Problems Concerning E. E. C. and E. F. T. A.

Meyer, F. V.; Patriarca, G.

doi:10.2307/2228600

Cited by 5 publications

(9 citation statements)

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“…These arguments for velocity structures in the jets of TeV HBLs are consistent with recent developments in radio-loud AGN unification [25,26]. In this unification work, radio-loud AGN are divided into two distinct subpopulations that constitute a 'broken power sequence'.…”

Section: -P2supporting

confidence: 81%

The Parsec-Scale Structure of the Newer TeV Blazars

Piner

Edwards

2013

EPJ Web of Conferences

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Abstract. We expand our previous studies of the parsec-scale structure of TeV blazars by presenting firstepoch images from VLBA monitoring of ten newer TeV HBLs. All ten sources were successfully detected and imaged, and all showed a one-sided core-jet structure. Many display a morphology common to TeV HBLs: a short, collimated jet followed by a transition to low surface brightness extended emission with a much broader opening angle. The newly detected TeV HBLs tend to be fainter in the radio; the median core flux density was 22 mJy, and the median brightness temperature was 8 × 10 9 K. The brightness temperatures are well below the equipartition limit, and thus the VLBI cores do not require strong beaming, consistent with the modest values of Doppler and Lorentz factors found in the VLBI jets of TeV HBLs by other studies, and contrasting with the strong beaming generally required by the TeV emission. We study the full sample of TeV HBLs that have been observed with VLBI, and find a correlation between TeV flux and VLBI core brightness temperature, suggesting different but correlated beaming factors for the TeV and radio emission. We present a discussion of these observations in the context of velocity structures in the jets of the TeV HBLs.

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Section: -P2supporting

confidence: 81%

The Parsec-Scale Structure of the Newer TeV Blazars

Piner

Edwards

2013

EPJ Web of Conferences

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“…We have examined this issue with respect to two organisms. R. salexigens and C. salexigens contain a single cross-reacting protein (Table 1), and PYPs have been isolated from them (18,19). Flash photolysis experiments have indicated that both proteins have a photocycle very similar to that observed for PYP from E. halophila (7,19).…”

Section: Resultsmentioning

confidence: 90%

“…Evidence indicating that the protein functions as the photoreceptor in a negative phototactic response has been obtained (28). Despite the photochemical and functional similarities between the photoactive yellow protein (PYP) and the sensory rhodopsins, the chromophoric group in PYP is not retinal (33).Recently, PYPs were purified from Rhodospirillum salexigens (19) and Chromatium salexigens (18). Therefore, PYP is now known to be present in halophilic representatives of three * Corresponding author.…”

mentioning

confidence: 99%

“…Recently, PYPs were purified from Rhodospirillum salexigens (19) and Chromatium salexigens (18). Therefore, PYP is now known to be present in halophilic representatives of three * Corresponding author.…”

mentioning

confidence: 99%

“…Recently, PYPs were purified from Rhodospirillum salexigens (19) and Chromatium salexigens (18). Therefore purple phototrophic bacterial families.…”

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confidence: 99%

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The photoactive yellow protein from Ectothiorhodospira halophila as studied with a highly specific polyclonal antiserum: (intra)cellular localization, regulation of expression, and taxonomic distribution of cross-reacting proteins

et al. 1994

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A rabbit antiserum was raised against the photoactive yellow protein (PYP) from Ectothiorhodospira halophila and purified by adsorption experiments to obtain a highly specific polyclonal antiserum. This antiserum was used to obtain the following results. (i) In E. halophila, PYP can be isolated from the fraction of soluble proteins. In the intact cell, however, PYP appeared to be associated with (intra)cytoplasmic membranes, as was concluded from analysis of immunogold-labelled thin sections of the organism. (ii) The regulation of expression of PYP was studied by using dot blot assays, Western blotting (immunoblotting), and rocket immunoelectrophoresis. Under all conditions investigated (light color, salt concentration, and growth phase), PYP was expressed constitutively in E. halophila. However, when Rhodospirillum salexigens was grown aerobically, the expression of PYP was suppressed. (iii) A large number of prokaryotic microorganisms contained a single protein, with an apparent size of approximately 15 kDa, that cross-reacted with the antiserum. Among the positively reacting organisms were both phototrophic and chemotrophic, as well as motile and nonmotile, organisms. After separation of cellular proteins into a membrane fraction and soluble proteins, it was established that organisms adapted to growth at higher salt concentrations tended to have the cross-reacting protein in the soluble fraction. In the cases of R. salegens and Chromatium salexigens, we have shown that the cross-reacting protein involved is strongly homologous to PYP from E. halophila.Membrane-bound photoactive proteins are known to function in Halobacterium halobium. In this organism and in related bacteria, retinal-containing proteins have a role in light energy transduction and in phototactic responses (for reviews, see references 29 and 31). A few years ago, the presence of a water-soluble protein of 14 kDa with a distinct yellow color was described in the purple sulfur eubacterium Ectothiorhodospira halophila (15). This protein is photoactive: it displays a photocycle that is quite similar to the photocycle of the sensory rhodopsins (10,20,22,23). Its three-dimensional structure, which is unrelated to the structure of the bacterial rhodopsins, has been elucidated at 2.4-A (0.24-nm) resolution (14). It consists of two perpendicular plates of A sheet, forming a ,3-clam structure, also observed in a number of eukaryotic proteins. Evidence indicating that the protein functions as the photoreceptor in a negative phototactic response has been obtained (28). Despite the photochemical and functional similarities between the photoactive yellow protein (PYP) and the sensory rhodopsins, the chromophoric group in PYP is not retinal (33).Recently, PYPs were purified from Rhodospirillum salexigens (19) and Chromatium salexigens (18). Therefore, PYP is now known to be present in halophilic representatives of three * Corresponding author. Mailing address:

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p‐Type and n‐Type Behavior of Chromium Oxide as a Function of the Applied Potential

Metikoš‐Huković

Ceraj-Cerić

1987

J. Electrochem. Soc.

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Thermodynamic data as well as physical and electrochemical studies demonstrate that the composition of the passive layer on chromium depends on the potential and the electrolyte pH. The electrochemical properties of Cr203 electrodes were compared with the anodic behavior of chromium in borate buffer solutions. The feasibility of the solid-phase transformation of a surface layer under anodic polarization was investigated. The conductivity type and deviation from the stoichiometric composition of the chromium oxide was determined in situ using the photopolarization method. Depending

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Problems Concerning E. E. C. and E. F. T. A.

Cited by 5 publications

References 0 publications

The Parsec-Scale Structure of the Newer TeV Blazars

The Parsec-Scale Structure of the Newer TeV Blazars

The photoactive yellow protein from Ectothiorhodospira halophila as studied with a highly specific polyclonal antiserum: (intra)cellular localization, regulation of expression, and taxonomic distribution of cross-reacting proteins

p‐Type and n‐Type Behavior of Chromium Oxide as a Function of the Applied Potential

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