Interpreting the production of 26Al in Antarctic meteorites

Large numbers of meteorites have been concentrated at several locations in Antarctica. Glaciological mechanisms of grossly different time scales have been proposed to account for their transport by the ice, and the frequency distribution of the terrestrial ages of these objects has been suggested as a means of determining the relevant time scales. The upper limit to the ages of ice in Antarctica which would emerge from such a project is of interest to many other disciplines. After a meteorite reaches the Earth's surface, the specific radioactivity of Al-26 produced by cosmic rays while it was in space decreases because shielding by the Earth's atmosphere reduces further production to a neglible level. Thus, the known half life of this species can be used to determine the object's terrestrial age if the specific radioactivity at time of fall can be determined with reasonable accuracy and precision. The several models utilized for these predictions were based on the limited data available nearly two decades ago. The much larger data base now available was examined using multiple parameter regression analyses

El Instituto de el autor detrás del autor en los aparatos organizados de poder y su tan solo ontológico trascendencia, algunas consideraciones críticas sobre los fundamentos de la responsabilidad jurídico-penal del superior jerárquico

Publicación a texto completo no autorizada por el autorDesarrolla la configuración de la responsabilidad en el marco de un aparato organizado de poder paraestatal y estatal (los fundamentos de las figuras con los que se responsabilizan a los sujetos de escritorio). En ese sentido se partió por tratar las diferentes posturas que se han ensayado para la determinación de la responsabilidad y cómo esas posturas van siendo adoptadas por la Jurisprudencia penal nacional e internacional. Se fundamenta en elementos netamente normativos, prescindiendo, de esta manera, de instrumentos ontológicos o naturalísticos. Se sostuvo que las responsabilidades se levantan sobre la infracción de dos tipos de deberes: Generales negativos y especiales positivos, en el primero se postuló una coautoría, para el fenómeno objeto de la investigación, y en el segundo una autoría directa, para con aparatos paraestatales y estatales respectivamente. Por tanto, se rechazó plenamente la figura de autoría mediata por no tener claridad ni fundamentos normativos, como tiene que ser, ya que nos encontramos en sistema normativo y no fáctico.Tesi

A generic xml language for characterising objects to support digital preservation

The dominance of digital objects in today’s information landscape has changed the way humankind creates and exchanges information. However, it has also brought an entirely new problem: the longevity of digital objects. Due to the fast changes in technologies, digital documents have a short lifespan before they become obsolete. Digital preservation, i.e. actions to ensure longevity of digital information, thus has become a pressing challenge. Different strategies such as migration and emulation have been proposed; however, the decision between available tools for format migration is very complex. Preservation planning supports decision makers in reaching accountable decisions by evaluating potential strategies against well-defined requirements. Especially the evaluation of different migration tools for digital preservation has to rely on validating the converted objects and thus on an analysis of the logical structure and the content of documents. This paper presents the eXtensible Characterisation Languages (XCL) that support the automatic validation of document conversions and the evaluation of migration quality by hierarchically decomposing a document and XML language. We present the context of the development of these languages and tools and describe the overall concept and features of the languages and how they can be applied to the evaluation of digital preservation solutions

Systematic Characterisation of Objects in Digital Preservation: The eXtensible Characterisation Languages

Abstract: During the last decades, digital objects have become the primary medium to create, shape, and exchange information. However, in contrast to analog objects such as books that directly represent their content, digital objects are not usable without a corresponding technical environment. The fast changes in these environments and in formats and technologies mean that digital documents have a short lifespan before they become obsolete. Digital preservation, i.e. actions to ensure longevity of digital information, thus has become a pressing challenge. The dominant strategies prevailing today are migration and emulation; for each strategy, different tools are available. When converting an object to a different representation, a validation of the content is needed to verify that the transformed objects are still authentically representing the same intellectual content. This validation so far is largely done manually, which is infeasible for large collections. Preservation planning supports decision makers in reaching accountable decisions by evaluating potential strategies against well-defined requirements. Especially the evaluation of different migration tools for digital preservation has to rely on validating th