Quantum Random Number Generator using Photon-Number Path Entanglement

We report a novel quantum random number generator based on the photon-number$-$path entangled state which is prepared via two-photon quantum interference at a beam splitter. The randomness in our scheme is of truly quantum mechanical origin as it comes from the projection measurement of the entangled two-photon state. The generated bit sequences satisfy the standard randomness test

Knowledge, source of information, and perception of Portuguese medical students and junior doctors of infection control precautions

Medical education should include infection control precautions (ICPs). Portuguese medical students showed reasonable knowledge in ICPs; however, contact isolation and glove and mask use should be reinforced. Only 25% referred to the curriculum as the most important information source. There was a positive association between academic year (P = .032), previous training in ICPs (P = .016), and knowledge. Main strategies proposed to acquire competences in ICPs were bedside teaching (26.9%) and curriculum and bedside teaching (20.2%)

The Relationship between Income and Oral Health: A Critical Review

In this critical review, we summarized the evidence on associations between individual/household income and oral health, between income inequality and oral health, and income-related inequalities in oral health. Meta-analyses of mainly cross-sectional studies confirm that low individual/household income is associated with oral cancer (odds ratio, 2.41; 95% confidence interval [CI], 1.59–3.65), dental caries prevalence (prevalence ratio, 1.29; 95% CI, 1.18–1.41), any caries experience (odds ratio, 1.40; 95% CI, 1.19–1.65), tooth loss (odds ratio, 1.66; 95% CI, 1.48–1.86), and traumatic dental injuries (odds ratio, 0.76; 95% CI, 0.65–0.89). Reviews also confirm qualitatively that low income is associated with periodontal disease and poor oral health–related quality of life. Limited evidence from the United States shows that psychosocial and behavioral explanations only partially explain associations between low individual/household income and oral health. Few country-level studies and a handful of subnational studies from the United States, Japan, and Brazil show associations between area-level income inequality and poor oral health. However, this evidence is conflicting given that the association between area-level income inequality and oral health outcomes varies considerably by contexts and by oral health outcomes. Evidence also shows cross-national variations in income-related inequalities in oral health outcomes of self-rated oral health, dental care, oral health–related quality of life, outcomes of dental caries, and outcomes of tooth loss. There is a lack of discussion in oral health literature about limitations of using income as a measure of social position. Future studies on the relationship between income and oral health can benefit substantially from recent theoretical and methodological advancements in social epidemiology that include application of an intersectionality framework, improvements in reporting of inequality, and causal modeling approaches. Theoretically well-informed studies that apply robust epidemiological methods are required to address knowledge gaps for designing relevant policy interventions to reduce income-related inequalities in oral health

Quantum erasure with causally disconnected choice

The counterintuitive features of quantum physics challenge many common-sense assumptions. In an interferometric quantum eraser experiment, one can actively choose whether or not to erase which-path information, a particle feature, of one quantum system and thus observe its wave feature via interference or not by performing a suitable measurement on a distant quantum system entangled with it. In all experiments performed to date, this choice took place either in the past or, in some delayed-choice arrangements, in the future of the interference. Thus in principle, physical communications between choice and interference were not excluded. Here we report a quantum eraser experiment, in which by enforcing Einstein locality no such communication is possible. This is achieved by independent active choices, which are space-like separated from the interference. Our setup employs hybrid path-polarization entangled photon pairs which are distributed over an optical fiber link of 55 m in one experiment, or over a free-space link of 144 km in another. No naive realistic picture is compatible with our results because whether a quantum could be seen as showing particle- or wave-like behavior would depend on a causally disconnected choice. It is therefore suggestive to abandon such pictures altogether

Update on atmospheric neutrinos

We discuss the impact of recent experimental results on the determination of atmospheric neutrino oscillation parameters. We use all published results on atmospheric neutrinos, including the preliminary large statistics data of Super-Kamiokande. We reanalyze the data in terms of both vμ → vτ and vμ → ve channels using new improved calculations of the atmospheric neutrino flux. We compare the sensitivity attained in atmospheric neutrino experiments with those of accelerator and reactor neutrino oscillation searches, including the recent CHOOZ experiment. We briefly comment on the implications of atmospheric neutrino data in relation to future searches for neutrino oscillations with long baselines, such as the K2K, MINOS, ICARUS, and NOE experiments.MC is obtained by folding a prediction for the atmospheric neutrino flux with the properties of every individual detector through a Monte Carlo ~MC! procedure. Apart from studying the impact of the new data, our motivation for the present reanalysis of atmospheric neutrino data is theoretical. In this regard, we first of all include the results of a recent calculation of the atmospheric neutrino fluxes as a function of zenith angles @11#, including the muon polarization effect @12#. Moreover, we develop an independent procedure for the comparison of results from different experiments. We demonstrate that our theoretical calculation of the energy distribution of the event rates is in good agreement with the MC expectations. The comparison of the experimental results presented below thus reflects the significance of the atmospheric neutrino anomaly and provides evidence for neutrino oscillations. In this paper we analyze the impact of recent experimental results on atmospheric neutrinos from Super-Kamiokande and Soudan2 on the determinations of atmospheric neutrin

Social and dental status along the life course and oral health impacts in adolescents: a population-based birth cohort

<p>Abstract</p> <p>Background</p> <p>Harmful social conditions in early life might predispose individuals to dental status which in turn may impact on adolescents' quality of life.</p> <p>Aims</p> <p>To estimate the prevalence of oral health impacts among 12 yr-old Brazilian adolescents (<it>n </it>= 359) and its association with life course socioeconomic variables, dental status and dental services utilization in a population-based birth cohort in Southern Brazil.</p> <p>Methods</p> <p>Exploratory variables were collected at birth, at 6 and 12 yr of age. The Oral Impacts on Daily Performances index (OIDP) was collected in adolescence and it was analyzed as a ranked outcome (OIDP from 0 to 9). Unadjusted and adjusted multivariable Poisson regression with robust variance was performed guided by a theoretical determination model.</p> <p>Results</p> <p>The response rate was of 94.4% (<it>n </it>= 339). The prevalence of OIDP = 1 was 30.1% (CI95%25.2;35.0) and OIDP ≥ 2 was 28.0% (CI95%23.2;32.8). The most common daily activity affected was eating (44.8%), follow by cleaning the mouth and smiling (15.6%, and 15.0%, respectively). In the final model mother schooling and mother employment status in early cohort participant's life were associated with OIDP in adolescence. As higher untreated dental caries at age 6 and 12 years, and the presence of dental pain, gingival bleeding and incisal crowing in adolescence as higher the OIDP score. On the other hand, dental fluorosis was associated with low OIDP score.</p> <p>Conclusion</p> <p>Our findings highlight the importance of adolescent's early life social environmental as mother schooling and mother employment status and the early and later dental status on the adolescent's quality of life regardless family income and use of dental services.</p

Random qubit-states and how best to measure them

We consider the problem of measuring a single qubit, known to have been prepared in either a randomly selected pure state or a randomly selected real pure state. We seek the measurements that provide either the best estimate of the state prepared or maximise the accessible information. Surprisingly, any sensible measurement turns out to be optimal. We discuss the application of these ideas to multiple qubits and higher-dimensional systems

Entanglement and teleportation via chaotic system

The dynamics of entangled state interacting with a single cavity mode is investigated in the presence of a random parameter. We have shown that degree of entanglement decays with time and rate of decay is defined by features of random parameter. Quantum teleportation through dissipative channal and teleportation fidelity as a function of damping rates has been studied. The sensitivity of the fidelity with respect to random parameter is discussed. We have evaluated the time interval during which one can perform the quantum teleportation and send the information with reasonable fidelity, for a given values of correlation length of random parameter.Comment: Accepted in Physica

\mu-\tau Symmetry and Maximal CP Violation

We argue the possibility that a real part of a flavor neutrino mass matrix only respects a mu-tau symmetry. This possibility is shown to be extended to more general case with a phase parameter \theta, where the mu-tau symmetric part has a phase of \theta/2. This texture shows maximal CP violation and no Majorana CP violation.Comment: 5 pages, version to appear in Phys. Lett.