322,834 research outputs found
Il Conseil constitutionnel, terzo motore del potere di emendamento nel procedimento legislativo francese
No full textLa ricerca di quest’anno del Seminario di Studi e Ricerche Parlamentari “S. Tosi” ha avuto ad oggetto un tema classico del diritto parlamentare, quello degli emendamenti. Un tema, da sempre, studiato dalla dottrina costituzionalistica italiana per la sua centralità nelle dinamiche dei procedimenti normativi, ma anche per la sua capacità di fornire interessanti chiavi di lettura del funzionamento della forma di governo parlamentare. Coerentemente con il metodo costantemente praticato dal Seminario, la ricerca ha riguardato l’ordinamento costituzionale italiano, con due distinti focus, uno relativo al diritto parlamentare e uno relativo al diritto regionale, e due esperienze di diritto comparato, quella francese e quella spagnola, che appaiono complementari rispetto a quella italiana per le diverse caratteristiche della forma di stato e della forma di governo che contraddistinguono quegli ordinamenti
LA SALVAGUARDIA DEL RICCIO DI MARE PUGLIESE: DA UN SINGOLO CASO, ALLA TUTELA COSTITUZIONALE E SOVRANAZIONALE DELLE RISORSE BIOLOGICHE MARINE.
No full textAttraverso la menzione di “biodiversità” nell’innovato art. 9 Cost. si potrebbe ritenere che tale elemento risulti oggi fondamentale per l’ordinamento giuridico italiano tutto. Alla luce di una mutata sensibilità internazionale e nazionale si deve, quindi, verificare se effettivamente l’Italia intenda tutelare quest’aspetto. A tal fine, pare di speciale rilievo la questione, giunta all’attenzione della Corte costituzionale, oggetto del giudizio di legittimità costituzionale in via principale riguardante il divieto, introdotto dalla Regione Puglia, di prelievo, raccolta, detenzione, trasporto, sbarco e commercializzazione degli esemplari di riccio di mare e dei relativi prodotti derivati freschi, procacciati nei mari regionali, per un periodo di tre anni. L’obiettivo della disposizione censurata pare risiedere nella volontà di scongiurare il rischio di estinzione della fauna delle suddette aree marine, ma tale obiettivo – per quanto nobile – ha suscitato non poche perplessità, rischiando di porsi in violazione sia dell’art. 117, c. 2., lett. s) Cost., con riguardo alla materia di competenza esclusiva “tutela dell’ambiente e dell’ecosistema”. La soluzione di questo caso appare significativa, soprattutto se si considera l’importanza degli interessi pubblici in gioco, da bilanciarsi cautamente. Adottando, quindi, un approccio di law and literature, si può partire dalla centralità che la Natura, in tutte le sue forme e declinazioni, assume nell’opera dello scrittore Tolkien, che sembra aver prefigurato un possibile “pregiudizio ecologico”, legato all’eccessivo ricorso all’industria e ai rilevanti cambiamenti climatici. Considerando, quindi, la normativa europea, nazionale e regionale sul punto, attraverso la risoluzione del caso pugliese, si possono trarre importanti conclusioni di sistema in tema di garanzia della fauna marina in un ecosistema protetto, nel complesso intreccio di competenze delineatosi
Shadow bands, gap and pseudogap in high-Tc superconductors
No full textWithin the framework of the Charge Density Wave Quantum Critical Point (CDW-QCP] scenario for high-Tc superconductors (HTCS) we introduce a model for tight-binding electrons coupled to quasi-critical fluctuations. In the normal state our model reproduces features the Fermi Surface (FS) observed in ARPES measurements on optimality doped Bi2212, such as the anisotropic suppression of spectral weight around the M points of the Brillouin zone. The spectral density is characterized by a transfer of spectral weight from the main quasiparticle peak to dispersing shadow peaks which originate branches of a shadow FS. In the superconducting state our model reproduces the d-wave symmetry of the gap parameter, which results from a balance between small-q attraction and large-q repulsion. The gap parameter is enhanced due to cooperative effects of charge and spin fluctuations
INSEDIAMENTO ED INTERVENTI PER L’EMERGENZA: UN MODELLO DI CONTROLLO DI ACCESSO AL TERRITORIO
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Ab initio studies of targets for pharmaceutical intervention
No full textIn this thesis we further explore the capability of first principle methods to provide
insights on drug/target interactions in different contexts.
In the first part of this work, we address the issue whether OFT methods can be used as
a potential tool for drug-screening. First principle calculations are particularly interesting
for screening the energetics of drug/target interactions, as they do not involve the
painstaking procedure of developing each set of new parameters for each novel drug. In
this context, we use ab initio_ methods as a novel tool to determine a scoring function in a series of prodrug I target (herpes simplex type 1 thyimidine kinase) complexes for
gene-therapy based anticancer approaches. This work, accompanied by experimental
data provided by Prof. Folkers' Lab (ETH, Zurich) provides a new, very simple, ab initiobased
approach to the construction of scoring functions for drug-screening.
In the second part of the thesis we investigate the capability of OFT to describe non
trivial interactions which are encountered in several inhibitor/enzyme complexes of
pharmaceutical interest. Clearly, the description of these non-trivial phenomena might
require the use of electronic structure methods. Here we present an example of cation-n
interaction found in the human immunodeficiency virus reverse transcriptase (HIV-1
RT), one of the major targets for anti-AIDS therapy(Furman et al., 2000)). Furthermore,
we provide a description of the hydroxyl-n interactions in the active site of μ-glutathione
S-transferase(Xiao et al., 1996) (μ-GST), whose differential expression has been
implicated in the development of cancers as well as their resistance to
chemotherapeutic drugs ((Mccallum et al., 2000) and reference therein).
Finally we present a classic problem treated by quantum-chemical methods: the
simulation of an enzymatic reaction. We focus on a class of cysteine proteases, the
caspases. These enzymes are extremely important targets for pharmaceutical
intervention in therapies against Alzheimer's and other neurodegenerative processes,
yet very few inhibitors have been so far designed. Since an important class of inhibitors
is the given by the transition state analogs, it is of importance to fully understand the ·
enzymatic reaction, that is the hydrolysis of peptides. Because of the crucial importance
of temperature and environment(Karplus, 2000; Glennon and Warshel, 1998; Varnai
and Warshel, 2000; Villa et al., 2000) effects for enzymatic catalysis, we use here a
hybrid Car-Parrinello Molecular dynamics I Molecular mechanics approach recently
developed in the Lab of Prof. U. Roethlisberger (Laio et al., 2001 ). This technique
allows to evaluate the intermolecular interactions at the active site from electronic
structure calculations as the simulation proceeds(Car and Parrinello, 1985). Steric and
electrostatic effects of the protein scaffold on the quantum region are included using
classical MD approach on the rest of the system. The free energy of the process is
calculated using a thermodynamic integration approach(Ciccotti et al., 1989; Carloni et
al., 2000; Piana et al., 2001). This thesis is organized as follows. The first chapter provides a description of the used
computational techniques. The following chapter describes the systems investigated
here and summarizes our findings. The subsequent three chapters are devoted to a -
detailed description of my thesis work. In a final chapter we draw some conclusions and
provide a perspective for possible future applications, which could follow this work
Nuclear Propulsion Technology for Satellite Applications: Historical Overview and Current Developments
No full textFermi surface and gap parameter in high-Tc superconductors: the Stripe Quantum Critical Point scenario
No full textWe study the single-particle spectral properties of electrons coupled to quasicritical charge and spin fluctuations close to a stripe-phase, which is governed by a Quantum Critical Point near optimum doping. We find that spectral weight is transferred from the quasiparticle peak to incoherent dispersive features. As a consequence, the distribution of low-laying spectral weight is modified with respect to the quasiparticle Fermi surface. The interplay of charge and spin fluctuations reproduces features of the observed Fermi surface, such as the asymmetric suppression of spectral weight near the M points of the Brillouin zone. Within the model, we also analyze the interplay between repulsive spin and attractive charge fluctuations in determining the symmetry and the peculiar momentum dependence of the superconducting gap parameter. When both spin and charge fluctuations are coupled to the electrons, we find dx2−y2-wave gap symmetry in a wide range of parameter. A crossover d- vs. s-wave symmetry of the gap may occur when the strength of charge fluctuations increases with respect to spin fluctuations
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
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