A cryptic alien seaweed spreading in Mediterranean coastal lagoons.

1 - Introductions of exotic macroalgae have increased recently on European shores. Each introductioninvolves at least one vector of transfer. For macroalgae, the potential vectors are aquaculture(intentional or accidental introduction), fouling on hulls, ballast water, aquarium trading, fishingnets.2 - Coastal lagoons, including Venice and Thau Lagoon, developed into major hotspots of marinemacrophyte introductions in the Mediterranean Sea. Moreover, in shallow lagoons and estuaries,eutrophication processes have resulted in the development of macroalgal biomass.3 - The most characteristic species of these macroalgal communities include members of the ulvophyceangenus Ulva L. In foliose Ulvales, simple morphology and anatomy, rampant convergence, remarkabledegrees of phenotypic plasticity in response to environmental factors tend to confound attempts atidentification and make cryptic introduction difficult to detect.4 - During a survey of macroalgal biodiversity in Venice Lagoon, among the pool of exotic speciesfound, there was an Ulva differing from the Atlantic and Mediterranean species in both vegetativeand reproductive features. Detailed observations consented us to identify the taxon as Ulva pertusaKjellman, previously reported in the Mediterranean only for Thau Lagoon

Identifying alien macroalgae through DNA barcoding: the case of Hypnea cornuta (Cystocloniaceae, Rhodophyta)

1 - Introduction of non-indigenous macroalgae has become a major topic in the last decades. Potential vectors are aquaculture, fouling on hulls, ballast water, aquarium trading, fishing nets.2 - Within a program of census of macroalgal alien species through DNA barcoding we found a population of previously unreported rhodophyte in Cape Peloro Lagoon and nearby marine coasts (north-eastern Sicily, Italy).3 - All collected individuals were identified as the alien species Hypnea cornuta based on morphological characters confirmed by the analysis of COI-5’ sequences

Characterization of dyes extracted from Antarctic red algae for their use in DSSC

En este trabajo se realizó la extracción en medio acuoso de ficoeritrina proveniente de algas rojas de la Isla Rey Jorge. Las especies que mostraron mejores rendimientos de extracción fueron Palmaria decipiens y Delesseria lancifolia. Esta ficoeritrina mostró un comportamiento adecuado para su uso como sensibilizador en celdas de tipo DSSC (dye sensitized solar cells), con altos valores de absorbancia, buena estabilidad con la temperatura y adecuado potencial redox.In this work, the extraction of phycoerythrin of red algae from King George’s Island was performed in aqueous media. Among analyzed, best extraction yields were obtained from Palmaria decipiens and Delesseria lancifolia. This phycoerythrin showed adequate characteristics to be used as sensitizer in DSSC (dye sensitized solar cells).with high absorbance values, good stability towards temperature and a satisfactory redox potential value

Current status and trends of biological invasions in the Lagoon of Venice, a hotspot of marine NIS introductions in the Mediterranean Sea

This paper provides an updated account of the occurrence and abundance of non-indigenous species (NIS) in an area of high risk of introduction: the Lagoon of Venice (Italy). This site is a known hotspot of NIS introductions within the Mediterranean Sea, hosting all the most important vectors of introduction of marine NIS—shipping, recreational boating, shellfish culture and live seafood trade. The recent literature demonstrates that the number of NIS in Venice is continuously changing, because new species are being introduced or identified, and new evidence shows either an exotic origin of species previously believed to be native, or a native origin of formerly believed ‘‘aliens’’, or demonstrates the cryptogenic nature of others. The number of NIS introduced in the Venetian lagoon currently totals 71, out of which 55 are established. This number exceeds those displayed by some nations like Finland, Portugal or Libya. Macroalgae are the taxonomic group with the highest number of introduced species (41 % of NIS): the most likely vector for their introduction is shellfish culture. The source region of NIS introduced to Venice is mainly represented by other Mediterranean or European sites (76 %). The Lagoon of Venice represents a sink but also a source of NIS in the Mediterranean Sea, as it is the site of first record of several NIS, which have since further spread elsewhere.This paper provides an updated account of the occurrence and abundance of non-indigenous species (NIS) in an area of high risk of introduction: the Lagoon of Venice (Italy). This site is a known hotspot of NIS introductions within the Mediterranean Sea, hosting all the most important vectors of introduction of marine NIS-shipping, recreational boating, shellfish culture and live seafood trade. The recent literature demonstrates that the number of NIS in Venice is continuously changing, because new species are being introduced or identified, and new evidence shows either an exotic origin of species previously believed to be native, or a native origin of formerly believed "aliens", or demonstrates the cryptogenic nature of others. The number of NIS introduced in the Venetian lagoon currently totals 71, out of which 55 are established. This number exceeds those displayed by some nations like Finland, Portugal or Libya. Macroalgae are the taxonomic group with the highest number of introduced species (41 % of NIS): the most likely vector for their introduction is shellfish culture. The source region of NIS introduced to Venice is mainly represented by other Mediterranean or European sites (76 %). The Lagoon of Venice represents a sink but also a source of NIS in the Mediterranean Sea, as it is the site of first record of several NIS, which have since further spread elsewhere

Specie esotiche invasive di rilevanza unionale in Italia: aggiornamenti e integrazioni

La Commissione Europea (CE) ha inserito ad oggi 36 taxa esotici vegetali nella lista delle specie esotiche invasive di rilevanza unionale ai sensi del Regolamento (UE) n. 1143/2014 del Parlamento Europeo e del Consiglio, recante disposizioni volte a prevenire e gestire l’introduzione e la diffusione delle specie esotiche invasive. La lista delle specie di rilevanza unionale viene periodicamente aggiornata e include quelle specie che rappresentano una grave minaccia per la biodiversità, ma anche per la salute dei cittadini e le attività economiche nei territori dell’Unione Europea e che necessitano di una gestione concertata a livello comunitario. La CE vigila sullo stato di ogni taxon grazie anche a periodiche rendicontazioni da parte dei paesi dell'Unione. In vista di tali report, tra il 2020 e il 2021 è stata definita e integrata la distribuzione di queste specie in Italia

Characterisation of silicon photomultipliers coupled to inorganic scintillating crystals for timing applications

Silicon Photo multipliers (SiPM) are solid-state photo detectors made of a matrix of Avalanche Photodiodes working in Geiger mode (GM-APD). Each APD behaves as a binary device, giving in output a standardised signal if fired by one or more photons. However, the device as a whole is an analog device, giving in output a pulse proportional to the number of incident photons. For this reason, the SiPM can be considered as a solid-state equivalent of the traditional Photomultiplier Tube (PMT), with the advantage of single photon counting capability, improved detection efficiency at wavelengths that better suit scintillating crystals' output and of compactness, ruggedness as well as easier production technology. Moreover, being a solid state device, the SiPM is also insensitive to magnetic fields and characterised by an intrinsic timing resolution which makes it a good candidate for fast timing applications. The motivation behind this thesis is the study of a system made of inorganic scintillating crystals readout by various types of SiPMs with specific interest in timing applications. The characterisation of various SiPMs with different total area and pixel sizes is discussed. The main result of this analysis is the measurement of the parameters of these photo detectors that allows the simulation of their output pulses, which ultimately determine the single photon response and hence the intrinsic performance limit of the device. In particular, it was found that coherent light improves the timing performances of SiP Ms, due to an improvement in signal to noise ratio, while almost maintaining the single photon response. For this reason, the Intrinsic and Coincidence Time Resolution (ITR and CTR respectively), i.e. the variance on the time the detector takes to respond to a light stimulus and the uncertainty introduced in the measurement of the time coincidence, were measured using a femtosecond laser. For both quantities, values ofthe order of tens of ps were found optimising the parameters of a low pass Butterworth filter and of a time stamp pick-up algorithm which is the digital equivalent of a Constant Fraction Discriminator, for two Hamamatsu MPPCs with different total area and same pixel size. Finally the characterisation of various size LYSO crystals readout by SiPMs is also reported. This study gives information on the timing and energy properties of a Gamma sensitive system and allows the understanding of the characteristics that the optimum scintillating crystal readout by SiPMs should have to optimise the coincidence time and energy resolution. Values of the CTR for a system made of two LYSO crystals with size 3 x 3 x 10 mm ' readout by a pair of MPPCs with 25 uu: pixel size and 3 x 3 mm'' total area, were found of the order of 300 ps. Hence, this detector system appears as a good candidate for timing applications involving the detection of coincident gamma rays, particularly in applications like the Time-of- Flight Positron Emission Tomography, where an excellent timing resolution imply very good spatial resolution and hence superior quality of the final image.EThOS - Electronic Theses Online ServiceGBUnited Kingdo