Magnetic imaging of pearl vortices in artificially layered (Ba 0.9Nd0.1CuO2+x)m/(CaCuO 2)n systems

We have used scanning SQUID magnetometry to image vortices in ultrathin (Ba0.9Nd0.1CuO2+x)(m)/(CaCuO2)(n) high temperature superconductor samples, with as few as three superconducting CuO2 planes. The Pearl lengths (Lambda=2lambda(L)(2)/d, lambda(L) the London penetration depth, d the superconducting film thickness) in these samples, as determined by fits to the vortex images, agree with those by local susceptibility measurements, and can be as long as 1 mm. The in-plane penetration depths lambda(ab) inferred from the Pearl lengths are longer than many bulk cuprates with comparable critical temperatures. We speculate on the causes of the long penetration depths, and on the possibility of exploiting the unique properties of these superconductors for basic experiments

Low noise cryogenic system for the measurement of Casimir energy in rigid cavities

We report on preliminary results on the measurement of variations of the Casimir energy in rigid cavities through its influence on the superconducting transition of in-cavity aluminium (Al) thin films. After a description of the experimental apparatus we report on a measurement made with thermal photons, discussing its implications for the zero-point photons case. Finally we show the preliminary results for the zero-point case.Comment: 9 pages, 7 figures, Talk given at QFEXT07 Conference in Liepzig: Quantum Field Theory Under the Influence of External Condition

Dissipation in ultra-thin current-carrying superconducting bridges; evidence for quantum tunneling of Pearl vortices

We have made current-voltage (IV) measurements of artificially layered high-$T_c$ thin-film bridges. Scanning SQUID microscopy of these films provides values for the Pearl lengths $\Lambda$ that exceed the bridge width, and shows that the current distributions are uniform across the bridges. At high temperatures and high currents the voltages follow the power law $V \propto I^n$, with $n=\Phi_0^2/8\pi^2\Lambda k_B T+1$, and at high temperatures and low-currents the resistance is exponential in temperature, in good agreement with the predictions for thermally activated vortex motion. At low temperatures, the IV's are better fit by $\ln V$ linear in $I^{-2}$. This is expected if the low temperature dissipation is dominated by quantum tunneling of Pearl vortices.Comment: 5 pages, 7 fig

The Aladin2 experiment: status and perspectives

Aladin2 is an experiment devoted to the first measurement of variations of Casimir energy in a rigid cavity. The main scientific motivation relies on the possibility of the first demonstration of a phase transition influenced by vacuum fluctuations. The guiding principle of the measurement, based on the behaviour of the critical field for an in-cavity superconducting film, will be only briefly recalled. In this paper, after an introduction to the long term motivations, the experimental apparatus and the results of the first measurement of sensitivity will be presented in detail, particularly in comparison with the expected signal. Last, the most important steps towards the final measurement will be discussed.Comment: Talk given by Calloni at QFEXT05 Conference in Barcelona: Quantum Field Theory Under the Influence of External Condition

Clinical Evaluation and Orodental Status in a Group of Elderly Institutionalised Patients

10% of elderly patients are functionally dependents and they therefore need permanent assistance. Orodental alterations may evolve into a pathological state in elderly people, which is increasing in the recent decades. The current study analysed institutionalized patients in the district of Bari (Southern Italy), who have been so far monitored. We assessed 125 elderly institutionalized patients. The assessment has been carried out by an assessment questionnaire aiming at evaluating the patient’s psychophysical health status, objective intraoral test and prosthetic rehabilitations. About 90% of enrolled patients reported a good general health status. The main dental problems are due to the complete lack of specific prevention and treatment programs, together with handicap, presence of systemic diseases and medicines taken. The level of oral hygiene is poor and the conditions of the residual dental elements are precarious because of root caries and periodontal problems. Prostheses are usually old (on average 15) and appear scarcely retentive and unstable. We believe in the need for specific interventions aiming at the various issues emerging from the present study, so as to achieve a smaller prevalence of dental loss, periodontal disease and caries. These relatively simple interventions are now lacking because of the non-demand of treatment from patients and for economical reasons

An audit of TB prevention on Italian health care workers

Tuberculosis (TB) is considered an occupational disease in health care workers. The aim of this study is to asses the state of tuberculosis prevention among the personnel of the Vaccina- tion Services of the Puglia Region (Italy), who were given an interview-based standardised questionnaire. Of the 302 replies, TB screening had been undergone by 80.5%, whom 78.6% took advice by the occupational health physician. Of those who were negative to the PPD skin test, 60.6% had received BCG, whom 78% took vaccination advice by the occupational health physi- cian. In Italy, the procedures for the monitoring and prevention of tuberculosis are a consolidated practice for occupational health physicians

Traumatic experiences in childhood and adolescence: a meta-analysis of prospective studies assessing risk for psychosis

Evidence of the association between traumatic experiences and psychosis are uncertain with respect to temporal order, clinical outcomes and the role of the age and genetic liability. The aim of the present meta-analysis was to explore the temporal relationship between the development of psychosis and traumatic exposure using prospective studies and to examine the role of moderation factors on overall effect sizes. Studies were identified by searching Embase-Ovid, PsycINFO (EBSCO), Pubmed, Scopus, Web of Science databases, and yielded an initial total of 9016 papers, leaving finally 23 after the screening process. Three sets of meta-analyses estimated the risk of developing psychotic experiences or full clinical psychosis by having experienced maltreatment by an adult or bullying by peers or parental death, using the random-effects model. Bullying by peers (OR = 2.28 [1.64, 4.34]), maltreatment by an adult (OR = 2.20 [1.72, 2.81]) and parental death (OR = 1.24 [1.06, 1.44]) all increased the risk of psychosis. Moderator analysis showed that negative effects of bullying were detected especially in those with genetic liability for psychosis and exposure to multiple trauma types; studies with higher prevalence of males showed a stronger risk for those exposed to parental death. No significant meta-regression was found between the risk of developing a full clinical psychosis or a psychotic experience. Lack of studies hampered the results about the age of trauma occurrence. The cumulative effect of being bullied from peers and experiencing other adversities during childhood and/or adolescence, together with genetic liability for psychosis, appears to confer the highest risk for developing psychotic symptoms later in life

Macroscopic quantum tunnelling in spin filter ferromagnetic Josephson junctions.

The interfacial coupling of two materials with different ordered phases, such as a superconductor (S) and a ferromagnet (F), is driving new fundamental physics and innovative applications. For example, the creation of spin-filter Josephson junctions and the demonstration of triplet supercurrents have suggested the potential of a dissipationless version of spintronics based on unconventional superconductivity. Here we demonstrate evidence for active quantum applications of S-F-S junctions, through the observation of macroscopic quantum tunnelling in Josephson junctions with GdN ferromagnetic insulator barriers. We show a clear transition from thermal to quantum regime at a crossover temperature of about 100 mK at zero magnetic field in junctions, which present clear signatures of unconventional superconductivity. Following previous demonstration of passive S-F-S phase shifters in a phase qubit, our result paves the way to the active use of spin filter Josephson systems in quantum hybrid circuits.We acknowledge financial support from COST Action MP1201 [NanoSC COST], by Progetto FIRB HybridNanoDev RBFR1236VV001 and by Regione Campania through POR Campania FSE 2007/2013, progetto MASTRI CUP B25B09000010007.This is the final version. It was first published by NPG at http://www.nature.com/ncomms/2015/150609/ncomms8376/full/ncomms8376.html#abstract

Risk factors for HBV/HIV/HCV in drug addicts: a survey of attendees of a Department of Pathological Dependence

Introduction. This study aims to determine risk factors for the acquisition of HIV, HBV and HCV infections among Injection Drug Users (IDUs) who attended the out-patient clinic of the Department of Pathological Dependence at Bari Hospital in Bari Province (Italy). Methods. The study was conducted in the year 2008 using the information available in the out-patient files of 291 drug addicts who were undergoing treatment. Results. Their average age was 29.3 and 133 (45.7%) of them were affected by HIV/ HBV/ HCV. The use of injected heroin, being separated or divorced, and having committed a crime were found to be risk factors for infection by HIV/ HBV/ HCV, while having a school diploma or a university degree and the use of cannabinoids were negatively associated with the infective diseases. Discussion and conclusions. While the data from the Italian Departments of Pathological Dependence concerning HIV diffusion in treated patients have been showing a reduction in the number of cases of seropositivity, drug addiction in industrialized countries is still the second most important risk factor, after promiscuous sexual behaviour, for infection by parenteral transmission. Correct risk assessment is essential for the planning of effective strategies for primary and secondary prevention