ITS2 in calanoid copepods: reconstructing phylogenetic relationships and identifying a newly introduced species in the Mediterranean

Phylogenetic inference and molecular taxonomy are becoming increasingly important approaches to classical morphological systematics and marine ecology. The number of molecular markers suitable for such goals is quite high, but general use restricts the list to a few of them, mainly mitochondrial (namely cytochrome c oxidase subunit I, COI and Cytochrome b), especially in copepods. The ribosomal cistronic regions have been widely used for broad phylogenetic analyses in different taxa. Among them, the internal transcribed spacers (ITS rDNA) are powerful tools for phylogenetic reconstructions at the different taxonomic levels, although not yet extensively used for copepods. In the present work, we tested the suitability of ITS2 rDNA marker to reconstruct the phylogenetic relationships of calanoid copepods using sequences retrieved from GenBank, complementing the phylogenetic positions of the species studied with their morphological and ecological traits. Through ITS2 rDNA we provided the first molecular evidence for the invasive calanoid Pseudodiaptomus marinus from the Mediterranean Sea (Lake Faro, Sicily, Italy), and compared it with the GenBank ITS2 sequences for P. marinus from Korea and other calanoid species. The divergence of the sequences of our P. marinus from those of Korean specimens was quite prominent (4.4%) and allowed us to hypothesise either a new forma living in the Mediterranean or a cryptic species. This study highlights the appropriateness of ITS2 for phylogenetic reconstructions and species identification, as well as for barcoding, meta-barcoding and phylogeographic approaches, and evidences the need for a more thorough knowledge of ribosomal regions in copepods from different sites

High quality MgB2 thin films in-situ grown by dc magnetron sputtering

Thin films of the recently discovered magnesium diboride (MgB2) intermetalic superconducting compound have been grown using a magnetron sputtering deposition technique followed by in-situ annealing at 830 C. High quality films were obtained on both sapphire and MgO substrates. The best films showed maximum Tc = 35 K (onset), a transition width of 0.5 K, a residual resistivity ratio up to 1.6, a low temperature critical current density Jc > 1 MA/cm2 and anisotropic critical field with gamma = 2.5 close to the values obtained for single crystals. The preparation technique can be easily scaled to produce large area in-situ films.Comment: 7 pages, 4 figure

Photodoping and in-gap interface states across the metal-insulator transition in LaAlO3/SrTiO3 heterostructures

By using scanning tunneling microscopy/spectroscopy we show that the interface between LaAlO3 and SrTiO3 band insulators is characterized by in-gap interface states. These features were observed in insulating as well as conducting LaAlO3/SrTiO3 bilayers. The data show how the interface density of states evolves across the insulating to metal transition, demonstrating that nanoscale electronic inhomogeneities in the system are induced by spatially localized electrons

Observation of a two-dimensional electron gas at the surface of annealed SrTiO3 single crystals by scanning tunneling spectroscopy

Scanning tunneling spectroscopy suggests the formation of a two dimensional electron gas (2DEG) on the TiO2 terminated surface of undoped SrTiO3 single crystals annealed at temperature lower than 400 {\deg}C in ultra high vacuum conditions. Low energy electron diffraction indicates that the 2D metallic SrTiO3 surface is not structurally reconstructed, suggesting that non-ordered oxygen vacancies created in the annealing process introduce carriers leading to an electronic reconstruction. The experimental results are interpreted in a frame of competition between oxygen diffusion from the bulk to the surface and oxygen loss from the surface itself.Comment: 9 pages, 3 figures, submitted to Physical Review

Orthostatic headache and bilateral abducens palsy secondary to spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) is a well-documented syndrome characterized typically by a benign, self-limited course. Patients typically present with postural or exertional headaches that can be temporarily relieved by lying in a supine or recumbent position. A 35-year-old Caucasian male suffered orthostatic headache that developed to a bilateral abducens palsy. We ordered relative rest and the patient improved and completely recovered after 3 months. Although SIH is considered as a benign and self limited process it could also be associated with disabling complications. We should be aware of the possible complications and inform our patients. SIH can present with headache and bilateral abducens palsy even when the headache is improving

Leading order analysis of neutrino induced dimuon events in the CHORUS experiment

We present a leading order QCD analysis of a sample of neutrino induced charged-current events with two muons in the final state originating in the lead-scintillating fibre calorimeter of the CHORUS detector. The results are based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign dimuon events collected during the exposure of the detector to the CERN Wide Band Neutrino Beam between 1995 and 1998. % with $E_{\mu 1},E_{\mu 2} > 5$ GeV and $Q^2 > 3$ GeV$^2$ collected %between 1995 and 1998. The analysis yields a value of the charm quark mass of \mc = (1.26\pm 0.16 \pm 0.09) \GeVcc and a value of the ratio of the strange to non-strange sea in the nucleon of $\kappa = 0.33 \pm 0.05 \pm 0.05$, improving the results obtained in similar analyses by previous experiments.Comment: Submitted to Nuclear Physics

Electron/pion separation with an Emulsion Cloud Chamber by using a Neural Network

We have studied the performance of a new algorithm for electron/pion separation in an Emulsion Cloud Chamber (ECC) made of lead and nuclear emulsion films. The software for separation consists of two parts: a shower reconstruction algorithm and a Neural Network that assigns to each reconstructed shower the probability to be an electron or a pion. The performance has been studied for the ECC of the OPERA experiment [1]. The $e/\pi$ separation algorithm has been optimized by using a detailed Monte Carlo simulation of the ECC and tested on real data taken at CERN (pion beams) and at DESY (electron beams). The algorithm allows to achieve a 90% electron identification efficiency with a pion misidentification smaller than 1% for energies higher than 2 GeV

Measurement of the production of charged pions by protons on a tantalum target

A measurement of the double-differential cross-section for the production of charged pions in proton--tantalum collisions emitted at large angles from the incoming beam direction is presented. The data were taken in 2002 with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 \GeVc to 12 \GeVc hitting a tantalum target with a thickness of 5% of a nuclear interaction length. The angular and momentum range covered by the experiment (100 \MeVc \le p < 800 \MeVc and 0.35 \rad \le \theta <2.15 \rad) is of particular importance for the design of a neutrino factory. The produced particles were detected using a small-radius cylindrical time projection chamber (TPC) placed in a solenoidal magnet. Track recognition, momentum determination and particle identification were all performed based on the measurements made with the TPC. An elaborate system of detectors in the beam line ensured the identification of the incident particles. Results are shown for the double-differential cross-sections ${{\mathrm{d}^2 \sigma}} / {{\mathrm{d}p\mathrm{d}\theta}}$ at four incident proton beam momenta (3 \GeVc, 5 \GeVc, 8 \GeVc and 12 \GeVc). In addition, the pion yields within the acceptance of typical neutrino factory designs are shown as a function of beam momentum. The measurement of these yields within a single experiment eliminates most systematic errors in the comparison between rates at different beam momenta and between positive and negative pion production.Comment: 49 pages, 31 figures. Version accepted for publication on Eur. Phys. J.