Extremals for fractional Moser-Trudinger inequalities in dimension 1 via harmonic extensions and commutator estimates

We prove the existence of extremals for fractional Moser-Trudinger inequalities in an interval and on the whole real line. In both cases we use blow-up analysis for the corresponding Euler-Lagrange equation, which requires new sharp estimates obtained via commutator techniques

Remarks on the Moser-Trudinger inequality

We extend the Moser-Trudinger inequality to any Euclidean domain satisfying Poincar\'e's inequality. We find out that the same equivalence does not hold in general for conformal metrics on the unit ball, showing counterexamples. We also study the existence of extremals for the Moser-Trudinger inequalities for unbounded domains, proving it for the infinite planar strip.Comment: 32 pages, accepted on Advances in Nonlinear Analysi

DESIGN, SYNTHESIS AND CHARACTERIZATION OF POLYAMINE- AND SQUARAMIDE-BASED FLUORESCENT CHEMOSENSORS FOR SELECTIVE RECOGNITION OF ORGANIC MOLECULES AND METAL CATIONS IN SOLUTION

The present thesis describes two class of optical receptor able to be used as chemosensors for anionic species: the first class is constituted by seven squaramide-based system (L1-L7), the second one lies to two tetraazaprifane systems (L8-L9). Bis-squaramide ligands L1-L4 bearing a dansyl moiety were synthesised and their potential applications as fluorescent probes were investigated towards non-steroidal anti-inflammatory drugs Naproxen and Ketoprofen. Each ligand contains two squaramide units connected via a dipropylenamine spacer bearing a dansyl group as fluorescent signaling unit linked to the central nitrogen atom. The four ligands show different structural features: L1 and L2 have a macrocyclic topology while L3 and L4 are open-chain ligands. The non-fluorescent ligand L5 showing the same macrocyclic topology of L1 has been also studied for comparison. The aim of the study is to understand how and at which extent the molecular topology and the number of HB donors of the receptors influence the selectivity and the signaling efficiency towards the selected targets analytes NPX and KET in their anionic forms. Ligands L6 and L7 showed excellent ability to selectively bind NSAIDs through converging hydrogen bonds with a clear spectrophotometric output. They represent the single-arm and the double-arm version of the same ligand. They are both open-chain sensors in which the coordinating unit is represented by a squaramide covalently bonded to a 7-amino-4-(trifluoromethyl)coumarin. In the case of L6 the spacer that connects the two equivalent branches is a m-xylylenediamine, therefore a benzylamine was used for the synthesis of L7. The rationale in the design of these two ligands lies in looking for an eventual selectivity between the anions of four specific NSAIDs – Ibuprofen, Ketoprofen, Diclofenac and Naproxen – and a possible synergistic effect of the two branches in the case of the double sensor with respect to its single analogue. The receptor L8 consists of two “scorpiand” polyamine subunits connected by a luminescent biphenol spacer. The receptor has been salified with HCl making it perfectly soluble in an aqueous environment as well as characterizing by potentiometric means. The coordination and the fluorescence behavior of the binuclear species [Zn2L] in an aqueous environment both in the total pH range and in a buffered environment was studied. The focus of the project was to try to understand and explain the unusual fluorescence behavior of L8 in the presence of Zn2+ using different characterization techniques. Preliminary studies have also been carried out in the presence of organic molecules such as L-aspartic acid, L-glutamic acid, succinic acid and glutaric acid. The scorpiand-type polyamine chemosensor L9, bearing a fluorescent acridine moiety as signalling unit, has been designed and synthesized to selectively recognize nucleotides in aqueous media. L9 has a 12-membered polyamine macrocycle and the sensing material is connected to the acridinine-based fluorescent signal transducer via an N1-ethylpropane-1,3-diamine chain. The chosen nucleotides were those of the “triphosphate” series: ATP, GTP and UTP to which was also added the “monophosphate” GMP.The present thesis describes two class of optical receptor able to be used as chemosensors for anionic species: the first class is constituted by seven squaramide-based system (L1-L7), the second one lies to two tetraazaprifane systems (L8-L9). Bis-squaramide ligands L1-L4 bearing a dansyl moiety were synthesised and their potential applications as fluorescent probes were investigated towards non-steroidal anti-inflammatory drugs Naproxen and Ketoprofen. Each ligand contains two squaramide units connected via a dipropylenamine spacer bearing a dansyl group as fluorescent signaling unit linked to the central nitrogen atom. The four ligands show different structural features: L1 and L2 have a macrocyclic topology while L3 and L4 are open-chain ligands. The non-fluorescent ligand L5 showing the same macrocyclic topology of L1 has been also studied for comparison. The aim of the study is to understand how and at which extent the molecular topology and the number of HB donors of the receptors influence the selectivity and the signaling efficiency towards the selected targets analytes NPX and KET in their anionic forms. Ligands L6 and L7 showed excellent ability to selectively bind NSAIDs through converging hydrogen bonds with a clear spectrophotometric output. They represent the single-arm and the double-arm version of the same ligand. They are both open-chain sensors in which the coordinating unit is represented by a squaramide covalently bonded to a 7-amino-4-(trifluoromethyl)coumarin. In the case of L6 the spacer that connects the two equivalent branches is a m-xylylenediamine, therefore a benzylamine was used for the synthesis of L7. The rationale in the design of these two ligands lies in looking for an eventual selectivity between the anions of four specific NSAIDs – Ibuprofen, Ketoprofen, Diclofenac and Naproxen – and a possible synergistic effect of the two branches in the case of the double sensor with respect to its single analogue. The receptor L8 consists of two “scorpiand” polyamine subunits connected by a luminescent biphenol spacer. The receptor has been salified with HCl making it perfectly soluble in an aqueous environment as well as characterizing by potentiometric means. The coordination and the fluorescence behavior of the binuclear species [Zn2L] in an aqueous environment both in the total pH range and in a buffered environment was studied. The focus of the project was to try to understand and explain the unusual fluorescence behavior of L8 in the presence of Zn2+ using different characterization techniques. Preliminary studies have also been carried out in the presence of organic molecules such as L-aspartic acid, L-glutamic acid, succinic acid and glutaric acid. The scorpiand-type polyamine chemosensor L9, bearing a fluorescent acridine moiety as signalling unit, has been designed and synthesized to selectively recognize nucleotides in aqueous media. L9 has a 12-membered polyamine macrocycle and the sensing material is connected to the acridinine-based fluorescent signal transducer via an N1-ethylpropane-1,3-diamine chain. The chosen nucleotides were those of the “triphosphate” series: ATP, GTP and UTP to which was also added the “monophosphate” GMP

Higher education in the UK and the market for labour : evidence from the Universities' Statistical Record

The Thesis seeks to make a contribution to our current understanding of the complex relationship between higher education and the graduate labour market in the UK on both a methodological and policy level. Using administrative data from the Universities' Statistical Record (USR) on complete cohorts of individual students who left university between 1980 and 1993, the Thesis develops along three main avenues: i) identifying the key determinants of graduates' first destinations (Chapters 2 and 3); ii) comparing alternative indicators of employment-related university performance and assessing their robustness to data aggregation (Chapter 4); iii) estimating the differences in graduates' occupational earnings by degree subject (Chapter 5). The study on first destination considers a broad range of possible outcomes distinguishing between temporary and permanent as well as 'graduate' and 'nongraduate' employment, professional training and postgraduate study, involuntary unemployment and unavailability for work. The analysis reveals significant effects on graduates' employability associated with gender, university type, degree subject, degree class, socio-economic background, and prior qualifications (Chapter 2). Moreover, the impact of all the main factors affecting graduates' early careers has a significant correlation with the business cycle (Chapter 3). In Chapter 4 we compare employment-related university performance indicators constructed from student-level and university-level data, respectively. Despite student-level data on university statistics now being publicly available, institutions are currently assessed according to indicators based on university-level data, implicitly obtained by averaging over individuals the corresponding student-level information. We find significant differences between the two sets of indicators and argue that the observed discrepancies are the result of an aggregation bias. A Monte Carlo experiment is used to test the validity of this conclusion. Finally, Chapter 5 looks at the differences of graduates' occupational earnings by degree subject using USR and NES data from 1980 to 1993. We discuss the issue of self-selection of students into the subject of study and apply three alternative modelling strategies to control for self-selection: the proxy and matching method, propensity score matching and a simultaneous equations model accounting for 'selection on unobservables'. The evidence suggests the presence of a significant selection bias originating from the unaccounted correlation between unobservable individual characteristics affecting both occupational earnings and subject choice. Moreover, the ranking of university subjects changes over time

Increased expression and activity of p75NTR are crucial events in azacitidine-induced cell death in prostate cancer

The high affinity nerve growth factor (NGF) NGF receptor, p75NTR, is a member of the tumor necrosis factor (TNF) receptor superfamily that shares a conserved intracellular death domain capable of inducing apoptosis and suppressing growth in prostate epithelial cells. Expression of this receptor is lost as prostate cancer progresses and is minimal in established prostate cancer cell lines. We aimed to verify the role of p75NTR in the azacitidine-mediated antitumor effects on 22Rv1 and PC3 androgen-independent prostate cancer cells. In the present study, we reported that the antiproliferative and pro-apoptotic effects of 5-azacytidine (azacitidine) were more marked in the presence of physiological concentrations of NGF and were reduced when a blocking p75NTR antibody or the selective p75NTR inhibitor, Ro 08-2750, were used. Azacitidine increased the expression of p75NTR without interfering with the expression of the low affinity NGF receptor TrkA and induced caspase 9-dependent caspase 3 activity. Taken together, our results suggest that the NGF network could be a candidate for future pharmacological manipulation in aggressive prostate cancer

Project controlling in mega events: the Expo 2015 case

Although Universal Expositions are an incredible catalyst for the development of hosting cities, they have to face projects’ common problems as over-budgets and delays. This last issue is critic since mega events have to respect a mandatory deadline and any delay could cause critical project scope reduction. It is thus fundamental to control efficiently and effectively their progress to obtain the best performances. Despite “project controlling” field is well-documented concerning mega-projects, there is a gap for mega events. In addition, literature focuses on strategic elements without providing operative methods to control the execution phase. This paper fi lls this gap highlighting how mega-events can be considered as “mega-programmes”, suggesting supervision through a project envelope to avoid forecasting problems and proposing a gradual control according to project statuses. These results provide a model to monitor Milan Expo 2015 execution phase, guaranteeing that all projects involved end within deadlines

Performance Modeling in Predictable Cloud Computing

This paper deals with the problem of performance stability of software running in shared virtualized infrastructures. The focus is on the ability to build an abstract performance model of containerized application components, where real-time scheduling at the CPU level, along with traffic shaping at the networking level, are used to limit the temporal interferences among co-located workloads, so as to obtain a predictable distributed computing platform. A model for a simple client-server application running in containers is used as a case-study, where an extensive experimental validation of the model is conducted over a testbed running a modified OpenStack on top of a custom real-time CPU scheduler in the Linux kernel

Attitudes towards Interprofessional Education among Medical and Nursing Students: the Role of Professional Identification and Intergroup Contact

This research analyses the effect of professional identification and intergroup contact on attitudes towards interprofessional education (IPE) among medical and nursing students. Three hundred fifty-eight nursing and medical students were surveyed measuring attitudes towards IPE and professional identification. Moreover, students were asked to report the hours of practical training that they had already done, as measure of intergroup contact. Results indicated that ingroup identification increased attitude towards IPE among nursing students, while it decreased attitude among medical students. Intergroup contact, instead, had not significant effect. Results are discussed on the basis of social identity theory and status differences between professional groups

Interpreting the evolution of galaxy colours from z=8z = 8 to z=5z = 5

We attempt to interpret existing data on the evolution of the UV luminosity function and UV colours, $\beta$, of galaxies at $5 \leq z \leq 8$, to improve our understanding of their dust content and ISM properties. To this aim, we post-process the results of a cosmological hydrodynamical simulation with a chemical evolution model, which includes dust formation by supernovae and intermediate mass stars, dust destruction in supernova shocks, and grain growth by accretion of gas-phase elements in dense gas. We find that observations require a steep, Small Magellanic Cloud-like extinction curve and a clumpy dust distribution, where stellar populations younger than 15 Myr are still embedded in their dusty natal clouds. Investigating the scatter in the colour distribution and stellar mass, we find that the observed trends can be explained by the presence of two populations: younger, less massive galaxies where dust enrichment is mainly due to stellar sources, and massive, more chemically evolved ones, where efficient grain growth provides the dominant contribution to the total dust mass. Computing the IR-excess - UV color relation we find that all but the dustiest model galaxies follow a relation shallower than the Meurer et al. (1999) one, usually adopted to correct the observed UV luminosities of high-$z$ galaxies for the effects of dust extinction. As a result, their total star formation rates might have been over-estimated. Our study illustrates the importance to incorporate a proper treatment of dust in simulations of high-$z$ galaxies, and that massive, dusty, UV-faint galaxies might have already appeared at $z \lesssim 7$.Comment: accepted in MNRA