5-azacytidine reactivates pluripotency gene expression, affects TET2 and histone transcription and modifies chromatin organization and morphology of mammal skin fibroblasts

Phenotype expression is controlled by epigenetic regulations that guide cells through differentiation.The process is reversible and cells can be driven back to a higher plasticity state with the use ofepigenetic modifiers. In this work we exposed skin fibroblasts to the demethylating agent 5-azacytidine(5-aza-CR), which is a well-known DNA methyltransferase inhibitor, and has been recently shown toincrease cell plasticity and facilitate phenotype changes in different cell types (Pennarossa, 2013; Brevini,2014; Pennarossa, 2014; Brevini, 2016). Although many aspects controlling its demethylating action havebeen widely investigated, the mechanisms through which 5-aza-CR acts on cell plasticity are still poorlyunderstood. At the end of 5-aza-CR treatment, cells were divided in three experimental groups andcultured for 24 and 48 hours: A) cells were returned in standard fibroblast medium; B) cells werecultured in medium specific for pluripotency maintenance; C) cells were placed in a mediumencouraging pancreatic differentiation. At the end of the culture period, as expected, we could observea global demethylating effect. In parallel, however we detected a transient upregulation of thepluripotency genes OCT4, NANOG and REX1. Increased transcription of TET2 and histones belonging tothe 1,2,3 and 4 families, together with changes in the expression of enzymes controlling histoneacetylation were also appreciated. Interestingly, these results were accompanied by morphological andultrastructural changes as well as by chromatin structure modifications. All together our findingsindicate that 5-aza-CR induced somatic cell transition to a higher plasticity state involves novel cellulartargets that activate multiple epigenetic regulatory pathways

Last minute policies and the incumbency advantage

This paper models a purely informational mechanism behind the incumbency advantage. In a two-period electoral campaign with two policy issues, a specialized incumbent and an unspecialized, but possibly more competent challenger compete for election by voters who are heterogeneously informed about the state of the world. Due to the asymmetries in government responsibility between candidates, the incumbent's statement may convey information on the relevance of the issues to voters. In equilibrium, the incumbent sometimes strategically releases his statement early and thus signals the importance of his signature issue to the voters. We find that, since the incumbent's positioning on the issue reveals private information which the challenger can use in later statements, the incumbent's incentives to distort the campaign are decreasing in his quality, as previously documented by the empirical literature. The distortions arising in equilibrium are decreasing in the incumbent's effective ability; however, the distortions may be increasing in the incumbent's reputation of expertise on his signature issue

Target-the-two. A lab-in-the-field experiment on routinization

The paper investigates the cognitive determinants of routinization and creativity by means of a lab-in-the-field experiment run at the 20th edition of a mass gathering festival in Italy (“La Notte della Taranta”). Subjects play repeatedly the puzzle version of the Target-The-Two game (32 hands). In hands 1-16, the strategy that is optimal given the card distribution is always the same and it is the easiest to be discovered. Conversely, in hands 17-32, subjects are exposed to games where the optimal contextual strategy may differ from the one with which they have been made familiar. We investigate whether and how, in hands 17-32, subjects remain routinized on the familiar strategy, or creatively choose a different one. We define as “experts” those subjects who played the optimal contextual strategy in the overwhelming majority of hands 1-16. In hands 17-32, we find several subjects playing the familiar strategy even when it is not the optimal one, regardless of whether they are experts or not. This shows that routinization is deep-rooted in the cognitive individual process. Furthermore, routinization pays off only for inexpert subjects: creative inexpert subjects are slower and they fail to find the optimal contextual strategy in several hands. Among expert subjects instead, creative subjects, although still slower, need less moves than routinized ones to find the optimal contextual strategy

A staggered-in-time and non-conforming-in-space numerical framework for realistic cardiac electrophysiology outputs

Computer-based simulations of non-invasive cardiac electrical outputs, such as electrocardiograms and body surface potential maps, usually entail severe computational costs due to the need of capturing fine-scale processes and to the complexity of the heart-torso morphology. In this work, we model cardiac electrical outputs by employing a coupled model consisting of a reaction-diffusion model - either the bidomain model or the most efficient pseudo-bidomain model - on the heart, and an elliptic model in the torso. We then solve the coupled problem with a segregated and staggered in-time numerical scheme, that allows for independent and infrequent solution in the torso region. To further reduce the computational load, main novelty of this work is in introduction of an interpolation method at the interface between the heart and torso domains, enabling the use of non-conforming meshes, and the numerical framework application to realistic cardiac and torso geometries. The reliability and efficiency of the proposed scheme is tested against the corresponding state-of-the-art bidomain-torso model. Furthermore, we explore the impact of torso spatial discretization and geometrical non-conformity on the model solution and the corresponding clinical outputs. The investigation of the interface interpolation method provides insights into the influence of torso spatial discretization and of the geometrical non-conformity on the simulation results and their clinical relevance.Comment: 26 pages,11 figures, 3 table

Electoral campaigns with strategic candidates: A theoretical and empirical analysis.

The main focus of this thesis is the analysis of political campaigns when candidates choose their statements in a strategic way. In the first chapter, 'Discretion and renegotiation in electoral campaigns', I present a model of electoral campaigning as a problem of competitive delegation. The chapter considers a situation in which there is uncertainty about what the optimal policy should be; in this environment voters may want to leave discretion to a candidate, in order to allow him to adjust his policies to the state of the world, once he is elected. The paper analyses how the ambiguity level of the political statements is influenced by the presence of uncertainty over the candidates' ideology, by the possibility of ex post renegotiation between the elected candidate and the voters and by several political variables. In the second chapter, 'Last minute policies and the incumbency advantage', joint with Stefan Penczynski, we investigate the timing of statements in political debates and campaigns. Early statements can influence the political agenda and signal competence and vision, late statements are based on more information about appropriate measures. We find that candidates speak early on issues they are better-informed about in order to signal relevance and move them up the agenda. Since opponents benefit from this revelation, however, candidates remain silent once their information is sufficiently precise and valuable. In the last chapter, 'Discretion and ambiguity in electoral campaigns: a look into the empirical evidence', I compare several models of ambiguity in electoral campaigns, including my own model which was introduced in the first chapter. I use the methodology of Campbell (1983) to have a proxy for ambiguity of the electoral statements, and the data from the American National Election Studies on Senate elections from 1988-1990-1992, to investigate which of the correlations predicted by these models seem to be present in the data

Women at work: Gender quotas, municipal elections and local spending

Gender quotas should foster women’s presence in politics, which in turn may affect local poli- cymaking. This paper investigates this mechanism, considering indicators of municipality spending in Italy as relevant policy outcomes. For identification, we rely on the time and geographic variation in the introduction of a gender quota reform by Law 215/2012. The reform affected gender composition of candidates in Italian municipal council elections, resulting in an increase of the share of female councilors of about 13.9 percentage points. Using the reform as an instrument, we estimate that a one percentage point increase in female participation in councils rises expenditure for local security by about 1% and reduces administration costs by a comparable amount, whereas evidence on the impact on other local expenditure items is mixed and not significant. Estimated effects are associated with compositional changes in terms of employment status of female councilors and are robust to endogeneity issues, to relevant sample selections and to the implications of confounding policies

Voters\u2019 preferences and electoral systems: the EuroVotePlus experiment in Italy

Motivated by the need to understand voting behaviour under different electoral rules, Laslier et al. (Eur Union Polit, 16(4):601\u2013615, 2015) have conducted an online experiment, the EuroVotePlus experiment, focusing on the effects of the different rules adopted to elect members of the European parliament on voters\u2019 behaviour. The experiment took place in several European countries in the 3 weeks before the 2014 elections for the European Parliament. This paper focuses on the Italian data. Firstly, we show that the behaviour of Italian respondents is consistent with the empirical findings at the European level. Then, we exploit the change from open list to closed list elections implemented in Italy in 1993 to investigate whether and how preferences over institutions are affected by experience. We find that respondents who voted using the open list system in Italy are more likely to prefer closed list systems, and that the effect is stronger the higher the number of open list elections the respondents have faced

Liquid Marble micro-bioreactor promotes 3D cell rearrangement and induces, maintains and stabilizes high plasticity in epigenetically erased fibroblasts

In the last years, many works demonstrated the possibility to directly interact with the epigenetic signature of an adult mature cell, through the use of epigenetic modifiers, (Pennarossa et al., 2013; Brevini et al., 2014, Chandrakantan et al., 2016) and new mechanisms underlying this process have been recently described (Manzoni et al., 2016). In particular, the small molecule 5-azacytidine (5-aza-CR) has been shown to induce a transient higher plasticity state in adult somatic cells, grown in standard 2D conditions. Recent evidence have also shown the possibility to regulate and maintain cell pluripotency through the use of 3D culture systems. In the experiments here presented, we combine the two approaches and investigate whether the simultaneous use of a 3D micro-bioreactor and 5-aza-CR is able to promote cell rearrangement, boost the induction of high plasticity and stably maintain it.To this purpose, fibroblasts were either plated on plastic dishes (2D) or encapsulated in a Liquid Marble (LM) micro-bioreactor (polytetrafluoroethylene (PTFE)), which has been previously shown to support the growth of living microorganisms, tumor spheroids, fibroblasts, red blood cells, and embryonic stem cells (Ledda et al., 2016). Cells were then erased with 5-aza-CR, for 18 hours and cultured in Embryonic Stem Cell (ESC) medium for up to 28 days. Morphological analysis and pluripotency related gene expression levels were monitored for the entire length of the experiments. 2D cells, kept a monolayer pattern and acquired a pluripotent state that was, however, transient and lost by day 6. In contrast the use of a 3D system maintained and stabilized the high plasticity state in LM cells until the end of the experiments (Fig. 1). The data obtained demonstrate that cell rearrangement and interactions may modulate 5-aza-CR induced plasticity and suggest a correlation between 3D mechano-transduction-related pathways and  epigenetic regulation of cell phenotype