Classical microscopic theory of dispersion, emission and absorption of light in dielectrics

This paper is a continuation of a recent one in which, apparently for the first time, the existence of polaritons in ionic crystals was proven in a microscopic electrodynamic theory. This was obtained through an explicit computation of the dispersion curves. Here the main further contribution consists in studying electric susceptibility, from which the spectrum can be inferred. We show how susceptibility is obtained by the Green--Kubo methods of Hamiltonian statistical mechanics, and give for it a concrete expression in terms of time--correlation functions. As in the previous paper, here too we work in a completely classical framework, in which the electrodynamic forces acting on the charges are all taken into account, both the retarded forces and the radiation reaction ones. So, in order to apply the methods of statistical mechanics, the system has to be previously reduced to a Hamiltonian one. This is made possible in virtue of two global properties of classical electrodynamics, namely, the Wheeler--Feynman identity and the Ewald resummation properties, the proofs of which were already given for ordered system. The second contribution consists in formulating the theory in a completely general way, so that in principle it applies also to disordered systems such as glasses, or liquids or gases, provided the two general properties mentioned above continue to hold. A first step in this direction is made here by providing a completely general proof of the Wheeler--Feynman identity, which is shown to be the counterpart of a general causality property of classical electrodynamics. Finally it is shown how a line spectrum can appear at all in classical systems, as a counterpart of suitable stability properties of the motions, with a broadening due to a coexistence of chaoticity

On the definition of temperature in FPU systems

It is usually assumed, in classical statistical mechanics, that the temperature should coincide, apart from a suitable constant factor, with the mean kinetic energy of the particles. We show that this is not the case for \FPU systems, in conditions in which energy equipartition between the modes is not attained. We find that the temperature should be rather identified with the mean value of the energy of the low frequency modes.Comment: 12 pages, 4 Figure

FPU phenomenon for generic initial data

The well known FPU phenomenon (lack of attainment of equipartition of the mode--energies at low energies, for some exceptional initial data) suggests that the FPU model does not have the mixing property at low energies. We give numerical indications that this is actually the case. This we show by computing orbits for sets of initial data of full measure, sampled out from the microcanonical ensemble by standard Montecarlo techniques. Mixing is tested by looking at the decay of the autocorrelations of the mode--energies, and it is found that the high--frequency modes have autocorrelations that tend instead to positive values. Indications are given that such a nonmixing property survives in the thermodynamic limit. It is left as an open problem whether mixing obtains within time--scales much longer than the presently available ones

"Le declinazioni dell'io":l'influenza del multilinguismo sull'individualita in The Book of Negroes di Lawrence Hill.

Il presente lavoro analizza come il linguaggio e le lingue, temi centrali per la produzione letteraria post coloniale, possano influire sulla costruzione della personalità di un individuo. Il primo capitolo presenta il panorama letterario canadese dalle origini a oggi e si vedrà come l'autore, Lawrence Hill, e l'opera presa in analisi, The Book of Negroes, si inseriscono all'interno di questo panorama. Il secondo capitolo contiene la traduzione con testo originale a fronte, di una parte del romanzo con una breve analisi delle difficoltà traduttive. La terza analizza come la Bildung della protagonista,sia segnata dall'apprendimento di nuove lingue. A partire da Hegel fino a Gayatri Spivak, Édouard Glissant, Franz Fanon, si analizzerà l'influenza del multilinguismo sull'individialità, quanto i diversi livelli di competenza linguistica influiscano l'identità di un individuo, la percezione che lo stesso ha di sé e quella che terzi hanno di lui e, infine, quanto sia importante, per coloro che vengono chiamati "subalterni", avere una propria voce per poter raccontare la Storia dal loro punto di vista. This work analyses how language and tongues, major themes for the postcolonial literature, have an influence on one character's Bildung. The first chapter presents a panorama of the Canadian literature from the origins until today and how the author, Lawrence Hill, and his work, The Book of Negroes, are part of this panorama. The second chapter consists in a translation of part of the novel and a little analysis of the translation problems. The third part analyses how the Bildung of the major character is influenced by learning new languages. From Hegel to Gayatri Spivak, Édouard Glissant, Franz Fanon, the last chapter analyses the influence of multilingualism on the individuality, how the different levels of linguistic competence affect ones identity, the sense of self that one has, and how the others see him. Last but not least, the importance for the "subalterns" to have their own voice in order to tell the History from their point of view

Aligning With Patient-Centered Medical Home Standards: Depression Screening in Women\u27s Health

Problem: The Patient Centered Medical Home (PCMH) model of care improves health care quality and patient experience of care, and decreases costs. Depression screening is a requirement for becoming a PCMH. The purpose of this quality initiative was to obtain baseline data to describe depression screening rates among female adult patients receiving women’s health care within a Midwestern public health department seeking PCMH recognition. Methods: The study utilized a descriptive, observational design and was guided by the Plan-Do-Study-Act framework. A retrospective medical record review was used to assess the rate of depression screening utilizing the PHQ-2 and PHQ-9 tools, and the rate of treatment. Results: In the pilot study period there were 417 documented visits, and the PHQ-2 depression screening rate was 32.61% (n = 136). The rate for a PHQ-9 was 5.92% (n = 8), and the treatment rate was 2.95% (n = 4). Linear regression analyses found that positive PHQ-2 screenings significantly predicted the occurrence of PHQ-9 screenings (p \u3c .001). Furthermore, positive PHQ-2 and PHQ-9 screenings significantly predicted the rate of treatment (p \u3c .001). Implications for Practice: Findings support the continued use of a validated depression screening tool to identify depression risk or other related mental health risks. Prior to this project, there was no formal depression screening. Women’s health patients were identified for depression risk through screening who may not have otherwise been identified. Through successful implementation of the PHQ-2 and PHQ-9 tools, the public health department is better prepared to achieve PCMH recognition