380 research outputs found
Teleportation between distant qudits via scattering of mobile qubits
We consider a one-dimensional (1D) structure where non-interacting spin-
scattering centers, such as quantum impurities or multi-level atoms, are
embedded at given positions. We show that the injection into the structure of
unpolarized flying qubits, such as electrons or photons, along with {path}
detection suffice to accomplish spin-state teleportation between two centers
via a third ancillary one. {No action over the internal quantum state of both
the spin- particles and the flying qubits is required. The protocol enables
the transfer of quantum information between well-seperated static entities in
nanostructures by exploiting a very low-control mechanism, namely scattering.Comment: 8 pages, 5 figure
Semantic priming study of Russian aspect and resultativity
This paper reports four priming experiments, in which resultative, processual, and delimitative Russian verbs were tested. The experiments were based on the semantic decision task: the participants had to decide whether the target denoted an event / situation with a clear outcome. To assess the impact of morphological cues on the decision latencies, verbs of different morphological complexity (prefixed and unprefixed perfectives) were used. The results obtained suggest that the aspectual feature of resultativity is consistently exploited in semantic priming (processual targets were primed in two experiments), and that the morphological cues facilitate the identification of resultative targets (prefixed perfectives exhibited faster decision latencies than unprefixed perfectives). As far as the delimitative forms are concerned, a category-induction experiment was designed to investigate the subjects’ tendency to group them with resultatives or with processuals, since the delimitatives represent an in-between category. The proportion of yes/no answers confirmed that the speakers place the delimitatives between these two domains, but much closer to the processuals than to the resultatives. These findings support the distinction of boundedness vs. telicity from both the theoretical and the behavioural perspective. The fact that the resultative interpretation of the delimitatives was not ruled out completely for most verbs suggests that, when certain conditions are met (when no cognate resultative form is readily available and when the delimitative is frequent enough), the delimitative can be conceptualized as the perfective counterpart of the basic imperfective, thus taking on the prototypical perfective role (resultativity)
Effect of Static Disorder in an Electron Fabry-Perot Interferometer with Two Quantum Scattering Centers
In a recent paper -- F. Ciccarello \emph{et al.}, New J. Phys. \textbf{8},
214 (2006) -- we have demonstrated that the electron transmission properties of
a one-dimensional (1D) wire with two identical embedded spin-1/2 impurities can
be significantly affected by entanglement between the spins of the scattering
centers. Such effect is of particular interest in the control of transmission
of quantum information in nanostructures and can be used as a detection scheme
of maximally entangled states of two localized spins. In this letter, we relax
the constraint that the two magnetic impurities are equal and investigate how
the main results presented in the above paper are affected by a static disorder
in the exchange coupling constants of the impurities. Good robustness against
deviation from impurity symmetry is found for both the entanglement dependent
transmission and the maximally entangled states generation scheme.Comment: 4 pages, 5 figure
The Curious Case of Metonymic Verbs: A Distributional Characterization
Logical metonymy combines an event-selecting verb with an entity-denoting noun (e.g.,The writer began the novel), triggering a covert event interpretation (e.g., reading, writing). Experimental investigations of logical metonymy must assume a binary distinction between metonymic (i.e. event-selecting) verbs and non-metonymic verbs to establish a control condition. However, this binary distinction (whether a verb is metonymic or not) is mostly made on intuitive grounds, which introduces a potential confounding factor.
We describe a corpus-based approach which characterizes verbs in terms of their behavior at the syntax-semantics interface. The model assesses the extent to which transitive verbs prefer event-denoting objects over entity-denoting objects. We then test this “eventhood” measure on
psycholinguistic datasets, showing that it can distinguish not only metonymic from non-metonymic
verbs, but that it can also capture more fine-grained distinctions among different classes of metonymic
verbs, putting such distinctions into a new graded perspective
Fitting, Not Clashing! A Distributional Semantic Model of Logical Metonymy
Logical metonymy interpretation (e.g. begin the book ->writing) has received wide attention in linguistics. Experimental results have shown higher processing costs for metonymic conditions compared with non-metonymic ones (
read the book). According to a widely held interpretation, it is
the type clash between the event-selecting verb and the entity-denoting object (begin the book) that triggers coercion mechanisms and leads to additional processing effort. We propose an alternative explanation and argue that the extra processing effort is an effect of thematic fit. This is a more
economical hypothesis that does not need to postulate a separate type clash mechanism: entity-denoting objects simply have a low fit as objects of event-selecting verbs. We test linguistic datasets from psycholinguistic experiments and find that a structured distributional model of thematic fit,
which does not encode any explicit argument type information, is able to replicate all significant experimental findings. This result provides evidence for a graded account of coercion phenomena in which thematic fit accounts for both the trigger of the coercion and the retrieval of the covert even
Implementing quantum gates through scattering between a static and a flying qubit
We investigate whether a two-qubit quantum gate can be implemented in a
scattering process involving a flying and a static qubit. To this end, we focus
on a paradigmatic setup made out of a mobile particle and a quantum impurity,
whose respective spin degrees of freedom couple to each other during a
one-dimensional scattering process. Once a condition for the occurrence of
quantum gates is derived in terms of spin-dependent transmission coefficients,
we show that this can be actually fulfilled through the insertion of an
additional narrow potential barrier. An interesting observation is that under
resonance conditions the above enables a gate only for isotropic Heisenberg
(exchange) interactions and fails for an XY interaction. We show the existence
of parameter regimes for which gates able to establish a maximum amount of
entanglement can be implemented. The gates are found to be robust to variations
of the optimal parameters.Comment: 7 pages, 3 figure
Management of direct oral anticoagulants in patients with atrial fibrillation undergoing cardioversion
Atrial fibrillation the most common cardiac arrhythmia. Its incidence rises steadily with each decade, becoming a real "epidemic phenomenon". Cardioversion is defined as a rhythm control strategy which, if successful, restores normal sinus rhythm. This, whether obtained with synchronized shock or with drugs, involves a periprocedural risk of stroke and systemic embolism which is reduced by adequate anticoagulant therapy in the weeks before or by the exclusion of left atrial thrombi. Direct oral anticoagulants are safe, manageable, and provide rapid onset of oral anticoagulation; they are an important alternative to heparin/warfarin from all points of view, with a considerable reduction in bleedings and increase in the safety and quality of life of patients
Entanglement Controlled Single-Electron Transmittivity
We consider a system consisting of single electrons moving along a 1D wire in
the presence of two magnetic impurities. Such system shows strong analogies
with a Fabry - Perot interferometer in which the impurities play the role of
two mirrors with a quantum degree of freedom: the spin. We have analysed the
electron transmittivity of the wire in the presence of entanglement between the
impurity spins. The main result of our analysis is that, for suitable values of
the electron momentum, there are two maximally entangled state of the impurity
spins the first of which makes the wire transparent whatever the electron spin
state while the other strongly inhibits the electron transmittivity. Such
predicted striking effect is experimentally observable with present day
technology.Comment: Published version (6 figures
Socio-demographic factors involved in a low-incidence phase of sars-cov-2 spread in sicily, italy
Background: The present study analysed SARS-CoV-2 cases observed in Sicily and investigated social determinants that could have an impact on the virus spread. Methods: SARS-CoV-2 cases observed among Sicilian residents between the 1 February 2020 and 15 October 2020 have been included in the analyses. Age, sex, date of infection detection, residency, clinical outcomes, and exposure route have been evaluated. Each case has been linked to the census section of residency and its socio-demographic data. Results: A total of 10,114 patients (202.3 cases per 100,000 residents; 95% CI = 198.4–206.2) were analysed: 45.4% were asymptomatic and 3.62% were deceased during follow-up. Asymptomatic or mild cases were more frequent among young groups. A multivariable analysis found a reduced risk of SARS-CoV-2 cases was found in census sections with higher male prevalence (adj-OR = 0.99, 95% CI = 0.99–0.99; p < 0.001) and presence of immigrants (adj-OR = 0.89, 95% CI 0.86–0.92; p < 0.001). Proportion of residents aged <15 years, residents with a university degree, residents with secondary education, extra-urban mobility, presence of home for rent, and presence of more than five homes per building were found to increase the risk of SARS-CoV-2 incidence. Conclusion: Routinely collected socio-demographic data can be predictors of SARS-CoV-2 risk infection and they may have a role in mapping high risk micro-areas for virus transmission
Extracellular vesicles in airway homeostasis and pathophysiology
The epithelial–mesenchymal trophic unit (EMTU) is a morphofunctional entity involved in the maintenance of the homeostasis of airways as well as in the pathogenesis of several diseases, including asthma and chronic obstructive pulmonary disease (COPD). The “muco-microbiotic layer” (MML) is the innermost layer of airways made by microbiota elements (bacteria, viruses, archaea and fungi) and the surrounding mucous matrix. The MML homeostasis is also crucial for maintaining the healthy status of organs and its alteration is at the basis of airway disorders. Nanovesicles produced by EMTU and MML elements are probably the most important tool of communication among the different cell types, including inflammatory ones. How nanovesicles produced by EMTU and MML may affect the airway integrity, leading to the onset of asthma and COPD, as well as their putative use in therapy will be discussed here
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