495 research outputs found

    Asymptotic symmetries of difference equations on a lattice

    Get PDF

    Allievi interni dell'Istituto di Anatomia umana normale nell'anno accademico 1934-35

    Get PDF
    Comunicazione da parte di Giuseppe Levi degli studenti che hanno frequentato l'Istituto, tra cui figurano Salvatore Luria, Rita Levi (Montalcini) ed Eugenia Sacerdote. - Formato del documento analogico: 2 c

    A network approach for low dimensional signatures from high throughput data

    Get PDF
    : One of the main objectives of high-throughput genomics studies is to obtain a low-dimensional set of observables-a signature-for sample classification purposes (diagnosis, prognosis, stratification). Biological data, such as gene or protein expression, are commonly characterized by an up/down regulation behavior, for which discriminant-based methods could perform with high accuracy and easy interpretability. To obtain the most out of these methods features selection is even more critical, but it is known to be a NP-hard problem, and thus most feature selection approaches focuses on one feature at the time (k-best, Sequential Feature Selection, recursive feature elimination). We propose DNetPRO, Discriminant Analysis with Network PROcessing, a supervised network-based signature identification method. This method implements a network-based heuristic to generate one or more signatures out of the best performing feature pairs. The algorithm is easily scalable, allowing efficient computing for high number of observables ([Formula: see text]-[Formula: see text]). We show applications on real high-throughput genomic datasets in which our method outperforms existing results, or is compatible with them but with a smaller number of selected features. Moreover, the geometrical simplicity of the resulting class-separation surfaces allows a clearer interpretation of the obtained signatures in comparison to nonlinear classification models

    Observation of abundant heat production from a reactor device and of isotopic changes in the fuel

    Get PDF
    New results are presented from an extended experimental investigation of anomalous heat production in a special type of reactor tube operating at high temperatures. The reactor, named E-Cat, is charged with a small amount of hydrogen-loaded nickel powder plus some additives, mainly Lithium. The reaction is primarily initiated by heat from resistor coils around the reactor tube. Measurements of the radiated power from the reactor were performed with high-resolution thermal imaging cameras. The measurements of electrical power input were performed with a large bandwidth three-phase power analyzer. Data were collected during 32 days of running in March 2014. The reactor operating point was set to about 1260 ºC in the first half of the run, and at about 1400 °C in the second half. The measured energy balance between input and output heat yielded a COP factor of about 3.2 and 3.6 for the 1260 ºC and 1400 ºC runs, respectively . The total net energy obtained during the 32 days run was about 1.5 MWh. This amount of energy is far more than can be obtained from any known chemical sources in the small reactor volume. A sample of the fuel was carefully examined with respect to its isotopic composition before the run and after the run, using several standard methods: XPS, EDS, SIMS, ICP-MS and ICP-AES. The isotope composition in Lithium and Nickel was found to agree with the natural composition before the run, while after the run it was found to have changed substantially . Nuclear reactions are therefore indicated to be present in the run process, which however is hard to reconcile with the fact that no radioactivity was detected outside the reactor during the run

    Phosphoinositide 3-kinase γ-deficient hearts are protected from the PAF-dependent depression of cardiac contractility

    Get PDF
    Objectives: Following an ischemic insult, cardiac contractile recovery might be perturbed by the release of autacoids, like platelet-activating factor (PAF), that depress heart function by acting through G protein-coupled receptors (GPCRs). The signaling events downstream the PAF receptor that lead to the negative inotropic effect are still obscure. We thus investigated whether the GPCR-activated phosphoisositide 3-kinase γ (PI3Kγ) could play a role in the cardiac response to PAF. Methods: The negative inotropic effect of PAF was studied ex vivo, in isolated electrically driven atria and in Langendorff-perfused whole hearts derived from wild-type and PI3Kγ-null mice. Postischemic recovery of contractility was analyzed in normal and mutant whole hearts subjected to 30 min of ischemia and 40 min of reperfusion in the presence or absence of a PAF receptor antagonist. Results: While wild-type hearts stimulated with PAF showed increased nitric oxide (NO) production and a consequent decreased cardiac contractility, PI3Kγ-null hearts displayed reduced phosphorylation of nitric oxide synthase 3 (NOS3), blunted nitric oxide production and a complete protection from the PAF-induced negative inotropism. In addition, Langendorff-perfused PI3Kγ-null hearts showed a better contractile recovery after ischemia/reperfusion, a condition where PAF is known to be an important player in depressing contractility. In agreement with a role of PI3Kγ in this PAF-mediated signaling, postischemic contractile recovery in PI3Kγ-null mice appeared overlapping with that of normal hearts treated with the PAF receptor antagonist WEB 2170. Conclusion: These data indicate a novel PAF-dependent signaling pathway that, involving PI3Kγ and NOS3, contributes to postischemic contractile depressio
    corecore