Transfer of coherence from atoms to mixed field states in a two-photon lossless micromaser

We propose a two-photon micromaser-based scheme for the generation of a nonclassical state from a mixed state. We conclude that a faster, as well as a higher degree of field purity is achieved in comparison to one-photon processes. We investigate the statistical properties of the resulting field states, for initial thermal and (phase-diffused) coherent states. Quasiprobabilities are employed to characterize the state of the generated fields.Comment: 20 pages, 8 figures, to appear in Journal of Modern Optic

The Redevelopment of The Heritage of Social Housing in Italy: Survey and Assessment Instruments. The Case Study of Pilastro Neighborhood in Bologna

Abstract The increasing importance of social housing in order to deal with the emergency caused by the pressing demand, places in the foreground the need to redevelop the existing public housing heritage. The paper proposes the deepening of one case study, the Pilastro neighborhood, a significant example of social housing high density settlement, situated in the outskirts of Bologna in order to brought out the technical, functional and social factors, on which the level of quality of the settlement and the phenomena of social uneasiness depend. It also highlighted some factors that may pose a resistance to the measures of improvement

Unitary transformation approach for the trapped ion dynamics

We present a way of treating the problem of the interaction of a single trapped ion with laser beams based on successive aplications of unitary transformations onto the Hamiltonian. This allows the diagonalization of the Hamiltonian, by means of recursive relations, without performing the Lamb-Dicke approximation.Comment: 8 page

Spontaneous emission and teleportation in cavity QED

In this work, we consider atomic spontaneous emission in a system consisting of two identical two-level atoms interacting dispersively with the quantized electromagnetic field in a high-Q cavity. We investigate the destructive effect of the atomic decay on the generation of maximally entangled states, following the proposal by Zheng S B and Guo G C (2000 Phys. Rev. Lett. 85 2392). In particular, we analyze the fidelity of teleportation performed using such a noisy channel and calculatethe maximum spontaneous decay rate we may have in order to realize teleportation.Comment: 11 pages, 6 figures, LaTe

Quantum state engineering via unitary transformations

We construct a Hamiltonian for the generation of arbitrary pure states of the quantized electromagnetic field. The proposition is based upon the fact that a unitary transformation for the generation of number states has been already found. The general unitary transformation here obtained, would allow the use of nonlinear interactions for the production of pure states. We discuss the applicability of this method by giving examples of generation of simple superposition states. We also compare our Hamiltonian with the one resulting from the interaction of trapped ions with two laser fields.Comment: 5 pages in RevTeX, no figures, accepted for publication in Phys. Rev.

Temporal changes in blood-brain barrier permeability and cerebral perfusion in lacunar/subcortical ischemic stroke

BACKGROUND: Cerebral microvascular abnormality is frequently associated with lacunar and subcortical ischemic lesions. We performed acute and follow-up CT perfusion scans over the first 3 months after ischemic stroke to investigate disturbances of the blood–brain barrier (BBB) and cerebral perfusion in patients with lacunar/subcortical lesions compared to those with cortical lesions alone. METHODS: Thirty-one patients with lacunar/subcortical infarct (n = 14) or with cortical large vessel infarct (n = 17) were recruited and underwent a CT perfusion study at admission, 24 h, 7 days and 3 months after stroke using a two-phase imaging protocol. Functional maps of BBB permeability surface area product (BBB-PS), cerebral blood flow (CBF) and blood volume (CBV) at follow-up were co-registered with those at admission, and the measurements in non-infarcted ipsilateral basal ganglia and thalamus were compared within each group and between the two groups. RESULTS: For the lacunar/subcortical group, BBB-PS within non-infarcted ipsilateral basal ganglia and thalamus peaked at day 7 compared to all other time points, and was significantly higher than the cortical group at day 7 and month 3. The CBF and CBV in the same region were significantly lower at admission and transient hyperemia was seen at day 7 in the lacunar/subcortical group. CONCLUSION: Disturbed BBB-PS and compromised cerebral perfusion over the first 3 months post stroke were shown in the non-infarcted basal ganglia and thalamus of lacunar/subcortical stroke using CT perfusion. Future studies are required to elucidate the relationship of post-stroke BBB disturbances to chronic cognitive impairment

PICKING THE BEST NOVEL ORAL ANTICOAGULANT FOR ATRIAL FIBRILLATION: EVIDENCE FROM A WARFARIN-CONTROLLED NETWORK META-ANALYSIS

Warfarin is a mainstay atrial ibrillation (AF) treatment, yet it has a narrow therapeutic window. Novel agents have been successfully tested against warfarin, yet no direct comparison among them is available. We thus performed a pair-wise and warfarin-adjusted network metaanalyses of novel oral anticoagulants for AF

Monitoring of Communication Precursors in Extremely Low Birth Weight (ELBW) Newborns by Video Analysis Method: Preliminary Results

Background: The survival of extremely low birth weight infants (ELBW) has increased worldwide. Even in the absence of major disabilities, ELBW infants show difficulty in simple language functions. It is relevant to assess early abilities, which are the base of early linguistic skills, in order to implement customized intervention programs in ELBW infants. Aims: To evaluate communication precursors of language development in ELBW infants at 12 and 24 months of correct age (C.A). To investigate the correlation of linguistic and communicative prerequisites with mental development outcome at 24 months CA. Method: 52 ELBW neonates (mean gestational age 26.6 weeks, mean birth weight was 775 g) who were admitted to the neonatal intensive care unit of the University Hospital of Modena, were enrolled. Data were collected from archived audio-video recordings of neurodevelopmental follow-up visits. Video analysis of communicative and linguistic developmental was performed at 12 and 24 months CA. Neurodevelopmental outcome was evaluated with Mental Developmental Scales (GMDS-R). Results: The video-analysis showed that infants at 12 months CA used predominantly eye contacts and gestural turns, while vocal turns were scant. At 24 months CA, a significant change in eye contacts, vocal turns, gestural turns, and utterances (p < 0.001) occurred. The total number of utterances (p = 0.036) and eye contacts (p = 0.045) were significantly correlated to the Development Quotient (DQ) of Hearing and Language scale. Moreover, a significant correlation was found with the Personal-Social scale vocal turns (p = 0.009) and the total number of utterances (p = 0,02). Finally, the Global Quotient of the GMDS-R was related to the Vocal Turns (p = 0.034) and the total number of Utterances (p = 0.013). Conclusions: ELBW infants at 12 months CA use predominantly eye contacts and gestural turns to communicate with adults. At 24 months CA, the child’s communicative intention evolves from gestural to verbal communication. The latter is characterized by an increase in both vocal turns and the number of utterances produced during interaction. The video analysis we implement appears to be a sensitive tool for early assessment of communication and language development and to refine early intervention