Quantum test of the equivalence principle for atoms in superpositions of internal energy eigenstates

The Einstein Equivalence Principle (EEP) has a central role in the understanding of gravity and space-time. In its weak form, or Weak Equivalence Principle (WEP), it directly implies equivalence between inertial and gravitational mass. Verifying this principle in a regime where the relevant properties of the test body must be described by quantum theory has profound implications. Here we report on a novel WEP test for atoms. A Bragg atom interferometer in a gravity gradiometer configuration compares the free fall of rubidium atoms prepared in two hyperfine states and in their coherent superposition. The use of the superposition state allows testing genuine quantum aspects of EEP with no classical analogue, which have remained completely unexplored so far. In addition, we measure the Eotvos ratio of atoms in two hyperfine levels with relative uncertainty in the low $10^{-9}$, improving previous results by almost two orders of magnitude.Comment: Accepted for publication in Nature Communicatio

Hygienic and sanitary standards of housing in Europe: a comparative analysis of nine countries

In recent years, growing interest was devoted to housing conditions from both scientific community and public health, so they are now considered among the main environmental and social health determinants of health of the population. Aim of the study is to analyze and compare the current regulations regarding housing sanitary requirements in different Countries of the EU (Sweden, United Kingdom, Denmark, the Netherlands, France, Germany, Portugal, Spain) with the contents of the Italian Health Ministerial Decree 5th July 1975. From the websites of the official channels of the various countries the regulations have been downloaded. For the comparison, only the aspects of BCs concerning the scale of the building were examined; the comparison concerned all the requirements of the Health Ministerial Decree of 5.07.1975 and some other parameters (e.g. indoor chemical pollution, ionizing radiation, non-ionizing radiation) not provided for in the Ministerial Decree, treated in the other standards regulations, and relevant for the indoor well-being of the occupants. The authors observe a wide variability in the contents and in the formulation of the hygienic-sanitary requirements among the different Building Codes, above all as regards the dimensional data and some fundamental themes (e.g. heating systems, mechanical ventilation) whose treatment is often not it is updated with respect to the technological-scientific innovation consolidated over the past few years. A diverse approach among European Countries is also observed: from a market-oriented logic (e.g. UK), to a prescriptive one (Italy), to a functionality-oriented (the Netherlands). The comparative analysis we carried out made it possible to identify convergences and divergences in the standards analysed for the different European countries. As far as the Italian legislation on the usability of residential premises, finally, considering the health, social, environmental and economic trends, many standards contained in the MD 5th July 1975 should be reviewed and updated

The Relationships between Cognitive Styles and Creativity: The Role of Field Dependence-Independence on Visual Creative Production

Previous studies explored the relationships between field dependent-independent cognitive style (FDI) and creativity, providing misleading and unclear results. The present research explored this problematic interplay through the lens of the Geneplore model, employing a product oriented task: the Visual Creative Synthesis Task (VCST). The latter requires creating objects belonging to pre-established categories, starting from triads of visual components and consists of two steps: the preinventive phase and the inventive phase. Following the Amabile’s consensual assessment technique, three independent judges evaluated preinventive structures in terms of originality and synthesis whereas inventions were evaluated in terms of originality and appropriateness. The Embedded Figure Test (EFT) was employed in order to measure the individual’s predisposition toward the field dependence or the field independence. Sixty undergraduate college students (31 females) took part in the experiment. Results revealed that field independent individuals outperformed field dependent ones in each of the four VCST scores, showing higher levels of creativity. Results were discussed in light of the better predisposition of field independent individuals in mental imagery, mental manipulation of abstract objects, as well as in using their knowledge during complex tasks that require creativity. Future research directions were also discussed

A Search for Pulsars in Quiescent Soft X-Ray Transients. I

We have carried out a deep search at 1.4 GHz for radio pulsed emission from six soft X-ray transient sources observed during their X-ray quiescent phase. The commonly accepted model for the formation of the millisecond radio pulsars predicts the presence of a rapidly rotating, weakly magnetized neutron star in the core of these systems. The sudden drop in accretion rate associated with the end of an X-ray outburst causes the Alfv\`en surface to move outside the light cylinder, allowing the pulsar emission process to operate. No pulsed signal was detected from the sources in our sample. We discuss several mechanisms that could hamper the detection and suggest that free-free absorption from material ejected from the system by the pulsar radiation pressure could explain our null result.Comment: accepted by Ap

C4BQ0: a genetic marker of familial HCV-related liver cirrhosis.

Source Department of Medicine and Pneumology, V Cervello Hospital, Via Trabucco 180, 90146 Palermo, Italy. [email protected] Abstract BACKGROUND AND METHODS: Host may have a role in the evolution of chronic HCV liver disease. We performed two cross-sectional prospective studies to evaluate the prevalence of cirrhosis in first degree relatives of patients with cirrhosis and the role of two major histocompatibility complex class III alleles BF and C4 versus HCV as risk factors for familial clustering. FINDINGS: Ninety-three (18.6%) of 500 patients with cirrhosis had at least one cirrhotic first degree relative as compared to 13 (2.6%) of 500 controls, (OR 7.38; CI 4.21-12.9). C4BQ0 was significantly more frequent in the 93 cirrhotic patients than in 93 cirrhotic controls without familiarity (Hardy-Weinberg equilibrium: chi2 5.76, P = 0.016) and in 20 families with versus 20 without aggregation of HCV related cirrhosis (29.2% versus 11.3%, P = 0.001); the association C4BQ0-HCV was found almost only in cirrhotic patients with a family history of liver cirrhosis. CONCLUSIONS: Our studies support the value of C4BQ0 as a risk indicator of familial HCV related cirrhosis

Competing risks and prognostic stages of cirrhosis: A 25-year inception cohort study of 494 patients

Background Morphological, haemodynamic and clinical stages of cirrhosis have been proposed, although no definite staging system is yet accepted for clinical practice. Aim To investigate whether clinical complications of cirrhosis may define different prognostic disease stages. Methods Analysis of the database from a prospective inception cohort of 494 patients. Decompensation was defined by ascites, bleeding, jaundice or encephalopathy. Explored potential prognostic stages: 1, compensated cirrhosis without oesophago-gastric varices; 2, compensated cirrhosis with varices; 3, bleeding without other complications; 4, first nonbleeding decompensation; 5, any second decompensating event. Patient flow across stages was assessed by a competing risks analysis. Results Major patient characteristics were: 199 females, 295 males, 404 HCV+, 377 compensated, 117 decompensated cirrhosis. The mean follow-up was 145 ± 109 months without dropouts. Major events: 380 deaths, 326 oesophago-gastric varices, 283 ascites, 158 bleeding, 146 encephalopathy, 113 jaundice, 126 hepatocellular carcinoma and 19 liver transplantation. Patients entering each prognostic stage along the disease course were: 202, stage 1; 216, stage 2; 75 stage 3; 206 stage 4; 213 stage 5. Five-year transition rate towards a different stage, for stages 1-4 was 34.5%, 42%, 65% and 78%, respectively (P < 0.0001); 5-year mortality for stages 1-5 was 1.5%, 10%, 20%, 30% and 88% respectively (P < 0.0001). An exploratory analysis showed that this patient stratification may configure a prognostic system independent of the Child-Pugh score, Model for End Stage Liver Disease and comorbidity. Conclusion The development of oesophago-gastric varices and decompensating events in cirrhosis identify five prognostic stages with significantly increasing mortality risks

Spin-based optical quantum gates via Pauli blocking in semiconductor quantum dots

We present a solid-state implementation of ultrafast conditional quantum gates. Our proposal for a quantum-computing device is based on the spin degrees of freedom of electrons confined in semiconductor quantum dots, thus benefiting from relatively long decoherence times. More specifically, combining Pauli blocking effects with properly tailored ultrafast laser pulses, we are able to obtain sub-picosecond spin-dependent switching of the Coulomb interaction, which is the essence of our conditional phase-gate proposal. This allows us to realize {\it a fast two qubit gate which does not translate into fast decoherence times} and paves the road for an all-optical spin-based quantum computer.Comment: 14 Pages RevTeX, 3 eps figures include

Importance of Spin-Orbit Interaction for the Electron Spin Relaxation in Organic Semiconductors

Despite the great interest organic spintronics has recently attracted, there is only a partial understanding of the fundamental physics behind electron spin relaxation in organic semiconductors. Mechanisms based on hyperfine interaction have been demonstrated, but the role of the spin-orbit interaction remains elusive. Here, we report muon spin spectroscopy and time-resolved photoluminescence measurements on two series of molecular semiconductors in which the strength of the spin-orbit interaction has been systematically modified with a targeted chemical substitution of different atoms at a particular molecular site. We find that the spin-orbit interaction is a significant source of electron spin relaxation in these materials