933 research outputs found

    The Remains of the Day: The International Economic Order in the Era of Disintegration

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    The last two decades of the XX century have been marked by a vigorous acceleration of international economic integration both at a global and regional level. States accepted pervasive constraints on their national decision-making in the hope that stability and predictability would favor economic growth. This model of international economic integration, however, has recently shown worrying signs of ‘disintegration’. Disintegration manifests itself both as disintegration of the international legal regimes which compose the international economic order; and disintegration through law, namely the social, economic and environmental disintegration phenomena,triggered or at leastfacilitated by these regimes. Relying on the paradox integration/disintegration as an analytical framework, this article draws a blueprint of the various disintegration phenomena, which are further analyzed in the individual contributions to this Special Issue. It seeks to identify a relationship betweenthetwo dimensions of disintegration and detect possible correlation patterns. Last, after engaging with the different normative alternatives put forward by the contributors, it concludes by calling for a rethinking of the traditional approach to international economic integration. This reconceptualization should be premised on the full realization that the current model entails a great deal of environmental and social ‘hidden costs’

    Quantum Random Access Codes for Boolean Functions

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    An n↦pmn\overset{p}{\mapsto}m random access code (RAC) is an encoding of nn bits into mm bits such that any initial bit can be recovered with probability at least pp, while in a quantum RAC (QRAC), the nn bits are encoded into mm qubits. Since its proposal, the idea of RACs was generalized in many different ways, e.g. allowing the use of shared entanglement (called entanglement-assisted random access code, or simply EARAC) or recovering multiple bits instead of one. In this paper we generalize the idea of RACs to recovering the value of a given Boolean function ff on any subset of fixed size of the initial bits, which we call ff-random access codes. We study and give protocols for ff-random access codes with classical (ff-RAC) and quantum (ff-QRAC) encoding, together with many different resources, e.g. private or shared randomness, shared entanglement (ff-EARAC) and Popescu-Rohrlich boxes (ff-PRRAC). The success probability of our protocols is characterized by the \emph{noise stability} of the Boolean function ff. Moreover, we give an \emph{upper bound} on the success probability of any ff-QRAC with shared randomness that matches its success probability up to a multiplicative constant (and ff-RACs by extension), meaning that quantum protocols can only achieve a limited advantage over their classical counterparts.Comment: Final version to appear in Quantum. Small improvements to Theorem 2

    Femtosecond Covariance Spectroscopy

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    The success of non-linear optics relies largely on pulse-to-pulse consistency. In contrast, covariance based techniques used in photoionization electron spectroscopy and mass spectrometry have shown that wealth of information can be extracted from noise that is lost when averaging multiple measurements. Here, we apply covariance based detection to nonlinear optical spectroscopy, and show that noise in a femtosecond laser is not necessarily a liability to be mitigated, but can act as a unique and powerful asset. As a proof of principle we apply this approach to the process of stimulated Raman scattering in alpha-quartz. Our results demonstrate how nonlinear processes in the sample can encode correlations between the spectral components of ultrashort pulses with uncorrelated stochastic fluctuations. This in turn provides richer information compared to the standard non-linear optics techniques that are based on averages over many repetitions with well-behaved laser pulses. These proof-of-principle results suggest that covariance based nonlinear spectroscopy will improve the applicability of fs non-linear spectroscopy in wavelength ranges where stable, transform limited pulses are not available such as, for example, x-ray free electron lasers which naturally have spectrally noisy pulses ideally suited for this approach

    Ribosomal RNA Pseudouridylation: Will Newly Available Methods Finally Define the Contribution of This Modification to Human Ribosome Plasticity?

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    In human rRNA, at least 104 specific uridine residues are modified to pseudouridine. Many of these pseudouridylation sites are located within functionally important ribosomal domains and can influence ribosomal functional features. Until recently, available methods failed to reliably quantify the level of modification at each specific rRNA site. Therefore, information obtained so far only partially explained the degree of regulation of pseudouridylation in different physiological and pathological conditions. In this focused review, we provide a summary of the methods that are now available for the study of rRNA pseudouridylation, discussing the perspectives that newly developed approaches are offering

    A focus on Gozo

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    Heart was what the people needed during the darkest century of Gozo's history, and Don Lorenzo de Apapis was the man to provide it. For a skeletal biography of Don Lorenzo de Apapis there are three principal sources of information, namely, Monsignor Pietro Dusina's report of 1575, the notarial register of Don Lorenzo de Apapis, and Don Lorenzo de Apapis' last will and testament. When the Apostolic Visitor, Mons. Pietro Dusina, visited Gozo, in the year 1575, Don Lorenzo was 74 years old "etatis annorum septuaginta quatuor". Hence he was born circa 1501. In Dusina's report, Don Lorenzo is qualified as "Presbyter Gaulorum, et Vicarius Foraneus". We also learn from Dusina's report that Don Lorenzo was Parish Priest at the Parish Church of Saint George.peer-reviewe

    Hitting time for the continuous quantum walk

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    We define the hitting (or absorbing) time for the case of continuous quantum walks by measuring the walk at random times, according to a Poisson process with measurement rate λ\lambda. From this definition we derive an explicit formula for the hitting time, and explore its dependence on the measurement rate. As the measurement rate goes to either 0 or infinity the hitting time diverges; the first divergence reflects the weakness of the measurement, while the second limit results from the Quantum Zeno effect. Continuous-time quantum walks, like discrete-time quantum walks but unlike classical random walks, can have infinite hitting times. We present several conditions for existence of infinite hitting times, and discuss the connection between infinite hitting times and graph symmetry.Comment: 12 pages, 1figur

    Phenotyping Key Fruit Quality Traits in Olive Using RGB Images and Back Propagation Neural Networks

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    To predict oil and phenol concentrations in olive fruit, the combination of back propagation neural networks (BPNNs) and contact-less plant phenotyping techniques was employed to retrieve RGB image-based digital proxies of oil and phenol concentrations. Fruits of cultivars (×3) differing in ripening time were sampled (∼10-day interval, ×2 years), pictured and analyzed for phenol and oil concentrations. Prior to this, fruit samples were pictured and images were segmented to extract the red (R), green (G), and blue (B) mean pixel values that were rearranged in 35 RGB-based colorimetric indexes. Three BPNNs were designed using as input variables (a) the original 35 RGB indexes, (b) the scores of principal components after a principal component analysis (PCA) pre-processing of those indexes, and (c) a reduced number (28) of the RGB indexes achieved after a sparse PCA. The results show that the predictions reached the highest mean R2 values ranging from 0.87 to 0.95 (oil) and from 0.81 to 0.90 (phenols) across the BPNNs. In addition to the R2, other performance metrics were calculated (root mean squared error and mean absolute error) and combined into a general performance indicator (GPI). The resulting rank of the GPI suggests that a BPNN with a specific topology might be designed for cultivars grouped according to their ripening period. The present study documented that an RGB-based image phenotyping can effectively predict key quality traits in olive fruit supporting the developing olive sector within a digital agriculture domain
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