2,177 research outputs found

    Le api svelano il mistero delle fonti di emissione di particolato inquinante

    No full text
    Si tratta di una ricerca che è durata due anni, ed è stata pubblicata sul numero di luglio 2015 della Rivista scientifica internazionale Plos One. Gli autori: Ilaria Negri, Marco Pellecchia (Koiné - Consulenze Ambientali S.n.c., Parma, Italy), Christian Mavris (Department of Earth Sciences, Natural History Museum, London, United Kingdom), Gennaro Di Prisco, Emilio Caprio (Dipartimento di Agraria, Laboratorio di Entomologia E. Tremblay, Università degli Studi di Napoli Federico II, Portici - Napoli). Nello studio scientifico i ricercatori dimostrano che le api si comportano anche come “campionatori” attivi di particolato atmosferico, i cosiddetti PM (dall’inglese “Particulate Matter”), di cui sono ricche le nostre città come troppo spesso avvertono i dati dell’Agenzia Regionale di Protezione dell’Ambiente (ARPA). Dice che l’Iglesiente (Iglesias, Sardegna) è inquinato, fortemente contaminato da metalli pesanti come il piombo e il bario. E svela poi che la salute di chi ci vive potrebbe essere compromessa, se non lo è già, anche dall’alta concentrazione di ferro, silicio e alluminio. Rivela ancora, con scientifica precisione, da dove provengono le micro particelle di queste impercettibilissime polveri: dalle miniere dell’Iglesiente e dalle industrie di Portovesm

    Defense Mechanisms, Gender, and Adaptiveness in Emerging Personality Disorders in Adolescent Outpatients

    Get PDF
    The present study focused on demographic and personality differences in the use of 30 defense mechanisms in adolescents with personality psychopathology and explored the hierarchical organization of personality traits based on the adaptiveness of defensive functioning. A total of 102 self-referred adolescent outpatients were interviewed and assessed on defense mechanisms and personality traits using the Defense Mechanisms Rating Scales and the Shedler-Westen Assessment Procedure 200 for Adolescents, respectively. Age and gender differences were found throughout the hierarchy. Pearson's correlations revealed a hierarchical organization of emerging personality disorders (PDs) in adolescence. More adaptive defenses were clearly associated with healthier personality style, whereas more pathological personality styles such as those with borderline traits were characterized by more rigid and maladaptive defenses. Dissociation was also associated with maladaptive personality types. Identifying the defenses associated with emerging personality disorders may inform the unconscious function of defense mechanisms in specific PDs. The systematic assessment of defense mechanisms might also help therapists to monitor changes during treatment

    Experimental evidence of s-wave superconductivity in bulk CaC6_{6}

    Full text link
    The temperature dependence of the in-plane magnetic penetration depth, λab(T)\lambda_{ab}(T), has been measured in a c-axis oriented polycrystalline CaC6_{6} bulk sample using a high-resolution mutual inductance technique. A clear exponential behavior of λab(T)\lambda_{ab}(T) has been observed at low temperatures, strongly suggesting isotropic s-wave pairing. Data fit using the standard BCS theory yields λab(0)=(720±80)\lambda_{ab}(0)=(720\pm 80) Angstroem and Δ(0)=(1.79±0.08)\Delta(0)=(1.79\pm 0.08) meV. The ratio 2Δ(0)/kBTc=(3.6±0.2)2\Delta(0)/k_{_B}T_{c}=(3.6\pm 0.2) gives indication for a conventional weakly coupled superconductor.Comment: To appear in Phys. Rev. Let

    Production of laccase by Botrytis cinerea and fermentation studies with strain F226

    Get PDF
    After induction, seven strains ofBotrytis cinerea released into the culture broth considerable amounts of laccase in a brief production time. The set-up of a suitable production process was studied with a selected strain in a 10-L fermenter. The optimum fermentation conditions were a 3% inoculum with a high degree of sporulation, a simple medium containing 20 g L−1 of glucose and 2 g L−1 of yeast extract at pH 3.5, 2 g L−1 gallic acid as inducer, added after 2 days of growth, an agitation speed of 300 rpm, an aeration rate of 1.2 vvm and a temperature of 24°C. By optimizing the culture conditions, the enzyme activity reached 28 U ml−1 in 5 days with a specific activity of 560 U mg−1 protein. The best procedure to obtain a suitable crude enzyme preparation was concentration of the supernatant medium to 10% of the initial volume by ultrafiltration, followed by a fractional precipitation with ethanol. The optimum pH and temperature for laccase activity were 5.5 and 40°C, respectively, with syringaldazine as the substrate

    Transport in strongly-coupled graphene-LaAlO3/SrTiO3 hybrid systems

    Full text link
    We report on the transport properties of hybrid devices obtained by depositing graphene on a LaAlO3/SrTiO3 oxide junction hosting a 4 nm-deep two-dimensional electron system. At low graphene-oxide inter-layer bias the two electron systems are electrically isolated, despite their small spatial separation, and very efficient reciprocal gating is shown. A pronounced rectifying behavior is observed for larger bias values and ascribed to the interplay between electrostatic depletion and tunneling across the LaAlO3 barrier. The relevance of these results in the context of strongly-coupled bilayer systems is discussed.Comment: 10 pages, 3 figure

    Cosmic dance in the Shapley Concentration Core - I. A study of the radio emission of the BCGs and tailed radio galaxies

    Get PDF
    The Shapley Concentration (z0.048z\approx0.048) covers several degrees in the Southern Hemisphere, and includes galaxy clusters in advanced evolutionary stage, groups of clusters in the early stages of merger, fairly massive clusters with ongoing accretion activity, and smaller groups located in filaments in the regions between the main clusters. With the goal to investigate the role of cluster mergers and accretion on the radio galaxy population, we performed a multi-wavelength study of the BCGs and of the galaxies showing extended radio emission in the cluster complexes of Abell 3528 and Abell 3558. Our study is based on a sample of 12 galaxies. We observed the clusters with the GMRT at 235, 325 and 610 MHz, and with the VLA at 8.46 GHz. We complemented our study with the TGSS at 150 MHz, the SUMSS at 843 MHz and ATCA at 1380, 1400, 2380, and 4790 MHz data. Optical imaging with ESO-VST and mid-IR coverage with WISE are also available for the host galaxies. We found deep differences in the properties of the radio emission of the BCGs in the two cluster complexes. The BCGs in the A3528 complex and in A3556, which are relaxed cool-core objects, are powerful active radio galaxies. They also present hints of restarted activity. On the contrary, the BCGs in A3558 and A3562, which are well known merging systems, are very faint, or quiet, in the radio band. The optical and IR properties of the galaxies are fairly similar in the two complexes, showing all passive red galaxies. Our study shows remarkable differences in the radio properties of the BGCs, which we relate to the different dynamical state of the host cluster. On the contrary, the lack of changes between such different environments in the optical band suggests that the dynamical state of galaxy clusters does not affect the optical counterparts of the radio galaxies, at least over the life-time of the radio emission.Comment: 24 pages, 11 figures, accepted for publication in Astronomy & Astrophysic
    corecore