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Tutela dell'incolumità pubblica dall'aggressività dei cani. Nota 1. Le ordinanze 9 settembre 2003 e 10 settembre 2004 e l’ordinanza 3 ottobre 2005
No full textRIASSUNTO Dal 2003 ad oggi sono state emanate dai diversi Ministri della salute quattro Ordinanze sui cosiddetti “cani pericolosi”, ognuna della durata di un anno, ognuna rinnovata senza che in tutto questo tempo, nonostante la dichiarata necessità, venisse approvata una normativa organica sull’argomento. Gli Autori in questa prima nota esaminano le Ordinanze 9 settembre 2003 e 10 settembre 2004 (così dette Ordinanze Sirchia) e l’Ordinanza 3 ottobre 2005, così detta Ordinanza Storace, con le quali è stata approntata una lista di razze considerate pericolose, per le quali vengono stabilite regole particolari. L’elenco dei cani considerati potenzialmente “pericolosi”, però, si sfoltisce col trascorrere degli anni tanto che dal primo elenco dell’Ordinanza 9 settembre 2003 dove figuravano tutti i cani appartenenti al gruppo 1 e 2 della classificazione ENCI si arriva alla lista dell’Ordinanza 3 ottobre 2005 che ne comprende solo 17: American bulldog, cane da pastore di Charplanina, cane da pastore dell’Anatolia, cane da pastore dell’Asia centrale, cane da pastore del Caucaso, cane da Serra da Estreilla, Dogo Argentino, Fila brazileiro, Perro da canapo majoero, Perro da presa canario, Perro da presa Mallorquin, Pit bull, Pit bull mastiff, Pit bull terrier, Rafeiro do alentejo, Rottweiler, Tosa inu. SUMMARY The different ministers of the health have emanated four Ordinances regarding the so called “dangerous dogs” from 2003 till to today. Every Ordinance, lasting only for one year, has been renewed during years with some variations, in spite of the declared necessity of a normal low approved by the parliament. The authors in this first note examine the Ordinance September, 9 2003, September, 10 2004 (Sirchia Minister) and October, 3 2005 (Storace Minister) in which the list of dangerous dog breeds has been made with the aim to establish particular rules for the management of these dogs. The number of dog breeds in the list was progressively reduced in the renewed Ordinances that followed the first done. Every dog breed bearing to the group 1 and 2 of the ENCI classification had been inserted in the Ordinance dated September, 9 2003 and only the following 17 dog breeds were inserted in the Ordinance dated October, 3 2005: American bulldog, Charplanina Sheepdog, Anatolian Shepherd Dog, Central Asian Sheepdog, Caucasian Sheepdog, Cão da Serra da Estrela, Dogo Argentino, Fila brazileiro, Perro da canapo majoero, Perro da presa canario, Perro da presa Mallorquin, Pit bull, Pit bull mastiff, Pit bull terrier, Rafeiro do alentejo, Rottweiler, Tosa inu
Tra l'esempio e l'eccezione: Pisa negli studi di Gabriella Rossetti
No full textRIASSUNTO Analisi degli studi fatti da Gabriella Rossetti sulla città di Pisa nel medioevo. SUMMARY Essay on studies and writings nade by Gabriella Rossetti about the city of Pisa in the Middle Age
Il corsaro pisano Trapelicino: un’avventura mediterranea del XII secolo
No full textSUMMARY This article reconstructs the vicissitudes of a Pisan crew navigating the coasts of the Mediterranean in the second half of the twelfth century. The analysis is based on a variety of sources, dispersed in several Mediterranean archives, that shed light on the outfitting of a corsair ship, on the way in which decisions were made on a medieval ship, and on the existence of mixed Christian and Muslim crews on board the ships of major European Mediterranean cities such as Pisa
Observation of photon-assisted tunneling in optical lattices
No full textWe have observed tunneling suppression and photon-assisted tunneling of
Bose-Einstein condensates in an optical lattice subjected to a constant force
plus a sinusoidal shaking. For a sufficiently large constant force, the ground
energy levels of the lattice are shifted out of resonance and tunneling is
suppressed; when the shaking is switched on, the levels are coupled by
low-frequency photons and tunneling resumes. Our results agree well with
theoretical predictions and demonstrate the usefulness of optical lattices for
studying solid-state phenomena
Succinct Oracles for Exact Distances in Undirected Unweighted Graphs
No full textLet G be an unweighted and undirected graph of n nodes, and let D be the n x n matrix storing the All-Pairs-Shortest-Path distances in G. Since D contains integers in [n], its plain storage takes n^2log (n + 1) bits. However, a simple counting argument shows that n^2/2 bits are necessary to store D. In this paper we investigate the question of finding a succinct representation of D that requires O(n^2) bits of storage and still supports constant-time access to each of its entries. This is asymptotically optimal in the worst case, and far from the information-theoretic lower-bound by a multiplicative factor log 3 \simeq 1.585. As a result O(1) bits per pairs of nodes in G are enough to retain constant-time access to their shortest-path distance. We achieve this result by reducing the storage of D to the succinct storage of labeled trees and ternary sequences, for which we properly adapt and orchestrate the use of known compressed data structures
Deflected Conditional Approximate Subgradient Methods
No full textSubgradient methods for constrained nondifferentiable problems benefit from projection of the search direction onto the (normal cone of) the feasible set prior to computing the steplength, that is, from the use of conditional subgradient techniques. In general, subgradient methods also largely benefit from deflection, i.e., defining the search direction as a (convex) combination of the previous direction and the current subgradient. However, combining the two techniques is not straightforward, especially if an inexact oracle is available which can only compute approximate function values and subgradients. We present a convergence analysis of several different variants, both conceptual and implementable, of approximate conditional deflected subgradient methods. Our analysis extends the available results in the literature by using the main stepsize rules presented so far while allowing deflection in a more flexible way; to allow for (diminishing/square summable) rules where the stepsize is tightly controlled a-priori, we propose a new class of deflection-restricted approaches where it is the deflection parameter, rather than the stepsize, which is dynamically adjusted using the "target value" of the optimization sequence. For both Polyak-type and diminishing/square summable stepsizes, we propose a "correction" of the standard formula which shows that, in the inexact case, knowledge about the error computed by the oracle (which is available in several practical applications) can be exploited in order to strengthen the convergence properties of the method
Dual superconductivity and vacuum properties in Yang--Mills theories
No full textWe address, within the dual superconductivity model for color confinement,
the question whether the Yang-Mills vacuum behaves as a superconductor of type
I or type II. In order to do that we compare, for the theory with gauge group
SU(2), the determination of the field penetration depth with that of
the superconductor correlation length . The latter is obtained by
measuring the temporal correlator of a disorder parameter developed by the Pisa
group to detect dual superconductivity. The comparison places the vacuum close
to the border between type I and type II and marginally on the type II side. We
also check our results against the study of directly measurable effects such as
the interaction between two parallel flux tubes, obtaining consistent
indications for a weak repulsive behaviour. Future strategies to improve our
investigation are discussed
Analytic continuation from imaginary to real chemical potential in two-color QCD
No full textThe method of analytic continuation from imaginary to real chemical potential
is one of the most powerful tools to circumvent the sign problem in lattice
QCD. Here we test this method in a theory, 2-color QCD, which is free from the
sign problem. We find that the method gives reliable results, within
appropriate ranges of the chemical potential, and that a considerable
improvement can be achieved if suitable functions are used to interpolate data
with imaginary chemical potential
On the moduli space of semilocal strings and lumps
No full textWe study BPS non-abelian semilocal vortices in U(Nc) gauge theory with Nf
flavors, Nf > Nc, in the Higgs phase. The moduli space for arbitrary winding
number is described using the moduli matrix formalism. We find a relation
between the moduli spaces of the semilocal vortices in a Seiberg-like dual
pairs of theories, U(Nc) and U(Nf-Nc). They are two alternative regularizations
of a "parent" non-Hausdorff space, which tend to the same moduli space of
sigma-model lumps in the infinite gauge coupling limits. We examine the
normalizability of the zero-modes and find the somewhat surprising phenomenon
that the number of normalizable zero-modes, dynamical fields in the effective
action, depends on the point of the moduli space we are considering. We find,
in the lump limit, an effective action on the vortex worldsheet, which we
compare to that found by Shifman and Yung
Dall'ingegneria empirica verso l'ingegneria della scienza: la perizia di tre Matematici per la Cupola di San Pietro (1742)
Get PDFRIASSUNTO Gli studi riguardanti il comportamento meccanico delle cupole, derivati dall'analisi statica degli archi e delle volte, muovevano i primi passi nella prima metà del XVIII secolo quando, sul finire del 1741, Benedetto XIV commissionò una perizia ai Matematici Ruggiero Giuseppe Boscovich, Francesco Jaquier, Tommaso Le Seur della "Repubblica Romana dei Dotti". Erano sorte infatti serie preoccupazioni per le condizioni statiche della cupola di San Pietro, nella quale si erano manifestate importanti lesioni. Sull'argomento si erano già sviluppati altri interessanti studi, accompagnati da eruditi ed accesi dibattiti, che avevano condotto alla redazione di veri e propri trattati, finalizzati anche all'ordinamento delle conoscenze sull'argomento. I documenti storici riportano i pareri di altri studiosi, come quello ben noto del matematico padovano Giovanni Poleni. Lo studio dei tre Matematici si distingueva però per un'importante singolarità innovativa; si trattava infatti di una perizia condotta applicando, forse per la prima volta, un criterio scientifico allo scopo di interpretare il comportamento meccanico di un manufatto architettonico. La sua importanza storica consiste nel fatto che, contrariamente alle consuetudini delle epoche precedenti, basate su regole empiriche, tutto al più di natura geometrica, si fanno intervenire concezioni teoriche, questa volta di natura scientifica, per l'analisi di un problema strutturale. Nella perizia fu applicato, sia pure in una forma non sempre perfetta, il principio dei lavori virtuali, utilizzandolo come strumento per il dimensionamento degli anelli metallici da applicare al tamburo della cupola. Alcuni studiosi, per cercare una data significativa, indicano questa perizia come il momento in cui è avvenuto il passaggio da un'ingegneria fondata su tradizioni artigianali ad un'ingegneria basata sull'applicazione delle nuove teorie scientifiche che iniziavano allora ad affermarsi. SUMMARY This lesson talks about the examination of the mechanical movements of the San Pietro's dome ordered by Benedetto XIV to three maths: Ruggiero Giuseppe Boscovich, Francesco Jaquier and Tommaso Le Seur. The report is very innovative because for the fist time mathematical theories were applied to architecture