37 research outputs found

    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/

    PATOLOGIA DEGENERATIVA DEL GOMITO. IL MICROTRAUMA.

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    Dopo una sezione dedicata alla anatomia del gomito, vengono analizzati i quadri clinici e radiologici secondari alla patologia da iperuso. Un approfondimento particolare è dedicato al gomito nella DISH ed alle alterazioni dovute ai microtraumatismi di origine professionale

    Osservazioni sull'anemia in corso di artropatia psoriasica.

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    E' stato sudiatoil quadro ematologico periferico di 70 pazienti affetti da artrite psoriasica. L'anemia è meno frequente (28% dei casi) di quanto riportato nell'artrite reumatoide. La maggior parte dei soggetti anemici con artrite psoriasica presentava un impegno poliarticolare simil-reumatoide

    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 positività per anticorpi anti-fosfolipidi e lupus anticoagulan

    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

    Synthetic approaches to a mononucleotide prodrug of cytarabine.

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    Synthetic pathways to a mononucleotide prodrug of cytarabine (Ara-C) bearing S-pivaloyl-2-thioethyl (tBuSATE) groups, as biolabile phosphate protections, are reported. Using a common phosphoramidite approach, two different kinds of nucleoside protecting groups have been investigated. During this study, we obsd. an intermol. migration of the Boc protecting group in the course of the tert-butyldimethylsilyl ether cleavage using tetra-Bu ammonium fluorid
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