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”)

Size bias and differential lensing of strongly lensed, dusty galaxies identified in wide-field surveys

We address two selection effects that operate on samples of gravitationally lensed dusty galaxies identified in millimeter- and submillimeter-wavelength surveys. First, we point out the existence of a "size bias" in such samples: due to finite source effects, sources with higher observed fluxes are increasingly biased towards more compact objects. Second, we examine the effect of differential lensing in individual lens systems by modeling each source as a compact core embedded in an extended diffuse halo. Considering the ratio of magnifications in these two components, we find that at high overall magnifications the compact component is amplified by a much larger factor than the diffuse component, but at intermediate magnifications (~10) the probability of a larger magnification for the extended region is higher. Lens models determined from multi-frequency resolved imaging data are crucial to correct for this effect.Comment: 7 pages, 6 figure

Atmospheric, Solar, and CHOOZ neutrinos: a global three generation analysis

We perform a global three generation analysis of the current solar and atmospheric evidence in favor of neutrino oscillations. We also include the negative results coming from CHOOZ to constrain the nu_e mixing. We study the zones of mass-mixing oscillations parameters compatible with all the data. It is shown that almost pure nu_mu nu_tau oscillations are required to explain the atmospheric neutrino anomaly and almost pure nu_1 nu_2 oscillations to account for the solar neutrino deficit.Comment: 4 pages, talk given at 36th Rencontres de Moriond: Electroweak Interactions and Unified Theories, Les Arcs, France, 10-17 Mar 200

Zenith distribution of atmospheric neutrino events and electron neutrino mixing

Assuming atmospheric neutrino oscillations with dominant nu_munu_tau transitions, we discuss how subdominant nu_e mixing (within the Chooz reactor bounds) can alter the zenith distributions of neutrino-induced electrons and muons. We isolate two peculiar distortion effects, one mainly related to nu_e mixing in vacuum and the other to matter oscillations, that may be sufficiently large to be detected by the SuperKamiokande atmospheric nu experiment. These effects (absent for pure two-flavor nu_munu_tau transitions) do not vanish in the limit of energy-averaged oscillations.Comment: 6 pages, RevTeX, no figure

Far Infrared Variability of Sagittarius A*: 25.5 Hours of Monitoring with HerschelHerschel

Variable emission from Sgr~A*, the luminous counterpart to the super-massive black hole at the center of our Galaxy, arises from the innermost portions of the accretion flow. Better characterization of the variability is important for constraining models of the low-luminosity accretion mode powering Sgr~A*, and could further our ability to use variable emission as a probe of the strong gravitational potential in the vicinity of the $4\times10^{6}\mathrm{M}_{\odot}$ black hole. We use the \textit{Herschel} Spectral and Photometric Imaging Receiver (SPIRE) to monitor Sgr~A* at wavelengths that are difficult or impossible to observe from the ground. We find highly significant variations at 0.25, 0.35, and 0.5 mm, with temporal structure that is highly correlated across these wavelengths. While the variations correspond to $<$1% changes in the total intensity in the \textit{Herschel} beam containing Sgr~A*, comparison to independent, simultaneous observations at 0.85 mm strongly supports the reality of the variations. The lowest point in the light curves, $\sim$0.5 Jy below the time-averaged flux density, places a lower bound on the emission of Sgr~A* at 0.25 mm, the first such constraint on the THz portion of the SED. The variability on few hour timescales in the SPIRE light curves is similar to that seen in historical 1.3 mm data, where the longest time series is available, but the distribution of variations in the sub-mm do not show a tail of large-amplitude variations seen at 1.3 mm. Simultaneous X-ray photometry from XMM-Newton shows no significant variation within our observing period, which may explain the lack of very large variations if X-ray and submillimeter flares are correlated.Comment: Accepted for publication in Ap

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

Testing the Isotropy of the Universe with Type Ia Supernovae

We analyze the magnitude-redshift data of type Ia supernovae included in the Union and Union2 compilations in the framework of an anisotropic Bianchi type I cosmological model and in the presence of a dark energy fluid with anisotropic equation of state. We find that the amount of deviation from isotropy of the equation of state of dark energy, the skewness \delta, and the present level of anisotropy of the large-scale geometry of the Universe, the actual shear \Sigma_0, are constrained in the ranges -0.16 < \delta < 0.12 and -0.012 < \Sigma_0 < 0.012 (1\sigma C.L.) by Union2 data. Supernova data are then compatible with a standard isotropic universe (\delta = \Sigma_0 = 0), but a large level of anisotropy, both in the geometry of the Universe and in the equation of state of dark energy, is allowed.Comment: 12 pages, 7 figures, 2 tables. Union2 analysis added. New references added. To appear in Phys. Rev.

A Method for Individual Source Brightness Estimation in Single- and Multi-band Data

We present a method of reliably extracting the flux of individual sources from sky maps in the presence of noise and a source population in which number counts are a steeply falling function of flux. The method is an extension of a standard Bayesian procedure in the millimeter/submillimeter literature. As in the standard method, the prior applied to source flux measurements is derived from an estimate of the source counts as a function of flux, dN/dS. The key feature of the new method is that it enables reliable extraction of properties of individual sources, which previous methods in the literature do not. We first present the method for extracting individual source fluxes from data in a single observing band, then we extend the method to multiple bands, including prior information about the spectral behavior of the source population(s). The multi-band estimation technique is particularly relevant for classifying individual sources into populations according to their spectral behavior. We find that proper treatment of the correlated prior information between observing bands is key to avoiding significant biases in estimations of multi-band fluxes and spectral behavior, biases which lead to significant numbers of misclassified sources. We test the single- and multi-band versions of the method using simulated observations with observing parameters similar to that of the South Pole Telescope data used in Vieira, et al. (2010).Comment: 11 emulateapj pages, 3 figures, revised to match published versio