Constraint on Neutrino Decay with Medium-Baseline Reactor Neutrino Oscillation Experiments

The experimental bound on lifetime of nu_3, the neutrino mass eigenstate with the smallest nu_e component, is much weaker than those of nu_1 and nu_2 by many orders of magnitude to which the astrophysical constraints apply. We argue that the future reactor neutrino oscillation experiments with medium-baseline (~ 50 km), such as JUNO or RENO-50, has the best chance of placing the most stringent constraint on nu_3 lifetime among all neutrino experiments which utilize the artificial source neutrinos. Assuming decay into invisible states, we show by a detailed chi^2 analysis that the nu_3 lifetime divided by its mass, tau_3/m_3, can be constrained to be tau_3/m_3 > 7.5 (5.5) x 10^{-11} s/eV at 95% (99%) C.L. by 100 kt.years exposure by JUNO. It may be further improved to the level comparable to the atmospheric neutrino bound by its longer run. We also discuss to what extent nu_3 decay affects mass-ordering determination and precision measurements of the mixing parameters.Comment: 23 pages, 6 figures, clarification of some discussions, added some references, no change in results and conclusions, version accepted for publication in JHE

Boson Sampling with efficient scaling and efficient verification

A universal quantum computer of moderate scale is not available yet, however intermediate models of quantum computation would still permit demonstrations of a quantum computational advantage over classical computing and could challenge the Extended Church-Turing Thesis. One of these models based on single photons interacting via linear optics is called Boson Sampling. Proof-of-principle Boson Sampling has been demonstrated, but the number of photons used for these demonstrations is below the level required to claim quantum computational advantage. To make progress with this problem, here we conclude that the most practically achievable pathway to scale Boson Sampling experiments with current technologies is by combining continuous-variables quantum information and temporal encoding. We propose the use of switchable dual-homodyne and single-photon detections, the temporal loop technique and scattershot based Boson Sampling. This proposal gives details as to what the required assumptions are and a pathway for a quantum optical demonstration of quantum computational advantage. Furthermore, this particular combination of techniques permits a single efficient implementation of Boson Sampling and efficient verification in a single experimental setup

Resources Package Modelling Supporting Border Surveillance Operations

The purpose of this work is to propose a military planning tool capable of providing logistical bases and patrol packages to most effectively support border surveillance. Presently, military patrols are employed along geographical borders to combat transnational crimes; acts such as drug trafficking, smuggling of goods and illegal natural resources exploitation. The patrols make temporary stops within specific time windows at specific places characterised by a high incidence of crime (hotspots). These hotspots have different criticalities within given time windows. To optimise the results, the proposed model allows additional stops in more critical hotspots. It achieves this using a mathematical optimisation model. Considering that there are not adequate logistical-military capacities (logistical bases and patrols) at all needed locations, developing a border surveillance plan that optimises resource use is imperative. The model was run using black hole-based optimisation and a real patrol mission’s database to ensure timely solutions. The solutions were then evaluated in terms of quality (number of bases and patrols, coverage efforts, and travel time) and computational processing time. Next, they were compared with solutions using the traditional method, thereby demonstrating the model’s robustness in providing timely surveillance schemes that ensure high coverage with minimum resources

Quantum metrology timing limits of the Hong-Ou-Mandel interferometer and of general two-photon measurements

We examine the precision limits of Hong-Ou-Mandel (HOM) timing measurements, as well as precision limits applying to generalized two-photon measurements. As a special case, we consider the use of two-photon measurements using photons with variable bandwidths and frequency correlations. When the photon bandwidths are not equal, maximizing the measurement precision involves a trade-off between high interference visibility and strong frequency anticorrelations, with the optimal precision occuring when the photons share non-maximal frequency anticorrelations. We show that a generalized measurement has precision limits that are qualitatively similar to those of the HOM measurement whenever the generalized measurement is insensitive to the net delay of both photons. By examining the performance of states with more general frequency distributions, our analysis allows for engineering of the joint spectral amplitude for use in realistic situations, in which both photons may not have ideal spectral properties.Comment: 12 pages, 6 figures; resubmissio

Spectral characterization of a SPDC source with a fast broadband spectrometer

Knowing the properties of the single photons produced in a Spontaneous Parametric Down-Conversion (SPDC) source can be crucial for specific applications and uses. In particular, the spectral properties are of key relevance. Here, we investigate a commercial SPDC source using our fast broadband spectrometer. Our analysis is a valid method for other SPDC sources, as well as other single-photon generation techniques, thus providing a good example of how to use this spectrometer design. We calibrate the spectrometer using known lines of the argon emission spectrum. We show that the two down-converted photons from the SPDC source have different spectral properties depending on the pump power, and in which condition we measured spectrally similar down-converted photons. Lastly, we were able to reconstruct and investigate the spectral information for the pump photon

Fast spectrometer near the Heisenberg limit with direct measurement of time and frequency for multiple single photons

We present a single-photon-sensitive spectrometer, based on a linear array of 512 single-photon avalanche diodes, with 0.04 nm spectral and 40 ps temporal resolutions. We employ a fast data-driven operation that allows direct measurement of time and frequency for simultaneous single photons. Combining excellent temporal and spectral resolution, our result is only a factor of ten above the Heisenberg Uncertainty Principle limit of hbar/2 for energy and time, despite the simplicity of our experimental setup. This work opens numerous applications in quantum photonics, especially when both spectral and temporal properties of single photons are exploited

Avaliação da qualidade vocal de crianças sem queixas vocais: estudo prospectivo duplo-cego

OBJECTIVE: To evaluate the vocal quality of children without voice disorders, analyzing the possible presence and type of lesion, glottic coaptation and laryngeal constriction, roughness and breathiness vocal quality.MATERIALS AND METHODS: We evaluated 50 male children, aged 3 to 10, randomly selected, who did not present otorhinolaryngological disorders. All children went through an otorhinolaryngological exam, followed by videofibrolaryngoscopy and speech pathology evaluation.RESULTS: Out of the 50 children, 25 were classified as normal. Eight presented with cysts, and 17 had vocal nodules. We observed that normal vocal quality was significant in the normal group, while roughness and breathness were associated with the pathological group. We did not find a significant difference in vocal quality when we analyzed glottic coaptation and laryngeal constriction.CONCLUSIONS: Roughness and breathness were significantly associated with structural lesions of the vocal fold, while a normal vocal quality was associated with absence of structural lesions. The authors concluded that all signs of roughness or breathness should be considered in order to allow an early diagnosis of laryngeal alterations and, consequently, early treatment.OBJETIVO: Avaliar a qualidade vocal de crianças que não apresentam queixas de distúrbios na voz. As crianças foram analisadas quanto à possível presença e tipo delesão, quanto ao tipo de coaptação das pregas vocais, e quanto à rouquidão, aspereza e soprosidade da voz.MATERIAIS E MÉTODOS: Foram avalidas 50 crianças do sexo masculino, escolhidas aleatoriamente, na faixa etária de 3 a 10 anos, que não apresentavam queixasotorrinolaringológicas. To das as crianças passaram por exame otorrinolaringológico, seguido de videofibrolaringoscopia e avaliação fonoaudiolóigica.RESULTADOS: Das 50 crianças, 25 foram classificadas como normais. Oito eram portadoras de cisto e 17, portadoras de nódulo vocal, todas sem queixas vocais.Observamos que a qualidade vocal normal esteve presente de maneira significativa no grupo normal, enquanto a rouquidão e a soprosidade estiveram associadas de maneira significativa ao grupo patológico. Nós não observamos diferença significativaquanto a qualidade vocal ao analisarmos a coaptação glótica e a constrição laríngea.CONCLUSÕES: A qualidade vocal do tipo rouca e soprosa está associada de maneira significativa às com lesão estrutural das pregas vocais e a qualidade vocal normal, às crianças sem lesão estrutural. Assim, deve-se atentar para a presença de rouquidão em crianças de forma a permitir o diagnóstico precoce de alterações laríngeas e, conseqüentemente, a terapêutica

Procedural and physical interventions for vaccine injections systematic review of randomized controlled trials and quasi-randomized controlled trials

Background: This systematic review evaluated the effectiveness of physical and procedural interventions for reducing pain and related outcomes during vaccination. Design/Methods: Databases were searched using a broad search strategy to identify relevant randomized and quasi-randomized controlled trials. Data were extracted according to procedure phase (preprocedure, acute, recovery, and combinations of these) and pooled using established methods. Results: A total of 31 studies were included. Acute infant distress was diminished during intramuscular injection without aspiration (n=313): standardized mean difference (SMD) -0.82 (95% confidence interval [CI]: -1.18, -0.46). Injecting the most painful vaccine last during vaccinations reduced acute infant distress (n=196): SMD -0.69 (95%CI: -0.98, -0.4). Simultaneous injections reduced acute infant distress compared with sequential injections (n=172): SMD -0.56 (95%CI: -0.87, -0.25). There was no benefit of simultaneous injections in children. Less infant distress during the acute and recovery phases combined occurred with vastus lateralis (vs. deltoid) injections (n=185): SMD -0.70 (95%CI: -1.00, -0.41). Skin-to-skin contact in neonates (n=736) reduced acute distress: SMD -0.65 (95% CI: -1.05, -0.25). Holding infants reduced acute distress after removal of the data from 1 methodologically diverse study (n=107): SMD -1.25 (95% CI: -2.05, -0.46). Holding after vaccination (n=417) reduced infant distress during the acute and recovery phases combined: SMD -0.65 (95% CI: -1.08, -0.22). Self-reported fear was reduced for children positioned upright (n=107): SMD -0.39 (95% CI: -0.77, -0.01). Non-nutritive sucking (n=186) reduced acute distress in infants: SMD -1.88 (95% CI: -2.57, -1.18). Manual tactile stimulation did not reduce pain across the lifespan. An external vibrating device and cold reduced pain in children (n=145): SMD -1.23 (95% CI: -1.58, -0.87). There was no benefit of warming the vaccine in adults. Muscle tension was beneficial in selected indices of fainting in adolescents and adults. Conclusions: Interventions with evidence of benefit in select populations include: no aspiration, injecting most painful vaccine last, simultaneous injections, vastus lateralis injection, positioning interventions, non-nutritive sucking, external vibrating device with cold, and muscle tension

Contraction amplitude is a relevant predictor of bolus transit during sitting viscous solution swallows in healthy individuals : preliminary results of a multicenter study using high resolution impedance manometry (HRIM)

Q1Q1https://orcid.org/0000-0002-9219-4548https://orcid.org/0000-0003-1222-0636https://orcid.org/0000-0002-4523-7947Revista Internacional - Indexad