Entanglement generation in the ultra-strongly coupled Rabi model

We analyze the dynamics of the quantum Rabi model for two qubits interacting through a common bosonic field mode (resonator), focusing on the generation and detection of maximally entangled Bell states. We obtain analytical results for the unitary dynamics of this system in the slow-qubit (or degenerate) regime, considering ultra-strong coupling between qubits and resonator mode, for which the rotating wave approximation is no longer applicable. We also numerically investigate the dynamics beyond the slow-qubit condition in order to study the validity of the model in the presence of less strict conditions.Comment: 11 pages, 6 figures; submitted to the special issue of International Journal of Quantum Information as contribution to the Quantum 2014 conferenc

Whole-metagenome-sequencing-based community profiles of Vitis vinifera L. cv. Corvina berries withered in two post-harvest conditions

Vitis vinifera L. cv. Corvina grape forms the basis for the production of unique wines, such as Amarone, whose distinctive sensory features are strongly linked to the post-harvest grape withering process. Indeed, this process increases sugar concentration and changes must characteristics. While microorganisms involved in must fermentation have been widely investigated, few data are available on the microbiota of withered grapes. Thus, in this paper, a whole metagenome sequencing (WMS) approach was used to analyse the microbial consortium associated with Corvina berries at the end of the withering process performed in two different conditions (“traditional withering,” TW or “accelerated withering,” AW), and to unveil whether changes of drying parameters could have an impact on microbial diversity. Samples of healthy undamaged berries were collected and washed, to recover microorganisms from the surface and avoid contamination with grapevine genetic material. Isolated DNA was sequenced and the data obtained were analyzed with several bioinformatics methods. The eukaryotic community was mainly composed by members of the phylum Ascomycota, including Eurotiomycetes, Sordariomycetes, and Dothideomycetes. Moreover, the distribution of the genera Aspergillus and Penicillium (class Eurotiomycetes) varied between the withered berry samples. Instead, Botryotinia, Saccharomyces, and other wine technologically useful microorganisms were relatively scarce in both samples. For prokaryotes, 25 phyla were identified, nine of which were common to both conditions. Environmental bacteria belonging to the class Gammaproteobacteria were dominant and, in particular, the TW sample was characterized by members of the family Pseudomonadaceae, while members of the family Enterobacteriaceae dominated the AW sample, in addition to Sphyngobacteria and Clostridia. Finally, the binning procedure discovered 15 putative genomes which dominated the microbial community of the two samples, and included representatives of genera Erwinia, Pantoea, Pseudomonas, Clostridium, Paenibacillus, and of orders Lactobacillales and Actinomycetales. These results provide insights into the microbial consortium of Corvina withered berries and reveal relevant variations attributable to post-harvest withering conditions, underling how WMS could open novel perspectives in the knowledge and management of the withering process of Corvina, with an impact on the winemaking of important Italian wines

Long-Term Hemodynamic Performance of the Aortic Valve After David I: An Echocardiographic Study

Despite optimal hemodynamics at rest, the performance of the aortic valve under stress conditions long after David I procedure is still debated. From 2001-2014, 73 patients underwent reimplantation with David I technique. Aortic valve function of 13 patients (age 61.2 ± 8.72) with a follow-up of at least 5 years (6.3 ± 0.9 years) was assessed at exercise echocardiographic stress test on a stationary cycle. Patients who had undergone concomitant procedure, with recurrent aortic insufficiency or mitral valve incompetence, were excluded. In all, 8 healthy volunteers served as controls. Transvalvular gradients progressively increased during the steps in both groups (P-within < 0.001), being higher in David patients (P-between < 0.001), but never reaching a clinical significance (David Peak gradient 23.8 ± 9.3 mmHg; Mean gradient 13.2 ± 5.1 mmHg). Effective orifice area (EOA) and EOA index did not change during the test in David patients, whereas Controls showed a progressive increase of functional valve area to a peak at 50 W (Controls EOA 4.0 ± 0.5 cm(2); EOA index 2.0 ± 0.3 cm(2)/m(2)). In conclusion, David I procedure ensures good hemodynamics during high-flow conditions at long-term follow-up. The reimplantation of the functional aortic annulus inside a rigid tube determines a paradoxical reduction of functional aortic valve area, secondary to the increased stroke volume, without any clinically relevant increase in transvalvular gradients. These data confirm the reliability of David I in the long term, even under physical stress conditions