289 research outputs found
The Effects of Social Security on the Distribution of Wealth in Italy
The degree of substitutability between social security wealth and private wealth is a much-debated topic; however, less time and energy has been devoted to the study of the distributive properties of a measure of wealth summing future pension benefits net of contributions to the other traditional components of householdsâ net worth (financial and real activities, net of liabilities). The present paper has two essential aims: by using six cross-sections of the Bank of Italyâs Survey of Income and Wealth (1991, 1993, 1995, 1998, 2000 and 2002), it firstly aims to estimate an âaugmentedâ measure of net worth incorporating social security wealth, and secondly it examines the composition and distribution of such augmented wealth among Italian households during the period 1991-2002. The result is that augmented wealth is found to have remained constant in real term over the last decade due to two opposing forces, namely an increase in net worth and a parallel, stronger decline in social security wealth, resulting from the two main pension reforms implemented in 1992 and 1995. Wealth inequality, after rising steeply at the beginning of the 1990s, levelled off during the second part of the period in question. The major contribution towards this upwards movement came from social security wealth, the distribution of which, although less unequal than that of real wealth and financial wealth, widened at a much faster pace at the beginning of the decade.
The effects of social security on the distribution of wealth in Italy
The degree of substitutability between social security wealth and private wealth is a widely discussed topic. Much less effort is devoted to study the distributive properties of a measure of wealth which sums the future streams of pension benefits net of the contributions to the other traditional components of households net worth (financial and real activities, net of liabilities). This paper has two aims. By using the last six crosssections of the Bank of Italy Survey of Income and Wealth, firstly it estimates an âaugmentedâ measure of net worth which incorporates social security wealth, and secondly it examines the composition and the distribution of such augmented wealth among Italian households in the period 1991-2002. Augmented wealth is found to have fallen in the last decade as a product of two opposite forces, an increase in net worth and a parallel stronger decline in social security wealth, due to the two main pension reforms in 1992 and 1995. Wealth inequality, after rising steeply at the beginning of the 1990s, levelled off in the second part of the period. The major contribution to the upwards movement mainly came from social security wealth, whose distribution, although less unequal than the real and financial one, widened in the first part of the decade at a much faster pace.Social security wealth; Wealth distrubution; Wealth inequality; Italy
New Criteria of Targeting Welfare in Italy: an Appraisal of the Distributive Effects
Means-tested social assistance programs have acquired, in the last two decades, an increasing role in the majority of industrialised countries. Although the issue of whether social assistance should be targeted or universally granted remains a main subject of dispute (Harding et al. 1994; Mitchell 1995; Smolensky et al. 1995; Atkinson 1995, 1998), the shift towards targeting is in practice quite widespread, mainly reflecting the wish to curb social security budgets in a general context of fiscal restraint. The issue of targeting welfare assumes a particular importance in Italy, whose social assistance programs resemble more the rudimentary regimes typical of Southern Europe than the evolved systems of other EU countries. Indeed, the Italian welfare system is characterised by a number of categorical schemes limited to aged and disabled people, a discretionary relief (mainly in kind) provided by regional and local governments, and the absence of a national minimum income scheme as a universal safety net. To tackle these severe shortcomings, an articulated plan of reform proposals has been put forward in a report issued in 1997 by a special governmental commission on social expenditure. Some of its proposals have recently found two important applications, the reform of means-testing criteria and the experimental introduction of a national safety net scheme, an absolute novelty for the Italian system. The strategy behind the reform is to increase assistance for those most in need and to ensure that public expenditure is better targeted. The paper deals with the distributive implications associated with this reform plan, and in particular with the new entitlement rules which have recently designed to establish the access to welfare expenditure. Section 2 critically reviews the Italian social assistance system and briefly describes the institutional design of the new targeting system, which will gradually substitute the tests of means currently applied. Using the micro-data contained in the most recent sample survey of household income and wealth conducted by the Bank of Italy 1 and the tax-benefit microsimulation model Dirimod95, Section 2 also examines the sense in which the shortcomings mentioned above substantially undermine the effectiveness and efficiency of income support programs in alleviating poverty among Italian households. Section 3 is devoted to study how different economic and demographic groups of the population are likely to change their relative position if households are ranked first by a variable representing old means-testing criteria, and then by the new test of means; this analysis aims to clarify how various groups are likely to change their relative probabilities to access social services. Section 4 evaluates the distributive impact of the new spending programs introduced with the budget law for 1999 and of some reforms of the whole assistance system which, although highly speculative, can shed some light on the likely direction towards which the Italian welfare state is evolving. Finally, Section 5 concludes
Modelli di Microsimulazione dinamici e analisi di lungo periodo delle politiche fiscali
Questo lavora effettua una ricognizione nel campo della microsimulazione dinamica per l'analisi delle politiche fiscali al fine di mostrarne le caratteristiche generali, i pregi e i limiti attualmente riscontrabili. Alla luce delle esperienze maturate, in particolare, negli Stati Uniti, in Germania e nel Regno Unito, si evidenziano i principali problemi metodologi e di qualitĂ dei dati che la costruzione di modelli di microsimulazione dinamici pone rispetto a quelli statici. Un sottoinsieme di modelli dinamici, quelli a coorte dinamica, Ăš preso in esame piĂč in dettaglio. Di questi si descrive la struttura, le difficoltĂ concettuali e i margini di applicazione per l'analisi redistributiva di tipo life-cycle
One, Two, Many Nanocrystals: Characterizing Lead Halide Nanostructures from Single Particle to Bulk
Negli ultimi decenni la chimica colloidale ha prodotto una crescente varietĂ di nanostrutture inorganiche con proprietĂ variegate e finemente regolabili, che possono essere ottimizzate per diverse applicazioni. Tuttavia, questa varietĂ complica la caratterizzazione strutturale dei nanomateriali, le cui piccole dimensioni e lâintrinseca complessitĂ impongono limitazioni tecniche.
Questa Tesi ha come obiettivo quello di affrontare tali sfide proponendo nuovi approcci per caratterizzare e descrivere la struttura dei nanomateriali, approcci che sono qui applicati su nanostrutture di semiconduttori piombo-alogeno. Questi materiali sono molto studiati per le loro interessanti proprietĂ e per la diversitĂ strutturale che esprimono alla nanoscala, e per questo offrono molti interrogativi scientifici. Sono qui discussi quattro casi studio, ciascuno caratterizzato da una crescente complessitĂ .
I) La scoperta di nuovi calcoalogenuri di piombo sotto forma di nanocristalli Ăš sfruttata per sperimentare strategie di soluzione strutturale per nanomateriali inorganici basate sullâutilizzo combinato di tecniche di diffrazione a raggi X ed elettroniche. Sono proposte linee guida per ogni fase del processo di soluzione strutturale, dalla determinazione della stechiometria, allâindicizzazione della cella, fino al raffinamento della struttura.
II) Viene discusso come le trasformazioni chimiche tra nanocristalli di alogenuri di piombo-cesio prevedano la formazione di dimeri epitassiali come intermedi di reazione, la cui formazione dipende da specifiche relazioni strutturali. Sulla base di questa scoperta, si dimostra che la formazione di eterostrutture epitassiali tra perovskiti e calcoalogenuri puĂČ essere sfruttata efficacemente per indirizzare la sintesi fase-selettiva di nanocristalli colloidali.
III) Viene proposto un nuovo metodo per caratterizzare la struttura di solidi formati da nanocristalli auto-assemblati, qui dimostrato su superreticoli di nanocristalli di perovskiti piombo-alogeno. Tale metodo si basa su tecniche di diffrazione sviluppate per film sottili multistrato cresciuti tramite metodi fisici, e sfrutta l'analisi di fenomeni di interferenza collettiva nella regione ad alti angoli del diffrattogramma a raggi X del campione.
IV) Campioni microcristallini di perovskiti Ruddlesden-Popper, che sono alogenuri ibridi composti da strati organici e inorganici nanoscopici ordinatamente impilati, sono studiati tramite un'analisi geometrica dei loro parametri di cella per determinare come alogenuri diversi si dispongano disomogeneamente all'interno della struttura cristallina del materiale.Over the past few decades colloidal chemistry has provided access to a growing variety of inorganic nanostructures with diverse and customizable properties, which can be tailored to many different applications. However, such diversity presents challenges when it comes to characterizing the structure of functional nanomaterials, where the small size and the increased complexity impose technical limitations.
This Thesis aims to address these challenges by developing novel approaches to characterize and describe the structure of nanomaterials, which are here demonstrated on lead halide semiconductor nanostructures. These materials are widely investigated for their appealing properties and the structural diversity they express at the nanoscale, and pose therefore a variety of compelling scientific questions. Here are discussed four case studies, each characterized by increasing nanoscale complexity.
I) Colloidal nanocrystals of previously unknown lead chalcohalide phases are used to demonstrate strategies for solving the structure of novel inorganic materials by means of combined electron and X-ray diffraction techniques. Guidelines are proposed for each step of the structure solution process, from the stoichiometry determination to the cell indexation and the final structure refinement.
II) Epitaxial dimers formed by cesium lead halide compounds are rationalized as reaction intermediates in the chemical transformation of colloidal nanocrystals, and the structural relationships enabling their formation are explored. Following this lead, perovskite/chalcohalide heterostructures are demonstrated as effective templates for the phase-selective synthesis of colloidal nanocrystals.
III) Superlattices of lead halide perovskite nanocrystals are used to develop a novel approach for characterizing the nanoscale structure of self-assembled nanocrystal solids. This method is based on diffraction techniques developed for multilayer thin films grown by physical methods, and relies on the analysis of collective interference phenomena in the wide-angle X-ray diffraction pattern of samples.
IV) Microcrystalline samples of hybrid layered Ruddlesden-Popper perovskites, composed by nanoscale stacks of organic and inorganic layers, are investigated through a geometric analysis of their unit cell parameters to determine the inhomogeneous distribution of different halides alloyed within their structure
3,5-dicaffeoylquinic acid lowers 3T3-L1 mitotic clonal expansion and adipocyte differentiation by enhancing heme oxygenase-1 expression
Adipogenesis is a complex process in which cell commitment and mitotic clonal expansion (MCE) are in-sequence crucial events leading to terminal adipocyte differentiation. The molecules able to block some key signals in this cascade can hamper adipogenesis becoming promising agents to counteract hyperplasia and hypertrophy of adipose tissue. Mono- and di-caffeoylquinic acid isomers are biologically active polyphenols, displaying in vitro and in vivo antioxidant, hepatoprotective, anti-diabetic and anti-obesity properties. Among these isomers, 3,5-dicaffeoylquinic acid (DCQA) has been reported to inhibit lipid accumulation in adipose cells more successfully than others. Thus, we investigated DCQA effects and molecular mechanisms on 3T3-L1 pre-adipocytes induced to differentiate with a hormonal cocktail (MDI). Oil Red O incorporation assessed that DCQA pre-treatment inhibited lipid accumulation in 3T3-L1 cells induced to differentiate for 10 days. At this time, an increased phosphorylation of both AMP-activated kinase and acetyl-CoA carboxylase, as well as a strong decrease in fatty acid synthase protein level, were registered by immunoblotting, thereby suggesting that DCQA treatment can reduce fatty acid anabolism in 3T3-L1 adipocytes. Furthermore, BrdU incorporation assay, performed 48 h after hormonal stimulation, revealed that DCQA treatment was also able to hinder the 3T3-L1 cell proliferation during the MCE, which is an essential step in the adipogenic process. Thus, we focused our attention on early signals triggered by the differentiation stimuli. In the first hours after hormonal cocktail administration, the activation of ERK1/2 and Akt kinases, or CREB and STAT3 transcription factors, was not affected by DCQA pre-treatment. Whereas 24 h after MDI induction, DCQA pre-treated cells showed increased level of the transcription factor Nrf2, that induced the expression of the antioxidant enzyme heme oxygenase 1 (HO-1). In control samples, the expression level of HO-1 was reduced 24 h after MDI induction in comparison with the higher amount of HO-1 protein found at 2 h. The HO-1 decrease was functional by allowing reactive oxygen species to boost and allowing cell proliferation induction at the beginning of MCE phase. Instead, in DCQA-treated cells the HO-1 expression was maintained at high levels for a further 24 h; in fact, its expression decreased only 48 h after MDI stimulation. The longer period in which HO-1 expression remained high led to a delay of the MCE phase, with a subsequent inhibition of both C/EBP-α expression and adipocyte terminal differentiation. In conclusion, DCQA counteracting an excessive adipose tissue expansion may become an attractive option in obesity treatment
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