On the mass of supernova progenitors: the role of the 12^{12}C+12+^{12}C reaction

A precise knowledge of the masses of supernova progenitors is essential to answer various questions of modern astrophysics, such as those related to the dynamical and chemical evolution of Galaxies. In this paper we revise the upper bound for the mass of the progenitors of CO white dwarfs (\mup) and the lower bound for the mass of the progenitors of normal type II supernovae (\mups). In particular, we present new stellar models with mass between 7 and 10 \msun, discussing their final destiny and the impact of recent improvements in our understanding of the low energy rate of the \c12c12 reaction.Comment: To be published on the proceedings of NIC 201

Evolution, nucleosynthesis and yields of AGB stars at different metallicities (III): intermediate mass models, revised low mass models and the ph-FRUITY interface

We present a new set of models for intermediate mass AGB stars (4.0, 5.0 and, 6.0 Msun) at different metallicities (-2.15<=Fe/H]<=+0.15). This integrates the existing set of models for low mass AGB stars (1.3<=M/M<=3.0) already included in the FRUITY database. We describe the physical and chemical evolution of the computed models from the Main Sequence up to the end of the AGB phase. Due to less efficient third dredge up episodes, models with large core masses show modest surface enhancements. The latter is due to the fact that the interpulse phases are short and, then, Thermal Pulses are weak. Moreover, the high temperature at the base of the convective envelope prevents it to deeply penetrate the radiative underlying layers. Depending on the initial stellar mass, the heavy elements nucleosynthesis is dominated by different neutron sources. In particular, the s-process distributions of the more massive models are dominated by the \nean~reaction, which is efficiently activated during Thermal Pulses. At low metallicities, our models undergo hot bottom burning and hot third dredge up. We compare our theoretical final core masses to available white dwarf observations. Moreover, we quantify the weight that intermediate mass models have on the carbon stars luminosity function. Finally, we present the upgrade of the FRUITY web interface, now also including the physical quantities of the TP-AGB phase of all the models included in the database (ph-FRUITY).Comment: Accepted for publication on ApJ

UNRAVELING THE MOLECULAR COMPLEXITY OF PARKINSON&#191;S DISEASE: FROM GENETIC RISK FACTORS TO MENDELIAN CAUSATIVE GENES

Parkinson\u2019s disease (PD) is a neurodegenerative disorder characterized by the progressive death of dopaminergic neurons in the substantia nigra. PD is a complex disease caused by the combination of environmental factors and genetic components. In recent years, considerable progresses have been made in the identification of the genetic determinants of PD: several genes were shown to cause rare monogenic forms of the disease. Moreover, a larger number of predisposing genetic variants have been associated with sporadic PD by genome-wide association studies. Among them, GBA seems to be the main genetic risk factor for PD. However, despite these advancements, a large fraction of the expected PD heritability is still missing. In this frame, the main aims of my PhD project were, on one hand, the study of the possible mechanisms of regulation of GBA, in particular the assessment of the role of GBAP1, its pseudogene, with the view to identify novel strategies to augment glucocerebrosidase activity and, on the other hand, the identification of novel genetic determinants for the disease by whole-exome sequencing (WES) of selected PD families. Concerning GBA we demonstrated that mir-22-3p can modulate the levels of GBA transcripts down-regulating GCase expression and that GBAP1 might work as competing endogenous RNA acting as sponge and decreasing the miRNA mediated control on GBA. We then characterized the splicing pattern of the pseudogene and we showed that GBAP1 transcripts are down-regulated by the nonsense-mediated mRNA decay mechanism. On the basis of these results, we propose the existence of an RNA-based complex regulatory network involving GBA, GBAP1 and miR-22-3p. Regarding the identification of novel PD genes, 24 PD families with a dominant or a recessive inheritance pattern were selected and whole-exome sequencing was performed on the proband of each family and on affected cousins or uncles, when available. Six of these families resulted carriers of mutations in genes already associated with parkinsonism (4 GBA, 1 LRRK2, and 1 ATP7B). Moreover, we found 2 homozygous mutations in novel candidate genes in 2 consanguineous families: a splicing mutation in a gene involved in the unfolded protein response (DNAJC12) and a missense variant in a gene coding for a lysosomal enzyme (HGSNAT). We characterized the splicing mutation and we demonstrated that this variation causes the skipping of the downstream exon and the introduction of the premature stop codon. Interestingly, we demonstrated that the silencing of the DNAJC12 gene increases the \u3b1-synuclein protein levels in SH-SY5Y neuroblastoma cells. Concerning the missense mutation, we measured the activity of the HGSNAT enzyme in the patient\u2019s fibroblasts, which resulted below the lower limit of the normal range. We hypothesize that the HGSNAT activity is not reduced enough to cause a lysosomal disorder, but may predispose to PD. Moreover, the pathogenic role of the two novel PD genes identified in my PhD project is strongly supported by the identification, by us and by our collaborators in Vancouver, of one additional unrelated PD family with mutations in the same gene for both HGSNAT and DNAJC12. Ongoing analyses will characterize the functional role of the novel candidate genes in PD pathogenesis

Discovery of an anomalous Sub Giant Branch in the Color Magnitude Diagram of omega Centauri

Using deep high-resolution multi-band images taken with the Very Large Telescope and the Hubble Space Telescope, we discovered a new anomalous sequence in the Color Magnitude Diagram of omega Cen. This feature appears as a narrow, well-defined Sub Giant Branch (SGB-a), which merges into the Main Sequence of the dominant cluster population at a magnitude significantly fainter than the cluster Turn-Off (TO). The simplest hypothesis assumes that the new feature is the extension of the anomalous Red Giant Branch (RGB-a) metal-rich population discovered by Lee et al. (1999) and Pancino et al. (2000). However, under this assumption the interpretation of the SGB-a does not easily fit into the context of a self-enrichment scenario within omega Cen. In fact, its TO magnitude, shape and extension are not compatible with a young, metal-rich population, as required by the self-enrichment process. The TO level of the SGB-a suggests indeed an age as old as the main cluster population, further supporting the extra-cluster origin of the most metal rich stars, as suggested by Ferraro, Bellazzini & Pancino (2002). Only accurate measurements of radial velocities and metal abundances for a representative sample of stars will firmly establish whether or not the SGB-a is actually related to the RGB-a and will finally shed light on the origin of the metal rich population of omega Cen.Comment: ApJL, in pres

Une collection de musique populaire suisse

Canti liturgici popolari nel Ticino. Liturgia eucaristica e dell’ufficiatura funebre (enregistrements Arnold Geering, 1949-1952) ; Vespro 1983, enregistrements Pietro Bianchi, Texte de présentation : P. Bianchi. Un microsillon Fata Morgana FM 84022, 1984. Der Volksliedsänger und -forscher Hanns in der Gand. Enregistrements 1925-1934. Texte de présentation : Christine Burckhardt-Seebass. Un microsillon Fata Morgana FM 84023, 1984. Musique populaire suisse. Collection Constantin Brăiloiu. Chans..

Targeting bacterial cell division: A binding site-centered approach to the most promising inhibitors of the essential protein FtsZ

Binary fission is the most common mode of bacterial cell division and is mediated by a multiprotein complex denominated the divisome. The constriction of the Z-ring splits the mother bacterial cell into two daughter cells of the same size. The Z-ring is formed by the polymerization of FtsZ, a bacterial protein homologue of eukaryotic tubulin, and it represents the first step of bacterial cytokinesis. The high grade of conservation of FtsZ in most prokaryotic organisms and its relevance in orchestrating the whole division system make this protein a fascinating target in antibiotic research. Indeed, FtsZ inhibition results in the complete blockage of the division system and, consequently, in a bacteriostatic or a bactericidal effect. Since many papers and reviews already discussed the physiology of FtsZ and its auxiliary proteins, as well as the molecular mechanisms in which they are involved, here, we focus on the discussion of the most compelling FtsZ inhibitors, classified by their main protein binding sites and following a medicinal chemistry approach

Une collection de musique populaire suisse

Canti liturgici popolari nel Ticino. Liturgia eucaristica e dell’ufficiatura funebre (enregistrements Arnold Geering, 1949-1952) ; Vespro 1983, enregistrements Pietro Bianchi, Texte de présentation : P. Bianchi. Un microsillon Fata Morgana FM 84022, 1984. Der Volksliedsänger und -forscher Hanns in der Gand. Enregistrements 1925-1934. Texte de présentation : Christine Burckhardt-Seebass. Un microsillon Fata Morgana FM 84023, 1984. Musique populaire suisse. Collection Constantin Brăiloiu. Chans..