271 research outputs found
Marktstemming mei: prijzen en belangrijke ontwikkelingen
De maand maart werd gekenmerkt door veel regenval, waardoor de zaaiwerkzaamheden een flinke achterstand opliepen. Aan de kostenkant springen vooral de sterk stijgende prijzen van energie en kunstmest in het oog. Voor veel akkerbouwproducten zijn de prijzen opgelopen. Door quotumverruiming en stijgende melkproductie zet de daling van de melkprijs door
The German Astrophysical Virtual Observatory — Knowledge networking for astronomy in Germany and abroad
We describe the work of the German Astrophysical Virtual Observatory (GAVO). GAVO is the German node in the world-wide international virtual observatory (VObs) effort aimed at making geographically distributed astrophysical data and applications more readily available to the community and to find ways of combining these in an interoperable network so as to create new ways of doing science. In this presentation we give a short overview of the ideas behind the virtual observatory and describe the efforts of the International Virtual Observatory Alliance (IVOA). We describe then in detail the activities of GAVO, both in its first pilot phase and in the recently initiated second phase. Here we will pay particular attention to the effort spearheaded by GAVO to include results of large scale computer simulations in the VObs efforts, both national and international
Using Virtual Observatory techniques to search for Adaptive Optics suitable AGN
Until recently, it has been possible only for nearby galaxies to study the
scaling relations between central black hole and host galaxy in detail. Because
of the small number densities at low redshift, (luminous) AGN are
underrepresented in such detailed studies. The advent of adaptive optics (AO)
at large telescopes helps overcoming this hurdle, allowing to reach small
linear scales over a wide range in redshift. Finding AO-suitable targets, i.e.,
AGN having a nearby reference star, and carrying out an initial multiwavelength
classification is an excellent use case for the Virtual Observatory. We present
our Virtual-Observatory approach to select an AO-suitable catalog of
X-ray-emitting AGN at redshifts 0.1<z<1.Comment: 4 pages, 5 figures, submitted to "EURO-VO AIDA workshop:
Multiwavelength astronomy and Virtual Observatory", ESAC, Spain, 1-3 Dec.
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The German Astrophysical Virtual Observatory — Knowledge networking for astronomy in Germany and abroad
We describe the work of the German Astrophysical Virtual Observatory (GAVO). GAVO is the German node in the world-wide international virtual observatory (VObs) effort aimed at making geographically distributed astrophysical data and applications more readily available to the community and to find ways of combining these in an interoperable network so as to create new ways of doing science. In this presentation we give a short overview of the ideas behind the virtual observatory and describe the efforts of the International Virtual Observatory Alliance (IVOA). We describe then in detail the activities of GAVO, both in its first pilot phase and in the recently initiated second phase. Here we will pay particular attention to the effort spearheaded by GAVO to include results of large scale computer simulations in the VObs efforts, both national and international
Risk stratification to improve Pediatric Early Warning Systems: it is all about the context
Contains fulltext :
208059.pdf (publisher's version ) (Open Access
Galaxy formation in the Planck cosmology - II. Star-formation histories and post-processing magnitude reconstruction
We adapt the L-Galaxies semi-analytic model to follow the star-formation
histories (SFH) of galaxies -- by which we mean a record of the formation time
and metallicities of the stars that are present in each galaxy at a given time.
We use these to construct stellar spectra in post-processing, which offers
large efficiency savings and allows user-defined spectral bands and dust models
to be applied to data stored in the Millennium data repository.
We contrast model SFHs from the Millennium Simulation with observed ones from
the VESPA algorithm as applied to the SDSS-7 catalogue. The overall agreement
is good, with both simulated and SDSS galaxies showing a steeper SFH with
increased stellar mass. The SFHs of blue and red galaxies, however, show poor
agreement between data and simulations, which may indicate that the termination
of star formation is too abrupt in the models.
The mean star-formation rate (SFR) of model galaxies is well-defined and is
accurately modelled by a double power law at all redshifts: SFR proportional to
, where Gyr, is the age of the
stars and is the loopback time to the onset of galaxy formation; above a
redshift of unity, this is well approximated by a gamma function: SFR
proportional to , where Gyr. Individual
galaxies, however, show a wide dispersion about this mean. When split by mass,
the SFR peaks earlier for high-mass galaxies than for lower-mass ones, and we
interpret this downsizing as a mass-dependence in the evolution of the quenched
fraction: the SFHs of star-forming galaxies show only a weak mass dependence.Comment: Accepted version of the paper, to appear in MNRAS. Compared to the
original version, contains more detail on the post-processing of magnitudes,
including a table of rms magnitude errors. SFHs available on Millennium
database http://gavo.mpa-garching.mpg.de/MyMillennium
The Coarse Geometry of Merger Trees in \Lambda CDM
We introduce the contour process to describe the geometrical properties of
merger trees. The contour process produces a one-dimensional object, the
contour walk, which is a translation of the merger tree. We portray the contour
walk through its length and action. The length is proportional to to the number
of progenitors in the tree, and the action can be interpreted as a proxy of the
mean length of a branch in a merger tree.
We obtain the contour walk for merger trees extracted from the public
database of the Millennium Run and also for merger trees constructed with a
public Monte-Carlo code which implements a Markovian algorithm. The trees
correspond to halos of final masses between 10^{11} h^{-1} M_sol and 10^{14}
h^{-1} M_sol. We study how the length and action of the walks evolve with the
mass of the final halo. In all the cases, except for the action measured from
Markovian trees, we find a transitional scale around 3 \times 10^{12} h^{-1}
M_sol. As a general trend the length and action measured from the Markovian
trees show a large scatter in comparison with the case of the Millennium Run
trees.Comment: 7 pages, 5 figures, submitted to MNRA
The occurrence of adverse events in low-risk non-survivors in pediatric intensive care patients: an exploratory study
We studied the occurrence of adverse events (AEs) in low-risk non-survivors (LNs), compared to low-risk survivors (LSs), high-risk non-survivors (HNs), and high-risk survivors (HSs) in two pediatric intensive care units (PICUs). The study was performed as a retrospective patient record review study, using a PICU-trigger tool. A random sample of 48 PICU patients (0–18 years) was chosen, stratified into four subgroups of 12 patients: LNs, LSs, HNs, and HSs. Primary outcome was the occurrence of AEs. The severity, preventability, and nature of the indentified AEs were determined. In total, 45 AEs were found in 20 patients. The occurrence of AEs in the LN group was significantly higher compared to that in the LS group and HN group (AE occurrence: LN 10/12 patients, LS 1/12 patients; HN 2/12 patients; HS 7/12 patients; LN-LS difference, p < 0.001; LN-HN difference, p < 0.01). The AE rate in the LN group was significantly higher compared to that in the LS and HN groups (median [IQR]: LN 0.12 [0.07–0.29], LS 0 [0–0], HN 0 [0–0], and HS 0.03 [0.0–0.17] AE/PICU day; LN-LS difference, p < 0.001; LN-HN difference, p < 0.01). The distribution of the AEs among the four groups was as follows: 25 AEs (LN), 2 AEs (LS), 8 AEs (HN), and 10 AEs (HS). Fifteen of forty-five AEs were preventable. In 2/12 LN patients, death occurred after a preventable AE. Conclusion: The occurrence of AEs in LNs was higher compared to that in LSs and HNs. Some AEs were severe and preventable and contributed to mortality.(Table presented.
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