73 research outputs found
Recent benthic foraminiferal assemblages from the Celtic Sea (South Western Approaches, NE Atlantic)
The faunal composition and diversity pattern of Recent benthic foraminifera from the shelf and slope of the South Western Approaches (Celtic Sea) were assessed. The sampling stations cover a depth range from 100 to 500 m. A total number of 294 species was recorded, of which 89 were found exclusively in the living fauna and 118 only in the dead assemblage, whereas 87 species were found in both assemblages. The faunal composition revealed a distinct bisection of the living fauna on the shelf. While certain distribution patterns of living dominant species were recognized along a NE-SW trending transect towards the shelf edge, the living fauna changed within small depth intervals and geographic position on the slope. Causes for this structured slope assemblages were probably along-slope currents of varying strengths, as well as variations in topography and bottom sediments. Analyses of population densities and diversity patterns determined high densities along the shelf edge and at one slope station, as well as an increasing diversity with water depth. A comparison with literature
data from the same area yields distinct differences in faunal composition on the shelf and slope. The diversity was similar on the shelf, but higher at corresponding stations on the slope. We conclude that the faunal composition was highly influenced by the time and methods of sampling. In order to obtain consistent results in regional studies, all samples should be taken in a short time interval and by using the same sampling device. In addition, we depicted the influences of environmental parameters on dead faunal assemblages and their consequences for paleoenvironmental interpretations of fossil foraminiferal assemblages
Suppression of dilepton production at finite baryon density
We study dilepton production from a quark-gluon plasma of given energy density at finite quark chemical potential μ and find that the dilepton production rate is a strongly decreasing function of μ. Therefore, the signal to background ratio of dileptons from a plasma created in a heavy-ion collision may decrease significantly
A near-infrared/optical/X-ray survey in the centre of sigma Orionis
Because of the intense brightness of the OB-type multiple star system sigma
Ori, the low-mass stellar and substellar populations close to the centre of the
very young sigma Orionis cluster is poorly know. I present an IJHKs survey in
the cluster centre, able to detect from the massive early-type stars down to
cluster members below the deuterium burning mass limit. The near-infrared and
optical data have been complemented with X-ray imaging. Ten objects have been
found for the first time to display high-energy emission. Previously known
stars with clear spectroscopic youth indicators and/or X-ray emission define a
clear sequence in the I vs. I-Ks diagram. I have found six new candidate
cluster members that follow this sequence. One of them, in the magnitude
interval of the brown dwarfs in the cluster, displays X-ray emission and a very
red J-Ks colour, indicative of a disc. Other three low-mass stars have excesses
in the Ks band as well. The frequency of X-ray emitters in the area is 80+/-20
%. The spatial density of stars is very high, of up to 1.6+/-0.1 arcmin-2.
There is no indication of lower abundance of substellar objects in the cluster
centre. Finally, I also report two cluster stars with X-ray emission located at
only 8000-11000 AU to sigma Ori AB, two sources with peculiar colours and an
object with X-ray emission and near-infrared magnitudes similar to those of
previously-known substellar objects in the cluster.Comment: Accepted for publication in Astron. Nachr. It has not been edited for
language ye
Evaluation of the statutory surveillance system for invasive MRSA infections in Germany, 2016–2017
Background: Mandatory notification of invasive methicillin-resistant Staphylococcus aureus (MRSA) infections was introduced for laboratories in Germany in 2009. The aims were to support local health authorities (LHAs) in their mandate to prevent and control infections in hospitals and to improve population-based nationwide surveillance of healthcare associated infections. We evaluated the MRSA surveillance system to assess whether its aims were met and to identify areas for improvement.
Methods:Using the updated guidelines for evaluating public health surveillance systems by the Centers for Disease Control and Prevention we assessed the attributes simplicity, timeliness, data quality, acceptability, and usefulness. In 2016/2017 we interviewed staff in LHAs, state health authorities (SHAs), and laboratories and analyzed surveillance data of cases notified between 2009 and 2016.
Results:We interviewed 10% of LHAs (n = 38), 63% of SHAs (n = 10), 5 selected laboratories and analyzed information on 27,706 notified MRSA cases. LHAs reported that on receiving notifications from laboratories they contacted hospitals for clinical information, which was time-consuming and complicated as physicians were hard to reach or refused to answer questions, citing doctor-patient confidentiality. LHAs suggested reducing the amount of information collected as some clinical information was unnecessary for implementing control measures. LHAs stated that they received notifications on time, however surveillance data analysis showed some delay. Data completeness exceeded 90% for most variables, however it was only 68% and 80% for dates of disease onset and hospital admission respectively making it impossible to discriminate between hospital and community acquired infections in half of the cases. The surveillance system was well accepted by half of the interviewees. A third however stated that the benefits of the surveillance system were outweighed by the work associated with it. The majority rated the system to be useful for recognizing trends in the MRSA incidence and the ability to check up on infection control measures in hospitals.
Conclusions:The surveillance system proved to be useful by fulfilling its aims. It was timely, acceptable and provided complete data for most variables. However, the system was complicated; ensuring that only relevant variables are reported could simplify the system without losing any of its usefulness.Peer Reviewe
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