X-ray/UV campaign on the Mrk 279 outflow: density diagnostics in Active Galactic Nuclei using O V K-shell absorption lines

One of the main problems in modeling the ionised outflows in Active Galactic Nuclei is the unknown distance of the outflowing wind to the central source. Only if the density is known this distance can be determined through the ionisation parameter. Here we study density diagnostics based upon O V transitions. O V is known to have metastable levels that are density dependent. We study the population of those levels under photoionisation equilibrium conditions and determine for which parameter range they can have a significant population. We find that resonance line trapping plays an important role in reducing the critical densities above which the metastable population becomes important. We investigate the K-shell absorption lines from these metastable levels. Provided that there is a sufficient population of the metastable levels, the corresponding K-shell absorption lines are detectable and are well separated from the main absorption line originating from the ground state. We then present the Chandra LETGS spectrum of the Seyfert 1 galaxy Mrk 279 that may show for the first time the presence of these metastable level absorption lines. A firm identification is not yet possible due to both uncertainties in the observed wavelength of the strongest line as well as uncertainties in the predicted wavelength. If the line is indeed due to absorption from O V, then we deduce a distance to the central source of one light week to a few light months, depending upon the importance of additional heating processes.Comment: 10 pages, 8 figures, submitted to Astronomy & Astrophysics, main journa

Metal enrichment processes

There are many processes that can transport gas from the galaxies to their environment and enrich the environment in this way with metals. These metal enrichment processes have a large influence on the evolution of both the galaxies and their environment. Various processes can contribute to the gas transfer: ram-pressure stripping, galactic winds, AGN outflows, galaxy-galaxy interactions and others. We review their observational evidence, corresponding simulations, their efficiencies, and their time scales as far as they are known to date. It seems that all processes can contribute to the enrichment. There is not a single process that always dominates the enrichment, because the efficiencies of the processes vary strongly with galaxy and environmental properties.Comment: 18 pages, 8 figures, accepted for publication in Space Science Reviews, special issue "Clusters of galaxies: beyond the thermal view", Editor J.S. Kaastra, Chapter 17; work done by an international team at the International Space Science Institute (ISSI), Bern, organised by J.S. Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke

Inflammatory biomarkers in Alzheimer's disease plasma

Introduction: Plasma biomarkers for Alzheimer's disease (AD) diagnosis/stratification are a \u201cHoly Grail\u201d of AD research and intensively sought; however, there are no well-established plasma markers. Methods: A hypothesis-led plasma biomarker search was conducted in the context of international multicenter studies. The discovery phase measured 53 inflammatory proteins in elderly control (CTL; 259), mild cognitive impairment (MCI; 199), and AD (262) subjects from AddNeuroMed. Results: Ten analytes showed significant intergroup differences. Logistic regression identified five (FB, FH, sCR1, MCP-1, eotaxin-1) that, age/APO\u3b54 adjusted, optimally differentiated AD and CTL (AUC: 0.79), and three (sCR1, MCP-1, eotaxin-1) that optimally differentiated AD and MCI (AUC: 0.74). These models replicated in an independent cohort (EMIF; AUC 0.81 and 0.67). Two analytes (FB, FH) plus age predicted MCI progression to AD (AUC: 0.71). Discussion: Plasma markers of inflammation and complement dysregulation support diagnosis and outcome prediction in AD and MCI. Further replication is needed before clinical translation

Mass outflow in the Seyfert 1 Galaxy NGC 5548

We present a study of the intrinsic UV absorption and emission lines in an historically low-state spectrum of the Seyfert 1 galaxy NGC 5548, which we obtained in 2004 February at high spatial and spectral resolution with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. We isolate a component of emission with a width of 680 km s–1 that arises from an "intermediate-line region" (ILR), similar to that we discovered in NGC 4151, at a distance of ~1 pc from the central continuum source. From a detailed analysis of the five intrinsic absorption components in NGC 5548 and their behavior over a span of eight years, we present evidence that most of the UV absorbers only partially cover the ILR and do not cover an extended region of UV continuum emission, most likely from hot stars in the circumnuclear region. We also find that four of the UV absorbers are at much greater distances (greater than 70 pc) than the ILR, and none have sufficient N V or C IV column densities to be the ILR in absorption. At least a portion of the UV absorption component 3, at a radial velocity of –530 km s–1, is likely responsible for most of the X-ray absorption, at a distance less than 7 pc from the central source. The fact that we see the ILR in absorption in NGC 4151 and not in NGC 5548 suggests that the ILR is located at a relatively large polar angle (~45°) with respect to the narrow-line region outflow axis

Expression and activity of key hepatic gluconeogenesis enzymes in response to increasing intravenous infusions of glucose in dairy cows

The present study aimed at investigating whether increasing concentrations of glucose supply have a depressive effect on the mRNA abundance and activity of key gluconeogenic enzymes in dairy cows. Twelve Holstein-Friesian dairy cows in mid-lactation were intravenously infused with saline (SI; n = 6) or a 40% glucose solution (GI; n = 6). For GI cows, the infusion dose increased by 1.25%/d relative to the initial NEl requirement until a maximum dose equating to surplus 30% NEl was reached on d 24. Cows receiving SI received an equivalent volume of 0.9% saline solution. Blood samples were taken every 2 d, and liver biopsies were collected every 8 d. A treatment x quadratic dose interaction (P < 0.01) was observed for the concentration of plasma glucose and serum insulin. The interactions were due to positive quadratic responses of the concentrations of glucose and insulin for GI cows, whereas the concentrations of glucose and insulin did not change over time for SI cows. The concentration of β-hydroxybutyric acid (BHBA) and serum urea nitrogen (BUN) responded in a treatment x quadratic dose manner, such that greater decreases (P < 0.01) in BHBA and BUN concentrations were observed for cows receiving GI than SI as the dosage increased. Serum NEFA concentration tended to follow a similar pattern as serum BHBA and BUN; however, the interaction was not significant (P = 0.07). The mRNA abundance of gluconeogenesis enzymes followed a linear treatment x dose interaction (P < 0.05) for only pyruvate carboxylase (PC), which was paralleled by a trend for a linear treatment x dose interaction (P = 0.13) for PC enzyme activity. The least PC expression and activity were observed at the largest glucose dosage. The activity, but not mRNA abundance, of fructose 1,6-bisphosphatase (FBPase) showed treatment x quadratic dose interactions (P < 0.05) with decreasing activity at increasing glucose dose. Activities and expression of phosphoenolpyruvate carboxykinase and glucose 6-phosphatase were not affected (P > 0.25) by treatment. In conclusion, hepatic gluconeogenic enzymes are only moderately affected by slowly increasing glucose supply, including a translational or posttranslational downregulation of FBPase activity and a decrease in the mRNA abundance of PC with possible consequences for PC enzyme activity

1st international round robin test on safety characteristics of hybrid mixtures

There is no applicable existing standard for the determination of safety characteristics for hybrid mixtures. While developing a new standard in a joint research project in Germany first results from parameter studies led to a standard procedure that can be adopted by laboratories that are already testing dusts in the so called 20L-sphere with as little additional effort as necessary. In fact, one of the main objectives of this research project was to keep modifications and adjustments from the generally accepted dust testing procedures as easy and minimal as possible so as to limit potential deviations from one laboratory to another. In this first round robin test on hybrid mixtures ever, with methane as gas component and a specific corn starch as dust sample, the practicality of the whole procedure, the scattering of the results and the deviation between the testing apparatuses is investigated. This paper summarizes the experimental procedure adopted and objectives of the first round-robin phase involving three of the four original German companies, plus volunteering laboratories from Australia, Belgium, Czech Republic, France, Poland and P.R. China. The results will have an impact on the new standard and may lead to robust data for later simulation purposes.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Fluid Mechanic