253 research outputs found
Structure and diversity of shallow soft-bottom benthic macrofauna in the Gulf of Lions (NW Mediterranean).
14 pĂĄginas, 10 figuras, 4 tablas.Samples of soft-sediment macrobenthos from
92 sites between 10 and 50 m depth were used to assess (1)
the main soft-bottom macrofauna communities in the Gulf
of Lions, (2) the different components of the diversity of
benthic macrofauna in this area, and (3) the relevance of
the use of major taxonomic groups as surrogates for the
analysis of the structure and diversity of total macrofauna.
Three main communities were identiïŹed by cluster analysis
and associated procedures. These communities corresponded well to the assemblages recently identiïŹed on the
basis of polychaete composition. The a-diversity indices
were in accordance with those reported for similar communities in the Mediterranean. Conversely, the b-diversity
value was higher than the few other data available in the
literature for marine soft-bottom macrofauna. The total
number of species in the studied area estimated by the
ââtotal species accumulation curveââ (TS) method was
2,319, which was only 10% higher than the number
obtained by extrapolation of the speciesâarea curve. The
similarity matrix based on polychaetes correlated best with
the one based on total macrofauna. Polychaetes and crustaceans were also the best surrogates of total macrofauna
when assessing a-diversity (except in the case of D*).
Conversely, molluscs were the best surrogates of total
macrofauna b-diversity. Our results show that the choice of
an optimal surrogate for total benthic macrofauna depends
on the characteristic of the benthic macrofauna to be
studied. Moreover, this choice is also dependent on the
environment to be studiedThis work is part of the PhD thesis of CeÂŽline
Labrune. It was carried out within the EC Network of Excellence
MARBEF. CeÂŽline Labrune was supported by the SYSCOLAG project
run by the ReÂŽgion Languedoc-Roussillon.Peer reviewe
A survey on parallel and distributed Multi-Agent Systems
International audienceSimulation has become an indispensable tool for researchers to explore systems without having recourse to real experiments. Depending on the characteristics of the modeled system, methods used to represent the system may vary. Multi-agent systems are, thus, often used to model and simulate complex systems. Whatever modeling type used, increasing the size and the precision of the model increases the amount of computation, requiring the use of parallel systems when it becomes too large. In this paper, we focus on parallel platforms that support multi-agent simulations. Our contribution is a survey on existing platforms and their evaluation in the context of high performance computing. We present a qualitative analysis, mainly based on platform properties, then a performance comparison using the same agent model implemented on each platform
Abundance of Delta Resonances in 58Ni+58Ni Collisions between 1 and 2 AGeV
Charged pion spectra measured in 58Ni-58Ni collisions at 1.06, 1.45 and 1.93
AGeV are interpreted in terms of a thermal model including the decay of Delta
resonances. The transverse momentum spectra of pions are well reproduced by
adding the pions originating from the Delta-resonance decay to the component of
thermal pions, deduced from the high transverse momentum part of the pion
spectra. About 10 and 18% of the nucleons are excited to Delta states at
freeze-out for beam energies of 1 and 2 AGeV, respectively.Comment: 14 pages, LaTeX with 3 included figures; submitted to Physics Letters
Stopping and Radial Flow in Central 58Ni + 58Ni Collisions between 1 and 2 AGeV
The production of charged pions, protons and deuterons has been studied in
central collisions of 58Ni on 58Ni at incident beam energies of 1.06, 1.45 and
1.93 AGeV. The dependence of transverse-momentum and rapidity spectra on the
beam energy and on the centrality of the collison is presented. It is shown
that the scaling of the mean rapidity shift of protons established for AGS and
SPS energies is valid down to 1 AGeV. The degree of nuclear stopping is
discussed; the IQMD transport model reproduces the measured proton rapidity
spectra for the most central events reasonably well, but does not show any
sensitivity between the soft and the hard equation of state (EoS). A radial
flow analysis, using the midrapidity transverse-momentum spectra, delivers
freeze-out temperatures T and radial flow velocities beta_r which increase with
beam energy up to 2 AGeV; in comparison to existing data of Au on Au over a
large range of energies only beta_r shows a system size dependence
Concurrent sampling of transitional and coastal waters by Diffusive Gradient in Thin-films (DGT) and spot sampling for trace metals analysis
This protocol was developed based on the knowledge acquired in the framework of the Interreg MONITOOL project (EAPA_565/2016) where extensive sampling campaigns were performed in transitional and coastal waters covering eight European countries. It provides detailed procedures and guidelines for the sampling of these waterbodies by concurrent collection of discrete water samples and the deployment of Diffusive Gradient in Thin-films (DGT) passive samplers for the measurement of trace metal concentrations. In order to facilitate the application of this protocol by end-users, it presents steps to follow in the laboratory prior to sampling campaigns, explains the procedures for field campaigns (including in situ measurement of supporting parameters) and subsequent sample processing in the laboratory in preparation for trace metal analyze by inductively coupled plasma-mass spectrometry (ICP-MS) and voltammetry. The protocol provides a systematic, coherent field sampling and sample preparation strategy that was developed in order to ensure comparability and reproducibility of the data obtained from each project Partner in different regions. âą Standardization of the concurrent sampling of transitional and coastal waters by DGT passive samplers and spot sampling. âą Robust procedures and tips based on existing international standards and comprehensive practical experience. âą Links to demonstration videos produced within the MONITOOL project
Assessing variability in the ratio of metal concentrations measured by DGT-type passive samplers and spot sampling in European seawaters
The current study evaluates the effect of seawater physico-chemical characteristics on the relationship between the concentration of metals measured by Diffusive Gradients in Thin films (DGT) passive samplers (i.e., DGT-labile concentration) and the concentrations measured in discrete water samples. Accordingly, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure the total dissolved metal concentrations in the discrete water samples and the labile metal concentrations obtained by DGT samplers; additionally, lead and cadmium conditional labile fractions were determined by Anodic Stripping Voltammetry (ASV) and total dissolved nickel was measured by Cathodic Stripping Voltammetry (CSV). It can be concluded that, in general, the median ratios of DGT/ICP and DGT/ASV(CSV) were lower than 1, except for Ni (median ratio close to 1) and Zn (higher than 1). This indicates the importance of speciation and time-integrated concentrations measured using passive sampling techniques, which is in line with the WFD suggestions for improving the chemical assessment of waterbodies. It is the variability in metal content in waters rather than environmental conditions to which the variability of the ratios can be attributed. The ratios were not significantly affected by the temperature, salinity, pH, oxygen, DOC or SPM, giving a great confidence for all the techniques used. Within a regulatory context such as the EU Water Framework Directive this is a great advantage, since the simplicity of not needing to use corrections to minimize the effects of environmental variables could help in implementing DGTs within monitoring networks
Evaluation of the impact of pharmaceutical trainings and tools on the proper use of medicines in pediatrics
Introduction: After six years of medication errorsâ (MEs) collection and analysis in a pediatric unit of a French University Hospital, the number of MEs was no longer decreasing. We then decided to set up pharmaceutical training and tools and evaluate their impact on the occurrence of ME.Materials and methods: This monocentric prospective study was carried out in the form of audits of prescriptions, preparations, and administrations before and after intervention (A1 and A2). After the analysis of A1 results, feedback was given to the teams, some tools for the proper use of medication (PUM) were distributed, and A2 was conducted. Finally, A1 and A2 results were compared.Results: Each audit included 202 observations. A total of 120 MEs were identified during A1 and 54 for A2 (p < 0.0001). The observation rate with at least 1 ME decreased from 39.11% to 21.29% (p < 0.0001), and no observation had more than two MEs during A2 in contrast to A1 (n = 12). Human factors were responsible for the majority of MEs. The audit feedback allowed professionals to feel concerned about ME. The PUM tools received an average satisfaction rating of 9/10. The staff had never participated in this type of training, and all felt it was useful to apply PUM.Conclusion: This study showed a significant impact of pharmaceutical training and tools on the pediatric PUM. Clinical pharmaceutic actions allowed us to reach our objectives and satisfied all the staff. They must, therefore, be continued to limit human factorsâ impact and thus contribute to the safety of drug management in pediatrics
K^+ production in the reaction at incident energies from 1 to 2 AGeV
Semi-inclusive triple differential multiplicity distributions of positively
charged kaons have been measured over a wide range in rapidity and transverse
mass for central collisions of Ni with Ni nuclei. The transverse
mass () spectra have been studied as a function of rapidity at a beam
energy 1.93 AGeV. The distributions of K^+ mesons are well described by a
single Boltzmann-type function. The spectral slopes are similar to that of the
protons indicating that rescattering plays a significant role in the
propagation of the kaon. Multiplicity densities have been obtained as a
function of rapidity by extrapolating the Boltzmann-type fits to the measured
distributions over the remaining phase space. The total K^+ meson yield has
been determined at beam energies of 1.06, 1.45, and 1.93 AGeV, and is presented
in comparison to existing data. The low total yield indicates that the K^+
meson can not be explained within a hadro-chemical equilibrium scenario,
therefore indicating that the yield does remain sensitive to effects related to
its production processes such as the equation of state of nuclear matter and/or
modifications to the K^+ dispersion relation.Comment: 24 pages Latex (elsart) 7 PS figures to be submitted to Nucl. Phys
Long-term (1998â2010) large-scale comparison of the ecological quality status of gulf of lions (NW Mediterranean) benthic habitats
12 pĂĄginas, 4 tablas, 8 figuras.A comprehensive Mediterranean data set has been used to address 3 questions associated with the use of sensitivity/tolerance
based biotic indices to infer the Ecological Quality status (EcoQs) of benthic habitats. Our results
showed: (1) a significant effect of the reference database on derived sensitivity/tolerance measure (ES500.05) as
well as associated Benthic Quality Index values and derived EcoQs; (2) a lack of correlation neither between BQI
and AZTI Marine Biotic Index values nor between BQI and Multivariate-AZTI Marine Biotic Index values; (3) a lack
of correlation between the values of the Benthic Habitat Quality Index (index derived from Sediment Profile Imagery)
and those of either of the 3 tested biotic indices; and (4) a general agreement between the 3 tested biotic
indices in describing the lack of global trend for the EcoQs of the Gulf of Lions despite the occurrence of significant
changes in benthic macrofauna composition between 1998 and 2010.This study has been carried out with financial support from the French National
Research Agency (ANR) in the frame of the Investments for the future
Programme, within the Cluster of Excellence COTE (ANR-10-LABX-45).Peer reviewe
Severe gastric variceal haemorrhage due to splenic artery thrombosis and consecutive arterial bypass
<p>Abstract</p> <p>Background</p> <p>Upper gastrointestinal haemorrhage is mainly caused by ulcers. Gastric varicosis due to portal hypertension can also be held responsible for upper gastrointestinal bleeding. Portal hypertension causes the development of a collateral circulation from the portal to the caval venous system resulting in development of oesophageal and gastric fundus varices. Those may also be held responsible for upper gastrointestinal haemorrhage.</p> <p>Case presentation</p> <p>In this study, we describe the case of a 69-year-old male with recurrent severe upper gastrointestinal bleeding caused by arterial submucosal collaterals due to idiopathic splenic artery thrombosis. The diagnosis was secured using endoscopic duplex ultrasound and angiography. The patient was successfully treated with a laparoscopic splenectomy and complete dissection of the short gastric arteries, resulting in the collapse of the submucosal arteries in the gastric wall. Follow-up gastroscopy was performed on the 12<sup>th </sup>postoperative week and showed no signs of bleeding and a significant reduction in the arterial blood flow within the gastric wall. Subsequent follow-up after 6 months also showed no further gastrointestinal bleeding as well as subjective good quality of life for the patient.</p> <p>Conclusion</p> <p>Submucosal arterial collaterals must be excluded by endosonography via endoscopy in case of recurrent upper gastrointestinal bleeding. Laparoscopic splenectomy provides adequate treatment in preventing any recurrent bleeding, if gastric arterial collaterals are caused by splenic artery thrombosis.</p
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