872 research outputs found

    Quantum Randomness Certified by the Uncertainty Principle

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    We present an efficient method to extract the amount of true randomness that can be obtained by a Quantum Random Number Generator (QRNG). By repeating the measurements of a quantum system and by swapping between two mutually unbiased bases, a lower bound of the achievable true randomness can be evaluated. The bound is obtained thanks to the uncertainty principle of complementary measurements applied to min- and max- entropies. We tested our method with two different QRNGs, using a train of qubits or ququart, demonstrating the scalability toward practical applications.Comment: 10 page

    Hyperentangled mixed phased Dicke states: optical design and detection

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    We present an experimental method to produce 4-qubit phased Dicke states, based on a source of 2-photon hyperentangled states. By introducing quantum noise in the multipartite system in a controlled way, we have tested the robustness of these states. To this purpose the entanglement of the resulting multipartite entangled mixed states has been verified by using a new kind of structural witness.Comment: 6 pages, 3 figure, supplementary information include

    Effects of Force Level and Hand Dominance on Bilateral Transfer of a Fine Motor Skill

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    Our research is about bilateral transfer, a concept in motor learning where skills learned by one limb are "transferred", allowing the opposite limb to benefit from what was learned by the first limb. Previous research into bilateral transfer has raised questions about whether specific aspects of motor coordination are or are not transferred. We wanted to see whether learning to control pinch force by the thumb and index finger is transferable, and if it is, whether the learning transfers equally from either hand. We also want to look into the effects of different force levels on the degree of transfer. We designed a task using a program that takes force levels as inputs and has the participant trace shapes on a screen. By having participants perform with one hand, then practice with the other, and finally perform again with the initial hand, we can measure transfer as the difference in performance before and after practice with the other hand.Kinesiology and Health Educatio

    Enhancing the Violation of the Einstein-Podolsky-Rosen Local Realism by Quantum Hyper-entanglement

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    Mermin's observation [Phys. Rev. Lett. {\bf 65}, 1838 (1990)] that the magnitude of the violation of local realism, defined as the ratio between the quantum prediction and the classical bound, can grow exponentially with the size of the system is demonstrated using two-photon hyper-entangled states entangled in polarization and path degrees of freedom, and local measurements of polarization and path simultaneously.Comment: Minor errors corrected. To appear on Physical Review Letter

    'ACCORD' e-Platform: Development and evaluation of an innovative multicultural training for school professionals

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    The study aims at describing the development, application and evaluation of ACCORD, an innovative e-platform offering a free-accessible tailored multicultural training for school professionals through the application of current ICT research (e-learning, mobility, internet, artificial intelligence). The eplatform provided school professionals with a dedicated Massive Online Open Course (MOOC) and a Serious Game (SG), embedded within it, useful to enhance and (self-)evaluate their intercultural competences and negotiation abilities. Technological, Psychological, and Pedagogical models and approaches underpinned the methodology driving the creation of the e-platform contents. Following a pilot test, the edited version of the e-platform (including the SG, learning materials, lessons, questionnaires) was widely diffused in different languages (English, German, Italian, Flemish, Spanish). Pre- and post-training questionnaires were used to assess the learning experience and the efficacy of the training. Findings provided evidence supporting the learning effectiveness of ACCORD training. The experience with the e-platform has been positively rated by the users concerning both the technological and educational aspects. Overall, the study provided an overview on the creation, implementation and evaluation of a novel multicultural training tool, which has been proven to effectively foster the enhancement of intercultural and interethnic competencies of professionals working in the European educational contexts

    Effetti cardiorespiratori degli sprint ripetuti in giovani calciatori

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    Scopo: Nel calcio la performance dipende da attività caratterizzate da sforzi di breve durata, talora ad alta intensità, con ridotti tempi di recupero. Questo tipo di sforzo può avere maggiore potenzialità aritmogena rispetto a sforzi, anche massimali, iniziati e terminati in modo graduale. Gli sprint ripetuti permettono di valutare la performance e lo stato di allenamento in giovani calciatori. Scopo del nostro lavoro è stato quello di valutare gli effetti degli sprint ripetuti sul sistema cardiorespiratorio in giovani calciatori delle rappresentative regionali siciliane della FIGC. Metodi: Sono stati esaminati 12 calciatori, di età media di 15±1 anni. Per valutare lo stato di fitness cardiorespiratoria sono stati determinati, al test da sforzo incrementale massimale al treadmill (SI), il VO2max in ml.Kg-1.min-1 (VO2maxSI) e la FCmax in bpm (FCmaxSI). Per valutare gli effetti cardiorespiratori degli sprint ripetuti, gli atleti hanno eseguito un test da sforzo al cicloergometro a freno meccanico (SR) che prevedeva 10 sprint massimali “all-out” di 6 sec, intervallati da 30 sec di recupero passivo. Nella serie dei 10 sprint, sono stati determinati il valore più elevato di VO2 in ml.Kg-1.min-1 (VO2maxSR) e di FC in bpm (FCmaxSR). Risultati: Il valore medio di VO2maxSI (56,22±3,93 ml.Kg-1.min-1) indica che i soggetti esaminati hanno un buon livello di potenza aerobica, raggiunta ad una FCmaxSI di 190±8 bpm. I dati di VO2maxSR rilevati al test degli sprint ripetuti evidenziano un valore medio di 42,67±5,57 ml.Kg-1.min-1 (70% del VO2maxSI), raggiunto ad una FCmaxSR di 175±11 bpm (92% della FCmaxSI). Conclusioni: I dati del nostro studio indicano che nei soggetti esaminati gli sprint ripetuti determinano incrementi della frequenza cardiaca rapidi, elevati e persistenti nella fase di recupero. Questo dato deve essere preso in considerazione non solo per la valutazione della performance ma anche nella formulazione dell’idoneità a praticare la disciplina sportiva del calcio

    Developmental stage-specific regulation of the circadian Clock by Temperature in Zebrafish

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    The circadian clock enables animals to adapt their physiology and behaviour in anticipation of the day-night cycle. Light and temperature represent two key environmental timing cues (zeitgebers) able to reset this mechanism and so maintain its synchronization with the environmental cycle. One key challenge is to unravel how the regulation of the clock by zeitgebers matures during early development. The zebrafish is an ideal model for studying circadian clock ontogeny since the process of development occurs ex utero in an optically transparent chorion and many tools are available for genetic analysis. However, the role played by temperature in regulating the clock during zebrafish development is poorly understood. Here, we have established a clock-regulated luciferase reporter transgenic zebrafish line (Tg (−3.1) per1b::luc) to study the effects of temperature on clock entrainment. We reveal that under complete darkness, from an early developmental stage onwards (48 to 72 hpf), exposure to temperature cycles is a prerequisite for the establishment of self-sustaining rhythms of zfper1b, zfaanat2, and zfirbp expression and also for circadian cell cycle rhythms. Furthermore, we show that following the 5–9 somite stage, the expression of zfper1b is regulated by acute temperature shifts

    Fully nonlocal quantum correlations

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    Quantum mechanics is a nonlocal theory, but not as nonlocal as the no-signalling principle allows. However, there exist quantum correlations that exhibit maximal nonlocality: they are as nonlocal as any non-signalling correlations and thus have a local content, quantified by the fraction pLp_L of events admitting a local description, equal to zero. Exploiting the link between the Kochen-Specker and Bell's theorems, we derive, from every Kochen-Specker proof, Bell inequalities maximally violated by quantum correlations. We then show that these Bell inequalities lead to experimental bounds on the local content of quantum correlations which are significantly better than those based on other constructions. We perform the experimental demonstration of a Bell test originating from the Peres-Mermin Kochen-Specker proof, providing an upper bound on the local content pL0.22p_L\lesssim 0.22.Comment: 9 pages, 5 figures and three tables. To appear in PR
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