40 research outputs found
Effects of spoilage on nitrogen and carbon stable isotopes signatures of the clam Ruditapes decussatus
Fish and seafood products are highly susceptible to post-mortem
spoilage due to autolytic reactions at start, then microbiological activity and
eventually oxidative reactions. Chemical and microbiological parameters are
usually used to assess quality and make decisions for protecting public health,
but they lack precision in defining which spoilage pathway is occurring at each
moment. The objective of this work was to assess the effects of spoilage reactions
on nitrogen and carbon stable isotopes in the grooved carpet shell clam,
Ruditapes decussatus, and compare them to biochemical indicators of seafood
deterioration, in order to better understand the relations between the different
spoilage pathways during commercial storage conditions. Clams were kept in a
refrigerator at 5 ºC, to simulate normal commercial storage conditions, and
sampled in the beginning of the experiment, and after eight, ten and twelve
days. Moisture, condition index, percentage edibility, total volatile basic nitrogen
(TVB-N), pH, nitrogen and carbon percentages and stable isotopes were determined
for each sampling moment. Stable isotope analyses were performed
using a Costech Elemental Analyzer (ECS 4010) coupled to a ThermoFinnigan
Delta V Advantage. Stable isotopes analysis, especially for nitrogen, proved to
be a good tool for the study of clam deterioration. Nitrogen stable isotopes results
showed a relation with other spoilage indicators, such as pH and TVB-N,
and allowed identifying spoilage specific pathways, such as amino acids decarboxylation
and production of volatile nitrogen compounds.info:eu-repo/semantics/publishedVersio
Quick Ultra-VIolet Kilonova surveyor (QUVIK)
We present a near-UV space telescope on a ~70kg micro-satellite with a
moderately fast repointing capability and a near real-time alert communication
system that has been proposed in response to a call for an ambitious Czech
national mission. The mission, which has recently been approved for Phase 0, A,
and B1 study shall measure the brightness evolution of kilonovae, resulting
from mergers of neutron stars in the near-UV band and thus it shall distinguish
between different explosion scenarios. Between the observations of transient
sources, the satellite shall perform observations of other targets of interest,
a large part of which will be chosen in open competition.Comment: SPIE Astronomical Telescopes and Instrumentatio
Geographic Visualization in Archaeology
Archaeologists are often considered frontrunners in employing spatial approaches within the social sciences and humanities, including geospatial technologies such as geographic information systems (GIS) that are now routinely used in archaeology. Since the late 1980s, GIS has mainly been used to support data collection and management as well as spatial analysis and modeling. While fruitful, these efforts have arguably neglected the potential contribution of advanced visualization methods to the generation of broader archaeological knowledge. This paper reviews the use of GIS in archaeology from a geographic visualization (geovisual) perspective and examines how these methods can broaden the scope of archaeological research in an era of more user-friendly cyber-infrastructures. Like most computational databases, GIS do not easily support temporal data. This limitation is particularly problematic in archaeology because processes and events are best understood in space and time. To deal with such shortcomings in existing tools, archaeologists often end up having to reduce the diversity and complexity of archaeological phenomena. Recent developments in geographic visualization begin to address some of these issues, and are pertinent in the globalized world as archaeologists amass vast new bodies of geo-referenced information and work towards integrating them with traditional archaeological data. Greater effort in developing geovisualization and geovisual analytics appropriate for archaeological data can create opportunities to visualize, navigate and assess different sources of information within the larger archaeological community, thus enhancing possibilities for collaborative research and new forms of critical inquiry
The X-CLASS survey: A catalogue of 1646 X-ray-selected galaxy clusters up to z1.5
International audienceCosmological probes based on galaxy clusters rely on cluster number counts and large-scale structure information. X-ray cluster surveys are well suited for this purpose, since they are far less affected than optical surveys by projection effects, and cluster properties can be predicted with good accuracy. The XMM Cluster Archive Super Survey, X-CLASS, is a serendipitous search of X-ray-detected galaxy clusters in 4176 XMM-Newton archival observations until August 2015. All observations are clipped to exposure times of 10 and 20 ks to obtain uniformity and they span ~269 deg across the high-Galactic latitude sky (). The main goal of the survey is the compilation of a well-selected cluster sample suitable for cosmological analyses. We describe the detection algorithm, the visual inspection, the verification process and the redshift validation of the cluster sample, as well as the cluster selection function computed by simulations. We also present the various metadata that are released with the catalogue, along with the redshifts of 124 clusters obtained with a dedicated multi-object spectroscopic follow-up programme. With this publication we release the new X-CLASS catalogue of 1646 well-selected X-ray-detected clusters over a wide sky area, along with their selection function. The sample spans a wide redshift range, from the local Universe up to z~1.5, with 982 spectroscopically confirmed clusters, and over 70 clusters above z=0.8. Because of its homogeneous selection and thorough verification, the cluster sample can be used for cosmological analyses, but also as a test-bed for the upcoming eROSITA observations and other current and future large-area cluster surveys. It is the first time that such a catalogue is made available to the community via an interactive database which gives access to a wealth of supplementary information, images, and data
The X-CLASS survey: A catalogue of 1646 X-ray-selected galaxy clusters up to similar to 1.5
Context. Cosmological probes based on galaxy clusters rely on cluster
number counts and large-scale structure information. X-ray cluster
surveys are well suited for this purpose because they are far less
affected by projection effects than optical surveys, and cluster
properties can be predicted with good accuracy.Aims. The XMM Cluster
Archive Super Survey, X-CLASS, is a serendipitous search of
X-ray-detected galaxy clusters in 4176 XMM-Newton archival observations
until August 2015. All observations are clipped to exposure times of 10
and 20 ks to obtain uniformity, and they span similar to 269 deg(2)
across the high-Galactic latitude sky (|b| > 20 degrees). The main goal
of the survey is the compilation of a well-selected cluster sample
suitable for cosmological analyses.Methods. We describe the detection
algorithm, the visual inspection, the verification process, and the
redshift validation of the cluster sample, as well as the cluster
selection function computed by simulations. We also present the various
metadata that are released with the catalogue, along with two different
count-rate measurements, an automatic one provided by the pipeline, and
a more detailed and accurate interactive measurement. Furthermore, we
provide the redshifts of 124 clusters obtained with a dedicated
multi-object spectroscopic follow-up programme.Results. With this
publication, we release the new X-CLASS catalogue of 1646 well-selected
X-ray-detected clusters over a wide sky area, along with their selection
function. The sample spans a wide redshift range, from the local
Universe up to z similar to 1.5, with 982 spectroscopically confirmed
clusters, and over 70 clusters above z=0.8. The redshift distribution
peaks at z similar to 0.1, while if we remove the pointed observations
it peaks at z similar to 0.3. Because of its homogeneous selection and
thorough verification, the cluster sample can be used for cosmological
analyses, but also as a test-bed for the upcoming eROSITA observations
and other current and future large-area cluster surveys. It is the first
time that such a catalogue is made available to the community via an
interactive database which gives access to a wealth of supplementary
information, images, and data