80 research outputs found

    Experimental reversion of the optimal quantum cloning and flipping processes

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    The quantum cloner machine maps an unknown arbitrary input qubit into two optimal clones and one optimal flipped qubit. By combining linear and non-linear optical methods we experimentally implement a scheme that, after the cloning transformation, restores the original input qubit in one of the output channels, by using local measurements, classical communication and feedforward. This significant teleportation-like method demonstrates how the information is preserved during the cloning process. The realization of the reversion process is expected to find useful applications in the field of modern multi-partite quantum cryptography.Comment: 10 pages, 3 figure

    Entanglement, EPR correlations and mesoscopic quantum superposition by the high-gain quantum injected parametric amplification

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    We investigate the multiparticle quantum superposition and the persistence of multipartite entanglement of the quantum superposition generated by the quantum injected high-gain optical parametric amplification of a single photon. The physical configuration based on the optimal universal quantum cloning has been adopted to investigate how the entanglement and the quantum coherence of the system persists for large values of the nonlinear parametric gain g.Comment: 9 pages, 5 figure

    Realization of a Decoherence-free, Optimally Distinguishable Mesoscopic Quantum Superposition

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    We report the realization of an entangled quantum superposition of M=12 photons by a high gain, quantum-injected optical parametric amplification. The system is found so highly resilient against decoherence to exhibit directly accessible mesoscopic interference effects at normal temperature. By modern tomographic methods the non-separability and the quantum superposition are demonstrated for the overall mesoscopic output state of the dynamic ''closed system''. The device realizes the condition conceived by Erwin Schroedinger with his 1935 paradigmatic ''Cat'' apologue, a fundamental landmark in quantum mechanics.Comment: 10 pages, 3 figure

    A multilevel carbon and water footprint dataset of food commodities

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    Informing and engaging citizens to adopt sustainable diets is a key strategy for reducing global environmental impacts of the agricultural and food sectors. In this respect, the first requisite to support citizens and actors of the food sector is to provide them a publicly available, reliable and ready to use synthesis of environmental pressures associated to food commodities. Here we introduce the SU-EATABLE LIFE database, a multilevel database of carbon (CF) and water (WF) footprint values of food commodities, based on a standardized methodology to extract information and assign optimal footprint values and uncertainties to food items, starting from peer-reviewed articles and grey literature. The database and its innovative methodological framework for uncertainty treatment and data quality assurance provides a solid basis for evaluating the impact of dietary shifts on global environmental policies, including climate mitigation through greenhouse gas emission reductions. The database ensures repeatability and further expansion, providing a reliable science-based tool for managers and researcher in the food sector

    Sviluppo di modelli innovativi per il monitoraggio multiscala degli indicatori di servizi ecosistemici nelle foreste Mediterranee (Progetto MIMOSE).

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    Gli ecosistemi, attraverso le loro funzioni, forniscono un ampio range di beni e servizi, che risultano fondamentali per il benessere dell’uomo. Questi vengono complessivamente definiti Servizi Ecosistemici (SE). I SE possono essere intesi come un flusso di valori verso la società, quale risultato dello stato e della quantità del capitale naturale disponibile. Il mantenimento degli stocks del capitale naturale può permettere di prevedere i flussi futuri dei SE, assicurando quindi il benessere dell’uomo per le generazioni future. Il progetto FIRB 2012 MIMOSE è finalizzato allo sviluppo di un approccio multiscala innovativo e all’implementazione di strumenti previsionali volti al monitoraggio dei SE in habitat forestali Mediterranei. Un set di indicatori viene considerato per stimare i SE forniti dalle foreste, sviluppando strumenti integrati per il loro monitoraggio multiscala. Le attività di ricerca vertono allo sviluppo di un metodo statistico innovativo per la stima spaziale degli indicatori di SE, sulla base di dati disponibili a diversi livelli di scala spaziale. Sono realizzate mappe wall-to-wall per la fornitura dei SE, derivate da diversi domini spaziali, dal livello di scala locale sino ad aree forestali di grande estensione. I dati sugli indicatori dei SE sono forniti nel contesto di attività di campionamento già stabilite (raccolta dati a livello di aree di saggio e di popolamento), per poi applicare tecniche di spazializzazione per aggregare i dati raccolti su scala locale a livelli di scala più ampia (paesaggio, scala regionale); l’approccio utilizzato viene valutato attraverso l’applicazione di strumenti di monitoraggio in un set di aree test. Si procede quindi alla valutazione dei cambiamenti spazio-temporali nella previsione dei SE, considerando indicatori sensibili alla gestione forestale, ovvero capaci di evidenziare cambiamenti nella previsione di fornitura di beni e servizi ad opera dei sistemi forestali, in relazione a differenti scenari gestionali, con l’obiettivo di fornire indicazioni ai gestori forestali ed alle comunità locali per l’applicazione di pratiche di gestione che possano mantenere o incrementare la fornitura dei SE in un preciso contesto territoriale. Questo progetto permette di realizzare un’attenta analisi dei gaps esistenti negli attuali schemi di inventariazione in relazione alla fornitura dei SE, con l’obiettivo di dare indicazioni utili all’implementazione ed integrazione degli stessi mediante individuazione di nuovi indicatori, nell’ottica di una gestione forestale sostenibile. Le attività di ricerca in corso possono concretamente contribuire all’incorporazione dei SE nei processi decisionali connessi alla gestione dei paesaggi forestali, fornendo un’opportunità per comprendere la congruenza tra i diversi SE negli ambienti forestali

    Value-Chain Wide Food Waste Management: A Systematic Literature Review

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    © 2019, Springer Nature Switzerland AG. The agriculture value chain, from farm to fork, has received enormous attention because of its key role in achieving United Nations Global Challenges Goals. Food waste occurs in many different forms and at all stages of the food value chain, it has become a worldwide issue that requires urgent actions. However, the management of food waste has been traditionally segmented and in an isolated manner. This paper reviews existing work that has been done on food waste management in literature by taking a holistic approach, in order to identify the causes of food waste, food waste prevention strategies, and elicit recommendations for future work. A five step systematic literature review has been adopted for a thorough examination of the existing research on the topic and new insights have been obtained. The findings suggest that the main sources of food waste include food overproduction and surplus, food waste caused by processing, logistical inconsistencies, and households. Main food waste prevention strategies have been revealed in this paper include policy solutions, packaging solutions, date-labelling solutions, logistics solutions, changing consumers’ behaviours, and reuse and redistribution solutions. Future research directions such as using value chain models to reduce food waste and forecasting food waste have been identified in this paper. This study makes a contribution to the extant literature in the field of food waste management by discovering main causes of food waste in the value chain and eliciting prevention strategies that can be used to reduce/eliminate relevant food waste

    Vocal Communications and the Maintenance of Population Specific Songs in a Contact Zone

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    Bird song has been hypothesized to play a role in several important aspects of the biology of songbirds, including the generation of taxonomic diversity by speciation; however, the role that song plays in speciation within this group may be dependent upon the ability of populations to maintain population specific songs or calls in the face of gene flow and external cultural influences. Here, in an exploratory study, we construct a spatially explicit model of population movement to examine the consequences of secondary contact of populations singing distinct songs. We concentrate on two broad questions: 1) will population specific songs be maintained in a contact zone or will they be replaced by shared song, and 2) what spatial patterns in the distribution of songs may result from contact? We examine the effects of multiple factors including song-based mating preferences and movement probabilities, oblique versus paternal learning of song, and both cultural and genetic mutations. We find a variety of conditions under which population specific songs can be maintained, particularly when females have preferences for their population specific songs, and we document many distinct patterns of song distribution within the contact zone, including clines, banding, and mosaics

    Introgression and rapid species turnover in sympatric damselflies

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    <p>Abstract</p> <p>Background</p> <p>Studying contemporary hybridization increases our understanding of introgression, adaptation and, ultimately, speciation. The sister species <it>Ischnura elegans </it>and <it>I. graellsii </it>(Odonata: Coenagrionidae) are ecologically, morphologically and genetically similar and hybridize. Recently, <it>I. elegans </it>has colonized northern Spain, creating a broad sympatric region with <it>I. graellsii</it>. Here, we review the distribution of both species in Iberia and evaluate the degree of introgression of <it>I. graellsii </it>into <it>I. elegans </it>using six microsatellite markers (442 individuals from 26 populations) and five mitochondrial genes in sympatric and allopatric localities. Furthermore, we quantify the effect of hybridization on the frequencies of the genetically controlled colour polymorphism in females of both species.</p> <p>Results</p> <p>In a principal component analysis of the microsatellite data, the first two principal components summarised almost half (41%) of the total genetic variation. The first axis revealed a clear separation of <it>I. graellsii </it>and <it>I</it>. <it>elegans </it>populations, while the second axis separated <it>I. elegans </it>populations. Admixture analyses showed extensive hybridization and introgression in <it>I. elegans </it>populations, consistent with <it>I. elegans </it>backcrosses and occasional F<sub>1</sub>-hybrids, suggesting hybridization is on-going. More specifically, approximately 58% of the 166 Spanish <it>I. elegans </it>individuals were assigned to the <it>I. elegans </it>backcross category, whereas not a single of those individuals was assigned to the backcross with <it>I. graellsii</it>. The mitochondrial genes held little genetic variation, and the most common haplotype was shared by the two species.</p> <p>Conclusions</p> <p>The results suggest rapid species turnover in sympatric regions in favour of <it>I. elegans</it>, corroborating previous findings that <it>I. graellsii </it>suffers a mating disadvantage in sympatry with <it>I. elegans</it>. Examination of morph frequency dynamics indicates that hybridization is likely to have important implications for the maintenance of multiple female morphs, in particular during the initial period of hybridization.</p

    Ecological character displacement in the face of gene flow: Evidence from two species of nightingales

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    <p>Abstract</p> <p>Background</p> <p>Ecological character displacement is a process of phenotypic differentiation of sympatric populations caused by interspecific competition. Such differentiation could facilitate speciation by enhancing reproductive isolation between incipient species, although empirical evidence for it at early stages of divergence when gene flow still occurs between the species is relatively scarce. Here we studied patterns of morphological variation in sympatric and allopatric populations of two hybridizing species of birds, the Common Nightingale (<it>Luscinia megarhynchos</it>) and the Thrush Nightingale (<it>L. luscinia</it>).</p> <p>Results</p> <p>We conducted principal component (PC) analysis of morphological traits and found that nightingale species converged in overall body size (PC1) and diverged in relative bill size (PC3) in sympatry. Closer analysis of morphological variation along geographical gradients revealed that the convergence in body size can be attributed largely to increasing body size with increasing latitude, a phenomenon known as Bergmann's rule. In contrast, interspecific interactions contributed significantly to the observed divergence in relative bill size, even after controlling for the effects of geographical gradients. We suggest that the divergence in bill size most likely reflects segregation of feeding niches between the species in sympatry.</p> <p>Conclusions</p> <p>Our results suggest that interspecific competition for food resources can drive species divergence even in the face of ongoing hybridization. Such divergence may enhance reproductive isolation between the species and thus contribute to speciation.</p
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