Notes pour une mise au point:Peintres et photographes italiens de la deuxi\ue8me moiti\ue9 du XIXesi\ue8cle

Catalogo della mostra, Collezioni d'arte e fotografia artistica nell'Italia del Risorgimento, Roma, Museo del Vittoriano-Grenoble, Istituto italiano di cultura. Lo scritto rievoca l'ambivalenza del rapporto tra gli artisti, i pittori, in particolare, e la fotografia nella seconda met\ue0 dell'Ottocento, incerti se accoglierla come un alleato, un utile strumento per la creazione, o un pericoloso rivale

Dynamics of Enceladus and Dione inside the 2:1 Mean-Motion Resonance under Tidal Dissipation

In a previous work (Callegari and Yokoyama 2007, Celest. Mech. Dyn. Astr. vol. 98), the main features of the motion of the pair Enceladus-Dione were analyzed in the frozen regime, i.e., without considering the tidal evolution. Here, the results of a great deal of numerical simulations of a pair of satellites similar to Enceladus and Dione crossing the 2:1 mean-motion resonance are shown. The resonance crossing is modeled with a linear tidal theory, considering a two-degrees-of-freedom model written in the framework of the general three-body planar problem. The main regimes of motion of the system during the passage through resonance are studied in detail. We discuss our results comparing them with classical scenarios of tidal evolution of the system. We show new scenarios of evolution of the Enceladus-Dione system through resonance not shown in previous approaches of the problem.Comment: 36 pages, 12 figures. Accepted in Celestial Mechanics and Dynamical Astronom

"Spin-Disentangled" Exact Diagonalization of Repulsive Hubbard Systems: Superconducting Pair Propagation

By a novel exact diagonalization technique we show that bound pairs propagate between repulsive Hubbard clusters in a superconducting fashion. The size of the matrices that must be handled depends on the number of fermion configurations {\em per spin}, which is of the order of the square root of the overall size of the Hilbert space. We use CuO$_{4}$ units connected by weak O-O links to model interplanar coupling and c-axis superconductivity in Cuprates. The numerical evidence on Cu$_{2}$O$_{8}$ and Cu$_{3}$O$_{12}$ prompts a new analytic scheme describing the propagation of bound pairs and also the superconducting flux quantization in a 3-d geometry.Comment: 5 pages, 3 figure

Hylotrupes bajulus (L.) (Col., Cerambycidae): nutrition and attacked material

Hylotrupes bajulus, attacks softwood utilising the cellulose contained in wood walls as food. The fibre is digested in variable percentages, depending on the type of analysis, 20 to 48% and, according to some authors, without the assistance of intestinal symbiotic microorganisms. Furthermore, there is published work referring to Hylotrupes, concluding that "starch” … “plays no role in the nutrition of the larvae". Nevertheless, considering that attacks of this species decrease with wood seasoning increasing and having been demonstrated, and that “lignin degradation products of spruce wood do not influence larvae development”, it is possible to suppose that cell walls alone are not sufficient to feed this wood boring species. Furthermore, Hylotrupes larvae have chisel shaped mandibles, similar to those of powder post beetle larvae that feed on starch and need to pulverise the wood to access the cellular content. Preliminary research suggests an utilization of wood fibre as well as of starch by larvae of H. bajulus. Therefore, the purpose of this research is to test the degree of digestion of wood fibre from different sources (sapwood or heartwood) and the possible role of symbiotic microorganisms. Larvae of H. bajulus were grown on synthetic diets made of purified wood fibre and/or starch as main components supplied with mineral and vitamin. Substrates and frass were analysed for fibre fractions, starch and acid insoluble ash, the latter used as an indigestible marker. Larvae purified DNA was analysed by means of metagenomics approaches carried out by direct retrieval and analysis of 16S rRNA gene sequences free of cultural bias in order to discover the bacterial diversity from larva alimentary channel alone. Larvae of H. bajulus seem be able to digest either fibre or starch, and a role for symbiotic bacteria is supposed. Keywords: Cellulose, Starch, Frass, Mouth apparatus, Mandibl

Predictors of mortality in patients with Eisenmenger syndrome and admission to the lung transplantation waiting list

Background. Patients with Eisenmenger Syndrome (ES) have very severe irreversible pulmonary hypertension but the criteria for admitting such patients to a lung transplantation waiting list (LTWL) is not clear. Indeed it has been demonstrated that the natural survival of patients with ES is better than the survival achieved through lung transplantation: it follows that no guidelines are available for these patients' admission to an LTWL. The aim of our study was to identify possible predictors of mortality in ES patients in order to reserve admission to the LTWL solely for those patients who would otherwise have the lowest probability of survival. Methods. Since 1991, 57 patients with ES from our rehabilitative centre were admitted to the LTWL of the Division of Cardiac Surgery at San Matteo Hospital, University of Pavia. At the time of the retrospective analysis, patients were divided into a group of non-transplanted survivors (27 patients - 47% of the total) and a group who had died prior to transplantation (16 patients - 28% of the total). The 14 transplanted patients (25% of the total) were not considered in the statistical analysis, considering transplantation as an "external event". Unpaired t tests were used to compare the following factors in the survivors and in those who died: sex, "complexity" of the congenital heart disease underlying the ES, previous cardiac surgery, arterial blood gases, pulmonary function and hemodynamic parameters. Moreover, a stepwise discriminant analysis was performed in order to define a possible set of prognostic factors. Results. PaCO2 was higher in those who subsequently died (36.15±7.42 mmHg) compared with those who survived (32.5±5.33 mmHg), although this difference did not reach a statistical significance (p=0.08). Discriminant analysis defined a model in which a) complexity of the congenital heart disease, b) sex (male) and c) cardiac output were predictive of a higher risk of mortality. Conclusions. This new knowledge can be used in the decision of admission to LTWL in ES patients

The Response of Test Masses to Gravitational Waves in the Coordinates of a Local Observer

The response of laser interferometers to gravitational waves has been calculated in a number of different ways, particularly in the transverse-traceless and the local Lorentz gauges. At first sight, it would appear that these calculations lead to different results when the separation between the test masses becomes comparable to the wavelength of the gravitational wave. In this paper this discrepancy is resolved. We describe the response of free test masses to plane gravitational waves in the coordinate frame of a local observer and show that it acquires contributions from three different effects: the displacement of the test masses, the apparent change in the photon velocity, and the variation in the clock speed of the local observer, all of which are induced by the gravitational wave. Only when taken together do these three effects represent a quantity which is translationally invariant. This translationally-invariant quantity is identical to the response function calculated in the transverse-traceless gauge. We thus resolve the well-known discrepancy between the two coordinates systems, and show that the results found in the coordinate frame of a local observer are valid for large separation between the masses.Comment: 25 pages, 3 figures, Latex2

Wave packet dynamics of potassium dimers attached to helium nanodroplets

The dynamics of vibrational wave packets excited in K$_2$ dimers attached to superfluid helium nanodroplets is investigated by means of femtosecond pump-probe spectroscopy. The employed resonant three-photon-ionization scheme is studied in a wide wavelength range and different pathways leading to K$^+_2$-formation are identified. While the wave packet dynamics of the electronic ground state is not influenced by the helium environment, perturbations of the electronically excited states are observed. The latter reveal a strong time dependence on the timescale 3-8 ps which directly reflects the dynamics of desorption of K$_2$ off the helium droplets

Cathode Active Material Recycling from Spent Lithium Batteries: A Green (Circular) Approach Based on Deep Eutectic Solvents

The transition to a circular economy vision must handle the increasing request of metals required to satisfy the battery industry; this can be obtained by recycling and feeding back secondary raw materials recovered through proper waste management. Here, a novel and green proof-of-concept was developed, based on deep eutectic solvents (DESs) to fully and easily recover valuable metals from various cathode active materials, including LiMn2O4, LiNi0.5Mn1.5O4, and LiNi0.8Co0.2O2. DES composed of choline chloride and lactic acid could leach Li, Mn, Co, and Ni, achieving efficiency of 100 % under much milder conditions with respect to the previous literature. For the first time, to our best knowledge, a two-step approach was reported in the case of LiNi0.8Co0.2O2 for selective recovery of Li, Co, and Ni with high yield and purity. Furthermore, other cathode components, namely aluminum current collector and binder, were found to be not dissolved by the proposed DES, thus making a simple separation from the active material possible. Finally, this strategy was designed to easily regenerate and reuse the leaching solvents for more than one extraction, thus further boosting process sustainability