198,361 research outputs found
Migliaccio Antonio, voce biografica
No full textVoce biografica del pittore garibaldino Antonio Migliaccio, d'origine calabrese, attivo a Napoli e in Calabri
Evidence for organ-specific stem cell microenvironments.
No full textThe X-linked Gata1(low) mutation in mice induces strain-restricted myeloproliferative disorders characterized by extramedullary hematopoiesis in spleen (CD1 and DBA/2) and liver (CD1 only). To assess the role of the microenvironment in establishing this myeloproliferative trait, progenitor cell compartments of spleen and marrow from wild-type and Gata1(low) mice were compared. Phenotype and clonal assay of non-fractionated cells indicated that Gata1(low) mice contain progenitor cell numbers 4-fold lower and 10-fold higher than normal in marrow and spleen, respectively. However, progenitor cells prospectively isolated from spleen, but not from marrow, of Gata1(low) mice expressed colony-forming function in vitro. Therefore, calculation of cloning activity of purified cells demonstrated that the total number of Gata1(low) progenitor cells was 10- to 100-fold lower than normal in marrow and >1,000 times higher than normal in spleen. This observation indicates that Gata1(low) hematopoiesis is favored by the spleen and is in agreement with our previous report that removal of this organ induces wild-type hematopoiesis in heterozygous Gata1(low/+) females (Migliaccio et al., 2009, Blood 114:2107). To clarify if rescue of wild-type hematopoiesis by splenectomy prevented extramedullary hematopoiesis in liver, marrow cytokine expression profile and liver histopathology of splenectomized Gata1(low/+) females were investigated. After splenectomy, the marrow expression levels of TGF-beta, VEGF, osteocalcin, PDGF-alpha, and SDF-1 remained abnormally high while Gata1(low) hematopoiesis was detectable in liver of both CD1 and DBA/2 mutants. Therefore, in the absence of the spleen, Gata1(low) hematopoiesis is supported by the liver suggesting that treatment of myelofibrosis in these animals requires the rescue of both stem cell and microenvironmental functions
A Study on the Electromagnetic Backscattering from Wind-Roughened Water Surfaces
No full textIn this paper we report the results of a study regarding the backscattering from wind-roughened water surfaces. The reference profile data has been deducted by an experiment held at the University of Heidelberg circular wave tank facility. The scattering theory is based on a fractal description of the surface and a combined use of the Kirchhoff approximation and the small perturbation method (SPM). The scattering results are tested versus the ones obtained via the periodic-surface moment method. The study shows the reliability of the novel approach
Strumenti finanziari partecipativi
No full textIl contributo descrive e analizza gli strumenti finanziari partecipativi, quali strumenti di finanziamento che hanno alterato la storica dicotomia tra conferimento-azione-costituzione di capitale di rischio vs. prestito ex mutuo-obbligazione-costituzione di capitale di debito
Cosmic microwave background cosmology with Planck
No full textPlanck is the third-generation space mission aimed at measuring the
cosmic microwave background radiation, a relic of the hot Big Bang.
Planck ultimate measurement of temperature fluctuations in the cosmic
microwave background, together with its leading edge observations of
polarization, allowed us to perform unprecedented tests of the
cosmological model and derive stringent constraints of fundamental
physics. The high sensitivity data also enabled us to obtain the most
significant measurement to date of the gravitational lensing of the
cosmic microwave background. This represents a novel observable for
exploring thirteen billion years of structure formation in the universe.
In the paper, I discuss some of the main cosmological constraints we
obtained so far and their implications for the standard model of
cosmology. I also highlight several key aspects in the data analysis
process
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