GX 339-4: back to life

We report preliminary results of a RossiXTE campaign on the 2002 outburst of the black-hole candidate GX 339-4. We show power density spectra of five observations during the early phase of the outburst. The first four power spectra show a smooth transition between a Low State and a Very High State. The fifth power spectrum resembles a High State, but a strong 6 Hz QPO appears suddenly within 16 seconds.Comment: 3 pages, 3 figures; to appear in Proceedings of the 4th Microquasar Workshop, eds. Ph Durouchoux, Y. Fuchs and J. Rodriguez, published by the Center for Space Physics: Kolkat

The MURALES survey. I. A dual AGN in the radio galaxy 3C459?

We observed the FRII radio galaxy 3C459 (z=0.22) with the MUSE spectrograph at the Very Large Telescope (VLT) as part of the MURALES project (a MUse RAdio Loud Emission line Snapshot survey). We detected diffuse nuclear emission and a filamentary ionized gas structure forming a one-sided, triangular-shaped region extending out to $\sim$80 kpc. The central emission line region is dominated by two compact knots of similar flux: the first (N1) cospatial with the radio core and the (N2) second located 1.2" (5.3 kpc) to the SE. The two regions differ dramatically from the point of view of velocity (with an offset of ~400 km/s), line widths, and line ratios. This suggests that we are observing a dual AGN system formed by a radio loud AGN and type 2 QSO companion, which is the result of the recent merger that also produced its disturbed host morphology. The alternative possibility that N2 is just a bright emission line knot resulting from, for example, a jet-cloud interaction, is disfavored because of 1) the presence of a high ionization bicone whose apex is located at N2; 2) the observed narrow line widths; 3) its line luminosity (~10^42 erg s-1) typical of luminous QSOs; and 4) its location, which is offset from the jet path. The putative secondary AGN must be highly obscured, since we do not detect any emission in the Chandra and infrared Hubble Space Telescope images.Comment: 6 pages, 6 figures, A&A in pres

Prolonged oral cannabinoid administration prevents neuroinflammation, lowers β-amyloid levels and improves cognitive performance in Tg APP 2576 mice

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Alzheimer's disease (AD) brain shows an ongoing inflammatory condition and non-steroidal anti-inflammatories diminish the risk of suffering the neurologic disease. Cannabinoids are neuroprotective and anti-inflammatory agents with therapeutic potential. [Methods]: We have studied the effects of prolonged oral administration of transgenic amyloid precursor protein (APP) mice with two pharmacologically different cannabinoids (WIN 55,212-2 and JWH-133, 0.2 mg/kg/day in the drinking water during 4 months) on inflammatory and cognitive parameters, and on 18F-fluoro-deoxyglucose (18FDG) uptake by positron emission tomography (PET). [Results]: Novel object recognition was significantly reduced in 11 month old Tg APP mice and 4 month administration of JWH was able to normalize this cognitive deficit, although WIN was ineffective. Wild type mice cognitive performance was unaltered by cannabinoid administration. Tg APP mice showed decreased 18FDG uptake in hippocampus and cortical regions, which was counteracted by oral JWH treatment. Hippocampal GFAP immunoreactivity and cortical protein expression was unaffected by genotype or treatment. In contrast, the density of Iba1 positive microglia was increased in Tg APP mice, and normalized following JWH chronic treatment. Both cannabinoids were effective at reducing the enhancement of COX-2 protein levels and TNF-α mRNA expression found in the AD model. Increased cortical β-amyloid (Aβ) levels were significantly reduced in the mouse model by both cannabinoids. Noteworthy both cannabinoids enhanced Aβ transport across choroid plexus cells in vitro. [Conclusions]: In summary we have shown that chronically administered cannabinoid showed marked beneficial effects concomitant with inflammation reduction and increased Aβ clearance.This work was supported by the Spanish Ministry of Science and Technology (SAF 2005-02845 to M.L.C). A.M.M-M. was recipient a fellowship from the Ministry of Education and Science.Peer Reviewe

Unifying models for X-ray selected and Radio selected BL Lac Objects

We discuss alternative interpretations of the differences in the Spectral Energy Distributions (SEDs) of BL Lacs found in complete Radio or X-ray surveys. A large body of observations in different bands suggests that the SEDs of BL Lac objects appearing in X-ray surveys differ from those appearing in radio surveys mainly in having a (synchrotron) spectral cut-off (or break) at much higher frequency. In order to explain the different properties of radio and X-ray selected BL Lacs Giommi and Padovani proposed a model based on a common radio luminosity function. At each radio luminosity, objects with high frequency spectral cut-offs are assumed to be a minority. Nevertheless they dominate the X-ray selected population due to the larger X-ray-to-radio-flux ratio. An alternative model explored here (reminiscent of the orientation models previously proposed) is that the X-ray luminosity function is "primary" and that at each X-ray luminosity a minority of objects has larger radio-to-X-ray flux ratio. The predictions of the two scenarios, computed via a Montecarlo technique, are compared with the observed properties of BL Lacs in the two samples extracted respectively from the 1 Jy radio survey and the Einstein Slew Survey. We show that both models can explain a number but not all the observed features. We then propose a completely new approach, based on the idea that the physical parameter which governs the shape of the SEDs, is (or is associated with) the bolometric luminosity. Assuming an empirical relation between spectral shape and luminosity we show that the observational properties of the two surveys can be reproduced at least with the same accuracy as the two previous models.Comment: 21 pages, when TeX-ed including tables (3) and figures (8). MNRAS latex. mn.sty and psfig.sty included. Accepted for pubblication in MNRAS. Also available at http://www.sissa.it/~fossati/pub_list.htm

Determination of Deoxynivalenol in the Urine of Pregnant Women in the UK

Deoxynivalenol (DON) is one of the most commonly occurring trichothecenes, produced mainly by Fusarium graminearum. Little is known about the effect of DON exposure or the levels of DON exposure that occur during pregnancy. The project aimed to provide data on levels of total DON and de-epoxi Deoxynivalenol (DOM-1) in pregnant human urine samples analysed by liquid chromatography-mass spectrometry (LC-MS). Morning urine samples were collected over two consecutive days from 42 volunteers and associated food consumption was recorded for the 24 h prior to the sample. Spearman’s rho non-parametric test for correlation was used to assess the data. Levels of DON did not differ significantly between day 1 (mean 29.7 ng/mL urine or 40.1 ng DON/mg creatinine) and day 2 (mean 28.7 ng/mL urine or 38.8 ng DON/mg creatinine ng/mL/day) urine samples. The only significant positive correlation was found between total ng DON/mg creatinine and parity (rho = 0.307, n = 42, p < 0.005 two-tailed) and total ng DON/mg creatinine with baked goods on day 1 (rho = 0.532, n = 42, p < 0.0005 two-tailed). This study provides data on the DON levels in pregnancy in this suburban population and reassurance that those levels are within acceptable limits

Prolonged oral cannabinoid administration prevents neuroinflammation, lowers β-amyloid levels and improves cognitive performance in Tg APP 2576 mice

Background: Alzheimer’s disease (AD) brain shows an ongoing inflammatory condition and non-steroidal antiinflammatories diminish the risk of suffering the neurologic disease. Cannabinoids are neuroprotective and antiinflammatory agents with therapeutic potential. Methods: We have studied the effects of prolonged oral administration of transgenic amyloid precursor protein (APP) mice with two pharmacologically different cannabinoids (WIN 55,212-2 and JWH-133, 0.2 mg/kg/day in the drinking water during 4 months) on inflammatory and cognitive parameters, and on 18F-fluoro-deoxyglucose (18FDG) uptake by positron emission tomography (PET). Results: Novel object recognition was significantly reduced in 11 month old Tg APP mice and 4 month administration of JWH was able to normalize this cognitive deficit, although WIN was ineffective. Wild type mice cognitive performance was unaltered by cannabinoid administration. Tg APP mice showed decreased 18FDG uptake in hippocampus and cortical regions, which was counteracted by oral JWH treatment. Hippocampal GFAP immunoreactivity and cortical protein expression was unaffected by genotype or treatment. In contrast, the density of Iba1 positive microglia was increased in Tg APP mice, and normalized following JWH chronic treatment. Both cannabinoids were effective at reducing the enhancement of COX-2 protein levels and TNF-a mRNA expression found in the AD model. Increased cortical b-amyloid (Ab) levels were significantly reduced in the mouse model by both cannabinoids. Noteworthy both cannabinoids enhanced Ab transport across choroid plexus cells in vitro. Conclusions: In summary we have shown that chronically administered cannabinoid showed marked beneficial effects concomitant with inflammation reduction and increased Ab clearanceThis work was supported by the Spanish Ministry of Science and Technology (SAF 2005-02845 to M.L.C). A.M.M-M. was recipient a fellowship from the Ministry of Education and Scienc