92 research outputs found
Lossless compact histogram representation for multi-component images: application to histogram equalization
The problem of histogram representation is addressed. In the case of multi-component images, this problem is not trivial: the theoretical "naive" required memory space goes exponentially beyond todays technical capacities. To overcome this problem, we present a lossless compact representation of vector histograms. It is based on the use of a space filling curve to index the data space. The application of this representation to vector histogram equalization is then considered
Experimental Determination of Phase Equilibria and Occupancies for CO2, CH4, and N2 Hydroquinone Clathrates
Hydroquinone (HQ) forms organic clathrates in the presence of various gas molecules in specific thermodynamic conditions. For some systems, clathrate phase equilibrium and occupancy data are very scarce or inexistent in literature to date. This work presents experimental results obtained for the CO2âHQ, CH4âHQ, and N2âHQ clathrates, in an extended range of temperature from about 288 to 354 K. Formation/dissociation pressures, and occupancies at the equilibrium clathrate forming conditions, were determined for these systems. Experiments showing the influence of the crystallization solvent, and the effect of the gas pressure on HQ solubility, were also presented and discussed. A good agreement is obtained between our experimental results and the already published experimental and modeling data. Our results show a clear dependency of the clathrate occupancy with temperature. The equilibrium curves obtained for CO2âHQ and CH4âHQ clathrates were found to be very close to each other. The results presented in this study, obtained in a relatively large temperature range, are new and important to the field of organic clathrates with potential impact on gas separation, energy storage, and transport
An Italian foreign policy of religious engagement: challenges and prospects
A new awareness of the role of religion in international relations has started to inform concrete policy discussions in several Western Ministries of Foreign Affairs under the heading of âreligious engagementâ in foreign policy. Italy is no exception, but as the country which hosts the Holy See, it represents a special case. As the approach to religion found in the historical record of Italian foreign policy shows, Italy has a comparative advantage and could well develop a unique model of religious engagement by strengthening the central structures involved in religious matters and foreign policy, as well as by using the vast network of Rome-based religious non-state actors as a forum of consultation and policy advice
Spallation reactions. A successful interplay between modeling and applications
The spallation reactions are a type of nuclear reaction which occur in space
by interaction of the cosmic rays with interstellar bodies. The first
spallation reactions induced with an accelerator took place in 1947 at the
Berkeley cyclotron (University of California) with 200 MeV deuterons and 400
MeV alpha beams. They highlighted the multiple emission of neutrons and charged
particles and the production of a large number of residual nuclei far different
from the target nuclei. The same year R. Serber describes the reaction in two
steps: a first and fast one with high-energy particle emission leading to an
excited remnant nucleus, and a second one, much slower, the de-excitation of
the remnant. In 2010 IAEA organized a worskhop to present the results of the
most widely used spallation codes within a benchmark of spallation models. If
one of the goals was to understand the deficiencies, if any, in each code, one
remarkable outcome points out the overall high-quality level of some models and
so the great improvements achieved since Serber. Particle transport codes can
then rely on such spallation models to treat the reactions between a light
particle and an atomic nucleus with energies spanning from few tens of MeV up
to some GeV. An overview of the spallation reactions modeling is presented in
order to point out the incomparable contribution of models based on basic
physics to numerous applications where such reactions occur. Validations or
benchmarks, which are necessary steps in the improvement process, are also
addressed, as well as the potential future domains of development. Spallation
reactions modeling is a representative case of continuous studies aiming at
understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie
The GUINEVERE Project for Accelerator Driven System Physics
paper 9414International audienceThe GUINEVERE project is part of the EUROTRANS Integrated Project of the 6th EURATOM Framework Programme. It is mainly devoted to ADS on-line reactivity monitoring validation, sub-criticality determination and operational procedures (loading, start-up, shut-down, ...) as a follow-up of the MUSE experiments. The project consists in coupling a fast lead core, set-up in the VENUS reactor at SCK*CEN Mol (B), with a GENEPI neutron source under construction by CNRS. To accommodate the accelerator in a vertical coupling configuration, the VENUS building is being heightened. The fast core will be loaded with enriched Uranium and will be moderated and reflected with solid lead (zero power experiment). For the purpose of the experimental programme, the neutron source has to be operated not only in pulsed mode but also in continuous mode to investigate the current-to-flux reactivity indicator in representative conditions of a powerful ADS. In this latter mode it is also required to make short beam interruptions to have access to the neutron population decrease as a function of time: from this spectrum it will be possible to apply different analysis techniques such as "prompt decay" fitting techniques and "source jerk" techniques. Beam interruptions will be repeated at a programmable frequency to improve time spectra statistics. Different sub-criticality levels (keff=0.99, 0.97, 0.95, ...) will be investigated in order to obtain a full set of data points for the final overall validation of the methodology. This paper describes the status of the experimental facility assembling, and the foreseen experimental programme to be started
A Spontaneous Mutation of the Rat Themis Gene Leads to Impaired Function of Regulatory T Cells Linked to Inflammatory Bowel Disease
Spontaneous or chemically induced germline mutations, which lead to Mendelian phenotypes, are powerful tools to discover new genes and their functions. Here, we report an autosomal recessive mutation that occurred spontaneously in a Brown-Norway (BN) rat colony and was identified as causing marked T cell lymphopenia. This mutation was stabilized in a new rat strain, named BNm for âBN mutated.â In BNm rats, we found that the T cell lymphopenia originated in the thymus, was intrinsic to CD4 T lymphocytes, and was associated with the development of an inflammatory bowel disease. Furthermore, we demonstrate that the suppressive activity of both peripheral and thymic CD4+ CD25bright regulatory T cells (Treg) is defective in BNm rats. Complementation of mutant animals with BN Treg decreases disease incidence and severity, thus suggesting that the impaired Treg function is involved in the development of inflammatory bowel disease in BNm rats. Moreover, the cytokine profile of effector CD4 T cells is skewed toward Th2 and Th17 phenotypes in BNm rats. Linkage analysis and genetic dissection of the CD4 T cell lymphopenia in rats issued from BNmĂDA crosses allowed the localization of the mutation on chromosome 1, within a 1.5 megabase interval. Gene expression and sequencing studies identified a frameshift mutation caused by a four-nucleotide insertion in the Themis gene, leading to its disruption. This result is the first to link Themis to the suppressive function of Treg and to suggest that, in Themis-deficient animals, defect of this function is involved in intestinal inflammation. Thus, this study highlights the importance of Themis as a new target gene that could participate in the pathogenesis of immune diseases characterized by chronic inflammation resulting from a defect in the Treg compartment
International migration and the rise of the âcivilâ nation
This is an Accepted Manuscript of an article published in Journal of Ethnic and Migration Studies on 2 March 2016, available online: http://www.tandfonline.com/10.1080/1369183X.2016.1155980Scholars largely agree that immigration policies in Western Europe have switched to a liberal, civic model. Labelled as âcivic turnâ, âcivic integrationâ or âliberal convergenceâ, this model is not identically applied across countries, since national institutions, traditions and identifications still matter. Even so, the main focus is on processes which allow or prevent migrants to be incorporated into nations usually taken for granted in their meanings. Moving from policies to discourses, this article aims to interrogate what kind of nation is behind these policies as a way to further scrutinise the âcivic turnâ. Exploring how the term âcivilityâ and its adjectivisations are discursively deployed in Italian parliamentary debates on immigration and integration issues, the article points to two opposite narratives of nation. While one mobilises civility in order to rewrite the nation in terms of a common, inclusive, civic âweâ, the other uses civility to reaffirm the conflation between national identity and the identity of the ethno-cultural majority. These findings suggest the importance of exploring the âcivic turnâ not only across countries, but also across political parties within the same country to capture the ways in which a liberal, civic convergence in political discourses might hide divergent national boundary mechanisms
Decreased levels of serum soluble HLA class I antigens in HLAâB27 positive spondyloarthropathies
International audienc
In target yields for EURISOL RIB production
The goal of this paper is the estimation of the in-target neutron-induced fission fragment productions using the most recent optimized design of the EURISOL converter-fission target assembly.Submitted to EPJA
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