8,237 research outputs found

    Distributed Adaptive Learning of Graph Signals

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    The aim of this paper is to propose distributed strategies for adaptive learning of signals defined over graphs. Assuming the graph signal to be bandlimited, the method enables distributed reconstruction, with guaranteed performance in terms of mean-square error, and tracking from a limited number of sampled observations taken from a subset of vertices. A detailed mean square analysis is carried out and illustrates the role played by the sampling strategy on the performance of the proposed method. Finally, some useful strategies for distributed selection of the sampling set are provided. Several numerical results validate our theoretical findings, and illustrate the performance of the proposed method for distributed adaptive learning of signals defined over graphs.Comment: To appear in IEEE Transactions on Signal Processing, 201

    Determination of hidden variable models reproducing the spin-singlet

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    The experimental violation of Bell inequality establishes necessary but not sufficient conditions that any theory must obey. Namely, a theory compatible with the experimental observations can satisfy at most two of the three hypotheses at the basis of Bell's theorem: free will, no-signaling, and outcome-Independence. Quantum mechanics satisfies the first two hypotheses but not the latter. Experiments not only violate Bell inequality, but show an excellent agreement with quantum mechanics. This fact restricts further the class of admissible theories. In this work, the author determines the form of the hidden-variable models that reproduce the quantum mechanical predictions for a spin singlet while satisfying both the hypotheses of free will and no-signaling. Two classes of hidden-variable models are given as an example, and a general recipe to build infinitely many possible models is provided.Comment: Slightly revised version, 7 pages, no figures, to appear in PRA. Final version, removed extra references no longer cite

    Patterns of variability in early life traits of a Mediterranean coastal fish

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    Spawning dates and pelagic larval duration (PLD) are early life traits (ELT) crucial for understanding life cycles, properly assessing patterns of connectivity and gathering indications about patchiness or homogeneity of larval pools. Considering that little attention has been paid to spatial variability in these traits, we investigated variability of ELT from the analysis of otolith microstructure in the common two-banded sea bream Diplodus vulgaris. In the southwestern Adriatic Sea, along ~200 km of coast (∌1° in latitude, 41.2° to 40.2°N), variability of ELT was assessed at multiple spatial scales. Overall, PLD (ranging from 25 to 61 d) and spawning dates (October 2009 to February 2010) showed significant variability at small scales (i.e. <6 km), but not at larger scales. These outcomes suggest patchiness of the larval pool at small spatial scales. Multiple causal processes underlying the observed variability are discussed, along with the need to properly consider spatial variability in ELT, for example when delineating patterns of connectivity. Copyright © 2013 Inter-Research

    Recupero e consolidamento della collezione scheletrica del Museo di Zoologia “Doderlein”

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    Il presente articolo illustra un’operazione di restauro che ha aperto una fase di recupero di diversi elementi scheletrici, da tempo deteriorati, nel Museo di Zoologia “Doderlein”, oggi afferente al Sistema Museale d’Ateneo - SIMUA - dell’UniversitĂ  degli Studi di Palermo. Il lavoro si Ăš articolato in pulitura, restauro e consolidamento di cinquanta pezzi dei cinque gruppi di vertebrati. Questo intervento rappresenta solamente una piccola tessera di un progetto piĂč ampio, che ha come obiettivo finale il recupero dell’intera collezione zoologica presente in Museo.The present work took place in the Museum of Zoology “Doderlein” of the SIMUA, University of Palermo. A restoration of skeletons was performed following the main phases: cleaning, restoration and consolidation of fifty pieces of the main five vertebrate taxa. This action represents the beginning of a wider project, of which the final aim is to recover the entire zoological collection present in the Museum

    Evaluation of graft success of grapevine after incubation room by means of thermographic, electrical and mechanical techniques

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    Grafting is an important technique for getting good yields in plant multiplication. Understanding the success of the graft after the incubation stage is important to the evaluation of the suitable grafting for the open field (nursery). Successful grafting in vines requires the development of a functional vascular system between the scion and the rootstock. The graft compatibility and its augmentation depend upon various natural factors like environment, soil conditions and protective measures. The present study examines the capability of thermographic, mechanical and electrical techniques to assess the graft quality and success after the incubation stage. The trial was carried out at Vivai Mannone, (Petrosino, Western Sicily, 37\uc2\ub042'26.28''N - 12\uc2\ub029'09.57''E). After the different tests, various grafting combinations were planted in the nursery and followed for the vegetative season. Before the evaluation procedure was performed graft unions have been subjected to a moderate heating from ambient temperature, then the thermal transient toward ambient temperature was monitored by means of a thermal imaging camera. As far as the electrical testing procedure was concerned, a sinusoidal voltage was applied through the grafts-cuttings, and the voltage attenuation at different points at increasing distances from the source was measured by an oscilloscope. The mechanical strength of the graft undergoing a controlled rate flexural loading was monitored by a PC remote controlled digital dynamometer. Experimental results show that we were able to distinguish the successful grafting only with the thermographic test. Moreover, this technique was the only non-destructive test from which it was possible to derive quantitative parameters, useful to provide successful nursery forecast. Engraftment results detected at the nursery showed a 15% error in forecast based on the proposed thermal image method, which is a satisfactory value for a feasibility study

    Botanicals in Functional Foods and Food Supplements: Tradition, Efficacy and Regulatory Aspects

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    In recent decades, the interest in products containing botanicals and claiming \u201cfunctional\u201d properties has increased exponentially. Functional foods, novel foods and food supplements have a special impact on the consumers, who show significant expectation for their well-being. Food supplements with botanical ingredients are the food area that has witnessed the greatest development, in terms of the number of available products, budget, and consumer acceptability. This review refers to and discusses some open points, such as: 1) the definitions and regulation of products containing botanicals; 2) the difficulty in obtaining nutritional and functional claims (botanical ingredients obtaining claims in the EU are listed and summarized); 3) the safety aspects of these products; and 4) the poor harmonization between international legislations. The availability of these "new" products can positively influence the well-being of the population, but it is essential to provide the consumers with the necessary recommendations to guide them in their purchase and use
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