292 research outputs found

    Fidarsi o no del ColorChecker?

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    Il ColorChecker \ue8 uno strumento usato nel campo della fotografia digitale per eseguire una calibrazione cromatica. Il pannello composto da 24 tasselli a colori viene inserito all\u2019interno di una fotografia digitale per avere una acquisizione di valori di riferimento noti. L\u2019idea \ue8 quella che conoscendo i valori del ColorChecker e correggendo quelli relativi acquisiti si pu\uf2 calibrare cromaticamente tutta l\u2019immagine. L\u2019obiettivo di questo lavoro \ue8 testare i limiti e l\u2019affidabilit\ue0 dell\u2019uso del ColorChecker. A questo scopo sono state acquisite immagini fotografiche digitali a colori contenenti il ColorChecker a diverse condizioni di illuminazione e distanze dall\u2019obiettivo. Dopo aver corretto le immagini rispetto a un punto di bianco ottenuto dall\u2019apposito tassello del ColorChecker, \ue8 stata valutata la variabilit\ue0 dei tasselli colorati rispetto ai dati di fabbrica. Sono stati inoltre misurati il range dinamico relativo del ColorChecker e la linearit\ue0 dei valori di luminanza dei tasselli in scala di grigi rapportati ai valori corrispondenti dei dati di fabbrica

    Genetic model for the color anomalies at the termination of pegmatitic gem tourmaline crystals from the island of Elba, Italy

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    Tourmaline crystals from the island of Elba commonly display a sharp transition to dark colors at the analogous termination due to the incorporation of Fe and/or Mn during the latest stages of crystallization in pegmatites. The formation of such color anomalies is related to a dramatic physicochemical change in the crystallization environment as a consequence of an opening of the geochemical system. However, mechanisms that may lead to the availability of Fe and/or Mn in the residual cavity fluids have been unclear. On the basis of chemical and spectroscopic investigations, combined with structural and paragenetic observations of the cavities, we propose a general genetic model in which, as a consequence of a pocket rupture event, chemical alteration of Fe- and Mn-rich minerals that formed early in the pegmatitic rock surrounding the cavities occurred through leaching processes, produced by the action of the highly reactive late-stage cavity fluids. Such processes were responsible for the release of Fe and Mn in the geochemical system, allowing the formation of the late-stage dark-colored terminations in the tourmaline crystals. In some cavities, a high availability of Mn and/or Fe determined the evolution of the crystals from an initial elbaite/fluor-elbaite composition to celleriite, foitite or schorl. This compositional evolution trend can be described by the following general chemical substitution: XNa+ + Y(Li1.5 + Al0.5)3+ + WF− ↔ X□ + 2Y(Fe,Mn)2+ + WOH−.</p

    Dysregulation of NIPBL leads to impaired RUNX1 expression and hematopoietic defects

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    The transcription factor RUNX1, a pivotal regulator of HSCs and haematopoiesis, is a frequent target of chromosomal translocations, point mutations or altered gene/protein dosage. These modifications lead or contribute to the development of myelodysplasia, leukaemia or platelet disorders. A better understanding of how regulatory elements contribute to fine-tune the RUNX1 expression in haematopoietic tissues could improve our knowledge of the mechanisms responsible for normal haematopoiesis and malignancy insurgence. The cohesin RAD21 was reported to be a regulator of RUNX1 expression in the human myeloid HL60 cell line and during primitive haematopoiesis in zebrafish. In our study, we demonstrate that another cohesin, NIPBL, exerts positive regulation of RUNX1 in three different contexts in which RUNX1 displays important functions: in megakaryocytes derived from healthy donors, in bone marrow samples obtained from adult patients with acute myeloid leukaemia and during zebrafish haematopoiesis. In this model, we demonstrate that alterations in the zebrafish orthologue nipblb reduce runx1 expression with consequent defects in its erythroid and myeloid targets such as gata1a and spi1b in an opposite way to rad21. Thus, also in the absence of RUNX1 translocation or mutations, additional factors such as defects in the expression of NIPBL might induce haematological diseases

    Hybrid fibroin/polyurethane small-diameter vascular grafts: from fabrication to in vivo preliminary assessment

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    To address the need of alternatives to autologous vessels for small-calibre vascular applications (e.g. cardiac surgery), a bio-hybrid semi-degradable material composed of silk fibroin (SF) and polyurethane (Silkothane (R)) was herein used to fabricate very small-calibre grafts (o(in) = 1.5 mm) via electrospinning. Bio-hybrid grafts were in vitro characterized in terms of morphology and mechanical behaviour, and compared to similar grafts of pure SF. Similarly, two native vessels from a rodent model (abdominal aorta and vena cava) were harvested and characterized. Preliminary implants were performed on Lewis rats to confirm the suitability of Silkothane (R) grafts for small-calibre applications, specifically as aortic insertion and femoral shunt. The manufacturing process generated pliable grafts consisting of a randomized fibrous mesh and exhibiting similar geometrical features to rat aortas. Both Silkothane (R) and pure SF grafts showed radial compliances in the range from 1.37 +/- 0.86 to 1.88 +/- 1.01% 10(-2) mmHg(-1), lower than that of native vessels. The Silkothane (R) small-calibre devices were also implanted in rats demonstrating to be adequate for vascular applications; all the treated rats survived the surgery for three months after implantation, and 16 rats out of 17 (94%) still showed blood flow inside the graft at sacrifice. The obtained results lay the basis for a deeper investigation of the interaction between the Silkothane (R) graft and the implant site, which may deal with further analysis on the potentialities in terms of degradability and tissue formation, on longer time-points

    Gem-Quality Tourmaline from LCT Pegmatite in Adamello Massif, Central Southern Alps, Italy: An Investigation of Its Mineralogy, Crystallography and 3D Inclusions

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    In the early 2000s, an exceptional discovery of gem-quality multi-coloured tourmalines, hosted in Litium-Cesium-Tantalum (LCT) pegmatites, was made in the Adamello Massif, Italy. Gem-quality tourmalines had never been found before in the Alps, and this new pegmatitic deposit is of particular interest and worthy of a detailed characterization. We studied a suite of faceted samples by classical gemmological methods, and fragments were studied with Synchrotron X-ray computed micro-tomography, which evidenced the occurrence of inclusions, cracks and voids. Electron Microprobe combined with Laser Ablation analyses were performed to determine major, minor and trace element contents. Selected samples were analysed by single crystal X-ray diffraction method. The specimens range in colour from colourless to yellow, pink, orange, light blue, green, amber, brownish-pink, purple and black. Chemically, the tourmalines range from fluor-elbaite to fluor-liddicoatite and rossmanite: these chemical changes occur in the same sample and affect the colour. Rare Earth Elements (REE) vary from 30 to 130 ppm with steep Light Rare Earth Elemts (LREE)-enriched patterns and a negative Eu-anomaly. Structural data confirmed the elbaitic composition and showed that high manganese content may induce the local static disorder at the O(1) anion site, coordinating the Y cation sites occupied, on average, by Li, Al and Mn2+ in equal proportions, confirming previous findings. In addition to the gemmological value, the crystal-chemical studies of tourmalines are unanimously considered to be a sensitive recorder of the geological processes leading to their formation, and therefore, this study may contribute to understanding the evolution of the pegmatites related to the intrusion of the Adamello pluton

    The STRIP instrument of the Large Scale Polarization Explorer: microwave eyes to map the Galactic polarized foregrounds

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    In this paper we discuss the latest developments of the STRIP instrument of the "Large Scale Polarization Explorer" (LSPE) experiment. LSPE is a novel project that combines ground-based (STRIP) and balloon-borne (SWIPE) polarization measurements of the microwave sky on large angular scales to attempt a detection of the "B-modes" of the Cosmic Microwave Background polarization. STRIP will observe approximately 25% of the Northern sky from the "Observatorio del Teide" in Tenerife, using an array of forty-nine coherent polarimeters at 43 GHz, coupled to a 1.5 m fully rotating crossed-Dragone telescope. A second frequency channel with six-elements at 95 GHz will be exploited as an atmospheric monitor. At present, most of the hardware of the STRIP instrument has been developed and tested at sub-system level. System-level characterization, starting in July 2018, will lead STRIP to be shipped and installed at the observation site within the end of the year. The on-site verification and calibration of the whole instrument will prepare STRIP for a 2-years campaign for the observation of the CMB polarization.Comment: 17 pages, 15 figures, proceedings of the SPIE Astronomical Telescopes + Instrumentation conference "Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX", on June 15th, 2018, Austin (TX

    Renal progenitors derived from human iPSCs engraft and restore function in a mouse model of acute kidney injury

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    Acute kidney injury (AKI) is one of the most relevant health issues, leading to millions of deaths. The magnitude of the phenomenon remarks the urgent need for innovative and effective therapeutic approaches. Cell-based therapy with renal progenitor cells (RPCs) has been proposed as a possible strategy. Studies have shown the feasibility of directing embryonic stem cells or induced Pluripotent Stem Cells (iPSCs) towards nephrogenic intermediate mesoderm and metanephric mesenchyme (MM). However, the functional activity of iPSC-derived RPCs has not been tested in animal models of kidney disease. Here, through an efficient inductive protocol, we directed human iPSCs towards RPCs that robustly engrafted into damaged tubuli and restored renal function and structure in cisplatin-mice with AKI. These results demonstrate that iPSCs are a valuable source of engraftable cells with regenerative activity for kidney disease and create the basis for future applications in stem cell-based therapy

    NIPBL: a new player in myeloid cells differentiation

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    NUCLEOPHOSMIN1 (NPM1) is the most frequently mutated gene in acute myeloid leukemia. Notably, NPM1 mutations are always accompanied by additional mutations such as those in cohesin genes RAD21, SMC1A, SMC3, STAG2 but not in the cohesin regulator NIPBL. In this work, we analyze a cohort of adult patients with acute myeloid leukemia and NPM1 mutation and we observe specific reduction in the expression of NIPBL but not in other cohesin genes. In our zebrafish model, the overexpression of the mutated form of NPM1 also induced the down-regulation of nipblb, the zebrafish orthologue of the human NIPBL. To investigate the hematopoietic phenotype and the interaction between mutated NPM1 and nipblb, we generate a zebrafish model with nipblb down-regulation that shows an increased number of myeloid progenitors. This phenotype is due to a hyper activation of the canonical Wnt pathway: the rescue of myeloid cells blocked in an undifferentiated state is possible when the Wnt pathway is inhibited by ddk1b mRNA injection or indomethacin administration. Our results reveal for the first time a role for NIPBL during zebrafish hematopoiesis and suggest that NIPBL/NPM1 interplay may regulate myeloid differentiation in zebrafish and humans through the canonical Wnt pathway and that dysregulation of these interactions may drive to leukemic transformations

    Product-service systems evolution in the era of Industry 4.0

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    Funder: Università degli studi di BergamoAbstract: Recent economic transformations have forced companies to redefine their value propositions, increasing traditional product offerings with supplementary services—the so-called Product-Service System (PSS). Among them, the adoption of Industry 4.0 technologies is very common. However, the directions that companies are undertaking to offer new value to their customers in the Industry 4.0 have not yet been investigated in detail. Based on a focus group, this paper contributes to this understanding by identifying the main trajectories that would shape a future scenario in which PSS and Industry 4.0 would merge. In addition, future research directions addressing (a) the transformation of the PSS value chain into a PSS ecosystem, (b) the transformation inside a single company towards becoming a PSS provider, and (c) the digital transformation of the traditional PSS business model are identified
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