21 research outputs found

    Using Light Charged Particles to Probe the Asymmetry Dependence of the Nuclear Caloric Curve

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    Recently, we observed a clear dependence of the nuclear caloric curve on neutron-proton asymmetry NZA\frac{N-Z}{A} through examination of fully reconstructed equilibrated quasi-projectile sources produced in heavy ion collisions at E/A = 35 MeV. In the present work, we extend our analysis using multiple light charged particle probes of the temperature. Temperatures are extracted with five distinct probes using a kinetic thermometer approach. Additionally, temperatures are extracted using two probes within a chemical thermometer approach (Albergo method). All seven measurements show a significant linear dependence of the source temperature on the source asymmetry. For the kinetic thermometer, the strength of the asymmetry dependence varies with the probe particle species in a way which is consistent with an average emission-time ordering.Comment: 7 pages, 4 figure

    Type-I interferon pathway and DNA damage accumulation in peripheral blood of patients with psoriatic arthritis

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    ObjectivesThe abnormal DNA damage response is associated with upregulation of the type-1 interferon (IFN-I) pathway in certain rheumatic diseases. We investigated whether such aberrant mechanisms operate in psoriatic arthritis (PsA).MethodsDNA damage levels were measured by alkaline comet assay in peripheral blood mononuclear cells from 52 PsA patients and age-sex-matched healthy individuals. RNA expression of IFIT1, MX1 and IFI44, which are selectively induced by IFN-I, was quantitated by real-time polymerase chain reaction and their composite normalized expression resulted in IFN-I score calculation. RNA expression of IL1β, IL6, TNF, IL17A and IL23A was also assessed in PsA and control subgroups.ResultsIn PsA, DNA damage accumulation was increased by almost two-fold compared to healthy individuals (olive tail moment arbitrary units, mean ± SD; 9.42 ± 2.71 vs 4.88 ± 1.98, p<0.0001). DNA damage levels significantly correlated with serum C-Reactive-protein and IL6 RNA expression in PBMCs. Despite increased DNA damage, the IFN-I score was strikingly lower in PsA patients compared to controls (-0.49 ± 6.99 vs 4.24 ± 4.26; p<0.0001). No correlation was found between IFN-I pathway downregulation and DNA damage. However, the IFN-I score in a PsA subgroup was lower in those patients with higher IL1β expression, as well as in those with higher TNF/IL23A PBMCs expression.ConclusionDNA damage in PsA correlates with measures of inflammation but is not associated with the IFN-I pathway induction. The unexpected IFN-I downregulation, albeit reminiscent to findings in experimental models of spondyloarthritis, may be implicated in PsA pathogenesis and explained by operation of other cytokines

    Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS

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    Abstract. The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay halflife. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported and the experimental challenges characterizing such activity are describe

    NURE: An ERC project to study nuclear reactions for neutrinoless double beta decay

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    Neutrinoless double beta decay (0νββ) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research “beyond Standard Model” and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0νββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extract information on the 0νββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0νββ

    Global prevalence and genotype distribution of hepatitis C virus infection in 2015 : A modelling study

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    Publisher Copyright: © 2017 Elsevier LtdBackground The 69th World Health Assembly approved the Global Health Sector Strategy to eliminate hepatitis C virus (HCV) infection by 2030, which can become a reality with the recent launch of direct acting antiviral therapies. Reliable disease burden estimates are required for national strategies. This analysis estimates the global prevalence of viraemic HCV at the end of 2015, an update of—and expansion on—the 2014 analysis, which reported 80 million (95% CI 64–103) viraemic infections in 2013. Methods We developed country-level disease burden models following a systematic review of HCV prevalence (number of studies, n=6754) and genotype (n=11 342) studies published after 2013. A Delphi process was used to gain country expert consensus and validate inputs. Published estimates alone were used for countries where expert panel meetings could not be scheduled. Global prevalence was estimated using regional averages for countries without data. Findings Models were built for 100 countries, 59 of which were approved by country experts, with the remaining 41 estimated using published data alone. The remaining countries had insufficient data to create a model. The global prevalence of viraemic HCV is estimated to be 1·0% (95% uncertainty interval 0·8–1·1) in 2015, corresponding to 71·1 million (62·5–79·4) viraemic infections. Genotypes 1 and 3 were the most common cause of infections (44% and 25%, respectively). Interpretation The global estimate of viraemic infections is lower than previous estimates, largely due to more recent (lower) prevalence estimates in Africa. Additionally, increased mortality due to liver-related causes and an ageing population may have contributed to a reduction in infections. Funding John C Martin Foundation.publishersversionPeer reviewe

    New results from the NUMEN project

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    NUMEN aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. First evidence about the possibility to get quantitative information about NME from experiments is found for the (18O,18Ne) and (20Ne,20O) reactions. Moreover, to infer the neutrino average masses from the possible measurement of the half-life of 0νββ decay, the knowledge of the NME is a crucial aspect. The key tools for this project are the high resolution Superconducting Cyclotron beams and the MAGNEX magnetic spectrometer at INFN Laboratori Nazionali del Sud in Catania (Italy). The measured cross sections are extremely low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to increase the experimental yield of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest. peerReviewe

    Studies of the Nuclear Landscape and the Nuclear Equation of State using Peripheral Collisions near the Fermi Energy

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    Studies of peripheral (quasi-elastic and deep-inelastic) collisions near the Fermi energy are presented with a two-fold goal: first, to produce very neutron-rich nuclei towards the neutron drip line and, second, to obtain insight into the underlying dynamics and the nuclear equation of state (EOS). Towards the first goal, our studies indicated an enhanced production of neutron-rich nuclides suggesting that peripheral reactions at Fermi energies offer a novel way to access very neutron-rich rare isotopes in unexplored regions of the nuclear chart. Towards the second goal, we have made comparisons of our experimental data to detailed calculations using the semiclassical microscopic model CoMD (Constrained Molecular Dynamics). The CoMD code implements an effective interaction with a nuclear-matter compressibility of K=200 (soft EOS) or K=380 (stiff EOS) with several forms of the density dependence of the nucleon-nucleon symmetry potential and imposes a phase space constraint to restore the Pauli principle during the collision. Present results from these comparisons are consistent with a soft equation of state (K=200) with a rather stiff density dependence of the symmetry potential (symmetry energy)

    Sustainable Urban Environment through Green Roofs: A Literature Review with Case Studies

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    This study conducts a literature review coupled with case-study calculations comparing the thermal contribution of semi-intensive and intensive (deeper) green roofs to non-insulated and insulated building roofs, and enhancing comprehension by validating applied scenarios with published literature-based data. Mitigation of the urban heat island is crucial for reducing energy consumption and enhancing urban sustainability, especially through natural solutions such as green (i.e., planted) roofs. The energy and environmental benefits of green roofs include energy conservation, thermal comfort, noise reduction, and aesthetic improvement. Legal mandates, innovative business models, financial subsidies and incentives, regulations, etc. are all components of green roof policies. Conflicts between private property owners and the public, regulatory gaps, and high installation costs are among the challenges. Green roofs are layered and incorporate interacting thermal processes. Green roof models are either based on the calculation of thermal transmittance (U-values), an experimental energy balance, or data-driven (primarily neural network) approaches. U-values were calculated for eight hypothetical scenarios consisting of four non-insulated and four insulated roofs, with or without semi-intensive and intensive green roofs of various materials and layer thicknesses. While the non-planted, non-insulated roof had the highest U-value, planted roofs were particularly effective for non-insulated roofs. Three of these scenarios were in reasonable accord with experimental and theoretical thermal transmittance literature values. Finally, a non-insulated planted roof, particularly one with rockwool, was found to provide a certain degree of thermal insulation in comparison to a non-planted insulated roof
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