Dynamics of a particle confined in a two-dimensional dilating and deforming domain

Some recent results concerning a particle confined in a one-dimensional box with moving walls are briefly reviewed. By exploiting the same techniques used for the 1D problem, we investigate the behavior of a quantum particle confined in a two-dimensional box (a 2D billiard) whose walls are moving, by recasting the relevant mathematical problem with moving boundaries in the form of a problem with fixed boundaries and time-dependent Hamiltonian. Changes of the shape of the box are shown to be important, as it clearly emerges from the comparison between the "pantographic", case (same shape of the box through all the process) and the case with deformation.Comment: 13 pages, 2 figure

Tripartite thermal correlations in an inhomogeneous spin-star system

We exploit the tripartite negativity to study the thermal correlations in a tripartite system, that is the three outer spins interacting with the central one in a spin-star system. We analyze the dependence of such correlations on the homogeneity of the interactions, starting from the case where central-outer spin interactions are identical and then focusing on the case where the three coupling constants are different. We single out some important differences between the negativity and the concurrence.Comment: 8 pages, 9 figure

Quantifying within-group variation in sociality—covariation among metrics and patterns across primate groups and species

It has long been recognized that the patterning of social interactions within a group can give rise to a social structure that holds very different places for different individuals. Such within-group variation in sociality correlates with fitness proxies in fish, birds, and mammals. Broader integration of this research has been hampered by the lack of agreement on how to integrate information from a plethora of dyadic interactions into individual-level metrics. As a step towards standardization, we collected comparative data on affinitive and affiliative interactions from multiple groups each of five species of primates to assess whether the same aspects of sociality are measured by different metrics and indices. We calculated 16 different sociality metrics used in previous research and thought to represent three different sociality concepts. We assessed covariation of metrics within groups and then summarized covariation patterns across all 15 study groups, which varied in size from 5 to 41 adults. With some methodological and conceptual caveats, we found that the number of weak ties individuals formed within their groups represented a dimension of sociality that was largely independent from the overall number of ties as well as from the number and strength of the strong ties they formed. Metrics quantifying indirect connectedness exhibited strong covariation with strong tie metrics and thus failed to capture a third aspect of sociality. Future research linking affiliation and affinity to fitness or other individual level outcomes should quantify inter-individual variation in three aspects: the overall number of ties, the number of weak ties, and the number or strength of strong ties individuals form, after taking into account effects of social network density. Significance statement: In recent years, long-term studies of individually known animals have revealed strong correlations between individual social bonds and social integration, on the one hand, and reproductive success and survival on the other hand, suggesting strong natural selection on affiliative and affinitive behavior within groups. It proved difficult to generalize from these studies because they all measured sociality in slightly different ways. Analyzing covariation between 16 previously used metrics identified only three rather independent dimensions of variation. Thus, different studies have tapped into the same biological phenomenon. How individuals are weakly connected within their group needs further attention.Peer Reviewe

Information-theoretic equilibrium and observable thermalization

A crucial point in statistical mechanics is the definition of the notion of thermal equilibrium, which can be given as the state that maximises the von Neumann entropy, under the validity of some constraints. Arguing that such a notion can never be experimentally probed, in this paper we propose a new notion of thermal equilibrium, focused on observables rather than on the full state of the quantum system. We characterise such notion of thermal equilibrium for an arbitrary observable via the maximisation of its Shannon entropy and we bring to light the thermal properties that it heralds. The relation with Gibbs ensembles is studied and understood. We apply such a notion of equilibrium to a closed quantum system and show that there is always a class of observables which exhibits thermal equilibrium properties and we give a recipe to explicitly construct them. Eventually, an intimate connection with the Eigenstate Thermalisation Hypothesis is brought to light

Hyperthermic antiblastic perfusion in the treatment of stage IIIA-IIIAB melanoma patients. Comparison of two experiences.

Many reports have been published concerning the efficacy of hyperthermic antiblastic perfusion (HAP) for the treatment of recurrent limb melanoma. In terms of tumour response, loco-regional control and survival, the results vary greatly even in patients with the same disease stage treated with the same technique. The aim of the present report was therefore to compare the experiences of two institutes, the Regina Elena National Cancer Institute of Rome and the National Tumour Institute of Milan, in treating a total of 327 patients with stage IIIA and IIIAB melanoma with HAP. The study also examined whether, and to what extent some prognostic factors influence the course of the disease. The tumour temperature proved to be the most important parameter for obtaining a complete tumour response which, in turn, positively affected survival. A direct relationship was found between the rates of complete tumour response and the clinical status of the patients. The complete response rates obtained in patients with no evidence of disease were 62.5% at the Rome institute and 70.1% at the Milan institute as opposed to 23.6% and 39%, respectively, in patients who died of the disease

Local hyperthermia and systemic chemotherapy for treatment of recurrent melanoma.

Thirty-two patients with recurrent (skin) or metastatic (skin, node, or both) melanoma have been treated with a hyperthermia-cisplatin regimen. The hyperthermic treatment was carried out for 60 minutes at 43 degrees C with the MHS-SMA and the Sapic SVO3 ALENIA devices once a week. When the tumor temperature reached 42 degrees C, cisplatin was administered at a dosage of 50 mg/m2 given by intravenous bolus infusion. The treatment was repeated four times and the tumor response evaluated 4 weeks after the last treatment. Significant systemic or local toxicity was not seen. In terms of results, there were 9 patients with complete responses (28.1%), 13 with partial responses (40.6%), 8 with no change (25.0%), and two with disease progression (6.3%). The objective response rate was 68.7%. The response duration for those with complete responses ranged from 4 to 49 months (median 20 months). The median time to progression for patients with partial responses and those with no change was 6 and 5 months, respectively, with ranges of 1-7 and 1-10 months, respectively. The 4-year actuarial survival rates were 47.6% and 20.3% for the complete and incomplete responders, respectively. These results can be considered satisfactory, taking into account that most patients were pretreated with radiotherapy, chemotherapy or both, confirming the therapeutic potential of the hyperthermia and cisplatin regimen