Mid Campanian-Lower Maastrichtian magnetostratigraphy of the James Ross Basin, Antarctica: Chronostratigraphical implications

The James Ross Basin, in the northern Antarctic Peninsula, exposes which is probably the world thickest and most complete Late Cretaceous sedimentary succession of southern high latitudes. Despite its very good exposures and varied and abundant fossil fauna, precise chronological determination of its infill is still lacking. We report results from a magnetostratigraphic study on shelfal sedimentary rocks of the Marambio Group, southeastern James Ross Basin, Antarctica. The succession studied covers a ~1,200 m-thick stratigraphic interval within the Hamilton Point, Sanctuary Cliffs and Karlsen Cliffs Members of the Snow Hill Island Formation, the Haslum Crag Formation, and the lower López de Bertodano Formation. The basic chronological reference framework is given by ammonite assemblages, which indicate a Late Campanian – Early Maastrichtian age for the studied units. Magnetostratigraphic samples were obtained from five partial sections located on James Ross and Snow Hill islands, the results from which agree partially with this previous biostratigraphical framework. Seven geomagnetic polarity reversals are identified in this work, allowing to identify the Chron C32/C33 boundary in Ammonite Assemblage 8-1, confirming the Late Campanian age of the Hamilton Point Member. However, the identification of the Chron C32/C31 boundary in Ammonite Assemblage 8-2 assigns the base of the Sanctuary Cliffs Member to the early Maastrichtian, which differs from the Late Campanian age previously assigned by ammonite biostratigraphy. This magnetostratigraphy spans ~14 Ma of sedimentary succession and together with previous partial magnetostratigraphies on Early-Mid Campanian and Middle Maastrichtian to Danian columns permits a complete and continuous record of the Late Cretaceous distal deposits of the James Ross Basin. This provides the required chronological resolution to solve the intra-basin and global correlation problems of the Late Cretaceous in the Southern Hemisphere in general and in the Weddellian province in particular, given by endemism and diachronic extinctions on invertebrate fossils, including ammonites. The new chronostratigraphic scheme allowed us to calculate sediment accumulation rates for almost the entire Late Cretaceous infill of the distal James Ross Basin (the Marambio Group), showing a monotonous accumulation for more than 8 Myr during the upper Campanian and a dramatic increase during the early Maastrichtian, controlled by tectonic and/or eustatic causes.Fil: Milanese, Florencia Nidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Olivero, Eduardo Bernardo. Universidad Nacional de Tierra del Fuego; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Raffi, María Eugenia. Universidad Nacional de Tierra del Fuego; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Franceschinis, Pablo Reinaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Gallo, Leandro César. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Skinner, Steven M.. California State University; Estados UnidosFil: Mitchell, Ross N.. California Institute of Technology; Estados UnidosFil: Kirschvink, Joseph L.. California Institute of Technology; Estados Unidos. Tokyo Institute of Technology; JapónFil: Rapalini, Augusto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentin

All-carbon multi-electrode array for real-time in vitro measurements of oxidizable neurotransmitters

We report on the ion beam fabrication of all-carbon multi electrode arrays (MEAs) based on 16 graphitic micro-channels embedded in single-crystal diamond (SCD) substrates. The fabricated SCD-MEAs are systematically employed for the in vitro simultaneous amperometric detection of the secretory activity from populations of chromaffin cells, demonstrating a new sensing approach with respect to standard techniques. The biochemical stability and biocompatibility of the SCD-based device combined with the parallel recording of multi-electrodes array allow: i) a significant time saving in data collection during drug screening and/or pharmacological tests over a large number of cells, ii) the possibility of comparing altered cell functionality among cell populations, and iii) the repeatition of acquisition runs over many cycles with a fully non-toxic and chemically robust bio-sensitive substrate.Comment: 24 pages, 5 figure

A methodological proposal and tool support for the HL7 standards compliance in the development of health information systems

Health information systems are increasingly complex, and their development is presented as a challenge for software development companies offering quality, maintainable and interoperable products. HL7 (Health level 7) International, an international non-profit organization, defines and maintains standards related to health information systems. However, the modelling languages proposed by HL7 are far removed from standard languages and widely known by software engineers. In these lines, NDT is a software development methodology that has a support tool called NDT-Suite and is based, on the one hand, on the paradigm of model-driven engineering and, on the other hand, in UML that is a widely recognized standard language. This paper proposes an extension of the NDT methodology called MoDHE (Model Driven Health Engineering) to offer software engineers a methodology capable of modelling health information systems conforming to HL7 using UML domain models

Photocurrent study of beta-ray priming in CVD diamond

Priming by X-rays or by beta-rays is generally needed in order to qualify CVD diamond for nuclear detection or for dosimetry. The priming effect is usually attributed in filling the hole traps, which are responsible for the charge collection efficiency of the detector. Emptying the filled traps can be easily detected by Thermoluminescence (TL), which is considered to be a measure of the absorbed dose. In this work, we prove that below-gap photocurrent (BGPC) can also be used in the same way and it is dominated by the optical detrapping of holes from the same centers. Time dependence of this beta-rays induced persistent photocurrent (PPC), which in fact, depends only on the total number of photons impinging onto the sample. In fact, at long times or for large number of photons, the photocurrent approaches to the same limit of PC for a null dose. The hole trapping centers distribution seems to extend from 1.25 to 2.5 eV valence band

Ion and X-ray micro-beam induced charge collection and their applications in CVD diamond detector characterisation

We have used a micrometer size X-ray beam generated from a synchrotron light source at the European Synchrotron Radiation Facility (ESRF) in Grenoble and a 2 MeV proton micro-beam at the Italian National Laboratory (LNL) of Legnaro to image the electronic transport properties of a CVD diamond detector developed within the CERN RD42 collaboration. The focused X-rays or protons are scanned over the device surface, and the induced current or charge pulse is measured and plotted on two dimensional maps. Due to the polycrystalline nature of the material, the maps are not homogeneous and both the techniques show structures ascribable to diamond grains. It was found that the uniformity of the maps depends on the lateral scale (binning) and on the analytical depth of the micro-probes

Influence of the bias-voltage on the anchoring energy for nematic liquid crystals

The influence of the bias-voltage on the anisotropic part of the nematic surface energy is analyzed. The experimental data show a strong dependence of the anchoring strength on the bias-voltage when the electrodes of the nematic cell are covered with WO3. The observed dependence can be interpreted taking into account the ions dissolved in the liquid crystal. We propose a model in which the effect of the bias-voltage is to collect the ions near the electrodes, in a surface layer whose thickness is of the order of the Debye’s screening length. The surplus of electric field due to this ions confinement gives rise to an electrostatic contribution to the total energy that can be considered as a surface energy. The proposed model is in good agreement with the experimental data. The model is used to interpret the observed independence of the anchoring strength on the bias-voltage when the indium-oxide electrode is covered with a film of polyimide, or it is without any covering. The influence of a charge emission from the electrodes under the bias voltage on the anchoring energy is also analyzed. Possible applications of the observed phenomenon are discussed

The added value of simultaneous palpation during scrotal ultrasound

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Reactions radicalaires dans des milieux protiques et aprotiques : comparaisons entre les cyclisations reductives electrochimiques catalysees par des complexes du nickel

The electrochemical reductive cyclisation of unsaturated organic halides in the presence of Ni(II) complexes as catalysts was examined in aprotic solvents such as DMF and in protic solvents such as ethanol, butanol or ethanolewater mixtures. The presence of the alcohol media enhanced the rate of recycling of the catalytic species.La cyclisation réductive électrochimique d’halogénures insaturés en présence de complexes de Ni(II) comme catalyseurs a été examinée dans des solvants comme le DMF et dans des solvants protiques comme l’éthanol, le butanol ou des mélanges éthanol-eau. La présence du milieu alcoolique augmente la vitesse du recyclage des espèces catalytiques.Fundação para a Ciência e a Tecnologia (FCT