The M_BH-M_star relation of obscured AGNs at high redshift

We report the detection of broad Halpha emission in three X-ray selected obscured AGNs at z=1-2. By exploiting the Halpha width and the intrinsic X-ray luminosity, we estimate their black hole masses, which are in the range 0.1-3x10^9 Msun. By means of multi-band photometric data, we measure the stellar mass of their host galaxy and, therefore, infer their M_BH/M_star ratio. These are the first obscured AGNs at high-z, selected based on their black hole accretion (i.e. on the basis of their X-ray luminosity), that can be located on the M_BH-M_star relation at high-z. All of these obscured high-z AGNs are fully consistent with the local M_BH-M_star relation. This result conflicts with those for other samples of AGNs in the same redshift range, whose M_BH/M_star ratio departs significantly from the value observed in local galaxies. We suggest that the obscured AGNs in our sample are in an advanced evolutionary stage, have already settled onto the local M_BH-M_star relation, and whose nuclear activity has been temporarily revived by recent galaxy interactions.Comment: 4 pages, 2 figures, accepted for publication in A&A Letters, slightly revised discussion on SMG

Identification of a non-host semiochemical from miniature pinscher, Canis lupus familiaris, that repels Rhipicephalus sanguineus sensu lato (Acari: Ixodidae)

It is already known that the beagle breed of domestic dogs produces semiochemicals capable of repelling the brown dog tick, Rhipicephalus sanguineus sensu lato (s.l.). With a view to discovering new non-host semiochemicals as tick repellents, we compared the semiochemicals produced by a putative tick-resistant breed of dog, miniature pinscher, with known tick-resistant (beagle) and tick-susceptible (English cocker spaniel) breeds. Two non-host compounds produced by beagles, i.e. 2-hexanone and benzaldehyde, were shown to be present in volatile samples collected from all three breeds. Furthermore, two compounds, 6-methyl-5-hepten-2-one and 1,2,4-trimethylbenzene, were found in higher amounts in volatile samples collected from miniature pinscher dogs. The mean amounts of benzaldehyde, 2- hexanone and 1,2,4-trimethylbenzene were similar for beagles and miniature pinschers and higher than the means observed for cocker spaniels, whereas the mean amount of 6-methyl-5-hepten-2-one produced by miniature pinschers was significantly higher than for the other breeds of dogs. In Petri-dish assays with adult R. sanguineus, 6-methyl-5- hepten-2-one was repellent for all observation periods evaluated for the two highest concentrations (0.100 and 0.200 mg.cm-2). Our results support our hypothesis that miniature pinschers are a tick-resistant dog breed and agree with previous observations of miniature pinschers being the breed least parasitized by ticks. Furthermore, the non-host semiochemical 6-methyl-5-hepten-2-one has potential to be developed for use as a repellent for the protection of susceptible dogs from R. sanguineus s.l. ticks

On the High‐Energy Spectral Component and Fine Time Structure of Terrestrial Gamma Ray Flashes

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Alginate inhibits iron absorption from ferrous gluconate in a randomized controlled trial and reduces iron uptake into Caco-2 cells

Previous in vitro results indicated that alginate beads might be a useful vehicle for food iron fortification. A human study was undertaken to test the hypothesis that alginate enhances iron absorption. A randomised, single blinded, cross-over trial was carried out in which iron absorption was measured from serum iron appearance after a test meal. Overnight-fasted volunteers (n=15) were given a test meal of 200g cola-flavoured jelly plus 21 mg iron as ferrous gluconate, either in alginate beads mixed into the jelly or in a capsule. Iron absorption was lower from the alginate beads than from ferrous gluconate (8.5% and 12.6% respectively, p=0.003). Sub-group B (n=9) consumed the test meals together with 600 mg calcium to determine whether alginate modified the inhibitory effect of calcium. Calcium reduced iron absorption from ferrous gluconate by 51%, from 11.5% to 5.6% (p=0.014), and from alginate beads by 37%, from 8.3% to 5.2% (p=0.009). In vitro studies using Caco-2 cells were designed to explore the reasons for the difference between the previous in vitro findings and the human study; confirmed the inhibitory effect of alginate. Beads similar to those used in the human study were subjected to simulated gastrointestinal digestion, with and without cola jelly, and the digestate applied to Caco-2 cells. Both alginate and cola jelly significantly reduced iron uptake into the cells, by 34% (p=0.009) and 35% (p=0.003) respectively. The combination of cola jelly and calcium produced a very low ferritin response, 16.5% (p<0.001) of that observed with ferrous gluconate alone. The results of these studies demonstrate that alginate beads are not a useful delivery system for soluble salts of iron for the purpose of food fortification

Slabs of stabilized jellium: Quantum-size and self-compression effects

We examine thin films of two simple metals (aluminum and lithium) in the stabilized jellium model, a modification of the regular jellium model in which a constant potential is added inside the metal to stabilize the system for a given background density. We investigate quantum-size effects on the surface energy and the work function. For a given film thickness we also evaluate the density yielding energy stability, which is found to be slightly higher than the equilibrium density of the bulk system and to approach this value in the limit of thick slabs. A comparison of our self-consistent calculations with the predictions of the liquid-drop model shows the validity of this model.Comment: 7 pages, 6 figures, to appear in Phys. Rev.

Hierarchically Porous Gd3+-Doped CeO2 Nanostructures for the Remarkable Enhancement of Optical and Magnetic Properties

Rare earth ion-doped CeO2 has attracted more and more attention because of its special electrical, optical, magnetic, or catalytic properties. In this paper, a facile electrochemical deposition route was reported for the direct growth of the porous Gd-doped CeO2. The formation process of Gd-doped CeO2 composites was investigated. The obtained deposits were characterized by SEM, EDS, XRD, and XPS. The porous Gd3+- doped CeO2 (10 at% Gd) displays a typical type I adsorption isotherm and yields a large specific surface area of 135 m2/g. As Gd3+ ions were doped into CeO2 lattice, the absorption spectrum of Gd3+-doped CeO2 nanocrystals exhibited a red shift compared with porous CeO2 nanocrystals and bulk CeO2, and the luminescence of Gd3+-doped CeO2 deposits was remarkably enhanced due to the presence of more oxygen vacancies. In addition, the strong magnetic properties of Gd-doped CeO2 (10 at% Gd) were observed, which may be caused by Gd3+ ions or more oxygen defects in deposits. In addition, the catalytic activity of porous Gd-doped CeO2 toward CO oxidation was studied