Late Cretaceous to Eocene calcareous nannofossil distribution near Gubbio, Italy

Using a modified sample preparation technique, we have been able to establish a detailed lower Campanian to upper Eocene nannofossil stratigraphy in the Bottaccione and Contessa Highway sections near Gubbio. Appearance and extinction levels of virtually all the commonly used calcareous nannofossil zonal markers have been recognized and can now be closely correlated with the planktonic foraminifera zonation and the magnetic reversal stratigraphy previously established in these sections. Comparisons with the nannofossil calibrations of the oceanic magnetic anomaly sequence in Deep Sea Drilling Project (DSDP) sites suggest that magmetic Subchrons C17N and C25N are missing in the Bottaccione section. The observed variability of the relative stratigraphic position of most plankton events is confirmed to less than one magnetic subchron. Absolute abundance, paleobiogeographic restriction, and differential preservation render some of the traditionally used biostratigraphic events less reliable than others.

Geografía y transformación con inteligencia territorial : investigación-acción y transposición didáctica

El presente trabajo refiere a concepciones teóricas de la Geografía, la Transformación y la Inteligencia Territorial (Girardot, 2009) como perspectivas y como herramientas útiles y articuladas para trabajar en la escuela en el marco de procesos de transposición didáctica (Chevallard, 1991). Se articulan estas concepciones con perspectivas científicas en el marco de un paradigma emergente (de Sousa, 2009) así como de investigación-acción-participativa (Fals Borda, 1986, 2009) y del proyecto como un objeto, no sólo de estudio sino de intervención y transformación (Bozzano, 2012). Finalmente, se presentan tres propuestas de transposición didáctica impulsadas por docentes de localidades del sur de Santa Fe (Argentina) en el marco del diálogo teórico y científico planteado en este trabajo. En las conclusiones se abre a nuevas reflexiones científicas en cuatro líneas referidas a: predisposiciones y resistencias; diálogos de saberes (Freire, 1996) en clave de Inteligencia Territorial, una Geografía más útil y atractiva; y geo-transformare, una Geografía con Inteligencia Territorial.

Investigation of Bacteria in coastal waters of King George Island

We determined the numbers of free-living and associated (aggregated or bonded with particles) bacteria in the coastal water of King George Island at an offshore (St. 1) and a nearshore station (St. 2) as a function of physico-chemical parameters. Water sampIes were collected between March and October at St. 1 and between April and October at St. 2. Direct counts of total bacteria varied from 0.53*10**8 to 5.02*10**8 cells/l. Associated microorganisms accounted for 5 to 20 % of the total number of bacteria. Strong Spearman and Pearson correlations were observed (R = 0.82; P = 0.001) between the numbers of free-living and associated bacteria at St. 1. These two groups of bacteria were nearly evenly distributed in the horizontal transects from inshore to offshore waters at depths of 1-10 m in Ardley Cove. There were no substantial differences in the numbers of either free-living or associated bacteria in vertical transects too. Their number at St. 1, but not at St. 2, correlated significantly with all tested environmental parameters (salinity, temperature, solar radiation, nitrate, phosphate and chlorophyll a concentrations), except nitrite concentrations in water. The most probable reason for these correlations is that a common seasonal trend is characteristic of most tested parameters during the March to October period.

Oligocene strontium isotope stratigraphy of Indian Ocean sediments

Strontium isotope (87Sr/86Sr) ages have been established for Oligocene samples of Leg 119 Site 744, Leg 120 Sites 747 and 748, and Leg 121 Sites 756 and 757. Ages were determined using the strontium isotope age equation of Miller et al. (1988) and preliminary correlations have been made with available nannofossil biostratigraphy. The strontium isotope ages calculated here augment biostratigraphy, which for the Oligocene is characterized by long biozones, and provide additional detail where the paleomagnetic record is not clear (Sites 756 and 757). Results from the lower latitude Ninetyeast Ridge sites where standard calcareous nannofossil datums are present are compared to those of the higher latitude Kerguelen Plateau sites in order to examine biostratigraphic events across latitude in the Indian Ocean. The 87Sr/86Sr determined ages are used here as a tool for correlation.

Mineralogy of Hawaiian Arch sediments

The mineralogy of both bulk- and clay-sized (<2 µm) fractions of sediments from Holes 842A and 842B of Ocean Drilling Program Leg 136 was determined by X-ray diffraction. The sediments consist of a combination of terrigenous (quartz, plagioclase, smectite, illite, kaolinite, and chlorite), volcaniclastic (augite, plagioclase, and volcanic glass), and diagenetic minerals (smectite, phillipsite, clinoptilolite, and opal-CT). Although biogenic silica (radiolarians and diatoms) is common in near-seafloor (<10 mbsf) sediments, biogenic calcite is rare. Variations with depth in abundances of the terrigenous minerals reflect temporal changes in the flux of eolian material to the site. Volcanogenic material derived from the Hawaiian Islands is present in lithologic Unit 1 (0-19.9 meters below seafloor) both as discrete layers and as finely disseminated silt- and clay-sized material. Volcanic glass is present only in the upper 10 m of the sediment column. In Unit 2 (19.9-35.7 mbsf), increased smectite and zeolite abundances with depth as well as indurated, zeolite-rich layers are thought to be the alteration products of volcanogenic material. The source of this older (late Oligocene to middle Miocene) volcanogenic detritus may be continental volcanism. Microfabrics imaged using back-scattered electron imaging reflect the effects of compaction and diagenesis on sediment porosity and matrix structure. As porosity decreases during burial, the matrix changes from an open, floc-like fabric, to an interlocking network of clay mineral domains, and finally to a dense intergrowth of clay minerals and zeolites. Despite the substantial changes in sediment microfabric and mineralogy, correlations between physical and acoustic properties and mineralogy are weak or absent. The sediment has maintained high porosity (>70%), and water content appears to dominate the sediment's physical character and acoustic response.

Usability-Oriented Software Development Process

Usability is the capability of the software product to be understood, learned, used and attractive to the user, when used under specified conditions. Many studies demonstrate the benefits of usability, yet to this day software products continue to exhibit consistently low levels of this quality attribute. Furthermore, poor usability in software systems contributes largely to software failing in actual use. One of the main disciplines involved in usability is that of Human-Computer Interaction (HCI). Over the past two decades the HCI community has proposed specific features that should be present in applications to improve their usability, yet incorporating them into software continues to be far from trivial for software developers. These difficulties are due to multiple factors, including the high level of abstraction at which these HCI recommendations are made and how far removed they are from actual software implementation. In order to bridge this gap, the Software Engineering community has long proposed software design solutions to help developers include usability features into software, however, the problem remains an open research question. This doctoral thesis addresses the problem of helping software developers include specific usability features into their applications by providing them with a structured and tangible guidance in the form of a process, which we have termed the Usability-Oriented Software Development Process. This process is supported by a set of Software Usability Guidelines that help developers to incorporate a set of eleven usability features with high impact on software design. After developing the Usability-oriented Software Development Process and the Software Usability Guidelines, they have been validated across multiple academic projects and proven to help software developers to include such usability features into their software applications. In doing so, their use significantly reduced development time and improved the quality of the resulting designs of these projects. Furthermore, in this work we propose a software tool to automate the application of the proposed process. In sum, this work contributes to the integration of the Software Engineering and HCI disciplines providing a framework that helps software developers to create usable applications in an efficient way.

Evaluation of the influence of visual parameters on wave transmission velocity in sawn chestnut timber

Non-destructive, visual evaluation and mechanical testing techniques were used to assess the structural properties of 374 samples of chestnut (Castanea sativa). The principal components method was applied to establish and interpret correlations between variables obtained of modulus of elasticity, bending strength and density. The static modulus of elasticity presented higher correlation values than those obtained using non-destructive methods. Bending strength presented low correlations with the non-destructive parameters, but there was some relation to the different knot ratios defined. The relationship was stronger with the most widely used ratio, CKDR. No significant correlations were observed between any of the variables and density.

A review of estimation of distribution algorithms in bioinformatics

Evolutionary search algorithms have become an essential asset in the algorithmic toolbox for solving high-dimensional optimization problems in across a broad range of bioinformatics problems. Genetic algorithms, the most well-known and representative evolutionary search technique, have been the subject of the major part of such applications. Estimation of distribution algorithms (EDAs) offer a novel evolutionary paradigm that constitutes a natural and attractive alternative to genetic algorithms. They make use of a probabilistic model, learnt from the promising solutions, to guide the search process. In this paper, we set out a basic taxonomy of EDA techniques, underlining the nature and complexity of the probabilistic model of each EDA variant. We review a set of innovative works that make use of EDA techniques to solve challenging bioinformatics problems, emphasizing the EDA paradigm's potential for further research in this domain.