Visible quantum plasmonics from metallic nanodimers

We report theoretical evidence that bulk nonlinear materials weakly interacting with highly localized plasmonic modes in ultra-sub-wavelength metallic nanostructures can lead to nonlinear effects at the single plasmon level in the visible range. In particular, the two-plasmon interaction energy in such systems is numerically estimated to be comparable with the typical plasmon linewidths. Localized surface plasmons are thus predicted to exhibit a purely nonclassical behavior, which can be clearly identified by a sub-Poissonian second-order correlation in the signal scattered from the quantized plasmonic field under coherent electromagnetic excitation. We explicitly show that systems sensitive to single-plasmon scattering can be experimentally realized by combining electromagnetic confinement in the interstitial region of gold nanodimers with local infiltration or deposition of ordinary nonlinear materials. We also propose configurations that could allow to realistically detect such an effect with state-of-the-art technology, overcoming the limitations imposed by the short plasmonic lifetime

An EST database from saffron stigmas

BACKGROUND: Saffron (Crocus sativus L., Iridaceae) flowers have been used as a spice and medicinal plant ever since the Greek-Minoan civilization. The edible part - the stigmas - are commonly considered the most expensive spice in the world and are the site of a peculiar secondary metabolism, responsible for the characteristic color and flavor of saffron. RESULTS: We produced 6,603 high quality Expressed Sequence Tags (ESTs) from a saffron stigma cDNA library. This collection is accessible and searchable through the Saffron Genes database http://www.saffrongenes.org. The ESTs have been grouped into 1,893 Clusters, each corresponding to a different expressed gene, and annotated. The complete set of raw EST sequences, as well as of their electopherograms, are maintained in the database, allowing users to investigate sequence qualities and EST structural features (vector contamination, repeat regions). The saffron stigma transcriptome contains a series of interesting sequences (putative sex determination genes, lipid and carotenoid metabolism enzymes, transcription factors). CONCLUSION: The Saffron Genes database represents the first reference collection for the genomics of Iridaceae, for the molecular biology of stigma biogenesis, as well as for the metabolic pathways underlying saffron secondary metabolism

Automatic Passenger Counting on the Edge via Unsupervised Clustering

We present a device- and network-based solution for automatic passnger counting that operates on the edge in real time. The proposed solution consists of a low-cost WiFi scanner device equipped with custom algorithms for dealing with MAC address randomization. Our low-cost scanner is able to capture and analyze 802.11 probe requests emitted by passengers' devices such as laptops, smartphones, and tablets. The device is configured with a Python data-processing pipeline that combines data coming from different types of sensors and processes them on the fly. For the analysis task, we have devised a lightweight version of the DBSCAN algorithm. Our software artifact is designed in a modular way in order to accommodate possible extensions of the pipeline, e.g., either additional filters or data sources. Furthermore, we exploit multi-threading and multi-processing for speeding up the entire computation. The proposed solution has been tested with different types of mobile devices, obtaining promising experimental results. In this paper, we present the key ingredients of our edge computing solution

Optimal Management of a Smart Port with Shore-Connection and Hydrogen Supplying by Stochastic Model Predictive Control

The paper proposes an optimal management strategy for a Smart Port equipped with renewable generation and composed by an electrified quay, operating Cold-Ironing, and a Hydrogen-based quay, supplying Zero-Emission Ships. One Battery Energy Storage System and one Hydrogen Energy Storage System are used to manage renewable energy sources and to supply electric and hydrogen-fueled ships. A model predictive control based algorithm is designed to define the best economic strategy to be followed during operations. The control algorithm takes into account the uncertainties of renewable energy generation using stochastic optimization. The performance of the approach is tested on a potential future Smart Port equipped with wind and photovoltaic generation

Admixture between ancient lineages, selection, and the formation of sympatric stickleback species-pairs

Ecological speciation has become a popular model for the development and maintenance of reproductive isolation in closely related sympatric pairs of species or ecotypes. An implicit assumption has been that such pairs originate (possibly with gene flow) from a recent, genetically homogeneous ancestor. However, recent genomic data have revealed that currently sympatric taxa are often a result of secondary contact between ancestrally allopatric lineages. This has sparked an interest in the importance of initial hybridization upon secondary contact, with genomic reanalysis of classic examples of ecological speciation often implicating admixture in speciation. We describe a novel occurrence of unusually well-developed reproductive isolation in a model system for ecological speciation: the three-spined stickleback (Gasterosteus aculeatus), breeding sympatrically in multiple lagoons on the Scottish island of North Uist. Using morphological data, targeted genotyping, and genome-wide single-nucleotide polymorphism data, we show that lagoon resident and anadromous ecotypes are strongly reproductively isolated with an estimated hybridization rate of only ∼1%. We use palaeoecological and genetic data to test three hypotheses to explain the existence of these species-pairs. Our results suggest that recent, purely ecological speciation from a genetically homogeneous ancestor is probably not solely responsible for the evolution of species-pairs. Instead, we reveal a complex colonization history with multiple ancestral lineages contributing to the genetic composition of species-pairs, alongside strong disruptive selection. Our results imply a role for admixture upon secondary contact and are consistent with the recent suggestion that the genomic underpinning of ecological speciation often has an older, allopatric origin

Disclosing the composition of the Renaissance thin uniface metallic strikings by Alessandro Cesati (mid-16th century) from the Bargello Museum using non-invasive analyses

This study focuses on a series of thin uniface strikings preserved in the Bargello Museum (Florence, Italy), analysed using non-destructive and non-invasive techniques. These specimens were created in Rome by Italo-Greek sixteenth-century goldsmith and medalist Alessandro Cesati, called ‘Grechetto’, for Pope Paul III (1534–1549 A.D.) and Pope Julius III (1550–1555 A.D.). The samples were studied to explore the chemical composition and the surface morphology of the alloy since they are characterized by thin metal uniface strikings, representing a truly unique case study. New information about production technique, alloy composition, and on the use of these foils as prototypes by the artist are gained thanks to the analysis of such exemplars. A scanning electron microscope with an energy dispersive system (SEM-EDS) shows that the pieces are characterized by a surface enriched in Ag (up to 48 wt%) and/or Au (up to 6.3 wt%), whereas the back side shows an Sn-Pb alloy. In this specimen, Sn reaches 59.9 wt%, and Pb is up to 64.3 wt%, displaying a typical microstructure of Pb islands dispersed in an Sn matrix. Moreover, the absence of a preferential orientation of such lead clusters implies that the medal was subjected to very soft mechanical processing, such as hammering. FTIR analysis detected the use of a resin to glue the foils onto a different substrate, suggesting that Cesati also used these strikings to produce medallic prototypes to send to friends and patrons outside Rome

The 2009 L'Aquila Earthquake: Postseismic Deformation with High Temporal Resolution Using the new GPS "Carrier Range" Data Type

The availability of continuous GPS measurements during or soon after significant (Mw > 6) seismic events is important to record the coseismic displacements, the initial postseismic evolution and to evaluate their relative contribution to the overall crustal deformation and total moment release (both seismic and aseismic). Here we present the result of the analysis of continuously operating GPS permanent stations already active or rapidly deployed after the Mw 6.3 2009 April 6th L'Aquila earthquake. In contrast to the observations made for previous earthquakes in Italy, our observations capture the 2009 mainshock allowing an improved temporal resolution on the early postseismic deformation. In order to better define initial postseismic displacements and investigate sub-daily station motions we calculate epoch-by-epoch (0.1 - 30 sec) position time series with the new "carrier range" data type based on the JPL GIPSY-OASIS package. This new approach is based on the calibration of carrier phase data of each station using estimates of one-way carrier phase biases from an ambiguity-fixed network of ~3,500 stations worldwide [see Blewitt, Bertiger and Weiss, 2009 Fall AGU Meeting]. Carrier range data (a precise pseudorange data type) were constructed for GPS stations in the epicentral area, and were processed without carrier phase bias estimation. Time-dependent postseismic displacements were then modeled with a logarithmic time-dependent function. Since postseismic deformation begins immediately after the mainshock and is large within the first day following the mainshock, the actual estimate of amount of coseismic deformation depends upon the temporal character of the deformation and the availability of high-rate GPS time series immediately after the mainshock. The results of our analysis are then used to characterize the characteristics of the initial postseismic evolution after the 2009 mainshock and to investigate the time-dependent distribution of afterslip on the fault