The small dispersion of the mid IR -- hard X-ray correlation in AGN

Context: We investigate mid-infrared and X-ray properties of the dusty torus in unification scenarios for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain AGN unification scenarios. Methods: With VISIR at the VLT, we have obtained the currently highest angular resolution (0".35 FWHM) narrow-band mid infrared images of the nuclei of 8 nearby Seyfert galaxies. Combining these observations with X-ray data from the literature we study the correlation between their mid IR and hard X-ray luminosities. Results: We find that the rest frame 12.3 mircon (L_MIR) and 2-10 keV (L_X) luminosities are correlated at a highly significant level. The best fit power-law to our data is log L_MIR \propto (1.60 \pm 0.22) log L_X, showing a much smaller dispersion than earlier studies. Conclusions: The similarity in the og L_MIR / log L_X ratio between Sy1s and Sy2s even using high angular resolution MIR data implies that the similarity is intrinsic to AGN and not caused by contamination from extra-nuclear emission. This supports clumpy torus models. The exponent of the correlation constrains the inner geometry of the torus.Comment: 5 pages, 3 figures, accepted for publication in Astronomy & Astrophysic

Dust tori in radio galaxies

We investigate the validity of the quasar - radio galaxy unification scenario and detect dust tori within radio galaxies of various types. Using VISIR on the VLT, we acquired sub-arcsecond (~0.40") resolution N-band images, at a wavelength of 11.85 micron, of the nuclei of a sample of 27 radio galaxies of four types in the redshift range z=0.006-0.156. The sample consists of 8 edge-darkened, low-power Fanaroff-Riley class I (FR-I) radio galaxies, 6 edge-brightened, class II (FR-II) radio galaxies displaying low-excitation optical emission, 7 FR-IIs displaying high-excitation optical emission, and 6 FR-II broad emission line radio galaxies. Out of the sample of 27 objects, 10 nuclei are detected and several have constraining non-detections at sensitivities of 7 mJy, the limiting flux a point source has when detected with a signal-to-noise ratio of 10 in one hour of source integration. On the basis of the core spectral energy distributions of this sample we find clear indications that many FR-I and several low-excitation FR-II radio galaxies do not contain warm dust tori. At least 57+-19 percent of the high-excitation FR-IIs and almost all broad line radio galaxies display excess infrared emission, which must be attributed to warm dust reradiating accretion activity. The FR-I and low-excitation FR-II galaxies all possess low efficiencies, calculated as the ratio of bolometric and Eddington luminosity log (L_bol/L_Edd) < -3. This suggests that thick tori are absent at low accretion rates and/or low efficiencies. We argue that the unification viewing angle range 0-45 degrees of quasars should be increased to ~60 degrees, at least at lower luminosities.Comment: 17 pages, 9 figures, published in Astronomy and Astrophysics. Version 2 matches published version

FoxO1 is involved in the antineoplastic effect of calorie restriction.

The FoxO transcription factors may be involved in the antiaging effect of calorie restriction (CR) in mammals. To test the hypothesis, we used FoxO1 knockout heterozygotic (HT) mice, in which the FoxO1 mRNA level was reduced by 50%, or less, of that in wild-type (WT) mouse tissues. The WT and HT mice were fed ad libitum (AL) or 30% CR diets from 12 weeks of age. Aging- and CR-related changes in body weight, food intake, blood glucose, and insulin concentrations were similar between the WT and HT mice in the lifespan study. The response to oxidative stress, induced by intraperitoneal injection of 3-nitropropionic acid (3-NPA), was evaluated in the liver and hippocampus at 6 months of age. Several of the selected FoxO1-target genes for cell cycle arrest, DNA repair, apoptosis, and stress resistance were up-regulated in the WT-CR tissues after 3-NPA injection, while the effect was mostly diminished in the HT-CR tissues. Of these gene products, we focused on the nuclear p21 protein level in the liver and confirmed its up-regulation only in the WT-CR mice in response to oxidative stress. The lifespan did not differ significantly between the WT and HT mice in AL or CR conditions. However, the antineoplastic effect of CR, as indicated by reduced incidence of tumors at death in the WT-CR mice, was mostly abrogated in the HT-CR mice. The present results suggest a role for FoxO1 in the antineoplastic effect of CR through the induction of genes responsible for protection against oxidative and genotoxic stress

The peculiar radio galaxy 4C 35.06: a case for recurrent AGN activity?

Using observations obtained with the LOw Fequency ARray (LOFAR), the Westerbork Synthesis Radio Telescope (WSRT) and archival Very Large Array (VLA) data, we have traced the radio emission to large scales in the complex source 4C 35.06 located in the core of the galaxy cluster Abell 407. At higher spatial resolution (~ 4″), the source was known to have two inner radio lobes spanning 31 kpc and a diffuse, low-brightness extension running parallel to them, offset by about 11 kpc (in projection). At 62 MHz, we detect the radio emission of this structure extending out to 210 kpc. At 1.4 GHz and intermediate spatial resolution (~ 30″), the structure appears to have a helical morphology. We have derived the characteristics of the radio spectral index across the source. We show that the source morphology is most likely the result of at least two episodes of AGN activity separated by a dormant period of around 35 Myr. The outermost regions of radio emission have a steep spectral index (α-1), similar to what is found in other clusters. The derived column density is NHI ~ 4 × 1020 cm-2 for a Tspin = 100 K. This detection supports the connection – already suggested for other restarted radio sources – between the presence of cold gas and restarting activity. The cold gas appears to be dominated by a blue-shifted component although the broad H I profile could also include gas with different kinematics. Understanding the duty cycle of the radio emission as well as the triggering mechanism for starting (or restarting) the radio-loud activity can provide important constraints to quantify the impact of AGN feedback on galaxy evolution. The study of these mechanisms at low frequencies using morphological and spectral information promises to bring new important insights in this field

Zur Versorgung der Arbeiter und Angestellten in Berlin bzw. dem Demokratischen Sektor Berlins und ausgewaehlten Betrieben in Berlin-Oberschoeneweide vom Ende des II. Weltkrieges bis Anfang der 50er Jahre unter besonderer Beruecksichtigung der Verhaeltnisse von Betrieb und Territorium

HUB(11) - 83 HB 2353, T. 1, 2 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Ueber den Zusammenhang zwischen sozialistischem Wettbewerb und den Formen und Methoden der materiellen und moralischen Stimulierung untersucht am Beispiel des VEB Chemieanlagenbau Stassfurt-Kombinat ; 1970 bis 1978

HUB(11) - 87 HB 1478 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Psychologische Aspekte bei Massnahmen zur Wehrerziehung Jugendlicher am Beispiel von Schuelerinnen und Schuelern einer Erweiterten Oberschule

SIGLEMBD - 76 34 0078 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Cardioprotection against reperfusion injury is maximal with only two minutes of sevoflurane administration in rats

PURPOSE: Volatile anesthetics can protect the heart against reperfusion injury. When sevoflurane is given for the first 15 min of reperfusion, a concentration corresponding to one minimum alveolar concentration (MAC) provides a maximum protective effect. The present study addresses the question of how long sevoflurane has to be administered to achieve the best cardioprotection. METHODS: Chloralose anesthetized rats were subjected to a 25-min occlusion of a major coronary artery, followed by 90 min of reperfusion. During the initial phase of reperfusion, an end-tidal concentration of 2.4 vol.% of sevoflurane (1 MAC) was given for two (n = 8), five (n = 8) or ten minutes (n = 7). Seven rats served as untreated controls. We measured left ventricular (LV) pressure, mean aortic pressure and infarct size (triphenyltetrazolium staining). RESULTS: Administration of sevoflurane for two minutes resulted in the greatest reduction of infarct size to 15% (8-22 [mean (95% confidence interval)] of the area at risk compared with controls [51 (47-55) %, P < 0.001]. Five or ten minutes of sevoflurane administration reduced infarct size to 26 (18-34) and 26 (18-35) % [P < 0.05], respectively. The cardiodepressant effect of sevoflurane varied with the duration of its administration: LV dP/dt was reduced from 6332 mmHg x sec(-1) (5771-6894) during baseline to 4211 mmHg x sec(-1) (3031-5391), 3811 mmHg x sec(-1) (2081-5540) and 3612 mmHg x sec(-1) (2864-4359) after two, five and ten minutes of reperfusion, respectively. CONCLUSION: Administration of 1 MAC sevoflurane for the first two minutes of reperfusion effectively protects the heart against reperfusion injury in rats in vivo. A longer administration time had lesser cardioprotective effects in this experimental mode

Kulturpolitische Aspekte in der Europapolitik kapitalistischer Staaten, insbesondere der BRD, gegenueber sozialistischen Laendern

HUB(11) - 90 HB 1197 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman