United States)

    Marlowe, A. T.; Urry, C. M.; George, I. M.

    1992-05-01

    Relativistic beaming can explain many of the observed properties of BL Lac objects (e.g., rapid variability, high polarization, etc.). In particular, the broadband radio through X-ray spectra are well modeled by synchrotron-self Compton emission from an inhomogeneous relativistic jet. We have done a uniform analysis on several BL Lac objects using a simple but plausible inhomogeneous jet model. For all objects, we found that the assumed power-law distribution of the magnetic field and the electron density can be adjusted to match the observed BL Lac spectrum. While such models are typically unconstrained, consideration of spectral variability strongly restricts the allowed parameters, although to date the sampling has generally been too sparse to constrain the current models effectively. We investigate the time evolution of the inhomogeneous jet model for a simple perturbation propagating along the jet. The implications of this time evolution model and its relevance to observed data are discussed.

  11. Can blueshifted Agn spectra explain B L Lac objects

    International Nuclear Information System (INIS)

    Basu, D.

    2009-01-01

    B L Lac spectra are almost completely devoid of any emission line, and absorption features are often present based on which redshifts are estimated. Several models have been proposed to explain the spectra, including the unification scheme currently most popular among astronomers. However, there appear to be ambiguities, uncertainties and contradictory results in this model, and many questions remain unanswered. Also, it involves the process of artificially enhancing the continuum to be concentrated to a high level, by the relativistically beaming jet action, in order to submerge the emission lines, partly or completely, to make them appear weak or invisible. Additionally, the sample based on which B L Lac objects have been included in the unification scheme is rather small to be statistically viable. In this context, we present an alternative and much simpler interpretation of the observed spectra of B L Lac objects, both emission and absorption, as blueshifted lines in Agn. Original spectra of fifty six objects available in the current literature are re-analyzed. Nine of these show only a single weak emission line and no absorption feature, while thirty five exhibit no emission feature but several absorption lines, and another twelve show more than one emission line and, in some cases, several absorption lines. It is demonstrated that emission lines in most B L Lac objects are blueshifted out of the visible region, and, hence, not seen at all. Emission lines, when seen, and absorption lines, are blueshifted and are identified with search lines of longer wavelengths that are naturally weak. Blue shifts, in emission and absorption features, are determined for all objects. Various considerations lead to the conclusion that the blue shift interpretation of B L Lac spectra is superior to and more important than the redshift interpretation. A possible explanation of observed blue shifts is presented in the scenario of the ejection process, a well-recognized mechanism

  12. Infrared polarimetry and photometry of BL Lac objects. 2

    Energy Technology Data Exchange (ETDEWEB)

    Impey, C D [Hawaii Univ., Honolulu (USA). Inst. for Astronomy; Brand, P W.J.L. [Edinburgh Univ. (UK). Dept. of Astronomy; Wolstencroft, R D [Royal Observatory, Edinburgh (UK); Williams, P M [United Kingdom Infrared Telescope Unit, Hilo, Hawaii (USA)

    1984-07-15

    Photometry and polarimetry in the JHK wavebands have now been obtained for 25 BL Lac objects. Several new objects have been monitored for periods of up to five days, and accumulated data is sufficient for a statistical analysis of polarization properties. The selection effects operating on this sample are examined first. A power-law spectrum is consistent with the spectra of all but three objects. A number of important new results are reported.

  13. Infrared polarimetry and photometry of BL Lac objects

    International Nuclear Information System (INIS)

    Impey, C.D.; Williams, P.M.

    1984-01-01

    Photometry and polarimetry in the JHK wavebands have now been obtained for 25 BL Lac objects. Several new objects have been monitored for periods of up to five days, and accumulated data is sufficient for a statistical analysis of polarization properties. The selection effects operating on this sample are examined first. A power-law spectrum is consistent with the spectra of all but three objects. A number of important new results are reported. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, Sarah Sabine

    2012-12-21

    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

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

    International Nuclear Information System (INIS)

    Kaufmann, Sarah Sabine

    2012-01-01

    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

  16. Long term monitoring of Gamma-Ray emission from the BL Lacertae object (1ES 2200+420)

    Science.gov (United States)

    Gunawardhana, Isuru; VERITAS Collaboration

    2016-03-01

    Blazars are a class of Active Galactic Nuclei (AGN) that have relativistic jets pointing along the observer line of sight. Blazars exhibit variable emission extending from radio to TeV energies. The variability timescale of the TeV flux is a key component of understanding the location of the very high energy emission zones. Deep observations of the quiescent state measurements are also required to disentangle the flaring state emission from quiescent state emission, a prerequisite for understanding the origin of blazar spectral variability. BL Lacertae (also known as 1ES 2200+420), as the namesake for all BL Lac objects, is a prime example of one such blazar. The VERITAS Observatory, an Imaging Atmospheric Cherenkov Telescope (IACT) array sensitive to gamma rays in the range from 85 GeV to 30 TeV, dedicates approximately 110 hours per year on deep observations of known gamma-ray blazars. In this talk, I will describe the TeV photon flux variability of BL Lacertae measured by VERITAS from 2013 to 2015.

  17. The BL Lac objects PKS 1144-379

    International Nuclear Information System (INIS)

    Nicolson, G.D.; Glass, I.S.; Feast, M.W.; Andrews, P.J.

    1979-01-01

    The highly variable radio source PKS 1144-379 has been monitored at 13 cm and 6 cm over a period of 3 years. It has been identified with an object whose photographic image is star-like. From infrared photometry, UBVRsub(KC)Isub(KC) photometry and spectroscopy, it is concluded that PKS 1144-379 is a BL Lac object with msub(v) approximately = 16.2. (author)

  18. RADIO-WEAK BL LAC OBJECTS IN THE FERMI ERA

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F.; Marchesini, E. J. [Dipartimento di Fisica, Università degli Studi di Torino (UniTO), via Pietro Giuria 1, I-10125 Torino (Italy); D’Abrusco, R.; Smith, Howard A. [Smithsonian Astrophysical Observatory, 60 Garden Street, 02138 Cambridge, MA (United States); Masetti, N. [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna, via Gobetti 101, I-40129, Bologna (Italy); Andruchow, I. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, B1900FWA, La Plata (Argentina)

    2017-01-10

    The existence of “radio-weak BL Lac objects” (RWBLs) has been an open question, and has remained unsolved since the discovery that quasars could be radio-quiet or radio-loud. Recently, several groups identified RWBL candidates, mostly found while searching for low-energy counterparts of the unidentified or unassociated gamma-ray sources listed in the Fermi catalogs. Confirming RWBLs is a challenging task since they could be confused with white dwarfs (WDs) or weak emission line quasars (WELQs) when there are not sufficient data to precisely draw their broadband spectral energy distribution, and their classification is mainly based on a featureless optical spectra. Motivated by the recent discovery that Fermi BL Lacs appear to have very peculiar mid-IR emission, we show that it is possible to distinguish between WDs, WELQs, and BL Lacs using the [3.4]–[4.6]–[12] μ m color–color plot built using the WISE magnitudes when the optical spectrum is available. On the basis of this analysis, we identify WISE J064459.38+603131 and WISE J141046.00+740511.2 as the first two genuine RWBLs, both potentially associated with Fermi sources. Finally, to strengthen our identification of these objects as true RWBLs, we present multifrequency observations for these two candidates to show that their spectral behavior is indeed consistent with that of the BL Lac population.

  19. RADIO-WEAK BL LAC OBJECTS IN THE FERMI ERA

    International Nuclear Information System (INIS)

    Massaro, F.; Marchesini, E. J.; D’Abrusco, R.; Smith, Howard A.; Masetti, N.; Andruchow, I.

    2017-01-01

    The existence of “radio-weak BL Lac objects” (RWBLs) has been an open question, and has remained unsolved since the discovery that quasars could be radio-quiet or radio-loud. Recently, several groups identified RWBL candidates, mostly found while searching for low-energy counterparts of the unidentified or unassociated gamma-ray sources listed in the Fermi catalogs. Confirming RWBLs is a challenging task since they could be confused with white dwarfs (WDs) or weak emission line quasars (WELQs) when there are not sufficient data to precisely draw their broadband spectral energy distribution, and their classification is mainly based on a featureless optical spectra. Motivated by the recent discovery that Fermi BL Lacs appear to have very peculiar mid-IR emission, we show that it is possible to distinguish between WDs, WELQs, and BL Lacs using the [3.4]–[4.6]–[12] μ m color–color plot built using the WISE magnitudes when the optical spectrum is available. On the basis of this analysis, we identify WISE J064459.38+603131 and WISE J141046.00+740511.2 as the first two genuine RWBLs, both potentially associated with Fermi sources. Finally, to strengthen our identification of these objects as true RWBLs, we present multifrequency observations for these two candidates to show that their spectral behavior is indeed consistent with that of the BL Lac population.

  20. Six-year optical monitoring of the BL Lacertae object 1ES 0806+52.4

    Energy Technology Data Exchange (ETDEWEB)

    Man, Zhongyi; Zhang, Xiaoyuan; Wu, Jianghua [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Zhou, Xu [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing 100012 (China); Yuan, Qirong, E-mail: jhwu@bnu.edu.cn [Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210046 (China)

    2014-12-01

    We present the results of the first systematic long-term multicolor 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 2005 December to 2011 February. The overall brightness of this object decreased from 2005 December to 2008 December but was regained after that. A sharp outburst probably occurred around the end of our monitoring program. Overlapping the long-term trend are some short-term small-amplitude oscillations. No intranight variability was found in the object, which is in accordance with the historical observations before 2005. By investigating the color behavior, we found a 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 mag, respectively. The amplitudes tend to increase toward shorter wavelengths, which may be a major cause of the bluer-when-brighter chromatism. Such bluer-when-brighter chromatisms are also found in other blazars, such as S5 0716+714, OJ 287. The hard-X-ray data collected from the Swift/BAT archive was correlated with our optical data. No positive result was found, the reason for which may be that the hard-X-ray flux is a combination of the synchrotron and inverse Compton emission, but with different timescales and cadences under the leptonic synchrotron self-Compton model.

  1. Optical polarimetry of quasi-stellar and BL Lac objects

    International Nuclear Information System (INIS)

    Wills, D.; Wills, B.J.; Breger, M.; Hsu, J.

    1980-01-01

    We report observations of 39 extragalactic objects, using a new polarimeter at McDonald Observatory. Most of the observations were made in January and June 1980. Some new BL Lac objects were found, and some of the previously known members of this class were also observed. Polarization exceeding 3--4 times the formal rms uncertainties was found in about ten QSO's. Rapid changes of polarization and/or position angle occurred in some of the BL Lacertae objects, usually with <0.1-mag change in the total light

  2. Polarization burst in the BL Lac object AO 0235 + 164

    Energy Technology Data Exchange (ETDEWEB)

    Impey, C D; Brand, P W.J.L. [Edinburgh Univ. (UK). Dept. of Astronomy; Tapia, S [Steward Observatory, Tucson, AZ (USA)

    1982-01-01

    Simultaneous infrared and optical polarimetry and photometry have been obtained for AO 0235 + 164 covering a five night period. The object underwent a polarization burst during which the 2.2 ..mu..m polarization rose from 17.5 to 28.7 per cent and fell again to 14.9 per cent. At its peak the degree of optical polarization was 43.9 per cent, the highest linear polarization observed in a BL Lac object. The data show the degree of polarization to increase towards shorter wavelengths, and the effect is inconsistent with either dilution by a galactic component or simple one-component synchrotron models. The large changes in polarization are not accompanied by large changes in flux, a result which is difficult to explain using conventional models of these objects. Other implications of the luminosity, polarization and variability are discussed.

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

    International Nuclear Information System (INIS)

    Perry, J.J.; Burbidge, E.M.; Burbidge, G.R.

    1978-06-01

    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.) [de

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

    International Nuclear Information System (INIS)

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

    1984-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

    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.

  6. Computing Optical Variable Periods of BL Lac Object S5 0716+ 714 ...

    Indian Academy of Sciences (India)

    Computing Optical Variable Periods of BL Lac Object S5 0716+ 714 ... The study of long-term periodical variation is an important way to get the charac- ... continuous Fourier transform together, define a window function, and finally obtain.

  7. Spectroscopy of optically selected BL Lac objects and their γ-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Sandrinelli, A.; Treves, A.; Farina, E. P.; Landoni, M. [Università degli Studi dell' Insubria, Via Valleggio 11, I-22100 Como (Italy); Falomo, R. [INAF-Osservatorio Astronomico di Padova, Vicolo dell Osservatorio 5, I-35122 Padova (Italy); Foschini, L.; Sbarufatti, B., E-mail: angela.sandrinelli@brera.inaf.it [INAF-Osservatorio Astronomico di Brera, Via Emilio Bianchi 46, I-23807 Merate (Italy)

    2013-12-01

    We present Very Large Telescope optical spectroscopy of nine BL Lac objects of unknown redshift belonging to the list of optically selected radio-loud BL Lac candidates. We explore their spectroscopic properties and possible link with gamma-ray emission. From the new observations we determine the redshifts of four objects from faint emission lines or from absorption features of their host galaxies. In three cases we find narrow intervening absorptions from which a lower limit to the redshift is inferred. For the remaining two featureless sources, lower limits to the redshift are deduced from the absence of spectral lines. A search for γ counterpart emission shows that six out of the nine candidates are Fermi γ-ray emitters and we find two new detections. Our analysis suggests that most of the BL Lac objects still lacking redshift information are most likely located at high redshifts.

  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

  9. Computing Optical Variable Periods of BL Lac Object S5 0716+714 ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... 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.

  10. X-ray emission from BL Lac objects: Comparison to the synchrotron self-Compton models

    International Nuclear Information System (INIS)

    Schwartz, D.A.; Madejski, G.; Ku, W.H.-M.

    1982-01-01

    As one part of our joint study of the X-ray properties of BL Lac objects, the authors compare the measured X-ray flux densities with those predicted using the synchrotron self-Compton (SSC) formalism (Jones et al. 1974). Naive application of the formalism predicts X-ray fluxes from 10 -3 to 10 5 those observed. They therefore ask what we can learn by simply assuming the SSC mechanism, and looking for ways to reconcile the observed and measured X-ray fluxes. This paper reports investigation of beaming factors due to relativistic ejection of a radiation source which is isotropic in its own rest frame. The authors conclude that large Lorentz factors, GAMMA approximately > 10, do not apply to BL Lac objects as a class. (Auth.)

  11. VLBA Observations of Low Luminosity Flat Spectrum Radio Galaxies and BL Lac Objects: Polarisation Properties

    Science.gov (United States)

    Bondi, M.; Dallacasa, D.; Stanghellini, C.; Marchã, M. J. M.

    We obtained two-epoch VLBA observations at 5 GHz of a list of radio galaxies drawn from the 200 mJy sample (Marcha et al. 1996). The objects selected for milli-arcsecond scale observations are classified, on the basis of their optical spectroscopic and polarimetric properties, as BL Lac objects, normal weak line radio galaxies, broad line radio galaxies, and transition objects (those with intermediate properties). We present preliminary results on the radio polarization properties, on the milli-arcsecond scale, of objects with different optical properties and discuss structural variations detected from the two epochs.

  12. Constraining the red shifts of TeV BL Lac objects

    Science.gov (United States)

    Qin, Longhua; Wang, Jiancheng; Yan, Dahai; Yang, Chuyuan; Yuan, Zunli; Zhou, Ming

    2018-01-01

    We present a model-dependent method to estimate the red shifts of three TeV BL Lac objects (BL Lacs) through fitting their (quasi-)simultaneous multi-waveband spectral energy distributions (SEDs) with a one-zone leptonic synchrotron self-Compton model. Considering the impact of electron energy distributions (EEDs) on the results, we use three types of EEDs to fit the SEDs: a power-law EED with exponential cut-off (PLC), a log-parabola (PLLP) EED and the broken power-law (BPL) EED. We also use a parameter α to describe the uncertainties of the extragalactic background light models, as in Abdo et al. We then use a Markov chain Monte Carlo method to explore the multi-dimensional parameter space and obtain the uncertainties of the model parameters based on the observational data. We apply our method to obtain the red shifts of three TeV BL Lac objects in the marginalized 68 per cent confidence, and find that the PLC EED does not fit the SEDs. For 3C66A, the red shift is 0.14-0.31 and 0.16-0.32 in the BPL and PLLP EEDs. For PKS1424+240, the red shift is 0.55-0.68 and 0.55-0.67 in the BPL and PLLP EEDs. For PG1553+113, the red shift is 0.22-0.48 and 0.22-0.39 in the BPL and PLLP EEDs. We also estimate the red shift of PKS1424+240 in the high stage to be 0.46-0.67 in the PLLP EED, roughly consistent with that in the low stage.

  13. Radio emission from quasars and BL Lac objects by coherent plasma oscillation and stimulated Compton scattering

    International Nuclear Information System (INIS)

    Colgate, S.A.; Petschek, A.G.

    1978-01-01

    The full radiation spectrum of quasars and BL Lac objects is interpreted as due to a dependent combination of a soft plasma oscillation source at 2ν/sub P/ and bremsstrahlung. Previous work of the plasma oscillation radiation is extended into the radio part of the spectrum and it is shown how the high brightness temperature observations of BL Lac objects [kT/sub b/ (100 MHz) approximate = 3 x 10 5 mc 2 ] are a reasonable consequence of a lower external plasma density and ejection as required for the observed lack of emission lines. Two extreme cases are considered, the one where the plasma oscillations are suddenly extinguished and only stimulated Compton scattering remains and a second case of a constant source of plasma oscillations but a graded surface density. The first case gives 1/100 of the required brightness temperature and the second gives 100 times too large a brightness temperature and also a x 10 too large a radius. It is believed reasonable to invoke a combination of both processes to explain the observed radio spectrum. This model circumvents the self-Compton x-ray flux difficulty of incoherent synchrotron emission

  14. 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.

  15. The ultraviolet to X-ray continua of BL Lac objects

    International Nuclear Information System (INIS)

    George, I.M.; Warwick, R.S.; McHardy, I.M.

    1988-01-01

    The results from EXOSAT observations of three X-ray bright BL Lacertae objects, Mrk 501, 1218 + 304 and Mrk 180 are presented. All three sources have soft power-law X-ray spectra with low-energy cut-offs consistent with absorption in the line-of-sight gas column density through our own galaxy. The three objects also exhibit significant spectral variability in the X-ray band on time-scales ranging from a few days to a year. In each case, X-ray flux and spectral index appear to be correlated, in the sense that the X-ray spectrum hardens as the source brightens. The intrinsic ultraviolet to X-ray spectrum of these and several other X-ray bright BL Lac objects can be modelled as a power-law continuum of energy index ∼1.0 below about 0.1 keV, above which the spectral slope steepens. (author)

  16. Spectroscopy of 10 γ -Ray BL Lac Objects at High Redshift

    Energy Technology Data Exchange (ETDEWEB)

    Paiano, Simona; Falomo, Renato [INAF, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Landoni, Marco [INAF, Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (Italy); Treves, Aldo [Università degli Studi dell’Insubria, Via Valleggio 11, I-22100 Como (Italy); Scarpa, Riccardo [Instituto de Astrofisica de Canarias, C/O Via Lactea, s/n E-38205 La Laguna, Tenerife (Spain)

    2017-08-01

    We present optical spectra with high signal-to-noise ratio of 10 BL Lac objects detected at GeV energies by the Fermi satellite (3FGL catalog), which previous observations suggested are at relatively high redshift. The new observations, obtained at the 10 m Gran Telescopio Canarias, allowed us to find the redshift for J0814.5+2943 ( z = 0.703), and we can set a spectroscopic lower limit for J0008.0+4713 ( z > 1.659) and J1107.7+0222 ( z > 1.0735) on the basis of Mg ii intervening absorption features. In addition we confirm the redshifts for J0505.5+0416 ( z = 0.423) and J1450+5200 ( z > 2.470). Finally we contradict the previous z estimates for five objects (J0049.7+0237, J0243.5+7119, J0802.0+1005, J1109.4+2411, and J2116.1+3339).

  17. The UV spectrum of the BL Lac object PKS 0521-36

    International Nuclear Information System (INIS)

    Danziger, I.J.; Bergeron, J.; Maraschi, L.; Treves, A.; Milan Univ.; Tanzi, E.G.

    1983-01-01

    Ultraviolet observations (1200 to 3000 A) with the IUE satellite of the BL Lac object PKS 0521-36 are presented. The only emission line which appears clearly in the spectrum is Lyα, which is asymmetric with a component displaced approx. 3000 km s - 1 to the red. The intensity of the line and the upper limits on other lines are compared with the model calculations on QSOs and Seyfert nuclei by Kwan and Krolik. The continuous energy distribution is discussed, combining non-simultaneous observations from the ultraviolet to the infrared. The spectral range of the non-thermal source from far IR to far UV can be described by a single power law of index -1.5. (author)

  18. UV spectrum of the BL Lac object PKS 0521-36

    Energy Technology Data Exchange (ETDEWEB)

    Danziger, I.J. (European Southern Observatory, Garching (Germany, F.R.)); Bergeron, J. (Centre National de la Recherche Scientifique, 75 - Paris (France). Inst. d' Astrophysique); Fosbury, R.A.E. (Royal Greenwich Observatory, Hailsham (UK)); Maraschi, L.; Treves, A. (Consiglio Nazionale delle Ricerche, Milan (Italy). Lab. di Fisica Cosmica; Milan Univ. (Italy). Ist. di Fisica); Tanzi, E.G. (Consiglio Nazionale delle Ricerche, Milan (Italy). Lab. di Fisica Cosmica)

    1983-05-01

    Ultraviolet observations (1200 to 3000 A) with the IUE satellite of the BL Lac object PKS 0521-36 are presented. The only emission line which appears clearly in the spectrum is Ly..cap alpha.., which is asymmetric with a component displaced approx. 3000 km s/sup -1/ to the red. The intensity of the line and the upper limits on other lines are compared with the model calculations on QSOs and Seyfert nuclei by Kwan and Krolik. The continuous energy distribution is discussed, combining non-simultaneous observations from the ultraviolet to the infrared. The spectral range of the non-thermal source from far IR to far UV can be described by a single power law of index -1.5.

  19. Variable quasi-stellar sources with particular emphasis on objects of the BL Lac type

    International Nuclear Information System (INIS)

    Kinman, T.D.

    1975-01-01

    The optically variable quasars tend to have steep optical spectra and to show variable polarization; they tend to be associated with compact radio sources which have flat radio spectra at GHz frequencies. Objects are known which have continuous spectra (like BL Lac and OJ 287), but whose other properties closely parallel those of the variable quasars and N galaxies; in fact no sharp distinction can be drawn between them. The variation in the visibility of emission lines in quasars and N galaxies could be due to variations in the strength and spectral index of the radiation from the non-thermal source and from the differences in the amount and disposition of the material around it; it does not seem likely that a combination of these factors accounts for the observed range in emission line strength. The systematic difference in optical spectral index between continuous-spectrum objects (and OVV variables) on the one hand and those with emission lines on the other will produce a difference in K term between them, which may be expected to affect their distributions with respect to apparent magnitude. (Auth.)

  20. A Very High Energy Gamma-Ray Spectrum of 1ES 2344+514

    OpenAIRE

    Schroedter, M.; Badran, H. M.; Buckley, J. H.; Gordo, J. Bussons; Carter-Lewis, D. A.; Duke, C.; Fegan, D. J.; Fegan, S. F.; Finley, J. P.; Gillanders, G. H.; Grube, J.; Horan, D.; Kenny, G. E.; Kertzman, M.; Kosack, K.

    2005-01-01

    The BL Lacertae (BL Lac) object 1ES 2344+514 (1ES 2344), at a redshift of 0.044, was discovered as a source of very high energy (VHE) gamma rays by the Whipple Collaboration in 1995 \\citep{2344Catanese98}. This detection was recently confirmed by the HEGRA Collaboration \\citep{2344Hegra03}. As is typical for high-frequency peaked blazars, the VHE gamma-ray emission is highly variable. On the night of 20 December, 1995, a gamma-ray flare of 5.3-sigma significance was detected, the brightest ou...

  1. Quasi-simultaneous observations of BL Lac object Mrk 501 in X-ray, UV, visible, IR, and radio frequencies

    International Nuclear Information System (INIS)

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

    1981-01-01

    Quasi-simultaneous observations of the BL Lac object Mrk 501 were performed for the first time at X-ray, ultraviolet, visible infrared, and radio frequencies. As the BL Lac objects are known to vary in their flux, such a ''quasi-instantaneous'' spectral energy profile is necessary in order to describe properly the energy generation mechanism. The observed spectral slope from the X-ray to UV regions is positive and continuous, but that from the mid-UV to visible light region becomes gradually flat and possibly turns down toward lower frequencies; the optical-radio emission cannot be accounted for by a single power law. Several theoretical models have been considered for the emission mechanism. In some cases quantitative comparison with the data is not practical. However, most of the models are, at least, not inconsistent with the observations. A quantitative comparison has been peformed with the synchroton self-Compton model; the total spectrum is found consistent with this model. The spectrum from visible light to X-ray is consistent with synchrotron radiation or with inverse-Compton scattering by a hot thermal cloud of electrons. The continuity of the spectral slope from X-ray to UV implied by the current data suggests that the previous estimates of the total luminosity of this BL Lac object has been underestimated by a factor of about 3 or 4

  2. 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.

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

    Indian Academy of Sciences (India)

    obtain statistically meaningful values for the cross-correlation time lags ... deviation, the fifth represents the largest variations, the sixth represents the fractional ..... 6. Conclusions. The multi-band optical data are collected on the object of AO 0235 + 164. The time lags among the B, V, R and I bands have been analysed.

  4. Using the Markov chain Monte Carlo method to study the physical properties of GeV-TeV BL Lac objects

    Science.gov (United States)

    Qin, Longhua; Wang, Jiancheng; Yang, Chuyuan; Yuan, Zunli; Mao, Jirong; Kang, Shiju

    2018-01-01

    We fit the spectral energy distributions (SEDs) of 46 GeV-TeV BL Lac objects in the frame of leptonic one-zone synchrotron self-Compton (SSC) model and investigate the physical properties of these objects. We use the Markov chain Monte Carlo (MCMC) method to obtain the basic parameters, such as magnetic field (B), the break energy of the relativistic electron distribution (γ ^' }b), and the electron energy spectral index. Based on the modeling results, we support the following scenarios for GeV-TeV BL Lac objects. (1) Some sources have large Doppler factors, implying other radiation mechanism should be considered. (2) Compared with flat spectrum quasars (FSRQs), GeV-TeV BL Lac objects have weaker magnetic fields and larger Doppler factors, which cause the ineffective cooling and shift the SEDs to higher bands. Their jet powers are around 4.0 × 1045 erg s-1, compared with radiation power, 5.0 × 1042 erg s-1, indicating that only a small fraction of jet power is transformed into the emission power. (3) For some BL Lacs with large Doppler factors, their jet components could have two substructures, e.g., the fast core and the slow sheath. For most GeV-TeV BL Lacs, Kelvin-Helmholtz instabilities are suppressed by their higher magnetic fields, leading to micro-variability or intro-day variability in the optical bands. (4) Combined with a sample of FSRQs, an anti-correlation between the peak luminosity, Lpk, and the peak frequency, νpk, is obtained, favoring the blazar sequence scenario. In addition, an anti-correlation between the jet power, Pjet, and the break Lorentz factor, γb, also supports the blazar sequence.

  5. Quasi-simultaneous observations of BL Lac object Mrk 501 in X-ray, UV, visible, IR, and radio frequencies

    Science.gov (United States)

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

    1981-01-01

    Observations in the X-ray, UV, visible, IR and radio regions of the BL Lac object Mrk 501 made over the course of two months are reported. The measurements were made with the A2 experiment on HEAO 1 (X-ray), the SWP and LWR cameras on IUE (UV), the 5-m Hale telescope (visible), the 2.5-m telescope at Mount Wilson (IR), the NRAO 92-m radio telescope at Green Bank (4750 MHz) and the 46-m radio telescope at the Algonquin Observatory (10275 and 10650 MHz). The quasi-simultaneously observed spectral slope is found to be positive and continuous from the X-ray to the UV, but to gradually flatten and possibly turn down from the mid-UV to the visible; the optical-radio emission cannot be accounted for by a single power law. The total spectrum is shown to be compatible with a synchrotron self-Compton emission mechanism, while the spectrum from the visible to the X-ray is consistent with synchrotron radiation or inverse-Compton scattering by a hot thermal electron cloud. The continuity of the spectrum from the UV to the X-ray is noted to imply a total luminosity greater than previous estimates by a factor of 3-4.

  6. Multiwavelength Variability Study of the Classical BL Lac Object PKS 0735+178 on Timescales Ranging from Decades to Minutes

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, Arti; Stawarz, Łukasz; Ostrowski, Michał; Soida, Marian [Astronomical Observatory of Jagiellonian University, ul. Orla 171, 30-244 Kraków (Poland); Larionov, Valeri [Astronomical Institute of St. Petersburg State University, Petrodvorets 198504 (Russian Federation); Gopal-Krishna [Centre for Excellence in Basic Sciences (CEBS), University of Mumbai campus (Kalina), Mumbai 400098 (India); Wiita, Paul J. [Department of Physics, The College of New Jersey, 2000 Pennington Road, Ewing, NJ 08628-0718 (United States); Joshi, Santosh [Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital 263002 (India); Agudo, Iván, E-mail: arti@oa.uj.edu.pl [Instituto de Astrofísica de Andalucía (CSIC), Apartado 3004, E–18080 Granada (Spain)

    2017-03-10

    We present the results of our power spectral analysis for the BL Lac object PKS 0735+178, utilizing the Fermi -LAT survey at high-energy γ -rays, several ground-based optical telescopes, and single-dish radio telescopes operating at GHz frequencies. The novelty of our approach is that, by combining long-term and densely sampled intra-night light curves in the optical regime, we were able to construct for the first time the optical power spectrum of the blazar for a time domain extending from 23 years down to minutes. Our analysis reveals that: (1) the optical variability is consistent with a pure red noise, for which the power spectral density can be well approximated by a single power law throughout the entire time domain probed; (2) the slope of power spectral density at high-energy γ -rays (∼1) is significantly flatter than that found at radio and optical frequencies (∼2) within the corresponding time variability range; (3) for the derived power spectra, we did not detect any low-frequency flattening, nor do we see any evidence for cutoffs at the highest frequencies down to the noise floor levels due to measurement uncertainties. We interpret our findings in terms of a model where the blazar variability is generated by the underlying single stochastic process (at radio and optical frequencies), or a linear superposition of such processes (in the γ -ray regime). Along with the detailed PSD analysis, we also present the results of our extended (1998–2015) intra-night optical monitoring program and newly acquired optical photo-polarimetric data for the source.

  7. Jet Precession Driven by a Supermassive Black Hole Binary System in the BL Lac Object PG 1553+113

    Science.gov (United States)

    Caproni, Anderson; Abraham, Zulema; Motter, Juliana Cristina; Monteiro, Hektor

    2017-12-01

    The recent discovery of a roughly simultaneous periodic variability in the light curves of the BL Lac object PG 1553+113 at several electromagnetic bands represents the first case of such odd behavior reported in the literature. Motivated by this, we analyzed 15 GHz interferometric maps of the parsec-scale radio jet of PG 1553+113 to verify the presence of a possible counterpart of this periodic variability. We used the Cross-entropy statistical technique to obtain the structural parameters of the Gaussian components present in the radio maps of this source. We kinematically identified seven jet components formed coincidentally with flare-like features seen in the γ-ray light curve. From the derived jet component positions in the sky plane and their kinematics (ejection epochs, proper motions, and sky position angles), we modeled their temporal changes in terms of a relativistic jet that is steadily precessing in time. Our results indicate a precession period in the observer’s reference frame of 2.24 ± 0.03 years, compatible with the periodicity detected in the light curves of PG 1553+113. However, the maxima of the jet Doppler boosting factor are systematically delayed relative to the peaks of the main γ-ray flares. We propose two scenarios that could explain this delay, both based on the existence of a supermassive black hole binary system in PG 1553+113. We estimated the characteristics of this putative binary system that also would be responsible for driving the inferred jet precession.

  8. Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C 273 from 2000 to 2014

    Science.gov (United States)

    Yuan, Yu-Hai; Fan, Jun-hui; Tao, Jun; Qian, Bo-Chen; Costantin, Denise; Xiao, Hu-Bing; Pei, Zhi-Yuan; Lin, Chao

    2017-09-01

    Context. Using the 1.56 m telescope at the Shanghai Observatory (ShAO), China, we monitored two sources, BL Lac object S5 0716+714 and flat spectrum radio quasar (FSRQ) 3C 273. For S5 0716+714, we report 4969 sets of CCD (Charge-coupled Device) photometrical optical observations (1369 for V band, 1861 for R band and 1739 for I band) in the monitoring time from Dec. 4, 2000 to Apr. 5, 2014. For 3C 273, we report 460 observations (138 for V band, 146 for R band and 176 for I band) in the monitoring time from Mar. 28, 2006 to Apr. 9, 2014. Aims: The observations provide us with a large amount of data to analyze the short-term and long-term optical variabilities. Based on the variable timescales, we can estimate the central black hole mass and the Doppler factor. An abundance of multi-band observations can help us to analyze the relations between the brightness and spectrum. Methods: We use Gaussian fitting to analyze the intra-day light curves and obtain the intra-day variability (IDV) timescales. We use the discrete correlation function (DCF) method and Jurkevich method to analyze the quasi-periodic variability. Based on the VRI observations, we use the linear fitting to analyze the relations between brightness and spectrum. Results: The two sources both show IDV properties for S5 0716+714. The timescales are in the range from 17.3 min to 4.82 h; for 3C 273, the timescale is ΔT = 35.6 min. Based on the periodic analysis methods, we find the periods PV = 24.24 ± 1.09 days, PR = 24.12 ± 0.76 days, PI = 24.82 ± 0.73 days for S5 0716+714, and P = 12.99 ± 0.72, 21.76 ± 1.45 yr for 3C 273. The two sources displayed the "bluer-when-brighter" spectral evolution properties. Conclusions: S5 0716+714 and 3C 273 are frequently studied objects. The violent optical variability and IDV may come from the jet. Gaussian fitting can be used to analyze IDVs. The relations between brightness (flux density) and spectrum are strongly influenced by the frequency. A table of the

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

    Science.gov (United States)

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

    1980-01-01

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

  10. ASCA and Contemporaneous Ground-based Observations of the BL Lacertae Objects 1749+096 and 2200+420 (BL Lac)

    International Nuclear Information System (INIS)

    Sambruna, R.M.; Ghisellini, G.; Hooper, E.; Kollgaard, R.I.; Pesce, J.E.; Urry, C.M.

    1999-01-01

    We present ASCA observations of the radio-selected BL Lacertae objects 1749+096 (z=0.32) and 2200+420 (BL Lac, z=0.069) performed in 1995 September and November, respectively. The ASCA spectra of both sources can be described as a first approximation by a power law with photon index Γ∼2. This is flatter than for most X-ray endash selected BL Lacs observed with ASCA, in agreement with the predictions of current blazar unification models. While 1749+096 exhibits tentative evidence for spectral flattening at low energies, a concave continuum is detected for 2200+420: the steep low-energy component is consistent with the high-energy tail of the synchrotron emission responsible for the longer wavelengths, while the harder tail at higher energies is the onset of the Compton component. The two BL Lacs were observed with ground-based telescopes from radio to TeV energies contemporaneously with ASCA. The spectral energy distributions are consistent with synchrotron self-Compton emission from a single homogeneous region shortward of the IR/optical wavelengths, with a second component in the radio domain related to a more extended emission region. For 2200+420, comparing the 1995 November state with the optical/GeV flare of 1997 July, we find that models requiring inverse Compton scattering of external photons provide a viable mechanism for the production of the highest (GeV) energies during the flare. In particular, an increase of the external radiation density and of the power injected in the jet can reproduce the flat γ-ray continuum observed in 1997 July. A directly testable prediction of this model is that the line luminosity in 2200+420 should vary shortly after (∼1 month) a nonthermal synchrotron flare. copyright copyright 1999. The American Astronomical Society

  11. A Search for Quasi-periodic Oscillations in the Blazar 1ES 1959+650

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiao-Pan; Luo, Yu-Hui; Yang, Hai-Yan; Cai, Yan; Yang, Hai-Tao [Department of Physics, Zhaotong University, Zhaotong, 657000 (China); Yang, Cheng, E-mail: lxpzrc@163.com [College of Photoelectron and Communication Engineering, Yunnan Open University, Kunming, 650223 (China)

    2017-09-20

    We have searched quasi-periodic oscillations (QPOs) in the 15 GHz light curve of the BL Lac object 1ES 1959+650 monitored by the Owens Valley Radio Observatory 40 m telescope during the period from 2008 January to 2016 February, using the Lomb–Scargle Periodogram, power spectral density (PSD), discrete autocorrelation function, and phase dispersion minimization (PDM) techniques. The red noise background has been established via the PSD method, and no QPO can be derived at the 3 σ confidence level accounting for the impact of the red noise variability. We conclude that the light curve of 1ES 1959+650 can be explained by a stochastic red noise process that contributes greatly to the total observed variability amplitude, dominates the power spectrum, causes spurious bumps and wiggles in the autocorrelation function and can result in the variance of the folded light curve decreasing toward lower temporal frequencies when few-cycle, sinusoid-like patterns are present. Moreover, many early supposed periodicity claims for blazar light curves need to be reevaluated assuming red noise.

  12. Redshift determination of the BL Lac object 3C 66A by the detection of its host galaxy cluster at z = 0.340

    Science.gov (United States)

    Torres-Zafra, Juanita; Cellone, Sergio A.; Buzzoni, Alberto; Andruchow, Ileana; Portilla, José G.

    2018-03-01

    The BL Lac object 3C 66A is one of the most luminous extragalactic sources at TeV γ-rays (very high energy, i.e. E > 100 GeV). Since TeV γ-ray radiation is absorbed by the extragalactic background light (EBL), it is crucial to know the redshift of the source in order to reconstruct its original spectral energy distribution, as well as to constrain EBL models. However, the optical spectrum of this BL Lac is almost featureless, so a direct measurement of z is very difficult; in fact, the published redshift value for this source (z = 0.444) has been strongly questioned. Based on EBL absorption arguments, several constraints to its redshift, in the range 0.096 GMOS-N multi-object spectroscopy. We found spectroscopic evidence of two galaxy groups along the blazar's line of sight: one at z ≃ 0.020 and the second one at z ≃ 0.340. The first one is consistent with a known foreground structure, while the second group presented here has six spectroscopically confirmed members. Their location along a red sequence in the colour-magnitude diagram allows us to identify 34 additional candidate members of the more distant group. The blazar's spectrum shows broad absorption features that we identify as arising in the intergalactic medium, thus allowing us to tentatively set a redshift lower limit at z_3C66A ≳ 0.33. As a consequence, we propose that 3C 66A is hosted in a galaxy that belongs to a cluster at z = 0.340.

  13. Energy distribution and variability of BL Lac objects. The cases of PKS 2155-304 and 3C 66A

    International Nuclear Information System (INIS)

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

    1983-01-01

    The BL Lacertae objects, PKS 2155-304 and 3C66A have been observed in the ultraviolet and the X-ray region. The radiation flux in both regions are discussed with respect to its energy and time dependence. (Auth.)

  14. Lac dayet Aoua (Maroc)

    African Journals Online (AJOL)

    Saad

    F.S.T. Fès - Sais, Université Sidi Mohammed Abdallah Fès, B.P. 2202, Maroc. 2Laboratoire des ... d'étude en complément de la composition phytoplanctonique et des analyses de la physico-chimie des eaux à l'entrée, au ... L'analyse des paramètres physico-chimiques, au point central du lac, a montré que l'eau du lac.

  15. Indian Americans at Mille Lacs.

    Science.gov (United States)

    Holbert, Victoria L.; And Others

    The Training Center for Community Programs prepared a report on the Mille Lacs (Chippewa) Reservation in Minnesota. Data for the report were from 2 separate sources: a survey conducted by the Training Center with the assistance of the Mille Lacs community action program (1967) and an attitudinal survey conducted by Victoria Holbert during 1969.…

  16. The Discovery of Low-Luminosity BL Lacs

    Science.gov (United States)

    Rector, Travis A.; Stocke, John T.

    1995-12-01

    Many of the properties of BL Lacs have become explicable in terms of the ``relativistic beaming'' hypothesis whereby BL Lacs are ``highly beamed'' FR-I radio galaxies (i.e. our line of sight to these objects is nearly along the jet axis). Further, radio-selected BL Lacs (RBLs) are believed to be seen nearly ``on-axis'' (the line-of-sight angle theta ~ 8deg ) while X-ray selected BL Lacs (XBLs) are seen at larger angles (theta ~ 30deg ; the X-ray emitting jet is believed to be less collimated). However, a major problem with this model was that a transition population between beamed BL Lacs and unbeamed FR-Is had not been detected. Low-luminosity BL Lacs may be such a transition population, and were predicted to exist by Browne and Marcha (1993). We present ROSAT HRI images, VLA radio maps and optical spectra which confirm the existence of low-luminosity BL Lacs, objects which were previously mis-identified in the EMSS catalog as clusters of galaxies. Thus our results strengthen the relativistic beaming hypothesis.

  17. Flat radio-spectrum galaxies and BL Lacs I. Core properties

    NARCIS (Netherlands)

    Dennett-Thorpe, J; Marcha, MJ

    This paper concerns the relationship of BL Lacs and flat-spectrum weak emission-line galaxies. We compare the weak emission-line galaxies and the BL Lacs in a sample of 57 flat-spectrum objects (Marcha et al. 1996), using high-frequency radio and non-thermal optical flux densities, spectral indices

  18. The REX survey as a Tool to Test the Beaming Model for BL Lacs

    Science.gov (United States)

    Caccianiga, A.; della Ceca, R.; Gioia, I. M.; Maccacaro, T.; Wolter, A.

    We present the preliminary properties of the BL Lacs discovered in the REX survey (Caccianiga et al. 1998). In particular, we discuss a few sources with optical spectral properties ``intermediate'' between those of BL Lacs and those of elliptical galaxies. These objects could harbour weak (in the optical band) sources of non-thermal continuum in their nuclei and, if confirmed, they could represent the faint tail of the BL Lac population. The existence of such ``weak'' BL Lacs is matter of discussion in recent literature (e.g. Marcha et al. 1996) and could lead to a revision of the defining criteria of a BL Lac and, consequently, of their cosmological and statistical properties.

  19. The Radio-optical Spectra of BL Lacs and Possible Relatives

    Science.gov (United States)

    Dennett-Thorpe, J.

    I consider the suggestion that, in a complete sample of flat-spectrum radio sources with available optical spectra (Marcha et al 1996), the strong emission line objects, or those with passive elliptical spectra are close relatives of the BL Lacs. New observations at four frequencies from 8 to 43GHz are presented, together with evidence for radio variability. Combined with other radio and optical data from the literature, we are able to construct the non-thermal SEDs and use these to address the questions: are the optically passive objects potentially `unrecognised' BL Lacs (either intrinsically weak and/or hidden by starlight)? What is the relationship between the surprising number of strong emission-line objects and the BL Lacs?

  20. The comparison between LAC and ALA

    Directory of Open Access Journals (Sweden)

    Tzu-heng Chiu

    2000-12-01

    Full Text Available A good library association serves its members, improves the librarianship, and helps library institutions achieving their missions. This article describes the history, missions and goals, organization structure, membership, financial sources, professional activities, publication, and website of the Library Association of China (LAC and American Library Association (ALA, respectively. Considering social / cultural / political differences between Taiwan and the United Sates, the author then compares these two library associations from the eight factors mentioned above. At the end, suggestions for the LAC are proposed.[Article content in Chinese

  1. CLUSTERING OF γ-RAY-SELECTED 2LAC FERMI BLAZARS

    Energy Technology Data Exchange (ETDEWEB)

    Allevato, V.; Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki (Finland); Cappelluti, N. [University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

    2014-12-20

    We present the first measurement of the projected correlation function of 485 γ-ray-selected blazars, divided into 175 BL Lacertae (BL Lacs) and 310 flat-spectrum radio quasars (FSRQs) detected in the 2 year all-sky survey by the Fermi-Large Area Telescope. We find that Fermi BL Lacs and FSRQs reside in massive dark matter halos (DMHs) with log M{sub h} = 13.35{sub −0.14}{sup +0.20} and log M{sub h} = 13.40{sub −0.19}{sup +0.15} h {sup –1} M {sub ☉}, respectively, at low (z ∼ 0.4) and high (z ∼ 1.2) redshift. In terms of clustering properties, these results suggest that BL Lacs and FSRQs are similar objects residing in the same dense environment typical of galaxy groups, despite their different spectral energy distributions, power, and accretion rates. We find no difference in the typical bias and hosting halo mass between Fermi blazars and radio-loud active galactic nuclei (AGNs), supporting the unification scheme simply equating radio-loud objects with misaligned blazar counterparts. This similarity in terms of the typical environment they preferentially live in, suggests that blazars tend to occupy the center of DMHs, as already pointed out for radio-loud AGNs. This implies, in light of several projects looking for the γ-ray emission from DM annihilation in galaxy clusters, a strong contamination from blazars to the expected signal from DM annihilation.

  2. Natural LacI from E. coli Yields Faster Response and Higher Level of Expression than the LVA-Tagged LacI

    DEFF Research Database (Denmark)

    Andreassen, Patrick Rosendahl; Fredberg, Sofie; Horan, Mattias

    2014-01-01

    The lac promoter is one of the most commonly used promoters for expression control of recombinant genes in E. coli. In the absence of galactosides, the lac promoter is repressed by its repressor protein LacI. Since the lac promoter is regulated by a repressor, overexpression of LacI is necessary...

  3. The Sedentary Multi-Frequency Survey. I. Statistical Identification and Cosmological Properties of HBL BL Lacs

    OpenAIRE

    Giommi, P.; Menna, M. T.; Padovani, P.

    1999-01-01

    We have assembled a multi-frequency database by cross-correlating the NVSS catalog of radio sources with the RASSBSC list of soft X-ray sources, obtaining optical magnitude estimates from the Palomar and UK Schmidt surveys as provided by the APM and COSMOS on-line services. By exploiting the nearly unique broad-band properties of High-Energy Peaked (HBL) BL Lacs we have statistically identified a sample of 218 objects that is expected to include about 85% of BL Lacs and that is therefore seve...

  4. Objectivity

    CERN Document Server

    Daston, Lorraine

    2010-01-01

    Objectivity has a history, and it is full of surprises. In Objectivity, Lorraine Daston and Peter Galison chart the emergence of objectivity in the mid-nineteenth-century sciences--and show how the concept differs from its alternatives, truth-to-nature and trained judgment. This is a story of lofty epistemic ideals fused with workaday practices in the making of scientific images. From the eighteenth through the early twenty-first centuries, the images that reveal the deepest commitments of the empirical sciences--from anatomy to crystallography--are those featured in scientific atlases, the compendia that teach practitioners what is worth looking at and how to look at it. Galison and Daston use atlas images to uncover a hidden history of scientific objectivity and its rivals. Whether an atlas maker idealizes an image to capture the essentials in the name of truth-to-nature or refuses to erase even the most incidental detail in the name of objectivity or highlights patterns in the name of trained judgment is a...

  5. A Search for Low-Luminosity BL Lacertae Objects

    Science.gov (United States)

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

    1999-05-01

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

  6. γ-Ray Emission from the Extreme Blazar 1ES 0229+200 J. Li, T ...

    Indian Academy of Sciences (India)

    Abstract. Based on the traditional Synchrotron Self-Compton (SSC) model, we consider a secondary γ-ray emission component to an extreme blazar 1ES 0229 + 200 for the multiwavelength radiation. By assuming a suitable electron spectra and Inter-Galactic Magnetic Field (IGMF), we obtained excellent fits to observed ...

  7. PROBING THE TRANSITION BETWEEN THE SYNCHROTRON AND INVERSE-COMPTON SPECTRAL COMPONENTS OF 1ES 1959+650

    International Nuclear Information System (INIS)

    Bottacini, E.; Schady, P.; Rau, A.; Zhang, X.-L.; Greiner, J.; Boettcher, M.; Ajello, M.; Fendt, C.

    2010-01-01

    1ES 1959+650 is one of the most remarkable high-peaked BL Lacertae objects (HBL). In 2002, it exhibited a TeV γ-ray flare without a similar brightening of the synchrotron component at lower energies. This orphan TeV flare remained a mystery. We present the results of a multifrequency campaign, triggered by the INTEGRAL IBIS detection of 1ES 1959+650. Our data range from the optical to hard X-ray energies, thus covering the synchrotron and inverse-Compton components simultaneously. We observed the source with INTEGRAL, the Swift X-Ray Telescope, and the UV-Optical Telescope, and nearly simultaneously with a ground-based optical telescope. The steep spectral component at X-ray energies is most likely due to synchrotron emission, while at soft γ-ray energies the hard spectral index may be interpreted as the onset of the high-energy component of the blazar spectral energy distribution (SED). This is the first clear measurement of a concave X-ray-soft γ-ray spectrum for an HBL. The SED can be well modeled with a leptonic synchrotron self-Compton model. When the SED is fitted this model requires a very hard electron spectral index of q ∼ 1.85, possibly indicating the relevance of second-order Fermi acceleration.

  8. Structure-guided approach to site-specific fluorophore labeling of the lac repressor LacI.

    Directory of Open Access Journals (Sweden)

    Kalle Kipper

    Full Text Available The lactose operon repressor protein LacI has long served as a paradigm of the bacterial transcription factors. However, the mechanisms whereby LacI rapidly locates its cognate binding site on the bacterial chromosome are still elusive. Single-molecule fluorescence imaging approaches are well suited for the study of these mechanisms but rely on a functionally compatible fluorescence labeling of LacI. Particularly attractive for protein fluorescence labeling are synthetic fluorophores due to their small size and favorable photophysical characteristics. Synthetic fluorophores are often conjugated to natively occurring cysteine residues using maleimide chemistry. For a site-specific and functionally compatible labeling with maleimide fluorophores, the target protein often needs to be redesigned to remove unwanted native cysteines and to introduce cysteines at locations better suited for fluorophore attachment. Biochemical screens can then be employed to probe for the functional activity of the redesigned protein both before and after dye labeling. Here, we report a mutagenesis-based redesign of LacI to enable a functionally compatible labeling with maleimide fluorophores. To provide an easily accessible labeling site in LacI, we introduced a single cysteine residue at position 28 in the DNA-binding headpiece of LacI and replaced two native cysteines with alanines where derivatization with bulky substituents is known to compromise the protein's activity. We find that the redesigned LacI retains a robust activity in vitro and in vivo, provided that the third native cysteine at position 281 is retained in LacI. In a total internal reflection microscopy assay, we observed individual Cy3-labeled LacI molecules bound to immobilized DNA harboring the cognate O1 operator sequence, indicating that the dye-labeled LacI is functionally active. We have thus been able to generate a functional fluorescently labeled LacI that can be used to unravel mechanistic

  9. Opening Up Natural Resource Based Industries for Innovation (LAC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Opening Up Natural Resource Based Industries for Innovation (LAC). Commodities based on natural resources account for at least half of the exports of two-thirds of the countries in Latin America and the Caribbean (LAC). There is growing concern, however, that existing natural resource-based industries are ...

  10. Baseline surveys of Lac Bay benthic and fish communities, Bonaire

    NARCIS (Netherlands)

    Debrot, A.O.; Hylkema, A.; Vogelaar, W.; Meesters, H.W.G.; Engel, M.S.; Leon, R.; Prud'homme van Reine, W.F.; Nagelkerken, I.

    2012-01-01

    Lac Bay is a clear-water, 5 m deep shallow tropical lagoon of 7 km2 opening onto the wave and wind exposed east coast of the island of Bonaire, southern Caribbean. Over the last decades land reclamation by mangroves in Lac has been expanding the surface of turbid, saline backwaters into the bay at

  11. VizieR Online Data Catalog: The CLASS BL Lac sample (Marcha+, 2013)

    Science.gov (United States)

    Marcha, M. J. M.; Caccianiga, A.

    2014-04-01

    This paper presents a new sample of BL Lac objects selected from a deep (30mJy) radio survey of flat spectrum radio sources (the CLASS blazar survey). The sample is one of the largest well-defined samples in the low-power regime with a total of 130 sources of which 55 satisfy the 'classical' optical BL Lac selection criteria, and the rest have indistinguishable radio properties. The primary goal of this study is to establish the radio luminosity function (RLF) on firm statistical ground at low radio luminosities where previous samples have not been able to investigate. The gain of taking a peek at lower powers is the possibility to search for the flattening of the luminosity function which is a feature predicted by the beaming model but which has remained elusive to observational confirmation. In this study, we extend for the first time the BL Lac RLF down to very low radio powers ~1022W/Hz, i.e. two orders of magnitude below the RLF currently available in the literature. In the process, we confirm the importance of adopting a broader, and more physically meaningful set of classification criteria to avoid the systematic missing of low-luminosity BL Lacs. Thanks to the good statistics we confirm the existence of weak but significant positive cosmological evolution for the BL Lac population, and we detect, for the first time the flattening of the RLF at L~1025W/Hz in agreement with the predictions of the beaming model. (1 data file).

  12. Adsorption Properties of Lac Dyes on Wool, Silk, and Nylon

    Directory of Open Access Journals (Sweden)

    Bo Wei

    2013-01-01

    Full Text Available There has been growing interest in the dyeing of textiles with natural dyes. The research about the adsorption properties of natural dyes can help to understand their adsorption mechanism and to control their dyeing process. This study is concerned with the kinetics and isotherms of adsorption of lac dyes on wool, silk, and nylon fibers. It was found that the adsorption kinetics of lac dyes on the three fibers followed the pseudosecond-order kinetic model, and the adsorption rate of lac dyes was the fastest for silk and the slowest for wool. The activation energies for the adsorption process on wool, silk, and nylon were found to be 107.15, 87.85, and 45.31 kJ/mol, respectively. The adsorption of lac dyes on the three fibers followed the Langmuir mechanism, indicating that the electrostatic interactions between lac dyes and those fibers occurred. The saturation values for lac adsorption on the three fibers decreased in the order of wool > silk > nylon; the Langmuir affinity constant of lac adsorption on nylon was much higher than those on wool and silk.

  13. 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 ...

  14. Photohadronic scenario in interpreting the February-March 2014 flare of 1ES 1011+496

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Sarira [Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, Circuito Exterior, Mexico (Mexico); RIKEN, Astrophysical Big Bang Laboratory, Wako, Saitama (Japan); Rosales de Leon, Alberto [Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, Circuito Exterior, Mexico (Mexico); Salvador Miranda, Luis [University of Johannesburg, Department of Physics, Auckland Park (South Africa)

    2017-11-15

    The extraordinary multi-TeV flare from 1ES 1011+496 during February-March 2014 was observed by the MAGIC telescopes for 17 nights and the average spectrum of the whole period has a non-trivial shape. We have used the photohadronic model and a template extragalactic background light model to explain the average spectrum which fits the flare data well. The spectral index α is the only free parameter in our model. We have also shown that the non-trivial nature of the spectrum is due to the change in the behavior of the optical depth above ∝ 600 GeV γ-ray energy accompanied with the high SSC flux. This corresponds to an almost flat intrinsic flux for the multi-TeV γ-rays. Our model prediction can constrain the SSC flux of the leptonic models in the quiescent state. (orig.)

  15. Photohadronic scenario in interpreting the February-March 2014 flare of 1ES 1011+496

    Science.gov (United States)

    Sahu, Sarira; de León, Alberto Rosales; Miranda, Luis Salvador

    2017-11-01

    The extraordinary multi-TeV flare from 1ES 1011+496 during February-March 2014 was observed by the MAGIC telescopes for 17 nights and the average spectrum of the whole period has a non-trivial shape. We have used the photohadronic model and a template extragalactic background light model to explain the average spectrum which fits the flare data well. The spectral index α is the only free parameter in our model. We have also shown that the non-trivial nature of the spectrum is due to the change in the behavior of the optical depth above ˜ 600 GeV γ -ray energy accompanied with the high SSC flux. This corresponds to an almost flat intrinsic flux for the multi-TeV γ -rays. Our model prediction can constrain the SSC flux of the leptonic models in the quiescent state.

  16. BL Lacertae objects

    International Nuclear Information System (INIS)

    Miller, J.S.

    1978-01-01

    An overview is given of the principal characteristics and problems associated with the prototype BL Lacertae. The most important characteristics of this group and its relevance, the consideration of a few particular objects in moderate detail, the relation between these objects QSOs, and normal galaxies, and finally the possible physical nature of BL Lac objects and the important questions they raise are treated. 15 references

  17. The use of lac-type promoters in control analysis

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Westerhoff, H. v.; Michelsen, Ole

    1993-01-01

    experimentally by constructing E. coli strains, in which the chromosomal atp operon is transcribed from the lacUV5 and the tacI promoter. We measured the concentration of the c subunit of H+-ATPase, and found that the expression of this enzyme could be modulated between non-detectable levels and up to five times...... the wild-type level. Thus, in the absence of inducer, no expression of atp genes could be detected when the atp operon was controlled by the lacUV5 promoter, and we estimate that the expression was less than 0.0025 times the wild-type level. We show that the introduction of a lac Y mutation facilitated...

  18. Dynamic model of gene regulation for the lac operon

    Energy Technology Data Exchange (ETDEWEB)

    Angelova, Maia; Ben-Halim, Asma, E-mail: maia.angelova@northumbria.ac.uk, E-mail: asma.benhalim@northumbria.ac.uk [Intelligent Modelling Lab, School of Computing, Engineering and Information Sciences, Northumbria University, Newcastle upon Tyne NE2 1XE (United Kingdom)

    2011-03-01

    Gene regulatory network is a collection of DNA which interact with each other and with other matter in the cell. The lac operon is an example of a relatively simple genetic network and is one of the best-studied structures in the Escherichia coli bacteria. In this work we consider a deterministic model of the lac operon with a noise term, representing the stochastic nature of the regulation. The model is written in terms of a system of simultaneous first order differential equations with delays. We investigate an analytical and numerical solution and analyse the range of values for the parameters corresponding to a stable solution.

  19. Dynamic model of gene regulation for the lac operon

    International Nuclear Information System (INIS)

    Angelova, Maia; Ben-Halim, Asma

    2011-01-01

    Gene regulatory network is a collection of DNA which interact with each other and with other matter in the cell. The lac operon is an example of a relatively simple genetic network and is one of the best-studied structures in the Escherichia coli bacteria. In this work we consider a deterministic model of the lac operon with a noise term, representing the stochastic nature of the regulation. The model is written in terms of a system of simultaneous first order differential equations with delays. We investigate an analytical and numerical solution and analyse the range of values for the parameters corresponding to a stable solution.

  20. In vivo expression of the lacY gene in two segments leads to functional lac permease

    International Nuclear Information System (INIS)

    Bibi, E.; Kaback, H.R.

    1990-01-01

    The lacY gene of Escherichia coli was cut into two approximately equal-size fragments with Afl II and subcloned individually or together under separate lac operator/promoters in plasmid pT7-5. Under these conditions, lac permease is expressed in two portions: (i) the N-terminal portion (the N terminus, the first six putative transmembrane helices, and most of putative loop 7) and (ii) the C-terminal portion (the last six putative transmembrane helices and the C terminus). Cells harboring pT7-5 encoding both fragments transport lactose at about 30% the rate of cells expressing intact permease to a comparable steady-state level of accumulation. In contrast, cells expressing either half of the permease independently do not transport lactose. As judged by [ 35 S]methionine labeling and immunoblotting, intact permease in completely absent from the membrane of cells expressing lacY fragments either individually or together. Thus, transport activity must result from an association between independently synthesized pieces of lac permease. When the gene fragments are expressed individually, the N-terminal portion of the permease is observed inconsistently, and the C-terminal portion is not observed. When the gene fragments are expressed together, polypeptides identified as the N- and C-terminal moieties of the permease are found in the membrane. It is concluded that the N- or C-terminal halves of lac permease are proteolyzed when synthesized independently and that association between the two complementing polypeptides leads to a more stable, catalytically active complex

  1. Role of radiation therapy in bladder cancer in the Saguenay-Lac Saint-Jean area

    International Nuclear Information System (INIS)

    Brochet, F.; Barrette, L.R.

    1998-01-01

    Bladder cancer is more frequent in Quebec, especially in Saguenay-Lac Saint-Jean than in other Canadian provinces and in the USA. From 1983 to 1996, only 78 patients presenting with bladder cancer received external beam radiation therapy. Sixty-eight were treated with curative intent Overall survival rates were 70% at 3 years, 66% at 5 years, and 40% at 10 years. Retrospective analysis of these cases and literature review show that preoperative radiation therapy is useful in the management of bladder cancer, especially in T3 tumors. It is also useful for patients whose tumor objectively responds to radiation therapy, without an increase in morbidity. (authors)

  2. Lac du Flambeau Band of Lake Superior Chippewa Indians Strategic Energy Plan

    Energy Technology Data Exchange (ETDEWEB)

    Bryan Hoover

    2009-11-16

    This plan discusses the current energy use on the Lac du Flambeau Reservation, the current status of the Tribe's energy program, as well as the issues and concerns with energy on the reservation. This plan also identifies and outlines energy opportunities, goals, and objectives for the Tribe to accomplish. The overall goal of this plan is to address the energy situation of the reservation in a holistic manner for the maximum benefit to the Tribe. This plan is an evolving document that will be re-evaluated as the Tribe's energy situation changes.

  3. Evidence for an intermediate conformational state of LacY.

    Science.gov (United States)

    Jiang, Xiaoxu; Guan, Lan; Zhou, Yonggang; Hong, Wen-Xu; Zhang, Qinghai; Kaback, H Ronald

    2012-03-20

    LacY mutant Cys154 → Gly exhibits a periplasmic-closed crystal structure identical to the WT, but is periplasmic-open in the membrane. The mutant hardly catalyzes transport, but binds galactosides from either side of the membrane with the same affinity and is resistant to site-directed proteolysis relative to the pseudo-WT. Site-directed alkylation was also applied to 11 single-Cys mutants in Cys154 → Gly LacY in right-side-out membrane vesicles or after solubilization and purification in dodecyl-β-D-maltopyranoside (DDM). Unlike the pseudo-WT, Cys replacements on the periplasmic side of the Cys154 → Gly mutant label rapidly in the membrane without sugar, but labeling decreases markedly after the mutant proteins are purified. Thus, Cys154 → Gly LacY likely favors a higher-energy intermediate periplasmic-open conformation in situ, but collapses to a lower-energy periplasmic-closed conformation in DDM after purification. Notably, branched-chain or neopentyl glycol maltoside detergents stabilize Cys154 → Gly LacY in the membrane-embedded form.

  4. PRODUCTION HALIEUTIQUE DU LAC FAE (BASSIN DU SAN ...

    African Journals Online (AJOL)

    about 5.229 millions CFA for the shrimp production at the rate of 1500 Flkg. .... Figure 1 Lac Fae-Localisation geographique, zones de production, secteurs et ... embankment dam ; d : water intake for regulating the threshold level of water in the.

  5. 76 FR 68124 - Television Broadcasting Services; Fond du Lac, WI

    Science.gov (United States)

    2011-11-03

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [MB Docket No. 09-115, RM-11543; DA 11-1502] Television Broadcasting Services; Fond du Lac, WI AGENCY: Federal Communications Commission. ACTION: Proposed rule. SUMMARY: In this document, the Commission denies a petition for reconsideration of an August 12...

  6. lac operon induction in Escherichia coli: Systematic comparison of IPTG and TMG induction and influence of the transacetylase LacA.

    Science.gov (United States)

    Marbach, Anja; Bettenbrock, Katja

    2012-01-01

    Most commonly used expression systems in bacteria are based on the Escherichia coli lac promoter. Furthermore, lac operon elements are used today in systems and synthetic biology. In the majority of the cases the gratuitous inducers IPTG or TMG are used. Here we report a systematic comparison of lac promoter induction by TMG and IPTG which focuses on the aspects inducer uptake, population heterogeneity and a potential influence of the transacetylase, LacA. We provide induction curves in E. coli LJ110 and in isogenic lacY and lacA mutant strains and we show that both inducers are substrates of the lactose permease at low inducer concentrations but can also enter cells independently of lactose permease if present at higher concentrations. Using a gfp reporter strain we compared TMG and IPTG induction at single cell level and showed that bimodal induction with IPTG occurred at approximately ten-fold lower concentrations than with TMG. Furthermore, we observed that lac operon induction is influenced by the transacetylase, LacA. By comparing two Plac-gfp reporter strains with and without a lacA deletion we could show that in the lacA(+) strain the fluorescence level decreased after few hours while the fluorescence further increased in the lacA(-) strain. The results indicate that through the activity of LacA the IPTG concentration can be reduced below an inducing threshold concentration-an influence that should be considered if low inducer amounts are used. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. A geological survey of the Lac du Bonnet batholith, Manitoba

    International Nuclear Information System (INIS)

    McCrank, G.F.D.

    1985-02-01

    This report presents the results of a geological survey of the Lac du Bonnet batholith in Manitoba. The survey consisted of field mapping of the lithologies and the joint systems throughout the batholith, and the examination of lineaments identified on aerial photographs and Landsat imagery. Petrographic descriptions and a map of the lithologies, an analysis of the fracture systems and a lineament map are presented. The results of various regional geophysical surveys were used as an aid to the interpretation of the batholith's contacts and in the interpretation of lineaments as possible faults. A comparison of the Lac du Bonnet Batholith with the Eye-Dashwa Lakes Pluton near Atikokan, Ontario is also presented

  8. Evolution and Biophysics of the Escherichia coli lac Operon

    Science.gov (United States)

    Ray, J. Christian; Igoshin, Oleg; Quan, Selwyn; Monds, Russell; Cooper, Tim; Balázsi, Gábor

    2011-03-01

    To understand, predict, and control the evolution of living organisms, we consider biophysical effects and molecular network architectures. The lactose utilization system of E. coli is among the most well-studied molecular networks in biology, making it an ideal candidate for such studies. Simulations show how the genetic architecture of the wild-type operon attenuates large metabolic intermediate fluctuations that are predicted to occur in an equivalent system with the component genes on separate operons. Quantification of gene expression in the lac operon evolved in growth conditions containing constant lactose, alternating with glucose, or constant glucose, shows characteristic gene expression patterns depending on conditions. We are simulating these conditions to show context-dependent biophysical sources and costs of different lac operon architectures.

  9. Du Lac de Geneve au Lac Baikal: deux metropoles en construction

    Directory of Open Access Journals (Sweden)

    Guy Mettan

    2006-08-01

    Full Text Available En apparence, Geneve et Irkutsk n'ont rien en commun. A part une amitie reciproque et la proximite d'un lac, il est difficile de trouver des points communs entre la Suisse francophone, dont Geneve est la ville le plus importante, et la Siberie centrale, dont Irkutsk, est la capitale. Et pourtant les deux regions, malgre les differences de taille, de densite de la population, de climat, d'economie et de traditions culturelles, sont confrontees au meme probleme: elles sont trop petites et trop limitees pour assurer, avec leurs seuls moyens, leur avenir et elles doivent imperativement s'unir a des villes voisines pour renforcer leur statut de metropole regionale et s'imposer face aux regions et aux pays concurrents.C'est ainsi qu'Irkutsk projette de s'unir aux villes voisines d'Angarsk et de Chelekhov pour constituer une megapole au c?ur de la Siberie, tandis qu'a Geneve le debat fait rage pour trouver des solutions a l'exiguite geographique et a l'insuffisance des moyens face aux grandes regions metropolitaines de France, d'Italie et d'Allemagne.Ce debat est propre a toute la Suisse. Malgre sa petitesse, la Suisse est divisee en 26 cantons. Ces unites administratives sont jugees trop couteuses, trop petites, trop lourdes et trop compliquees pour assurer l'avenir economique et meme politique du pays. De nombreux groupes de reflexion proposent donc de reduire ce nombre a 3, 5 ou 10 grandes provinces selon les cas. En Suisse, romande, il y a dix ans, des mouvements politiques ont meme lance l'idee de fusionner les cantons de Vaud (dont Lausanne est la capitale et de Geneve. Mais l'echec a ete fracassant : le peuple des deux cantons a refuse cette option a 80% des voix. On cherche donc d'autres solutions.Les discussions s'orientent desormais autour de la constitution d'une grande metropole lemanique qui regrouperait les deux grandes villes de Geneve et Lausanne et les villes plus petites de Montreux, Vevey, Nyon ainsi que la ville francaise d

  10. A geological reconnaissance study of the Lac du Bonnet batholith

    International Nuclear Information System (INIS)

    Tammemagi, H.Y.; Kerford, P.S.; Requeima, J.C.; Temple, C.A.

    1980-02-01

    A geological reconnaissance survey was carried out of the Lac du Bonnet batholith, southeastern Manitoba, as part of the concept verification phase of the nuclear fuel waste disposal program for Canada. This report summarizes available geological information, presents the results of field mapping and discusses the geochemical analyses of rock samples. The geological and structural aspects of the batholith are described as well as its regional setting and possible genesis. (auth)

  11. cas du lac Fetzara, région de Annaba

    African Journals Online (AJOL)

    ruissellement, elles acquièrent une nouvelle composition différente de celle des eaux de pluie. Les apports par les précipitations météoriques. Chaque mois pluvieux a fait l'objet d'une analyse chimique et une moyenne des concentrations des eaux apportées au lac a été estimée. La quantité des éléments apportés par.

  12. Characterisation and discrimination of various types of lac resin using gas chromatography mass spectrometry techniques with quaternary ammonium reagents.

    Science.gov (United States)

    Sutherland, K; del Río, J C

    2014-04-18

    A variety of lac resin samples obtained from artists' suppliers, industrial manufacturers, and museum collections were analysed using gas chromatography mass spectrometry (GCMS) and reactive pyrolysis GCMS with quaternary ammonium reagents. These techniques allowed a detailed chemical characterisation of microgram-sized samples, based on the detection and identification of derivatives of the hydroxy aliphatic and cyclic (sesquiterpene) acids that compose the resin. Differences in composition could be related to the nature of the resin, e.g. wax-containing (unrefined), bleached, or aged samples. Furthermore, differences in the relative abundances of aliphatic hydroxyacids appear to be associated with the biological source of the resin. The diagnostic value of newly characterised lac components, including 8-hydroxyacids, is discussed here for the first time. Identification of derivatised components was aided by AMDIS deconvolution software, and discrimination of samples was enhanced by statistical evaluation of data using principal component analysis. The robustness of the analyses, together with the minimal sample size required, make these very powerful approaches for the characterisation of lac resin in museum objects. The value of such analyses for enhancing the understanding of museum collections is illustrated by two case studies of objects in the collection of the Philadelphia Museum of Art: a restorer's varnish on a painting by Luca Signorelli, and a pictorial inlay in an early nineteenth-century High Chest by George Dyer. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Complex genomic rearrangement in CCS-LacZ transgenic mice.

    Science.gov (United States)

    Stroud, Dina Myers; Darrow, Bruce J; Kim, Sang Do; Zhang, Jie; Jongbloed, Monique R M; Rentschler, Stacey; Moskowitz, Ivan P G; Seidman, Jonathan; Fishman, Glenn I

    2007-02-01

    The cardiac conduction system (CCS)-lacZ insertional mouse mutant strain genetically labels the developing and mature CCS. This pattern of expression is presumed to reflect the site of transgene integration rather than regulatory elements within the transgene proper. We sought to characterize the genomic structure of the integration locus and identify nearby gene(s) that might potentially confer the observed CCS-specific transcription. We found rearrangement of chromosome 7 between regions D1 and E1 with altered transcription of multiple genes in the D1 region. Several lines of evidence suggested that regulatory elements from at least one gene, Slco3A1, influenced CCS-restricted reporter gene expression. In embryonic hearts, Slco3A1 was expressed in a spatial pattern similar to the CCS-lacZ transgene and was similarly neuregulin-responsive. At later stages, however, expression patterns of the transgene and Slco3A1 diverged, suggesting that the Slco3A1 locus may be necessary, but not sufficient to confer CCS-specific transgene expression in the CCS-lacZ line. (c) 2007 Wiley-Liss, Inc.

  14. METHODICAL APPROACHES TO THE CREATION MOOC (EXPERIENCE LAC

    Directory of Open Access Journals (Sweden)

    Larysa Nozdrina

    2016-03-01

    Full Text Available The article presents a number of problems, determining the current state of development of the domestic market of massive open online courses (MOOC. Considering the aim of the research, there is described national experience in this area, proposed and substantiated a number of the criteria and methodological approaches to the implementation of MOOC in higher education. The development of MOOC in the Lviv Academy of Commerce (LAC is reviewed as example. The main factors which determine the success of this educational innovation in the domestic market and are put under the research are software platforms, multimedia software for creating video lectures, course structure and support the learning process. The results of study which have been analyzed in this course can have a positive impact on the functioning of the market MOOC in Ukrainian universities. The article focuses on finding the ways of improving the process of developing and implementing MOOC in higher education in the example of LAC where Web-center on the MOODLE platform is used for e-learning. Further research should focus on the development of institutional mechanisms to ensure the effective design, implementation and operation of the MOOC in the universities in Ukraine. Particular attention during learning in massive open online course should be aimed at improving the educational process and to strengthen student's motivation in MOOC. Experience of MOOC's development in LAC can be useful at creating similar courses at other institutions of higher education in the different platforms, both MOODLE, and on the others

  15. NEW HIGH- z FERMI BL LACS WITH THE PHOTOMETRIC DROPOUT TECHNIQUE

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, A.; Ajello, M.; Hartmann, D. H.; Paliya, V. S. [Department of Physics and Astronomy, Clemson University, SC 29634-0978 (United States); Rau, A.; Greiner, J.; Bolmer, J.; Schady, P. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße 1, D-85748 Garching (Germany); Domínguez, A., E-mail: akaur@g.clemson.edu [Grupo de Altas Energías, Universidad Complutense, E-28040 Madrid (Spain)

    2017-01-01

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

  16. Northern hemisphere mid-latitude geomagnetic anomaly revealed from Levantine Archaeomagnetic Compilation (LAC).

    Science.gov (United States)

    Shaar, R.; Tauxe, L.; Agnon, A.; Ben-Yosef, E.; Hassul, E.

    2015-12-01

    The rich archaeological heritage of Israel and nearby Levantine countries provides a unique opportunity for archaeomagnetic investigation in high resolution. Here we present a summary of our ongoing effort to reconstruct geomagnetic variations of the past several millennia in the Levant at decadal to millennial resolution. This effort at the Southern Levant, namely the "Levantine Archaeomagnetic Compilation" (LAC), presently consists of data from over 650 well-dated archaeological objects including pottery, slag, ovens, and furnaces. In this talk we review the methodological challenges in achieving a robust master secular variation curve with realistic error estimations from a large number of different datasets. We present the current status of the compilation, including the southern and western Levant LAC data (Israel, Cyprus, and Jordan) and other published north-eastern Levant data (Syria and southern Turkey), and outline the main findings emerging from these data. The main feature apparent from the new compilation is an extraordinary intensity high that developed over the Levant region during the first two millennia BCE. The climax of this event is a double peak intensity maximum starting at ca. 1000 BCE and ending at ca. 735 BCE, accompanied with at least two events of geomagnetic spikes. Paleomagnetic directions from this period demonstrate anomalies of up to 20 degrees far from the averaged GAD field. This leads us to postulate that the maximum in the intensity is a manifestation of an intense mid-latitude local positive geomagnetic anomaly that persisted for over two centuries.

  17. Gene-mutation assays in lambda-lacZ transgenic mice : comparison of lacZ with endogenous genes in splenocytes and small intestinal epithelium

    NARCIS (Netherlands)

    Delft, J.H.M. van; Bergmans, A.; Dam, F.J. van; Tates, A.D.; Howard, L.; Winton, D.J.; Baan, R.A.

    1998-01-01

    Comparison of results derived from transgenic animal gene-mutation assays with those from mutation analyses in endogenous genes is an important step in the validation of the former. We have used λlacZ transgenic mice to study alkylation-induced mutagenesis in vivo in (a) lacZ and hprt in spleen

  18. Induction of the lac carrier and an associated membrane protein in Escherichia coli

    International Nuclear Information System (INIS)

    Lagarias, D.M.

    1985-01-01

    Induction of the lac operon in wild type Escherichia coli strains results in synthesis of a 16 kilodalton inner membrane protein in addition to the known products of the lacZ, lacY and lacA genes. Cells carrying the lacY gene on a plasmid over produce this 16 kilodalton polypeptide as well as the Lac carrier, the membrane protein product of the lacY gene. However, [ 35 S]methionine labeling of minicells carrying the lacY plasmid shows that the 16 kDa protein is not synthesized from the plasmid DNA. The 16 kDa protein was purified and partially characterized. It is an acidic membrane protein of apparent molecular weight 15,800 whose amino terminal sequence (NH 2 -Met-Arg-Asn-Phe-Asp-Leu-) does not correspond to any nucleotide sequence known in lac operon DNA. Using antibody prepared to the purified 16 kDa protein, a quantitative analysis of conditions under which this protein is made was accomplished, and reveals that the amount of 16 kDa protein which appears in the membrane is proportional to lac operon expression. Hybridization of a synthetic oligonucleotide probe complementary to the 5' end of 16 kDa protein mRNA shows that its synthesis is regulated at the level of transcription. A description of attempts to clone this gene is given. Possible functional roles for the 16 kDa protein are discussed

  19. No evidence for radio-quiet BL Lacertae objects

    International Nuclear Information System (INIS)

    Stocke, J.T.; Morris, S.L.; Gioia, I.; Maccacaro, T.; Schild, R.E.

    1990-01-01

    Using a large, flux-limited sample of faint X-ray sources, a search has been conducted for radio-quiet BL Lacertae objects. None has been found. Thirty-two X-ray-selected BL Lac objects and BL Lac candidates have been found within the sources of the Einstein Medium Sensitivity Survey (EMSS). Thirty-one of these have been observed with the VLA and all have been detected at 5 GHz. While the optical magnitudes of the EMSS BL Lac objects range from 17 to 20.8, their radio-to-optical spectral indices occupy a very small range. The very bright X-ray-selected BL Lac objects like PKS 2155-304 and Markarian 501 have similar range values. Therefore, unlike the clear dichotomy between radio-loud quasars and radio-quiet QSOs, there is no evidence for two populations of Lacertids distinguished by radio loudness. 43 refs

  20. Chemo-enzymatic modification of poly-N-acetyllactosamine (LacNAc oligomers and N,N-diacetyllactosamine (LacDiNAc based on galactose oxidase treatment

    Directory of Open Access Journals (Sweden)

    Christiane E. Kupper

    2012-05-01

    Full Text Available The importance of glycans in biological systems is highlighted by their various functions in physiological and pathological processes. Many glycan epitopes on glycoproteins and glycolipids are based on N-acetyllactosamine units (LacNAc; Galβ1,4GlcNAc and often present on extended poly-LacNAc glycans ([Galβ1,4GlcNAc]n. Poly-LacNAc itself has been identified as a binding motif of galectins, an important class of lectins with functions in immune response and tumorigenesis. Therefore, the synthesis of natural and modified poly-LacNAc glycans is of specific interest for binding studies with galectins as well as for studies of their possible therapeutic applications. We present the oxidation by galactose oxidase and subsequent chemical or enzymatic modification of terminal galactose and N-acetylgalactosamine residues of poly-N-acetyllactosamine (poly-LacNAc oligomers and N,N-diacetyllactosamine (LacDiNAc by galactose oxidase. Product formation starting from different poly-LacNAc oligomers was characterised and optimised regarding formation of the C6-aldo product. Further modification of the aldehyde containing glycans, either by chemical conversion or enzymatic elongation, was established. Base-catalysed β-elimination, coupling of biotin–hydrazide with subsequent reduction to the corresponding hydrazine linkage, and coupling by reductive amination to an amino-functionalised poly-LacNAc oligomer were performed and the products characterised by LC–MS and NMR analysis. Remarkably, elongation of terminally oxidised poly-LacNAc glycans by β3GlcNAc- and β4Gal-transferase was also successful. In this way, a set of novel, modified poly-LacNAc oligomers containing terminally and/or internally modified galactose residues were obtained, which can be used for binding studies and various other applications.

  1. The near-infrared continua of BL Lacertae objects

    International Nuclear Information System (INIS)

    Allen, D.A.; Ward, M.J.; Hyland, A.R.

    1982-01-01

    Accurate photometry at J, H and K (1.2 to 2.2 μm) has been secured of 53 BL Lac objects. A power-law continuum is an exceptionally good fit to the data, and the colours are distinct from those of quasars. There is no indication of the additional infrared continuum seen in quasars and which is believed to arise in circumnuclear dust. We argue that dust is very scarce in the nuclei of BL Lac objects, and thus we expect gas to be equally scarce. Hence we attribute the lack of optical emission lines to an absence of ionized nuclear gas. We further argue that BL Lac objects could underlie quasars, the latter exhibiting line and thermal continuum emission at ultraviolet, optical and near-infrared wavelengths due to the presence of circumnuclear gas and dust. The strong-lined optically violent variable quasars have colours typical of BL Lac objects rather than quasars, and may represent intermediate cases. The JHK colours of the BL Lac objects overlap with those of the empty-radio-field infrared sources. Such objects probably represent the redder extreme of a range of spectral indices in BL Lac objects. (author)

  2. Probing BL Lac and Cluster Evolution via a Wide-angle, Deep X-ray Selected Sample

    Science.gov (United States)

    Perlman, E.; Jones, L.; White, N.; Angelini, L.; Giommi, P.; McHardy, I.; Wegner, G.

    1994-12-01

    The WARPS survey (Wide-Angle ROSAT Pointed Survey) has been constructed from the archive of all public ROSAT PSPC observations, and is a subset of the WGACAT catalog. WARPS will include a complete sample of >= 100 BL Lacs at F_x >= 10(-13) erg s(-1) cm(-2) . A second selection technique will identify ~ 100 clusters at 0.15 = 0.304 +/- 0.062 for XBLs but = 0.60 +/- 0.05 for RBLs. Models of the X-ray luminosity function (XLF) are also poorly constrained. WARPS will allow us to compute an accurate XLF, decreasing the error bars above by over a factor of two. We will also test for low-luminosity BL Lacs, whose non-thermal nuclear sources are dim compared to the host galaxy. Browne and Marcha (1993) claim the EMSS missed most of these objects and is incomplete. If their predictions are correct, 20-40% of the BL Lacs we find will fall in this category, enabling us to probe the evolution and internal workings of BL Lacs at lower luminosities than ever before. By removing likely QSOs before optical spectroscopy, WARPS requires only modest amounts of telescope time. It will extend measurement of the cluster XLF both to higher redshifts (z>0.5) and lower luminosities (LX<1x10(44) erg s(-1) ) than previous measurements, confirming or rejecting the 3sigma detection of negative evolution found in the EMSS, and constraining Cold Dark Matter cosmologies. Faint NELGs are a recently discovered major contributor to the X-ray background. They are a mixture of Sy2s, starbursts and galaxies of unknown type. Detailed classification and evolution of their XLF will be determined for the first time.

  3. The business of refractive laser assisted cataract surgery (ReLACS).

    Science.gov (United States)

    Berdahl, John P; Jensen, Matthew P

    2014-01-01

    Refractive Laser Assisted Cataract Surgery (ReLACS) combines the femtosecond laser with other noncovered tests and services in an attempt to reduce spectacle dependence in combination with cataract surgery. Significant interest is present among ophthalmologists who are considering adopting this technology, however significant capital outlays and continuing expenses can make the decision to adopt ReLACS foreboding. We review the financial considerations of ReLACS and review the trends seen in early adopters of this technology. Recent findings have shown that ReLACS is a growing segment of cataract surgery. Most practices who have implemented the technology have broken even and have a positive outlook on the financial return of implementing the ReLACS program. The average break-even analysis point for practices is around 230 cases a year. ReLACS is growing and appears to be a financial viable approach for many practices.

  4. Physico-Mechanical Properties of Coprocessed Excipient MicroceLac® 100 by DM(3) Approach.

    Science.gov (United States)

    Haware, Rahul V; Kancharla, Joseph P; Udupa, Aishwarya K; Staton, Scott; Gupta, Mali R; Al-Achi, Antoine; Stagner, William C

    2015-11-01

    To determine the effect of relative humidity (RH) and hydroxypropyl methylcellulose (HPMC) on the physico-mechanical properties of coprocessed MacroceLac(®) 100 using 'DM(3)' approach. Effects of RH and 5% w/w HPMC on MacroceLac(®) 100 Compressibility Index (CI) and tablet mechanical strength (TMS) were evaluated by 'DM(3)'. The 'DM(3)' approach evaluates material properties by combining 'design of experiments', material's 'macroscopic' properties, 'molecular' properties, and 'multivariate analysis' tools. A 4X4 full-factorial experimental design was used to study the relationship of MacroceLac(®) 100 molecular properties (moisture content, dehydration, crystallization, fusion enthalpy, and moisture uptake) and macroscopic particle size and shape on CI and TMS. A physical binary mixture (PBM) of similar composition to MacroceLac(®) 100 was also evaluated. Multivariate analysis of variance (MANOVA), principle component analysis, and partial least squares (PLS) were used to analyze the data. MANOVA CI ranking was: PBM-HPMC > PBM > MicroceLac(®)100 > MicroceLac(®)100-HPMC (p TMS values were lower than MicroceLac(®)100 and MicroceLac(®)100-HPMC (p TMS. Significant MicroceLac(®)100 changes occurred with % RH exposure affecting performance attributes. HPMC physical addition did not prevent molecular or macroscopic matrix changes.

  5. The cosmic evolution of Fermi BL Lacertae objects

    International Nuclear Information System (INIS)

    Ajello, M.; Romani, R. W.; Shaw, M. S.; Healey, S. E.; Michelson, P. F.; Gasparrini, D.; Bolmer, J.; Cotter, G.; Potter, W. J.; Finke, J.; Greiner, J.; Rau, A.; Schady, P.; King, O.; Max-Moerbeck, W.; Readhead, A. C. S.; Richards, J. L.

    2014-01-01

    Fermi has provided the largest sample of γ-ray-selected blazars to date. In this work we use a uniformly selected set of 211 BL Lacertae (BL Lac) objects detected by Fermi during its first year of operation. We obtained redshift constraints for 206 out of the 211 BL Lac objects in our sample, making it the largest and most complete sample of BL Lac objects available in the literature. We use this sample to determine the luminosity function of BL Lac objects and its evolution with cosmic time. We find that for most BL Lac classes the evolution is positive, with a space density peaking at modest redshift (z ≈ 1.2). Low-luminosity, high-synchrotron-peaked (HSP) BL Lac objects are an exception, showing strong negative evolution, with number density increasing for z ≲ 0.5. Since this rise corresponds to a drop-off in the density of flat-spectrum radio quasars (FSRQs), a possible interpretation is that these HSPs represent an accretion-starved end state of an earlier merger-driven gas-rich phase. We additionally find that the known BL Lac correlation between luminosity and photon spectral index persists after correction for the substantial observational selection effects with implications for the so-called 'blazar sequence'. Finally, by estimating the beaming corrections to the luminosity function, we find that BL Lac objects have an average Lorentz factor of γ=6.1 −0.8 +1.1 , and that most are seen within 10° of the jet axis.

  6. The NuSTAR view on Hard-TeV BL Lacs

    Science.gov (United States)

    Costamante, L.; Bonnoli, G.; Tavecchio, F.; Ghisellini, G.; Tagliaferri, G.; Khangulyan, D.

    2018-05-01

    Hard-TeV BL Lacs are a new type of blazars characterized by a hard intrinsic TeV spectrum, locating the peak of their gamma-ray emission in the spectral energy distribution (SED) above 2-10 TeV. Such high energies are problematic for the Compton emission, using a standard one-zone leptonic model. We study six examples of this new type of BL Lacs in the hard X-ray band with NuSTAR. Together with simultaneous observations with the Neil Gehrels Swift Observatory, we fully constrain the peak of the synchrotron emission in their SED, and test the leptonic synchrotron self-Compton (SSC) model. We confirm the extreme nature of 5 objects also in the synchrotron emission. We do not find evidence of additional emission components in the hard X-ray band. We find that a one-zone SSC model can in principle reproduce the extreme properties of both peaks in the SED, from X-ray up to TeV energies, but at the cost of i) extreme electron energies with very low radiative efficiency, ii) conditions heavily out of equipartition (by 3 to 5 orders of magnitude), and iii) not accounting for the simultaneous UV data, which then should belong to a different emission component, possibly the same as the far-IR (WISE) data. We find evidence of this separation of the UV and X-ray emission in at least two objects. In any case, the TeV electrons must not "see" the UV or lower-energy photons, even if coming from different zones/populations, or the increased radiative cooling would steepen the VHE spectrum.

  7. Louisiana SIP: LAC 33:III Ch 21 Subchap J, 2147--Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 1998-02-02 (LAc74) to more..

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch 21 Subchap J, 2147--Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 1998-02-02 (LAc74) more...

  8. In vivo biocompatibility of p(HPMAm-lac)-PEG hydrogels hybridized with hyaluronan

    NARCIS (Netherlands)

    Sabbieti, Maria Giovanna; Dubbini, Alessandra; Laus, Fulvio; Paggi, Emanuele; Marchegiani, Andrea; Capitani, Melania; Marchetti, Luigi; Dini, Fabrizio; Vermonden, Tina; Di Martino, Piera; Agas, Dimitrios; Censi, Roberta

    2017-01-01

    The present study reports on the biocompatibility in vivo after intramuscular and subcutaneous administration in Balb/c mice of vinyl sulphone bearing p(HPMAm-lac1-2)-PEG-p(HPMAm-lac1-2)/thiolated hyaluronic acid hydrogels, designed as novel injectable biomaterials for potential application in the

  9. Crisis in LAC : Infrastructure Investment, Employment and the Expectations of Stimulus

    OpenAIRE

    Schwartz, Jordan; Andres, Luis; Dragoiu, Georgeta

    2009-01-01

    Infrastructure investment is a central part of the stimulus plans of the Latin America and the Caribbean (LAC) region as it confronts the growing financial crisis. This paper estimates the potential effects on direct, indirect, and induced employment for different types of infrastructure projects with LAC-specific variables. The analysis finds that the direct and indirect short-term employ...

  10. On the close environment of BL Lacertae objects

    Energy Technology Data Exchange (ETDEWEB)

    Falomo, R. (Osservatorio Astronomico di Padova (Italy)); Melnick, J. (European Southern Observatory, Santiago (Chile)); Tanzi, E.G. (Consiglio Nazionale delle Ricerche, Milan (Italy))

    1990-06-21

    The local environment of BL Lacertae objects, which resemble quasars but lack emission lines, is poorly understood. In the few cases where the surrounding nebulosity has been studied in detail, it is consistent with the presence of a giant elliptical galaxy, but the evidence that the BL Lac and the putative galaxy are physically associated rests solely on their positional coincidence. An alternative hypothesis, that BL Lacs are gravitationally lensed and that the surrounding emission is from the foreground lensing object, gains some support from a number of observations which reveal less than perfect alignment between BL Lacs and surrounding emission. We have begun a systematic programme of high-resolution imaging aimed at understanding in a general way the local environment of BL Lacs. Here we describe a first series of images, which show the presence of emission features around most of the BL Lacs observed. Typically, this emission is close (<5 arcsec) to the BL Lac, and faint (m{sub R} = 21). We discuss the interpretation of these companions in terms of both interacting objects and gravitational lenses. (author).

  11. Radiocarbon measurements at LAC-UFF: Recent performance

    Energy Technology Data Exchange (ETDEWEB)

    Linares, Roberto, E-mail: rlinares@if.uff.br [Laboratório de Radiocarbono, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n, Niterói 24230-346 (Brazil); Macario, Kita D. [Laboratório de Radiocarbono, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n, Niterói 24230-346 (Brazil); Santos, Guaciara M. [Earth System Science, University of California, Irvine, B321 Croul Hall, Irvine, CA 92697-3100 (United States); Carvalho, Carla [Laboratório de Radiocarbono, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n, Niterói 24230-346 (Brazil); Departamento de Geoquímica, Universidade Federal Fluminense, Outeiro São João Batista, s/n, Niterói 24020-141 (Brazil); Santos, Hellen C. dos; Gomes, Paulo R.S.; Castro, Maikel D.; Oliveira, Fabiana M.; Alves, Eduardo Q. [Laboratório de Radiocarbono, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n, Niterói 24230-346 (Brazil)

    2015-10-15

    In 2012 a single stage accelerator mass spectrometer from NEC was installed at the Radiocarbon Laboratory of Universidade Federal Fluminense (LAC-UFF), Niterói, Brazil. Here, we present a status report of our facility. We discuss some modifications applied to our combustion protocol in an attempt to reduce our procedural blank, mostly to processed organic samples. Measurements of reference materials indicate low precision and accuracy that are partially related to beam optics through the acceleration tube. We observed that once the beam current intensity increases the measured {sup 13}C{sup +}/{sup 12}C{sup +} becomes erratic. Therefore, in order to maintain the AMS-δ{sup 13}C values within reasonable values, so that fractionation corrections using the spectrometer {sup 13}C{sup +}/{sup 12}C{sup +} values does not affect the final {sup 14}C results, we are forced to limit the {sup 12}C{sup −} beam intensity to ⩽30 μA. This requirement was confirmed during our accuracy tests, when measuring selected annual tree-rings wood samples from a Parana pine (Araucaria angustifolia) between 1927 and 1997 previously measured at the Keck Carbon Cycle AMS Facility (KCCAMS), at the University of California, Irvine (UCI). At the LAC-UFF tree-ring wood samples were processed and measured in 4 different batches during a period of about 5 months. The {sup 14}C results were later compared to the high-precision data obtained at KCCAMS/UCI and reached a good agreement. Recently a problem associated with graphitization yield were finally identified and new measurements with secondary standards are promising.

  12. Louisiana SIP: LAC 33:III Ch. 7 - Table 2 - Ambient Air--Methods of Contaminant Measurements; SIP effective 1989-05-08 (LAc49) and 1989-08-14 (LAc50) to 2011-08-03 (LAd34 - Moved to Section 711 and revised [adds PM-2.5])

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch. 7 - Table 2 - Ambient Air--Methods of Contaminant Measurements; SIP effective 1989-05-08 (LAc49) and 1989-08-14 (LAc50) to 2011-08-03 (LAd34 - Moved to Section 711 and revised [adds PM-2.5])

  13. Testing the blazar sequence and black hole mass scaling with BL Lac objects

    NARCIS (Netherlands)

    Plotkin, Richard M.; Markoff, Sera; Anderson, Scott F.; Kelly, Brandon C.; Körding, Elmar; Trager, Scott C.; Romero, Gustavo E.; Sunyaev, Rashid A.; Belloni, Tomaso

    Jets from accreting black holes appear remarkably similar over eight orders of magnitude in black hole mass, with more massive black holes generally launching more powerful jets. For example, there is an observed correlation, termed the fundamental plane of black hole accretion, between black hole

  14. Testing the blazar sequence and black hole mass scaling with BL Lac objects

    NARCIS (Netherlands)

    Plotkin, R.M.; Markoff, S.; Anderson, S.F.; Kelly, B.C.; Körding, E.; Trager, S.C.

    2010-01-01

    Jets from accreting black holes appear remarkably similar over eight orders of magnitude in black hole mass, with more massive black holes generally launching more powerful jets. For example, there is an observed correlation, termed the fundamental plane of black hole accretion, between black hole

  15. Modelling the IDV Emissions of the BL Lac Objects with a Langevin ...

    Indian Academy of Sciences (India)

    2Department of Physics and Center for Theoretical and Computational Physics,. The University of ... The mathematical model is formulated in ... approximate the distribution of the surface density in the geometrically thin disk by the formulae. = ... Radj = 75Rin, while the outer radius of the disk is located at Rout = 250Rin. By.

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

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... 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.

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

    Indian Academy of Sciences (India)

    tal method and then simulate the data with the Weierstrass–Mandelbrot. (W–M) function. It is considered that the ... The infrared observation indicated that the interstellar clouds have a fractal structure with dimension ... The observational data of the R-band (top panel) and simulation data with W–M function (bottom panel).

  18. Dissecting the long-term emission behaviour of the BL Lac object Mrk 421

    Science.gov (United States)

    Carnerero, M. I.; Raiteri, C. M.; Villata, M.; Acosta-Pulido, J. A.; Larionov, V. M.; Smith, P. S.; D'Ammando, F.; Agudo, I.; Arévalo, M. J.; Bachev, R.; Barnes, J.; Boeva, S.; Bozhilov, V.; Carosati, D.; Casadio, C.; Chen, W. P.; Damljanovic, G.; Eswaraiah, E.; Forné, E.; Gantchev, G.; Gómez, J. L.; González-Morales, P. A.; Griñón-Marín, A. B.; Grishina, T. S.; Holden, M.; Ibryamov, S.; Joner, M. D.; Jordan, B.; Jorstad, S. G.; Joshi, M.; Kopatskaya, E. N.; Koptelova, E.; Kurtanidze, O. M.; Kurtanidze, S. O.; Larionova, E. G.; Larionova, L. V.; Latev, G.; Lázaro, C.; Ligustri, R.; Lin, H. C.; Marscher, A. P.; Martínez-Lombilla, C.; McBreen, B.; Mihov, B.; Molina, S. N.; Moody, J. W.; Morozova, D. A.; Nikolashvili, M. G.; Nilsson, K.; Ovcharov, E.; Pace, C.; Panwar, N.; Pastor Yabar, A.; Pearson, R. L.; Pinna, F.; Protasio, C.; Rizzi, N.; Redondo-Lorenzo, F. J.; Rodríguez-Coira, G.; Ros, J. A.; Sadun, A. C.; Savchenko, S. S.; Semkov, E.; Slavcheva-Mihova, L.; Smith, N.; Strigachev, A.; Troitskaya, Yu. V.; Troitsky, I. S.; Vasilyev, A. A.; Vince, O.

    2017-12-01

    We report on long-term multiwavelength monitoring of blazar Mrk 421 by the GLAST-AGILE Support Program of the Whole Earth Blazar Telescope (GASP-WEBT) collaboration and Steward Observatory, and by the Swift and Fermi satellites. We study the source behaviour in the period 2007-2015, characterized by several extreme flares. The ratio between the optical, X-ray and γ-ray fluxes is very variable. The γ-ray flux variations show a fair correlation with the optical ones starting from 2012. We analyse spectropolarimetric data and find wavelength-dependence of the polarization degree (P), which is compatible with the presence of the host galaxy, and no wavelength dependence of the electric vector polarization angle (EVPA). Optical polarimetry shows a lack of simple correlation between P and flux and wide rotations of the EVPA. We build broad-band spectral energy distributions with simultaneous near-infrared and optical data from the GASP-WEBT and ultraviolet and X-ray data from the Swift satellite. They show strong variability in both flux and X-ray spectral shape and suggest a shift of the synchrotron peak up to a factor of ∼50 in frequency. The interpretation of the flux and spectral variability is compatible with jet models including at least two emitting regions that can change their orientation with respect to the line of sight.

  19. lac repressor is an antivirulence factor of Salmonella enterica: its role in the evolution of virulence in Salmonella.

    Directory of Open Access Journals (Sweden)

    Sandeepa M Eswarappa

    Full Text Available The genus Salmonella includes many pathogens of great medical and veterinary importance. Bacteria belonging to this genus are very closely related to those belonging to the genus Escherichia. lacZYA operon and lacI are present in Escherichia coli, but not in Salmonella enterica. It has been proposed that Salmonella has lost lacZYA operon and lacI during evolution. In this study, we have investigated the physiological and evolutionary significance of the absence of lacI in Salmonella enterica. Using murine model of typhoid fever, we show that the expression of LacI causes a remarkable reduction in the virulence of Salmonella enterica. LacI also suppresses the ability of Salmonella enterica to proliferate inside murine macrophages. Microarray analysis revealed that LacI interferes with the expression of virulence genes of Salmonella pathogenicity island 2. This effect was confirmed by RT-PCR and Western blot analysis. Interestingly, we found that SBG0326 of Salmonella bongori is homologous to lacI of Escherichia coli. Salmonella bongori is the only other species of the genus Salmonella and it lacks the virulence genes of Salmonella pathogenicity island 2. Overall, our results demonstrate that LacI is an antivirulence factor of Salmonella enterica and suggest that absence of lacI has facilitated the acquisition of virulence genes of Salmonella pathogenicity island 2 in Salmonella enterica making it a successful systemic pathogen.

  20. The genus Hypostomus Lacépède, 1803, and its Surinam representatives (Siluriformes, Loricariidae)

    NARCIS (Netherlands)

    Boeseman, M.

    1968-01-01

    CONTENTS Introduction................... 3 The generic name................. 4 The type species of Hypostomus Lacépède.......... 6 The identity of Acipenser plecostomus Linnaeus........ 9 The distribution and habitats of the Surinam species........ 12 The relationship of the Surinam

  1. Analyses de la dégradation du lac Kinkony pour la conservation du ...

    African Journals Online (AJOL)

    Le lac Kinkony fait partie des habitats clefs pour la biodiversité du Complexe des ... provide favoured habitat for numerous endemic and endangered avian, fish ... on fauna is essential for developing regional conservation and natural resource ...

  2. Multi-Wave Luminosity of High-Synchrotron-Peaked TeV BL Lacs ...

    Indian Academy of Sciences (India)

    LIR, Lγ) in the radio, near-infrared and γ-ray wave bands for HSP. TeV BL Lacs. The results show that there are significant intrinsic cor- relations between LR and Lγ and between LIR and Lγ in all states. (high/average/low), and suggest that for HSP TeV BL Lacs, the Syn- chrotron Self-Compton radiation (SSC) is the main ...

  3. Beware of your Cre-Ation: lacZ expression impairs neuronal integrity and hippocampus-dependent memory.

    Science.gov (United States)

    Reichel, J M; Bedenk, B T; Gassen, N C; Hafner, K; Bura, S A; Almeida-Correa, S; Genewsky, A; Dedic, N; Giesert, F; Agarwal, A; Nave, K-A; Rein, T; Czisch, M; Deussing, J M; Wotjak, C T

    2016-10-01

    Expression of the lacZ-sequence is a widely used reporter-tool to assess the transgenic and/or transfection efficacy of a target gene in mice. Once activated, lacZ is permanently expressed. However, protein accumulation is one of the hallmarks of neurodegenerative diseases. Furthermore, the protein product of the bacterial lacZ gene is ß-galactosidase, an analog to the mammalian senescence-associated ß-galactosidase, a molecular marker for aging. Therefore we studied the behavioral, structural and molecular consequences of lacZ expression in distinct neuronal sub-populations. lacZ expression in cortical glutamatergic neurons resulted in severe impairments in hippocampus-dependent memory accompanied by marked structural alterations throughout the CNS. In contrast, GFP expression or the expression of the ChR2/YFP fusion product in the same cell populations did not result in either cognitive or structural deficits. GABAergic lacZ expression caused significantly decreased hyper-arousal and mild cognitive deficits. Attenuated structural and behavioral consequences of lacZ expression could also be induced in adulthood, and lacZ transfection in neuronal cell cultures significantly decreased their viability. Our findings provide a strong caveat against the use of lacZ reporter mice for phenotyping studies and point to a particular sensitivity of the hippocampus formation to detrimental consequences of lacZ expression. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Genotype to phenotype mapping and the fitness landscape of the E. coli lac promoter.

    Directory of Open Access Journals (Sweden)

    Jakub Otwinowski

    Full Text Available Genotype-to-phenotype maps and the related fitness landscapes that include epistatic interactions are difficult to measure because of their high dimensional structure. Here we construct such a map using the recently collected corpora of high-throughput sequence data from the 75 base pairs long mutagenized E. coli lac promoter region, where each sequence is associated with its phenotype, the induced transcriptional activity measured by a fluorescent reporter. We find that the additive (non-epistatic contributions of individual mutations account for about two-thirds of the explainable phenotype variance, while pairwise epistasis explains about 7% of the variance for the full mutagenized sequence and about 15% for the subsequence associated with protein binding sites. Surprisingly, there is no evidence for third order epistatic contributions, and our inferred fitness landscape is essentially single peaked, with a small amount of antagonistic epistasis. There is a significant selective pressure on the wild type, which we deduce to be multi-objective optimal for gene expression in environments with different nutrient sources. We identify transcription factor (CRP and RNA polymerase binding sites in the promotor region and their interactions without difficult optimization steps. In particular, we observe evidence for previously unexplored genetic regulatory mechanisms, possibly kinetic in nature. We conclude with a cautionary note that inferred properties of fitness landscapes may be severely influenced by biases in the sequence data.

  5. République de Djibouti : lac Assal [بحيرة عسل

    OpenAIRE

    Pouyllau , Stéphane

    2009-01-01

    Vue des berges sud-est du lac Assal (République de Djibouti) le 11 novembre 2009. Le Lac Assal est un lac salé endoréique situé au fond du golfe du Ghoubbet-el-Kharab. D'une superficie de 54 km2 et fermé de la mer par le volcan Ardoukôba, sont altitude est de -153m sous le niveau de la mer.

  6. Solving a discrete model of the lac operon using Z3

    Science.gov (United States)

    Gutierrez, Natalia A.

    2014-05-01

    A discrete model for the Lcac Operon is solved using the SMT-solver Z3. Traditionally the Lac Operon is formulated in a continuous math model. This model is a system of ordinary differential equations. Here, it was considerated as a discrete model, based on a Boolean red. The biological problem of Lac Operon is enunciated as a problem of Boolean satisfiability, and it is solved using an STM-solver named Z3. Z3 is a powerful solver that allows understanding the basic dynamic of the Lac Operon in an easier and more efficient way. The multi-stability of the Lac Operon can be easily computed with Z3. The code that solves the Boolean red can be written in Python language or SMT-Lib language. Both languages were used in local version of the program as online version of Z3. For future investigations it is proposed to solve the Boolean red of Lac Operon using others SMT-solvers as cvc4, alt-ergo, mathsat and yices.

  7. WHAT IS THE REDSHIFT OF THE GAMMA-RAY BL LAC SOURCE S4 0954+65?

    Energy Technology Data Exchange (ETDEWEB)

    Landoni, M. [INAF—Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (Italy); Falomo, R. [INAF—Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Treves, A. [Universita’ degli Studi dell’Insubria, Via Valleggio 11, I-22100 (Italy); Scarpa, R.; Payá, D. Reverte, E-mail: marco.landoni@brera.inaf.it [Instituto de Astrofsica de Canarias, C/O Via Lactea, s/n E38205—La Laguna (Tenerife) (Spain)

    2015-12-15

    High signal-to-noise ratio spectroscopic observations of the BL Lac object S4 0954+65 at the alleged redshift z = 0.367 are presented. This source was detected at gamma frequencies by the MAGIC (TeV) and FERMI (GeV) telescopes during a remarkable outburst that occurred in 2015 February, making the determination of its distance particularly relevant for our understanding of the properties of the extragalactic background light. Contrary to previous reports on the redshift, we found that the optical spectrum is featureless at an equivalent width limit of ∼0.1 Å. A critical analysis of the existing observations indicates that the redshift is still unknown. Based on the new data we estimate a lower limit to the redshift at z ≥ 0.45.

  8. Lac repressor: Crystallization of intact tetramer and its complexes with inducer and operator DNA

    International Nuclear Information System (INIS)

    Pace, H.C.; Lu, P.; Lewis, M.

    1990-01-01

    The intact lac repressor tetramer, which regulates expression of the lac operon in Escherichia coli, has been crystallized in the native form, with an inducer, and in a ternary complex with operator DNA and an anti-inducer. The crystals without DNA diffract to better than 3.5 angstrom. They belong to the monoclinic space group C2 and have cell dimensions a = 164.7 angstrom, b = 75.6 angstrom, and c = 161.2 angstrom, with α = γ = 90 degree and β = 125.5 degree. Cocrystals have been obtained with a number of different lac operator-related DNA fragments. The complex with a blunt-ended 16-base-pair strand yielded tetragonal bipyramids that diffract to 6.5 angstrom. These protein-DNA cocrystals crack upon exposure to the gratuitous inducer isopropyl β-D-thiogalactoside, suggesting a conformational change in the repressor-operator complex

  9. The clean development mechanism (CDM) an international perspective and implications for the LAC region

    International Nuclear Information System (INIS)

    2004-08-01

    This paper addresses activity a) an analysis of international CDM experiences and its potential contribution to the LAC region. The paper begins with a section describing the basic principles of the CDM and retrieves the lessons learned from the first two years of the CDM operation. This is followed by a more detailed review in section 2 of the on-going baseline and monitoring methodology approval process. In section 3, the development value of the CDM is explored. Section 4 describes the current CDM markets, while section 5 reviews the response of host countries to the CDM outside the LAC region. Section 6 describes the various capacity building programs established by Annex 1 countries to support the CDM. In each of the first 6 sections, implications for the LAC region are identified. Section 7 brings these conclusions together into a concise summary. (The author)

  10. STRUCTURAL ASPECTS REGARDING TO THE IMAGE OF ICE HOTEL BALEA LAC BREND

    Directory of Open Access Journals (Sweden)

    Marian ZAHARIA

    2008-06-01

    Full Text Available Applying a poll-based survey provides important information regarding the tourist offer particulars in Bâlea Lac area. On the day the survey is performed its main advantage is also outlined: the fact that this information display a good accuracy, are obtained in a short time span and involving relatively low expenses. Data collection and centralization of the answers provided by interviewed tourists regarding tourism practice in the Bâlea Lac area have led to drawing up distributions that are presented in the paper. Based on the respective information, statistics methods adequate to the study of tourist opinion on the Bâlea Lac Ice Hotel brand image. Several issues have been outlined, regarding the types of respondents based on their category, Romanian or foreigners, from Romania and based on destination countries, function of: the type of stay; the means of information; their answers referring to their first arrival at Bâlea Lac; the degree of destination assessment; their opinion on host reception; their preference for Bâlea Lac; appreciating value for money; age groups; gender; social and professional standing. The image created through the attractions and services provided in the Bâlea Lac tourist area by tourism activities closely related to the Ice Hotel is well appreciated, so that they have opened up a rather favourable expectancy for those willing to come back and for those tempted to try and spend their holidays in the presented hotel.

  11. Lysines 72, 80 and 213 and aspartic acid 210 of the Lactococcus lactis LacR repressor are involved in the response to the inducer tagatose-6-phosphate leading to induction of lac operon expression.

    Science.gov (United States)

    van Rooijen, R J; Dechering, K J; Niek, C; Wilmink, J; de Vos, W M

    1993-02-01

    Site-directed mutagenesis of the Lactococcus lactis lacR gene was performed to identify residues in the LacR repressor that are involved in the induction of lacABCDFEGX operon expression by tagatose-6-phosphate. A putative inducer binding domain located near the C-terminus was previously postulated based on homology studies with the Escherichia coli DeoR family of repressors, which all have a phosphorylated sugar as inducer. Residues within this domain and lysine residues that are charge conserved in the DeoR family were changed into alanine or arginine. The production of the LacR mutants K72A, K80A, K80R, D210A, K213A and K213R in the LacR-deficient L.lactis strain NZ3015 resulted in repressed phospho-beta-galactosidase (LacG) activities and decreased growth rates on lactose. Gel mobility shift assays showed that the complex between a DNA fragment carrying the lac operators and LacR mutants K72A, K80A, K213A and D210A did not dissociate in the presence of tagatose-6-phosphate, in contrast to wild type LacR. Other mutations (K62A/K63A, K72R, K73A, K73R, T212A, F214R, R216R and R216K) exhibited no gross effects on inducer response. The results strongly suggest that the lysines at positions 72, 80 and 213 and aspartic acid at position 210 are involved in the induction of lac operon expression by tagatose-6-phosphate.

  12. The LAC Test: A New Look at Auditory Conceptualization and Literacy Development K-12.

    Science.gov (United States)

    Lindamood, Charles; And Others

    The Lindamood Auditory Conceptualization (LAC) Test was constructed with the recognition that the process of decoding involves an integration of the auditory, visual, and motor senses. Requiring the manipulation of colored blocks to indicate conceptualization of test patterns spoken by the examiner, subtest 1 entails coding of identity, number,…

  13. [Fond du Lac archeological resources within the Draft Area Recommendation Report

    International Nuclear Information System (INIS)

    Danz, D.L.

    1986-01-01

    Research into archaeological resources of the Fond du Lac Band within the DOE proposed high-level nuclear waste sites resulted in the discovery of four traditional ancestral sites. A number of ancestral sites that are located within other proposed repository sites were also discovered

  14. Exploring the sequence-function relationship in transcriptional regulation by the lac O1 operator.

    Science.gov (United States)

    Maity, Tuhin S; Jha, Ramesh K; Strauss, Charlie E M; Dunbar, John

    2012-07-01

    Understanding how binding of a transcription factor to an operator is influenced by the operator sequence is an ongoing quest. It facilitates discovery of alternative binding sites as well as tuning of transcriptional regulation. We investigated the behavior of the Escherichia coli Lac repressor (LacI) protein with a large set of lac O(1) operator variants. The 114 variants examined contained a mean of 2.9 (range 0-4) mutations at positions -4, -2, +2 and +4 in the minimally required 17 bp operator. The relative affinity of LacI for the operators was examined by quantifying expression of a GFP reporter gene and Rosetta structural modeling. The combinations of mutations in the operator sequence created a wide range of regulatory behaviors. We observed variations in the GFP fluorescent signal among the operator variants of more than an order of magnitude under both uninduced and induced conditions. We found that a single nucleotide change may result in changes of up to six- and 12-fold in uninduced and induced GFP signals, respectively. Among the four positions mutated, we found that nucleotide G at position -4 is strongly correlated with strong repression. By Rosetta modeling, we found a significant correlation between the calculated binding energy and the experimentally observed transcriptional repression strength for many operators. However, exceptions were also observed, underscoring the necessity for further improvement in biophysical models of protein-DNA interactions. © 2012 The Authors Journal compilation © 2012 FEBS.

  15. Transformation of lacZ using different promoters in the commercially ...

    African Journals Online (AJOL)

    Yomi

    2012-01-26

    Jan 26, 2012 ... forced growth under unnatural conditions. In order to ... yezoensis include the gluc, cat, GUS and GFP genes. (Cheney et al. ... bacterial lacZ gene encodes the β-galactosidase enzyme which is capable of .... Table 1. Effect of viral promoters on transient β-galactosidase activity in microparticle bombarded G.

  16. 77 FR 27245 - Big Stone National Wildlife Refuge, Big Stone and Lac Qui Parle Counties, MN

    Science.gov (United States)

    2012-05-09

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R3-R-2012-N069; FXRS1265030000S3-123-FF03R06000] Big Stone National Wildlife Refuge, Big Stone and Lac Qui Parle Counties, MN AGENCY: Fish and... plan (CCP) and environmental assessment (EA) for Big Stone National Wildlife Refuge (Refuge, NWR) for...

  17. Influence of salt content and processing time on sensory characteristics of cooked "lacón".

    Science.gov (United States)

    Purriños, Laura; Bermúdez, Roberto; Temperán, Sara; Franco, Daniel; Carballo, Javier; Lorenzo, José M

    2011-04-01

    The influence of salt content and processing time on the sensory properties of cooked "lacón" were determined. "Lacón" is a traditional dry-cured and ripened meat product made in the north-west of Spain from the fore leg of the pig, following a similar process to that of dry-cured ham. Six batches of "lacón" were salted with different amounts of salt (LS (3 days of salting), MS (4 days of salting) and HS (5 days of salting)) and ripened during two times (56 and 84 days of dry-ripening). Cured odour in all batches studied, red colour and rancid odour in MS and HS batches, flavour intensity in MS batch and fat yellowness, rancid flavour and hardness in the HS batch were significantly different with respect to the time of processing. Appearance, odour, flavour and texture were not significantly affected by the salt content (P>0.05). However, the saltiness score showed significant differences with respect to the salt levels in all studied batches (56 and 84 days of process). The principal component analysis showed that physicochemical traits were the most important ones concerning the quality of dry-cured "lacón" and offered a good separation of the mean samples according to the dry ripening days and salt level. © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

  18. Kinetic Analysis of Lactose Exchange in Proteoliposomes Reconstituted with Purified lac Permease

    NARCIS (Netherlands)

    Lolkema, Julius S.; Carrasco, Nancy; Kaback, H. Ronald

    1991-01-01

    Lactose exchange catalyzed by purified lac permease reconstituted into proteoliposomes was analyzed with unequal concentrations of lactose on either side of the membrane and at low pH so as to prevent equilibration of the two pools. Exchange with external concentrations below 1.0 mM is a

  19. THE CONTRIBUTION OF FERMI -2LAC BLAZARS TO DIFFUSE TEV–PEV NEUTRINO FLUX

    Energy Technology Data Exchange (ETDEWEB)

    Aartsen, M. G. [Department of Physics, University of Adelaide, Adelaide, 5005 (Australia); Abraham, K. [Physik-department, Technische Universität München, D-85748 Garching (Germany); Ackermann, M. [DESY, D-15735 Zeuthen (Germany); Adams, J. [Dept. of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Aguilar, J. A.; Ansseau, I. [Université Libre de Bruxelles, Science Faculty CP230, B-1050 Brussels (Belgium); Ahlers, M. [Dept. of Physics and Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin, Madison, WI 53706 (United States); Ahrens, M. [Oskar Klein Centre and Dept. of Physics, Stockholm University, SE-10691 Stockholm (Sweden); Altmann, D.; Anton, G. [Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Andeen, K. [Department of Physics, Marquette University, Milwaukee, WI, 53201 (United States); Anderson, T.; Arlen, T. C. [Dept. of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Archinger, M.; Baum, V. [Institute of Physics, University of Mainz, Staudinger Weg 7, D-55099 Mainz (Germany); Arguelles, C.; Axani, S. [Dept. of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Auffenberg, J. [III. Physikalisches Institut, RWTH Aachen University, D-52056 Aachen (Germany); Bai, X. [Physics Department, South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States); Barwick, S. W., E-mail: thorsten.gluesenkamp@fau.de [Dept. of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Collaboration: IceCube Collaboration; and others

    2017-01-20

    The recent discovery of a diffuse cosmic neutrino flux extending up to PeV energies raises the question of which astrophysical sources generate this signal. Blazars are one class of extragalactic sources which may produce such high-energy neutrinos. We present a likelihood analysis searching for cumulative neutrino emission from blazars in the 2nd Fermi -LAT AGN catalog (2LAC) using IceCube neutrino data set 2009-12, which was optimized for the detection of individual sources. In contrast to those in previous searches with IceCube, the populations investigated contain up to hundreds of sources, the largest one being the entire blazar sample in the 2LAC catalog. No significant excess is observed, and upper limits for the cumulative flux from these populations are obtained. These constrain the maximum contribution of 2LAC blazars to the observed astrophysical neutrino flux to 27% or less between around 10 TeV and 2 PeV, assuming the equipartition of flavors on Earth and a single power-law spectrum with a spectral index of −2.5. We can still exclude the fact that 2LAC blazars (and their subpopulations) emit more than 50% of the observed neutrinos up to a spectral index as hard as −2.2 in the same energy range. Our result takes into account the fact that the neutrino source count distribution is unknown, and it does not assume strict proportionality of the neutrino flux to the measured 2LAC γ -ray signal for each source. Additionally, we constrain recent models for neutrino emission by blazars.

  20. Water quality and hydrology of the Lac Vieux Desert watershed, Gogebic County, Michigan, and Vilas County, Wisconsin, 2002-04

    Science.gov (United States)

    Weaver, T.L.; Neff, B.P.; Ellis, J.M.

    2005-01-01

    Lac Vieux Desert is a prominent 6.6 square-mile lake that straddles the Michigan-Wisconsin border and forms the headwaters of the Wisconsin River. For generations, the Lac Vieux Desert Band of Lake Superior Chippewa Indians have used Lac Vieux Desert and the surrounding area for growing and harvesting wild rice, and hunting and fishing. The Lac Vieux Desert Band is concerned about the impact of lake-stage regulation on hydrology and ecology, and the impact on water quality of development along and near the shore, and recreational watercraft use and sport fishing. In 2005, the U.S. Geological Survey completed a water-resources investigation of the Lac Vieux Desert watershed in cooperation with the Lac Vieux Desert Band of Lake Superior Chippewa Indians.Water quality of Lac Vieux Desert is typical of many lakes in the northern United States. Trophic State Index calculations classify Lac Vieux Desert as a highly productive eutrophic lake. The pH of water in Lac Vieux Desert ranged from 6.5 to 9.5, and specific conductance ranged from 62 to 114 µs/cm. Chloride concentration was less than 1.5 mg/L, indicating little effect from septic-tank or road-salt input. Results indicate that the water can be classified as soft, with hardness concentrations reported as calcium carbonate ranging from 29 to 49 mg/L. Concentrations of calcium, magnesium, chloride, and other dissolved solids ranged from 47 to 77 mg/L. Alkalinity of Lac Vieux Desert ranged from 27 to 38 mg/L.Pervasive aquatic blooms, including a bloom noted during the September 2003 sampling, are apparently common in late summer. Biological productivity at Lac Vieux Desert does not appear to have changed appreciably between 1973 and 2004. In the current study, total phosphorus concentrations ranged from 0.01 to 0.064 mg/L and dissolved nitrite plus nitrate nitrogen concentrations ranged from at, or below detection limit to 0.052 mg/L. Overabundance of nutrients in Lac Vieux Desert, particularly nitrogen and phosphorus

  1. Enzymatic Synthesis of N-Acetyllactosamine (LacNAc Type 1 Oligomers and Characterization as Multivalent Galectin Ligands

    Directory of Open Access Journals (Sweden)

    Thomas Fischöder

    2017-08-01

    Full Text Available Repeats of the disaccharide unit N-acetyllactosamine (LacNAc occur as type 1 (Galβ1, 3GlcNAc and type 2 (Galβ1, 4GlcNAc glycosylation motifs on glycoproteins and glycolipids. The LacNAc motif acts as binding ligand for lectins and is involved in many biological recognition events. To the best of our knowledge, we present, for the first time, the synthesis of LacNAc type 1 oligomers using recombinant β1,3-galactosyltransferase from Escherichia coli and β1,3-N-acetylglucosaminyltranferase from Helicobacter pylori. Tetrasaccharide glycans presenting LacNAc type 1 repeats or LacNAc type 1 at the reducing or non-reducing end, respectively, were conjugated to bovine serum albumin as a protein scaffold by squarate linker chemistry. The resulting multivalent LacNAc type 1 presenting neo-glycoproteins were further studied for specific binding of the tumor-associated human galectin 3 (Gal-3 and its truncated counterpart Gal-3∆ in an enzyme-linked lectin assay (ELLA. We observed a significantly increased affinity of Gal-3∆ towards the multivalent neo-glycoprotein presenting LacNAc type 1 repeating units. This is the first evidence for differences in glycan selectivity of Gal-3∆ and Gal-3 and may be further utilized for tracing Gal-3∆ during tumor progression and therapy.

  2. USING THE METHODS OF WAVELET ANALYSIS AND SINGULAR SPECTRUM ANALYSIS IN THE STUDY OF RADIO SOURCE BL LAC

    OpenAIRE

    Donskykh, G. I.; Ryabov, M. I.; Sukharev, A. I.; Aller, M.

    2014-01-01

    We investigated the monitoring data of extragalactic source BL Lac. This monitoring was held withUniversityofMichigan26-meter radio  telescope. To study flux density of extragalactic source BL Lac at frequencies of 14.5, 8 and 4.8 GHz, the wavelet analysis and singular spectrum analysis were used. Calculating the integral wavelet spectra allowed revealing long-term  components  (~7-8 years) and short-term components (~ 1-4 years) in BL Lac. Studying of VLBI radio maps (by the program Mojave) ...

  3. Effet des conditions climatiques sur le niveau du lac Sidi Ali (Moyen Atlas, Maroc)

    OpenAIRE

    Sayad, Ahmed; Chakiri, Saïd; Martin, Claude; Bejjaji, Zohra; Echarfaoui, Hassan

    2012-01-01

    Le lac Sidi Ali est un lac naturel d'altitude (2070-2080 m), sans exutoire superficiel, déterminé par le barrage d'une coulée basaltique. Doté d'un bassin versant apparent de 15,6 km2, il est alimenté par des eaux de ruissellement et par des sources karstiques. Son niveau subit des variations très fortes, annuelles et interannuelles, sous le contrôle des conditions climatiques, et en particulier des pluies et de l'évapotranspiration. Les périodes de sécheresse qui ont marqué les trois dernièr...

  4. Search for relation between flares and photometric variability outside of flares in EV Lac

    International Nuclear Information System (INIS)

    Rojzman, G.Sh.

    1984-01-01

    The observations of the flare star EV Lac in July-September 1981 have confirmed the existence of photometric variability outside the flares during the night. It was found that, as a rule, a slow increase of brightness in U and B bands during 1-2 hours preceded the flares. It is suggested that the variability outside the flares is the result of the variability of chpomospheric emission lines and continuum that are emitted by the chromospheric preflare formations

  5. A source of artifact in the lacZ reversion assay in Escherichia coli.

    Science.gov (United States)

    Hoffmann, George R; Gray, Carol L; Lange, Paulina B; Marando, Christie I

    2015-06-01

    The lacZ reversion assay in Escherichia coli measures point mutations that occur by specific base substitutions and frameshift mutations. The tester strains cannot use lactose as a carbon source (Lac(-)), and revertants are easily detected by growth on lactose medium (Lac(+)). Six strains identify the six possible base substitutions, and five strains measure +G, -G, -CG, +A and -A frameshifts. Strong mutagens give dose-dependent increases in numbers of revertants per plate and revertant frequencies. Testing compounds that are arguably nonmutagens or weakly mutagenic, we often noted statistically significant dose-dependent increases in revertant frequency that were not accompanied by an absolute increase in numbers of revertants. The increase in frequency was wholly ascribable to a declining number of viable cells owing to toxicity. Analysis of the conditions revealed that the frequency of spontaneous revertants is higher when there are fewer viable cells per plate. The phenomenon resembles "adaptive" or "stress" mutagenesis, whereby lactose revertants accumulate in Lac(-) bacteria under starvation conditions in the absence of catabolite repression. Adaptive mutation is observed after long incubation and might be expected to be irrelevant in a standard assay using 48-h incubation. However, we found that elevated revertant frequencies occur under typical assay conditions when the bacterial lawn is thin, and this can cause increases in revertant frequency that mimic chemical mutagenesis when treatments are toxic but not mutagenic. Responses that resemble chemical mutagenesis were observed in the absence of mutagenic treatment in strains that revert by different frameshift mutations. The magnitude of the artifact is affected by cell density, dilution, culture age, incubation time, catabolite repression and the age and composition of media. Although the specific reversion assay is effective for quickly distinguishing classes of mutations induced by potent mutagens, its

  6. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d\\'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

  7. Évaluation du niveau de pollution par les métaux lourds des lacs ...

    African Journals Online (AJOL)

    La présente étude a pour objectif principal d'évaluer le niveau de pollution métallique des lacs Bini et Dang (Ngaoundéré, Cameroun) à travers l'analyse des eaux et des sédiments de surface. La concentration des métaux lourds (Ni, Cr, Fe, Pb, Cd, Zn) a été mesurée par spectrophotométrie d'absorption atomique.

  8. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Administrateur

    Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

  9. Archive of Geosample Data and Information from the University of Minnesota National Lacustrine Core Repository (LacCore)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Lacustrine Core Repository (LacCore), operated by the University of Minnesota is a partner in the Index to Marine and Lacustrine Geological Samples...

  10. Variabilité journalière de la qualité physico-chimique du lac M'koa ...

    African Journals Online (AJOL)

    d'enrichissement en matières organique, azote et phosphore capables d'influer sur la teneur de saturation en oxygène dissous. La Figure 4 montre des lavandiers communément appelés "fanico" exerçant leur activité quotidienne au lac. Cette activité est source d'enrichissement des eaux du lac. M'koa en phosphore et ...

  11. Laccase 1 gene from Plutella xylostella (PxLac1) and its functions in humoral immune response.

    Science.gov (United States)

    Wang, Ze-Hua; Hu, Rong-Min; Ye, Xi-Qian; Huang, Jian-Hua; Chen, Xue-Xin; Shi, Min

    Laccase (EC 1.10.3.2) is a phenoloxidase found in many insect species. The Laccase 1 gene from Plutella xylostella (PxLac1) was cloned, and its expression patterns and functions were determined using qPCR and RNAi methods. The results showed that the expression levels of PxLac1 were consistently high in all larval stages, and the most abundant was in the midgut during the 4th instar stage. Moreover, the expression of PxLac1 was up-regulated in response to bacterial infection, and decreased 24 h after being parasitized by Cotesia vestalis. Further analyses indicated that the effect of parasitization on PxLac1 was induced by active C. vestalis Bracovirus (CvBV). Haemocyte-free hemolymph phenoloxidase (PO) activity was suppressed when PxLac1 was treated with RNAi. Our results provide evidence for a connection between the Laccase 1 gene and insect immunity, and revealed that parasitoid polydnavirus suppresses host PO activity via PxLac1 regulation. Copyright © 2018. Published by Elsevier Ltd.

  12. Seven-Year Multi-Colour Optical Monitoring of BL Lacertae Object ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... 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 ...

  13. PG 1553 + 11 - A bright optically selected BL Lacertae object

    International Nuclear Information System (INIS)

    Falomo, R.; Treves, A.

    1990-01-01

    A detailed study of the bright optically selected BL Lac object PG 1553 + 11 is presented. UV observations, obtained during a high state of the source, together with simultaneous optical spectrophotometry and near-IR photometry, allow the spectral flux distribution to be examined from 8 x 10 to the 13th to 2.5 x 10 to the 15th Hz. This distribution is compared with that derived from quasi-simultaneous observations obtained when the source was a factor of about 3 fainter. It is found that, in the higher state, the spectrum can be described by two power laws connected by a break at about 10 to the 15th Hz, while in the low state the shape is more complex. The overall spectrum of the object is compared with the average energy distribution of X-ray and radio-selected BL Lac objects, showing that it is closer to the former class. 25 refs

  14. Impact of seeing and host galaxy into the analysis of photo-polarimetric microvariability in blazars. Case study of the nearby blazars 1ES 1959+650 and HB89 2201+044

    Science.gov (United States)

    Sosa, M. S.; von Essen, C.; Andruchow, I.; Cellone, S. A.

    2017-11-01

    Blazars, a type of Active Galactic Nuclei, present a particular orientation of their jets close to the line of sight. Their radiation is thus relativistically beamed, giving rise to extreme behaviors, specially strong variability on very short timescales (I.e., microvariability). Here we present simultaneous photometric and polarimetric observations of two relatively nearby blazars, 1ES 1959+650 and HB89 2201+044, that were obtained using the Calar Alto Faint Object Spectrograph mounted at the 2.2 m telescope in Calar Alto, Spain. An outstanding characteristic of these two blazars is the presence of well resolved host galaxies. This particular feature allows us to produce a study of their intrinsic polarization, a measurement of the polarization state of the galactic nucleus unaffected by the host galaxy. To carry out this work, we computed photometric fluxes from which we calculated the degree and orientation of the blazars polarization. Then, we analyzed the depolarizing effect introduced by the host galaxy with the main goal to recover the intrinsic polarization of the galactic nucleus, carefully taking into consideration the spurious polarimetric variability introduced by changes in seeing along the observing nights. We find that the two blazars do not present intra-night photo-polarimetric variability, although we do detect a significant inter-night variability. Comparing polarimetric values before and after accounting for the host galaxies, we observe a significant difference in the polarization degree of about 1% in the case of 1ES 1959+650, and 0.3% in the case of HB89 2201+044, thus evidencing the non-negligible impact introduced by the host galaxies. We note that this host galaxy effect depends on the waveband, and varies with changing seeing conditions, so it should be particularly considered when studying frequency-dependent polarization in blazars. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated

  15. Effector Overlap between the lac and mel Operons of Escherichia coli: Induction of the mel Operon with β-Galactosides.

    Science.gov (United States)

    Narang, Atul; Oehler, Stefan

    2017-05-01

    The lac (lactose) operon (which processes β-galactosides) and the mel (melibiose) operon (which processes α-galactosides) of Escherichia coli have a close historical connection. A number of shared substrates and effectors of the permeases and regulatory proteins have been reported over the years. Until now, β-thiogalactosides like TMG (methyl-β-d-thiogalactopyranoside) and IPTG (isopropyl-β-d-thiogalactopyranoside) have not generally been considered to be inducers of the mel operon. The same is true for β-galactosides such as lactose [β-d-galactopyranosyl-(1→4)-d-glucose], which is a substrate but is not itself an inducer of the lac operon. This report shows that all three sugars can induce the mel operon significantly when they are accumulated in the cell by Lac permease. Strong induction by β-thiogalactosides is observed in the presence of Lac permease, and strong induction by lactose (more than 200-fold) is observed in the absence of β-galactosidase. This finding calls for reevaluation of TMG uptake experiments as assays for Lac permease that were performed with mel + strains. IMPORTANCE The typical textbook picture of bacterial operons is that of stand-alone units of genetic information that perform, in a regulated manner, well-defined cellular functions. Less attention is given to the extensive interactions that can be found between operons. Well-described examples of such interactions are the effector molecules shared by the lac and mel operons. Here, we show that this set has to be extended to include β-galactosides, which have been, until now, considered not to effect the expression of the mel operon. That they can be inducers of the mel operon as well as the lac operon has not been noted in decades of research because of the Escherichia coli genetic background used in previous studies. Copyright © 2017 American Society for Microbiology.

  16. Object and Objective Lost?

    DEFF Research Database (Denmark)

    Lopdrup-Hjorth, Thomas

    2015-01-01

    This paper explores the erosion and problematization of ‘the organization’ as a demarcated entity. Utilizing Foucault's reflections on ‘state-phobia’ as a source of inspiration, I show how an organization-phobia has gained a hold within Organization Theory (OT). By attending to the history...... 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......, organizations as distinct entities have been rendered so problematic that they have gradually come to be removed from the center of OT. The costs of this have been rather significant. Besides undermining the grounds that gave OT intellectual credibility and legitimacy to begin with, the organization-phobia...

  17. The SOS-LUX-LAC-FLUORO-Toxicity-test on the International Space Station (ISS).

    Science.gov (United States)

    Rabbow, E; Rettberg, P; Baumstark-Khan, C; Horneck, G

    2003-01-01

    In the 21st century, an increasing number of astronauts will visit the International Space Station (ISS) for prolonged times. Therefore it is of utmost importance to provide necessary basic knowledge concerning risks to their health and their ability to work on the station and during extravehicular activities (EVA) in free space. It is the aim of one experiment of the German project TRIPLE-LUX (to be flown on the ISS) to provide an estimation of health risk resulting from exposure of the astronauts to the radiation in space inside the station as well as during extravehicular activities on one hand, and of exposure of astronauts to unavoidable or as yet unknown ISS-environmental genotoxic substances on the other. The project will (i) provide increased knowledge of the biological action of space radiation and enzymatic repair of DNA damage, (ii) uncover cellular mechanisms of synergistic interaction of microgravity and space radiation and (iii) examine the space craft milieu with highly specific biosensors. For these investigations, the bacterial biosensor SOS-LUX-LAC-FLUORO-Toxicity-test will be used, combining the SOS-LUX-Test invented at DLR Germany (Patent) with the commercially available LAC-FLUORO-Test. The SOS-LUX-Test comprises genetically modified bacteria transformed with the pBR322-derived plasmid pPLS-1. This plasmid carries the promoterless lux operon of Photobacterium leiognathi as a reporter element under control of the DNA-damage dependent SOS promoter of ColD as sensor element. This system reacts to radiation and other agents that induce DNA damages with a dose dependent measurable emission of bioluminescence of the transformed bacteria. The analogous LAC-FLUORO-Test has been developed for the detection of cellular responses to cytotoxins. It is based on the constitutive expression of green fluorescent protein (GFP) mediated by the bacterial protein expression vector pGFPuv (Clontech, Palo Alto, USA). In response to cytotoxic agents, this system

  18. The effect of stochasticity on the lac operon: an evolutionary perspective.

    Directory of Open Access Journals (Sweden)

    Milan van Hoek

    2007-06-01

    Full Text Available The role of stochasticity on gene expression is widely discussed. Both potential advantages and disadvantages have been revealed. In some systems, noise in gene expression has been quantified, in among others the lac operon of Escherichia coli. Whether stochastic gene expression in this system is detrimental or beneficial for the cells is, however, still unclear. We are interested in the effects of stochasticity from an evolutionary point of view. We study this question in the lac operon, taking a computational approach: using a detailed, quantitative, spatial model, we evolve through a mutation-selection process the shape of the promoter function and therewith the effective amount of stochasticity. We find that noise values for lactose, the natural inducer, are much lower than for artificial, nonmetabolizable inducers, because these artificial inducers experience a stronger positive feedback. In the evolved promoter functions, noise due to stochasticity in gene expression, when induced by lactose, only plays a very minor role in short-term physiological adaptation, because other sources of population heterogeneity dominate. Finally, promoter functions evolved in the stochastic model evolve to higher repressed transcription rates than those evolved in a deterministic version of the model. This causes these promoter functions to experience less stochasticity in gene expression. We show that a high repression rate and hence high stochasticity increases the delay in lactose uptake in a variable environment. We conclude that the lac operon evolved such that the impact of stochastic gene expression is minor in its natural environment, but happens to respond with much stronger stochasticity when confronted with artificial inducers. In this particular system, we have shown that stochasticity is detrimental. Moreover, we demonstrate that in silico evolution in a quantitative model, by mutating the parameters of interest, is a promising way to unravel

  19. Thermal cracking in Lac du Bonnet granite during slow heating to 205 degrees celsius

    International Nuclear Information System (INIS)

    Chernis, P.J.; Robertson, P.B.

    1993-09-01

    Acoustic emissions (AE) were recorded as drill core samples of Lac du Bonnet granite were slowly heated to between 66 and 205 degrees celsius to evaluate the effects of temperature on the properties of rock samples. Longitudinal and shear velocities of the samples were measured, and Young's moduli, shear moduli and Poisson's ratios were calculated. No significant AE activity was detected until temperatures reached approximately 73-80 degrees celsius. Above this 'threshold' temperature, calculated rock properties decreased, and at 205 degrees celsius calculated Young's modulus, shear modulus, and Poisson's ratio were reduced by 30, 26, and 29% respectively

  20. The diluvial rains of Saguenay-Lac-Saint-Jean : status one year after

    International Nuclear Information System (INIS)

    Henri, N.; Beauchemin, G.; Alonso, M.; Gelinas, M.

    1997-01-01

    The status of damages and reconstruction in the Saguenay-Lac-Saint-Jean region, one year after the catastrophic torrential rain storm of July 1996 was presented. Numerous detailed maps and photographs of the principal washed-out, destroyed and damaged regions were presented, along with maps and photographs of the same areas after reconstruction, repair and landscaping. The maps show the different river beds, urban, and rural districts that were subjected to the catastrophic washouts, landslides and soil collapses. The report also includes a summary of the repair costs by municipal regions and the financial aid received by the region to help in the reconstruction effort. tabs., figs

  1. Evaluation of critical indicators in the process of acquiring supplies and services LAC-UFPE

    Science.gov (United States)

    Caetano, V. F.; Ferreira, C. V.; dos Santos, M. J.; Honorato, F. A.

    2015-01-01

    In laboratories linked to public universities and accredited by the NBR ISO/IEC 17025, to meet efficiently item 4.6 (procurement of supplies and services) is a challenge that can be accomplished by programming based on historical purchases and services. In this study, we evaluated the critical procurement items to meet the quality management system of the LAC-UFPE: reagents, certified reference material, of equipment parts, maintenance and calibration of equipment and instruments. It was found that the most critical item is the certified reference material, the purchase or repair of which must be expedited within 125 days prior to the receipt to occur within the desired period.

  2. Hopf Bifurcation and Delay-Induced Turing Instability in a Diffusive lac Operon Model

    Science.gov (United States)

    Cao, Xin; Song, Yongli; Zhang, Tonghua

    In this paper, we investigate the dynamics of a lac operon model with delayed feedback and diffusion effect. If the system is without delay or the delay is small, the positive equilibrium is stable so that there are no spatial patterns formed; while the time delay is large enough the equilibrium becomes unstable so that rich spatiotemporal dynamics may occur. We have found that time delay can not only incur temporal oscillations but also induce imbalance in space. With different initial values, the system may have different spatial patterns, for instance, spirals with one head, four heads, nine heads, and even microspirals.

  3. Geology and age of the Lac a la Perdrix fenite, southern Gatineau district, Quebec

    Energy Technology Data Exchange (ETDEWEB)

    Hogarth, D D [Ottawa Univ., ON (Canada). Dept. of Geology; VanBreemen, O [Geological Survey of Canada, Ottawa, ON (Canada)

    1997-12-31

    The Lac a Ia Perdrix fenite lies in the Central Metasedimentary Belt of the Grenville Province. This 30 m wide fenite, adjacent to a narrow calciocarbonatite sill, replaces diopside-oligoclase gneiss and is composed of magnesio-arfvedsonite, aegirine, microcline, albite, and fluorapatite. Near the contact with carbonatite, it contains appreciable monazite and barite whereas aegirine virtually disappears. Fenitization probably took place early in the igneous stage of carbonatite development. A Pb/U monazite age of 1026 {+-} 2 Ma is thought to date fenite formation. Together with published data, this age shows that carbonatite intruded metamorphic rocks near the close of the Grenville Orogeny. (author). 33 refs., 4 tabs., 5 figs.

  4. Analysis of spontaneous deletions and gene amplification in the lac region of Escherichia coli

    International Nuclear Information System (INIS)

    Albertini, A.M.; Hofer, M.; Calos, M.P.; Tlsty, T.D.; Miller, J.H.

    1983-01-01

    Spontaneous rearrangements, such as large deletions and duplications, have important implications for the structure of the genome. It is therefore of great interest to analyze these events at the molecular level. We have constructed derivatives of a lacI-Z fusion strain, which allow us to study deletions in a more systematic manner than was previously possible. These derivatives have been used to investigate how frequently larger deletions (> 700 bp) occur between short homologies on both recA and recA - strains and to determine the effect of the lengths of the short homologies and of the distance between homologies on the frequency of deletion formation. 38 references, 11 figures

  5. Fish communities in man-made lakes = Peuplements ichtyologiques des lacs de barrage

    OpenAIRE

    Jackson, P.N.B.; Marshall, B.E.; Paugy, Didier

    1988-01-01

    Il existe actuellement des réservoirs artificiels sur de nombreuses rivières africaines. Leur construction a modifié les conditions écologiques (facteurs édaphiques, apports en éléments nutritifs) et changé la composition des peuplements ichtyologiques ... Le barrage lui-même peut être un obstacle pour des poissons tels que les anguilles ou les mulets migrants depuis la mer et entraîner la disparition des espèces en amont ... Les lacs de barrage ont une vaste zone pélagique favorable au déve...

  6. High-level expression of Bacillus naganoensis pullulanase from recombinant Escherichia coli with auto-induction: effect of lac operator.

    Directory of Open Access Journals (Sweden)

    Yao Nie

    Full Text Available Pullulanase plays an important role in specific hydrolysis of branch points in amylopectin and is generally employed as an important enzyme in starch-processing industry. So far, however, the production level of pullulanase is still somewhat low from wide-type strains and even heterologous expression systems. Here the gene encoding Bacillus naganoensis pullulanase was amplified and cloned. For expression of the protein, two recombinant systems, Escherichia coli BL21(DE3/pET-20b(+-pul and E. coli BL21(DE3/pET-22b(+-pul, were constructed, both bearing T7 promoter and signal peptide sequence, but different in the existance of lac operator and lacI gene encoding lac repressor. Recombinant pullulanase was initially expressed with the activity of up to 14 U/mL by E. coli BL21(DE3/pET-20b(+-pul with IPTG induction in LB medium, but its expression level reduced continually with the extension of cryopreservation time and basal expression was observed. However, E. coli BL21(DE3/pET-22b(+-pul , involving lac operator downstream of T7 promoter to regulate foreign gene transcription, exhibited pullulanase activity consistently without detected basal expression. By investigating the effect of lac operator, basal expression of foreign protein was found to cause expression instability and negative effect on production of target protein. Thus double-repression strategy was proposed that lac operators in both chromosome and plasmid were bound with lac repressor to repress T7 RNA polymerase synthesis and target protein expression before induction. Consequently, the total activity of pullulanase was remarkably increased to 580 U/mL with auto-induction by lac operator-involved E. coli BL21(DE3/pET-22b(+-pul. When adding 0.6% glycine in culture, the extracellular production of pullulanase was significantly improved with the extracellular activity of 502 U/mL, which is a relatively higher level achieved to date for extracellular production of pullulanase. The

  7. Gtl2lacZ, an insertional mutation on mouse chromosome 12 with parental origin-dependent phenotype.

    Science.gov (United States)

    Schuster-Gossler, K; Simon-Chazottes, D; Guenet, J L; Zachgo, J; Gossler, A

    1996-01-01

    We have produced a transgenic mouse line, Gtl2lacZ (Gene trap locus 2), that carries an insertional mutation with a dominant modified pattern of inheritance:heterozygous Gtl2lacZ mice that inherited the transgene from the father show a proportionate dwarfism phenotype, whereas the penetrance and expressivity of the phenotype is strongly reduced in Gtl2lacZ mice that inherited the transgene from the mother. On a mixed genetic background this pattern of inheritance was reversible upon transmission of the transgene through the germ line of the opposite sex. On a predominantly 129/Sv genetic background, however, transgene passage through the female germ line modified the transgene effect, such that the penetrance of the mutation was drastically reduced and the phenotype was no longer obvious after subsequent male germ line transmission. Expression of the transgene, however, was neither affected by genetic background nor by parental legacy. Gtl2lacZ maps to mouse Chromosome 12 in a region that displays imprinting effects associated with maternal and paternal disomy. Our results suggest that the transgene insertion in Gtl2lacZ mice affects an endogenous gene(s) required for fetal and postnatal growth and that this gene(s) is predominantly paternally expressed.

  8. Local gene regulation details a recognition code within the LacI transcriptional factor family.

    Directory of Open Access Journals (Sweden)

    Francisco M Camas

    2010-11-01

    Full Text Available The specific binding of regulatory proteins to DNA sequences exhibits no clear patterns of association between amino acids (AAs and nucleotides (NTs. This complexity of protein-DNA interactions raises the question of whether a simple set of wide-coverage recognition rules can ever be identified. Here, we analyzed this issue using the extensive LacI family of transcriptional factors (TFs. We searched for recognition patterns by introducing a new approach to phylogenetic footprinting, based on the pervasive presence of local regulation in prokaryotic transcriptional networks. We identified a set of specificity correlations--determined by two AAs of the TFs and two NTs in the binding sites--that is conserved throughout a dominant subgroup within the family regardless of the evolutionary distance, and that act as a relatively consistent recognition code. The proposed rules are confirmed with data of previous experimental studies and by events of convergent evolution in the phylogenetic tree. The presence of a code emphasizes the stable structural context of the LacI family, while defining a precise blueprint to reprogram TF specificity with many practical applications.

  9. In vitro transcription accurately predicts lac repressor phenotype in vivo in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Matthew Almond Sochor

    2014-07-01

    Full Text Available A multitude of studies have looked at the in vivo and in vitro behavior of the lac repressor binding to DNA and effector molecules in order to study transcriptional repression, however these studies are not always reconcilable. Here we use in vitro transcription to directly mimic the in vivo system in order to build a self consistent set of experiments to directly compare in vivo and in vitro genetic repression. A thermodynamic model of the lac repressor binding to operator DNA and effector is used to link DNA occupancy to either normalized in vitro mRNA product or normalized in vivo fluorescence of a regulated gene, YFP. An accurate measurement of repressor, DNA and effector concentrations were made both in vivo and in vitro allowing for direct modeling of the entire thermodynamic equilibrium. In vivo repression profiles are accurately predicted from the given in vitro parameters when molecular crowding is considered. Interestingly, our measured repressor–operator DNA affinity differs significantly from previous in vitro measurements. The literature values are unable to replicate in vivo binding data. We therefore conclude that the repressor-DNA affinity is much weaker than previously thought. This finding would suggest that in vitro techniques that are specifically designed to mimic the in vivo process may be necessary to replicate the native system.

  10. Purified reconstituted lac carrier protein from Escherichia coli is fully functional.

    Science.gov (United States)

    Viitanen, P; Garcia, M L; Kaback, H R

    1984-03-01

    Proteoliposomes reconstituted with lac carrier protein purified from the plasma membrane of Escherichia coli catalyze each of the translocation reactions typical of the beta-galactoside transport system (i.e., active transport, counterflow, facilitated influx and efflux) with turnover numbers and apparent Km values comparable to those observed in right-side-out membrane vesicles. Furthermore, detailed kinetic studies show that the reconstituted system exhibits properties analogous to those observed in membrane vesicles. Imposition of a membrane potential (delta psi, interior negative) causes a marked decrease in apparent Km (by a factor of 7 to 10) with a smaller increase in Vmax (approximately equal to 3-fold). At submaximal values of delta psi, the reconstituted carrier exhibits biphasic kinetics, with one component manifesting the kinetic parameters of active transport and the other exhibiting the characteristics of facilitated diffusion. Finally, at low lactose concentrations, the initial velocity of influx varies linearly with the square of the proton electro-chemical gradient. The results provide quantitative support for the contention that a single polypeptide species, the product of the lac y gene, is responsible for each of the transport reactions typical of the beta-galactoside transport system.

  11. Dynamics and bistability in a reduced model of the lac operon

    Science.gov (United States)

    Yildirim, Necmettin; Santillán, Moisés; Horike, Daisuke; Mackey, Michael C.

    2004-06-01

    It is known that the lac operon regulatory pathway is capable of showing bistable behavior. This is an important complex feature, arising from the nonlinearity of the involved mechanisms, which is essential to understand the dynamic behavior of this molecular regulatory system. To find which of the mechanisms involved in the regulation of the lac operon is the origin of bistability, we take a previously published model which accounts for the dynamics of mRNA, lactose, allolactose, permease and β-galactosidase involvement and simplify it by ignoring permease dynamics (assuming a constant permease concentration). To test the behavior of the reduced model, three existing sets of data on β-galactosidase levels as a function of time are simulated and we obtain a reasonable agreement between the data and the model predictions. The steady states of the reduced model were numerically and analytically analyzed and it was shown that it may indeed display bistability, depending on the extracellular lactose concentration and growth rate.

  12. Intelligent Local Avoided Collision (iLAC) MAC Protocol for Very High Speed Wireless Network

    Science.gov (United States)

    Hieu, Dinh Chi; Masuda, Akeo; Rabarijaona, Verotiana Hanitriniala; Shimamoto, Shigeru

    Future wireless communication systems aim at very high data rates. As the medium access control (MAC) protocol plays the central role in determining the overall performance of the wireless system, designing a suitable MAC protocol is critical to fully exploit the benefit of high speed transmission that the physical layer (PHY) offers. In the latest 802.11n standard [2], the problem of long overhead has been addressed adequately but the issue of excessive colliding transmissions, especially in congested situation, remains untouched. The procedure of setting the backoff value is the heart of the 802.11 distributed coordination function (DCF) to avoid collision in which each station makes its own decision on how to avoid collision in the next transmission. However, collision avoidance is a problem that can not be solved by a single station. In this paper, we introduce a new MAC protocol called Intelligent Local Avoided Collision (iLAC) that redefines individual rationality in choosing the backoff counter value to avoid a colliding transmission. The distinguishing feature of iLAC is that it fundamentally changes this decision making process from collision avoidance to collaborative collision prevention. As a result, stations can avoid colliding transmissions with much greater precision. Analytical solution confirms the validity of this proposal and simulation results show that the proposed algorithm outperforms the conventional algorithms by a large margin.

  13. Hydrogeologic characteristics of domains of sparsely fractured rock in the granitic Lac Du Bonnet Batholith, southeastern Manitoba, Canada

    International Nuclear Information System (INIS)

    Stevenson, D.R.; Kozak, E.T.; Davison, C.C.; Gascoyne, M.; Broadfoot, R.A.

    1996-06-01

    The hydrogeologic characteristics of the granitic Lac du Bonnet batholith in southeastern Manitoba have been studied since 1978, as part of AECL's program to assess the concept of disposing of Canada's nuclear fuel waste deep within plutonic rocks of the Canadian Shield (Davison et al. 1994a). These studies have included an extensive program of drilling, logging, testing, sampling and monitoring in 19 deep surface boreholes drilled at Grid areas located across the Lac du Bonnet batholith, at the Whiteshell Laboratory (WL), and in surface and underground boreholes at the Underground Research Laboratory (URL). Based on these investigations domains of low permeability, sparsely fractured rock (SFR) have been identified in the Lac du Bonnet batholith

  14. Lipofection of rabbit chondrocytes and long lasting expression of a lacZ reporter system in alginate beads.

    Science.gov (United States)

    Stöve, J; Fiedler, J; Huch, K; Günther, K-P; Puhl, W; Brenner, R

    2002-03-01

    Our aim was to investigate the maintenance of the transfection status of non-viral transfected chondrocytes in an alginate culture system. Chondrocytes harvested from rabbit knees were isolated by sequential digestion and cultivated in monolayer culture. At 60-70% cell density, chondrocytes were transfected with different transfection systems (FuGENE6, CaCl2, Lipofectin). A lac Z expression vector (pcDNA 3.1/Myc-His+ lacZ) was used as a reporter system. In order to improve transfection rates, hyaluronidase (4 U/ml) was used prior and during the transfection procedure. Thereafter, transfected cells were either kept in monolayer culture or embedded in alginate beads and kept in culture for up to the next 30 weeks. Transfection efficiency was maximal using FuGENE6TM/DNA at a ratio of 3:2 and hyaluronidase (4 U/ml). Transfection efficiency reached up to 40.8% (+/- 3.2%) after 36 h. In alginate beads lac Z positive cells declined to 8.5% +/- 3.3% after 4 weeks and to 4.6% +/- 3.2% after 12 weeks of culturing. After 30 weeks 3% of chondrocytes still expressed lac Z. In contrast, during culturing in monolayer, no lac Z expression was detectable after 4 weeks. Differentiation status of the chondrocytes was confirmed by histology and immunohistochemistry methods. After successful gene transfer to rabbit chondrocytes the alginate system made it possible to culture lipofected chondrocytes phenotypically stable. Genetically engineered chondrocytes express the lac Z reporter gene over a period of at least 30 weeks. This transfection and culture system provides a promising tool to further investigate the over-expression of growth factors and enzyme inhibitors. Copyright 2002 OsteoArthritis Research Society International.

  15. lacZ transduced human breast cancer xenografts as an in vivo model for the study of invasion and metastasis

    DEFF Research Database (Denmark)

    Brünner, N; Thompson, E W; Spang-Thomsen, M

    1992-01-01

    in the animals by usual histological procedures would require extensive sectioning of the whole animal. To overcome this problem, we transduced human breast cancer cells with a replication-defective Moloney murine leukaemia retroviral vector (M-MuLV) containing both neoR (neomycin resistance) and lacZ genes...... but not the surrounding mouse tissue on either whole tissue blocks or histological sections. The staining procedure was highly sensitive, allowing detection of microfoci of human cancer cells, and quantitative estimation of the metastatic capacity of the cells. These results indicate that lacZ transduction of human...

  16. Characterization of pLAC1, a cryptic plasmid isolated from Lactobacillus acidipiscis and comparative analysis with its related plasmids.

    Science.gov (United States)

    Asteri, Ioanna-Areti; Papadimitriou, Konstantinos; Boutou, Effrossyni; Anastasiou, Rania; Pot, Bruno; Vorgias, Constantinos E; Tsakalidou, Effie

    2010-07-15

    The pLAC1 plasmid of Lactobacillus acidipiscis ACA-DC 1533, a strain isolated from traditional Kopanisti cheese, was characterised. Nucleotide sequence analysis revealed a circular molecule of 3478bp with a G+C content of 37.2%. Ab initio annotation indicated four putative open reading frames (orfs). orf1 and orf4 were found to encode a replication initiation protein (Rep) and a mobilization protein (Mob), respectively. The deduced products of orf2 and orf3 revealed no significant homology to other known proteins. However, in silico examination of the plasmid sequence supported the existence of a novel operon that includes rep, orf2 and orf3 in pLAC1 and that this operon is highly conserved also in plasmids pLB925A02, pSMA23, pLC88 and pC7. RT-PCR experiments allowed us to verify that these three genes are co-transcribed as a single polycistronic mRNA species. Furthermore, phylogenetic analysis of pLAC1 Rep and Mob proteins demonstrated that they may have derived from different plasmid origins, suggesting that pLAC1 is a product of a modular evolution process. Comparative analysis of full length nucleotide sequences of pLAC1 and related Lactobacillus plasmids showed that pLAC1 shares a very similar replication backbone with pLB925A02, pSMA23 and pLC88. In contrast, mob of pLAC1 was almost identical with the respective gene of plasmids pLAB1000, pLB4 and pPB1. These findings lead to the conclusion that pLAC1 acquired mob probably via an ancestral recombination event. Our overall work highlights the importance of characterizing plasmids deriving from non-starter 'wild' isolates in order to better appreciate plasmid divergence and evolution of lactic acid bacteria. 2010 Elsevier B.V. All rights reserved.

  17. A fire history derived from Pinus resinosa Ait. for the Islands of Eastern Lac La Croix, Minnesota, USA.

    Science.gov (United States)

    Johnson, Lane B; Kipfmueller, Kurt F

    2016-06-01

    We reconstructed fire occurrence near a fur-trade era canoe travel corridor (used ca. 1780-1802) in the Quetico-Superior region west of Lake Superior to explore the possibility of human influence on pre-fire suppression rates of fire occurrence. Our research objectives were to (1) examine the spatial and temporal patterns of fire in the study area, (2) test fires' strength of association with regional drought, and (3) assess whether reconstructed fire frequencies could be explained by observed rates of lightning fire ignition over the modern period of record. We developed a 420-year fire history for the eastern portion of Lac La Croix in the Boundary Waters Canoe Area Wilderness (BWCAW). Seventy-one fire-scarred samples were collected from remnant Pinus resinosa Ait. (red pine) stumps and logs from thirteen distinct island and three mainland forest stands. Collectively these samples contained records of 255 individual fire scars representing 79 fire events from 1636 to 1933 (study area mean fire intervals [MFI] 3.8 yr). Reconstructed fires were spatially and temporally asynchronous and not strongly associated with regional drought (P > 0.05). When compared to the conservative, tree-ring reconstructed estimate of historical fire occurrence and modern lightning-caused fires (1929-2012), a noticeable change in the distribution and frequency of fires within the study area was evident with only two lightning-ignited island fires since 1934 in the study area. Our results suggest a high likelihood that indigenous land use contributed to surface fire ignitions within our study area and highlights the importance of examining the potential effects of past indigenous land use when determining modern approaches to fire and wilderness management in fire-adapted ecosystems.

  18. Long-Term Optical Spectra Variability of BL Lacertae Object S5 ...

    Indian Academy of Sciences (India)

    —methods: periodogram analysis method, wavelet analysis method. 1. Introduction. S5 0716+714 is a typical BL Lac object, and it is very striking due to its observational properties. Heidt & Wagner (1996) found a period of 4 days through flux ...

  19. Effet des conditions climatiques sur le niveau du lac Sidi Ali (Moyen Atlas, Maroc

    Directory of Open Access Journals (Sweden)

    Claude Martin

    2011-11-01

    Full Text Available Le lac Sidi Ali est un lac naturel d'altitude (2070-2080 m, sans exutoire superficiel, déterminé par le barrage d'une coulée basaltique. Doté d'un bassin versant apparent de 15,6 km2, il est alimenté par des eaux de ruissellement et par des sources karstiques. Son niveau subit des variations très fortes, annuelles et interannuelles, sous le contrôle des conditions climatiques, et en particulier des pluies et de l'évapotranspiration. Les périodes de sécheresse qui ont marqué les trois dernières décennies, se sont traduites par un abaissement du niveau de près de 7 m. Mais les précipitations abondantes des années 2008-09 et 2009-10 ont provoqué une nette remontée. Une régression multiple d'assez bonne qualité (r = 0,87 lie la variation annuelle du niveau (d'août à août à différents paramètres (conditions climatiques et niveau initial du lac.Lake Sidi Ali is a natural lake at high altitude (2070-2080 m, without surface outlet, determined by the dam of a basalt flow. With an apparent catchment of 15.6 km2, it is fed by runoff and karst springs. Its level shows strong annual and interannual variations, depending on weather conditions, particularly rainfall and evapotranspiration. Droughts that have marked the last three decades have resulted in a lowering of about 7 m of the water level. But heavy rainfall that occurred in 2008-09 and 2009-10 caused a marked rise. A multiple regression of sufficient quality (r = 0.87 binds the annual change (from august to august at differents parameters (weather conditions and initial level of the lake.

  20. A set of lacZ mutations in Escherichia coli that allow rapid detection of each of the six base substitutions

    International Nuclear Information System (INIS)

    Cupples, C.G.; Miller, J.H.

    1989-01-01

    We describe the construction of six strains of Escherichia coli with different mutations at the same coding position in the lacZ gene, which specifies the active site glutamic acid residue at position 461 in beta'-galactosidase. Each strain is Lac- and reverts to Lac+ only by restoring the glutamic acid codon. The strains have been designed so that each reverts via one of the six base substitutions. The set of strains allows detection of each transition and transversion simply by monitoring the Lac- to Lac+ frequency, as demonstrated here with characterized mutagens and mutator alleles. These strains are useful for rapidly determining the mutagenic specificity of mutagens at a single site, for detecting low levels of stimulation of certain base substitutions, for monitoring specific base changes in response to various experimental conditions or strain backgrounds, and for isolating new mutator strains

  1. Isolation and characterization of Tn917lac-generated competence mutants of Bacillus subtilis

    International Nuclear Information System (INIS)

    Hahn, J.; Albano, M.; Dubnau, D.

    1987-01-01

    The authors isolated 28 mutants of Bacillus subtilis deficient in the development of competence by using the transposon Tn917lacZ as a mutagen. The mutant strains were poorly transformable with plasmid and chromosomal DNAs but were normally transducible and exhibited wild-type resistance to DNA-damaging agents. The mutations were genetically mapped, and the mutants were characterized with respect to their abilities to bind and take up radiolabeled DNA. All were defective in uptake, and some failed to bind significantly amounts of DNA. The abilities of the mutant strains to resolve into two buoyant density classes on Renografin gradients were studied. Most resolved normally, but several banded in Renografin only at the buoyant density of noncompetent cells. The genetic mapping studies and the other analyses suggested that the mutations define a minimum of seven distinct com genes

  2. Geology and age of the Lac a la Perdrix fenite, southern Gatineau district, Quebec

    International Nuclear Information System (INIS)

    Hogarth, D.D.

    1996-01-01

    The Lac a Ia Perdrix fenite lies in the Central Metasedimentary Belt of the Grenville Province. This 30 m wide fenite, adjacent to a narrow calciocarbonatite sill, replaces diopside-oligoclase gneiss and is composed of magnesio-arfvedsonite, aegirine, microcline, albite, and fluorapatite. Near the contact with carbonatite, it contains appreciable monazite and barite whereas aegirine virtually disappears. Fenitization probably took place early in the igneous stage of carbonatite development. A Pb/U monazite age of 1026 ± 2 Ma is thought to date fenite formation. Together with published data, this age shows that carbonatite intruded metamorphic rocks near the close of the Grenville Orogeny. (author). 33 refs., 4 tabs., 5 figs

  3. Gene fusions with lacZ by duplication insertion in the radioresistant bacterium Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Lennon, E.; Minton, K.W.

    1990-01-01

    Deinococcus radiodurans is the most-studied species of a eubacterial family characterized by extreme resistance to DNA damage. We have focused on developing molecular biological techniques to investigate the genetics of this organism. We report construction of lacZ gene fusions by a method involving both in vitro splicing and the natural transformation of D. radiodurans. Numerous fusion strains were identified by expression of beta-galactosidase. Among these fusion strains, several were inducible by exposure to the DNA-damaging agent mitomycin C, and four of the inducible fusion constructs were cloned in Escherichia coli. Hybridization studies indicate that one of the damage-inducible genes contains a sequence reiterated throughout the D. radiodurans chromosome. Survival measurements show that two of the fusion strains have increased sensitivity to mitomycin C, suggesting that the fusions within these strains inactivate repair functions

  4. p21-LacZ reporter mice reflect p53-dependent toxic insult

    International Nuclear Information System (INIS)

    Vasey, Douglas B.; Wolf, C. Roland; MacArtney, Thomas; Brown, Ken; Whitelaw, C. Bruce A.

    2008-01-01

    There is an urgent need to discover less toxic and more selective drugs to treat disease. The use of transgenic mice that report on toxic insult-induced transcription can provide a valuable tool in this regard. To exemplify this strategy, we have generated transgenic mice carrying a p21-LacZ transgene. Transgene activity reflected endogenous p21 gene activation in various tissues, displayed compound-specific spatial expression signatures in the brain and immune tissues and enabled p53-dependent and p53-independent responses to be identified. We discuss the application of these mice in delineating the molecular events in normal cellular growth and disease and for the evaluation of drug toxicity

  5. Données préliminaires sur la diversité du zooplancton du lac Nokoué

    African Journals Online (AJOL)

    SARAH

    31 juil. 2017 ... contribuera davantage à la compréhension de la dynamique de cette communauté biologique du lac. Mots clés ... dans une perspective de gestion durable de la .... ramenés au Laboratoire de Contrôle de Qualité des Eaux.

  6. 78 FR 3911 - Big Stone National Wildlife Refuge, Big Stone and Lac Qui Parle Counties, MN; Final Comprehensive...

    Science.gov (United States)

    2013-01-17

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R3-R-2012-N259; FXRS1265030000-134-FF03R06000] Big Stone National Wildlife Refuge, Big Stone and Lac Qui Parle Counties, MN; Final Comprehensive... significant impact (FONSI) for the environmental assessment (EA) for Big Stone National Wildlife Refuge...

  7. Discovery of Intermediates of lacZ β-Galactosidase Catalyzed Hydrolysis Using dDNP NMR

    DEFF Research Database (Denmark)

    Kjeldsen, Christian; Ardenkjær-Larsen, Jan Henrik; Duus, Jens Ø.

    2018-01-01

    Using dissolution dynamic nuclear polarization, the sensitivity of single scan solution state 13C NMR can be improved up to 4 orders of magnitude. In this study, the enzyme lacZ β-galactosidase from Escherichia coli was subjected to hyperpolarized substrate, and previously unknown reaction...

  8. Discovery of Intermediates of lacZ beta-Galactosidase Catalyzed Hydrolysis Using dDNP NMR

    DEFF Research Database (Denmark)

    Kjeldsen, Christian; Ardenkjær-Larsen, Jan Henrik; Duus, Jens Øllgaard

    2018-01-01

    Using dissolution dynamic nuclear polarization, the sensitivity of single scan solution state C-13 NMR can be improved up to 4 orders of magnitude. In this study, the enzyme lacZ beta-galactosidase from Escherichia coli was subjected to hyperpolarized substrate, and previously unknown reaction...

  9. Bird communities of contrasting semi-natural habitats of Lac bay, Bonaire, during the fall migration season, 2011

    NARCIS (Netherlands)

    Debrot, A.O.; Bemmelen, van R.S.A.; Ligon, J.

    2013-01-01

    The mangrove and seagrass lagoon of Lac Bay on Bonaire covers an area of roughly 700 ha. It is home to endangered green sea turtles, Chelonia mydas, and the Caribbean queen conch, Strombus gigas, and is a roosting and breeding area for several birds. Based on its nature values this 7 km2 bay has

  10. Interplay of protein and DNA structure revealed in simulations of the lac operon.

    Directory of Open Access Journals (Sweden)

    Luke Czapla

    Full Text Available The E. coli Lac repressor is the classic textbook example of a protein that attaches to widely spaced sites along a genome and forces the intervening DNA into a loop. The short loops implicated in the regulation of the lac operon suggest the involvement of factors other than DNA and repressor in gene control. The molecular simulations presented here examine two likely structural contributions to the in-vivo looping of bacterial DNA: the distortions of the double helix introduced upon association of the highly abundant, nonspecific nucleoid protein HU and the large-scale deformations of the repressor detected in low-resolution experiments. The computations take account of the three-dimensional arrangements of nucleotides and amino acids found in crystal structures of DNA with the two proteins, the natural rest state and deformational properties of protein-free DNA, and the constraints on looping imposed by the conformation of the repressor and the orientation of bound DNA. The predicted looping propensities capture the complex, chain-length-dependent variation in repression efficacy extracted from gene expression studies and in vitro experiments and reveal unexpected chain-length-dependent variations in the uptake of HU, the deformation of repressor, and the folding of DNA. Both the opening of repressor and the presence of HU, at levels approximating those found in vivo, enhance the probability of loop formation. HU affects the global organization of the repressor and the opening of repressor influences the levels of HU binding to DNA. The length of the loop determines whether the DNA adopts antiparallel or parallel orientations on the repressor, whether the repressor is opened or closed, and how many HU molecules bind to the loop. The collective behavior of proteins and DNA is greater than the sum of the parts and hints of ways in which multiple proteins may coordinate the packaging and processing of genetic information.

  11. Interplay of protein and DNA structure revealed in simulations of the lac operon.

    Science.gov (United States)

    Czapla, Luke; Grosner, Michael A; Swigon, David; Olson, Wilma K

    2013-01-01

    The E. coli Lac repressor is the classic textbook example of a protein that attaches to widely spaced sites along a genome and forces the intervening DNA into a loop. The short loops implicated in the regulation of the lac operon suggest the involvement of factors other than DNA and repressor in gene control. The molecular simulations presented here examine two likely structural contributions to the in-vivo looping of bacterial DNA: the distortions of the double helix introduced upon association of the highly abundant, nonspecific nucleoid protein HU and the large-scale deformations of the repressor detected in low-resolution experiments. The computations take account of the three-dimensional arrangements of nucleotides and amino acids found in crystal structures of DNA with the two proteins, the natural rest state and deformational properties of protein-free DNA, and the constraints on looping imposed by the conformation of the repressor and the orientation of bound DNA. The predicted looping propensities capture the complex, chain-length-dependent variation in repression efficacy extracted from gene expression studies and in vitro experiments and reveal unexpected chain-length-dependent variations in the uptake of HU, the deformation of repressor, and the folding of DNA. Both the opening of repressor and the presence of HU, at levels approximating those found in vivo, enhance the probability of loop formation. HU affects the global organization of the repressor and the opening of repressor influences the levels of HU binding to DNA. The length of the loop determines whether the DNA adopts antiparallel or parallel orientations on the repressor, whether the repressor is opened or closed, and how many HU molecules bind to the loop. The collective behavior of proteins and DNA is greater than the sum of the parts and hints of ways in which multiple proteins may coordinate the packaging and processing of genetic information.

  12. New Light Curves and Analysis of the Overcontact Binaries PP Lac and DK Sge

    Science.gov (United States)

    Sanders, S. J.; Hargis, J. R.; Bradstreet, D. H.

    2004-12-01

    As a by-product of the ongoing work with the Catalog and AtLas of Eclipsing Binaries database (CALEB; Bradstreet et al. 2004), several hundred eclipsing binary systems have been identified that have either unpublished or poor quality light curves. We present new V & Rc light curves for the overcontact systems PP Lac and DK Sge, both chosen because their deep eclipses (peak-to-peak amplitudes of nearly 0.7 mag) help constrain the light curve modelling. Data were obtained using the 41-cm telescope at the Eastern University Observatory equipped with an SBIG ST-10XME CCD. PP Lac (P= 0.40116 d) is a W-type contact binary with only one previously published light curve (Dumont & Maraziti 1990), but the data are sparse and almost non-existent at primary eclipse. Modelling of these data gave varying results; the published mass ratios differ by nearly 0.3. Our data confirms the noted differing eclipse depths but we find the primary eclipse to be total. We present a new light curve solution using Binary Maker 3 (Bradstreet & Steelman 2002) and Wilson-Devinney, finding the mass ratio to be well-constrained by the duration of total eclipse. A period study will be presented using previously existing and newly derived times of minimum light. DK Sge (P=0.62182 d) appears to be an A-type contact binary with no published light curve. The eclipses are partial, with the primary eclipse being deeper by about 0.08 mag. The maxima show evidence of a slight asymmetry, although the light curve appears to be repeatable over the 1 month of observations. We present the first light curve solution using Binary Maker 3 and Wilson-Devinney, but have limited mass ratio constraints due to the absence of radial velocity data. A period study will be presented using previously existing and newly derived times of minimum light.

  13. Optical polarization of high-energy BL Lacertae objects

    Science.gov (United States)

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

    2016-12-01

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

  14. 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

  15. Multi-epoch intranight optical monitoring of eight radio-quiet BL Lac candidates

    Science.gov (United States)

    Kumar, P.; Gopal-Krishna; Stalin, C. S.; Chand, H.; Srianand, R.; Petitjean, P.

    2017-10-01

    For a new sample of eight weak-line quasars (WLQs) we report a sensitive search in 20 intranight monitoring sessions, for blazar-like optical flux variations on hour-like and longer time-scale (day/month/year-like). The sample consists exclusively of the WLQs that are not radio-loud and either have been classified as 'radio-weak probable BL Lac candidates' and/or are known to have exhibited at least one episode of large, blazar-like optical variability. Whereas only a hint of intranight variability is seen for two of these WLQs, J104833.5+620305.0 (z = 0.219) and J133219.6+622715.9 (z = 3.15), statistically significant internight variability at a few per cent level is detected for three of the sources, including the radio-intermediate WLQ J133219.6+622715.9 (z = 3.15) and the well-known bona fide radio-quiet WLQs J121221.5+534128.0 (z = 3.10) and WLQ J153259.9-003944.1 (z = 4.62). In the rest frame, this variability is intraday and in the far-ultraviolet band. On the time-scale of a decade, we find for three of the WLQs large brightness changes, amounting to 1.655 ± 0.009, 0.163 ± 0.010 and 0.144 ± 0.018 mag, for J104833.5+620305.0, J123743.1+630144.9 and J232428.4+144324.4, respectively. Whereas the latter two are confirmed radio-quiet WLQs, the extragalactic nature of J104833.5+620305.0 remains to be well established, thanks to the absence of any feature(s) in its available optical spectra. This study forms a part of our ongoing campaign of intranight optical monitoring of radio-quiet WLQs, in order to improve the understanding of this enigmatic class of active galactic nuclei and to look among them for a possible tiny, elusive population of radio-quiet BL Lacs.

  16. Blood Glukose Response of Giant Gouramy (Osphronemus gaouramy, Lac. to the Stress of Environmental Temperature Changes

    Directory of Open Access Journals (Sweden)

    S. Hastuti

    2007-08-01

    Full Text Available This experiment was conducted to investigate blood glucose performance of giant gouramy (Osphronemus gouramy, Lac. to environmental changes. Fish with body weight of about 52,15 g was used in the experiment. A hundred and twenty fish were subjected to stress by moving them to another aquarium containing cooler water for 5 minute before put them back to the origin aquarium. The stress treatments were Δ 0°C (A, Δ-3°C (B, Δ-6°C(C, and Δ-9°C(D. Blood glucose was measured at 0, 1, 2, 3, 4 and 5 hours post stress, each for 5 fish. During stress treatment, the survival offish were recorded. To study the role of insulin activation on reducing the stress effects, thirty fish were injected with insulin 2 IU/100 g body weight before subjected them to stressar. Blood glucose level of fish subjected to temperature stress of Δ-9°C was the greatest. The blood glucose response to temperature changes was linear, Y = 4,4543 X + 35,553 with R2 = 0,09976. The survival rate of fish was 100% for all treatments. Injected of insulin 2 IU/100 g body weight was able to reduce hyperglycemia that caused by stress. Key words: Blood glucose, giant gouramy, Osphronemus gouramy, stress   ABSTRAK Penelitian ini dilakukan dengan tujuan untuk mengetahui performa glukosa darah ikan gurami (Osphronemus gouramy, Lac. dalam merespon perubahan suhu lingkungan. Ikan berbobot rata-rata 52,15 g sebanyak 120 ekor diberi stres dengan cara diangkat dan dipindahkan ke suatu wadah yang bersuhu lebih dingin selama 5 menit dan dikembalikan lagi ke wadah mula-mula. Perlakuan stres perubahan suhu dingin tersebut adalah A (Δ 0°C, B (Δ- 3°C, C (Δ-6°C dan D (Δ-9°C. Glukosa darah diukur dari 5 ekor ikan pada jam ke 0, 1, 2, 3, 4 dan 5 jam pascastres. Kelangsungan hidup dihitung pada saat perlakuan stres. Untuk melihat peran aktivasi insulin dalam menekan efek stres, ikan sebanyak 30 ekor diinjeksi insulin 2 iu/100 g bobot badan sebelum diberi stres. Kadar glukosa darah ikan gurame

  17. Bistable behavior of the lac operon in E. coli when induced with a mixture of lactose and TMG

    Directory of Open Access Journals (Sweden)

    Orlando Díaz-Hernández

    2010-07-01

    Full Text Available In this work we investigate multistability in the lac operon of Escherichia coli when it is induced by a mixture of lactose and the non-metabolizable thiomethyl galactoside (TMG. In accordance with previously published experimental results and computer simulations, our simulations predict that: (1 when the system is induced by TMG, the system shows a discernible bistable behavior while, (2 when the system is induced by lactose, bistability does not disappear but excessively high concentrations of lactose would be required to observe it. Finally, our simulation results predict that when a mixture of lactose and TMG is used, the bistability region in the extracellular glucose concentration vs. extracellular lactose concentration parameter space changes in such a way that the model predictions regarding bistability could be tested experimentally. These experiments could help to solve a recent controversy regarding the existence of bistability in the lac operon under natural conditions.

  18. Bistable behavior of the lac operon in E. coli when induced with a mixture of lactose and TMG.

    Science.gov (United States)

    Díaz-Hernández, Orlando; Santillán, Moisés

    2010-01-01

    In this work we investigate multistability in the lac operon of Escherichia coli when it is induced by a mixture of lactose and the non-metabolizable thiomethyl galactoside (TMG). In accordance with previously published experimental results and computer simulations, our simulations predict that: (1) when the system is induced by TMG, the system shows a discernible bistable behavior while, (2) when the system is induced by lactose, bistability does not disappear but excessively high concentrations of lactose would be required to observe it. Finally, our simulation results predict that when a mixture of lactose and TMG is used, the bistability region in the extracellular glucose concentration vs. extracellular lactose concentration parameter space changes in such a way that the model predictions regarding bistability could be tested experimentally. These experiments could help to solve a recent controversy regarding the existence of bistability in the lac operon under natural conditions.

  19. Elegant objects

    CERN Document Server

    Bugayenko, Yegor

    2017-01-01

    There are 23 practical recommendations for object-oriented programmers. Most of them are completely against everything you've read in other books. For example, static methods, NULL references, getters, setters, and mutable classes are called evil. Compound variable names, validators, private static literals, configurable objects, inheritance, annotations, MVC, dependency injection containers, reflection, ORM and even algorithms are our enemies.

  20. Objective lens

    Science.gov (United States)

    Olczak, Eugene G. (Inventor)

    2011-01-01

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

  1. Karakteristik Enzim Digesti, Protease dan Amilase, Ikan Gurami (Osphronemus gouramy Lac. pada Fase Pertumbuhan

    Directory of Open Access Journals (Sweden)

    Untung Susilo

    2015-05-01

    Full Text Available Suatu penelitian untuk mengetahui karakteristik enzim digesti, protease dan amilase pada ikan gurami, Osphronemus gouramy Lac., telah dilakukan dengan metode survey. Jumlah ikan yang digunakan untuk penelitian sebanyak 25 ekor yang dikelompokan menjadi tiga kelompok ukuran13,29, 35,86 dan 91,86 g/ekor. Hasil penelitian menunjukkan bahwa aktivitas protease digesti ikan gurami berbeda secara signifikan pada segmen usus dan pH buffer yang berbeda (P.05, namun berbeda secara signifikan diantara ukuran ikan yang berbeda (P<.05, dan aktivitas amilase tertinggi dijumpai pada ikan dengan ukuran terkecil. Kesimpulan yang dapat diambil adalah bahwa aktivitas protease dan amilase dijumpai sepanjang saluran digestinya baik pada ikan yang berukuran kecil maupun besar. Aktivitas protease umumnya tinggi pada suasana asam dan netral pada usus depan dan tengah. Aktivitas protease ikan yang berukuran besar lebih rendah dari pada ikan yang berukuran lebih kecil. Aktivitas amilase tidak terdapat perbedaan diantara segmen usus yang diuji, namun aktivitas amilase tertinggi dijumpai pada ikan dengan berat rata-rata 13,29 g/ekor

  2. Burn care in Los Angeles, California: LAC+USC experience 1994-2004.

    Science.gov (United States)

    Garner, Warren L; Reiss, Matthew

    2005-01-01

    The LAC+USC Burn Center has admitted 3118 patients for treatment in the last 10 years. A majority of patients were young adults (1868), with the second largest group being small children (543). The ethnicity of the patients reflects the diverse nature of the population of Los Angeles County. Forty-eight percent of injuries were less than 5% TBSA and approximately 2% were greater than 60% TBSA. Eighty-two percent were accidental injuries. Sixty percent of admitted patients underwent skin grafting. Mortality was negligible in the group with burns over less than 10% of their body and very high (15/19), 79% in the most severely burned group. Further, there was a high correlation between age and mortality. Complications during treatment included: deep venous thrombosis 1% per year; pulmonary emboli in 5 patients; endotracheal tube dislodgment early or self-extubation about 1 month (11.3 per year); 4.5 patients per year who developed acute renal failure; abdominal compartment syndrome developed in 4.7 patients each year; heterotopic ossification was seen in 4 patients (0.4%); 4 patients (0.4%) developed stage II-IV pressure sores; hypothermia was present in 0.8% of patients.

  3. Surface radiant flux densities inferred from LAC and GAC AVHRR data

    Science.gov (United States)

    Berger, F.; Klaes, D.

    To infer surface radiant flux densities from current (NOAA-AVHRR, ERS-1/2 ATSR) and future meteorological (Envisat AATSR, MSG, METOP) satellite data, the complex, modular analysis scheme SESAT (Strahlungs- und Energieflüsse aus Satellitendaten) could be developed (Berger, 2001). This scheme allows the determination of cloud types, optical and microphysical cloud properties as well as surface and TOA radiant flux densities. After testing of SESAT in Central Europe and the Baltic Sea catchment (more than 400scenes U including a detailed validation with various surface measurements) it could be applied to a large number of NOAA-16 AVHRR overpasses covering the globe.For the analysis, two different spatial resolutions U local area coverage (LAC) andwere considered. Therefore, all inferred results, like global area coverage (GAC) U cloud cover, cloud properties and radiant properties, could be intercompared. Specific emphasis could be made to the surface radiant flux densities (all radiative balance compoments), where results for different regions, like Southern America, Southern Africa, Northern America, Europe, and Indonesia, will be presented. Applying SESAT, energy flux densities, like latent and sensible heat flux densities could also be determined additionally. A statistical analysis of all results including a detailed discussion for the two spatial resolutions will close this study.

  4. Europa-Latinoamérica: amigos complicados. Sobre la IV EU-LAC en Viena, Austria

    Directory of Open Access Journals (Sweden)

    Gerhard Drekonja-Kornat

    2014-06-01

    Full Text Available Para los presidentes latinoamericanos, las cumbres ya son rutina. Para Viena, la anfitriona de la IV reunión EU-LAC que se realizó del 11 al 13 de mayo de 2006, esta cumbre fue el acontecimiento del siglo. Se podría decir que fue la continuación del Congreso de Viena de 1815. Adecuadamente acicalada, se presentó la capital austriaca, a la cual después de Río, Madrid y Guadalajara, le tocó organizar la cuarta Cumbre de Jefes de Estado y de Gobierno de la Unión Europea, América Latina y el Caribe. Puesto que también se encontraban presentes los representantes de los países adherentes y candidatos a ingresar a la Unión –incluso el primer ministro de Turquía, R. T. Erdogan estuvo presente–, se tomó la tradicional “foto familiar” con 60 participantes.

  5. ANTI-CORRELATED OPTICAL FLUX AND POLARIZATION VARIABILITY IN BL LAC

    Energy Technology Data Exchange (ETDEWEB)

    Gaur, Haritma [Inter-University Centre for Astronomy and Astrophysics (IUCAA), Ganeshkhind, Pune 411 007 (India); Gupta, Alok C. [Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital 263 129 (India); Wiita, Paul J. [Department of Physics, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628-0718 (United States); Uemura, Makoto; Itoh, Ryosuke; Sasada, Mahito, E-mail: haritma@iucaa.ernet.in [Hiroshima Astrophysical Science Center, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan)

    2014-01-20

    We present the results of photometric (V band) and polarimetric observations of the blazar BL Lac during 2008-2010 using TRISPEC attached to the KANATA 1.5 m telescope in Japan. The data reveal a great deal of variability ranging from days to months with detection of strong variations in fractional polarization. The V band flux strongly anticorrelates with the degree of polarization during the first of two observing seasons but not during the second. The direction of the electric vector, however, remained roughly constant during all of our observations. These results are consistent with a model with at least two emission regions being present, with the more variable component having a polarization direction nearly perpendicular to that of the relatively quiescent region so that a rising flux can produce a decline in degree of polarization. We also computed models involving helical jet structures and single transverse shocks in jets and show that they might also be able to agree with the anticorrelations between flux and fractional polarization.

  6. DNA adducts, mutant frequencies and mutation spectra in λlacZ transgenic mice treated with N-nitrosodimethylamine

    NARCIS (Netherlands)

    Souliotis, V.L.; Delft, J.H.M. van; Steenwinkel, M.-J.S.T.; Baan, R.A.; Kyrtopoulos, S.A.

    1998-01-01

    Groups of λlacZ transgenic mice were treated i.p. with N-nitrosodimethylamine (NDMA) as single doses of 5 mg/kg or 10 mg/kg or as 10 daily doses of 1 mg/kg and changes in DNA N7- or O6-methylguanine or the repair enzyme O6-alkylguanine-DNA alkyltransferase (AGT) were followed for up to 14 days in

  7. Largemouth bass (Micropterus salmoides Lacépède): reproduction management and larval rearing in Italy

    OpenAIRE

    A. Dees; P. Melotti; R. Vicenzi; A. Roncarati

    2010-01-01

    Micropterus salmoides (Lacépède) was originally present into the waters of the eastern United States of America, northern Mexico and southern Canada. This species can be distinguished from the other black basses by the fact that its mouth extends to and beyond the edge of the eye and the first and the second dorsal fins are almost separated by a deep dip and there are no scales on the soft rayed of the second dorsal fin.

  8. Largemouth bass (Micropterus salmoides Lacépède: reproduction management and larval rearing in Italy

    Directory of Open Access Journals (Sweden)

    A. Dees

    2010-01-01

    Full Text Available Micropterus salmoides (Lacépède was originally present into the waters of the eastern United States of America, northern Mexico and southern Canada. This species can be distinguished from the other black basses by the fact that its mouth extends to and beyond the edge of the eye and the first and the second dorsal fins are almost separated by a deep dip and there are no scales on the soft rayed of the second dorsal fin.

  9. Optimization of lignin peroxidase, manganese peroxidase, and Lac production from Ganoderma lucidum under solid state fermentation of pineapple leaf

    OpenAIRE

    Sudha Hariharan; Padma Nambisan

    2013-01-01

    This study was undertaken to isolate ligninase-producing white-rot fungi for use in the extraction of fibre from pineapple leaf agriwaste. Fifteen fungal strains were isolated from dead tree trunks and leaf litter. Ligninolytic enzymes (lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac)), were produced by solid-state fermentation (SSF) using pineapple leaves as the substrate. Of the isolated strains, the one showing maximum production of ligninolytic enzymes was identified...

  10. The extent of co-metabolism of glucose and galactose by L. lactis changes with the expression of the lacSZ operon from Streptococcus thermophilus

    DEFF Research Database (Denmark)

    Solem, Christian; Købmann, Brian Jensen; Jensen, Peter Ruhdal

    2008-01-01

    The lactose transporter and β-galactosidase from Streptococcus thermophilus, encoded by the lacSZ operon, were introduced into the lactose-negative strain Lactococcus lactis MG1363 and the expression of the lacSZ operon was modulated by substitution of the native promoter with randomized synthetic...... promoters. A series of strains with various expression levels of lacSZ were examined for their fermentation of lactose. Strains with a high expression level were found to metabolize lactose in a similar manner to S. thermophilus, i.e. the galactose moiety of lactose was excreted to the growth medium...... and only glucose was metabolized in glycolysis. Interestingly, strains with low expression of the operon showed a mixed acid metabolism and co-metabolism of galactose and glucose. The lactose flux increased gradually with increasing expression of the lacSZ operon until an optimum was observed...

  11. Mutagenicity of ultraviolet A radiation in the lacI transgene in Big Blue mouse embryonic fibroblasts

    International Nuclear Information System (INIS)

    Kim, Sang-in; Pfeifer, Gerd P.; Besaratinia, Ahmad

    2007-01-01

    Sunlight ultraviolet A (UVA) irradiation has been implicated in the etiology of human skin cancer. A genotoxic mode of action for UVA radiation has been suggested that involves photosensitization reactions giving rise to promutagenic DNA lesions. We investigated the mutagenicity of UVA in the lacI transgene in Big Blue mouse embryonic fibroblasts. UVA irradiation of these cells at a physiologically relevant dose of 18 J/cm 2 caused a 2.8-fold increase in the lacI mutant frequency relative to control, i.e., 12.12 ± 1.84 versus 4.39 ± 1.99 x 10 -5 (mean ± S.D.). DNA sequencing analysis showed that of 100 UVA-induced mutant plaques and 54 spontaneously arisen control plaques, 97 and 51, respectively, contained a minimum of one mutation along the lacI transgene. The vast majority of both induced- and spontaneous mutations were single base substitutions, although less frequently, there were also single and multiple base deletions and insertions, and tandem base substitutions. Detailed mutation spectrometry analysis revealed that G:C → T:A transversions, the signature mutations of oxidative DNA damage, were significantly induced by UVA irradiation (P -5 ; P < 0.00001). These findings are in complete agreement with those previously observed in the cII transgene of the same model system, and reaffirm the notion that intracellular photosensitization reactions causing promutagenic oxidative DNA damage are involved in UVA genotoxicity

  12. Study feature of variability extragalactic radio sources 3C 446 and BL Lac in the centimeter wavelength range

    International Nuclear Information System (INIS)

    Sukharev, A.L.

    2015-01-01

    This work presents the results of the analysis of long-term monitoring (over 40 years) changes in radio fluxes of the two extragalactic sources - 3C 446, and BL Lac. Observations at frequencies of 14.5, 8, 4.8 GHz were obtained in the Michigan Radio Astronomy Observatory (UMRAO). With using Fourier filtering were selected 0- C (short-period), and the trend component of flux variations that were analyzed separately with using the wavelet-analysis method. Each of these components is associated with certain physical processes in the 'core-accretion disk-jet' system. Were constructed time-frequency wavelet-spectra showing the changes of the frequency composition of the investigated data over time. For the trend component values of the main periods of -4-9 years (3C 446) and -8 years (BL Lac), for 0- C component -0.8-3 years (3C 446) and -0.6-4 years (BL Lac) and they appear in the temporal and structural changes of the jet. On the basis of calculating the global wavelet-spectra in the frequency range identified main phases activity of radio sources. Obtained comparison between the dynamics of jets (Mojave VLBI images), and change the frequency spectral structure of the studied data. With bandpass wavelet filtering, flux components corresponding to the main periods in the spectra, were identified and also found the delay between the observation frequencies in spectral bands of these periods

  13. Extended objects

    International Nuclear Information System (INIS)

    Creutz, M.

    1976-01-01

    After some disconnected comments on the MIT bag and string models for extended hadrons, I review current understanding of extended objects in classical conventional relativistic field theories and their quantum mechanical interpretation

  14. Complete genome sequence of hypervirulent and outbreak-associated Acinetobacter baumannii strain LAC-4: epidemiology, resistance genetic determinants and potential virulence factors

    Science.gov (United States)

    Ou, Hong-Yu; Kuang, Shan N.; He, Xinyi; Molgora, Brenda M.; Ewing, Peter J.; Deng, Zixin; Osby, Melanie; Chen, Wangxue; Xu, H. Howard

    2015-01-01

    Acinetobacter baumannii is an important human pathogen due to its multi-drug resistance. In this study, the genome of an ST10 outbreak A. baumannii isolate LAC-4 was completely sequenced to better understand its epidemiology, antibiotic resistance genetic determinants and potential virulence factors. Compared with 20 other complete genomes of A. baumannii, LAC-4 genome harbors at least 12 copies of five distinct insertion sequences. It contains 12 and 14 copies of two novel IS elements, ISAba25 and ISAba26, respectively. Additionally, three novel composite transposons were identified: Tn6250, Tn6251 and Tn6252, two of which contain resistance genes. The antibiotic resistance genetic determinants on the LAC-4 genome correlate well with observed antimicrobial susceptibility patterns. Moreover, twelve genomic islands (GI) were identified in LAC-4 genome. Among them, the 33.4-kb GI12 contains a large number of genes which constitute the K (capsule) locus. LAC-4 harbors several unique putative virulence factor loci. Furthermore, LAC-4 and all 19 other outbreak isolates were found to harbor a heme oxygenase gene (hemO)-containing gene cluster. The sequencing of the first complete genome of an ST10 A. baumannii clinical strain should accelerate our understanding of the epidemiology, mechanisms of resistance and virulence of A. baumannii. PMID:25728466

  15. Effect of the partial NaCl substitution by other chloride salts on the volatile profile during the ripening of dry-cured lacón

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, R.; Munekata, P.E.; Cittadini, A.; Lorenzo, J.M.

    2016-07-01

    The influence of three salting treatments (treatment II: 50% NaCl-50% KCl; III: 45% NaCl-25% KCl-20% CaCl2-10% MgCl2; IV: 30% NaCl-50% KCl-15% CaCl2-5% MgCl2) on the formation of volatile compounds throughout the process was studied and compared to those of a control “lacón” (treatment I: 100% NaCl). There was an intense formation of volatile compounds throughout the processing, particularly during the dry-ripening stage. The most abundant chemical family in all the formulations, in the final product was hydrocarbons followed by aldehydes. The total volatile compound release was more intense in the control “lacóns” (1164 AU×106 ·g–1dry matter) than in “lacóns” from formulations II, III and IV (817–891 AU×106 ·g−1dry matter). The “lacóns” from formulation I showed the highest amounts of aldehydes. The “lacóns” from formulations I and II presented the highest amounts of hydrocarbons. The main conclusion is that the replacement of NaCl produces changes in the volatile profile and could be affect the aroma of “lacón”. (Author)

  16. Trusted Objects

    International Nuclear Information System (INIS)

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

    1999-01-01

    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.''

  17. Merging a Terrain-Based Parameter and Snow Particle Counter Data for the Assessment of Snow Redistribution in the Col du Lac Blanc Area

    Science.gov (United States)

    Schön, Peter; Prokop, Alexander; Naaim-Bouvet, Florence; Vionnet, Vincent; Guyomarc'h, Gilbert; Heiser, Micha; Nishimura, Kouichi

    2015-04-01

    Wind and the associated snow drift are dominating factors determining the snow distribution and accumulation in alpine areas, resulting in a high spatial variability of snow depth that is difficult to evaluate and quantify. The terrain-based parameter Sx characterizes the degree of shelter or exposure of a grid point provided by the upwind terrain, without the computational complexity of numerical wind field models. The parameter has shown to qualitatively predict snow redistribution with good reproduction of spatial patterns. It does not, however, provide a quantitative estimate of changes in snow depths. The objective of our research was to introduce a new parameter to quantify changes in snow depths in our research area, the Col du Lac Blanc in the French Alps. The area is at an elevation of 2700 m and particularly suited for our study due to its consistently bi-modal wind directions. Our work focused on two pronounced, approximately 10 m high terrain breaks, and we worked with 1 m resolution digital snow surface models (DSM). The DSM and measured changes in snow depths were obtained with high-accuracy terrestrial laser scan (TLS) measurements. First we calculated the terrain-based parameter Sx on a digital snow surface model and correlated Sx with measured changes in snow-depths (Δ SH). Results showed that Δ SH can be approximated by Δ SHestimated = α * Sx, where α is a newly introduced parameter. The parameter α has shown to be linked to the amount of snow deposited influenced by blowing snow flux. At the Col du Lac Blanc test side, blowing snow flux is recorded with snow particle counters (SPC). Snow flux is the number of drifting snow particles per time and area. Hence, the SPC provide data about the duration and intensity of drifting snow events, two important factors not accounted for by the terrain parameter Sx. We analyse how the SPC snow flux data can be used to estimate the magnitude of the new variable parameter α . To simulate the development

  18. Improving the Terrain-Based Parameter for the Assessment of Snow Redistribution in the Col du Lac Blanc Area and Comparisons with TLS Snow Depth Data

    Science.gov (United States)

    Schön, Peter; Prokop, Alexander; Naaim-Bouvet, Florence; Nishimura, Kouichi; Vionnet, Vincent; Guyomarc'h, Gilbert

    2014-05-01

    Wind and the associated snow drift are dominating factors determining the snow distribution and accumulation in alpine areas, resulting in a high spatial variability of snow depth that is difficult to evaluate and quantify. The terrain-based parameter Sx characterizes the degree of shelter or exposure of a grid point provided by the upwind terrain, without the computational complexity of numerical wind field models. The parameter has shown to qualitatively predict snow redistribution with good reproduction of spatial patterns, but has failed to quantitatively describe the snow redistribution, and correlations with measured snow heights were poor. The objective of our research was to a) identify the sources of poor correlations between predicted and measured snow re-distribution and b) improve the parameters ability to qualitatively and quantitatively describe snow redistribution in our research area, the Col du Lac Blanc in the French Alps. The area is at an elevation of 2700 m and particularly suited for our study due to its constant wind direction and the availability of data from a meteorological station. Our work focused on areas with terrain edges of approximately 10 m height, and we worked with 1-2 m resolution digital terrain and snow surface data. We first compared the results of the terrain-based parameter calculations to measured snow-depths, obtained by high-accuracy terrestrial laser scan measurements. The results were similar to previous studies: The parameter was able to reproduce observed patterns in snow distribution, but regression analyses showed poor correlations between terrain-based parameter and measured snow-depths. We demonstrate how the correlations between measured and calculated snow heights improve if the parameter is calculated based on a snow surface model instead of a digital terrain model. We show how changing the parameter's search distance and how raster re-sampling and raster smoothing improve the results. To improve the parameter

  19. Mechanism of salt-induced activity enhancement of a marine-derived laccase, Lac15.

    Science.gov (United States)

    Li, Jie; Xie, Yanan; Wang, Rui; Fang, Zemin; Fang, Wei; Zhang, Xuecheng; Xiao, Yazhong

    2018-04-01

    Laccase (benzenediol: oxygen oxidoreductases, EC1.10.3.2) is a multi-copper oxidase capable of oxidizing a variety of phenolic and other aromatic organic compounds. The catalytic power of laccase makes it an attractive candidate for potential applications in many areas of industry including biodegradation of organic pollutants and synthesis of novel drugs. Most laccases are vulnerable to high salt and have limited applications. However, some laccases are not only tolerant to but also activated by certain concentrations of salt and thus have great application potential. The mechanisms of salt-induced activity enhancement of laccases are unclear as yet. In this study, we used dynamic light scattering, size exclusion chromatography, analytical ultracentrifugation, intrinsic fluorescence emission, circular dichroism, ultraviolet-visible light absorption, and an enzymatic assay to investigate the potential correlation between the structure and activity of the marine-derived laccase, Lac15, whose activity is promoted by low concentrations of NaCl. The results showed that low concentrations of NaCl exert little influence on the protein structure, which was partially folded in the absence of the salt; moreover, the partially folded rather than the fully folded state seemed to be favorable for enzyme activity, and this partially folded state was distinctive from the so-called 'molten globule' occasionally observed in active enzymes. More data indicated that salt might promote laccase activity through mechanisms involving perturbation of specific local sites rather than a change in global structure. Potential binding sites for chloride ions and their roles in enzyme activity promotion are proposed.

  20. Attachment to place in advanced age: A study of the LiLACS NZ cohort.

    Science.gov (United States)

    Wiles, Janine L; Rolleston, Anna; Pillai, Avinesh; Broad, Joanna; Teh, Ruth; Gott, Merryn; Kerse, Ngaire

    2017-07-01

    An extensive body of research theorises that attachment to place is positively associated with health, particularly for older people. Building on this, we measure how indicators of attachment to place are associated with health for in people of advanced age in New Zealand. We use data from a cohort study (LiLACS NZ), which includes an indigenous Māori cohort aged 80-90 years and a non-Māori cohort aged 85 years from a mixed urban/rural region in New Zealand. Each cohort undertook a comprehensive interview and health assessment (n = 267 Māori and n = 404 non-Māori). Using multivariate regression analyses, we explore participants' feelings for and connectedness with their home, community and neighbourhood; nature and the outdoors; expectations about and enthusiasm for residential mobility; and how all these are associated with measures of health (e.g., SF-12 physical and mental health related quality of life) and functional status (e.g., NEADL). We demonstrate that people in advanced age hold strong feelings of attachment to place. We also establish some positive associations between attachment to place and health in advanced age, and show how these differ for the indigenous and non-indigenous cohorts. For older Māori there were strong associations between various health measures and the importance of nature and the outdoors, and connectedness to neighbourhood and community. For older non-Māori, there were strong associations between health and liking home and neighbourhood, and feeling connected to their community and neighbourhood. Place attachment, and particularly its relationship to health, operates in different ways for different groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. End of life care preferences among people of advanced age: LiLACS NZ.

    Science.gov (United States)

    Gott, Merryn; Frey, Rosemary; Wiles, Janine; Rolleston, Anna; Teh, Ruth; Moeke-Maxwell, Tess; Kerse, Ngaire

    2017-12-19

    Understanding end of life preferences amongst the oldest old is crucial to informing appropriate palliative and end of life care internationally. However, little has been reported in the academic literature about the end of life preferences of people in advanced age, particularly the preferences of indigenous older people, including New Zealand Māori. Data on end of life preferences were gathered from 147 Māori (aged >80 years) and 291 non- Māori aged (>85 years), during three waves of Te Puawaitangi O Nga Tapuwae Kia Ora Tonu, Life and Living in Advanced Age (LiLACs NZ). An interviewer-led questionnaire using standardised tools and including Māori specific subsections was used. The top priority for both Māori and non-Māori participants at end of life was 'not being a burden to my family'. Interestingly, a home death was not a high priority for either group. End of life preferences differed by gender, however these differences were culturally contingent. More female Māori participants wanted spiritual practices at end of life than male Māori participants. More male non-Māori participants wanted to be resuscitated than female non- Māori participants. That a home death was not in the top three end of life priorities for our participants is not consistent with palliative care policy in most developed countries where place of death, and particularly home death, is a central concern. Conversely our participants' top concern - namely not being a burden - has received little research or policy attention. Our results also indicate a need to pay attention to diversity in end of life preferences amongst people of advanced age, as well as the socio-cultural context within which preferences are formulated.

  2. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France.

    Science.gov (United States)

    Certad, Gabriela; Dupouy-Camet, Jean; Gantois, Nausicaa; Hammouma-Ghelboun, Ourida; Pottier, Muriel; Guyot, Karine; Benamrouz, Sadia; Osman, Marwan; Delaire, Baptiste; Creusy, Colette; Viscogliosi, Eric; Dei-Cas, Eduardo; Aliouat-Denis, Cecile Marie; Follet, Jérôme

    2015-01-01

    Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the

  3. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman in France.

    Directory of Open Access Journals (Sweden)

    Gabriela Certad

    Full Text Available Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman in France, 41 entire fish and 100 fillets (cuts of fish flesh were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%, distributed as follows: 13 (87% C. parvum, 1 (7% C. molnari, and 1 (7% mixed infection (C. parvum and C. molnari. C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60 was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by

  4. Dating fractures and fracture movement in the Lac du Bonnet Batholith

    International Nuclear Information System (INIS)

    Gascoyne, M.; Brown, A.; Ejeckam, R.B.; Everitt, R.A.

    1997-04-01

    This report examines and summarizes all work that has been done from 1980 to the present in determining the age of rock crystallization, fracture initiation, fracture reactivation and rates of fracture movement in the Lac du Bonnet Batholith to provide information for Atomic Energy of Canada Limited's (AECL) Canadian Nuclear Fuel Waste Management Program. Geological and petrographical indicators of relative age (e.g. cross-cutting relationships, sequences of fracture infilling minerals, P-T characteristics of primary and secondary minerals) are calibrated with radiometric age determinations on minerals and whole rock samples, using 87 Rb- 87 Sr, 40 K- 39 Ar, 40 Ar- 39 Ar and fission track methods. Most fractures and fracture zones inclined at low angles are found to be ancient features, first formed in the Early Proterozoic under conditions of deuteric alteration. Following some movement on fractures in the Late Proterozoic and Early Paleozoic, reactivation of fractures during the Pleistocene is established from uranium-series dating methods and use of stable isotopic contents of fracture infilling minerals (mainly calcite). Some indication of movement on fracture zones during the Pleistocene is given by electron spin resonance dating techniques on fault gouge. The slow rate of propagation of fractures is indicated by mineral infillings, their P-T characteristics and U-series calcite ages in a fracture in sparsely fractured rock, accessible from AECL's Underground Research Laboratory. These results collectively indicate that deep fractures observed in the batholith are ancient features and the fracturing and jointing in the upper 200 m is relatively recent (< 1 Ma) and largely a result of stress release. (author)

  5. Karyotypic diversity and evolutionary trends in the Neotropical catfish genus Hypostomus Lacépède, 1803 (Teleostei, Siluriformes, Loricariidae

    Directory of Open Access Journals (Sweden)

    Anderson Alves

    2012-12-01

    Full Text Available The family Loricariidae with 813 nominal species is one of the largest fish families of the world. Hypostominae, its more complex subfamily, was recently divided into five tribes. The tribe Hypostomini is composed of a single genus, Hypostomus Lacépède, 1803, which exhibits the largest karyotypic diversity in the family Loricariidae. With the main objective of contributing to a better understanding of the relationship and the patterns of evolution among the karyotypes of Hypostomus species, cytogenetic studies were conducted in six species of the genus from Brazil and Venezuela. The results show a great chromosome variety with diploid numbers ranging from 2n=68 to 2n=76, with a clear predominance of acrocentric chromosomes. The Ag-NORs are located in terminal position in all species analyzed. Three species have single Ag-NORs (Hypostomus albopunctatus (Regan, 1908, H. prope plecostomus (Linnaeus, 1758, and H. prope paulinus (Ihering, 1905 and three have multiple Ag-NORs (H. ancistroides (Ihering, 1911, H. prope iheringi (Regan, 1908, and H. strigaticeps (Regan, 1908. In the process of karyotype evolution of the group, the main type of chromosome rearrangements was possibly centric fissions, which may have been facilitated by the putative tetraploid origin of Hypostomus species. The relationship between the karyotype changes and the evolution in the genus is discussed.

  6. Soft X-Ray Observations of a Complete Sample of X-Ray--selected BL Lacertae Objects

    Science.gov (United States)

    Perlman, Eric S.; Stocke, John T.; Wang, Q. Daniel; Morris, Simon L.

    1996-01-01

    We present the results of ROSAT PSPC observations of the X-ray selected BL Lacertae objects (XBLs) in the complete Einstein Extended Medium Sensitivity Survey (EM MS) sample. None of the objects is resolved in their respective PSPC images, but all are easily detected. All BL Lac objects in this sample are well-fitted by single power laws. Their X-ray spectra exhibit a variety of spectral slopes, with best-fit energy power-law spectral indices between α = 0.5-2.3. The PSPC spectra of this sample are slightly steeper than those typical of flat ratio-spectrum quasars. Because almost all of the individual PSPC spectral indices are equal to or slightly steeper than the overall optical to X-ray spectral indices for these same objects, we infer that BL Lac soft X-ray continua are dominated by steep-spectrum synchrotron radiation from a broad X-ray jet, rather than flat-spectrum inverse Compton radiation linked to the narrower radio/millimeter jet. The softness of the X-ray spectra of these XBLs revives the possibility proposed by Guilbert, Fabian, & McCray (1983) that BL Lac objects are lineless because the circumnuclear gas cannot be heated sufficiently to permit two stable gas phases, the cooler of which would comprise the broad emission-line clouds. Because unified schemes predict that hard self-Compton radiation is beamed only into a small solid angle in BL Lac objects, the steep-spectrum synchrotron tail controls the temperature of the circumnuclear gas at r ≤ 1018 cm and prevents broad-line cloud formation. We use these new ROSAT data to recalculate the X-ray luminosity function and cosmological evolution of the complete EMSS sample by determining accurate K-corrections for the sample and estimating the effects of variability and the possibility of incompleteness in the sample. Our analysis confirms that XBLs are evolving "negatively," opposite in sense to quasars, with Ve/Va = 0.331±0.060. The statistically significant difference between the values for X

  7. Fashion Objects

    DEFF Research Database (Denmark)

    Andersen, Bjørn Schiermer

    2009-01-01

    -- an outline which at the same time indicates the need for transformations of the Durkheimian model on decisive points. Thus, thirdly, it returns to Durkheim and undertakes to develop his concepts in a direction suitable for a sociological theory of fashion. Finally, it discusses the theoretical implications......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...

  8. Utilities objectives

    International Nuclear Information System (INIS)

    Cousin, Y.; Fabian, H.U.

    1996-01-01

    The policy of French and german utilities is to make use of nuclear energy as a long term, competitive and environmentally friendly power supply. The world electricity generation is due to double within the next 30 years. In the next 20 to 30 years the necessity of nuclear energy will be broadly recognized. More than for most industries, to deal properly with nuclear energy requires the combination of a consistent political will, of a proper institutional framework, of strong and legitimate control authorities, of a sophisticated industry and of operators with skilled management and human resources. One of the major risk facing nuclear energy is the loss of competitiveness. This can be achieved only through the combination of an optimized design, a consistent standardization, a proper industrial partnership and a stable long term strategy. Although the existing plants in Western Europe are already very safe, the policy is clearly to enhance the safety of the next generation of nuclear plants which are designing today. The French and German utilities have chosen an evolutionary approach based on experience and proven technologies, with an enhanced defense in depth and an objective of easier operation and maintenance. The cost objective is to maintain and improve what has been achieved in the best existing power plants in both countries. This calls for rational choices and optimized design to meet the safety objectives, a strong standardization policy, short construction times, high availability and enough flexibility to enable optimization of the fuel cycle throughout the lifetime of the plants. The conceptual design phase has proven that the French and German teams from industry and from the utilities are able to pursue both the safety and the cost objectives, basing their decision on a rational approach which could be accepted by the safety authorities. (J.S.)

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

    Science.gov (United States)

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

    2011-01-01

    Context. Observations of the gamma-ray sky with Fermi led to significant advances towards understanding blazars, the most extreme class of Active Galactic Nuclei. A large fraction of the population detected by Fermi is formed by BL Lacertae (BL Lac) objects, whose sample has always suffered from a severe redshift incompleteness due to the quasi-featureless optical spectra. Aims. Our goal is to provide a significant increase of the number of confirmed high-redshift BL Lac objects contained in the 2 LAC Fermi/LAT catalog. Methods. For 103 Fermi/LAT blazars, photometric redshifts using spectral energy distribution fitting have been obtained. The photometry includes 13 broad-band filters from the far ultraviolet to the near-IR observed with Swift/UVOT and the multi-channel imager GROND at the MPG/ESO 2.2m telescope. Data have been taken quasi-simultaneously and the remaining source-intrinsic variability has been corrected for. Results. We release the UV-to-near-IR 13-band photometry for all 103 sources and provide redshift constraints for 75 sources without previously known redshift. Out of those, eight have reliable photometric redshifts at z > or approx. 1.3, while for the other 67 sources we provide upper limits. Six of the former eight are BL Lac objects, which quadruples the sample of confirmed high-redshift BL Lac. This includes three sources with redshifts higher than the previous record for BL Lac, including CRATES J0402-2615, with the best-fit solution at z approx. = 1.9.

  10. Residues in the H+ Translocation Site Define the pKa for Sugar Binding to LacY†

    Science.gov (United States)

    Smirnova, Irina; Kasho, Vladimir; Sugihara, Junichi; Choe, Jun-Yong; Kaback, H. Ronald

    2009-01-01

    A remarkably high pKa of approximately 10.5 has been determined for sugar-binding affinity to the lactose permease of Escherichia coli (LacY), indicating that, under physiological conditions, substrate binds to fully protonated LacY. We have now systematically tested site-directed replacements for the residues involved in sugar binding, as well as H+ translocation and coupling, in order to determine which residues may be responsible for this alkaline pKa. Mutations in the sugar-binding site (Glu126, Trp151, Glu269) markedly decrease affinity for sugar but do not alter the pKa for binding. In contrast, replacements for residues involved in H+ translocation (Arg302, Tyr236, His322, Asp240, Glu325, Lys319) exhibit pKa values for sugar binding that are either shifted toward neutral pH or independent of pH. Values for the apparent dissociation constant for sugar binding (Kdapp) increase greatly for all mutants except neutral replacements for Glu325 or Lys319, which are characterized by remarkably high affinity sugar binding (i.e., low Kdapp) from pH 5.5 to pH 11. The pH dependence of the on- and off-rate constants for sugar binding measured directly by stopped-flow fluorometry implicates koff as a major factor for the affinity change at alkaline pH and confirms the effects of pH on Kdapp inferred from steady-state fluorometry. These results indicate that the high pKa for sugar binding by wild-type LacY cannot be ascribed to any single amino acid residue but appears to reside within a complex of residues involved in H+ translocation. There is structural evidence for water bound in this complex, and the water could be the site of protonation responsible for the pH dependence of sugar binding. PMID:19689129

  11. Déclin et restauration de la population de truites lacustres (Salmo trutta lacustris L. du lac de Constance

    Directory of Open Access Journals (Sweden)

    RUHLÉ C.

    1990-10-01

    Full Text Available Le déclin de la population de truites migratrices du lac de Constance a débuté vers 1950 quand un barrage a été construit sur le Rhin, affluent principal de ce lac, coupant ainsi l'accès aux plus importantes frayères. Ceci a suffi de prétexte pour renoncer à une longueur de capture garantissant la reproduction naturelle. Par la suite, la population en train de diminuer a servi de justification pour des déversements importants de truites arc-en-ciel. Un désintérêt croissant pour le maintien de frayères dans les affluents secondaires a, finalement, contribué à la baisse des captures de 12.000 kg à 3.000 kg entre 1950 et 1980.Les mesures réalisées au cours des dernières années pour restaurer la population de truites lacustres ont du succès. Il s'agit surtout de : — la détermination d'une nouvelle longueur de capture ainsi que de périodes de protection respectant la reproduction des truites migrant à longue et à courte distance,— l'élevage de stocks de géniteurs, — les déversements forcés et effectués surtout en affluents (au lieu du lac,— l'interdiction d'immersions de truites arc-en-ciel,— l'abolition de barrages. Le succès se manifeste par un nombre croissant de truites observées frayant dans les affluents ainsi que par des captures de plus en plus nombreuses faites par la pêche professionnelle.

  12. Various mutations compensate for a deleterious lacZα insert in the replication enhancer of M13 bacteriophage.

    Directory of Open Access Journals (Sweden)

    Emily M Zygiel

    Full Text Available M13 and other members of the Ff class of filamentous bacteriophages have been extensively employed in myriad applications. The Ph.D. series of phage-displayed peptide libraries were constructed from the M13-based vector M13KE. As a direct descendent of M13mp19, M13KE contains the lacZα insert in the intergenic region between genes IV and II, where it interrupts the replication enhancer of the (+ strand origin. Phage carrying this 816-nucleotide insert are viable, but propagate in E. coli at a reduced rate compared to wild-type M13 phage, presumably due to a replication defect caused by the insert. We have previously reported thirteen compensatory mutations in the 5'-untranslated region of gene II, which encodes the replication initiator protein gIIp. Here we report several additional mutations in M13KE that restore a wild-type propagation rate. Several clones from constrained-loop variable peptide libraries were found to have ejected the majority of lacZα gene in order to reconstruct the replication enhancer, albeit with a small scar. In addition, new point mutations in the gene II 5'-untranslated region or the gene IV coding sequence have been spontaneously observed or synthetically engineered. Through phage propagation assays, we demonstrate that all these genetic modifications compensate for the replication defect in M13KE and restore the wild-type propagation rate. We discuss the mechanisms by which the insertion and ejection of the lacZα gene, as well as the mutations in the regulatory region of gene II, influence the efficiency of replication initiation at the (+ strand origin. We also examine the presence and relevance of fast-propagating mutants in phage-displayed peptide libraries.

  13. Induction of lacI- mutations in Escherichia coli cells after single and split-dose irradiation

    International Nuclear Information System (INIS)

    Kozubek, S.; Ryznar, L.

    1992-01-01

    In the lacI system of Escherichia coli, X-ray mutagenesis follows a linear-quadratic curve with suppression; the survival curve is exponential. Dose fractionation leads to nearly complete repair of premutational lesions during an incubation interval of 3.5 h. Repair starts with a delay of 1.5-2 h, suggesting the involvement of an inducible repair/mutation fixation system. The dose-dependence of mutagenesis is described by a simple model assuming two hits being required. A probable explanation might be that the premutagenic lesions consist of two closely spaced lesions on the opposite strands of the DNA molecule. (author)

  14. Structural evidence for induced fit and a mechanism for sugar/H+ symport in LacY

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Guan, Lan; Verner, Gill

    2006-01-01

    Cation-coupled active transport is an essential cellular process found ubiquitously in all living organisms. Here, we present two novel ligand-free X-ray structures of the lactose permease (LacY) of Escherichia coli determined at acidic and neutral pH, and propose a model for the mechanism...... of coupling between lactose and H+ translocation. No sugar-binding site is observed in the absence of ligand, and deprotonation of the key residue Glu269 is associated with ligand binding. Thus, substrate induces formation of the sugar-binding site, as well as the initial step in H+ transduction....

  15. Production of giant gourami Osphronemus goramy Lac. juvenile with different rate of water exchange

    Directory of Open Access Journals (Sweden)

    Tatag Budiardi

    2015-03-01

    Full Text Available ABSTRACTGiant gourami Osphronemus goramy Lac. is one of the most important fresh water fish commodities with increasing production level every year. Water quality management through a proper water exchange both in quantity and quality can be one of the alternatives to support the elevating production. This research was conducted from July to August 2010 at the Aquaculture Production Technology and Management Laboratory, Department of Aquaculture, Faculty of Fisheries and Marine Science, Bogor Agricultural University. The juvenile used was 0.84±0.011 cm in length and 0.017±0.001 cm in weight which reared in nine units of aquaria with a size of 60×29×33 cm3. Silk worm was used as the feed and provided daily at satiation. Water exchange was performed twice a day at a level depending on the treatment, namely 75% (50% at morning and 25% at evening, 100% (50% at morning and evening and 125% (75% at morning and 50% at evening of total water volume. Water exchange at 75%, 100%, and 125%/day resulted in survival rates of 94.11±0.63%; 91.89±2.02%; and 93.89±0.75%; specific growth rates of 7.43±0.15%, 8.58±0.24%, and 9.97±0.18%. Growth rate in length of 1.06±0.06 cm, 1.33±0.04 cm, and 1.55±0.01 cm; coefficient of variation in length of 11.31±1.43%, 9.35±1.46%, and 6.90±2.30%; feed efficiency of 12.47±0.30%, 14.32±1.05%, and 19.67±0.54%. The financial benefits resulted of the process were worth of IDR.351,903.00; IDR.402,302.00; and IDR.464,715.00; whereas R/C ratio of 1.71; 1.80; dan 1.90; BEP of 1,845 unit, 1,645 unit, and 1,517 unit; payback period (PP of 0.97 years, 0.85 years, and 0.74 years; and the cost production as much as IDR.79.90; IDR.82.70; and IDR.82.90/individual, respectively. The treatments were significantly different on several parameters, such as specific growth rate, length of growth rate, feed efficiency at p<0.05. The results of this experiment showed that 125% daily water exchange improved the production

  16. Lactose carrier protein of Escherichia coli. Structure and expression of plasmids carrying the Y gene of the lac operon.

    Science.gov (United States)

    Teather, R M; Bramhall, J; Riede, I; Wright, J K; Fürst, M; Aichele, G; Wilhelm, U; Overath, P

    1980-01-01

    The previously described hybrid plasmid pC7 which carries lacI+O+delta(Z)Y+A+ on a 12.3 X 10(6)-Mr DNA fragment [Teather et al. (1978) Mol. Gen. Genet. 159, 239-248] was partially digested with the restriction endonuclease EcoRI under conditions reducing the recognition sequence to d(A-A-T-T) and ligated to the vector pB322. lac Y-carrying inserts of various sized (Mr 1.5-4.7 X 10(6)) were obtained. Hybrid plasmid pTE18 (2300-base-pair insert) carries part of the I (repressor) gene, the promotor-operator region, part of the Z (beta-galactosidase) gene, the Y (lactose carrier) gene and part of the A (transacetylase) gene. Upon induction of pTE18-harbouring strains the Y-gene product is expressed at a nearly constant rate for several generations and accumulates to a level of 12-16% of the total cytoplasmic membrane protein. Integration into the membrane leads to active carrier as judged by binding and transport measurements.

  17. Water in the Cratonic Mantle: Insights from FTIR Data on Lac De Gras Xenoliths (Slave Craton, Canada)

    Science.gov (United States)

    Peslier, Anne H.; Brandon, Alan D.; Schaffer, Lillian Aurora; O'Reilly, Suzanne Yvette; Griffin, William L.; Morris, Richard V.; Graff, Trevor G.; Agresti, David G.

    2014-01-01

    The mantle lithosphere beneath the cratonic part of continents is the deepest (> 200 km) and oldest (>2-3 Ga) on Earth, remaining a conundrum as to how these cratonic roots could have resisted delamination by asthenospheric convection over time. Water, or trace H incorporated in mineral defects, could be a key player in the evolution of continental lithosphere because it influences melting and rheology of the mantle. Mantle xenoliths from the Lac de Gras kimberlite in the Slave craton were analyzed by FTIR. The cratonic mantle beneath Lac de Gras is stratified with shallow (water contents extending to higher values than those from the shallow ones. The FTIR spectra of olivines from the shallow samples have more prominent Group II OH bands compared to the olivines from the deep samples, consistent with a more oxidized mantle environment. The range of olivine water content is similar to that observed in Kaapvaal craton peridotites at the same depths (129-184 km) but does not extend to as high values as those from Udachnaya (Siberian craton). The Slave, Kaapvaal and Siberian cratons will be compared in terms of water content distribution, controls and role in cratonic root longevity.

  18. 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.

  19. Hydrogen production by Escherichia coli {delta}hycA {delta}lacI using cheese whey as substrate

    Energy Technology Data Exchange (ETDEWEB)

    Rosales-Colunga, Luis Manuel; Ordonez, Leandro G.; De Leon-Rodriguez, Antonio (Division de Biologia Molecular, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, Col. Lomas 4a secc. CP 78216, San Luis Potosi, SLP. Mexico); Razo-Flores, Elias; Alatriste-Mondragon, Felipe (Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, Col. Lomas 4a secc. CP 78216, San Luis Potosi, SLP. Mexico)

    2010-01-15

    This study reports a fermentative hydrogen production by Escherichia coli using cheese whey as substrate. To improve the biohydrogen production, an E. coli {delta}hycA {delta}lacI strain (WDHL) was constructed. The absence of hycA and lacI genes had a positive effect on the biohydrogen production. The strain produced 22% more biohydrogen in a shorter time than the wild-type (WT) strain. A Box-Behnken experimental design was used to optimize pH, temperature and substrate concentration. The optimal initial conditions for biohydrogen production by WDHL strain were pH 7.5, 37 C and 20 g/L of cheese whey. The specific production rate was improved from 3.29 mL H{sub 2}/optical density at 600 nm (OD{sub 600nm}) unit-h produced by WDHL under non-optimal conditions to 5.88 mL H{sub 2}/OD{sub 600nm} unit-h under optimal conditions. Using optimal initial conditions, galactose can be metabolized by WDHL strain. The maximum yield obtained was 2.74 mol H{sub 2}/mol lactose consumed, which is comparable with the yield reached in other hydrogen production processes with Clostridium sp. or mixed cultures. (author)

  20. Dissemination in athymic nude mice of lacZ transfected small cell lung cancer cells identified by X-gal staining

    DEFF Research Database (Denmark)

    Rømer, M U; Christiansen, J; Brünner, N

    1995-01-01

    The small cell lung cancer cell lines GLC-2 and DMS 456 were genetically labeled with the lacZ gene and examined for invasive and metastatic potential in META/Bom nude mice. The lacZ gene encodes the enzyme beta-D- galactosidase, and cells expressing this enzyme were identified by staining...... with the chromogenic substrate X-gal. lacZ expressing cells were investigated after subcutaneous (s.c.) inoculation and intravenous (i.v.) injection. The X-gal detection of beta-D-galactosidase activity proved to be a rapid and easy means for specific and highly sensitive identification of metastases. All primary s.......c. tumors stained by X-gal. The primary tumors of GLC-2 regularly demonstrated local invasive growth and produced multiple metastases in several organs. In contrast, primary DMS 456 tumors only occasionally demonstrated local invasion and very rarely generated secondary foci. No experimental metastases were...

  1. Distinct roles of two ceramide synthases, CaLag1p and CaLac1p, in the morphogenesis of Candida albicans

    DEFF Research Database (Denmark)

    Cheon, Seon Ah; Bal, Jyotiranjan; Song, Yunkyoung

    2012-01-01

    p) and Lac1p (CaLac1p) are functionally distinct. Lack of CaLag1p, but not CaLac1p, caused severe defects in the growth and hyphal morphogenesis of C. albicans. Deletion of CaLAG1 decreased expression of the hypha-specific HWP1 and ECE1 genes. Moreover, overexpression of CaLAG1 induced pseudohyphal...... growth in this organism under non-hypha-inducing conditions, suggesting that CaLag1p is necessary for relaying signals to induce hypha-specific gene expression. Analysis of ceramide and sphingolipid composition revealed that CaLag1p predominantly synthesizes ceramides with C24:0/C26:0 fatty acid moieties...

  2. Le lac Titicaca: histoire perdue d'une mer intérieure

    Directory of Open Access Journals (Sweden)

    1992-01-01

    Full Text Available Cet article tente de reconstruire l’histoire de la région du lac Titicaca et de son peuplement pour la période précédant l’arrivée des espagnols. Á cet effet, nous avons utilisé une approche multidisciplinaire (sédimentologie, archéologie, mythologie qui autorise, depuis l’amont et dans la longue durée, un nouvel éclairage des données historiques du XVIe siècle. Malgré les changements climatiques et politiques ayant affecté les rives du Titicaca avant la Conquête espagnole, il existe une continuité historique qui va de la civilisation de Pukará à Hatuncolla en passant par Tiwanaku. Si la documentation espagnole ne rend pas compte de l’importance des anciennes populations riveraines et notamment des pukinas, c’est qu’il était de l’intérêt des envahisseurs successifs (aymaras, incas, espagnols de l’occulter. EL LAGO TITICACA: HISTORIA PERDIDA DE UN MAR INTERIOR. Este artículo constituye un intento de reconstrucción de la historia del lago Titicaca y de su poblamiento por el período que precede la llegada de los españoles. En esta perspectiva, hemos utilizado una aproximación multidisciplinaria (sedimentología, arqueología, mitología que autoriza una nueva lectura de las fuentes históricas del siglo XVI, a partir de datos remotos y en la larga duración. A pesar de los cambios climáticos y políticos que afectaron las orillas del Titicaca antes de la Conquista española, existe una continuidad histórica que va de la cultura de Pukará hasta Hatuncolla (pasando por Tiwanaku. Si la documentación española no toma en cuenta la importancia de las antiguas poblaciones lacustres, particularmente los pukinas, es porque el interés de sus sucesivos vencedores (aymara, incas, españoles era de ocultarla. THE TITICACA LAKE: HISTORY LOST IN THE CENTER OF A DEEP IMMENSITY. This article comprises an attempt to reconstruct the Titicaca Lake history and its colonization during the period preceding the Spanish arrival. On

  3. Accretion disk emission from a BL Lacertae object

    International Nuclear Information System (INIS)

    Wandel, A.; Urry, C.M.

    1991-01-01

    It is suggested here that the UV and X-ray emission of BL Lac objects may originate in an accretion disk. Using detailed calculations of accretion disk spectra, the best-measured ultraviolet and soft X-ray spectra of the BL Lac object PKS 2155-304 are fitted, and the mass and accretion rate required is determined. The ultraviolet through soft X-ray continuum is well fitted by the spectrum of an accretion disk, but near-Eddington accretion rates are required to produce the soft X-ray excess. A hot disk or corona could Comptonize soft photons from the cool disk and produce the observed power-law spectrum in the 1-10 keV range. The dynamic time scale in the disk regions that contribute most of the observed ultraviolet and soft X-ray photons are consistent with the respective time scales for intensity variations observed in these two wave bands; the mass derived from fitting the continuum spectrum is consistent with the limit derived from the fastest hard X-ray variability. 37 refs

  4. X-ray studies of BL Lacertae objects

    International Nuclear Information System (INIS)

    Madejski, G.M.

    1986-01-01

    This thesis presents spectral x-ray data for BL Lac objects observed by the IPC and MPC aboard the Einstein Observatory and interprets that data in a context of their overall radiation spectra using synchrotron and synchrotron self-Compton models. The objects considered are: OJ 287, PKS 0735 + 178, I Zw 186, PKS 0548-322, Mkn 180, BL Lacertae, PKS 2155-304, H 0414-009 and H 0323 + 022. X-ray spectra of BL Lac objects are well described by a power law model with a low energy cutoff due to absorption within the own Galaxy. The best fit values of the energy spectral index α in the IPC (0.2-4.0 keV) band range from 0.73 to 2.35, with a mean of 1.2 and rms spread of 0.51. No single, universal index can fit the spectra of all objects. For all objects except PKS 0735 + 178, the x-ray spectrum is an extrapolation of the infrared/optical UV spectrum; in PKS 0735 + 178, the x-ray spectrum lies significantly below such an extrapolation. The overall electromagnetic distribution in those objects is interpreted as arising due to the synchrotron process in at least two spatial regions, with sizes respectively ∼10 18 cm for the radio component and ∼10 16 cm for the optical component. In objects where the x-ray spectrum lies on the extrapolation of the infrared-optical-ultraviolet spectrum, the x-ray emission is interpreted also to be due to the synchrotron process

  5. Complete Genomes of Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, Two Phylogenetically Distinct Probiotics

    Science.gov (United States)

    Ramya, T. N. C.; Subramanian, Srikrishna

    2016-01-01

    Several spore-forming strains of Bacillus are marketed as probiotics due to their ability to survive harsh gastrointestinal conditions and confer health benefits to the host. We report the complete genomes of two commercially available probiotics, Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, and compare them with the genomes of other Bacillus and Lactobacillus. The taxonomic position of both organisms was established with a maximum-likelihood tree based on twenty six housekeeping proteins. Analysis of all probiotic strains of Bacillus and Lactobacillus reveal that the essential sporulation proteins are conserved in all Bacillus probiotic strains while they are absent in Lactobacillus spp. We identified various antibiotic resistance, stress-related, and adhesion-related domains in these organisms, which likely provide support in exerting probiotic action by enabling adhesion to host epithelial cells and survival during antibiotic treatment and harsh conditions. PMID:27258038

  6. Complete Genomes of Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, Two Phylogenetically Distinct Probiotics.

    Directory of Open Access Journals (Sweden)

    Indu Khatri

    Full Text Available Several spore-forming strains of Bacillus are marketed as probiotics due to their ability to survive harsh gastrointestinal conditions and confer health benefits to the host. We report the complete genomes of two commercially available probiotics, Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, and compare them with the genomes of other Bacillus and Lactobacillus. The taxonomic position of both organisms was established with a maximum-likelihood tree based on twenty six housekeeping proteins. Analysis of all probiotic strains of Bacillus and Lactobacillus reveal that the essential sporulation proteins are conserved in all Bacillus probiotic strains while they are absent in Lactobacillus spp. We identified various antibiotic resistance, stress-related, and adhesion-related domains in these organisms, which likely provide support in exerting probiotic action by enabling adhesion to host epithelial cells and survival during antibiotic treatment and harsh conditions.

  7. Complete Genomes of Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, Two Phylogenetically Distinct Probiotics.

    Science.gov (United States)

    Khatri, Indu; Sharma, Shailza; Ramya, T N C; Subramanian, Srikrishna

    2016-01-01

    Several spore-forming strains of Bacillus are marketed as probiotics due to their ability to survive harsh gastrointestinal conditions and confer health benefits to the host. We report the complete genomes of two commercially available probiotics, Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, and compare them with the genomes of other Bacillus and Lactobacillus. The taxonomic position of both organisms was established with a maximum-likelihood tree based on twenty six housekeeping proteins. Analysis of all probiotic strains of Bacillus and Lactobacillus reveal that the essential sporulation proteins are conserved in all Bacillus probiotic strains while they are absent in Lactobacillus spp. We identified various antibiotic resistance, stress-related, and adhesion-related domains in these organisms, which likely provide support in exerting probiotic action by enabling adhesion to host epithelial cells and survival during antibiotic treatment and harsh conditions.

  8. Typha control efficiency of a weed-cutting boat in the Lac de Guiers in Senegal : A preliminary study on mowing speed and re-growth capacity

    NARCIS (Netherlands)

    Hellsten, S.; Dieme, C.; Mbengue, M.; Janauer, G.A.; Hollander, den N.G.; Pieterse, A.H.

    1999-01-01

    Prolific growth of Typha australis in the lower part of the Senegal River and the Lac de Guiers resulted from changed ecological conditions following the construction of two high dams in the Senegal River. Fluctuation of the water level has decreased markedly and the water has changed from brackish

  9. Additional new species of Hypostomus Lacépède, 1803, from Surinam; with remarks on the apparent „gymnorhynchus-complex” (Siluriformes, Loricariidae)

    NARCIS (Netherlands)

    Boeseman, M.

    1969-01-01

    Two new Surinam species of Hypostomus Lacépède are described, and their relationship is discussed; a group of three forms from eastern Surinam and (French) Guyane (gymnorhynchus-complex) is reconsidered; the species H. plecostomus (Linnaeus) is reported to hitherto survive in the lacustrine

  10. Food-grade host/vector expression system for Lactobacillus casei based on complementation of plasmid-associated phospho-beta-galactosidase gene lacG.

    Science.gov (United States)

    Takala, T M; Saris, P E J; Tynkkynen, S S H

    2003-01-01

    A new food-grade host/vector system for Lactobacillus casei based on lactose selection was constructed. The wild-type non-starter host Lb. casei strain E utilizes lactose via a plasmid-encoded phosphotransferase system. For food-grade cloning, a stable lactose-deficient mutant was constructed by deleting a 141-bp fragment from the phospho-beta-galactosidase gene lacG via gene replacement. The deletion resulted in an inactive phospho-beta-galactosidase enzyme with an internal in-frame deletion of 47 amino acids. A complementation plasmid was constructed containing a replicon from Lactococcus lactis, the lacG gene from Lb. casei, and the constitutive promoter of pepR for lacG expression from Lb. rhamnosus. The expression of the lacG gene from the resulting food-grade plasmid pLEB600 restored the ability of the lactose-negative mutant strain to grow on lactose to the wild-type level. The vector pLEB600 was used for expression of the proline iminopeptidase gene pepI from Lb. helveticus in Lb. casei. The results show that the food-grade expression system reported in this paper can be used for expression of foreign genes in Lb. casei.

  11. Tunable Control of an Escherichia coli Expression System for the Overproduction of Membrane Proteins by Titrated Expression of a Mutant lac Repressor.

    Science.gov (United States)

    Kim, Seong Keun; Lee, Dae-Hee; Kim, Oh Cheol; Kim, Jihyun F; Yoon, Sung Ho

    2017-09-15

    Most inducible expression systems suffer from growth defects, leaky basal induction, and inhomogeneous expression levels within a host cell population. These difficulties are most prominent with the overproduction of membrane proteins that are toxic to host cells. Here, we developed an Escherichia coli inducible expression system for membrane protein production based on titrated expression of a mutant lac repressor (mLacI). Performance of the mLacI inducible system was evaluated in conjunction with commonly used lac operator-based expression vectors using a T7 or tac promoter. Remarkably, expression of a target gene can be titrated by the dose-dependent addition of l-rhamnose, and the expression levels were homogeneous in the cell population. The developed system was successfully applied to overexpress three membrane proteins that were otherwise difficult to produce in E. coli. This gene expression control system can be easily applied to a broad range of existing protein expression systems and should be useful in constructing genetic circuits that require precise output signals.

  12. Deposition mechanism and microstructure of laser-assisted cold-sprayed (LACS) Al-12 wt.%Si coatings: effects of laser power

    CSIR Research Space (South Africa)

    Olakanmi, EO

    2013-06-01

    Full Text Available at the substrate and build up a coating. To circumvent the processing problems associated with cold-spray (CS) deposition of low-temperature, corrosion-resistant Al-12 wt.%Si coatings, a preliminary investigation detailing the effect of laser power on its LACS...

  13. De Paris à Lyon. Les mutations éditoriales du «Lancelot du Lac»

    Directory of Open Access Journals (Sweden)

    Gaëlle Burg

    2015-07-01

    Full Text Available Lancelot du Lac est le premier roman arthurien imprimé à la Renais­sance. Dans sa première édition parue en 1488, qui réunit deux imprimeurs (Jean Le Bourgeois à Rouen et Jean Du Pré à Paris, un découpage et un prologue inédits sont ajoutés par le remanieur. Le texte sera réédité six fois par divers imprimeurs-libraires parisiens jusqu’en 1533. L’édition de luxe d’Antoine Vérard (1494, destinée au roi Charles VIII, présente d’importantes modifications effectuées dans un but commercial. Après une longue période d’accalmie qui signe le début du déclin de la vogue des romans de chevalerie médiévaux, Benoît Rigaud publie à Lyon, sous une forme considérablement abrégée, la dernière édition connue du Lancelot au XVIe siècle (1591. Si elle ne présente que peu d’intérêt littéraire, elle apporte cependant des informations concernant les pratiques éditoriales et les goûts du  lecteur de la fin du XVIe siècle. De Paris à Lyon, entre renaissance et déclin, le parcours éditorial d’un incontournable roman arthurien.Lancelot du Lac is the editio princeps of an Arthurian romance in Renaissance France. The first edition in 1488, which brings together two printers (Jean Le Bourgeois from Rouen and Jean Du Pré from Paris, offers original arrangement and prologue added by the compositor. The text will be published six times by various printers and booksellers in Paris until 1533. The luxurious edition from Antoine Vérard (1494 dedicated to King Charles VIII provides interesting transformations in commercial purposes. After a long time without edition, showing the beginning of chivalry literature’s decline, Benoît Rigaud publish in Lyon, in a greatly abbreviated form, the last known edition of Lancelot in the XVIth century (1591. If it presents no literary interest, it provides nevertheless informations about editorial practices and reader’s tastes from the end of Renaissance France. From Paris to

  14. Effect of the partial NaCl substitution by other chloride salts on the volatile profile during the ripening of dry-cured lacón

    Directory of Open Access Journals (Sweden)

    Domínguez, R.

    2016-06-01

    Full Text Available The influence of three salting treatments (treatment II: 50% NaCl-50% KCl; III: 45% NaCl-25% KCl-20% CaCl2-10% MgCl2; IV: 30% NaCl-50% KCl-15% CaCl2-5% MgCl2 on the formation of volatile compounds throughout the process was studied and compared to those of a control “lacón” (treatment I: 100% NaCl. There was an intense formation of volatile compounds throughout the processing, particularly during the dry-ripening stage. The most abundant chemical family in all the formulations, in the final product was hydrocarbons followed by aldehydes. The total volatile compound release was more intense in the control “lacóns” (1164 AU_106·g-1dry matter than in “lacóns” from formulations II, III and IV (817-891 AUx106·g-1dry matter. The “lacóns” from formulation I showed the highest amounts of aldehydes. The “lacóns” from formulations I and II presented the highest amounts of hydrocarbons. The main conclusion is that the replacement of NaCl produces changes in the volatile profile and could be affect the aroma of “lacón”.Se estudió la influencia de tres tratamientos de salado (tratamiento II: 50 % NaCl-50 % KCl; III: 45 % NaCl-25 % KCl-20 % CaCl2-10 % MgCl2; IV: 30 % NaCl-50 % KCl-15 % CaCl2-5 % MgCl2 en la formación de compuestos volátiles durante la elaboración de lacón, en comparación con un control (tratamiento I: 100 % NaCl. Hubo una intensa formación de compuestos volátiles durante el procesado, principalmente durante la fase de secado-maduración. La familia química más abundante en el producto final fueron los hidrocarbonos, seguidos por los aldehídos. La liberación de volátiles fue más intensa en los lacones control (1164 AU_106·g-1 materia seca que en los otros lacones (817-891 AUx106· g-1 materia seca. Los lacones de la formulación I mostraron las mayores cantidades de aldehídos, y los lacones de las formulaciones I y II presentaron los mayores contenidos de hidrocarburos. La principal conclusi

  15. A Pleistocene record of a rare endemic gymnosperm, Neocallitropsis pancheri (Cupressaceae), from the Plaine des Lacs, New Caledonia

    International Nuclear Information System (INIS)

    Suprin, B.; Hope, G.

    2001-01-01

    A log found submerged in a small lake in south east New Caledonia has been identified as the now rare endemic conifer Neocallitropsis pancheri (Carr.) Laubenf. (Cupressaceae). Tree ring counts are in reasonable agreement with two radiocarbon dates from the centre and outer wood of the log, indicating an age at death of about 250 years. The tree lived about 12,000 C14 years ago and was as large as modern individuals of presumed similar age. Widespread erosion and the replacement of mixed rainforest by Gymnostoma dominated maquis, associated with episodes of fire, occurred in this area for an unknown period after 25,000 BP. The growth of this moisture dependant and fire sensitive gymnosperm by 12,000 BP suggests that a moister and more stable climate may have been re-established before the start of the Holocene. The species is now almost removed from the Plaine des Lacs, possibly being excluded by widespread natural fires in the Holocene, and those associated with European logging in the early colonial period

  16. Advances in the graphitization protocol at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Macario, Kita D., E-mail: kitamacario@gmail.com [Departamento de Física, Instituto deFísica, Universidade Federal Fluminense, Campus da Praia Vermelha, Av. Gal. Milton Tavares de Souza s/n°, Niterói, RJ, 24210-346 (Brazil); Oliveira, Fabiana M. [Departamento de Física, Instituto deFísica, Universidade Federal Fluminense, Campus da Praia Vermelha, Av. Gal. Milton Tavares de Souza s/n°, Niterói, RJ, 24210-346 (Brazil); Carvalho, Carla [Departamento de Geoquímica, Instituto de Química, Universidade Federal Fluminense, Campus do Valonguinho, Outeiro São João Batista, s/n°, Niterói, RJ, 24020-150 (Brazil); Santos, Guaciara M.; Xu, Xiaomei [Department of Earth System Science, B321 Croul Hall, University of California Irvine, Irvine, CA, 92697-3100 (United States); Chanca, Ingrid S.; Alves, Eduardo Q.; Jou, Renata M.; Oliveira, Maria Isabela; Pereira, Bruna B.; Moreira, Vinicius; Muniz, Marcelo C.; Linares, Roberto; Gomes, Paulo Roberto Silveira; Meigikos dos Anjos, Roberto [Departamento de Física, Instituto deFísica, Universidade Federal Fluminense, Campus da Praia Vermelha, Av. Gal. Milton Tavares de Souza s/n°, Niterói, RJ, 24210-346 (Brazil); and others

    2015-10-15

    In this paper, we summarize the sample preparation methods currently used at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil. We also report on a series of results with regards to the graphitization protocol. Tests with different temperatures and baking times were performed, and carbon stable isotope ratios of graphite were measured by an EA–IRMS (elemental analyzer coupled with an isotopic ratio mass spectrometer) to infer the completeness of the graphitization reaction. We monitored the muffle furnace temperature using an independent thermocouple and found a −60 °C offset, which may have caused the lower graphitization yields (detected from the large isotopic fractionation on several reference materials targets). At a temperature of 520 °C, the isotopic fractionation in the graphitization reaction was systematically lower (−5‰ in average) and the overall scattering was reduced. As long as isotopic fractionation corrections are made using the online stable isotopes ratios provided by the AMS system, the accuracy of the {sup 14}C results should be maintained.

  17. Comparative genomics of CytR, an unusual member of the LacI family of transcription factors.

    Directory of Open Access Journals (Sweden)

    Natalia V Sernova

    Full Text Available CytR is a transcription regulator from the LacI family, present in some gamma-proteobacteria including Escherichia coli and known not only for its cellular role, control of transport and utilization of nucleosides, but for a number of unusual structural properties. The present study addressed three related problems: structure of CytR-binding sites and motifs, their evolutionary conservation, and identification of new members of the CytR regulon. While the majority of CytR-binding sites are imperfect inverted repeats situated between binding sites for another transcription factor, CRP, other architectures were observed, in particular, direct repeats. While the similarity between sites for different genes in one genome is rather low, and hence the consensus motif is weak, there is high conservation of orthologous sites in different genomes (mainly in the Enterobacteriales arguing for the presence of specific CytR-DNA contacts. On larger evolutionary distances candidate CytR sites may migrate but the approximate distance between flanking CRP sites tends to be conserved, which demonstrates that the overall structure of the CRP-CytR-DNA complex is gene-specific. The analysis yielded candidate CytR-binding sites for orthologs of known regulon members in less studied genomes of the Enterobacteriales and Vibrionales and identified a new candidate member of the CytR regulon, encoding a transporter named NupT (YcdZ.

  18. A new pale-spotted species of Hypostomus Lacépède (Siluriformes: Loricariidae from the rio Tocantins and rio Xingu basins in central Brazil

    Directory of Open Access Journals (Sweden)

    Cláudio H. Zawadzki

    Full Text Available A new species of the genus Hypostomus Lacépède (Siluriformes, Loricariidae from rio Tocantins and rio Xingu basins in central Brazil, is described. The new species is distinguished from its congeners by a unique combination of pale blotches over a darker background on head, body and fins, and conspicuous keels on head, predorsal region and lateral plates. Comments on the pale-spotted species of Hypostomus are provided.

  19. First Nustar Observations of the Bl Lac-Type Blazar Pks 2155-304: Constraints on the Jet Content and Distribution of Radiating Particles

    DEFF Research Database (Denmark)

    Madejski, G. M.; Nalewajko, K.; Madsen, K. K.

    2016-01-01

    We report the first hard X-ray observations with NuSTAR of the BL Lac-type blazar PKS 2155-304, augmented with soft X-ray data from XMM-Newton and γ-ray data from the Fermi Large Area Telescope, obtained in 2013 April when the source was in a very low flux state. A joint NuSTAR and XMM spectrum, ...

  20. Mutagenicity of the peroxisome proliferators clofibrate, Wyeth 14,643 and di-2-ethylhexyl phthalate in the lacZ plasmid-based transgenic mouse mutation assay

    Directory of Open Access Journals (Sweden)

    Boerrigter Michaël

    2004-01-01

    Full Text Available Abstract Background Peroxisome proliferators are considered rodent carcinogens that are putative human non-carcinogens based on the presumed absence of direct genetic toxicity in rodent and human cells and the resistance of human cells to the induction of peroxisomes by peroxisome proliferators. The highly sensitive lacZ plasmid-based transgenic mouse mutation assay was employed to investigate the mutagenicity of several peroxisome proliferators based on several lines of evidence suggesting that these agents may in fact exert a genotoxic effect. Methods Male and female lacZ-plasmid based transgenic mice were treated at 4 months of age with 6 doses of 2,333 mg di-2-ethylhexyl phthalate (DHEP, 200 mg Wyeth-14,643, or 90 mg clofibrate per kg of bodyweight, respectively, over a two-week period. Control animals were treated with the respective vehicles only (35% propyl glycol for DEHP and Wyeth-14,643 treatment controls and sterile water for clofibrate treatment controls. The mutant frequency in liver, kidney and spleen DNA was determined as the proportion of retrieved mutant and wild-type lacZ plasmids expressed in Escherichia Coli C host cells employing a positive selection system for mutant plasmids. Results Exposure to DEHP or Wyeth-14,643 significantly increased the mutant frequency in liver, but not in kidney or spleen, of both female and male mice. Treatment with clofibrate did not lead to an increased mutant frequency in any of the organs studied. Conclusion The results indicate that some peroxisome proliferators display an organ-specific mutagenicity in lacZ plasmid-based transgenic mice consistent with historical observations of organ- and compound-specific carcinogenicity.

  1. ENDOR determination of the proton positions around Gd3+ in La(C2H5SO4)3.9H2O

    International Nuclear Information System (INIS)

    Beer, R. de; Biesboer, F.; Ormondt, D. van

    1976-01-01

    The water proton positions around Gd 3+ in La(C 2 H 5 SO 4 ) 3 .9H 2 O have been determined by means of ENDOR. The positions of the nearest neighbour water oxygens are discussed on the basis of a superposition model analysis of the ratios b 2 0 /A 2 0 2 >, b 6 6 /b 6 0 and mod(A 6 6 )modA 6 0 . (Auth.)

  2. Louisiana SIP: LAC 33:III Ch 2147. Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 2011-08-04 (LAd34) to 2017-09-27

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch 2147. Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 2011-08-04 (LAd34) to 2017-09-27

  3. Assessment of aquifer properties, evapotranspiration, and the effects of ditching in the Stoney Brook watershed, Fond du Lac Reservation, Minnesota, 2006-9

    Science.gov (United States)

    Jones, Perry M.; Tomasek, Abigail A.

    2015-01-01

    The U.S. Geological Survey, in cooperation with the Fond du Lac Band of Lake Superior Chippewa, assessed hydraulic properties of geologic material, recharge, and evapotranspiration, and the effects of ditching on the groundwater resources in the Stoney Brook watershed in the Fond du Lac Reservation. Geologic, groundwater, and surface-water data were collected during 2006–9 to estimate hydrologic properties in the watershed. Streamflow and groundwater levels in the shallow glacial deposits in the Stoney Brook watershed were analyzed to estimate groundwater-flow directions, groundwater recharge, and evapotranspiration within the watershed and to assess the effect of ditches on surrounding groundwater resources. Groundwater, streamflow, and precipitation data collected during the study (2006–9) can be used to update the U.S. Department of Agriculture’s Natural Resource Conservation Service and Fond du Lac Resource Management Division surface-water models, which are used to evaluate the effect of proposed adjustments to the ditching system on streamflow on wild rice production and aquatic habitats.

  4. 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...... as a unique opportunity for studying the interchange between these two forms of fetishism and their respective phenomenologies. Finally, returning to Serres, I briefly consider the theoretical consequences of introducing the fashion object as a quasi-object.......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....... These two phenomenologies are, so I argue, essential to quasi-object theory, yet largely ignored by Serres’ sociological interpreters. They correspond with the two different theories of fetishism found in Marx and Durkheim, respectively. In the second half of the article, I introduce the fashion object...

  5. Karakterisasi Molekuler Ikan Gurami Soang (Osphronemus goramy Lac. berbeda uuran menggunakan Pcr-Rflp Gen Sitokrom C Oksidase 1

    Directory of Open Access Journals (Sweden)

    Siti Nur Azizah

    2017-01-01

    Full Text Available Gourami (Osprhronemus goramy Lac. is a  freshwater fish that is  widely cultivated in Indonesia, particularly by fish farmer in Java. Soang strain has a faster growth rate than other strains. However, the fry that derived from a single cohort (generated from a single spawning shows various sizes even in the same age because they have different growth rate. Differences in growth rate may occur due to differences in metabolic capabilities especially cellular respiration. Different rate of respiration can be assumed to be due to differences in the genetic component, especially on their cytochrome c oxidase 1 gene (CO1. Therefore this study aimed to determine whether there are differences in PCR-RFLP marker CO1 gene among different sizes of gourami soang strain from the same cohort so that can be used to analyze genetic diversity. This study used survey method by applying purposive random sampling. Four restriction enzymes were used  during the  research. Molecular characters were defined descriptively based on the appearance of restriction fragment on agarose gel. The result showed that soang strain which used in this study had monomorphics allele on their CO1-HindIII. PstI, BamHI, and EcoRI, could not cut the PCR products and results no RFLP markers. So that genetic variation in the used CO1 gene fragment could not be detected using HindIII, Pst1, BamH1 and EcoR1 enzymes. The three different sizes of soang strain had similar alleles or homozygous, meaning that heterozigocity value was 0 (zero. Therefore, the CO1 gene in this study could not be used as molecular character to differentiate different sizes of gourami soang strain from the same cohort.

  6. 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.)

  7. Simulation of groundwater flow and interaction of groundwater and surface water on the Lac du Flambeau Reservation, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Fienen, Michael N.; Hunt, Randall J.

    2014-01-01

    The Lac du Flambeau Band of Lake Superior Chippewa and Indian Health Service are interested in improving the understanding of groundwater flow and groundwater/surface-water interaction on the Lac du Flambeau Reservation (Reservation) in southwest Vilas County and southeast Iron County, Wisconsin, with particular interest in an understanding of the potential for contamination of groundwater supply wells and the fate of wastewater that is infiltrated from treatment lagoons on the Reservation. This report describes the construction, calibration, and application of a regional groundwater flow model used to simulate the shallow groundwater flow system of the Reservation and water-quality results for groundwater and surface-water samples collected near a system of waste-water-treatment lagoons. Groundwater flows through a permeable glacial aquifer that ranges in thickness from 60 to more than 200 feet (ft). Seepage and drainage lakes are common in the area and influence groundwater flow patterns on the Reservation. A two-dimensional, steady-state analytic element groundwater flow model was constructed using the program GFLOW. The model was calibrated by matching target water levels and stream base flows through the use of the parameter-estimation program, PEST. Simulated results illustrate that groundwater flow within most of the Reservation is toward the Bear River and the chain of lakes that feed the Bear River. Results of analyses of groundwater and surface-water samples collected downgradient from the wastewater infiltration lagoons show elevated levels of ammonia and dissolved phosphorus. In addition, wastewater indicator chemicals detected in three downgradient wells and a small downgradient stream indicate that infiltrated wastewater is moving southwest of the lagoons toward Moss Lake. Potential effects of extended wet and dry periods (within historical ranges) were evaluated by adjusting precipitation and groundwater recharge in the model and comparing the

  8. Mef2c-F10N enhancer driven β-galactosidase (LacZ) and Cre recombinase mice facilitate analyses of gene function and lineage fate in neural crest cells.

    Science.gov (United States)

    Aoto, Kazushi; Sandell, Lisa L; Butler Tjaden, Naomi E; Yuen, Kobe C; Watt, Kristin E Noack; Black, Brian L; Durnin, Michael; Trainor, Paul A

    2015-06-01

    Neural crest cells (NCC) comprise a multipotent, migratory stem cell and progenitor population that gives rise to numerous cell and tissue types within a developing embryo, including craniofacial bone and cartilage, neurons and glia of the peripheral nervous system, and melanocytes within the skin. Here we describe two novel stable transgenic mouse lines suitable for lineage tracing and analysis of gene function in NCC. Firstly, using the F10N enhancer of the Mef2c gene (Mef2c-F10N) linked to LacZ, we generated transgenic mice (Mef2c-F10N-LacZ) that express LacZ in the majority, if not all migrating NCC that delaminate from the neural tube. Mef2c-F10N-LacZ then continues to be expressed primarily in neurogenic, gliogenic and melanocytic NCC and their derivatives, but not in ectomesenchymal derivatives. Secondly, we used the same Mef2c-F10N enhancer together with Cre recombinase to generate transgenic mice (Mef2c-F10N-Cre) that can be used to indelibly label, or alter gene function in, migrating NCC and their derivatives. At early stages of development, Mef2c-F10N-LacZ and Mef2c-F10N-Cre label NCC in a pattern similar to Wnt1-Cre mice, with the exception that Mef2c-F10N-LacZ and Mef2c-F10N-Cre specifically label NCC that have delaminated from the neural plate, while premigratory NCC are not labeled. Thus, our Mef2c-F10N-LacZ and Mef2c-F10N-Cre transgenic mice provide new resources for tracing migratory NCC and analyzing gene function in migrating and differentiating NCC independently of NCC formation. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Quasi-simultaneous ultraviolet, optical, and infrared observations of the BL Lacertae object PKS 0048-09

    International Nuclear Information System (INIS)

    Falomo, R.; Bouchet, P.; Maraschi, L.; Treves, A.; Tanzi, E.G.

    1988-01-01

    This paper reports on quasi-simultaneous UV, optical, and IR observations of the BL Lac object PKS 0048-09, carried out on January 7-9, 1987, when the object was in a moderately high optical state. The data were used to derive a detailed energy distribution from about 10 to the 14th to about 2.5 x 10 to the 15th Hz. A comparison of observations obtained on January 7-9, 1987, with observations on September 12, 1986, pertaining to a lower state of the source, indicates spectral hardening with increasing intensity on time scales of months. 26 references

  10. Quasi-simultaneous ultraviolet, optical, and infrared observations of the BL Lacertae object PKS 0048-09

    Energy Technology Data Exchange (ETDEWEB)

    Falomo, R.; Bouchet, P.; Maraschi, L.; Treves, A.; Tanzi, E.G.

    1988-12-01

    This paper reports on quasi-simultaneous UV, optical, and IR observations of the BL Lac object PKS 0048-09, carried out on January 7-9, 1987, when the object was in a moderately high optical state. The data were used to derive a detailed energy distribution from about 10 to the 14th to about 2.5 x 10 to the 15th Hz. A comparison of observations obtained on January 7-9, 1987, with observations on September 12, 1986, pertaining to a lower state of the source, indicates spectral hardening with increasing intensity on time scales of months. 26 references.

  11. Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique

    International Nuclear Information System (INIS)

    Abdel-Kareem, O.; Eltokhy, A.; Harith, M. A.

    2011-01-01

    This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

  12. Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique

    Science.gov (United States)

    Abdel-Kareem, O.; Eltokhy, A.; Harith, M. A.

    2011-09-01

    This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

  13. Three new BL Lacertae objects in the Palomar-Green survey

    Science.gov (United States)

    Fleming, Thomas A.; Green, Richard F.; Jannuzi, Buell T.; Liebert, James; Smith, Paul S.; Fink, Henner

    1993-01-01

    We have identified three BL Lacertae objects in the Palomar-Green Survey which were previously misclassified as DC white dwarfs, namely PG 1246+586, PG 1424+240, and PG 1437+398. Our reclassification is based on the detection of these objects as x-ray sources in the ROSAT all-sky survey and upon our subsequent detection of intrinsic linearly polarized and variable optical emission from these sources. As a result of the ROSAT survey, the number of identified BL Lac objects in the Palomar-Green catalog of UV excess objects has been doubled. Corrected optical positions are presented for PG 1246+586 and PG 1437+398.

  14. Somatostatin receptor 2 knockout/lacZ knockin mice show impaired motor coordination and reveal sites of somatostatin action within the striatum.

    Science.gov (United States)

    Allen, Jeremy P; Hathway, Gareth J; Clarke, Neil J; Jowett, Mike I; Topps, Stephanie; Kendrick, Keith M; Humphrey, Patrick P A; Wilkinson, Lawrence S; Emson, Piers C

    2003-05-01

    The peptide somatostatin can modulate the functional output of the basal ganglia. The exact sites and mechanisms of this action, however, are poorly understood, and the physiological context in which somatostatin acts is unknown. Somatostatin acts as a neuromodulator via a family of five 7-transmembrane G protein-coupled receptors, SSTR1-5, one of which, SSTR2, is known to be functional in the striatum. We have investigated the role of SSTR2 in basal ganglia function using mice in which Sstr2 has been inactivated and replaced by the lacZ reporter gene. Analysis of Sstr2lacZ expression in the brain by beta-galactosidase histochemistry demonstrated a widespread pattern of expression. By comparison to previously published in situ hybridization and immunohistochemical data, Sstr2lacZ expression was shown to accurately recapitulate that of Sstr2 and thus provided a highly sensitive model to investigate cell-type-specific expression of Sstr2. In the striatum, Sstr2 expression was identified in medium spiny projection neurons restricted to the matrix compartment and in cholinergic interneurons. Sstr2 expression was not detected in any other nuclei of the basal ganglia except for a sparse number of nondopaminergic neurons in the substantia nigra. Microdialysis in the striatum showed Sstr2-null mice were selectively refractory to somatostatin-induced dopamine and glutamate release. In behavioural tests, Sstr2-null mice showed normal levels of locomotor activity and normal coordination in undemanding tasks. However, in beam-walking, a test of fine motor control, Sstr2-null mice were severely impaired. Together these data implicate an important neuromodulatory role for SSTR2 in the striatum.

  15. Specification of Concurrent Objects

    DEFF Research Database (Denmark)

    Sørensen, Morten U.

    relation over two objects and an event. In the model, objects can be composed by parallel composition, encapsulation, and hiding of operations. Refinement between objects is defined as fair trace inclusion.A specification language is presented where objects can be specified operationally by abstract...

  16. Paradigms in object recognition

    International Nuclear Information System (INIS)

    Mutihac, R.; Mutihac, R.C.

    1999-09-01

    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)

  17. BL Lacertae objects

    International Nuclear Information System (INIS)

    Disney, M.J.; Veron, P.

    1977-01-01

    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

  18. Designing the Object Game

    DEFF Research Database (Denmark)

    Filip, Diane; Lindegaard, Hanne

    2016-01-01

    The Object Game is an exploratory design game and an experiment of developing a tangible object that can spark dialogue and retrospection between collaborative partners and act as a boundary object. The objective of this article is to show and elaborate on the development of the Object Game......, and to provide case examples of the game in action. The Object Game has two parts – Story-building and Co-rating of objects – with the aim of stimulating a collaborative reflection on knowledge sharing with different objects. In Story-building, the participants visualize their knowledge sharing process...... these facilitated knowledge transfer, knowledge exchange, knowledge generation, and knowledge integration. The participants collaborative reflected on their use of different objects for knowledge sharing and learn which objects have been effective (and which have not been effective) in their collaborative...

  19. Mutagenesis of the lac promoter region in M13 mp10 phage DNA by 4'-hydroxymethyl-4,5',8-trimethylpsoralen

    International Nuclear Information System (INIS)

    Piette, J.; Decuyper-Debergh, D.; Gamper, H.

    1985-01-01

    Double-stranded M13 phage DNA (M13 mp10 replicative form) was photoreacted with 4'-hydroxymethyl-4,5',8-trimethylpsoralen, using light of wavelength greater than 320 nm or greater than 390 nm to generate predominantly crosslinks or monoadducts, respectively. The damaged DNAs were scored for inactivation and mutagenesis after transfection into Escherichia coli. The appearance of light-blue or colorless plaques on indicator medium showed that mutation had occurred in the lac insert of the viral DNA. A comparison of the consequences of the two phototreatments with psoralen supports the idea that crosslinks are both more lethal and more mutagenic than monoadducts. Numerous mutant clones partially or totally deficient in beta-galactosidase were plaque-purified and amplified. The viral DNA of each clone was sequenced by the dideoxy chain-terminating procedure. All of the observed base-pair changes were mapped to the lac promoter region and consisted of 3 transition, 14 transversion, and 6 single base-pair frame-shift mutations. The predominant mutation was a T.A----G.C transversion

  20. L'habitat à une échelle globale : importance respective de l'immigration et de l'extinction pour les peuplements de poissons des petits lacs

    Directory of Open Access Journals (Sweden)

    TONN W. M.

    1995-04-01

    Full Text Available Les deux processus qui déterminent la structure des communautés dans les habitats insulaires sont l'immigration d'espèces vers une communauté et l'extinction de celles qui étaient présentes auparavant. Bien que l'immigration et l'extinction se produisent généralement à des échelles supérieures à celles qu'il est possible d'étudier avec des expériences plannifiées, les écologistes peuvent améliorer leur compréhension de ces processus par l'analyse des distributions observées ; l'isolation, le caractère discret et la réplication des systèmes insulaires présentent des avantages pour réaliser de telles analyses. Comme pour les communautés observées sur de vraies îles, la structure des peuplements de poissons dans les petits lacs forestiers est le résultat de l'immigration et de l'extinction. L'importance relative de ces processus peut dépendre des caractéristiques d'habitat des lacs et des espèces présentes, ainsi que du cadre régional et historique des lacs étudiés. Dans une région donnée, la composition des peuplements locaux de poissons peut être reliée à un ensemble particulier de conditions d'habitat et, dans la mesure où ces facteurs peuvent être liés à l'immigration et à l'extinction, il devrait être possible d'analyser les relations peuplement-environnement pour en déduire l'importance relative de ces processus dans la formation de peuplements locaux dans et entre les régions et les continents. Nous avons réalisé des analyses à large échelle des relations peuplement-environnement des petits lacs forestiers de quatre régions tempérées d'Europe et d'Amérique du Nord ; l'utilisation d'une série d'analyses canonique partielle des correspondances nous a permis de distinguer la variation due aux relations peuplements-environnement d'un ensemble de facteurs associés à l'immigration contre l'extinction. Les isolations passées et présentes varient selon les lacs et les régions, comme la

  1. Croissance et alimentation des larves de corégones (Coregonus lavaretus dans le lac d'Annecy de mars à avril 1996

    Directory of Open Access Journals (Sweden)

    CRETENOY L.

    1997-04-01

    Full Text Available La capture de plus de 400 larves de Coregonus lavaretus à 7 dates différentes dans le lac d'Annecy de mars à avril 1996 a permis d'étudier conjointement leur croissance et l'évolution de leur régime alimentaire. Les larves capturées ont une taille comprise entre 8,5 et 20 mm et un stade larvaire allant de 0 à 4, ces deux paramètres étant fortement liés. À mesure qu'elles grandissent, les larves qui consomment d'abord préférentiellement les stades larvaires des copépodes, puis leurs stades adultes, se nourrissent ensuite majoritairement de cladocères. La comparaison des structures de taille des proies ingérées et du zooplancton présent dans le lac conduit à évoquer la notion d'expérience acquise par les larves pour expliquer cette dérive alimentaire.

  2. [Testicular testosterone production in male mice of inbred strains PT and CBA/Lac after a long-term period of stable social hierarchy].

    Science.gov (United States)

    Osadchuk, L V; Gutorova, N V; Kleshchev, M A

    2014-04-01

    Social dominance can alter testicular testosterone production, although there is pronounced variability in the relationship between social status and pattern of the testosterone response. The study designed to investigate how a long-term period of stable social hierarchy effects on testicular testosterone production in male mice of inbred strains PT and CBA/Lac. Paired males of different genotypes were housed together for 32 days beginning 38 day of age. Dyadic interactions of males generated dominance-subordination relationships during the first day after a social group has been produced and the social rank of each opponent was assessed by asymmetry in agonistic behaviour. Serum level of testosterone and its testicular content were evaluated in male mice of both inbred strains at 70 day of age after pair housing. Control animals were age- and genotype-matched single males that were housed in conventional cages. After a long-term period of pair housing, the serum testosterone level and its testicular content in males of both PT and CBA/Lac strains were not significantly different from the control. There were no significant differences in androgenic parameters between social ranks in male mice of both strains. The results indicate that in laboratory mice the pattern of testicular testosterone response to social hierarchy determined by a social situation, for example, a stability of social interactions, when the importance of aggressive competition for rank is minimal.

  3. Influence of the salting time on volatile compounds during the manufacture of dry-cured pork shoulder "lacón".

    Science.gov (United States)

    Purriños, Laura; Franco, Daniel; Carballo, Javier; Lorenzo, José M

    2012-12-01

    The effect of the length of salting time on volatile compounds throughout the manufacture of dry-cured "lacón" was studied using a purge-and-trap extraction and GC/MS analysis. For this study, six treatments of "lacón" were salted with different amounts of salt (LS (3 days of salting), MS (4 days of salting) and HS (5 days of salting)). The total area of volatile compounds increased significantly (Psalting time increased. Significant differences were found for the total area of all aldehydes for each salting time at the end of process. Hexanal presented the most relative abundance, showing highest content in HS treatments while LS treatments showed the lowest one at the end of salting, post-salting and drying-ripening stage. The influence of salting time on the content of 3-Octen-2-one was significant on salting stage (Psalting time affected (Psalting and at the end of drying-ripening stage. The salting time affected significantly (Psalt level (P>0.05) was detected on total hydrocarbons and total furans at the end of process. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Different effects of two newly-isolated probiotic Lactobacillus plantarum 15HN and Lactococcus lactis subsp. Lactis 44Lac strains from traditional dairy products on cancer cell lines.

    Science.gov (United States)

    Haghshenas, Babak; Abdullah, Norhafizah; Nami, Yousef; Radiah, Dayang; Rosli, Rozita; Khosroushahi, Ahmad Yari

    2014-12-01

    Lactobacillus and Lactococcus strains isolated from food products can be introduced as probiotics because of their health-promoting characteristics and non-pathogenic nature. This study aims to perform the isolation, molecular identification, and probiotic characterization of Lactobacillus and Lactococcus strains from traditional Iranian dairy products. Primary probiotic assessments indicated high tolerance to low pH and high bile salt conditions, high anti-pathogenic activities, and susceptibility to high consumption antibiotics, thus proving that both strains possess probiotic potential. Cytotoxicity assessments were used to analyze the effects of the secreted metabolite on different cancer cell lines, including HT29, AGS, MCF-7, and HeLa, as well as a normal human cell line (HUVEC). Results showed acceptable cytotoxic properties for secreted metabolites (40 μg/ml dry weight) of Lactococcus lactis subsp. Lactis 44Lac. Such performance was similar to that of Taxol against all of the treated cancer cell lines; however, the strain exhibited no toxicity on the normal cell line. Cytotoxic assessments through flow cytometry and fluorescent microscopy demonstrated that apoptosis is the main cytotoxic mechanism for secreted metabolites of L. lactis subsp. Lactis 44Lac. By contrast, the effects of protease-treated metabolites on the AGS cell line verified the protein nature of anti-cancer metabolites. However, precise characterizations and in vitro/in vivo investigations on purified proteins should be conducted before these metabolites are introduced as potential anti-cancer therapeutics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Chemical Compositions of RV Tauri Stars and Related Objects

    Science.gov (United States)

    Rao, S. S.; Giridhar, S.

    2014-04-01

    We have undertaken a comprehensive abundance analysis for a sample of relatively unexplored RV Tauri and RV Tauri like stars to further our understanding of post-Asymptotic Giant Branch (post-AGB) evolution. From our study based on high resolution spectra and a grid of model atmospheres, we find indications of mild s-processing for V820 Cen and IRAS 06165+3158. On the other hand, SU Gem and BT Lac exhibit the effects of mild dust-gas winnowing. We have also compiled the existing abundance data on RV Tauri objects and find that a large fraction of them are afflicted by dust-gas winnowing and aided by the present work, we find a small group of two RV Tauris showing mild s-process enhancement in our Galaxy. With two out of three reported s-process enhanced objects belonging to RV Tauri spectroscopic class C, these intrinsically metal-poor objects appear to be promising candidates to analyse the possible s-processing in RV Tauri stars.

  6. Seeing Objects as Faces Enhances Object Detection.

    Science.gov (United States)

    Takahashi, Kohske; Watanabe, Katsumi

    2015-10-01

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

  7. Seeing Objects as Faces Enhances Object Detection

    Directory of Open Access Journals (Sweden)

    Kohske Takahashi

    2015-09-01

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

  8. BROAD Lyα EMISSION FROM THREE NEARBY BL LACERTAE OBJECTS

    International Nuclear Information System (INIS)

    Stocke, John T.; Danforth, Charles W.; Perlman, Eric S.

    2011-01-01

    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 M sun ) as suggested by Guilbert et al. If these clouds are in pressure balance with a hotter (∼10 6 K) gas, the BLR contains too little mass to power the AGN by accretion alone.

  9. Objectivity And Moral Relativism

    OpenAIRE

    Magni, Sergio Filippo

    2017-01-01

    The relativity of morals has usually been taken as an argument against the objectivity of ethics. However, a more careful analysis can show that there are forms of moral objectivism which have relativistic implications, and that moral relativism can be compatible with the objectivity of ethics. Such an objectivity is not always in contrast to moral relativism and it is possible to be relativists without having to give up the claim of objectivity in ethics

  10. Objects in Motion

    Science.gov (United States)

    Damonte, Kathleen

    2004-01-01

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

  11. 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.

  12. Repurposing learning object components

    NARCIS (Netherlands)

    Verbert, K.; Jovanovic, J.; Gasevic, D.; Duval, E.; Meersman, R.

    2005-01-01

    This paper presents an ontology-based framework for repurposing learning object components. Unlike the usual practice where learning object components are assembled manually, the proposed framework enables on-the-fly access and repurposing of learning object components. The framework supports two

  13. 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....

  14. Manoomin: place-based research with Native American students on wild rice lakes on the Fond du Lac Band of Lake Superior Chippewa Reservation, northern Minnesota

    Science.gov (United States)

    Ito, E.; Myrbo, A.; Dalbotten, D. M.; Pellerin, H.; Greensky, L.; Howes, T.; Wold, A.; McEathron, M. A.; Shanker, V.

    2010-12-01

    The manoomin project is a collaboration between Fond du Lac Tribal and Community College (Cloquet, MN), the Reservation’s Resource Management Division, and the University of Minnesota funded by the NSF GEO-OEDG Program. It builds on a successful seven-year history of collaboration between these parties, including regular science camps (gidaakiimanaanimigawig, Our Earth Lodge) for students of a wide range of ages. We are working as a team with Native students to study the history of wild rice (manoomin; Zizania palustris), a culturally important resource, growing on Reservation lakes. The joint project takes two main approaches: study of sediment core samples collected from Reservation lakes; and the collection of traditional knowledge about wild rice from the Elders. Science campers collect lake cores during winter with the assistance of the U of MN’s LacCore (National Lacustrine Core Facility) and Resource Management and visit LacCore to log, split and describe cores soon thereafter. Academic mentors with a range of specialties (phytoliths, pollen, plant macrofossils, sedimentology, geochemistry, magnetics) spend 1-2 weeks during the summer with small groups of college-age (>18, many nontraditional) student interns working on a particular paleoenvironmental proxy from the sediment cores. Younger students (middle and high school) also work in small teams in half day units with the same mentors. All campers become comfortable in an academic setting, gain experience working in research labs learning and practicing techniques, and jointly interpret collective results. The continuation of the project over five years (2009-2014) will allow these students to develop relationships with scientists and to receive mentoring beyond the laboratory as they make transitions into 2- and 4-year colleges and into graduate school. Their research provides historical and environmental information that is relevant to their own land that will be used by Resource Management which is

  15. Investigation of radio objects with continuos optical spectra. The results of four-color electrophotometric observations

    International Nuclear Information System (INIS)

    Beskin, G.M.; Lyutyj, V.M.; Neizvestnyj, S.I.; Pustil'nik, S.I.; Shvartsman, V.F.

    1985-01-01

    The results of UBVR photometry of 30 radio objects with continuous optical spectra (ROCOSes) are reported. The observations were performed using five telescopes during the years 1979-1982; 54 values have been obtained of U, B, V magnitudes and 26 ones of R magnitude. Colours for 16 ROCOSes have been obtained for the first time. The analysis of the data results in the following conclusions. 1) Practically all colours of ROCOSes have proved to be in the region of localization of BL Lac objects' colours on UBV and BVR diagrams. This fact (altogether with the other data) indicates on the proximity of the objects of the two classes. 2) In half of all cases, instantaneous colours of ROCOSes corresponded to purely power-law optical continua F(ν) varies as νsup(α) with α approximately= -(1-2.5). 3) In the remaining cases, optical continua differed significantly from the power-law ones. 4) 6 ROCOSes appeared to be in the phases of deep minimum of brightness at the moment of observations (namely, about 3sup(m)-5sup(m) fainter than in the brightest phase known from the literature). The UBVR colours of none of them give indication on the presence of an elliptical galaxy which, according to conventional concepts, must encompass a variable nonthermal source. 5) Two blue objects, 0548+165 and 0713+199, which are situated at low galactic latitudes (b 2 =-5 deg and +14 deg respectively) have shown colours unusual for lacertids. Appendices contain the results of theoretical calculations of (U-B), (B-V) and (V-R) colours for purely power-law spectra F(ν)=constxνsup(α) with α in the range (-6.5-+2.5) and the results of UBV photometry of the BL Lac object OJ 287 during the years 1976-1982 (24 measurements)

  16. 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

  17. Digestibilidade e metabólitos sanguíneos de vacas da raça Holandesa superovuladas que receberam Lac100® ou linhaça em grão como fontes de gordura Digestibility and blood concentration of metabolites in superovulated dairy cows fed Lac100® or linseed as fat sources

    Directory of Open Access Journals (Sweden)

    F.L.B. Cavalieri

    2009-08-01

    Full Text Available Foram avaliados os efeitos de duas fontes de gordura, Lac100® (Yakult, fonte de ácido graxo ômega-6, e linhaça em grão (Linum usitatissimum (LIN, fonte de ácido graxo ômega-3, sobre a digestibilidade aparente da matéria seca (DMS, proteína bruta (DPB, fibra em detergente neutro (DFDN, fibra em detergente ácido (DFDA e extrato etéreo (DEE, e concentrações sanguíneas de HDL, LDL, VLDL, colesterol, triglicerídeos, glicose, cálcio, fósforo, N-ureico e progesterona. Foram utilizadas 10 vacas da raça Holandesa em lactação, distribuídas nos dois tratamentos, em um delineamento estatístico inteiramente casualizado. Os animais alimentados com Lac100® apresentaram maiores valores de DFDN (57,44% vs. 50,80% e DEE (77,70% vs. 72,18% quando comparados aos alimentados com LIN. Os animais alimentados com Lac100® apresentaram maiores concentrações de LDL (111,00 vs. 45,46mg/dL, HDL (82,27 vs. 64,93mg/dL e colesterol total (203,60 vs. 116,13mg/dL e menor concentração de N-ureico (13,22 vs. 15,19mg/dL em relação aos animais alimentados com linhaça em grão. As concentrações sanguíneas de glicose, cálcio, fósforo e progesterona não foram alteradas. Os resultados sugerem que a fonte de gordura na dieta modifica a DFDN e a DEE e, as concentrações sanguíneas de LDL, HDL e colesterol total em vacas em lactação.The effect of two sources of fat, calcium salts of soybean oil, Lac100® (Yakult, a source of omega-6 fatty acids or whole flaxseed (Linum usitatissiumum, a source of omega-3 fatty acids were evaluated to determine the apparent digestibility of dry matter (DDM, crude protein (DCP, neutral detergent fiber (DNDF, acid detergent fiber (DADF, and ether extract (DEE; and blood concentrations of HDL, LDL, VLDL, cholesterol, triglycerides, glucose, calcium, phosphorus, N-urea, and progesterone. Ten lactating Holstein cows were allocated in two treatments and a completely randomized design was used. Cows fed Lac100® had higher

  18. 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.

  19. 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...... system, knowledge about its own embodiment as well as knowledge about geometric relationships such as rigid body motion. This prior knowledge allows the extraction of representations that are semantically richer compared to many other approaches....

  20. Herbig-Haro objects

    International Nuclear Information System (INIS)

    Schwartz, R.D.

    1983-01-01

    Progress in the understanding of Herbig-Haro (HH) objects is reviewed. The results of optical studies of the proper motions and alignments, variability, and polarization of HH objects and the results of spectroscopic studies are discussed. Ground-based infrared studies and far-infrared observations are reviewed. Findings on the properties of molecular clouds associated with HH objects, on gas flows associated with HH IR stars, on maser emission, and on radio continuum observations are considered. A history of proposed excitation mechanisms for HH objects is briefly presented, and the salient shock-wave calculations aimed at synthesizing the spectra of HH objects are summarized along with hypotheses that have been advanced about the origin of the objects. 141 references

  1. Propelling Extended Objects

    Science.gov (United States)

    Humbert, Richard

    2010-01-01

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

  2. Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9

    Energy Technology Data Exchange (ETDEWEB)

    Siddique, Y.H.; Anjum, S.; Rahul x, Smita Jyoti

    2017-07-01

    Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05). The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05).

  3. Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ Bg9

    Directory of Open Access Journals (Sweden)

    YASIR HASAN SIDDIQUE

    2017-07-01

    Full Text Available Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05. The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05.

  4. Two new species of Hypostomus Lacépède (Teleostei: Loricariidae from the upper rio Paraná basin, Central Brazil

    Directory of Open Access Journals (Sweden)

    Cláudio H. Zawadzki

    Full Text Available Two new species of Hypostomus Lacépède (Teleostei: Loricariidae from the rio Paranaíba and rio Grande basins, both in the upper rio Paraná basin, central Brazil, are described herein. One of them is distinguished from all congeners, except H. albopunctatus, by having the pectoral-fin spine length equal to or smaller than the pelvic-fin spine. From H. albopunctatus, it is distinguished by having round dark spots (vs. pale on body and fins. The second species is distinguished from all congeners, except H. multidens and H. ternetzi, by having more than 115 teeth (vs. less than 109 per ramus on dentary and premaxilla. It is distinguished most readily from H. ternetzi by having teeth with two symmetrical (vs. asymmetrical cusps. It is distinguished from H. multidens by having round dark spots (vs. pale over body and fins.

  5. A new dark-dotted species of Hypostomus Lacépède (Siluriformes: Loricariidae from rio Paraguaçu, Bahia State, Brazil

    Directory of Open Access Journals (Sweden)

    Angela M. Zanata

    Full Text Available A new species of Hypostomus Lacépède is described from the rio Paraguaçu basin, Bahia State, Brazil. The new species is distinguished from its congeners by having black and conspicuous dots on a pale background, which are similar in size on the head, trunk, and fins, along with ventral surface of head and abdomen naked or the latter plated exclusively on its anterior portion, absence of ridges on head and trunk, and caudal-fin lobes relatively similar in length. The new species further differs from the sympatric H. chrysostiktos by having seven branched dorsal-fin rays instead of 10-11 and represents the eleventh siluriform species endemic to the rio Paraguaçu basin.

  6. Ultrasound-assisted synthesis of 2,4-thiazolidinedione and rhodanine derivatives catalyzed by task-specific ionic liquid: [TMG][Lac].

    Science.gov (United States)

    Suresh; Sandhu, Jagir Singh

    2013-03-03

    Synthesized arylidene derivatives of rhodanine and 2,4-thiazolidiendione have potent pharmacological activities, and these are also key substrates for the preparation of clinically used antidiabetics. Some 1,1,3,3-tetramethylguanidine-based task-specific ionic liquids (TSILs) 1a-1e were prepared and employed to the catalyzed solvent-free Knoevenagel condensation of 2,4-thiazolidinedione 3a and rhodanine 3b with a variety of aldehydes. Best results were obtained with 1,1,3,3-tetramethylguanidine lactate ([TMG][Lac]) 1c. The TSIL used can be easily recovered and recycled, yielding products 4-5 in excellent yields under ultrasonic environment without the formation of any side products or toxic waste.

  7. Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9

    International Nuclear Information System (INIS)

    Siddique, Y.H.; Anjum, S.; Rahul x, Smita Jyoti

    2017-01-01

    Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05). The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05).

  8. A study of uranium series disequilibrium in core profiles and mineral separates from the samples of Lac du Bonnet granite from the URL site, Pinawa, Manitoba, Canada

    International Nuclear Information System (INIS)

    Ivanovich, M.; Longworth, G.; Wilkins, M.A.; Hasler, S.E.

    1987-12-01

    Uranium series disequilibrium measurements of actinide activities and activity ratios have been used to study the geochemical history of Lac du Bonnet granite, from the URL site, Pinawa, Canada. Measurements on core profiles between fractured surfaces and the parent rock show that the granite underwent high temperature events several million years ago, followed by more recent low temperature events within the last million years. The main locations for the rock/water interaction and exchange of actinides are the fracture surfaces. The results of similar measurements on separated mineral phases show that the 'soft' minerals such as biotite and feldspar are more vulnerable to weathering than the 'hard' accessory minerals such as zircon. (author)

  9. 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

  10. Abstract Objects of Verbs

    DEFF Research Database (Denmark)

    2014-01-01

    Verbs do often take arguments of quite different types. In an orthodox type-theoretic framework this results in an extreme polysemy of many verbs. In this article, it is shown that this unwanted consequence can be avoided when a theory of "abstract objects" is adopted according to which...... these objects represent non-objectual entities in contexts from which they are excluded by type restrictions. Thus these objects are "abstract'' in a functional rather than in an ontological sense: they function as representatives of other entities but they are otherwise quite normal objects. Three examples...

  11. Effect of Ku80 deficiency on mutation frequencies and spectra at a LacZ reporter locus in mouse tissues and cells.

    Directory of Open Access Journals (Sweden)

    Rita A Busuttil

    Full Text Available Non-homologous end joining (NHEJ is thought to be an important mechanism for preventing the adverse effects of DNA double strand breaks (DSBs and its absence has been associated with premature aging. To investigate the effect of inactivated NHEJ on spontaneous mutation frequencies and spectra in vivo and in cultured cells, we crossed a Ku80-deficient mouse with mice harboring a lacZ-plasmid-based mutation reporter. We analyzed various organs and tissues, as well as cultured embryonic fibroblasts, for mutations at the lacZ locus. When comparing mutant with wild-type mice, we observed a significantly higher number of genome rearrangements in liver and spleen and a significantly lower number of point mutations in liver and brain. The reduced point mutation frequency was not due to a decrease in small deletion mutations thought to be a hallmark of NHEJ, but could be a consequence of increased cellular responses to unrepaired DSBs. Indeed, we found a substantial increase in persistent 53BP1 and gammaH2AX DNA damage foci in Ku80-/- as compared to wild-type liver. Treatment of cultured Ku80-deficient or wild-type embryonic fibroblasts, either proliferating or quiescent, with hydrogen peroxide or bleomycin showed no differences in the number or type of induced genome rearrangements. However, after such treatment, Ku80-deficient cells did show an increased number of persistent DNA damage foci. These results indicate that Ku80-dependent repair of DNA damage is predominantly error-free with the effect of alternative more error-prone pathways creating genome rearrangements only detectable after extended periods of time, i.e., in young adult animals. The observed premature aging likely results from a combination of increased cellular senescence and an increased load of stable, genome rearrangements.

  12. 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...... are covered from the point of view of program analysis, program transformation, computational complexity, etc....

  13. Exhibiting Epistemic Objects

    DEFF Research Database (Denmark)

    Tybjerg, Karin

    2017-01-01

    of exhibiting epistemic objects that utilize their knowledge-generating potential and allow them to continue to stimulate curiosity and generate knowledge in the exhibition. The epistemic potential of the objects can then be made to work together with the function of the exhibition as a knowledge-generating set...

  14. Object permanence in lemurs.

    Science.gov (United States)

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

    2009-03-01

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

  15. Investigating Music Information Objects

    Science.gov (United States)

    Weissenberger, Lynnsey K.

    2016-01-01

    This dissertation, titled "Investigating Music Information Objects," is a study of the nature, description, representations, and ideas related to music information objects (MIOs). This research study investigates how music practitioners from various traditions describe and conceptualize MIOs, using a theoretical framework to classify…

  16. Gamifying Video Object Segmentation.

    Science.gov (United States)

    Spampinato, Concetto; Palazzo, Simone; Giordano, Daniela

    2017-10-01

    Video object segmentation can be considered as one of the most challenging computer vision problems. Indeed, so far, no existing solution is able to effectively deal with the peculiarities of real-world videos, especially in cases of articulated motion and object occlusions; limitations that appear more evident when we compare the performance of automated methods with the human one. However, manually segmenting objects in videos is largely impractical as it requires a lot of time and concentration. To address this problem, in this paper we propose an interactive video object segmentation method, which exploits, on one hand, the capability of humans to identify correctly objects in visual scenes, and on the other hand, the collective human brainpower to solve challenging and large-scale tasks. In particular, our method relies on a game with a purpose to collect human inputs on object locations, followed by an accurate segmentation phase achieved by optimizing an energy function encoding spatial and temporal constraints between object regions as well as human-provided location priors. Performance analysis carried out on complex video benchmarks, and exploiting data provided by over 60 users, demonstrated that our method shows a better trade-off between annotation times and segmentation accuracy than interactive video annotation and automated video object segmentation approaches.

  17. Objects of Desire.

    Science.gov (United States)

    Zielinski, Dave

    2000-01-01

    Describes learning objects, also known as granules, chunks, or information nuggets, and likens them to help screens. Discusses concerns about how they can go wrong: (1) faulty pretest questions; (2) missing links in the learning object chain; (3) poor frames of reference; and (4) lack of customization. (JOW)

  18. Per Object statistical analysis

    DEFF Research Database (Denmark)

    2008-01-01

    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...

  19. 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...

  20. Stability of multihypernuclear objects

    International Nuclear Information System (INIS)

    Ikram, M.; Rather, Asloob A.; Usmani, A.A.; Patra, S.K.

    2016-01-01

    In present work, we analyze the stability of multi-hypernuclear objects having higher content of strangeness. The aim of this work is to test the stability of such objects which might be produced in heavy-ion reactions. Studies of such type of systems might have great implication to nuclear-astrophysics

  1. 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...

  2. Piles of objects

    KAUST Repository

    Hsu, Shu-Wei; Keyser, John

    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

  3. Object oriented programming

    International Nuclear Information System (INIS)

    Kunz, P.F.

    1990-01-01

    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

  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. 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...

  6. Abstract Objects of Verbs

    DEFF Research Database (Denmark)

    Robering, Klaus

    2014-01-01

    Verbs do often take arguments of quite different types. In an orthodox type-theoretic framework this results in an extreme polysemy of many verbs. In this article, it is shown that this unwanted consequence can be avoided when a theory of "abstract objects" is adopted according to which these obj......Verbs do often take arguments of quite different types. In an orthodox type-theoretic framework this results in an extreme polysemy of many verbs. In this article, it is shown that this unwanted consequence can be avoided when a theory of "abstract objects" is adopted according to which...... these objects represent non-objectual entities in contexts from which they are excluded by type restrictions. Thus these objects are "abstract'' in a functional rather than in an ontological sense: they function as representatives of other entities but they are otherwise quite normal objects. Three examples...

  7. The X-Ray Core of the Low-Luminosity Radio Galaxy 3C346 and ASCA Spectroscopy to Test BL LAC/Radio Galaxy Unification

    Science.gov (United States)

    Worrall, Diana

    2000-01-01

    the radio jets are seen at an angle to the line of sight of about 30 deg, intermediate between the radio-galaxy and quasar classes. The relatively hard ASCA response has allowed us to place an upper limit of 5.6 x 10(exp 43) ergs/ s on the 2-10 keV luminosity of any central X-ray component absorbed bN, gas which might be obscuring the broad-line emission region. Attached to this report is an almost final draft of a paper which we have prepared for submission to the Astrophysical Journal. Our combined ASCA and ROSAT results for NGC 6251 rule out our previously preferred flat-spectrum model and inverse-Compton interpretation for the source based on ROSAT data alone, but a softer X-ray spectrum and moderate absorption bring all the available data (including our early VLA HI measurements) into consistency, and we are reasonably confident that we understand the processes responsible for the X-ray emission. We have made some more sensitive HI absorption measurements which are currently being analyzed, and our plans are to publish our ASCA analysis in conjunction with the new HI results. The ASCA data for NGC 4261 have been difficult to interpret. A re-analysis of our ROSAT data with a wider range of physical parameters brings the ROSAT and ASCA results into reasonable agreement only if the emission from hot gas dominates more than suggested by our earlier work, which is itself unexpected since the radio core is bright and a large jet-related X-ray component would bring the source into agreement with results for others of its type. However, we have recently received our Chandra A01 data for this source, with the spatial resolution which allows us to separate thermal and non-thermal emission components. Our ASCA results will be re-interpreted once the analysis of our Chandra data is complete. The interpretation of the ASCA data for BL Lac object 3C 371 is ongoing, in conjunction with analysis of archival multifrequency data. Radio galaxies are complex in their X

  8. Nuclear Energy General Objectives

    International Nuclear Information System (INIS)

    2011-01-01

    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

  9. 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...

  10. 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.

  11. 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...

  12. Registration of Space Objects

    Science.gov (United States)

    Schmidt-Tedd, Bernhard

    2017-07-01

    Space objects are subject to registration in order to allocate "jurisdiction and control" over those objects in the sovereign-free environment of outer space. This approach is similar to the registration of ships in view of the high sea and for aircrafts with respect to the international airspace. Registration is one of the basic principles of space law, starting with UN General Assembly Resolution 1721 B (XVI) of December 20, 1961, followed by Resolution 1962 (XVIII) of December 13, 1963, then formulated in Article VIII of the Outer Space Treaty of 1967 and as specified in the Registration Convention of 1975. Registration of space objects can be seen today as a principle of customary international law, relevant for each spacefaring state. Registration is divided into a national and an international level. The State Party establishes a national registry for its space objects, and those registrations have to be communicated via diplomatic channel to the UN Register of space objects. This UN Register is handled by the UN Office for Outer Space Affairs (UNOOSA) and is an open source of information for space objects worldwide. Registration is linked to the so-called launching state of the relevant space object. There might be more than one launching state for the specific launch event, but only one state actor can register a specific space object. The state of registry gains "jurisdiction and control" over the space object and therefore no double registration is permissible. Based on the established UN Space Law, registration practice was subject to some adaptions due to technical developments and legal challenges. After the privatization of the major international satellite organizations, a number of non-registrations had to be faced. The state actors reacted with the UN Registration Practice Resolution of 2007 as elaborated in the Legal Subcommittee of UNCOPUOS, the Committee for the Peaceful Use of Outer Space. In this context an UNOOSA Registration Information

  13. 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....

  14. CODAS object monitoring service

    International Nuclear Information System (INIS)

    Wheatley, M.R.; Rainford, M.

    2001-01-01

    The primary Control and Data Acquisition System (CODAS) of JET is based on a TCP/IP network of more than 150 computers. The CODAS computers provide the JET machine control and data acquisition for over 70,000 digital and analog signals. The Object Monitoring Service (OMS) is used by applications for monitoring objects for presentation to the JET machine operators and for the operation of individual software components (such as valve state, access control, mimic definition changes and internal data distribution). Each server typically handles connections from around 60 clients monitoring upwards of 2000 objects. Some servers have over 150 clients and 5000 objects. Acquisition libraries are dynamically linked into a running server as required either to acquire data values for objects or to forward requests to other OMS servers. A mechanism involving dynamic linking allows new libraries to be integrated without stopping or changing running software. OMS provides a very reliable and highly successful 'data-type independent' means of monitoring many different objects. It allows applications to take advantage of new data sources, without the need to change existing code

  15. Nuclear Fuel Cycle Objectives

    International Nuclear Information System (INIS)

    2013-01-01

    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 this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the 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 written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and 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 government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards 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 considered and the specific goals to be achieved at different stages of implementation, all of which are consistent with the Basic Principles

  16. REPEUPLEMENTS EN ALEVINS NOURRIS ET DÉMOGRAPHIE DE LA POPULATION DE TRUITE (SALMO TRUTTA L. DANS LE REDON, UN AFFLUENT DU LAC LÉMAN INTERROMPU PAR UN OBSTACLE

    Directory of Open Access Journals (Sweden)

    CHAMPIGNEULLE A.

    2003-01-01

    Full Text Available La démographie d’une population de truite (Salmo trutta L. a été étudiée, dans un contexte de repeuplements en alevins nourris, sur le Redon, un affluent du lac Léman. On trouve sur le Redon une situation typique de nombreux affluents du Léman : une zone aval ouverte sur le lac mais rapidement interrompue par un obstacle empêchant la remontée des truites de lac. Des relâchers d’alevins nourris issus d’œufs de géniteurs sauvages de truite de lac ou de géniteurs domestiques, pratiqués en fin de printemps-début été à des densités de 40-60 ind./100 m2, fournissent un recrutement additionnel important pouvant constituer la part dominante du peuplement automnal en 0 +, puis 1 +. Sur les zones ouvertes à la pêche, colonisées ou non par la truite de lac, la densité de la population automnale en place s’effondre entre le stade 1 + et les stades > 1 +. Les résultats comparatifs entre zones ouvertes ou fermées à la pêche indiquent que la pêche peut être un facteur de mortalité important. La dynamique comparée des truites d’origine lacustre ou sédentaire suggère l’existence d’un taux de sédentarisation plus faible pour les 1 + issus de truites de lac comparativement aux 1 + issus de la fraie de truites sédentaires en zone de réserve. Une expérimentation suggère l’existence de mouvements de dévalaison ayant lieu avant octobre et touchant préférentiellement les 0 + d’origine lacustre ayant eu la croissance initiale la plus forte. L’étude montre que : - des alevins nourris d’origine lacustre ou domestique, relâchés en fin de printemps-début été, fournissent des géniteurs de truite de lac remontant dans la rivière de relâcher, avec cependant une proportion moindre (4 fois dans le cas de l’origine domestique comparativement à l’origine lacustre. Malgré leur forte contribution aux stades de juvéniles 0 + et 1 +, les alevins domestiques de pisciculture contribuent peu aux retours de g

  17. 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.

  18. Radioactive Waste Management Objectives

    International Nuclear Information System (INIS)

    2011-01-01

    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

  19. TESS Objects of Interest

    Science.gov (United States)

    Guerrero, Natalia; Glidden, Ana; Fausnaugh, Michael; TESS Team

    2018-01-01

    We describe the search for TESS Objects of Interest (TOIs), led by the MIT branch of the TESS Science Office (TSO). TSO has developed a tool called TESS Exoplanet Vetter (TEV) to facilitate this process. Individuals independently examine data validation products for each target and assign a category to the object: planet candidate, eclipsing binary, other astrophysical, stellar variability, or instrument noise/systematic. TEV assigns a preliminary follow-up priority designation to each object and allows for modification when final dispositions are decided on in a group setting. When all targets are vetted, TEV exports a catalogue of TOIs which is delivered to the TESS Follow-Up Observing Program (TFOP), working with ExoFOP-TESS, and made publicly available on the official TESS website and the Mikulski Archive for Space Telescopes (MAST).

  20. [Medicine and conscientious objection].

    Science.gov (United States)

    Martínez, K

    2007-01-01

    Conscientious objection to democratically accepted laws in democratic societies is a fact, both among citizens and among professionals. Due respect for laws is a prima facie duty in these societies. But democratic justice must at the same time respect peoples' conscience for it constitutes the ethical identity of individuals. And both law and ethics are necessary - although neither of them is sufficient - for its realization. The problem of conscientious objection among healthcare professionals is analysed from this standpoint and the conclusion is that objection is not an absolute right to exemption from several duties, but that the responsibility of the professional and of the institutions towards the citizenry must always be taken into account. Some solutions are suggested that try to protect both the professionals and the citizens in a bi-directional way.

  1. Media, journalism, objectivity

    Directory of Open Access Journals (Sweden)

    Vlajki Emil

    2013-01-01

    Full Text Available This is the text around the themes: Media and Journalism, are confronted two directions of opinions: humanism and elitism. Humanism believes that media and journalism must be metaphysically objective: able to tell the truth regardless of time, place and terms of events. Another approach, elitism, is connected with Hegel's philosophy of history. Hegel's conceptual apparatus includes: Idea, History dialectic, 'cunning mind,' self- development and self-realization. In this context, media and journalism are considered as organic unity, an inseparable part of some dialectical totality. More specifically media and journalism can be objective only if they defend concrete ideological assumptions of society to which they belong. Any other understanding of these two concepts is non-objective, mere moralizing and / or demagoguery.

  2. 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.

  3. Object-oriented communications

    International Nuclear Information System (INIS)

    Chapman, L.J.

    1989-01-01

    OOC is a high-level communications protocol based on the object-oriented paradigm. OOC's syntax, semantics, and pragmatics balance simplicity and expressivity for controls environments. While natural languages are too complex, computer protocols are often insufficiently expressive. An object-oriented communications philosophy provides a base for building the necessary high-level communications primitives like I don't understand and the current value of X is K. OOC is sufficiently flexible to express data acquisition, control requests, alarm messages, and error messages in a straightforward generic way. It can be used in networks, for inter-task communication, and even for intra-task communication

  4. Quantum objective realism

    International Nuclear Information System (INIS)

    Bednorz, Adam

    2015-01-01

    The question of whether quantum measurements reflect some underlying objective reality has no generally accepted answer. We show that a description of such reality is possible under natural conditions such as linearity and causality, although in terms of moments and cumulants of finite order and without relativistic invariance. The proposed construction of observations’ probability distribution originates from weak, noninvasive measurements, with detection error replaced by some external finite noise. The noise allows us to construct microscopic objective reality, but remains dynamically decoupled and hence unobservable at the macroscopic level. (paper)

  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. TP53 and lacZ mutagenesis induced by 3-nitrobenzanthrone in Xpa-deficient human TP53 knock-in mouse embryo fibroblasts.

    Science.gov (United States)

    Kucab, Jill E; Zwart, Edwin P; van Steeg, Harry; Luijten, Mirjam; Schmeiser, Heinz H; Phillips, David H; Arlt, Volker M

    2016-03-01

    3-Nitrobenzanthrone (3-NBA) is a highly mutagenic compound and possible human carcinogen found in diesel exhaust. 3-NBA forms bulky DNA adducts following metabolic activation and induces predominantly G:CT:A transversions in a variety of experimental systems. Here we investigated the influence of nucleotide excision repair (NER) on 3-NBA-induced mutagenesis of the human tumour suppressor gene TP53 and the reporter gene lacZ. To this end we utilised Xpa -knockout (Xpa-Null) human TP53 knock-in (Hupki) embryo fibroblasts (HUFs). As Xpa is essential for NER of bulky DNA adducts, we hypothesized that DNA adducts induced by 3-NBA would persist in the genomes of Xpa-Null cells and lead to an increased frequency of mutation. The HUF immortalisation assay was used to select for cells harbouring TP53 mutations following mutagen exposure. We found that Xpa-Null Hupki mice and HUFs were more sensitive to 3-NBA treatment than their wild-type (Xpa-WT) counterparts. However, following 3-NBA treatment and immortalisation, a similar frequency of TP53-mutant clones arose from Xpa-WT and Xpa-Null HUF cultures. In cells from both Xpa genotypes G:CT:A transversion was the predominant TP53 mutation type and mutations exhibited bias towards the non-transcribed strand. Thirty-two percent of 3-NBA-induced TP53 mutations occurred at CpG sites, all of which are hotspots for mutation in smokers' lung cancer (codons 157, 158, 175, 245, 248, 273, 282). We also examined 3-NBA-induced mutagenesis of an integrated lacZ reporter gene in HUFs, where we again observed a similar mutant frequency in Xpa-WT and Xpa-Null cells. Our findings suggest that 3-NBA-DNA adducts may evade removal by global genomic NER; the persistence of 3-NBA adducts in DNA may be an important factor in its mutagenicity. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Bilan des introductions de salmonidés dans les lacs et ruisseaux d'altitude des Hautes-Pyrénées

    Directory of Open Access Journals (Sweden)

    DELACOSTE M.

    1997-01-01

    Full Text Available Les introductions de Salmonidés ont été importantes au cours des 60 dernières années dans les lacs et ruisseaux d'altitude des Hautes-Pyrénées. Six espèces de Salmonidés ont été introduites dans des milieux qui, pour la plupart, étaient vierges de populations piscicoles : la truite commune (Salmo trutta L., la truite arc-en-ciel (Oncorhynchus mykiss Walbaum, l'omble de fontaine (Salvelinus fontinalis Mitchill, l'omble chevalier (Salvelinus alpinus L., le cristivomer (Salvelinus namaycush Walbaum et le splake (Salvelinus fontinalis x Salvelinus namaycush. Dans de très nombreux cas, ces introductions ont abouti à des acclimatations. En revanche, les naturalisations sont beaucoup plus rares. Seules les espèces lacustres (cristivomer et omble chevalier se sont naturalisées dans la majorité des lacs où elles ont été introduites. Les conditions de reproduction constituent le facteur clé permettant d'expliquer la naturalisation des espèces. En ruisseau, il faut y ajouter la compétition avec l'espèce indigène (la truite commune, la pression halieutique ainsi que les conditions hivernales très rigoureuses. Les incidences écologiques des introductions sur les populations de truites communes indigènes sont faibles. En revanche, elles ne sont pas négligeables pour les populations de batraciens. Cette politique d'introduction a largement participé au développement de l'halieutisme dans ces milieux d'altitude. En cela, les introductions ont parfaitement répondu aux objectifs halieutiques qu'on leur avait fixés. L'acquisition de connaissances sur l'ensemble de la chaîne pyrénéenne constitue aujourd'hui une étape incontournable pour une politique de gestion globale des introductions.

  8. Spatial and Temporal Variations in Diatoms from la Chaine des Lacs Urban Watershed, Nord-Pas France, in Relation to Water Quality

    Science.gov (United States)

    Noble, P. J.; Van de Vijver, B.; Verleyen, E.; Prygiel, J.; Ivanovsky, A.; Lesven, L.; Billon, G.

    2016-12-01

    Diatom analysis was conducted on lake sediments in la Chaîne des Lacs (CDL), a shallow eutrophic urban park and storm control system in Villeneuve d'Ascq, France, to address both the present day water quality, and the evolution of this urban system over its 40 year history. The main lake, Lac du Héron (LDH), received recent attention because of water quality problems, including eutrophication, harmful algal blooms, and invasion by the macrophyte Elodea in 2012. A total of 17 sites were collected in CDL, 11 of which were in LDH, to document spatial variability, and a 26cm long core addresses historical changes. The bulk of the diatom assemblage in LDH can be classified as both eutrophic and moderately metal tolerant, using modern national diatom indices developed and used by the French regional water agencies. Surface sediment samples within LDH show large spatial variations in %Cocconeis placentula whose habitat is epiphytic growth on Elodea. Other variation is reflected in the phytoplankton composition both spatially, and interannually. Aulacoseira muzzanensis and Cyclostephanos dubius showed greater abundance in the open water habitats in LDH, whereas sites in CDL outside of LDH had greater Cyclotella meneghiniana. Temporally, Stephanodicsus (largely S. hantzschii), the dominant diatom in early spring, were present in greater abundances in the 2016 surface sediment samples than in any of the 2015 samples. One possible explanation is that the 2016 samples, taken March 30th, preferentially preserved the early spring Stephanodiscus bloom, in contrast to the 2015 samples, which were taken in January. The sediment core provides an historical record, where the uppermost 4cm plot with the bulk of the LDH surface samples and contain abundant Cocconeis, 4 -14cm is phytoplankton-rich, largely Cyclostephanos dubius and Aulacoseira muzzanensis, and represents a less weed-choked environment prior to the 2012 Elodea invasion. The base of the core is dominated by Amphora and

  9. 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.

  10. Technical objectives of inspection

    International Nuclear Information System (INIS)

    Sorenson, R.J.; Stewart, K.B.; Schneider, R.A.

    1976-01-01

    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

  11. 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

  12. Boundary-Object Trimming

    DEFF Research Database (Denmark)

    Bossen, Claus; Jensen, Lotte Groth; Udsen, Flemming Witt

    2014-01-01

    implementation, which also coupled the work of medical secretaries more tightly to that of other staff, and led to task drift among professions. Medical secretaries have been relatively invisible to health informatics and CSCW, and we propose the term ‘boundary-object trimming’ to foreground and conceptualize...

  13. The Object of Research

    DEFF Research Database (Denmark)

    Bean, Jonathan; Figueiredo, Bernardo; Pico Larsen, Hanne

    2017-01-01

    The paper outlines a methodological approach for investigating how consumers create brand meaning using the material resources companies provide. The approach draws from Material Engagement Theory—to discuss the role of consumers in creating patterns of meaning by engaging with objects. It also e...

  14. Robust video object cosegmentation.

    Science.gov (United States)

    Wang, Wenguan; Shen, Jianbing; Li, Xuelong; Porikli, Fatih

    2015-10-01

    With ever-increasing volumes of video data, automatic extraction of salient object regions became even more significant for visual analytic solutions. This surge has also opened up opportunities for taking advantage of collective cues encapsulated in multiple videos in a cooperative manner. However, it also brings up major challenges, such as handling of drastic appearance, motion pattern, and pose variations, of foreground objects as well as indiscriminate backgrounds. Here, we present a cosegmentation framework to discover and segment out common object regions across multiple frames and multiple videos in a joint fashion. We incorporate three types of cues, i.e., intraframe saliency, interframe consistency, and across-video similarity into an energy optimization framework that does not make restrictive assumptions on foreground appearance and motion model, and does not require objects to be visible in all frames. We also introduce a spatio-temporal scale-invariant feature transform (SIFT) flow descriptor to integrate across-video correspondence from the conventional SIFT-flow into interframe motion flow from optical flow. This novel spatio-temporal SIFT flow generates reliable estimations of common foregrounds over the entire video data set. Experimental results show that our method outperforms the state-of-the-art on a new extensive data set (ViCoSeg).

  15. 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

  16. Suggestive Objects at Work

    DEFF Research Database (Denmark)

    Ratner, Helene Gad

    2009-01-01

    In Western secular societies, spiritual life is no longer limited to classical religious institutions but can also be found at workplace organizations. While spirituality is conventionally understood as a subjective and internal process, this paper proposes the concept of ‘suggestive objects......’, constructed by combining insights from Gabriel Tarde's sociology with Bruno Latour's actor-network theory, to theorize the material dimension of organizational spirituality. The sacred in organizations arises not from the internalization of collective values but through the establishment of material...... scaffolding. This has deep implications for our understanding of the sacred, including a better appreciation of the way that suggestive objects make the sacred durable, the way they organize it....

  17. 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...... and accepted. The European Space Agency mission Gaia is a proposed space observatory, designed to perform a highly accurate census of our galaxy, the Milky Way, and beyond. Through accurate measurement of star positions, Gaia is expected to discover thousands of extra-solar planets and follow the bending...... of starlight by the Sun, and therefore directly observe the structure of space-time. This thesis explores several aspects of the observation of NEOs with Gaia, emphasising detection of NEOs and the quality of orbits computed from Gaia observations. The main contribution is the work on motion detection...

  18. DOLIB: Distributed Object Library

    Energy Technology Data Exchange (ETDEWEB)

    D' Azevedo, E.F.

    1994-01-01

    This report describes the use and implementation of DOLIB (Distributed Object Library), a library of routines that emulates global or virtual shared memory on Intel multiprocessor systems. Access to a distributed global array is through explicit calls to gather and scatter. Advantages of using DOLIB include: dynamic allocation and freeing of huge (gigabyte) distributed arrays, both C and FORTRAN callable interfaces, and the ability to mix shared-memory and message-passing programming models for ease of use and optimal performance. DOLIB is independent of language and compiler extensions and requires no special operating system support. DOLIB also supports automatic caching of read-only data for high performance. The virtual shared memory support provided in DOLIB is well suited for implementing Lagrangian particle tracking techniques. We have also used DOLIB to create DONIO (Distributed Object Network I/O Library), which obtains over a 10-fold improvement in disk I/O performance on the Intel Paragon.

  19. DOLIB: Distributed Object Library

    Energy Technology Data Exchange (ETDEWEB)

    D`Azevedo, E.F.; Romine, C.H.

    1994-10-01

    This report describes the use and implementation of DOLIB (Distributed Object Library), a library of routines that emulates global or virtual shared memory on Intel multiprocessor systems. Access to a distributed global array is through explicit calls to gather and scatter. Advantages of using DOLIB include: dynamic allocation and freeing of huge (gigabyte) distributed arrays, both C and FORTRAN callable interfaces, and the ability to mix shared-memory and message-passing programming models for ease of use and optimal performance. DOLIB is independent of language and compiler extensions and requires no special operating system support. DOLIB also supports automatic caching of read-only data for high performance. The virtual shared memory support provided in DOLIB is well suited for implementing Lagrangian particle tracking techniques. We have also used DOLIB to create DONIO (Distributed Object Network I/O Library), which obtains over a 10-fold improvement in disk I/O performance on the Intel Paragon.

  20. A study of small-scale foliation in lengths of core enclosing fault zones in borehole WD-3, Permit Area D, Lac du Bonnet Batholith

    Energy Technology Data Exchange (ETDEWEB)

    Ejeckam, R. B.

    1992-12-01

    Small-scale foliation measurements in lengths of core from borehole WD-3 of Permit Area D of the Lac du Bonnet Batholith have defined five major mean orientation sets. They strike NW, N and NE. The orientations (strike to the left of the dip direction/dip) of these sets are as follows: Set I - 028/74 deg; II - 001/66 deg; III - 100/58 deg; IV - 076/83 deg; and V - 210/40 deg. The small-scale foliations were defined by different mineral types such as biotite crystals, plagioclase, mineral banding and quartz lenses. Well-developed biotite foliation is commonly present whenever well-developed plagioclase foliation exists, but as the strength of development weakens, the preferred orientations of plagioclase foliation do not correspond to those of biotite. It is also noted that the foliations appear to strike in directions orthogonal to the fractures in the fracture zones in the same depth interval. No significant change in foliation orientation was observed in Zones I to IV. Set V, however, whose mean orientation is 210/40 deg, is absent from the Zone IV interval, ranging from 872 to 905 m. (auth)

  1. Radio and γ -Ray Variability in the BL Lac PKS 0219−164: Detection of Quasi-periodic Oscillations in the Radio Light Curve

    Energy Technology Data Exchange (ETDEWEB)

    Bhatta, Gopal, E-mail: gopalbhatta716@gmail.com [Astronomical Observatory of the Jagiellonian University, ul. Orla 171, 30-244 Kraków (Poland); Mt. Suhora Observatory, Pedagogical University, ul. Podchorazych 2, 30-084 Kraków (Poland)

    2017-09-20

    In this work, we explore the long-term variability properties of the blazar PKS 0219−164 in the radio and the γ -ray regime, utilizing the OVRO 15 GHz and the Fermi /LAT observations from the period 2008–2017. We found that γ -ray emission is more variable than the radio emission implying that γ -ray emission possibly originated in more compact regions while the radio emission represented continuum emission from the large-scale jets. Also, in the γ -ray, the source exhibited spectral variability, characterized by the softer-when-brighter trend, a less frequently observed feature in the high-energy emission by BL Lacs. In radio, using Lomb–Scargle periodogram and weighted wavelet z -transform, we detected a strong signal of quasi-periodic oscillation (QPO) with a periodicity of 270 ± 26 days with possible harmonics of 550 ± 42 and 1150 ± 157 day periods. At a time when detections of QPOs in blazars are still under debate, the observed QPO with high statistical significance (∼97%–99% global significance over underlying red-noise processes) and persistent over nearly 10 oscillations could make one of the strongest cases for the detection of QPOs in blazar light curves. We discuss various blazar models that might lead to the γ -ray and radio variability, QPO, and the achromatic behavior seen in the high-energy emission from the source.

  2. Mutagenicity of the potent rat hepatocarcinogen 6BT to the liver of transgenic (lacI) rats: consideration of a reduced mutation assay protocol.

    Science.gov (United States)

    Lefevre, P A; Tinwell, H; Ashby, J

    1997-01-01

    6-(p-dimethylaminophenylazo)benzothiazole (6BT) is an unusually potent rat hepatocarcinogen, producing large malignant liver tumours after only 2-3 months of dietary administration in a riboflavin-deficient diet. This azocarcinogen has been evaluated in a Big Blue F344 transgenic rat (lacI) gene mutation assay. In a reproduction of the early stages of the carcinogenesis bioassay of this agent, rats were maintained on a riboflavin-deficient diet and were given 10 consecutive daily doses of 6BT (10 mg/kg) by oral gavage. The animals were killed and the livers examined 11 days after the final dose. The livers of 6BT-treated rats showed evidence of hepatocellular hypertrophy in centrolobular areas, with some indication of an increased incidence of mitotic figures. An approximately 10-fold increase in the mutation frequency of DNA isolated from an aliquot of the combined liver homogenates of 6BT-treated rats was observed over that obtained from an equivalent aliquot from control animals. Examination of DNA samples isolated from the livers of individual animals confirmed that 6BT was mutagenic in Big Blue rat livers. These data extend the sensitivity of this transgenic assay to include azo hepatocarcinogens. The determination of mutation frequencies using pooled tissue samples represented a major resource-saving adaptation of the assay protocol in the present study; the general advantages and disadvantages of this practice are discussed.

  3. Past and future fracturing in AECL Research areas in the superior province of the Canadian Precambrian Shield, with emphasis on the Lac du Bonnet Batholith

    Energy Technology Data Exchange (ETDEWEB)

    Brown, A; Everitt, R A; Martin, C D; Davison, C C [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

    1995-10-01

    The likelihood that future fracturing, arising from geologic causes, could occur in the vicinity of a nuclear fuel waste repository in plutonic rock of the Canadian Precambrian Shield, is examined. The report discusses the possible causes of fracturing (both past and future) in Shield rocks. The report then examines case histories of fracture formation in Precambrian plutonic rocks in AECL`s Research Areas, especially the history of the Lac du Bonnet Batholith, in the Whiteshell Area, Manitoba. Initially, fractures can be introduced into intrusive plutonic rocks during crystallization and cooling of an intrusive magma. These fractures are found at all size scales; as late residual magma dyking, hydraulic fracturing by retrograde boiling off of hydrothermal fluids, and, in some cases, through local differential cooling. Subsequent fracturing is largely caused by changes in environmental temperature and stress field, rather than by alteration of the material behaviour of the rock. Pluton emplacement during orogeny is commonly accompanied by uplift and erosional exhumation, altering both the tectonic and the lithostatic stresses, the rock temperature gradient and the pore fluid characteristics.

  4. Past and future fracturing in AECL Research areas in the superior province of the Canadian Precambrian Shield, with emphasis on the Lac du Bonnet Batholith

    International Nuclear Information System (INIS)

    Brown, A.; Everitt, R.A.; Martin, C.D.; Davison, C.C.

    1995-10-01

    The likelihood that future fracturing, arising from geologic causes, could occur in the vicinity of a nuclear fuel waste repository in plutonic rock of the Canadian Precambrian Shield, is examined. The report discusses the possible causes of fracturing (both past and future) in Shield rocks. The report then examines case histories of fracture formation in Precambrian plutonic rocks in AECL's Research Areas, especially the history of the Lac du Bonnet Batholith, in the Whiteshell Area, Manitoba. Initially, fractures can be introduced into intrusive plutonic rocks during crystallization and cooling of an intrusive magma. These fractures are found at all size scales; as late residual magma dyking, hydraulic fracturing by retrograde boiling off of hydrothermal fluids, and, in some cases, through local differential cooling. Subsequent fracturing is largely caused by changes in environmental temperature and stress field, rather than by alteration of the material behaviour of the rock. Pluton emplacement during orogeny is commonly accompanied by uplift and erosional exhumation, altering both the tectonic and the lithostatic stresses, the rock temperature gradient and the pore fluid characteristics

  5. Evaluation of the toxic potential of calcium carbide in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9).

    Science.gov (United States)

    Danish, Mohd; Fatima, Ambreen; Khanam, Saba; Jyoti, Smita; Rahul; Ali, Fahad; Naz, Falaq; Siddique, Yasir Hasan

    2015-11-01

    In the present study the toxic potential of calcium carbide (CaC2) was studied on the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9). The third instar larvae were exposed to 2, 4, 8, 16 and 32×10(-3)g/ml of CaC2 in diet for 24h. The results reveal that the dose 2×10(-3)g/ml was not toxic but the remaining doses showed a dose dependent significant increase in the hsp70 expression, β-galactosidase activity, tissue damage, oxidative stress markers (lipid peroxidation and protein carbonyl content), glutathione-S-transferase activity, expression of Caspase 3 and 9, apoptotic index and DNA damage (midgut cells). A significant reduction as compared to control group in total protein, glutathione content and acetylcholinesterase activity was also observed. The Inductively Coupled Plasma Atomic Emission Spectroscopy analysis (ICPAES) reveals the presence of copper, iron, sodium, aluminium, manganese, calcium, nickel and mercury. The toxic effects of CaC2 in the present study may be attributed to the impurities present in it. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A 400-year phytolith-based reconstruction of wild rice (Zizania palustris) abundance from Mud Lake core sediments, Fond du Lac Band of Lake Superior Chippewa Reservation, Minnesota, USA.

    Science.gov (United States)

    Munoz, R.; Caylor, E.; Yost, C. L.; Drake, C.; Ladwig, J. L.; Myrbo, A.; Howes, T.

    2014-12-01

    Wild rice (Zizania palustris L.) is an aquatic grass with spiritual and subsistence significance to Native people of the Great Lakes region of North America. Mud Lake (Mashkiigwaagamaag), located on the Fond du Lac Band of Lake Superior Chippewa Reservation in Carlton County, Minnesota, USA, once supported an extensive population of wild rice (manoomin). However, early 20th century attempts to ditch and drain surrounding wetlands for landuse intensification severely altered the natural hydrological system that supports wild rice. Fond du Lac Resource Management (FDLRM) technicians are currently working to increase the wild rice population in Mud Lake. As part of these efforts, this phytolith study was undertaken to better understand how wild rice abundance has fluctuated over the past 400 years, with particular emphasis on the 19th and 20th centuries. Phytoliths are microscopic opal silica plant remains that are incorporated into soils and lake sediments after the plant-parts that contain them decay. Wild rice produces phytolith morphotypes that are unequivocally diagnostic. Mud Lake core MNMN-MUD11-1C-1P-1 (46°43'38.39"N, 92°42'2.45"W) was piston cored by LacCore (National Lacustrine Core Facility) and FDLRM technicians on 24 May 2011. Initial core descriptions, multi-sensor core logging, phytolith sampling and phytolith extractions were completed during the summer of 2014 at LacCore. Wild rice phytolith identification and quantification was conducted on twelve samples using brightfield microscopy at 400x magnification. Wild rice phytolith concentration values ranged from 68 to 2,300 phytoliths/cm3. Wild rice accumulation rates ranged from 9 to 383 phytoliths/ cm2/yr, peaking in 1952 AD. Wild rice abundance in Mud Lake appears to be influenced by a complex set of variables that include anthropogenic disturbance, climatic events and aquatic plant community succession.

  7. Effect of eugenol on the mutagenicity of benzo[a]pyrene and the formation of benzo[a]pyrene-DNA adducts in the X-lacZ-transgenic mouse.

    NARCIS (Netherlands)

    Rompelberg, C.J.M.; Steenwinkel, M.J.S.T.; Asten, J.G. van; Delft, J.H.M. van; Baan, R.A.; Verhagen, H.

    1996-01-01

    To study the possible reduction by eugenol of the mutagenicity and genotoxicity of benzoja]pyrene (B[a]P) in vivo, the X-lacZ-transgenic mouse strain 40.6 (Muta(TM)Mouse) was used. Male mice were fed a diet containing 0.4% (w/w) eugenol or a control diet for 58 days. On day 10, half of the mice

  8. War Journalism and 'Objectivity'

    Directory of Open Access Journals (Sweden)

    Annabel McGoldrick

    2006-10-01

    Full Text Available This article opens by considering an apparent paradox. Many professional journalists, working on many media in many countries, consider themselves 'objective'. They do not, at least, set out to skew their coverage of important issues in favour of one side or the other. And yet much of their coverage of conflicts shows a discernible dominant pattern of War Journalism - biased in favour of war. This is not because of a lack of objectivity, the article suggests, but a surfeit. The set of conventions many editors and reporters regard as defining 'objective' journalism arose in response to economic and political conditions which rewarded news that could commend itself as unobjectionable to the maximum number of potential customers. Three of the most important conventions privilege official sources; a dualistic construction of stories and event, over process. Each of these, when applied to the representation of conflicts, leads readers and audiences - or leaves them - to over-value violent, reactive responses and under-value non-violent, developmental responses. Industry conventions sit uneasily alongside equally time-honoured expectations of journalism. These are encoded in rules and regulations governing the content of broadcast news, in many jurisdictions which have a public service concept for radio and television. In some respects, War Journalism can be shown to make it more difficult for broadcast news services to fulfil their public service obligations. Awareness is now growing, of the tension between these two pressures on journalism and its influence on the way pressing public debates are shaped and mediated. More Peace Journalism would help to bring public service news back into line with legitimate public expectations.

  9. Numerical Analysis Objects

    Science.gov (United States)

    Henderson, Michael

    1997-08-01

    The Numerical Analysis Objects project (NAO) is a project in the Mathematics Department of IBM's TJ Watson Research Center. While there are plenty of numerical tools available today, it is not an easy task to combine them into a custom application. NAO is directed at the dual problems of building applications from a set of tools, and creating those tools. There are several "reuse" projects, which focus on the problems of identifying and cataloging tools. NAO is directed at the specific context of scientific computing. Because the type of tools is restricted, problems such as tools with incompatible data structures for input and output, and dissimilar interfaces to tools which solve similar problems can be addressed. The approach we've taken is to define interfaces to those objects used in numerical analysis, such as geometries, functions and operators, and to start collecting (and building) a set of tools which use these interfaces. We have written a class library (a set of abstract classes and implementations) in C++ which demonstrates the approach. Besides the classes, the class library includes "stub" routines which allow the library to be used from C or Fortran, and an interface to a Visual Programming Language. The library has been used to build a simulator for petroleum reservoirs, using a set of tools for discretizing nonlinear differential equations that we have written, and includes "wrapped" versions of packages from the Netlib repository. Documentation can be found on the Web at "http://www.research.ibm.com/nao". I will describe the objects and their interfaces, and give examples ranging from mesh generation to solving differential equations.

  10. The Language of Objects

    DEFF Research Database (Denmark)

    Eskildsen, Kasper Risbjerg

    2012-01-01

    The Danish amateur scholar Christian Jürgensen Thomsen has often been described as a founder of modern “scientific” archaeology. Thomsen's innovation, this essay argues, reflects developments within neighboring fields, such as philology and history. He reacted against historians who limited....... 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...

  11. Remote viewing of objects

    International Nuclear Information System (INIS)

    Motin, J.D.; Reformatsky, I.A.; Sinitsyn, P.R.; Ivanov, N.M.; Ivanov, B.I.; Malakhov, I.K.

    1979-01-01

    An object in a nuclear power plant is viewed through a radiation-proof shield by means of an entrance lens, optic fibre bundle and exit lens. The optic fibre bundle being heated to ensure thermostabilization of its light conducting properties in the presence of ionising radiation. Heating is by an electric heating coil. Alternatively, heating may be by argon itself heated by an electric heating element, a coating of resistive heating material, or absorption of neutrons in the material of the fibres or a coating therefor. Viewing may be on a CRT screen. (author)

  12. 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...

  13. Object-Based Benefits without Object-Based Representations

    OpenAIRE

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

    2012-01-01

    The organization of visual information into objects strongly influences visual memory: Displays with objects defined by two features (e.g. color, orientation) are easier to remember than displays with twice as many objects defined by one feature (Olson & Jiang, 2002). Existing theories suggest that this ‘object-benefit’ is based on object-based limitations in working memory: because a limited number of objects can be stored, packaging features together so that fewer objects have to be remembe...

  14. Object linking in repositories

    Science.gov (United States)

    Eichmann, David (Editor); Beck, Jon; Atkins, John; Bailey, Bill

    1992-01-01

    This topic is covered in three sections. The first section explores some of the architectural ramifications of extending the Eichmann/Atkins lattice-based classification scheme to encompass the assets of the full life cycle of software development. A model is considered that provides explicit links between objects in addition to the edges connecting classification vertices in the standard lattice. The second section gives a description of the efforts to implement the repository architecture using a commercially available object-oriented database management system. Some of the features of this implementation are described, and some of the next steps to be taken to produce a working prototype of the repository are pointed out. In the final section, it is argued that design and instantiation of reusable components have competing criteria (design-for-reuse strives for generality, design-with-reuse strives for specificity) and that providing mechanisms for each can be complementary rather than antagonistic. In particular, it is demonstrated how program slicing techniques can be applied to customization of reusable components.

  15. Review of Meeting Objectives

    International Nuclear Information System (INIS)

    Braams, B.J.; Chung, H.-K.

    2011-01-01

    This is the 21st meeting of the International Atomic and Molecular Data Centres Network. The traditional DCN meeting objectives are: to exchange information about activities in the Centres and review progress; to coordinate work in the Centres; to assess priorities in data evaluation and data production; to make plans for specific evaluations; and to evaluate and revise procedures for collection and exchange of bibliographical and numerical data. All of these are objectives for the present meeting too. In addition to the presentations from DCN and prospective DCN members we have two participants from outside the field of fusion data: Dr N. Mason will tell us about coordination of the Virtual Atomic and Molecular Data Centre and Dr S. Simakov will describe the manner in which nuclear structure and cross-section database development is coordinated by our colleagues in the Nuclear Data Section. In the discussions on Thursday and Friday there are two topics that need special attention this year: the future of our bibliographical data compilation and ways in which we can strengthen data evaluation activities, all with emphasis on collision processes and plasma-material interaction. The first 3 Data Centre Network meetings were held in 1977, 1980 and 1982 and the reports of those meetings make interesting reading and can still provide inspiration for the present meeting. I show some excerpts in the presentation. In 1977 the emphasis was on the coordination of the bibliographical database, AMBDAS, and a collision data index, CIAMDA, as the initial activities of the Network and of the newly formed IAEA A+M Data Unit. In 1980 the central topic of discussion at the meeting shifted to the numerical database and to data evaluation. The Network recommended that numerical data be reviewed by a selected group of scientists and that no unevaluated numerical A+M collision data should be distributed by the IAEA. The report of the meeting in 1982 shows that the bibliographical

  16. Objectives of the symposium

    International Nuclear Information System (INIS)

    Genter, N.E.

    1996-01-01

    The objective of this symposium was to discuss the sorts of evidence of molecular alterations in DNA which can be used to study causation of the stochastic effects of importance in radiation protection. Specifically, the aim was to address the following: what sort of indications might show whether a cancer was caused by radiation; whether there is a radiogenic signature to distinguish damage caused by ionizing radiation; whether bio-markers might be available for susceptibility, for exposure, for biological consequences. Despite a number of epidemiological studies (referred to), there is no clear, credible, defensible answer as to whether low-level radiation increases the risk of cancer. A new ethical question is, what rules should be in place for identifying and protecting genetically sensitive individuals. 1 tab

  17. Objectives of the symposium

    International Nuclear Information System (INIS)

    Osborne, R.V.

    1992-01-01

    The author defined the objectives of the symposium as follows: to present and examine the recent evidence associating clusters of leukemia with sources of ionizing radiation; to examine the statistical basis for the analysis of clustering; to examine the underlying assumptions in epidemiological studies that clusters must have an environmental cause; to examine the extent to which we can take into account the biological causes of non-randomness in populations, particularly those of geographic and genetic origin; to evaluate the relative merits of different kinds of epidemiological studies for yielding significant information concerning clustering; to consider the potential utility of combining the results from existing studies, and whether new epidemiological studies might be helpful; to consider what other directions, including application of the technologies of molecular biology, are likely to help clarify the underlying mechanisms or causes

  18. Breaking object correspondence across saccadic eye movements deteriorates object recognition

    Directory of Open Access Journals (Sweden)

    Christian H. Poth

    2015-12-01

    Full Text Available Visual perception is based on information processing during periods of eye fixations that are interrupted by fast saccadic eye movements. The ability to sample and relate information on task-relevant objects across fixations implies that correspondence between presaccadic and postsaccadic objects is established. Postsaccadic object information usually updates and overwrites information on the corresponding presaccadic object. The presaccadic object representation is then lost. In contrast, the presaccadic object is conserved when object correspondence is broken. This helps transsaccadic memory but it may impose attentional costs on object recognition. Therefore, we investigated how breaking object correspondence across the saccade affects postsaccadic object recognition. In Experiment 1, object correspondence was broken by a brief postsaccadic blank screen. Observers made a saccade to a peripheral object which was displaced during the saccade. This object reappeared either immediately after the saccade or after the blank screen. Within the postsaccadic object, a letter was briefly presented (terminated by a mask. Observers reported displacement direction and letter identity in different blocks. Breaking object correspondence by blanking improved displacement identification but deteriorated postsaccadic letter recognition. In Experiment 2, object correspondence was broken by changing the object’s contrast-polarity. There were no object displacements and observers only reported letter identity. Again, breaking object correspondence deteriorated postsaccadic letter recognition. These findings identify transsaccadic object correspondence as a key determinant of object recognition across the saccade. This is in line with the recent hypothesis that breaking object correspondence results in separate representations of presaccadic and postsaccadic objects which then compete for limited attentional processing resources (Schneider, 2013. Postsaccadic

  19. Toxic Potential of Synthesized Graphene Zinc Oxide Nanocomposite in the Third Instar Larvae of Transgenic Drosophila melanogaster (hsp70-lacZBg9

    Directory of Open Access Journals (Sweden)

    Yasir Hasan Siddique

    2014-01-01

    Full Text Available In the present study the graphene zinc oxide nanocomposite (GZNC was synthesized, characterized, and evaluated for its toxic potential on third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZBg9. The synthesized GZNC was characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The GZNC in 0.1% dimethyl sulphoxide (DMSO was sonicated for 10 minutes and the final concentrations 0.033, 0.099, 0.199, and 3.996 μg/μL of diet were established. The third instar larvae were allowed to feed on it separately for 24 and 48 hr. The hsp70 expression was measured by o-nitrophenyl-β-D-galactopyranoside assay, tissue damage was measured by trypan blue exclusion test, and β-galactosidase activity was monitored by in situ histochemical β-galactosidase staining. Oxidative stress was monitored by performing lipid peroxidation assay and total protein estimation. Ethidium bromide/acridine orange staining was performed on midgut cells for apoptotic index and the comet assay was performed for the DNA damage. The results of the present study showed that the exposure of 0.199 and 3.996 μg/μL of GZNC was toxic for both 24 hr and 48 hr of exposure. The doses of 0.033 μg/μL and 0.099 of GZNC showed no toxic effects on its exposure to the third instar larvae for 24 hr as well as 48 hr of duration.

  20. Data quality objectives

    International Nuclear Information System (INIS)

    Haeberer, F.

    1993-01-01

    The U.S. Environmental Protection Agency (EPA) spends about $500 million annually in collecting environmental data for scientific research and regulatory decision making. In addition, the regulated community may spend as much as ten times more each year in responding to EPA compliance requirements. Among the EPA and the regulated community there are several important common concerns: both want to make informed decisions using the right type, quality, and quantity of data. Collecting new data is very resource intensive to all parties. Neither EPA nor the regulated community can afford to collect more or open-quotes betterclose quotes data than are really needed; the Data Quality Objectives (DQO) process is a systematic planning tool for ensuring that the right data will be collected for arriving at a decision within the desired confidence constraints. Using the DQO process to plan environmental data collections can help improve their effectiveness and efficiency, and enhance the defensibility of the decisions for which the data are used

  1. Data quality objectives

    Energy Technology Data Exchange (ETDEWEB)

    Haeberer, F. [Environmental Protection Agency, Washington, DC (United States)

    1993-12-31

    The U.S. Environmental Protection Agency (EPA) spends about $500 million annually in collecting environmental data for scientific research and regulatory decision making. In addition, the regulated community may spend as much as ten times more each year in responding to EPA compliance requirements. Among the EPA and the regulated community there are several important common concerns: both want to make informed decisions using the right type, quality, and quantity of data. Collecting new data is very resource intensive to all parties. Neither EPA nor the regulated community can afford to collect more or {open_quotes}better{close_quotes} data than are really needed; the Data Quality Objectives (DQO) process is a systematic planning tool for ensuring that the right data will be collected for arriving at a decision within the desired confidence constraints. Using the DQO process to plan environmental data collections can help improve their effectiveness and efficiency, and enhance the defensibility of the decisions for which the data are used.

  2. Beyond the Object

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Object orientation (OO is regained not only in all components of integrate development media but it remarks in the rest of software world from operating system to last application domain - of course, with different intensity and success. A clear prove of OO application in all situations is the development of a wide range of industrial applications. OO technology allows drawing of relation between the geometry, topology and dimensions of data on a class hierarchy; thus, the observation of the amount of data gained by research in many scientific domains is facilitated through class libraries both for graphic primitives and for events examination. In conformity to all waiting, OO asserts in every distributive system, there are very important the applications for making open systems customer-server and dis-tributed applications in Java. Finally OO application in robot's programming and modeling needn't be omitted. However, far to be panacea, OO has also shades which will be researched so on.

  3. Workshop objectives and structure

    International Nuclear Information System (INIS)

    2004-01-01

    The overall aim of the Workshop was to create a platform in order to better understand different approaches to managing uncertainty in post-closure safety cases and regulatory approaches in different national waste management programmes. The principal objectives of the Workshop were to: - To identify common elements in different approaches for managing uncertainty. - To facilitate information exchange and to promote discussion on different technical approaches to the management and characterisation of uncertainty and on the role of risk. - To explore the merits of alternative approaches to risk-informed decision making. - To identify the potential for further developments of methods or strategies to support the management of uncertainties. The workshop was organised into plenary sessions and working group discussions: The first plenary session focused on establishing a framework for understanding the management of uncertainties and the use of risk. It comprised oral presentations drawing on a range of experience from both active participants in the development and assessment of safety cases and keynotes presentations by external participants involved in risk management in other sectors. The working group discussions covered three technical themes: Risk management and decision making. Regulatory requirements and review of uncertainty and risk in safety cases. Practical approaches and tools for the management of uncertainties and the assignment of probabilities, the use of expert judgements, and the presentation of information on uncertainties and risk were examined. The aim of the working groups was to develop an understanding of the specific issues, and to identify any further activities that will support the development and/or evaluation of safety cases. The round up plenary session brought together information and conclusions from each of the working groups. Common elements in the different approaches to treating uncertainty and risk were identified, along with

  4. Effects of Selected Object Characteristics on Object Permanence Test Performance.

    Science.gov (United States)

    Lingle, Kathleen M.; Lingle, John H.

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

  5. Tracking in Object Action Space

    DEFF Research Database (Denmark)

    Krüger, Volker; Herzog, Dennis

    2013-01-01

    the space of the object affordances, i.e., the space of possible actions that are applied on a given object. This way, 3D body tracking reduces to action tracking in the object (and context) primed parameter space of the object affordances. This reduces the high-dimensional joint-space to a low...

  6. Object grammars and random generation

    Directory of Open Access Journals (Sweden)

    I. Dutour

    1998-12-01

    Full Text Available This paper presents a new systematic approach for the uniform random generation of combinatorial objects. The method is based on the notion of object grammars which give recursive descriptions of objects and generalize context-freegrammars. The application of particular valuations to these grammars leads to enumeration and random generation of objects according to non algebraic parameters.

  7. Visual object recognition and tracking

    Science.gov (United States)

    Chang, Chu-Yin (Inventor); English, James D. (Inventor); Tardella, Neil M. (Inventor)

    2010-01-01

    This invention describes a method for identifying and tracking an object from two-dimensional data pictorially representing said object by an object-tracking system through processing said two-dimensional data using at least one tracker-identifier belonging to the object-tracking system for providing an output signal containing: a) a type of the object, and/or b) a position or an orientation of the object in three-dimensions, and/or c) an articulation or a shape change of said object in said three dimensions.

  8. First-Class Object Sets

    DEFF Research Database (Denmark)

    Ernst, Erik

    Typically, objects are monolithic entities with a fixed interface. To increase the flexibility in this area, this paper presents first-class object sets as a language construct. An object set offers an interface which is a disjoint union of the interfaces of its member objects. It may also be used...... for a special kind of method invocation involving multiple objects in a dynamic lookup process. With support for feature access and late-bound method calls object sets are similar to ordinary objects, only more flexible. The approach is made precise by means of a small calculus, and the soundness of its type...

  9. SURVEY, MILLE LACS COUNTY, MN

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Survey data includes spatial datasets and data tables necessary to digitally represent data collected in the survey phase of the study. (Source: FEMA Guidelines and...

  10. Object width modulates object-based attentional selection.

    Science.gov (United States)

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

    2018-04-24

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

  11. Adobe Boxes: Locating Object Proposals Using Object Adobes.

    Science.gov (United States)

    Fang, Zhiwen; Cao, Zhiguo; Xiao, Yang; Zhu, Lei; Yuan, Junsong

    2016-09-01

    Despite the previous efforts of object proposals, the detection rates of the existing approaches are still not satisfactory enough. To address this, we propose Adobe Boxes to efficiently locate the potential objects with fewer proposals, in terms of searching the object adobes that are the salient object parts easy to be perceived. Because of the visual difference between the object and its surroundings, an object adobe obtained from the local region has a high probability to be a part of an object, which is capable of depicting the locative information of the proto-object. Our approach comprises of three main procedures. First, the coarse object proposals are acquired by employing randomly sampled windows. Then, based on local-contrast analysis, the object adobes are identified within the enlarged bounding boxes that correspond to the coarse proposals. The final object proposals are obtained by converging the bounding boxes to tightly surround the object adobes. Meanwhile, our object adobes can also refine the detection rate of most state-of-the-art methods as a refinement approach. The extensive experiments on four challenging datasets (PASCAL VOC2007, VOC2010, VOC2012, and ILSVRC2014) demonstrate that the detection rate of our approach generally outperforms the state-of-the-art methods, especially with relatively small number of proposals. The average time consumed on one image is about 48 ms, which nearly meets the real-time requirement.

  12. Some aspects of the reproductive biology of the twaite shad, Alosa fallax (Lacépède, 1803, in the River Ulla (Northwest of the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    David J. Nachón

    2015-11-01

    Full Text Available Evaluation of fecundity is a key step to quantify the reproductive potential of individual fish and to understand the stock-recruitment relationship, increasing the knowledge of the state of a stock and improving the assessment of the spawning stock biomass. For the present work we investigated the fecundity and gonad development in anadromous female twaite shad, Alosa fallax (Lacépède, 1803, during the upstream spawning migration in the River Ulla. Thirty-four females were sampled with trammel nets between April and June 2011 in seating areas for this species, located at 24 km and 20 km from the Atlantic Ocean respectively. Fish were lengthed to the nearest millimetre, weighed to the nearest gram and aged by using scales. Factor condition (K was estimated as K= (TW/TL^3*100 where TW is fish total weight (g and TL is fish total length (cm. The ovaries from each female were removed and weighted to the nearest 0.01 gram. Approximately one gram samples were taken from the anterior, central and posterior regions of each ovary and preserved in 70 % ethanol. The number of eggs in each subsample was counted and the fecundity computed from the mean. Individual fecundity (F was computed and F was divided by the weight of the fish to estimate relative fecundity (FR. Also the gonadosomatic index (GSI was calculated to assess changes in fish maturity and spawning stage during the upstream migration. Female age ranged from 4 to 7 years and values of TL, TW, K and GSI were [mean ± SE (range]: 493 ± 7.3 mm (408-562 mm; 1,112 ± 53.7 g (592-1,626 g; 0.91 ± 0.02 (0.67-1.09 and 12.5 ± 0.47 (6.6-21.4 respectively. The value of fecundity (F was [mean ± SE (range]: 96,471 ± 6,493 oocytes (24,962 to 182,154 oocytes, while the relative fecundity (Fr was [mean ± SE (range]: 87,142 ± 3,592 oocytes (25,319 to 129,189 oocytes. A significant correlation (Spearman´s ρ test, p<0.05 between fecundity and all parameters has been determined. As observed in previous

  13. Copépodes, Cladocères et Rotifères du lac Sidi M'hamed Benali (Algérie Nord-Occidentale

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Bouzidi

    2010-03-01

    Full Text Available En 2008, 33 espèces de Cladocères, Copépodes et Rotifères ont été observées dans le lac Sidi M'hamed Benali (contre 12 seulement en 1992.Les Copépodes dominent en mars, avril, juillet, août et septembre, avec respectivement des dominances (Do égales à : 56,6 %, 55,0 %, 55,0 %, 46,4 % et 90,0 %. Les Cladocères dominent en février (Do = 37,2 %, mai (Do = 47,4 % et décembre (Do = 48,6 %. Les Rotifères sont extrêmement abondants et présentent une large dominance en janvier (Do = 95,3 %. La population zooplanctonique est très faible en juillet et en août. Au cours de l'année le peuplement varie en fonction de la température, des conditions hydrologiques, de l'abondance de la nourriture et de la prédation par les poissons.In 2008, 33 species of Cladocers, Copepods and Rotifers have been observed in Sidi M’hamed Benali Lake (against only 12 species in 1992. The Copepods dominate in March, April, July, August and September, respectively with dominance (Do equal to 56.6 %, 55.0 %, 55.0 %, 46.4 % and 90.0 %. Cladocers dominated in February (Do = 37.2 %, May (Do = 47.4 % and December (Do = 48.6 %. The rotifers are extremely abundant and have a wide dominance in January (Do = 95.3%. The zooplankton population is very low in July and August. During the year, the population varies with temperature, water conditions, abundance of food and predation by fishes.

  14. The NifA-RpoN regulon of Mesorhizobium loti strain R7A and its symbiotic activation by a novel LacI/GalR-family regulator.

    Directory of Open Access Journals (Sweden)

    John T Sullivan

    Full Text Available Mesorhizobium loti is the microsymbiont of Lotus species, including the model legume L. japonicus. M. loti differs from other rhizobia in that it contains two copies of the key nitrogen fixation regulatory gene nifA, nifA1 and nifA2, both of which are located on the symbiosis island ICEMlSym(R7A. M. loti R7A also contains two rpoN genes, rpoN1 located on the chromosome outside of ICEMlSym(R7A and rpoN2 that is located on ICEMlSym(R7A. The aims of the current work were to establish how nifA expression was activated in M. loti and to characterise the NifA-RpoN regulon. The nifA2 and rpoN2 genes were essential for nitrogen fixation whereas nifA1 and rpoN1 were dispensable. Expression of nifA2 was activated, possibly in response to an inositol derivative, by a novel regulator of the LacI/GalR family encoded by the fixV gene located upstream of nifA2. Other than the well-characterized nif/fix genes, most NifA2-regulated genes were not required for nitrogen fixation although they were strongly expressed in nodules. The NifA-regulated nifZ and fixU genes, along with nifQ which was not NifA-regulated, were required in M. loti for a fully effective symbiosis although they are not present in some other rhizobia. The NifA-regulated gene msi158 that encodes a porin was also required for a fully effective symbiosis. Several metabolic genes that lacked NifA-regulated promoters were strongly expressed in nodules in a NifA2-dependent manner but again mutants did not have an overt symbiotic phenotype. In summary, many genes encoded on ICEMlSym(R7A were strongly expressed in nodules but not free-living rhizobia, but were not essential for symbiotic nitrogen fixation. It seems likely that some of these genes have functional homologues elsewhere in the genome and that bacteroid metabolism may be sufficiently plastic to adapt to loss of certain enzymatic functions.

  15. A quantitative study of methanol/sorbitol co-feeding process of a Pichia pastoris Mut⁺/pAOX1-lacZ strain.

    Science.gov (United States)

    Niu, Hongxing; Jost, Laurent; Pirlot, Nathalie; Sassi, Hosni; Daukandt, Marc; Rodriguez, Christian; Fickers, Patrick

    2013-04-08

    One of the main challenges for heterologous protein production by the methylotrophic yeast Pichia pastoris at large-scale is related to its high oxygen demand. A promising solution is a co-feeding strategy based on a methanol/sorbitol mixture during the induction phase. Nonetheless, a deep understanding of the cellular physiology and the regulation of the AOX1 promoter, used to govern heterologous protein production, during this co-feeding strategy is still scarce. Transient continuous cultures with a dilution rate of 0.023 h(-1) at 25°C were performed to quantitatively assess the benefits of a methanol/sorbitol co-feeding process with a Mut+ strain in which the pAOX1-lacZ construct served as a reporter gene. Cell growth and metabolism, including O2 consumption together with CO2 and heat production were analyzed with regard to a linear change of methanol fraction in the mixed feeding media. In addition, the regulation of the promoter AOX1 was investigated by means of β-galactosidase measurements. Our results demonstrated that the cell-specific oxygen consumption (qO2) could be reduced by decreasing the methanol fraction in the feeding media. More interestingly, maximal β-galactosidase cell-specific activity (>7500 Miller unit) and thus, optimal pAOX1 induction, was achieved and maintained in the range of 0.45 ~ 0.75 C-mol/C-mol of methanol fraction. In addition, the qO2 was reduced by 30% at most in those conditions. Based on a simplified metabolic network, metabolic flux analysis (MFA) was performed to quantify intracellular metabolic flux distributions during the transient continuous cultures, which further shed light on the advantages of methanol/sorbitol co-feeding process. Finally, our observations were further validated in fed-batch cultures. This study brings quantitative insight into the co-feeding process, which provides valuable data for the control of methanol/sorbitol co-feeding, aiming at enhancing biomass and heterologous protein productivities

  16. A quantitative study of methanol/sorbitol co-feeding process of a Pichia pastoris Mut+/pAOX1-lacZ strain

    Science.gov (United States)

    2013-01-01

    Background One of the main challenges for heterologous protein production by the methylotrophic yeast Pichia pastoris at large-scale is related to its high oxygen demand. A promising solution is a co-feeding strategy based on a methanol/sorbitol mixture during the induction phase. Nonetheless, a deep understanding of the cellular physiology and the regulation of the AOX1 promoter, used to govern heterologous protein production, during this co-feeding strategy is still scarce. Results Transient continuous cultures with a dilution rate of 0.023 h-1 at 25°C were performed to quantitatively assess the benefits of a methanol/sorbitol co-feeding process with a Mut+ strain in which the pAOX1-lacZ construct served as a reporter gene. Cell growth and metabolism, including O2 consumption together with CO2 and heat production were analyzed with regard to a linear change of methanol fraction in the mixed feeding media. In addition, the regulation of the promoter AOX1 was investigated by means of β-galactosidase measurements. Our results demonstrated that the cell-specific oxygen consumption (qO2) could be reduced by decreasing the methanol fraction in the feeding media. More interestingly, maximal β-galactosidase cell-specific activity (>7500 Miller unit) and thus, optimal pAOX1 induction, was achieved and maintained in the range of 0.45 ~ 0.75 C-mol/C-mol of methanol fraction. In addition, the qO2 was reduced by 30% at most in those conditions. Based on a simplified metabolic network, metabolic flux analysis (MFA) was performed to quantify intracellular metabolic flux distributions during the transient continuous cultures, which further shed light on the advantages of methanol/sorbitol co-feeding process. Finally, our observations were further validated in fed-batch cultures. Conclusion This study brings quantitative insight into the co-feeding process, which provides valuable data for the control of methanol/sorbitol co-feeding, aiming at enhancing biomass and

  17. The LacI–Family Transcription Factor, RbsR, Is a Pleiotropic Regulator of Motility, Virulence, Siderophore and Antibiotic Production, Gas Vesicle Morphogenesis and Flotation in Serratia

    Directory of Open Access Journals (Sweden)

    Chin M. Lee

    2017-09-01

    Full Text Available Gas vesicles (GVs are proteinaceous, gas-filled organelles used by some bacteria to enable upward movement into favorable air/liquid interfaces in aquatic environments. Serratia sp. ATCC39006 (S39006 was the first enterobacterium discovered to produce GVs naturally. The regulation of GV assembly in this host is complex and part of a wider regulatory network affecting various phenotypes, including antibiotic biosynthesis. To identify new regulators of GVs, a comprehensive mutant library containing 71,000 insertion mutants was generated by random transposon mutagenesis and 311 putative GV-defective mutants identified. Three of these mutants were found to have a transposon inserted in a LacI family transcription regulator gene (rbsR of the putative ribose operon. Each of these rbsR mutants was GV-defective; no GVs were visible by phase contrast microscopy (PCM or transmission electron microscopy (TEM. GV deficiency was caused by the reduction of gvpA1 and gvrA transcription (the first genes of the two contiguous operons in the GV gene locus. Our results also showed that a mutation in rbsR was highly pleiotropic; the production of two secondary metabolites (carbapenem and prodigiosin antibiotics was abolished. Interestingly, the intrinsic resistance to the carbapenem antibiotic was not affected by the rbsR mutation. In addition, the production of a siderophore, cellulase and plant virulence was reduced in the mutant, whereas it exhibited increased swimming and swarming motility. The RbsR protein was predicted to bind to regions upstream of at least 18 genes in S39006 including rbsD (the first gene of the ribose operon and gvrA. Electrophoretic mobility shift assays (EMSA confirmed that RbsR bound to DNA sequences upstream of rbsD, but not gvrA. The results of this study indicate that RbsR is a global regulator that affects the modulation of GV biogenesis, but also with complex pleiotropic physiological impacts in S39006.

  18. Implications of perspective in teaching objects first and object design

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2005-01-01

    There are an increasing number of books published on the important topics of "object-oriented programming" and "object-oriented design" for use in education. However, object-orientation can be viewed from a number of different perspectives---each perspective having its benefits and liabilities...

  19. Relativistic Beaming and Orientation Effects in BL Lacertae Objects ...

    Indian Academy of Sciences (India)

    tation paradigm for high peaked and low-peaked BL Lacs (X-ray and radio selected .... consequences of relativistic beaming and geometric projection were studied in high- ... model. If we assume α = 0 (for synchrotron self-absorbed sources) and β ∼ 1, it can .... for RBL and XBL subsamples at confidence level of ∼ 95.0%.

  20. Two Types of Visual Objects

    Directory of Open Access Journals (Sweden)

    Skrzypulec Błażej

    2015-06-01

    Full Text Available While it is widely accepted that human vision represents objects, it is less clear which of the various philosophical notions of ‘object’ adequately characterizes visual objects. In this paper, I show that within contemporary cognitive psychology visual objects are characterized in two distinct, incompatible ways. On the one hand, models of visual organization describe visual objects in terms of combinations of features, in accordance with the philosophical bundle theories of objects. However, models of visual persistence apply a notion of visual objects that is more similar to that endorsed in philosophical substratum theories. Here I discuss arguments that might show either that only one of the above notions of visual objects is adequate in the context of human vision, or that the category of visual objects is not uniform and contains entities properly characterized by different philosophical conceptions.

  1. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-11-09

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  2. Foreign Objects in the Rectum

    Science.gov (United States)

    ... Abscess Anorectal Fistula Foreign Objects in the Rectum Hemorrhoids Levator Syndrome Pilonidal Disease Proctitis Rectal Prolapse (See ... Abscess Anorectal Fistula Foreign Objects in the Rectum Hemorrhoids Levator Syndrome Pilonidal Disease Proctitis Rectal Prolapse NOTE: ...

  3. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-01-08

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  4. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong; Sundaramoorthi, Ganesh

    2017-01-01

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  5. Object Knowledge Modulates Colour Appearance

    Directory of Open Access Journals (Sweden)

    Christoph Witzel

    2011-01-01

    Full Text Available We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis.

  6. Object knowledge modulates colour appearance

    Science.gov (United States)

    Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

    2011-01-01

    We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis. PMID:23145224

  7. A Model for Concurrent Objects

    DEFF Research Database (Denmark)

    Sørensen, Morten U.

    1996-01-01

    We present a model for concurrent objects where obejcts interact by taking part in common events that are closely matched to form call-response pairs, resulting in resulting in rendez-vous like communications. Objects are built from primitive objects by parallel composition, encapsulation...

  8. Decoupling Object Detection and Categorization

    Science.gov (United States)

    Mack, Michael L.; Palmeri, Thomas J.

    2010-01-01

    We investigated whether there exists a behavioral dependency between object detection and categorization. Previous work (Grill-Spector & Kanwisher, 2005) suggests that object detection and basic-level categorization may be the very same perceptual mechanism: As objects are parsed from the background they are categorized at the basic level. In…

  9. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong; Sundaramoorthi, Ganesh

    2017-01-01

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon

  10. SODA: Smart Objects, Dumb Archives

    Science.gov (United States)

    Nelson, Michael L.; Maly, Kurt; Zubair, Mohammad; Shen, Stewart N. T.

    2004-01-01

    We present the Smart Object, Dumb Archive (SODA) model for digital libraries (DLs). The SODA model transfers functionality traditionally associated with archives to the archived objects themselves. We are exploiting this shift of responsibility to facilitate other DL goals, such as interoperability, object intelligence and mobility, and heterogeneity. Objects in a SODA DL negotiate presentation of content and handle their own terms and conditions. In this paper we present implementations of our smart objects, buckets, and our dumb archive (DA). We discuss the status of buckets and DA and how they are used in a variety of DL projects.

  11. Major facilitator superfamily porters, LacY, FucP and XylE of Escherichia coli appear to have evolved positionally dissimilar catalytic residues without rearrangement of 3-TMS repeat units.

    Science.gov (United States)

    Västermark, Ake; Lunt, Bryan; Saier, Milton

    2014-01-01

    Based on alleged functional residue correspondences between FucP and LacY, a recent study has resulted in a proposed model of 3-TMS unit rearrangements [Madej et al.: Proc Natl Acad Sci USA 2013;110:5870-5874]. We rebut this theory, using 7 different lines of evidence. Our observations suggest that these two transporters are homologous throughout their lengths, having evolved from a common ancestor without repeat unit rearrangements. We exploit the availability of the high-resolution XylE crystal structures in multiple conformations including the inward-facing state to render possible direct comparisons with LacY. Based on a Δdistance map, we confirm the conclusion of Quistgaard et al. [Nat Struct Mol Biol 2013;20:766-768] that the N-terminal 6 TMS halves of these transporters are internally less mobile than the second halves during the conformational transition from the outward occluded state to the inward occluded state and inward occluded state to inward open state. These observations, together with those of Madej et al. [2013], lead to the suggestion that functionally equivalent catalytic residues involved in substrate binding and transport catalysis have evolved in dissimilar positions, but apparently often in similar positions in the putative 3-TMS repeat units, from a single structural scaffold without intragenic rearrangement. © 2014 S. Karger AG, Basel.

  12. Major Facilitator Superfamily (MFS) Porters, LacY, FucP and XylE of Escherichia coli Appear to have Evolved Positionally Dissimilar Catalytic Residues without Rearrangement of 3-TMS Repeat Units

    Science.gov (United States)

    Västermark, Åke; Lunt, Bryan; Saier, Milton

    2014-01-01

    Based on alleged functional residue correspondences between FucP and LacY, a recent study has resulted in a proposed model of 3-TMS unit rearrangements [Madej et al., 2013]. We rebut this theory, using seven different lines of evidence. Our observations suggest that these two transporters are homologous throughout their lengths, having evolved from a common ancestor without repeat unit rearrangements. We exploit the availability of the high resolution XylE crystal structures in multiple conformations including the inward facing state to render possible direct comparisons with LacY. Based on a Δdistance map, we confirm the conclusion of Quistgaard et al. 2013 that the N-terminal 6 TMS halves of these transporters are internally less mobile than the second halves during the conformational transition from the outward occluded state to the inward occluded state and inward occluded state to inward open state. These observations, together with those of Madej et al., 2013, lead to the suggestion that functionally equivalent catalytic residues involved in substrate binding and transport catalysis have evolved in dissimilar positions, but apparently often in similar positions in the putative 3-TMS repeat units, from a single structural scaffold without intragenic rearrangement. PMID:24603210

  13. Transcription of two adjacent carbohydrate utilization gene clusters in Bifidobacterium breve UCC2003 is controlled by LacI- and repressor open reading frame kinase (ROK)-type regulators.

    Science.gov (United States)

    O'Connell, Kerry Joan; Motherway, Mary O'Connell; Liedtke, Andrea; Fitzgerald, Gerald F; Paul Ross, R; Stanton, Catherine; Zomer, Aldert; van Sinderen, Douwe

    2014-06-01

    Members of the genus Bifidobacterium are commonly found in the gastrointestinal tracts of mammals, including humans, where their growth is presumed to be dependent on various diet- and/or host-derived carbohydrates. To understand transcriptional control of bifidobacterial carbohydrate metabolism, we investigated two genetic carbohydrate utilization clusters dedicated to the metabolism of raffinose-type sugars and melezitose. Transcriptomic and gene inactivation approaches revealed that the raffinose utilization system is positively regulated by an activator protein, designated RafR. The gene cluster associated with melezitose metabolism was shown to be subject to direct negative control by a LacI-type transcriptional regulator, designated MelR1, in addition to apparent indirect negative control by means of a second LacI-type regulator, MelR2. In silico analysis, DNA-protein interaction, and primer extension studies revealed the MelR1 and MelR2 operator sequences, each of which is positioned just upstream of or overlapping the correspondingly regulated promoter sequences. Similar analyses identified the RafR binding operator sequence located upstream of the rafB promoter. This study indicates that transcriptional control of gene clusters involved in carbohydrate metabolism in bifidobacteria is subject to conserved regulatory systems, representing either positive or negative control.

  14. Object recognition memory in zebrafish.

    Science.gov (United States)

    May, Zacnicte; Morrill, Adam; Holcombe, Adam; Johnston, Travis; Gallup, Joshua; Fouad, Karim; Schalomon, Melike; Hamilton, Trevor James

    2016-01-01

    The novel object recognition, or novel-object preference (NOP) test is employed to assess recognition memory in a variety of organisms. The subject is exposed to two identical objects, then after a delay, it is placed back in the original environment containing one of the original objects and a novel object. If the subject spends more time exploring one object, this can be interpreted as memory retention. To date, this test has not been fully explored in zebrafish (Danio rerio). Zebrafish possess recognition memory for simple 2- and 3-dimensional geometrical shapes, yet it is unknown if this translates to complex 3-dimensional objects. In this study we evaluated recognition memory in zebrafish using complex objects of different sizes. Contrary to rodents, zebrafish preferentially explored familiar over novel objects. Familiarity preference disappeared after delays of 5 mins. Leopard danios, another strain of D. rerio, also preferred the familiar object after a 1 min delay. Object preference could be re-established in zebra danios by administration of nicotine tartrate salt (50mg/L) prior to stimuli presentation, suggesting a memory-enhancing effect of nicotine. Additionally, exploration biases were present only when the objects were of intermediate size (2 × 5 cm). Our results demonstrate zebra and leopard danios have recognition memory, and that low nicotine doses can improve this memory type in zebra danios. However, exploration biases, from which memory is inferred, depend on object size. These findings suggest zebrafish ecology might influence object preference, as zebrafish neophobia could reflect natural anti-predatory behaviour. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Soft X-ray observations of two BL Lacertae objects - markarian 421 and 501

    International Nuclear Information System (INIS)

    Singh, K.P.; Garmire, G.P.

    1985-01-01

    This paper reports on the soft X-ray (0.15-2.8 keV) observations of two BL Lacertae-type objects, viz., Mrk 421 and Mrk 501. The observations were made with the low-energy detectors on the HEAO 1 satellite during the period 1977 August-1978 December. Steep, soft X-ray power-law spectra with photon index Gamma = 3 are found for both Mrk 421 and Mrk 501. The power-law models are found to give a significantly better fit than the thermal models to the observed pulse-height spectra of Mrk 421 and Mrk 501. Day-to-day soft X-ray (0.25 keV band) intensity variations are observed only in Mrk 501. No significant change is found in Gamma from both the BL Lac objects during the period of observations. However, the sum of all the X-ray observations from 1976 until 1980 can be understood in terms of two spectral components of variable intensity to account for the X-ray emission observed between 0.15 and 20 keV from Mrk 421 and Mrk 501. 24 references

  16. Channels as Objects in Concurrent Object-Oriented Programming

    Directory of Open Access Journals (Sweden)

    Joana Campos

    2011-10-01

    Full Text Available There is often a sort of a protocol associated to each class, stating when and how certain methods should be called. Given that this protocol is, if at all, described in the documentation accompanying the class, current mainstream object-oriented languages cannot provide for the verification of client code adherence against the sought class behaviour. We have defined a class-based concurrent object-oriented language that formalises such protocols in the form of usage types. Usage types are attached to class definitions, allowing for the specification of (1 the available methods, (2 the tests clients must perform on the result of methods, and (3 the object status - linear or shared - all of which depend on the object's state. Our work extends the recent approach on modular session types by eliminating channel operations, and defining the method call as the single communication primitive in both sequential and concurrent settings. In contrast to previous works, we define a single category for objects, instead of distinct categories for linear and for shared objects, and let linear objects evolve into shared ones. We introduce a standard sync qualifier to prevent thread interference in certain operations on shared objects. We formalise the language syntax, the operational semantics, and a type system that enforces by static typing that methods are called only when available, and by a single client if so specified in the usage type. We illustrate the language via a complete example.

  17. Rough multiple objective decision making

    CERN Document Server

    Xu, Jiuping

    2011-01-01

    Rough Set TheoryBasic concepts and properties of rough sets Rough Membership Rough Intervals Rough FunctionApplications of Rough SetsMultiple Objective Rough Decision Making Reverse Logistics Problem with Rough Interval Parameters MODM based Rough Approximation for Feasible RegionEVRMCCRMDCRM Reverse Logistics Network Design Problem of Suji Renewable Resource MarketBilevel Multiple Objective Rough Decision Making Hierarchical Supply Chain Planning Problem with Rough Interval Parameters Bilevel Decision Making ModelBL-EVRM BL-CCRMBL-DCRMApplication to Supply Chain Planning of Mianyang Co., LtdStochastic Multiple Objective Rough Decision Multi-Objective Resource-Constrained Project Scheduling UnderRough Random EnvironmentRandom Variable Stochastic EVRM Stochastic CCRM Stochastic DCRM Multi-Objective rc-PSP/mM/Ro-Ra for Longtan Hydropower StationFuzzy Multiple Objective Rough Decision Making Allocation Problem under Fuzzy Environment Fuzzy Variable Fu-EVRM Fu-CCRM Fu-DCRM Earth-Rock Work Allocation Problem.

  18. Rethinking the objectivity of ethics

    OpenAIRE

    Kurth, Charles Burke

    2011-01-01

    Commonsense says that morality is objective. But skeptics deny that the normativity and fallibility that characterize this objectivity really exist. I disagree. I develop an account of moral facts that vindicates the objectivity of ethics. Moreover, I do this without relying on either the strong foundational claims of realism and constructivism, or the revisionary logic of expressivism. Instead, I build from a moral psychology that is modest and familiar--one that focuses on the distinctive, ...

  19. Ferromagnetic Objects Magnetovision Detection System.

    Science.gov (United States)

    Nowicki, Michał; Szewczyk, Roman

    2013-12-02

    This paper presents the application of a weak magnetic fields magnetovision scanning system for detection of dangerous ferromagnetic objects. A measurement system was developed and built to study the magnetic field vector distributions. The measurements of the Earth's field distortions caused by various ferromagnetic objects were carried out. The ability for passive detection of hidden or buried dangerous objects and the determination of their location was demonstrated.

  20. Ferromagnetic Objects Magnetovision Detection System

    Directory of Open Access Journals (Sweden)

    Michał Nowicki

    2013-12-01

    Full Text Available This paper presents the application of a weak magnetic fields magnetovision scanning system for detection of dangerous ferromagnetic objects. A measurement system was developed and built to study the magnetic field vector distributions. The measurements of the Earth’s field distortions caused by various ferromagnetic objects were carried out. The ability for passive detection of hidden or buried dangerous objects and the determination of their location was demonstrated.

  1. Objective interpretation as conforming interpretation

    OpenAIRE

    Lidka Rodak

    2011-01-01

    The practical discourse willingly uses the formula of “objective interpretation”, with no regards to its controversial nature that has been discussed in literature.The main aim of the article is to investigate what “objective interpretation” could mean and how it could be understood in the practical discourse, focusing on the understanding offered by judicature.The thesis of the article is that objective interpretation, as identified with textualists’ position, is not possible to uphold, and ...

  2. Cognitive object recognition system (CORS)

    Science.gov (United States)

    Raju, Chaitanya; Varadarajan, Karthik Mahesh; Krishnamurthi, Niyant; Xu, Shuli; Biederman, Irving; Kelley, Troy

    2010-04-01

    We have developed a framework, Cognitive Object Recognition System (CORS), inspired by current neurocomputational models and psychophysical research in which multiple recognition algorithms (shape based geometric primitives, 'geons,' and non-geometric feature-based algorithms) are integrated to provide a comprehensive solution to object recognition and landmarking. Objects are defined as a combination of geons, corresponding to their simple parts, and the relations among the parts. However, those objects that are not easily decomposable into geons, such as bushes and trees, are recognized by CORS using "feature-based" algorithms. The unique interaction between these algorithms is a novel approach that combines the effectiveness of both algorithms and takes us closer to a generalized approach to object recognition. CORS allows recognition of objects through a larger range of poses using geometric primitives and performs well under heavy occlusion - about 35% of object surface is sufficient. Furthermore, geon composition of an object allows image understanding and reasoning even with novel objects. With reliable landmarking capability, the system improves vision-based robot navigation in GPS-denied environments. Feasibility of the CORS system was demonstrated with real stereo images captured from a Pioneer robot. The system can currently identify doors, door handles, staircases, trashcans and other relevant landmarks in the indoor environment.

  3. Intuitive modeling of vaporish objects

    International Nuclear Information System (INIS)

    Sokolov, Dmitry; Gentil, Christian

    2015-01-01

    Attempts to model gases in computer graphics started in the late 1970s. Since that time, there have been many approaches developed. In this paper we present a non-physical method allowing to create vaporish objects like clouds or smoky characters. The idea is to create a few sketches describing the rough shape of the final vaporish object. These sketches will be used as condensation sets of Iterated Function Systems, providing intuitive control over the object. The advantages of the new method are: simplicity, good control of resulting shapes and ease of eventual object animation.

  4. Object 'Ukryttya' 1986-2006

    International Nuclear Information System (INIS)

    Klyuchnikov, A.A.; Krasnov, V.A.; Rud'ko, V.M.; Shcherbin, V.N.

    2006-01-01

    This monograph summarizes the materials pertaining to 'Ukryttya' Object state. The results of researches of fuel containing materials conditions and of forecast of their future behavior are demonstrated, aerosol characterizations, mechanisms of production of liquid radioactive waste, radiation conditions at SO industrial site and NSC assembly site, as well as analysis of 'Ukryttya' Objects environmental impact, are performed. The conditions of 'Ukryttya' Object building structures are described. Preparation and realization of international projects for conversion of 'Ukryttya' Object into an ecologically safe system, including the 'Ukryttya' Implementation Plan (SIP), are considered

  5. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-05-14

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  6. Identification of computer graphics objects

    Directory of Open Access Journals (Sweden)

    Rossinskyi Yu.M.

    2016-04-01

    Full Text Available The article is devoted to the use of computer graphics methods in problems of creating drawings, charts, drafting, etc. The widespread use of these methods requires the development of efficient algorithms for the identification of objects of drawings. The article analyzes the model-making algorithms for this problem and considered the possibility of reducing the time using graphics editing operations. Editing results in such operations as copying, moving and deleting objects specified images. These operations allow the use of a reliable identification of images of objects methods. For information on the composition of the image of the object along with information about the identity and the color should include information about the spatial location and other characteristics of the object (the thickness and style of contour lines, fill style, and so on. In order to enable the pixel image analysis to structure the information it is necessary to enable the initial code image objects color. The article shows the results of the implementation of the algorithm of encoding object identifiers. To simplify the process of building drawings of any kind, and reduce time-consuming, method of drawing objects identification is proposed based on the use as the ID information of the object color.

  7. Aggregating and Disaggregating Flexibility Objects

    DEFF Research Database (Denmark)

    Siksnys, Laurynas; Valsomatzis, Emmanouil; Hose, Katja

    2015-01-01

    In many scientific and commercial domains we encounter flexibility objects, i.e., objects with explicit flexibilities in a time and an amount dimension (e.g., energy or product amount). Applications of flexibility objects require novel and efficient techniques capable of handling large amounts...... and aiming at energy balancing during aggregation. In more detail, this paper considers the complete life cycle of flex-objects: aggregation, disaggregation, associated requirements, efficient incremental computation, and balance aggregation techniques. Extensive experiments based on real-world data from...

  8. Refining Visually Detected Object poses

    DEFF Research Database (Denmark)

    Holm, Preben; Petersen, Henrik Gordon

    2010-01-01

    to the particular object and in order to handle the demand for flexibility, there is an increasing demand for avoiding such dedicated mechanical alignment systems. Rather, it would be desirable to automatically locate and grasp randomly placed objects from tables, conveyor belts or even bins with a high accuracy...

  9. Welding. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…

  10. Welding. Performance Objectives. Basic Course.

    Science.gov (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of eight terminal objectives for a basic welding course. The materials were developed for a 36-week (2 hours daily) course developed to teach the fundamentals of welding shop work, to become familiar with the operation of the welding shop…

  11. What Makes an Object Memorable?

    KAUST Repository

    Dubey, Rachit

    2016-02-19

    Recent studies on image memorability have shed light on what distinguishes the memorability of different images and the intrinsic and extrinsic properties that make those images memorable. However, a clear understanding of the memorability of specific objects inside an image remains elusive. In this paper, we provide the first attempt to answer the question: what exactly is remembered about an image? We augment both the images and object segmentations from the PASCAL-S dataset with ground truth memorability scores and shed light on the various factors and properties that make an object memorable (or forgettable) to humans. We analyze various visual factors that may influence object memorability (e.g. color, visual saliency, and object categories). We also study the correlation between object and image memorability and find that image memorability is greatly affected by the memorability of its most memorable object. Lastly, we explore the effectiveness of deep learning and other computational approaches in predicting object memorability in images. Our efforts offer a deeper understanding of memorability in general thereby opening up avenues for a wide variety of applications. © 2015 IEEE.

  12. Moving eyes and naming objects

    NARCIS (Netherlands)

    Meulen, F.F. van der

    2001-01-01

    The coordination between eye movements and speech was examined while speakers were naming objects. Earlier research has shown that eye movements reflect on the underlying visual attention. Also, eye movements were found to reflect upon not only the visual and conceptual processing of an object, but

  13. [The Object Permanence Fallacy.] Commentary.

    Science.gov (United States)

    Bradley, Ben S.

    1996-01-01

    Suggests that Greenberg's challenge to the centrality of object permanence in developmental thinking reveals that developmentalists' theories about childhood speak about their own self-images. Notes that developmentalists have been guilty of not only the object permanence fallacy but also the genetic fallacy, or the mistaken belief that describing…

  14. Introducing Object-Oriented Programming

    DEFF Research Database (Denmark)

    Caspersen, Michael Edelgaard

    2008-01-01

    The practice of teaching programming at universities, colleges and high schools went through a major change roughly in the mid 1990s: The teaching of objectorientation in introductory courses slowly became mainstream. Fairly soon, the Object First or Objects Early school of thought was formulated...

  15. Objective interpretation as conforming interpretation

    Directory of Open Access Journals (Sweden)

    Lidka Rodak

    2011-12-01

    Full Text Available The practical discourse willingly uses the formula of “objective interpretation”, with no regards to its controversial nature that has been discussed in literature.The main aim of the article is to investigate what “objective interpretation” could mean and how it could be understood in the practical discourse, focusing on the understanding offered by judicature.The thesis of the article is that objective interpretation, as identified with textualists’ position, is not possible to uphold, and should be rather linked with conforming interpretation. And what this actually implies is that it is not the virtue of certainty and predictability – which are usually associated with objectivity- but coherence that makes the foundation of applicability of objectivity in law.What could be observed from the analyses, is that both the phenomenon of conforming interpretation and objective interpretation play the role of arguments in the interpretive discourse, arguments that provide justification that interpretation is not arbitrary or subjective. With regards to the important part of the ideology of legal application which is the conviction that decisions should be taken on the basis of law in order to exclude arbitrariness, objective interpretation could be read as a question “what kind of authority “supports” certain interpretation”? that is almost never free of judicial creativity and judicial activism.One can say that, objective and conforming interpretation are just another arguments used in legal discourse.

  16. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-01-01

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal

  17. What Makes an Object Memorable?

    KAUST Repository

    Dubey, Rachit; Peterson, Joshua; Khosla, Aditya; Yang, Ming-Hsuan; Ghanem, Bernard

    2016-01-01

    Recent studies on image memorability have shed light on what distinguishes the memorability of different images and the intrinsic and extrinsic properties that make those images memorable. However, a clear understanding of the memorability of specific objects inside an image remains elusive. In this paper, we provide the first attempt to answer the question: what exactly is remembered about an image? We augment both the images and object segmentations from the PASCAL-S dataset with ground truth memorability scores and shed light on the various factors and properties that make an object memorable (or forgettable) to humans. We analyze various visual factors that may influence object memorability (e.g. color, visual saliency, and object categories). We also study the correlation between object and image memorability and find that image memorability is greatly affected by the memorability of its most memorable object. Lastly, we explore the effectiveness of deep learning and other computational approaches in predicting object memorability in images. Our efforts offer a deeper understanding of memorability in general thereby opening up avenues for a wide variety of applications. © 2015 IEEE.

  18. Turbulent wakes of fractal objects

    NARCIS (Netherlands)

    Staicu, A.D.; Mazzi, B.; Vassilicos, J.C.; Water, van de W.

    2003-01-01

    Turbulence of a windtunnel flow is stirred using objects that have a fractal structure. The strong turbulent wakes resulting from three such objects which have different fractal dimensions are probed using multiprobe hot-wire anemometry in various configurations. Statistical turbulent quantities are

  19. Taxonomies of Educational Objective Domain

    OpenAIRE

    Eman Ghanem Nayef; Nik Rosila Nik Yaacob; Hairul Nizam Ismail

    2013-01-01

    This paper highlights an effort to study the educational objective domain taxonomies including Bloom’s taxonomy, Lorin Anderson’s taxonomy, and Wilson’s taxonomy. In this study a comparison among these three taxonomies have been done. Results show that Bloom’s taxonomy is more suitable as an analysis tool to Educational Objective domain.

  20. Exploring Power with Object Theatre

    DEFF Research Database (Denmark)

    Ryöppy, Merja; Ylirisku, Salu; Knutz, Eva

    2017-01-01

    This paper explores Object Theatre as an approach to address power in design. We understand power as a relational activity that emerges and is upheld through particular ways of relating (Elias, 1991; Stacey, 2007). The spontaneity in participant actions through Object Theatre exercises renders pr...

  1. Semantic memory in object use.

    Science.gov (United States)

    Silveri, Maria Caterina; Ciccarelli, Nicoletta

    2009-10-01

    We studied five patients with semantic memory disorders, four with semantic dementia and one with herpes simplex virus encephalitis, to investigate the involvement of semantic conceptual knowledge in object use. Comparisons between patients who had semantic deficits of different severity, as well as the follow-up, showed that the ability to use objects was largely preserved when the deficit was mild but progressively decayed as the deficit became more severe. Naming was generally more impaired than object use. Production tasks (pantomime execution and actual object use) and comprehension tasks (pantomime recognition and action recognition) as well as functional knowledge about objects were impaired when the semantic deficit was severe. Semantic and unrelated errors were produced during object use, but actions were always fluent and patients performed normally on a novel tools task in which the semantic demand was minimal. Patients with severe semantic deficits scored borderline on ideational apraxia tasks. Our data indicate that functional semantic knowledge is crucial for using objects in a conventional way and suggest that non-semantic factors, mainly non-declarative components of memory, might compensate to some extent for semantic disorders and guarantee some residual ability to use very common objects independently of semantic knowledge.

  2. Object Oriented Programming in Director

    Directory of Open Access Journals (Sweden)

    Marian DARDALA

    2006-01-01

    Full Text Available Director is one of the most popular authoring software. As software for developing multimedia applications, Director is an object oriented programming environment. A very important issue to develop multimedia applications is the designing of their own classes. This paper presents the particular aspects concerning the available facilities offered by Lingo to design classes and to generate objects.

  3. Object-Oriented Type Systems

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Palsberg, Jens

    a type system that generalizes and explains them. The theory is based on an idealized object-oriented language called BOPL (Basic Object Programming Language), containing common features of the above languages. A type system, type inference algorithm, and typings of inheritance and genericity......Object-Oriented Type Systems Jens Palsberg and Michael I. Schwartzbach Aarhus University, Denmark Type systems are required to ensure reliability and efficiency of software. For object-oriented languages, typing is an especially challenging problem because of inheritance, assignment, and late...... are provided for BOPL. Throughout, the results are related to the languages on which BOPL is based. This text offers advanced undergraduates and professional software developers a sound understanding of the key aspects of object-oriented type systems. All algorithms are implemented in a freely available...

  4. The Surrealist Collection of Objects

    Directory of Open Access Journals (Sweden)

    Pérez, Leticia

    2010-01-01

    Full Text Available In this article I shall discuss the Surrealist collection of objects as a form of art which arises out of mass production forces of the new era. These goods, deeply rooted in the capitalist laws of use-, exchange- and surplus-value, carry in themselves two materialist approaches which end in dialectical materialism. On the one hand, they epitomize the supreme forces of commodity fetishism ingrained in capitalist structures; on the other hand, they arouse unconscious desires which respond to the needs of the society of consumption. Thus, I will explore the act of object-collecting in the most radical Surrealist practices (dream objects, found objects, poème-objets, calligrammes, readymades and Surrealist objects as a way to not only delve into a new art, but also to reflect on societal ongoing transformations and paradoxes.

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

    Science.gov (United States)

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

    2014-05-01

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

  6. Multiparty Compatibility for Concurrent Objects

    Directory of Open Access Journals (Sweden)

    Roly Perera

    2016-06-01

    Full Text Available Objects and actors are communicating state machines, offering and consuming different services at different points in their lifecycle. Two complementary challenges arise when programming such systems. When objects interact, their state machines must be "compatible", so that services are requested only when they are available. Dually, when objects refine other objects, their state machines must be "compliant", so that services are honoured whenever they are promised. In this paper we show how the idea of multiparty compatibility from the session types literature can be applied to both of these problems. We present an untyped language in which concurrent objects are checked automatically for compatibility and compliance. For simple objects, checking can be exhaustive and has the feel of a type system. More complex objects can be partially validated via test cases, leading to a methodology closer to continuous testing. Our proof-of-concept implementation is limited in some important respects, but demonstrates the potential value of the approach and the relationship to existing software development practices.

  7. Conscientious objection in health care

    Directory of Open Access Journals (Sweden)

    Kuře Josef

    2016-12-01

    Full Text Available The paper deals with conscientious objection in health care, addressing the problems of scope, verification and limitation of such refusal, paying attention to ideological agendas hidden behind the right of conscience where the claimed refusal can cause harm or where such a claim is an attempt to impose certain moral values on society or an excuse for not providing health care. The nature of conscientious objection will be investigated and an ethical analysis of conscientious objection will be conducted. Finally some suggestions for health care policy will be proposed.

  8. Object manipulation facilitates kind-based object individuation of shape-similar objects

    DEFF Research Database (Denmark)

    Kingo, Osman Skjold; Krøjgaard, Peter

    2011-01-01

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

  9. Spectral properties of blazars. I. Objects observed in the far-ultraviolet. II. An X-ray observed sample

    International Nuclear Information System (INIS)

    Ghisellini, G.; Maraschi, L.; Treves, A.; Tanzi, E. G.; Milano Universita, Italy; CNR, Istituto di Fisica Cosmica, Milan, Italy)

    1986-01-01

    All blazars observed with the IUE are studied and shown to form a well-defined subgroup according to their spectral properties. These properties are discussed with respect to theoretical models and are compared with those of quasars. Radio, ultraviolet, and X-ray fluxes are used to construct composite spectral indices, and systematic differences between X-ray selected and otherwise selected objects are discussed. It is confirmed that X-ray selected objects have flatter overall spectra, and are therefore weaker radio emitters relative to their X-ray emission than objects selected otherwise. It is found that X-ray selected blazars have the same average X-ray luminosity as blazars selected otherwise and are underluminous at UV and radio frequencies. This finding is used to argue that the radio-weak, X-ray selected BL Lac objects are, in terms of space density, the dominant members of the blazar population. The results are interpreted in the framework of synchrotron emission models involving relativistic plasma jets. 134 references

  10. Spectral properties of blazars. I. Objects observed in the far-ultraviolet. II. An X-ray observed sample

    Energy Technology Data Exchange (ETDEWEB)

    Ghisellini, G.; Maraschi, L.; Treves, A.; Tanzi, E. G.

    1986-11-01

    All blazars observed with the IUE are studied and shown to form a well-defined subgroup according to their spectral properties. These properties are discussed with respect to theoretical models and are compared with those of quasars. Radio, ultraviolet, and X-ray fluxes are used to construct composite spectral indices, and systematic differences between X-ray selected and otherwise selected objects are discussed. It is confirmed that X-ray selected objects have flatter overall spectra, and are therefore weaker radio emitters relative to their X-ray emission than objects selected otherwise. It is found that X-ray selected blazars have the same average X-ray luminosity as blazars selected otherwise and are underluminous at UV and radio frequencies. This finding is used to argue that the radio-weak, X-ray selected BL Lac objects are, in terms of space density, the dominant members of the blazar population. The results are interpreted in the framework of synchrotron emission models involving relativistic plasma jets. 134 references.

  11. Ghost Imaging of Space Objects

    Data.gov (United States)

    National Aeronautics and Space Administration — Ghost imaging is an optical imaging technique that utilizes the correlations between optical fields in two channels. One of the channels contains the object, however...

  12. Delphi FND Application Object Library -

    Data.gov (United States)

    Department of Transportation — Delphi FND Application Object Library contains the following data elements, but are not limited to temporary data tables for the logged in session, information about...

  13. Incremental Visualizer for Visible Objects

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    This paper discusses the integration of database back-end and visualizer front-end into a one tightly coupled system. The main aim which we achieve is to reduce the data pipeline from database to visualization by using incremental data extraction of visible objects in a fly-through scenarios. We...... also argue that passing only relevant data from the database will substantially reduce the overall load of the visualization system. We propose the system Incremental Visualizer for Visible Objects (IVVO) which considers visible objects and enables incremental visualization along the observer movement...... path. IVVO is the novel solution which allows data to be visualized and loaded on the fly from the database and which regards visibilities of objects. We run a set of experiments to convince that IVVO is feasible in terms of I/O operations and CPU load. We consider the example of data which uses...

  14. Object-Oriented Type Systems

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Palsberg, Jens

    binding. Existing languages employ different type systems, and it can be difficult to compare, evaluate and improve them, since there is currently no uniform theory for such languages. This book provides such a theory. The authors review the type systems of Simula, Smalltalk, C++ and Eiffel and present......Object-Oriented Type Systems Jens Palsberg and Michael I. Schwartzbach Aarhus University, Denmark Type systems are required to ensure reliability and efficiency of software. For object-oriented languages, typing is an especially challenging problem because of inheritance, assignment, and late...... a type system that generalizes and explains them. The theory is based on an idealized object-oriented language called BOPL (Basic Object Programming Language), containing common features of the above languages. A type system, type inference algorithm, and typings of inheritance and genericity...

  15. Laser sources for object illumination

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, G.F. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The considerations which formulate the specifications for a laser illuminator are explained, using the example of an underwater object. Depending on the parameters which define the scenario, widely varying laser requirements result.

  16. Topological objects in hadron physics

    International Nuclear Information System (INIS)

    Rho, M.

    1988-01-01

    The notion of topological objects in hadronic physics is discussed, with emphasis on the role of the Wess-Zumino term and induced transmutation of quantum numbers in chiral bag models. Some applications to nuclear systems are given

  17. On the Aging of Objects

    DEFF Research Database (Denmark)

    Andersen, Bjørn Schiermer

    2016-01-01

    The article seeks to develop a new conceptual framework suitable for analysing the ageing processes of objects in modern culture. The basic intuition is that object experience cannot be analysed separately from collective participation. The article focuses on the question of the ‘timeless’ nature...... of modernist design and seeks to understand why modernist objects age more slowly than other objects. First, inspired by the late Durkheim’s account of symbolism, I turn to the experiential effects of collective embeddedness. Second, I enter the field of architectural practices and architectural theory....... Visiting early modernist ideologue Adolf Loos, I seek to understand the modernist attitude as a direct response to experiences of the acceleration of ageing processes characteristic of modern culture. I then try to show how Loos’s explicit awareness of the collective dimension is ignored by the subsequent...

  18. Experimental Object-Oriented Modelling

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius

    through, e.g., technical prototyping and active user involvement. We introduce and examine “experimental object-oriented modelling” as the intersection of these practices. The contributions of this thesis are expected to be within three perspectives on models and modelling in experimental system...... development: Grounding We develop an empirically based conceptualization of modelling and use of models in system development projects characterized by a high degree of uncertainty in requirements and point to implications for tools and techniques for modelling in such a setting. Techniques We introduce......This thesis examines object-oriented modelling in experimental system development. Object-oriented modelling aims at representing concepts and phenomena of a problem domain in terms of classes and objects. Experimental system development seeks active experimentation in a system development project...

  19. Object detection and tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Tian J.

    2017-05-30

    Methods and apparatuses for analyzing a sequence of images for an object are disclosed herein. In a general embodiment, the method identifies a region of interest in the sequence of images. The object is likely to move within the region of interest. The method divides the region of interest in the sequence of images into sections and calculates signal-to-noise ratios for a section in the sections. A signal-to-noise ratio for the section is calculated using the section in the image, a prior section in a prior image to the image, and a subsequent section in a subsequent image to the image. The signal-to-noise ratios are for potential velocities of the object in the section. The method also selects a velocity from the potential velocities for the object in the section using a potential velocity in the potential velocities having a highest signal-to-noise ratio in the signal-to-noise ratios.

  20. Exotic objects of atomic physics

    Science.gov (United States)

    Eletskii, A. V.

    2017-11-01

    There has been presented a short survey of physical properties, methods of production and exploration as well as directions of practical usage of the objects of atomic physics which are not yet described in detail in modern textbooks and manuals intended for students of technical universities. The family of these objects includes negative and multicharged ions, Rydberg atoms, excimer molecules, clusters. Besides of that, in recent decades this family was supplemented with new nanocarbon structures such as fullerenes, carbon nanotubes and graphene. The textbook “Exotic objects of atomic physics” [1] edited recently contains some information on the above-listed objects of the atomic physics. This textbook can be considered as a supplement to classic courses of atomic physics teaching in technical universities.

  1. Precise object tracking under deformation

    International Nuclear Information System (INIS)

    Saad, M.H

    2010-01-01

    The precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This frame-work focuses on the precise object tracking under deformation such as scaling , rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high precession results.

  2. First-Class Object Sets

    DEFF Research Database (Denmark)

    Ernst, Erik

    2009-01-01

    Typically, an object is a monolithic entity with a fixed interface.  To increase flexibility in this area, this paper presents first-class object sets as a language construct.  An object set offers an interface which is a disjoint union of the interfaces of its member objects.  It may also be use...... to a mainstream virtual machine in order to improve on the support for family polymorphism.  The approach is made precise by means of a small calculus, and the soundness of its type system has been shown by a mechanically checked proof in Coq....

  3. Superluminal motion of extragalactic objects

    Energy Technology Data Exchange (ETDEWEB)

    Matveenko, L.I. (AN SSSR, Moscow. Inst. Kosmicheskikh Issledovanij)

    1983-07-01

    Extragalactic objects with active nuclei are reviewed. Experimental data are obtained with the method of superfar radiointerferometry. The main peculiarities of the complex structure of Seyfert galaxies, quasars and lacertae objects are considered: the distribution of radiobrightness, spectra, alteration of the density of radiation flux and the distance between the components of sources. The superluminal velocities of component divergence observed are explained by different reasons: fast motion of components considerable difference of the Hubble component or non-cosmologic nature of the red shift of objects, effect of echoreflection of radiation, gravitation lens, systematic alteration of the optical thickness of the object, synchronouys radiation of electrons in the dipole magnetic field, as well as different kinematic illusions connected with the final time of signal propagation.

  4. Command in the Objective Force

    National Research Council Canada - National Science Library

    Wilbeck, Christopher

    2003-01-01

    This paper seeks to answer what type of command will best serve the Army's Objective Force in gaining the initiative, building momentum, and exploiting success to achieve land dominance in the future...

  5. Stream Clustering of Growing Objects

    Science.gov (United States)

    Siddiqui, Zaigham Faraz; Spiliopoulou, Myra

    We study incremental clustering of objects that grow and accumulate over time. The objects come from a multi-table stream e.g. streams of Customer and Transaction. As the Transactions stream accumulates, the Customers’ profiles grow. First, we use an incremental propositionalisation to convert the multi-table stream into a single-table stream upon which we apply clustering. For this purpose, we develop an online version of K-Means algorithm that can handle these swelling objects and any new objects that arrive. The algorithm also monitors the quality of the model and performs re-clustering when it deteriorates. We evaluate our method on the PKDD Challenge 1999 dataset.

  6. 从游客环境容量到LAC理论环境容量概念的新发展%From Recreation Carrying Capacity to LAC Theory--On the New Development of Environmental Capacity Concept

    Institute of Scientific and Technical Information of China (English)

    杨锐

    2003-01-01

    LAC(可接受的改变极限)是从游客环境容量概念发展而来的,用于解决资源保护和旅游发展之间矛盾的理论.这一理论在很多国家的规划和管理中得到了广泛的应用,取得了良好的效果.本文阐述了从环境容量到LAC理论的发展过程,描述了LAC理论的九个步骤,简要介绍了LAC理论的衍生技术方法.

  7. Diseases of captive yellow seahorse Hippocampus kuda Bleeker, pot-bellied seahorse Hippocampus abdominalis Lesson and weedy seadragon Phyllopteryx taeniolatus (Lacépède).

    Science.gov (United States)

    LePage, V; Young, J; Dutton, C J; Crawshaw, G; Paré, J A; Kummrow, M; McLelland, D J; Huber, P; Young, K; Russell, S; Al-Hussinee, L; Lumsden, J S

    2015-05-01

    Seahorses, pipefish and seadragons are fish of the Family Syngnathidae. From 1998 to 2010, 172 syngnathid cases from the Toronto Zoo were submitted for post-mortem diagnostics and retrospectively examined. Among the submitted species were yellow seahorses Hippocampus kuda Bleeker (n=133), pot-bellied seahorses Hippocampus abdominalis Lesson (n=35) and weedy seadragons Phyllopteryx taeniolatus (Lacépède; n=4). The three most common causes of morbidity and mortality in this population were bacterial dermatitis, bilaterally symmetrical myopathy and mycobacteriosis, accounting for 24%, 17% and 15% of cases, respectively. Inflammatory processes were the most common diagnoses, present in 117 cases. Seven neoplasms were diagnosed, environmental aetiologies were identified in 46 cases, and two congenital defects were identified. © 2014 John Wiley & Sons Ltd.

  8. Precise Object Tracking under Deformation

    International Nuclear Information System (INIS)

    Saad, M.H.

    2010-01-01

    The precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This framework focuses on the precise object tracking under deformation such as scaling, rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high precession results. xiiiThe precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This framework focuses on the precise object tracking under deformation such as scaling, rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high

  9. Well-Being and Objectivity

    Directory of Open Access Journals (Sweden)

    Jakub Bożydar Wiśniewski

    2011-03-01

    Full Text Available In this paper, I investigate the issue of whether there exists an objective element of well-being, completely independent of anyone’s desires, interests and preferences. After rejecting health-based and convention-based approaches to objectivity, I conclude that the element in question consists in respecting autonomy, voluntariness of every purposive agent and the principle of non-aggression.

  10. Louisiana SIP: LAC 33:III Ch. 14 Subchap B, 1431 to 1434--Conformity to State or Federal Implementation Plans of Transportation Plans, Programs, and Projects Developed, Funded, or Approved Under Title 23 U.S.C. or the Federal Transit Laws

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch. 14 Subchap B, 1431 to 1434--Conformity to State or Federal Implementation Plans of Transportation Plans, Programs, and Projects Developed, Funded, or Approved Under Title 23 U.S.C. or the Federal Transit Laws

  11. Louisiana SIP: LAC 33:III Ch 2132. Stage II Vapor Recovery Systems for Control of Vehicle Refuelling Emissions at Gasoline Dispensing Facilities; SIP effective 2011-08-04 (LAd34) and 2016-02-29 (LAd47) to 2017-09-27

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch 2132. Stage II Vapor Recovery Systems for Control of Vehicle Refuelling Emissions at Gasoline Dispensing Facilities; SIP effective 2011-08-04 (LAd34) and 2016-02-29 (LAd47) to 2017-09-27

  12. Endogenous IL-33 is highly expressed in mouse epithelial barrier tissues, lymphoid organs, brain, embryos, and inflamed tissues: in situ analysis using a novel Il-33-LacZ gene trap reporter strain.

    Science.gov (United States)

    Pichery, Mélanie; Mirey, Emilie; Mercier, Pascale; Lefrancais, Emma; Dujardin, Arnaud; Ortega, Nathalie; Girard, Jean-Philippe

    2012-04-01

    IL-33 (previously known as NF from high endothelial venules) is an IL-1 family cytokine that signals through the ST2 receptor and drives cytokine production in mast cells, basophils, eosinophils, invariant NKT and NK cells, Th2 lymphocytes, and type 2 innate immune cells (natural helper cells, nuocytes, and innate helper 2 cells). Little is known about endogenous IL-33; for instance, the cellular sources of IL-33 in mouse tissues have not yet been defined. In this study, we generated an Il-33-LacZ gene trap reporter strain (Il-33(Gt/Gt)) and used this novel tool to analyze expression of endogenous IL-33 in vivo. We found that the Il-33 promoter exhibits constitutive activity in mouse lymphoid organs, epithelial barrier tissues, brain, and embryos. Immunostaining with anti-IL-33 Abs, using Il-33(Gt/Gt) (Il-33-deficient) mice as control, revealed that endogenous IL-33 protein is highly expressed in mouse epithelial barrier tissues, including stratified squamous epithelia from vagina and skin, as well as cuboidal epithelium from lung, stomach, and salivary gland. Constitutive expression of IL-33 was not detected in blood vessels, revealing the existence of species-specific differences between humans and mice. Importantly, IL-33 protein was always localized in the nucleus of producing cells with no evidence for cytoplasmic localization. Finally, strong expression of the Il-33-LacZ reporter was also observed in inflamed tissues, in the liver during LPS-induced endotoxin shock, and in the lung alveoli during papain-induced allergic airway inflammation. Together, our findings support the possibility that IL-33 may function as a nuclear alarmin to alert the innate immune system after injury or infection in epithelial barrier tissues.

  13. Testing Object-Oriented Software

    DEFF Research Database (Denmark)

    Caspersen, Michael Edelgaard; Madsen, Ole Lehrmann; Skov, Stefan H.

    The report is a result of an activity within the project Centre for Object Technology (COT), case 2. In case 2 a number of pilot projects have been carried out to test the feasibility of using object technology within embedded software. Some of the pilot projects have resulted in proto-types that......The report is a result of an activity within the project Centre for Object Technology (COT), case 2. In case 2 a number of pilot projects have been carried out to test the feasibility of using object technology within embedded software. Some of the pilot projects have resulted in proto......-types that are currently being developed into production versions. To assure a high quality in the product it was decided to carry out an activ-ity regarding issues in testing OO software. The purpose of this report is to discuss the issues of testing object-oriented software. It is often claimed that testing of OO...... software is radically different form testing traditional software developed using imperative/procedural programming. Other authors claim that there is no difference. In this report we will attempt to give an answer to these questions (or at least initiate a discussion)....

  14. Object Pragmatics and Language Development.

    Science.gov (United States)

    Béguin, Marie

    2016-12-01

    The purpose of this contribution is to investigate the advent of language in the light of the appropriation of the cultural uses of the material objects related to material culture and the constitution of their public and shared meanings linked to their uses. First, we suggest that the Object Pragmatics paradigm offers a framework which allows us to take into account the uses of objects in daily life as a site of social conventions, communication and public and shared meanings. Second, we would like to underline the key role of the adult's mediations in the child's ability to evolve towards linguistic development. This contribution will discuss the notion of scenario involving primarily the object, as a possible semiotic tool to support the child's transition to language. We will finally illustrate that it is possible to take into consideration the mastery of conventional uses of the object in the child's ability to engage in a scenario and then to move towards communication and speech development. These issues will be addressed in the context of a research project which focuses on the observation of children interacting with an adult at 16, 20 and 24 months. These longitudinal data were collected by video in a semi-experimental triadic interaction design. The triadic interaction is considered as a relevant unit for the observation and analysis of the role of material culture in speech development, suggesting the existence of new mechanisms to be taken into account in addition to the interactive conditions largely mentioned in literature.

  15. Object technology: A white paper

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, S.R.; Arrowood, L.F.; Cain, W.D.; Stephens, W.M.; Vickers, B.D.

    1992-05-11

    Object-Oriented Technology (OOT), although not a new paradigm, has recently been prominently featured in the trade press and even general business publications. Indeed, the promises of object technology are alluring: the ability to handle complex design and engineering information through the full manufacturing production life cycle or to manipulate multimedia information, and the ability to improve programmer productivity in creating and maintaining high quality software. Groups at a number of the DOE facilities have been exploring the use of object technology for engineering, business, and other applications. In this white paper, the technology is explored thoroughly and compared with previous means of developing software and storing databases of information. Several specific projects within the DOE Complex are described, and the state of the commercial marketplace is indicated.

  16. Exploring object-oriented technologies

    CERN Multimedia

    2000-01-01

    Object oriented technologies are the corner stone of modern software development. A piece of software is today conceived, constructed and tested as a set of objects interacting with each other, rather than as a large sequential program. OO is present throughout the whole software life cycle allowing for maintainable code re-use, clean design and manageable complexity. OO is also the seed upon which other technologies are being built and deployed, such as distributed computing, component models, open interoperability, etc.This series of three seminars will provide a pragmatic overview on the main ideas behind OO software development and will explain the inner workings of the most outstanding technologies being built on OO, such as UML, CORBA, Component Models, Agent Oriented Computing, Business Objects, etc.

  17. Acoustic Characterization of Mesoscale Objects

    Energy Technology Data Exchange (ETDEWEB)

    Chinn, D; Huber, R; Chambers, D; Cole, G; Balogun, O; Spicer, J; Murray, T

    2007-03-13

    This report describes the science and engineering performed to provide state-of-the-art acoustic capabilities for nondestructively characterizing mesoscale (millimeter-sized) objects--allowing micrometer resolution over the objects entire volume. Materials and structures used in mesoscale objects necessitate the use of (1) GHz acoustic frequencies and (2) non-contacting laser generation and detection of acoustic waves. This effort demonstrated that acoustic methods at gigahertz frequencies have the necessary penetration depth and spatial resolution to effectively detect density discontinuities, gaps, and delaminations. A prototype laser-based ultrasonic system was designed and built. The system uses a micro-chip laser for excitation of broadband ultrasonic waves with frequency components reaching 1.0 GHz, and a path-stabilized Michelson interferometer for detection. The proof-of-concept for mesoscale characterization is demonstrated by imaging a micro-fabricated etched pattern in a 70 {micro}m thick silicon wafer.

  18. Superluminal motion of extragalactic objects

    International Nuclear Information System (INIS)

    Matveenko, L.I.

    1983-01-01

    Extragalactic objects with active nuclei are reviewed. Experimental data are obtained with the method of superfar radiointerferometry. The main peculiarities of the complex strUcture of Seyfert galaxies quasars and lacertae ob ects are considered: the distribution of radiobrightness, spectra, alteration of the density of radiation flux and the distance between the components of sources. The superluminal velocities of component divergence observed are explained by different reasons: fast motion of components considerable difference of the Hubble component or non-cosmologic nature of the red shift of objects, effect of echoreflection of radiation, gravitation lens, systematic alteration of the optical thickness of the object, synchronoUs radiation of electrons in the dipole magnetic field, as well as different kinematic illusions connected with the final time of signal propagation

  19. Elaborazione didattica di Learning Objects.

    Directory of Open Access Journals (Sweden)

    Luigi Guerra

    2006-01-01

    Full Text Available L’idea di un modello didattico problematico per la realizzazione di Learning Objects riprende i temi del problematicismo pedagogico e si impegna a definire un’ipotesi formativa complessa capace di valorizzare la possibile positiva compresenza integrata di strategie didattiche diverse (finanche antitetiche ma componibili in una logica appunto di matrice problematicista. Il punto di partenza del modello proposto è rappresentato dalla opportunità di definire tre tipologie fondamentali di Learning Objects, rispettivamente centrati sull’oggetto, sul processo e sul soggetto dell’apprendimento.

  20. TACTILE SENSING FOR OBJECT IDENTIFICATION

    DEFF Research Database (Denmark)

    Drimus, Alin; Marian, Nicolae; Bilberg, Arne

    2009-01-01

    The artificial sense of touch is a research area that can be considered still in demand, compared with the human dexterity of grasping a wide variety of shapes and sizes, perform complex tasks, and switch between grasps in response to changing task requirements. For handling unknown objects...... in unstructured environments, tactile sensing can provide more than valuable to complementary vision information about mechanical properties such as recognition and characterization, force, pressure, torque, compliance, friction, and mass as well as object shape, texture, position and pose. In this paper, we...

  1. Object oriented JavaScript

    CERN Document Server

    Stefanov, Stoyan

    2013-01-01

    You will first be introduced to object-oriented programming, then to the basics of objects in JavaScript. This book takes a do-it-yourself approach when it comes to writing code, because the best way to really learn a programming language is by writing code. You are encouraged to type code into Firebug's console, see how it works and then tweak it and play around with it. There are practice questions at the end of each chapter to help you review what you have learned.For new to intermediate JavaScript developer who wants to prepare themselves for web development problems solved by smart JavaSc

  2. Object-Oriented Type Inference

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Palsberg, Jens

    1991-01-01

    We present a new approach to inferring types in untyped object-oriented programs with inheritance, assignments, and late binding. It guarantees that all messages are understood, annotates the program with type information, allows polymorphic methods, and can be used as the basis of an op...

  3. Interaction between beans and objects

    International Nuclear Information System (INIS)

    Farias, J.T.

    1988-01-01

    The interaction between the X-ray beans and objects are studied, with the modification in the intensity. The kilovolt, the bundle filtration, the structure and composition of the patient and the quantity of scattered radiation are also described, as the main parameters for the contrast and for the dose of the patient. (C.G.C.) [pt

  4. Photogrammetric Measurements of Heritage Objects

    Science.gov (United States)

    Tumeliene, E.; Nareiko, V.; Suziedelyte Visockiene, J.

    2017-12-01

    Cultural heritage is an invaluable example of human culture and creativity. The majority of them can become unstable or can be destroyed due to a combination of human and natural disturbances. In order to restore, preserve, and systematize data about architectural heritage objects, it is necessary to have geodetic, photogrammetric measurements of such data and to constantly monitor condition of the objects. The data of immovable cultural objects for many years are stored in photogrammetric data archives. Such archives have Germany, Lithuania, England and other countries. The article gives a brief introduction of the history of data archives formation and presents a photogrammetric and modern methods of modelling the spatial geometric properties of objects currently used to reveal immovable cultural properties and to evaluate geometric sizes. The pilot work was done with the Concept Capture simulation program that was developed by the Bentley company with photos of the Blessed Virgin Mary painting in Pivašiūnai of Trakai district. A shot from the ground with 12.4 MP resolution Pentax K-x camera was done using lenses with different focal lengths. The painting of the Blessed Virgin Mary is coordinated by 4 reference geodesic points and therefore after the modelling work it was possible to evaluate the accuracy of the created model. Based on the results of the spatial (3D) model, photo shooting and modelling recommendations are presented, the advantages of the new technology are distinguished.

  5. Michael Beitz: Objects of Communication

    Science.gov (United States)

    Hoefferle, Mary

    2014-01-01

    For this Instructional Resource, the author interviewed contemporary sculptor Michael Beitz, who uses art to explore the role of designed objects in human communication and emotional experience. This column was written in response to calls for using Enduring Understandings/Big Ideas (National Coalition for Core Arts Standards, 2013; Stewart &…

  6. Managed Objects for Infrastructure Data

    DEFF Research Database (Denmark)

    Kjems, Erik; Bodum, Lars; Kolar, Jan

    2009-01-01

    Using data objects to describe features in the real world is a new idea and several approaches have already been shown to match scientific paradigms exceedingly well. Depending on the required level of abstraction, it is possible to represent the world more or less close to reality. In the realm ...

  7. Subjectivity, objectivity, and triangular space.

    Science.gov (United States)

    Britton, Ronald

    2004-01-01

    The author reviews his ideas on subjectivity, objectivity, and the third position in the psychoanalytic encounter, particularly in clinical work with borderline and narcissistic patients. Using the theories of Melanie Klein and Wilfred Bion as a basis, the author describes his concept of triangular space. A case presentation of a particular type of narcissistic patient illustrates the principles discussed.

  8. Quantitative Nuclear Cardiology: How objective?

    International Nuclear Information System (INIS)

    Crawley, J.C.W.; Raval, U.; Soman, P.; Lahiri, A.

    1997-01-01

    The object of this study was to establish the accuracy required from the operator in indicating the centre and axis the left ventricle, and in placing regions of interest (ROIs), whilst using the MYO TOMO and MYO QUANT software to analyze tomographic data from nuclear cardiology

  9. Teachers' Careers: The Objective Dimension.

    Science.gov (United States)

    Evetts, Julia

    1986-01-01

    Analyzes the objective dimension of teachers' careers showing how 530 British male/female teachers are distributed throughout the pay scale and promotions making up the formal structure of teaching. Indicates length of experience is the rewarding but not the sole factor in bureaucratic structure and differential male/female career achievements.…

  10. Compact objects and accretion disks

    NARCIS (Netherlands)

    Blandford, Roger; Agol, Eric; Broderick, Avery; Heyl, Jeremy; Koopmans, Leon; Lee, Hee-Won

    2002-01-01

    Recent developments in the spectropolarimetric study of compact objects, specifically black holes (stellar and massive) and neutron stars are reviewed. The lectures are organized around five topics: disks, jets, outflows, neutron stars and black holes. They emphasize physical mechanisms and are

  11. The Objective of Financial Reporting.

    Science.gov (United States)

    Schermann, Kenneth R.

    1986-01-01

    Alerts public school business officials to a financial reporting concepts statement to be issued by the Governmental Accounting Standards Board in late 1986. The new directive will outline four objectives concerned with accountability procedures, resource management and compliance information, operating results, and future financial capabilities.…

  12. Objective consensus from decision trees

    International Nuclear Information System (INIS)

    Putora, Paul Martin; Panje, Cedric M; Papachristofilou, Alexandros; Pra, Alan Dal; Hundsberger, Thomas; Plasswilm, Ludwig

    2014-01-01

    Consensus-based approaches provide an alternative to evidence-based decision making, especially in situations where high-level evidence is limited. Our aim was to demonstrate a novel source of information, objective consensus based on recommendations in decision tree format from multiple sources. Based on nine sample recommendations in decision tree format a representative analysis was performed. The most common (mode) recommendations for each eventuality (each permutation of parameters) were determined. The same procedure was applied to real clinical recommendations for primary radiotherapy for prostate cancer. Data was collected from 16 radiation oncology centres, converted into decision tree format and analyzed in order to determine the objective consensus. Based on information from multiple sources in decision tree format, treatment recommendations can be assessed for every parameter combination. An objective consensus can be determined by means of mode recommendations without compromise or confrontation among the parties. In the clinical example involving prostate cancer therapy, three parameters were used with two cut-off values each (Gleason score, PSA, T-stage) resulting in a total of 27 possible combinations per decision tree. Despite significant variations among the recommendations, a mode recommendation could be found for specific combinations of parameters. Recommendations represented as decision trees can serve as a basis for objective consensus among multiple parties

  13. Objective techniques for psychological assessment

    Science.gov (United States)

    Wortz, E.; Hendrickson, W.; Ross, T.

    1973-01-01

    A literature review and a pilot study are used to develop psychological assessment techniques for determining objectively the major aspects of the psychological state of an astronaut. Relationships between various performance and psychophysiological variables and between those aspects of attention necessary to engage successfully in various functions are considered in developing a paradigm to be used for collecting data in manned isolation chamber experiments.

  14. Fast and Objective MRTD measurement

    NARCIS (Netherlands)

    Jong, A.N. de; Bakker, S.J.M.

    1988-01-01

    Manufacturers and Users of the Thermal Imagers have spent very much time upon the definition and measurement of the generally accepted performance curve: MRTD (Minimum Resolvable Temperature Difference). The need for a cheap and fast, objective measurement method has considerably increased since the

  15. Objective consensus from decision trees.

    Science.gov (United States)

    Putora, Paul Martin; Panje, Cedric M; Papachristofilou, Alexandros; Dal Pra, Alan; Hundsberger, Thomas; Plasswilm, Ludwig

    2014-12-05

    Consensus-based approaches provide an alternative to evidence-based decision making, especially in situations where high-level evidence is limited. Our aim was to demonstrate a novel source of information, objective consensus based on recommendations in decision tree format from multiple sources. Based on nine sample recommendations in decision tree format a representative analysis was performed. The most common (mode) recommendations for each eventuality (each permutation of parameters) were determined. The same procedure was applied to real clinical recommendations for primary radiotherapy for prostate cancer. Data was collected from 16 radiation oncology centres, converted into decision tree format and analyzed in order to determine the objective consensus. Based on information from multiple sources in decision tree format, treatment recommendations can be assessed for every parameter combination. An objective consensus can be determined by means of mode recommendations without compromise or confrontation among the parties. In the clinical example involving prostate cancer therapy, three parameters were used with two cut-off values each (Gleason score, PSA, T-stage) resulting in a total of 27 possible combinations per decision tree. Despite significant variations among the recommendations, a mode recommendation could be found for specific combinations of parameters. Recommendations represented as decision trees can serve as a basis for objective consensus among multiple parties.

  16. How Medical Students Use Objectives.

    Science.gov (United States)

    Mast, Terrill A.; And Others

    Two related studies were undertaken at Southern Illinois University on how students in the School of Medicine use the instructional objectives faculty prepare for them. Students in the classes of 1978 and 1979 were surveyed in their final month of training. The second survey was modified, based on responses from the first. The five research…

  17. 'Shelter' object safety. Structural aspects

    International Nuclear Information System (INIS)

    Krivosheev, P.I.; Nemchinov, Yu.I.; Bambura, A.N.; Sokolov, A.P.; Shenderovich, V.Ya.; Vasyagin, R.V.; Klyuchnikov, A.A.; Shcherbin, V.N.; Rud'ko, V.M.; Tokarevskij, V.V.; Belousov, E.L.; Khejger, D.; Gorodetskij, L.

    2001-01-01

    In 1997 the group of the international experts including Ukrainian organizations and 'Shelter' Object ChNPP are developed the plan of SO transformation into ecological safe status (plan SIP). The realization of the plan was carried out on basis of international tender. The results of structural aspects of SO safety and it transformation into ecological safe state (ESS) are resented in this report

  18. Recurrent processing during object recognition

    Directory of Open Access Journals (Sweden)

    Randall C. O'Reilly

    2013-04-01

    Full Text Available How does the brain learn to recognize objects visually, and perform this difficult feat robustly in the face of many sources of ambiguity and variability? We present a computational model based on the biology of the relevant visual pathways that learns to reliably recognize 100 different object categories in the face of of naturally-occurring variability in location, rotation, size, and lighting. The model exhibits robustness to highly ambiguous, partially occluded inputs. Both the unified, biologically plausible learning mechanism and the robustness to occlusion derive from the role that recurrent connectivity and recurrent processing mechanisms play in the model. Furthermore, this interaction of recurrent connectivity and learning predicts that high-level visual representations should be shaped by error signals from nearby, associated brain areas over the course of visual learning. Consistent with this prediction, we show how semantic knowledge about object categories changes the nature of their learned visual representations, as well as how this representational shift supports the mapping between perceptual and conceptual knowledge. Altogether, these findings support the potential importance of ongoing recurrent processing throughout the brain's visual system and suggest ways in which object recognition can be understood in terms of interactions within and between processes over time.

  19. Design of object processing systems

    NARCIS (Netherlands)

    Grigoras, D.R.; Hoede, C.

    Object processing systems are met rather often in every day life, in industry, tourism, commerce, etc. When designing such a system, many problems can be posed and considered, depending on the scope and purpose of design. We give here a general approach which involves graph theory, and which can

  20. ANNOTATION SUPPORTED OCCLUDED OBJECT TRACKING

    Directory of Open Access Journals (Sweden)

    Devinder Kumar

    2012-08-01

    Full Text Available Tracking occluded objects at different depths has become as extremely important component of study for any video sequence having wide applications in object tracking, scene recognition, coding, editing the videos and mosaicking. The paper studies the ability of annotation to track the occluded object based on pyramids with variation in depth further establishing a threshold at which the ability of the system to track the occluded object fails. Image annotation is applied on 3 similar video sequences varying in depth. In the experiment, one bike occludes the other at a depth of 60cm, 80cm and 100cm respectively. Another experiment is performed on tracking humans with similar depth to authenticate the results. The paper also computes the frame by frame error incurred by the system, supported by detailed simulations. This system can be effectively used to analyze the error in motion tracking and further correcting the error leading to flawless tracking. This can be of great interest to computer scientists while designing surveillance systems etc.