Broken Ergodicity in classically chaotic spin systems

A one dimensional classically chaotic spin chain with asymmetric coupling and two different inter-spin interactions, nearest neighbors and all-to-all, has been considered. Depending on the interaction range, dynamical properties, as ergodicity and chaoticity are strongly different. Indeed, even in presence of chaoticity, the model displays a lack of ergodicity only in presence of all to all interaction and below an energy threshold, that persists in the thermodynamical limit. Energy threshold can be found analytically and results can be generalized for a generic XY model with asymmetric coupling.Comment: 6 pages, 3 figure

IL COLLEGIO SINDACALE NELLE BANCHE

This thesis is aimed at outlining the role of the Board of the Statutory Auditors (the so called \u201cCollegio Sindacale\u201d) in the Italian banks. Specifically, the statutory auditors perform a control that has conventionally been considered to be ex-post and periodic, normally a spot check, for the purpose of informing the shareholders of illegal acts, misconduct, or negligence by the directors. Instead, the monitoring of the Board of Statutory Auditors in the banks seems to assume different connotations in relation to the control assigned to it in "ordinary" companies, as it can be classified as a sort of supervisor of the overall system of internal controls: such monitoring can be implemented not so much subsequently and in a context of sanctions in relation to management irregularities, but more in a preventive context of continuous cooperation with the directors in the correction of organizational structures. Moreover, the goal of the last chapter of the thesis is to analyze if the Board of Statutory Auditors can perform an \u201cex-ante\u201d control also in the ordinary companies, taking into account the need of protection of the minority shareholders, the creditors and the stakeholders

Seeded x-ray free-electron laser generating radiation with laser statistical properties

The invention of optical lasers led to a revolution in the field of optics and even to the creation of completely new fields of research such as quantum optics. The reason was their unique statistical and coherence properties. The newly emerging, short-wavelength free-electron lasers (FELs) are sources of very bright coherent extreme-ultraviolet (XUV) and x-ray radiation with pulse durations on the order of femtoseconds, and are presently considered to be laser sources at these energies. Most existing FELs are highly spatially coherent but in spite of their name, they behave statistically as chaotic sources. Here, we demonstrate experimentally, by combining Hanbury Brown and Twiss (HBT) interferometry with spectral measurements that the seeded XUV FERMI FEL-2 source does indeed behave statistically as a laser. The first steps have been taken towards exploiting the first-order coherence of FELs, and the present work opens the way to quantum optics experiments that strongly rely on high-order statistical properties of the radiation.Comment: 24 pages, 10 figures, 37 reference

Evidence of vectorial photoelectric effect on Copper

Quantum Efficiency (QE) measurements of single photon photoemission from a Cu(111) single crystal and a Cu polycrystal photocathodes, irradiated by 150 fs-6.28 eV laser pulses, are reported over a broad range of incidence angle, both in s and p polarizations. The maximum QE (\simeq 4\times10^{-4}) for polycrystalline Cu is obtained in p polarization at an angle of incidence {\theta} = 65deg. We observe a QE enhancement in p polarization which can not be explained in terms of optical absorption, a phenomenon known as vectorial photoelectric effect. Issues concerning surface roughness and symmetry considerations are addressed. An explanation in terms of non local conductivity tensor is proposed.Comment: 3 pages, 3 figure

Short-wavelength four wave mixing experiments using single and two-color schemes at FERMI

The development of ultra-bright extreme ultraviolet (EUV) and X-ray free electron laser (FEL) sources has enabled the extension of wave-mixing approaches into the short wavelength regime. Such a class of experiments relies upon nonlinear interactions among multiple light pulses offering a unique tool for exploring the dynamics of ultrafast processes and correlations between selected excitations at relevant length and time scales adding elemental and site selectivity as well. Besides the availability of a suitable photon source, the implementation of wave mixing methodology requires efforts in developing the instrumental set-up. We have realized at the FERMI FEL two dedicated set-ups to handle multiple FEL beams with preselected parameters in a non-collinear fashion and control their interaction sequence at the target. These unique apparatuses, combined with the exceptional characteristics of the seeded FERMI FEL, have allowed us to make the first steps into this field and further advances are foreseen in the near future

2015 ACVIM Small Animal Consensus Statement on Seizure Management in Dogs

This report represents a scientific and working clinical consensus statement on seizure management in dogs based on current literature and clinical expertise. The goal was to establish guidelines for a predetermined, concise, and logical sequential approach to chronic seizure management starting with seizure identification and diagnosis (not included in this report), reviewing decision‐making, treatment strategies, focusing on issues related to chronic antiepileptic drug treatment response and monitoring, and guidelines to enhance patient response and quality of life. Ultimately, we hope to provide a foundation for ongoing and future clinical epilepsy research in veterinary medicine

Transient magnetic gratings on the nanometer scale

Laser-driven non-local electron dynamics in ultrathin magnetic samples on a sub-10 nm length scale is a key process in ultrafast magnetism. However, the experimental access has been challenging due to the nanoscopic and femtosecond nature of such transport processes. Here, we present a scattering-based experiment relying on a laser-induced electro- and magneto-optical grating in a Co/Pd ferromagnetic multilayer as a new technique to investigate non-local magnetization dynamics on nanometer length and femtosecond timescales. We induce a spatially modulated excitation pattern using tailored Al near-field masks with varying periodicities on a nanometer length scale and measure the first four diffraction orders in an x-ray scattering experiment with magnetic circular dichroism contrast at the free-electron laser facility FERMI, Trieste. The design of the periodic excitation mask leads to a strongly enhanced and characteristic transient scattering response allowing for sub-wavelength in-plane sensitivity for magnetic structures. In conjunction with scattering simulations, the experiment allows us to infer that a potential ultrafast lateral expansion of the initially excited regions of the magnetic film mediated by hot-electron transport and spin transport remains confined to below three nanometers

TRANSPORTE INTRA-HOSPITALAR DO PACIENTE CRÍTICO

The medicine knowledge and development of new technologies for diagnoses and treatment of patients had permitted the longevity of healthy people and of those with acute or chronic illness. These technological advances are not well distributed, but there are clearly improvements on the management of patients in medical field leading to a lower mortality and a better quality of life. With these improvements, hospitals needed to increase the area of critical care settings. Patients have being beneficiated by these diagnose technologies, most of them including image, but to access them, they need to be transported out of a intensive care unit, needing to maintain the same level of monitorization. That is the great importance on transportation of a critical patient, and it has being neglected by most health professionals. The objective of this article is to make a reflection of the various moments, phases and care involving the intra-hospital transport, discussing its various aspects.O avanço do conhecimento médico e o desenvolvimento da tecnologia para diagnóstico e tratamento das doenças que afligem os seres humanos têm permitido um aumento da longevidade das pessoas hígidas e daquelas que possuem agravos agudos ou crônicos. Embora estes avanços estejam heterogeneamente distribuídos, há uma nítida melhora das condições de atendimento médico em nosso meio e isto tem feito com que pacientes que anteriormente evoluíssem para o óbito, tenham condições de se manterem vivos em diferentes condições de qualidade de vida. Isto tem feito com que os hospitais tenham que aumentar as áreas de atendimento e cuidados de pacientes críticos. Estes pacientes têm sido beneficiados pela tecnologia de diagnóstico, principalmente, de imagem existente e, quase sempre, para ter acesso a estes benefícios, estes pacientes precisam ser transportados para fora da área de cuidados intensivos e manter o mesmo nível de monitorização para que não haja problemas. É aí que está a grande importância do transporte do paciente crítico que, no geral, vem sendo muito negligenciada pelos profissionais de saúde. O objetivo deste artigo é fazer uma reflexão dos vários momentos, fases e cuidados envolvidos no transporte intra-hospitalar, discutindo as suas diversas modalidades

Evidence of extreme domain wall speeds under ultrafast optical excitation

Time-resolved ultrafast EUV magnetic scattering was used to test a recent prediction of >10 km/s domain wall speeds by optically exciting a magnetic sample with a nanoscale labyrinthine domain pattern. Ultrafast distortion of the diffraction pattern was observed at markedly different timescales compared to the magnetization quenching. The diffraction pattern distortion shows a threshold-dependence with laser fluence, not seen for magnetization quenching, consistent with a picture of domain wall motion with pinning sites. Supported by simulations, we show that a speed of $\approx$ 66 km/s for highly curved domain walls can explain the experimental data. While our data agree with the prediction of extreme, non-equilibrium wall speeds locally, it differs from the details of the theory, suggesting that additional mechanisms are required to fully understand these effects.Comment: 5 pages, 4 figures; Supplemental Material: 8 pages, 9 figure

Nanoscale transient magnetization gratings excited and probed by femtosecond extreme ultraviolet pulses

We utilize coherent femtosecond extreme ultraviolet (EUV) pulses derived from a free electron laser (FEL) to generate transient periodic magnetization patterns with periods as short as 44 nm. Combining spatially periodic excitation with resonant probing at the dichroic M-edge of cobalt allows us to create and probe transient gratings of electronic and magnetic excitations in a CoGd alloy. In a demagnetized sample, we observe an electronic excitation with 50 fs rise time close to the FEL pulse duration and ~0.5 ps decay time within the range for the electron-phonon relaxation in metals. When the experiment is performed on a sample magnetized to saturation in an external field, we observe a magnetization grating, which appears on a sub-picosecond time scale as the sample is demagnetized at the maxima of the EUV intensity and then decays on the time scale of tens of picoseconds via thermal diffusion. The described approach opens prospects for studying dynamics of ultrafast magnetic phenomena on nanometer length scales