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La Democrazia Deliberativa
No full textQuesta tesi è dedicata ad una ricostruzione critica dell'idea di democrazia deliberativa. Presento dapprincipio il dibattito sviluppatosi negli ultimi tre decenni attorno alla nozione. Un discorso diffuso attraverso diversi ambiti disciplinari, dalla filosofia alle scienze politiche empiriche, di cui manca finora una ricostruzione sufficientemente approfondita. Nella seconda e più ampia parte della tesi analizzo diversi nuclei tematici attorno ai quali si sono sviluppati gli approcci deliberativi – le ragioni di fondo per deliberare, la concezione della società civile, la definizione dei soggetti e degli oggetti della deliberazione, l'inclusione nella democrazia, il potere comunicativo – delineando gradualmente una ricostruzione più coerente della teoria, caratterizzata da un proceduralismo radicalmente deontologico attraverso il quale, soltanto, è possibile cogliere il senso per cui la partecipazione alla deliberazione pubblica rappresenta la logica intrinseca della democrazia, contro le sempre presenti tendenze tecnocratiche e/o demagogiche
Le droit d'asile dans la région euro-méditerranéenne: entre souveraineté territoriale et droits de l'homme
No full textThe evolution of the international community currently seems to alternate progressive impulses towards greater protection of human rights and sudden fallout in the traditional concept of territorial sovereignty. In a stage characterized by an increasingly restrictive admission of foreign nationals within the borders of the State and collective expulsions, what is the scope of the secular institution of asylum?
Whether, on the one hand, the right of asylum is one of the state powers to freely adjust the entry and stay of aliens on its territory, considered as a corollary of territorial sovereignty, from the viewpoint of the individual it would constitute a means of further guarantee for fundamental rights. From this dilemma between state interest and human rights the present study will move to trace a possible balance between the protection of national security and the protection of human rights in one of the regions most affected by international migrations, like the euro-Mediterranean region. For these reasons, the hypothesis in this dissertation is the existence of a right of individuals to be granted asylum under International Human Rights and Refugee Law.
The premise for this research is necessarily the assertion that individuals may be, even though only in part, subjects of International Law, as right holders vis-a-vis States. In conclusion, it is noted that attempts to claim a fundamental right to asylum, where have not engendered ad hoc set of laws, standing in provisions “still confused and often rudimentary”, they have contributed to conceive the right to asylum as a human right of subsidiary nature, likely to complete other inalienable rights, such as the right to life and physical integrity.The research is divided into 2 parts, including 2 chapters respectively. The first chapter develops the traditional theoretical framework under which the work is conducted. It examines the evolution of asylum through traditional international law and the study comes to identify, in the gradual emergence of a humanitarian nature of asylum, the symptoms of a change in the approach to such legal institution. The second chapter further elaborates on the possible evolution of asylum as a human right, assessing the course of non-refoulement and the jurisprudential contribution of the human rights treaty-monitoring bodies to the acceptance of a right to de facto asylum. The third chapter examines the legal developments in the field of asylum in the European Union, and how this special 'supra-national' legal order relates to the rights of refugees under International Refugee and Human Rights Law. The fourth chapter examines the legal conception of asylum in some other international organizations and legal systems of the Mediterranean and highlights the risks for an effective asylum-seeker protection, hidden in some bilateral readmission agreements
Combining shape and color: a bottom-up approach to evaluate object similarities
No full textThe objective of the present work is to develop a bottom-up approach to estimate the similarity between two unknown objects. Given a set of digital images, we want to identify the main objects and to determine whether they are similar or not. In the last decades many object recognition and classification strategies, driven by higher-level activities, have been successfully developed. The peculiarity of this work, instead, is the attempt to work without any training phase nor a priori knowledge about the objects or their context. Indeed, if we suppose to be in an unstructured and completely unknown environment, usually we have to deal with novel objects never seen before; under these hypothesis, it would be very useful to define some kind of similarity among the instances under analysis (even if we do not know which category they belong to).
To obtain this result, we start observing that human beings use a lot of information and analyze very different aspects to achieve object recognition: shape, position, color and so on. Hence we try to reproduce part of this process, combining different methodologies (each working on a specific characteristic) to obtain a more meaningful idea of similarity. Mainly inspired by the human conception of representation, we identify two main characteristics and we called them the implicit and explicit models. The term "explicit" is used to account for the main traits of what, in the human representation, connotes a principal source of information regarding a category, a sort of a visual synecdoche (corresponding to the shape); the term "implicit", on the other hand, accounts for the object rendered by shadows and lights, colors and volumetric impression, a sort of a visual metonymy (corresponding to the chromatic characteristics).
During the work, we had to face several problems and we tried to define specific solutions. In particular, our contributions are about:
- defining a bottom-up approach for image segmentation (which does not rely on any a priori knowledge);
- combining different features to evaluate objects similarity (particularly focusiing on shape and color);
- defining a generic distance (similarity) measure between objects (without any attempt to identify the possible category they belong to);
- analyzing the consequences of using the number of modes as an estimation of the number of mixture’s components (in the Expectation-Maximization algorithm)
COMPARATIVE BIOLOGY OF THE MAIN ITALIAN CAVE – DWELLING LEPIDOPTERA DURING THEIR SUBTERRANEAN ECOPHASE
No full textSmall scale hybrid concentrated solar power - biomass system. Development, time dependent modelling and validation.
No full textProceeding from the sustainable development principle and the current energy issues, in the present work a small-scale fully renewable power plant was designed, modelled in a time-dependent environment and validated. The plant is design in order to produce both thermal and electric power either in on- or off-grid configuration.
With respect to the state of the art, the power plant is composed by standard and well-known technologies. The novelties brought with the present study are entailed in the arrangement and size of the technologies themselves. Thus the selected parabolic trough solar field is a small size one, i.e. 1,2 MW, on the contrary of the usual multi-MW design. Moreover, the solar section is co-powered with a biomass furnace in place of the typical fossil fuel power generators. Finally, a steam engine is used in a saturated steam Rankine cycle substituting the most common configuration based on steam turbine and superheated steam cycle.
In order to properly evaluate the plant performances, a time-dependent simulation tool was used, allowing to take into account the meteorological variations during a one year period, which has a direct influence on the solar field, affecting the whole system behaviour.
Three different working configurations were proposed, with the aim to assess the plant flexibility to different working conditions, e.g. off-grid or grid-connected. In particular the proposed models are a baseline configuration with constant power outputs, an electric or thermal power tracking scenario coupled with end-users load, and a desalt scenario for electric power and desalted seawater production.
The study shows the capability of the plant to follow different managements, demonstrating its suitability to work in several environments, thus it is effectively reproducible in different countries
Astensionismo nei modelli di competizione politica spaziale e posizionamento strategico dei partiti. Astensione dal voto per indifferenza e per alienazione.
No full textIl presente lavoro introduce la possibilità di astensione dal voto nel modello di competizione politica spaziale à la Downs (1957), con l’intento di analizzare in che modo le decisioni di partecipazione/astensione, congiuntamente alla distribuzione degli elettori lungo lo spazio politico, influenzano il posizionamento strategico dei partiti e, quindi, l’equilibrio politico. In particolare, dopo una rassegna dei più interessanti contributi esistenti in letteratura, proposti come casi speciali di un unico modello generale, il lavoro si concentra sull’astensione da alienazione analizzando la relazione intercorrente tra le piattaforme elettorali in equilibrio, la tolleranza degli elettori e la loro distribuzione lungo l’intervallo di politiche. Infine, lo studio empirico sulla partecipazione al voto degli elettori nelle elezioni politiche italiane del 2008 mira ad individuare la relazione tra le caratteristiche individuali (socio-demografiche, attitudinali, di percezione del sistema politico) e la propensione all’astensione per indifferenza e/o alienazione, nonché ad esaminare la componente di astensione politica, ovvero verificare come l’impatto relativo di alienazione e indifferenza sull’astensionismo sia influenzato dalle posizioni politiche (ideologiche, dato il contesto uni-dimensionale) dei candidati
Mechanisms of Neuroadaptation and the Regulation of Cognition
No full textPerirhinal cortex plays a key role in processing recognition memory. Evidences that repeated exposure to familiar objects produces a decremental response in perirhinal neurones led to the proposal that recognition memory depends on long-term depression. However, long-term potentiation is also expressed in perirhinal cortex. Long-term potentiation is thought to be involved in many form of synaptic plasticity, especially learning and memory. Nevertheless, not much is known on mechanisms maintaining late-phases of long-term depression in perirhinal cortex.
This study shows that LTP in adult perirhinal cortex is maintained by the persistent activity of Protein Kinase Mζ. The inhibition of PKMζ, in fact, completely reverts an established potentiation. This work also focuses on mechanisms that could regulate the persistent activation of PKMζ in perirhinal cortex. The results of the experiments show that synaptic depotentiation appear to down-regulate the activity of PKMζ. Also, the role of PDK1 in regulating the activity of PKMζ is studied. The experiments run provide evidences that the inhibition of PDK1 leads to a decrease of the activity of PKMζ.
This work also explores the mechanisms of synaptic plasticity occurring in perirhinal cortex early in the development. Starting from the observation that it’s not possible to induce LTP in P14 animals, and the only form of potentiation obtainable in P14 perirhinal cortex is de-depression, several experiments have been run to investigate the possible mechanisms underlying this “high levels” of basal synaptic transmission at this stage. PKMζ maintains long-term synaptic potentiation; in P14 perirhinal cortex, the application of the selective PKMζ inhibitor ZIP decreases basal synaptic transmission, but has no effect once LTD has been induced. Moreover, ZIP decreases synaptic transmission in a previously de-depressed pathway,
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providing evidences that in P14 perirhinal cortex LTP mechanisms are present but already saturated in a PKMζ-dependent way. This potentiation of the basal synaptic transmission is lost later during the neurodevelopment (i.e. at PND35); at this stage it is possible to induce LTP in perirhinal cortex, and the inhibition of PKMζ completely reverts the potentiation.
Mechanisms regulating the sustained activity of PKMζ in P14 perirhinal cortex are also examined in this work. New PKMζ is synthesized following the induction of LTP via intracellular mechanisms involving different kinases (i.e. PI3K) and ultimately mTOR-dependent translation. The inhibition of PI3K and mTOR in P14 perirhinal cortex produces a PKMζ-dependent decrease in the basal synaptic response. Therefore, our results suggest that synaptic transmission in immature connections in perirhinal cortex relies on PI3K-, mTOR- and PKMζ-dependent mechanisms. Further experiments show that these processes could be regulated by a continuous activity of Group I mGluRs.
Taken together, these results highlight the crucial role of PKMζ in the synaptic potentiation, and suggest that its sustained activity is required to stabilize young synapses during the neurodevelopment.MRC Centre for Sinaptic Plasticity; Università di Catania; University of Bristo
INVOLVEMENT OF OXIDATIVE STRESS IN THE PATHOGENESIS OF SCHIZOPHRENIA:FOCUS ON NOX ENZYMES
No full textThe imbalance between the production of reactive oxygen species (ROS) and the cellular
antioxidant defence, determines a situation called “oxidative stress”. ROS react and oxidize
cellular components, such as proteins or DNA, leading to cell death and severe tissue damage.
The central nervous system (CNS) is particularly sensitive to oxidative stress because of high
oxygen consumption, low antioxidant defense and abundance of lipids, which are prone to
oxidation. For this reason a variety of CNS diseases have an oxidative stress component. In the
CNS, NOX NADPH oxidases are increasingly recognized as major sources of ROS. Among the
seven existing isoforms, the presence of NOX1, NOX2, NOX3 and NOX4 transcripts has been
detected in total brain samples. In addition, several immunohistological and in vitro studies
have investigated the expression of NOX isoforms in specific CNS regions and cells. From
these studies, it appears that NOX1, NOX2 and NOX4 are present in microglia, neurons and
astrocytes. Although the physiological role of constitutive NOX expression in the brain is still
poorly understood, several researches suggest that they are involved in brain development
and function, but most studies indicate that an excessive production of ROS by NOX enzymes
participates to the progression of various neurological and psychiatric diseases. The aim of this
research project was to investigate the role of NOX2 in the pathogenesis of schizophrenia