Roma Tre University

About: Roma Tre University is a education organization based out in Rome, Lazio, Italy. It is known for research contribution in the topics: Large Hadron Collider & Galaxy. The organization has 4434 authors who have published 15352 publications receiving 374888 citations. The organization is also known as: Universita degli Studi Roma Tre & RomaTre.

Recent tectonic reorganization of the Nubia-Eurasia convergent boundary heading for the closure of the western Mediterranean

Abstract: Key-words. - Western Mediterranean, Convergent boundary, Tectonic reorganization, subduction, Back-arc basin, Basin inversion. Abstract. - In the western Mediterranean area, after a long period (late Paleogene-Neogene) of Nubian (W-Africa) northward subduction beneath Eurasia, subduction has almost ceased, as well as convergence accommodation in the subduction zone. With the progression of Nubia-Eurasia convergence, a tectonic reorganization is therefore necessary to accommodate future contraction. Previously-published tectonic, seismological, geodetic, tomographic, and seismic re- flection data (integrated by some new GPS velocity data) are reviewed to understand the reorganization of the conver- gent boundary in the western Mediterranean. Between northern Morocco, to the west, and northern Sicily, to the east, contractional deformation has shifted from the former subduction zone to the margins of the two back-arc oceanic bas- ins (Algerian-Liguro-Provencal and Tyrrhenian basins) and it is now mainly active in the south-Tyrrhenian (northern Sicily), northern Liguro-Provencal, Algerian, and Alboran (partly) margins. Onset of compression and basin inversion has propagated in a scissor-like manner from the Alboran (c. 8 Ma) to the Tyrrhenian (younger than c. 2 Ma) basins fol- lowing a similar propagation of the cessation of the subduction, i.e., older to the west and younger to the east. It follows that basin inversion is rather advanced on the Algerian margin, where a new southward subduction seems to be in its very infant stage, while it has still to really start in the Tyrrhenian margin, where contraction has resumed at the rear of the fold-thrust belt and may soon invert the Marsili oceanic basin. Part of the contractional deformation may have shifted toward the north in the Liguro-Provencal basin possibly because of its weak rheological properties compared with those of the area between Tunisia and Sardinia, where no oceanic crust occurs and seismic deformation is absent or limited. The tectonic reorganization of the Nubia-Eurasia boundary in the study area is still strongly controlled by the inherited tectonic fabric and rheological attributes, which are strongly heterogeneous along the boundary. These fea- tures prevent, at present, the development of long and continuous thrust faults. In an extreme and approximate synthesis, the evolution of the western Mediterranean is inferred to follow a Wilson Cycle (at a small scale) with the following main steps : (1) northward Nubian subduction with Mediterranean back-arc extension (since ~35 Ma); (2) progressive cessation, from west to east, of Nubian main subduction (since ~15 Ma); (3) progressive onset of compression, from west to east, in the former back-arc domain and consequent basin inversion (since ~8-10 Ma); (4) possible future subduction of former back-arc basins.

A reflection-dominated X-ray spectrum discovered by ASCA in the Circinus galaxy

Abstract: We report the rst pointed X{ray observation, made by ASCA, of the nearby Seyfert 2 galaxy in Circinus. The spectrum consists of a very prominent (EW2 keV) uorescent 6.4 keV iron line, a very at continuum (photon spectral index less than one) and other lines, including one at 7 keV probably due, at least in part, to iron K uorescent emission. The spectrum is consistent with Compton scattering and uorescent emission from cold matter illuminated by an obscured active nucleus.

Composite Indices of Development and Poverty: An Application to MDGs.

Abstract: The measurement of development or poverty as multidimensional phenomena is very difficult because there are several theoretical, methodological and empirical problems involved. The literature of composite indicators offers a wide variety of aggregation methods, all with their pros and cons. In this paper, we propose a new, alternative composite index denoted as MPI (Mazziotta-Pareto Index) which, starting from a linear aggregation, introduces penalties for the countries or geographical areas with ‘unbalanced’ values of the indicators. As an example of application of the MPI, we consider a set of indicators in order to measure the Millennium Development Goals (MDGs) and we present a comparison between HDI (Human Development Index) methodology, HPI (Human Poverty Index) methodology and MPI.