1435 research outputs found
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Un'indagine sui fruitori delle spiagge comprese tra Marina di Vecchiano e Marina di Levante
No full textRIASSUNTO: Il presente lavoro di ricerca ha ad oggetto un’indagine socio-ambientale svoltasi nell’ambito del progetto LIFE – Natura “DUNETOSCA - Conservazione degli ecosistemi costieri nella Toscana settentrionale”, progetto approvato e finanziato dall’Unione Europea. L’indagine che ha coinvolto 186 persone è stata svolta per conoscere il grado di consapevolezza naturalistica dei fruitori delle spiagge comprese tra Marina di Vecchiano e Marina di Levante in vista di un miglioramento ambientale dei siti di interesse comunitario denominati “Selva Pisana” e “Dune Litoranee di Torre del Lago”. SUMMARY: This research work is a social-environment inquiry to know how people, who frequent the Viareggio beach, knows the environment problematic. The research was financed by EU and local administration
The strongly interacting Quark Gluon Plasma, and the critical behaviour of QCD at imaginary chemical potential
No full textWe explore the highly non-perturbative hot region of the QCD phase diagram
close to Tc by use of an imaginary chemical potential mu which avoids the sign
problem. The number density and the quark number susceptibility are consistent
with a critical behaviour associated with the transition line in the negative
mu^2 half-plane. We compare the analytic continuation of these results with
various phenomenological models, none of which provides a satisfactory
description of data, a failure on which we make some comments. These results
complement and extend the information obtained via the analysis of the
susceptibilities evaluated at zero mu, yielding a simple description of the
candidate strongly interacting QGP phase. As a byproduct of our analysis we
investigate the Polyakov loop and its hermitian conjugate. Our data offer a
vivid evidence of the importance of the complex nature of the functional
integral measure, which results in L (mu) ne \bar L(mu) for a real chemical
potential
Dual superconducting properties of the QCD vacuum
No full textA consistent description of the confining QCD vacuum as a dual superconductor
requires a determination of fundamental parameters such as the superconductor
correlation length and the field penetration depth , which
determine whether the superconductor is of type I or type II. We illustrate
preliminary results of a lattice determination of for the case of pure
Yang-Mills with two colors, obtained by measuring the temporal correlator of a
disorder parameter detecting dual superconductivity
Imaginary chemical potentials and the phase of the fermionic determinant
No full textA numerical technique is proposed for an efficient numerical determination of
the average phase factor of the fermionic determinant continued to imaginary
values of the chemical potential. The method is tested in QCD with eight
flavors of dynamical staggered fermions. A direct check of the validity of
analytic continuation is made on small lattices and a study of the scaling with
the lattice volume is performed
The 3D +-J Ising model at the ferromagnetic transition line
No full textWe study the critical behavior of the three-dimensional Ising model
[with a random-exchange probability ] at the transition line between the paramagnetic and
ferromagnetic phase, which extends from to a multicritical (Nishimori)
point at . By a finite-size scaling analysis of Monte Carlo
simulations at various values of in the region , we provide strong
numerical evidence that the critical behavior along the ferromagnetic
transition line belongs to the same universality class as the three-dimensional
randomly-dilute Ising model. We obtain the results and
for the critical exponents, which are consistent with the
estimates and at the transition of
randomly-dilute Ising models
Electric field dynamics and ion acceleration in the self-channeling of a superintense laser pulse
No full textSUMMARY The dynamics of electric field generation and radial acceleration of ions by
a laser pulse of relativistic intensity propagating in an underdense plasma has
been investigated using an one-dimensional electrostatic, ponderomotive model
developed to interpret experimental measurements of electric fields [S. Kar et
al, New J. Phys. *9*, 402 (2007)]. Ions are spatially focused at the edge of
the charge-displacement channel, leading to hydrodynamical breaking, which in
turns causes the heating of electrons and an "echo" effect in the electric
field. The onset of complete electron depletion in the central region of the
channel leads to a smooth transition to a "Coulomb explosion" regime and a
saturation of ion acceleration
Confinement: group case
No full textSUMMARY The gauge group being centreless, gauge theory is a good laboratory for
studying the role of the centre of the group for colour confinement in
Yang-Mills gauge theories. In this paper, we investigate pure gauge
theory at finite temperature on the lattice. By studying the finite size
scaling of the plaquette, the Polyakov loop and their susceptibilities, we show
that a deconfinement phase transition takes place. The analysis of the
pseudocritical exponents give strong evidence of the deconfinement transition
being first order. Implications of our findings for scenarios of colour
confinement are discussed
Resonantly enhanced tunneling of Bose-Einstein condensates in periodic potentials
No full textWe report on measurements of resonantly enhanced tunneling of Bose-Einstein
condensates loaded into an optical lattice. By controlling the initial
conditions of our system we were able to observe resonant tunneling in the
ground and the first two excited states of the lattice wells. We also
investigated the effect of the intrinsic nonlinearity of the condensate on the
tunneling resonances
Home range e utilizzo del territorio in pernici rose (Alectoris rufa rufa L.) nate in allevamento e allo stato selvatico
No full textRIASSUNTO In Italia sono state ricostituite numerose piccole popolazioni di pernici rosse (Alectoris rufa L.) in areali dove la specie era estinta. Allo stato attuale, poiché la dimensione delle popolazioni ricostituite non raggiunge la dimensione minima necessaria per preservare la specie da una nuova estinzione, devono essere programmati interventi di sostentamento con rilascio di animali di altra provenienza. Al fine di utilizzare pernici nate in allevamento è quindi indispensabile effettuare una ricerca per valutare la capacità di integrazione, la sopravvivenza, l’uso dell’habitat e gli home-range di tali animali liberati in aree occupate da neopopolazioni selvatiche. All’interno di una Zona di Ripopolamento e Cattura (Petroio-Vinci-Firenze) dove è presente una popolazione stimata di 60 pernici selvatiche sono state immesse 350 pernici allevate nel mese di agosto. In gennaio sono state quindi catturate 6 pernici allevate e 21 pernici selvatiche. 6 soggetti per tesi (allevate o selvatiche) sono stati quindi radiocollarati e localizzati bisettimanalmente fino a luglio 2006. La mortalità osservata degli animali radiocollarati è risultata identica (50% =3 soggetti per ciascuna tesi) fra i soggetti selvatici ed i pochi soggetti allevati ricatturati che avevano superato l’inverno (mortalità stimata post-rilascio = 95,1%). I soggetti allevati sopravvissuti all’inverno sono stati in grado di integrarsi in brigate miste con quelli selvatici ed anche gli animali allevati sono stati in grado di riprodursi: delle 3 nidiate osservate, 1 apparteneva alla tesi selvatiche e 2 a quella allevate. L’habitat più frequentato dalle pernici è risultato il vigneto non lavorato, mentre l’aumento significativo della distanza dai punti di alimentazione artificiale sussidiari durante la cova ha fornito l’indicazione gestionale di aumentare e disperdere maggiormente le mangiatoie in primavera per compensare la dispersione delle coppie legata alla territorialità naturale. La distanza dalle abitazioni e gli home-range non sono risultati infine differire fra pernici selvatiche e allevate. SUMMARY In Italy several small populations of red-legged partridges (Alectoris rufa L.) has been reconstituted in areas where the species was extinguished. In these areas release of different animals must be programmed, since the dimension of the reconstituted populations does not catch up the minimal dimension required to guard the species from a new extinction. We have thought therefore indispensable to carry out a research in order to estimate the integration ability of the released raised-partridges with the wild population, the survival rates, the use of the habitat and the home-ranges of both populations. In a protected area of Central Italy (Petroio-Vinci-Florence), where an estimated population of 60 wild partridges is estimated, 350 raised partridges were released during the August month. In January 6 raised partridges and 21 wild partridges has been captured by traps. 6 subjects for each thesis (raised or wild) have been therefore equipped with radio necklaces and localised biweekly until July 2006. No difference in mortality rates (50% = 3 birds each) was observed between wild or raised partridges that had survived to the winter (estimated mortality after release = 95.1%). Raised partridges, that survive after their release in the wild, were able to integrate themselves in mixed brigades with the wild partridges. Also the raised partridges were able to breed (of the 3 observed broods of the radiotagged birds 2 belonged to the raised and 1 to the wild). Vineyards with interlined grass were the habitat most frequented (more than 25% of the localizations). The distance from the subsidiary artificial feeding points significantly increased during broods showing the necessity to increase the number and dispersion of the supplementary feeders in spring, to help the animals from an alimentary point of view. The distance from the houses and home ranges surfaces did not differ between wild and raised partridges
L’ernia diaframmatica traumatica nel gatto. Studio retrospettivo su 21 casi (2001-2006)
No full textRIASSUNTO L’ernia diaframmatica traumatica nel gatto è una patologia di notevole interesse clinico e di difficile approccio terapeutico. Con questo studio retrospettivo su 21 casi ci siamo proposti di valutare se segnalamento, durata dell’ernia, segni clinici, contenuto dell’ernia, patologie concomitanti, trattamenti perioperatori o tipo di tecnica d’intervento possano influire sul tasso di mortalità postoperatoria nel trattamento dell’ernia diaframmatica. Abbiamo preso in considerazione i dati clinici delle cartelle mediche di 21 gatti afferiti al Dipartimento di Clinica Veterinaria dell’Università di Pisa nel periodo 2001-2006 cui sia stata diagnosticata ernia diaframmatica traumatica; ed è stato effettuato un follow-up mediante intervista telefonica ai proprietari e ai veterinari referenti. Dal nostro studio risulta che: l’età media dei soggetti visitati era di 3 anni e 4 mesi. Il gatto comune europeo a pelo corto è risultato il più colpito, senza predisposizione legata al sesso. La causa più frequentemente riferita di ernia diaframmatica traumatica è stata l’investimento da parte di veicoli a motore. La dispnea è stato il segno clinico più frequentemente rilevato alla visita. Dei 21 casi valutati, solo 17 sono stati sottoposti ad intervento chirurgico di erniorrafia; 6 di questi sono stati persi al follow-up, 3 sono deceduti (1 per complicazioni intra-operatorie, 2 per aggravamento di patologie concomitanti all’ernia diaframmatica), 2 gatti, a distanza dall’intervento, presentano problemi respiratori di varia entità; 6 hanno ripreso la loro attività fisica senza nessun sintomo di complicazione respiratorie o ricaduta. I gatti con Ernia Diaframmatica Traumatica possono avere un ottima prognosi se trattatati in maniera appropriata da un punto di vista chirurgico e perioperatorio. SUMMARY The Traumatic Diaphragmatic Hernia is a very hard disease to treat. Purpose of this retrospective study in 21 cats is to determine whether signalment, duration of hernia, clinical signs, contents of hernia, concurrent injuries, perioperative treatment or level of training of veterinarian performing the herniorrhaphy was associated with mortality rate after surgical repair of traumatic diaphragmatic hernia in cats. Medical records of the Department of Clinical Science of University of Pisa, were searched from 2001 through 2006 for cats with diaphragmatic hernia and a long-term follow-up was obtained by a telephone interview with the owner or referring veterinarian or by review of the medical record. Mean age of affected cats was 3 years and 4 months. Domestic short hair cats (85,71%) was the most affected breed. The most common cause of traumatic diaphragmatic hernia in cats was a motor vehicle accidents (8/21) or unknown trauma (10/21). Dyspnea was the most common clinical sign at hospital admission. Seventeen cats were treated with surgical herniorraphy, 3 cats died for intra- or post-operative complications. Long-term follow-up was available for 8 cats that survived diaphragmatic herniorrhaphy. No abnormalities were reported in 6 cats; 2 cats showed dyspnea after strenuous exercise. The cats with Traumatic Daiphragmatic Hernia can have an excellent prognosis with appropriate surgical technique and perioperative care