New insight into the Pleistocene deposits of Monte delle Piche, Rome, and remarks on the biochronology of Hippopotamus (Mammalia, Hippopotamidae) and Stephanorhinus etruscus (Mammalia, Rhinocerotidae) in Italy

Several large mammal assemblages have been collected in the Roman basin since the XIX century, but they usually lack any stratigraphic datum or details about the fossiliferous localities. In this work, the stratigraphic provenance of large mammal remains discovered at Monte delle Piche (Rome) is investigated. The systematic revision of these specimens allows the recording of the presence of Hippopotamus sp., Stephanorhinus sp. and Stephanorhinus etruscus. On the basis of micropalaeontological analysis performed on sediment sampled from the studied specimens and considering the stratigraphy of the area, two fossiliferous levels are recognised at Monte delle Piche. The remain of the hippopotamus was collected in fluvial gravels and sand deposits, in which the presence of Cyprideis is also recorded. This deposit is chronologically related to the latest Early-early Middle Pleistocene. Hippopotamus was present in Italy and Western Europe from the latest Villafranchian to MIS 4/3. The mandible of S. etruscus was collected in marine deposits along with abundant foraminifera and ostracods, which correlate with the late Early Pleistocene. Stephanorhinus etruscus occurred in Western Europe at the beginning of the Villafranchian, and it was documented until the end of the Villafranchian in Italy and until the Early-Middle Pleistocene transition in the Iberian Peninsula

Facing Non-Stationary Conditions with a New Indicator of Entropy Increase: The Cassandra Algorithm

We address the problem of detecting non-stationary effects in time series (in particular fractal time series) by means of the Diffusion Entropy Method (DEM). This means that the experimental sequence under study, of size $N$, is explored with a window of size $L << N$. The DEM makes a wise use of the statistical information available and, consequently, in spite of the modest size of the window used, does succeed in revealing local statistical properties, and it shows how they change upon moving the windows along the experimental sequence. The method is expected to work also to predict catastrophic events before their occurrence.Comment: FRACTAL 2002 (Spain

Prospects for Stochastic Background Searches Using Virgo and LSC Interferometers

We consider the question of cross-correlation measurements using Virgo and the LSC Interferometers (LIGO Livingston, LIGO Hanford, and GEO600) to search for a stochastic gravitational-wave background. We find that inclusion of Virgo into the network will substantially improve the sensitivity to correlations above 200 Hz if all detectors are operating at their design sensitivity. This is illustrated using a simulated isotropic stochastic background signal, generated with an astrophysically-motivated spectrum, injected into 24 hours of simulated noise for the LIGO and Virgo interferometers.Comment: 11 pages, uses IOP style files, submitted to CQG for GWDAW11 proceedings; revised in response to referee comment

Compression and diffusion: a joint approach to detect complexity

The adoption of the Kolmogorov-Sinai (KS) entropy is becoming a popular research tool among physicists, especially when applied to a dynamical system fitting the conditions of validity of the Pesin theorem. The study of time series that are a manifestation of system dynamics whose rules are either unknown or too complex for a mathematical treatment, is still a challenge since the KS entropy is not computable, in general, in that case. Here we present a plan of action based on the joint action of two procedures, both related to the KS entropy, but compatible with computer implementation through fast and efficient programs. The former procedure, called Compression Algorithm Sensitive To Regularity (CASToRe), establishes the amount of order by the numerical evaluation of algorithmic compressibility. The latter, called Complex Analysis of Sequences via Scaling AND Randomness Assessment (CASSANDRA), establishes the complexity degree through the numerical evaluation of the strength of an anomalous effect. This is the departure, of the diffusion process generated by the observed fluctuations, from ordinary Brownian motion. The CASSANDRA algorithm shares with CASToRe a connection with the Kolmogorov complexity. This makes both algorithms especially suitable to study the transition from dynamics to thermodynamics, and the case of non-stationary time series as well. The benefit of the joint action of these two methods is proven by the analysis of artificial sequences with the same main properties as the real time series to which the joint use of these two methods will be applied in future research work.Comment: 27 pages, 9 figure

VLBA determination of the distance to nearby star-forming regions I. The distance to T Tauri with 0.4% accuracy

In this article, we present the results of a series of twelve 3.6-cm radio continuum observations of T Tau Sb, one of the companions of the famous young stellar object T Tauri. The data were collected roughly every two months between September 2003 and July 2005 with the Very Long Baseline Array (VLBA). Thanks to the remarkably accurate astrometry delivered by the VLBA, the absolute position of T Tau Sb could be measured with a precision typically better than about 100 micro-arcseconds at each of the twelve observed epochs. The trajectory of T Tau Sb on the plane of the sky could, therefore, be traced very precisely, and modeled as the superposition of the trigonometric parallax of the source and an accelerated proper motion. The best fit yields a distance to T Tau Sb of 147.6 +/- 0.6 pc. The observed positions of T Tau Sb are in good agreement with recent infrared measurements, but seem to favor a somewhat longer orbital period than that recently reported by Duchene et al. (2006) for the T Tau Sa/T Tau Sb system.Comment: 24 pages, 3 pages, AASTEX format, accepted for publication in Ap

Myringotomy and ventilation tube insertion with endoscopic or microscopic technique in adults: a pilot study

The purpose of this study is to assess the feasibility of endoscopic-assisted myringotomy and ventilation tube insertion in adults affected by chronic otitis media with effusion, comparing the outcomes of this approach with those obtained with the traditional microscopic technique. Twenty-four patients were enrolled in this trial and alternately assigned to 2 groups of 12 subjects each. In group A, patients underwent myringotomy and ventilation tube insertion under endoscopic view, whereas in group B, the same procedure was performed traditionally using a microscope. All cases were evaluated 1 week after surgery and then monthly until tube extrusion. Type A tympanogram was achieved in 10 of 13 ears in both groups (76.92%). No significant difference in operative times or complication rates was observed (P &gt; .05). Endoscopic technique could be a viable alternative to the microscopic approach for myringotomy and ventilation tube positioning in adults affected by chronic otitis media with effusion

Introduction into Italy of Gryon pennsylvanicum (Ashmead), an egg parasitoid of the alien invasive bug Leptoglossus occidentalis Heidemann

Leptoglossus occidentalis (Heteroptera, Coreidae), a Nearctic species, was accidentally introduced into Northern Italy in the late 1990s, from where it has spread throughout Europe. The bug causes abortion of immature cones of Pinus pinea L., with economic impact on the pine-nut industry. As part of a pest control research program, the egg parasitoid Gryon pennsylvanicum Ashmead (Hymenoptera, Platygastridae) was collected from British Columbia, Canada, and legally introduced to a quarantine climatic chamber in Florence, Italy. The egg parasitoid will be tested against native non target heteropterans, an environmental impact assessment will be conducted, and a mass rearing method will be developed if appropriate. The ultimate goal is to release G. pennsylvanicum into Italian P. pinea forests for classical biological control of L. occidentalis

Anisotropic pinning enhancement in Nb films with arrays of submicrometric Ni lines

Arrays of submicrometric Ni lines have been fabricated in superconducting Nb films by electron beam lithography. In the mixed state, these arrays induce strong anisotropy in the dissipation behavior. The dissipation is reduced several orders of magnitude, in the whole applied magnetic field range, when the vortex motion is perpendicular to the Ni lines (applied current parallel to them) in comparison with dissipation of vortices moving parallel to the lines. In addition, for the samples studied in this work, a change in the slope of the ρ(B) curves is observed when the vortices move perpendicular to the lines and the vortex lattice parameter matches the width of the Ni lines. © 2002 American Institute of Physics.The authors want to thank Spanish CICYT MAT2002- 04543 and ESF Vortex program. D.J. and E.M.G. thank Ministerio de Ciencia y Tecnologı´a ~Spain! for Ramo´n y Cajal Contracts.Peer reviewe

Invasive species and habitat degradation in Iberian streams: An analysis of their role in freshwater fish diversity loss

Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives' decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions