Inflation and primordial black holes in matter domination

In this thesis we will study a new interpretation of dark matter in terms of Primordial Black Holes (PBHs), i.e. black holes that are believed to form when large density perturbations, produced during the inflationary epoch, reenter the horizon and collapse because of their own gravitational force. Black holes produced in this way are referred to as "Primordial" since their production mechanism has a primordial origin during inflation. These large density fluctuations are produced if the inflationary potential possesses enough tuning freedom to feature a slow-roll plateau followed by a near inflection point that greatly enhances the power spectrum of scalar perturbations. We examine PBH formation during a radiation dominated (RD) epoch and during a matter dominated (MD) epoch driven by a gravitationally coupled scalar field (modulus) which decays before Big Bang Nucleosynthesis in order to preserve its successful predictions. We will require in both cases that the produced PBHs constitute 100% of dark matter today. In the MD case, we find that the mass of the scalar field affects the enhancement required in the curvature power spectrum: for large modulus masses, this enhancement turns out to be smaller than the one in the RD case, meaning that in the case of horizon reentry during moduli domination the potential requires less tuning to produce the same amount of PBHs. Therefore, we focus on PBH production during a MD epoch. We then introduce a model of string inflation called "Fibre Inflation", that works particularly well for our purposes since it naturally leads to a post-inflationary epoch of MD driven by an axion-like modulus. In this model the inflationary potential has enough tuning freedom to induce a period of ultra slow-roll that enhances the density perturbations at the required PBH scales: we employ this potential to obtain a numerical estimate of the scalar power spectrum and the other inflationary observables

Isolation, structural elucidation and evaluation of bioactivity of secondary metabolites from aromatic plants

Salvia tingitana Etl. is an aromatic woody-based perennial shrub original from the Arabian region. The analysis of the surface extract of the aerial parts afforded one nor-sesterterpene, eight new sesterterpenes and five known sesterterpenes, together with other known compounds that include five labdane and one abietane diterpene, one sesquiterpene and four flavonoids. The methanolic extract of the roots of S. tingitana was also investigated. Salvia corrugata Vahl. is cultivated in the Mediterranean coastal area as an ornamental plant. The methanolic extract of the roots and the twelve semi-purified fractions obtained by its chromatographic separation were tested against several multidrug resistant clinical strains

Deep Echo State Networks for Diagnosis of Parkinson's Disease

In this paper, we introduce a novel approach for diagnosis of Parkinson's Disease (PD) based on deep Echo State Networks (ESNs). The identification of PD is performed by analyzing the whole time-series collected from a tablet device during the sketching of spiral tests, without the need for feature extraction and data preprocessing. We evaluated the proposed approach on a public dataset of spiral tests. The results of experimental analysis show that DeepESNs perform significantly better than shallow ESN model. Overall, the proposed approach obtains state-of-the-art results in the identification of PD on this kind of temporal data.Comment: This is a pre-print of the paper submitted to the European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning, ESANN 201

Understanding the molecular mechanisms behind lipid homeostasis: the role of apoE and hepatic ACAT 2 in atherogenesis

The general aim of this work was to investigate the molecular mechanisms involved in lipoprotein metabolism and lipid homeostasis trying to further clarify the role played by apolipoprotein E and hepatic Acyl-conzyme A:cholesterol acyltransferase 2 (ACAT2). ApoE-/- mice provide the the most useful model to study hyperlipidemia and atherosclerosis. In the first part of this work we assessed whether the expression of apoE may have a significant impact on the atheroprotective process of reverse cholesterol transport (RCT) in mice. In the second part of this work we focused attention on ACAT2 down-regulation by antisense oligonucleotide therapy (ASO), a new potential strategy to retard atherosclerosis. We investigated whether a decreased hepatic ACAT2 activity may increase HDL synthesis and affect triglyceride and cholesterol metabolism by activation of the LXR pathway. From RCT study we concluded that apoE is essential for functional RCT. The use of anti-sense oligonucleotide targeted to hepatic ACAT2 revealed a new pathway by which the liver contributes to HDL metabolism and identify ACAT2 as an important intracellular player in the determination of cholesterol fluxes either into apoB-containing lipoprotein secretion or into apoA-I

American direct investments in Argentina, Brazil, Chile.

Thesis (M.B.A.)--Boston University N.B.: Page 184 missing from originals

I Wormholes ed il loro impiego per il viaggio interstellare

Viaggiare da un punto all'altro dell'universo muovendosi in uno spazio-tempo piatto richiede tempi talmente colossali da risultare impossibile per la nostra razza; pertanto, un viaggio interstellare potrebbe essere realizzato solo per mezzo di topologie relativistiche in grado di accorciare la distanza fra i punti dell'universo. Dopo aver dato una serie di motivazioni per cui i buchi neri ed il ponte di Einstein-Rosen non sono adatti ad essere impiegati viene introdotta una particolare classe di soluzioni, presentata per la prima volta da Michael S. Morris e Kip S. Thorne, delle equazioni di Einstein: essa descrive wormholes i quali, almeno in linea di principio, risultano attraversabili dagli esseri umani in quanto non presentano un orizzonte degli eventi sulla gola. Quest'ultima proprietà, insieme alle equazioni di campo di Einstein, pone dei vincoli piuttosto estremi sul tipo di materiale in grado di dar luogo alla curvatura spazio-temporale del wormhole: nella gola del wormhole la materia deve possedere una tensione radiale di enorme intensità, dell'ordine di quella presente nel centro delle stelle di neutroni più massive per gole con un raggio di appena qualche kilometro. Inoltre, questa tensione dev'essere maggiore della densità di energia del materiale: ad oggi non si conosce alcun materiale con quest'ultima proprietà, la quale viola entrambe le "condizioni sull'energia" alla base di teoremi molto importanti e verificati della relatività generale. L'esistenza di questa materia non può essere esclusa a priori, visto che non esiste prova sperimentale o matematica della sua irrealisticità fisica, ma non essendo mai stata osservata è importante assicurarsi di impiegarne il meno possibile nel wormhole: questo ci porterà a mostrare che i wormholes in cui il materiale esotico presenta una densità di energia negativa per gli osservatori statici sono i più adatti al viaggio interstellare

Occurrence of fig mosaic disease in Tuscany, Central Italy: Characterization of new fig mosaic virus isolates, and elucidation of physiochemical responses of infected common fig cv. Dottato

Fig mosaic disease (FMD) is a major disease affecting fig trees, for which only fig mosaic virus (FMV) has been identified as etiological agent. In the present study, trees of common fig cv. Dottato, belonging to the old Tuscan germplasm, were investigated to pioneering (i) evaluate the presence of FMV in Tuscany (Central Italy), as well as other FMD-associated viruses previously reported in Italy, (ii) type and phylogenetically characterize the reported FMV isolates, and (iii) elucidate some physiological and biochemical responses of fig trees challenged by FMV. Although many studies on FMD have been carried out in Southern Italy, the present study represents the first identification of the disease in another Italian area. This work (i) showed that FMD is present also in Central Italy, also suggesting a wider diffusion than what has been reported so far; (ii) confirmed that the disease is caused by FMV, tested positive in both symptomatic and asymptomatic leaves (100 and 27% of tested samples, respectively); and also fig fleck-associated virus (FFKaV) was reported; (iii) identified three new FMV isolates (i. e., Dot-1, Dot-2 and Dot-3, deposited in GenBank), which resulted not close to other FMV Italian isolates; and (iv) pioneering elucidated that FMV impaired photosynthesis and organic acid biosynthesis in symptomatic leaves, but negative effects occurred also in asymptomatic ones in terms of photosynthetic and accessory pigments. More research should be carried out to improve our knowledge on FMD diffusion and FMV (and FFKaV) genetic features, as well on the effects of this regulated non quarantine pest on fig trees, also investigating its fruits representing an ancient source of food and health