27 research outputs found

    A Lattice Boltzmann Method for relativistic rarefied flows in (2+1) dimensions

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    We propose an extension to recently developed Relativistic Lattice Boltzmann solvers (RLBM), which allows the simulation of flows close to the free streaming limit. Following previous works AmbruĹź and Blaga (2018), we use product quadrature rules and select weights and nodes by separately discretizing the radial and the angular components. This procedure facilitates the development of quadrature-based RLBM with increased isotropy levels, thus improving the accuracy of the method for the simulation of flows beyond the hydrodynamic regime. In order to quantify the improvement of this discretization procedure over existing methods, we perform numerical tests of shock waves in one and two spatial dimensions in various kinetic regimes across the hydrodynamic and the free-streaming limits.</p

    Searching for galaxy-scale strong-lenses in galaxy clusters with deep networks -- I: methodology and network performance

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    Galaxy-scale strong lenses in galaxy clusters provide a unique tool to investigate their inner mass distribution and the sub-halo density profiles in the low-mass regime, which can be compared with the predictions from cosmological simulations. We search for galaxy-galaxy strong-lensing systems in HST multi-band imaging of galaxy cluster cores from the CLASH and HFF programs by exploring the classification capabilities of deep learning techniques. Convolutional neural networks are trained utilising highly-realistic simulations of galaxy-scale strong lenses injected into the HST cluster fields around cluster members. To this aim, we take advantage of extensive spectroscopic information on member galaxies in 16 clusters and the accurate knowledge of the deflection fields in half of these from high-precision strong lensing models. Using observationally-based distributions, we sample magnitudes, redshifts and sizes of the background galaxy population. By placing these sources within the secondary caustics associated with cluster galaxies, we build a sample of ~3000 galaxy-galaxy strong lenses which preserve the full complexity of real multi-colour data and produce a wide diversity of strong lensing configurations. We study two deep learning networks processing a large sample of image cutouts in three HST/ACS bands, and we quantify their classification performance using several standard metrics. We find that both networks achieve a very good trade-off between purity and completeness (85%-95%), as well as good stability with fluctuations within 2%-4%. We characterise the limited number of false negatives and false positives in terms of the physical properties of the background sources and cluster members. We also demonstrate the neural networks' high degree of generalisation by applying our method to HST observations of 12 clusters with previously known galaxy-scale lensing systems.Comment: 17 pages, 13 figures, to be published on A&

    Seroprevalence of five neglected parasitic diseases among immigrants accessing five infectious and tropical diseases units in Italy: a cross-sectional study.

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    : This multicentre cross-sectional study aims to estimate the prevalence of five neglected tropical diseases (Chagas disease, filariasis, schistosomiasis, strongyloidiasis, toxocariasis) among immigrants accessing health care facilities in five Italian cities (Bologna, Brescia, Florence, Rome, Verona). : Individuals underwent a different set of serological tests, according to country of origin and presence of eosinophilia. Seropositive patients were treated and further followed up. : A total of 930 adult immigrants were enrolled: 477 men (51.3%), 445 women (47.9%), 8 transgender (0.8%); median age was 37.81 years (range 18-80). Most of them were coming from the African continent (405/930, 43.5%), the rest from East Europe, South America and Asia. A portion of 9.6% (89/930) were diagnosed with at least one of the infections under study. Seroprevalence of each specific infection varied from 3.9% (7/180) for Chagas diseases to 9.7% (11/113) for toxocariasis. Seropositive people were more likely to be 35 to 40 years-old male and to come from South East Asia, Sub-Saharan Africa or South America. : The results of our study confirm that neglected tropical diseases represent a substantial health problem among immigrants and highlight the need for addressing this emerging public health issue.<br/

    Zwischen Lexik und Hermenutik. Die Realien als Orientierungspunkte

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    Il passaggio da un'attenta valutazione della traducibilit\ue0 in potenza e in atto degli aspetti lessicali, legati all'affascinante mondo dei Realia - non di rado identificati con gli intraducibili tout court - alla complessa e di fatto inesauribile geografia delle isotopie che strutturano i testi permette di recuperare ampliandolo il concetto di ermeneutica applicato alla traduzione letteraria. La dimensione ermeneutica si impone di prepotenza innnestata su un tessuto di parole che al di l\ue0 della dimensione referenziale sono caricate di una connotativit\ue0 pervasiva e non esclusivamente autoriale

    A Lattice Boltzmann Method for relativistic rarefied flows in (2+1) dimensions

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    We propose an extension to recently developed Relativistic Lattice Boltzmann solvers (RLBM), which allows the simulation of flows close to the free streaming limit. Following previous works AmbruĹź and Blaga (2018), we use product quadrature rules and select weights and nodes by separately discretizing the radial and the angular components. This procedure facilitates the development of quadrature-based RLBM with increased isotropy levels, thus improving the accuracy of the method for the simulation of flows beyond the hydrodynamic regime. In order to quantify the improvement of this discretization procedure over existing methods, we perform numerical tests of shock waves in one and two spatial dimensions in various kinetic regimes across the hydrodynamic and the free-streaming limits

    Anticoagulante lupico, anticorpi anticardiolipina e trombosi polmonare fatale.

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    descrizione di un caso di trombosi polmonare fatale in un soggetto con doppia positivitĂ  per anticorpi anti-fosfolipidi e lupus anticoagulan

    Fast kinetic simulator for relativistic matter

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    Relativistic kinetic theory is ubiquitous to several fields of modern physics, finding application at large scales in systems in astrophysical contexts, all of the way down to subnuclear scales and into the realm of quark–gluon plasmas. This motivates the quest for powerful and efficient computational methods that are able to accurately study fluid dynamics in the relativistic regime as well as the transition to beyond hydrodynamics—in principle all of the way down to ballistic regimes. We present a family of relativistic lattice kinetic schemes for the efficient simulation of relativistic flows in both strongly (fluid) and weakly (rarefied gas) interacting regimes. The method can deal with both massless and massive particles, thereby encompassing ultra- and mildly relativistic regimes alike. The computational performance of the method for the simulation of relativistic flows across the aforementioned regimes is discussed in detail, along with prospects of future applications

    Il quadro ematologico dell'artrite reumatoide del beta-talassemico eterozigote

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    lo sudio analizza il quadro ematologico con particolare riferimento allo stato anemico di soggetti beta talassemici eterozigoti nel contesto dell'artrite reumatoide

    Pyrazole Related Nucleosides 5. Synthesis and Biological Activity of 2’-Deoxy- 2’, 3’-Dideoxy- and Acyclo-Analogues of 4-Iodo-1-beta-D-Ribofuranosyl-3-Carboxymethyl Pyrazole (IPCAR).

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    Continuing our studies on the structure-activity relationships (SAR) of 4-iodo-1-beta-D-ribofuranosyl-3-carboxymethyl pyrazole (IPCAR), the ribofuranosyl moiety has been substituted with acyclic chains, namely 1-[(2-hydroxyethoxy)methyl]- and 1-[(1,3-dihydroxy-2-propoxy)methyl]-pyrazole derivatives (4, 5 and 8, 9 respectively), with the 2'-deoxy-beta-D-ribofuranosyl group (12 and 13) and finally with the 2',3'-dideoxy-D-glycero-pentofuranosyl-moiety (16 and 17). None of the new compounds display any interesting biological activity

    Pyrazole-related nucleosides .4. Synthesis and antitumor activity of some 1-tetrahydropyranyl-4-substituted pyrazoles

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    Continuing our studies on the structure-activity relationships of some pyrazole nucleosides (1a-h) structurally related to ribavirin, tiazofurin and selenazofurin, we describe here the synthesis and antitumor/antiviral/antimicrobial activity of a new series of 1-tetrahydropyranyl-4-substituted pyrazoles. In this study, the tetrahydropyranyl moiety (THP), designed as a mimic of the glycosidic portion of the parent compounds 1a-h, has led to a few derivatives with moderate cytotoxic activity against leukemia/lymphoma and solid tumor-derived cell lines (IC50 14-100 microM). The compounds obtained through substitution of the ribofuranosyl moiety by the THP moiety were still active, the free heterocyclic bases were devoid of any activity
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