Significant differences in markers of oxidant injury between idiopathic and bronchopulmonary-dysplasia-associated pulmonary hypertension in children

While oxidant stress is elevated in adult forms of pulmonary hypertension (PH), levels of oxidant stress in pediatric PH are unknown. The objective of this study is to measure F2-isoprostanes, a marker of oxidant stress, in children with idiopathic pulmonary hypertension (IPH) and PH due to bronchopulmonary dysplasia (BPD). We hypothesized that F2-isoprostanes in pediatric IPH and PH associated with BPD will be higher than in controls. Plasma F2-isoprostanes were measured in pediatric PH patients during clinically indicated cardiac catheterization and compared with controls. F2-Isoprostane levels were compared between IPH, PH due to BD, and controls. Five patients with IPH, 12 with PH due to BPD, and 20 control subjects were studied. Patients with IPH had statistically higher isoprostanes than controls 62 pg/mL (37–210) versus 20 pg/mL (16–27), ). The patients with PH and BPD had significantly lower isoprostanes than controls 15 pg/mL (8–17) versus 20 pg/ml (16–27), . F2-isoprostanes are elevated in children with IPH compared to both controls and patients with PH secondary to BPD. Furthermore, F2-isoprostanes in PH secondary to BPD are lower than control levels. These findings suggest that IPH and PH secondary to BPD have distinct mechanisms of disease pathogenesis

A novel high dynamic six phase 120 kW Power Hardware in the Loop Emulation Test Bench for emulating AC/DC Grids and Electrical Machines

This paper presents a highly customizable 120kVA Power-Hardware-in-the-Loop test bench. The output stage consist of two identical Parallel Hybrid Converters each with a 17-level output voltage and an effective switching frequency of 1MHz. The Parallel Hybrid Converters can provide 3-phase AC or bipolar DC as output voltage. Thus, one 6-AC, 3-AC or DC system or two systems with 2x3-AC, 1x3-AC and 1xDC or 2xDC can be emulated

A novel high dynamic six phase 120 kW Power Hardware in the Loop Emulation Test Bench for emulating AC/DC Grids and Electrical Machines

This paper presents a highly customizable 120kVA Power-Hardware-in-the-Loop test bench. The output stage consist of two identical Parallel Hybrid Converters each with a 17-level output voltage and an effective switching frequency of 1MHz. The Parallel Hybrid Converters can provide 3-phase AC or bipolar DC as output voltage. Thus, one 6-AC, 3-AC or DC system or two systems with 2x3-AC, 1x3-AC and 1xDC or 2xDC can be emulated

Galaxy And Mass Assembly (GAMA): the dependence of star formation on surface brightness in low-redshift galaxies

The star-formation rate in galaxies is well known to correlate with stellar mass (the ‘star-forming main sequence’). Here, we extend this further to explore any additional dependence on galaxy surface brightness, a proxy for stellar mass surface density. We use a large sample of low-redshift (z ≤ 0.08) galaxies from the Galaxy And Mass Assembly survey which have both spectral energy distribution (SED) derived star-formation rates and photometric bulge-disc decompositions, the latter providing measures of disc surface brightness and disc masses. Using two samples, one of galaxies fitted by a single component with Sérsic index below 2 and one of the discs from two-component fits, we find that once the overall mass dependence of star-formation rate is accounted for, there is no evidence in either sample for a further dependence on stellar surface density

Galaxy and Mass Assembly (GAMA): Demonstrating the Power of WISE in the Study of Galaxy Groups to z \u3c 0.1

Combining high-fidelity group characterization from the Galaxy and Mass Assembly survey and source-tailored z \u3c 0.1 photometry from the Wide-Field Infrared Survey Explorer (WISE) survey, we present a comprehensive study of the properties of ungrouped galaxies, compared to 497 galaxy groups (4 ≤ N FoF ≤ 20) as a function of stellar and halo mass. Ungrouped galaxies are largely unimodal in WISE color, the result of being dominated by star-forming, late-type galaxies. Grouped galaxies, however, show a clear bimodality in WISE color, which correlates strongly with stellar mass and morphology. We find evidence for an increasing early-type fraction, in stellar mass bins between 1010 M o˙ ≲ M stellar ≲ 1011 M o˙, with increasing halo mass. Using ungrouped, late-type galaxies with star-forming colors (W2-W3 \u3e 3), we define a star-forming main sequence (SFMS), which we use to delineate systems that have moved below the sequence ( quenched for the purposes of this work). We find that with increasing halo mass, the relative number of late-type systems on the SFMS decreases, with a corresponding increase in early-type, quenched systems at high stellar mass (M stellar \u3e 1010.5 M o˙), consistent with mass quenching. Group galaxies with masses M stellar \u3c 1010.5 M o˙ show evidence of quenching consistent with environmentally driven processes. The stellar mass distribution of late-type, quenched galaxies suggests that it may be an intermediate population as systems transition from being star-forming and late-type to the red sequence. Finally, we use the projected area of groups on the sky to extract groups that are (relatively) compact for their halo mass. Although these show a marginal increase in their proportion of high-mass and early-type galaxies compared to nominal groups, a clear increase in quenched fraction is not evident

Elliptic and hyperelliptic magnetohydrodynamic equilibria

The present study is a continuation of a previous one on "hyperelliptic" axisymmetric equilibria started in [Tasso and Throumoulopoulos, Phys. Plasmas 5, 2378 (1998)]. Specifically, some equilibria with incompressible flow nonaligned with the magnetic field and restricted by appropriate side conditions like "isothermal" magnetic surfaces, "isodynamicity" or P + B^2/2 constant on magnetic surfaces are found to be reducible to elliptic integrals. The third class recovers recent equilibria found in [Schief, Phys. Plasmas 10, 2677 (2003)]. In contrast to field aligned flows, all solutions found here have nonzero toroidal magnetic field on and elliptic surfaces near the magnetic axis.Comment: 9 page

Galaxy and Mass Assembly (GAMA): Morphological transformation of galaxies across the green valley

We explore constraints on the joint photometric and morphological evolution of typical low redshift galaxies as they move from the blue cloud through the green valley and onto the red sequence. We select GAMA survey galaxies with $10.25<{\rm log}(M_*/M_\odot)<10.75$ and $z<0.2$ classified according to their intrinsic $u^*-r^*$ colour. From single component S\'ersic fits, we find that the stellar mass-sensitive $K-$band profiles of red and green galaxy populations are very similar, while $g-$band profiles indicate more disk-like morphologies for the green galaxies: apparent (optical) morphological differences arise primarily from radial mass-to-light ratio variations. Two-component fits show that most green galaxies have significant bulge and disk components and that the blue to red evolution is driven by colour change in the disk. Together, these strongly suggest that galaxies evolve from blue to red through secular disk fading and that a strong bulge is present prior to any decline in star formation. The relative abundance of the green population implies a typical timescale for traversing the green valley $\sim 1-2$~Gyr and is independent of environment, unlike that of the red and blue populations. While environment likely plays a r\^ole in triggering the passage across the green valley, it appears to have little effect on time taken. These results are consistent with a green valley population dominated by (early type) disk galaxies that are insufficiently supplied with gas to maintain previous levels of disk star formation, eventually attaining passive colours. No single event is needed quench their star formation

Are galaxies with AGN a transition population?

We present the results of an analysis of a well-selected sample of galaxies with active and inactive galactic nuclei from the Sloan Digital Sky Survey, in the range 0.01 < z < 0.16. The SDSS galaxy catalogue was split into two classes of active galaxies, Type~2 AGN and composites, and one set of inactive, star-forming/passive galaxies. For each active galaxy, two inactive control galaxies were selected by matching redshift, absolute magnitude, inclination, and radius. The sample of inactive galaxies naturally divides into a red and a blue sequence, while the vast majority of AGN hosts occur along the red sequence. In terms of H-alpha equivalent width, the population of composite galaxies peaks in the valley between the two modes, suggesting a transition population. However, this effect is not observed in other properties such as colour-magnitude space, or colour-concentration plane. Active galaxies are seen to be generally bulge-dominated systems, but with enhanced H-alpha emission compared to inactive red-sequence galaxies. AGN and composites also occur in less dense environments than inactive red-sequence galaxies, implying that the fuelling of AGN is more restricted in high-density environments. These results are therefore inconsistent with theories in which AGN host galaxies are a `transition' population. We also introduce a systematic 3D spectroscopic imaging survey, to quantify and compare the gaseous and stellar kinematics of a well-selected, distance-limited sample of up to 20 nearby Seyfert galaxies, and 20 inactive control galaxies with well-matched optical properties. The survey aims to search for dynamical triggers of nuclear activity and address outstanding controversies in optical/IR imaging surveys.Comment: 12 pages, 8 figures, accepted by MNRA

GALICS -- VI. Modelling Hierarchical Galaxy Formation in Clusters

High-resolution N-body re-simulations of 15 massive (10^{14}-10^{15} Msun) dark matter haloes have been combined with the hybrid galaxy formation model GalICS (Hatton et al. 2003), to study the formation and evolution of galaxies in clusters, within the framework of the hierarchical merging scenario. New features in GalICS include a better description of galaxy positioning within dark matter haloes, a more reliable computation of the temperature of the inter-galactic medium as a function of redshift, and a description of the ram pressure stripping process. We focus on the luminosity functions, morphological fractions and colour distributions of galaxies in clusters and in cluster outskirts, at z=0. No systematic dependency on cluster richness is found either for the galaxy luminosity functions, morphological mixes, or colour distributions. Moving from higher density (cluster cores), to lower density environments (cluster outskirts), we detect a progressive flattening of the luminosity functions, an increase of the fraction of spirals and a decrease of that of ellipticals and S0s, and the progressive emergence of a bluer tail in the distributions of galaxy colours, especially for spirals. As compared to cluster spirals, early-type galaxies show a flatter luminosity function, and more homogeneous and redder colours. An overall good agreement is found between our results and the observations, particularly in terms of the cluster luminosity functions and morphological mixes. However, some discrepancies are also apparent, with too faint magnitudes of the brightest cluster members, especially in the B band, and galaxy colours tendentially too red (or not blue enough) in the model, with respect to the observations. Finally, ram pressure stripping appears to affect very little our results.Comment: Accepted for publication in MNRAS. 17 pages, 11 figures. High-resolution Figure 1 available in the on-line version of the pape