Different invasibility of permanent and temporary waterbodies in a semiarid Mediterranean Island

Nonindigenous species (NIS) represent a threat to aquatic biodiversity worldwide. However, freshwater ecosystems in drylands are potentially more prone to biological invasions than those located in temperate regions because of the higher number of artificial waterbodies generally occurring in these areas, which might act as invasion hubs for NIS. We review the available information about NIS in Sicilian waterbodies, discuss the role exerted by artificial lakes and ponds in facilitating the establishment of NIS in arid and semiarid areas, and compare the invasibility of permanent and temporary waterbodies in drylands. Artificial waterbodies increase the target-area effect for dispersers and provide a hospitable environment for NIS because of their recent origin and the lack of efficient biological filters against newcomers, thus acting as bridgeheads and invasion hubs favouring invasive species. Finally, we propose actions to attenuate the threats caused by NIS to the sensitive native biota of aquatic ecosystems in drylands

Occurrence, distribution and bibliography of the medicinal leech Hirudo verbana Carena, 1820 (Hirudinea, Hirudinidae) in Sicily (Italy)

The occurrence of the medicinal leech Hirudo verbana in the inland waters of Sicily has been lately overlooked. In the present note, the occurrence and distribution of this species is reviewed based both on the review of the available literature data and field collecting. Although a noteworthy reduction in the distribution range of the species seems to have taken place in Sicily in the course of the XX century, Hirudo verbana was confirmed to be still present in several sites located both within and out of Natura2000 sites. The Sicilian populations of the species should be included in the frame of the monitoring activities established by the Article 17 of the EU Council Directive 92/43/EEC (“Habitats Directive”)

Neutrino mass hierarchy and precision physics with medium-baseline reactors: Impact of energy-scale and flux-shape uncertainties

Nuclear reactors provide intense sources of electron antineutrinos, characterized by few-MeV energy E and unoscillated spectral shape Phi(E). High-statistics observations of reactor neutrino oscillations over medium-baseline distances L ~ O(50) km would provide unprecedented opportunities to probe both the long-wavelength mass-mixing parameters (delta m^2 and theta_12) and the short-wavelength ones (Delta m^2 and theta_13), together with the subtle interference effects associated with the neutrino mass hierarchy (either normal or inverted). In a given experimental setting - here taken as in the JUNO project for definiteness - the achievable hierarchy sensitivity and parameter accuracy depend not only on the accumulated statistics but also on systematic uncertainties, which include (but are not limited to) the mass-mixing priors and the normalizations of signals and backgrounds. We examine, in addition, the effect of introducing smooth deformations of the detector energy scale, E -> E'(E), and of the reactor flux shape, Phi(E) -> Phi'(E), within reasonable error bands inspired by state-of-the-art estimates. It turns out that energy-scale and flux-shape systematics can noticeably affect the performance of a JUNO-like experiment, both on the hierarchy discrimination and on precision oscillation physics. It is shown that a significant reduction of the assumed energy-scale and flux-shape uncertainties (by, say, a factor of 2) would be highly beneficial to the physics program of medium-baseline reactor projects. Our results also shed some light on the role of the inverse-beta decay threshold, of geoneutrino backgrounds, and of matter effects in the analysis of future reactor oscillation data.Comment: 13 pages, including 17 figures. Minor changes in the text, references added. To appear in Phys. Rev.

Neutrino masses and mixings: Status of known and unknown 3ν3\nu parameters

Within the standard 3nu mass-mixing framework, we present an up-to-date global analysis of neutrino oscillation data (as of January 2016), including the latest available results from experiments with atmospheric neutrinos (Super-Kamiokande and IceCube DeepCore), at accelerators (first T2K anti-nu and NOvA nu runs in both appearance and disappearance mode), and at short-baseline reactors (Daya Bay and RENO far/near spectral ratios), as well as a reanalysis of older KamLAND data in the light of the "bump" feature recently observed in reactor spectra. We discuss improved constraints on the five known oscillation parameters (delta m^2, |Delta m^2|, sin^2theta_12, sin^2theta_13, sin^2theta_23), and the status of the three remaining unknown parameters: the mass hierarchy, the theta_23 octant, and the possible CP-violating phase delta. With respect to previous global fits, we find that the reanalysis of KamLAND data induces a slight decrease of both delta m^2 and sin^2theta_12, while the latest accelerator and atmospheric data induce a slight increase of |Delta m^2|. Concerning the unknown parameters, we confirm the previous intriguing preference for negative values of sin(delta) [with best-fit values around sin(delta) ~ -0.9], but we find no statistically significant indication about the theta_23 octant or the mass hierarchy (normal or inverted). Assuming an alternative (so-called LEM) analysis of NOvA data, some delta ranges can be excluded at >3 sigma, and the normal mass hierarchy appears to be slightly favored at 90% C.L. We also describe in detail the covariances of selected pairs of oscillation parameters. Finally, we briefly discuss the implications of the above results on the three non-oscillation observables sensitive to the (unknown) absolute nu mass scale: the sum of nu masses, the effective nu_e mass, and the effective Majorana mass.Comment: 15 pages, 9 figures, 2 tables. Invited contribution prepared for the Nuclear Physics B Special Issue on "Neutrino Oscillations" celebrating the Nobel Prize in Physics 201

An annotated checklist and bibliography of the diaptomidae (copepoda, calanoida) of Italy, Corsica, and the maltese islands

Calanoids of the family Diaptomidae are the most widespread copepods in the lentic inland waters of the Palearctic region. In Italy, studies on the family date back to the end of 19th century. Since then, several papers contributed to increase the knowledge on their presence, distribution, and ecological preferences. Nevertheless, new records for the area and the discovery of putative new species stress that the current knowledge on these inland water crustaceans is still far from being exhaustive. This paper presents an updated and annotated checklist and bibliography of the Diaptomidae of the Italian peninsula and surrounding islands, including Corsica and the Maltese islands, compiled through a critical review of the existing literature and carrying out further field research. The doubtful records reported in the literature are discussed and clarified. The updated checklist includes 30 diaptomid species and subspecies; among them, an alien species and three putative new species pending formal description are reported. About 20% of the observed species are endemic or subendemic to the study area. The faunal provinces ascribed to the Mediterranean limnofaunistic region host the highest species richness and contribute to the checklist with rare species and unique occurrences. The high species richness observed in the Mediterranean area supports the hypothesis of a long-lasting persistence of an ancient and peculiar copepod fauna

Status of three-neutrino oscillation parameters, circa 2013

The standard three-neutrino (3nu) oscillation framework is being increasingly refined by results coming from different sets of experiments, using neutrinos from solar, atmospheric, accelerator and reactor sources. At present, each of the known oscillation parameters [the two squared mass gaps (delta m^2, Delta m^2) and the three mixing angles (theta_12}, theta_13, theta_23)] is dominantly determined by a single class of experiments. Conversely, the unknown parameters [the mass hierarchy, the theta_23 octant and the CP-violating phase delta] can be currently constrained only through a combined analysis of various (eventually all) classes of experiments. In the light of recent new results coming from reactor and accelerator experiments, and of their interplay with solar and atmospheric data, we update the estimated N-sigma ranges of the known 3nu parameters, and revisit the status of the unknown ones. Concerning the hierarchy, no significant difference emerges between normal and inverted mass ordering. A slight overall preference is found for theta_23 in the first octant and for nonzero CP violation with sin delta < 0; however, for both parameters, such preference exceeds 1 sigma only for normal hierarchy. We also discuss the correlations and stability of the oscillation parameters within different combinations of data sets.Comment: Updated and revised version, accepted for publication in PRD. The analysis includes the latest (March 2014) T2K disappearance data: all the figures and the numerical results have been updated, and parts of the text have been revised accordingl

Conferma della presenza di Aphanius fasciatus (Valenciennes, 1821) (Cyprinodontiformes Cyprinodontidae) nel bacino idrografico del Fiume Imera Meridionale (Sicilia)

Un\u2019abbondante popolazione del Ciprinodontide autoctono Aphanius fasciatus \ue8 stata rinvenuta nel Fiume ImeraMeridionale ed in alcuni suoi affluenti. \uc9 cos\uec confermata la persistenza della specie nel sito, nonostante le pesanti alterazioni ambientali che hanno interessato il fiume e che avevano fatto ritenere A. fasciatus localmente estinto. Trattandosi di una delle poche popolazioni di Aphanius fasciatus sopravvissute nei corsi d\u2019acqua siciliani e alla luce della notevole diversit\ue0 genetica e morfologica riscontrata tra le differenti popolazioni siciliane di questo Ciprinodontide, la sopravvivenza di questa popolazione assume un\u2019importante valenza conservazionistica

Dal quadro al modello virtuale: una ricostruzione tridimensionale interattiva dell'Albergheria di Palermo nel 1749

This study suggests a virtual three-dimensional reconstruction of a large urban portion of Palermo Historical Centre modelled on an isometrical view of the 17th century entitled Descrizzione del distretto parrocchiale dell’Albergheria fatta l’anno 1749. It is a painting on canvas that has been kept inside the parish of S.Nicolò all’Albergheria, and which in latter days has been taken by the Museum of Palermo Diocese where it is presently exposed to the public. The work presents different levels of interest for the reading of urban ancient morphology which now has disappeared and for the right information of road textures, blocks and monuments represented there. The digital elaboration that has been made has been overlayed to a second three-dimensional model that has been got from the present maps of Palermo Historical Centre which describe the present configuration of the quarter: thus the model which derives from the 17th century representation has been referred to the real quotes of the ground and to the elevations of the existing buildings which are illustrated and described in the picture. Then all the proposed material has been used to make a new reading of the work and to propose its transformation in a “visual hypertext”. All the elements of the picture have been “translated” as file folders, links about the town history and of its monuments, either disappeared or still existing

On the occurrence of Metadiaptomus chevreuxi (Calanoida, Diaptomidae, Paradiaptominae) in the Iberian Peninsula, with notes on the ecology and distribution of its European populations

Temporary ponds are one of the most peculiar ecosystems in the world, being characterized by an extraordinarily rich crustacean fauna, with a high degree of endemism. Among them, diaptomid copepods are among the most biogeographically interesting taxa. However, the present knowledge on diaptomid distribution is still far from being exhaustive, even in the relatively well-studied western European countries. In this study, we report the first record of the diaptomid calanoid copepod Metadiaptomus chevreuxi for the Iberian Peninsula, where it was collected in five temporary ponds in Andalusia (Spain). The characteristics of the new sites are described, the literature dealing with the European localities of the species is reviewed, and a molecular phylogenetic tree has been built, based on new and previously available mitochondrial DNA sequences, thus expanding the knowledge on the ecology and phylogeography of this rare species. The species mainly occupies small isolated temporary ponds in (semi-)arid regions, suggesting adaptations to unpredictable aquatic habitats. The existence of two molecular clades separating the Iberian from the Sicilian and Tunisian populations supports the existence of a longitudinal long-term disjunction, whereas the north-south flow is probably facilitated by migrating birds. Further research on the biota of the small water bodies of the western Mediterranean area may help to expand our knowledge on rare aquatic species, such as M. chevreuxi, and to better interpret their natural history