Tra natura e artificio. Cartografia storica per lo studio delle trasformazioni del paesaggio di Molentargius

Il contributo propone una lettura diacronica delle trasformazioni del paesaggio, con particolare attenzione alle dinamiche insediative, nell’area di Molentargius a Cagliari, basata sull’analisi di serie storiche di documenti cartografici e aerofotografici. Particolare attenzione è dedicata all’area di Medau Su Cramu – Is Arenas compresa tra lo stagno di Molentargius, le Saline e lo stagno omonimo, che rappresenta un’area di notevole interesse naturalistico e paesaggistico, dovuto anche al particolare ruolo ambientale: da quello di compensazione tra acque dolci (provenienti dall’entroterra) e le acque salate (provenienti dal mare) a quello di habitat semi-naturale per raffinati esemplari di flora e fauna, frammezzato da rilevanti episodi di usi improprio come un vasto campionario di abusi edilizi. L’area oggetto di studio è inserita nell’ambito del “Parco Naturale Regionale del Molentargius – Saline” e sebbene sia sottoposta a vincoli ambientali di elevato tenore giuridico orientato alla tutela, è stata caratterizzata nel recente passato da un rilevante abusivismo edilizio che ha progressivamente alterato la natura dei luoghi, generando un marcato degrado paesaggistico ed ambientale. Lo studio che si intende fornire mediante una prospettiva geo-storica ambientale vuole contribuire al contenimento del consumo di suolo oltreché alla definizione dei margini urbani della città metropolitana di Cagliari. Per fare ciò si condurrà un'analisi dell’evoluzione del paesaggio a diverse scale geografiche e soglie temporali, utilizzando la serie storica delle carte topografiche a partire dalla metà del XIX secolo e altri documenti cartografici d’archivio

Local identity and technological innovation. Urban and territorial policies for the re-interpretation of the historical center of Sadali (Sardinia)

The aim of this study is to propose a technological urban regeneration method by applying innovative techniques of energy conservation to a local stone material of high landscape value, from the historical centre of Sadali (central Sardinia). Basic assumptions for this work are concepts of energy saving in buildings and use of local materials. The two main themes of research are the renovation of existing buildings according to local building materials and construction techniques whilst paying attention to comfort temperature and relative humidity of the building and the complete reconstruction of parts of buildings, or entire buildings, using new techniques and new structural solution, but always using the local stone to respect the building typology

Preparing Teachers with Core Content Expertise to Support Students with Moderate to Severe Disabilities

In this paper, the authors describe a teacher preparation program in the area of moderate to severe disabilities with an emphasis in academic instruction. They present a rationale for their increased focus on academics, a description of the program’s design, and several challenges associated with its implementation. Further, they offer several considerations for iterative improvement of the program

The nature of Composite Seyfert/Star-forming galaxies revealed by X-ray observations

This paper presents new Chandra and BeppoSAX observations aimed at investigating the optical/X-ray mismatch in the enigmatic class of the Composite galaxies, discovered by a cross-correlation of IRAS and ROSAT all sky survey catalogues. These galaxies have been classified as star-forming objects on the basis of their optical spectra, while the detection of weak broad wings in the H(alpha) emission in a few of them and their high X-ray luminosity in the ROSAT band indicated the presence of an active nucleus. The analysis of Chandra observations for 4 Composites has revealed nuclear point-like sources, with a typical AGN spectrum (Gamma = 1.7-1.9) and little intrinsic absorption. A strong flux variability has been observed on different time scales, in particular most of the sources were brighter at the ROSAT epoch. Although of relative low luminosity for the AGN class (L(2-10 keV) = 3-60 x 10^{41} erg/s), the active nucleus is nevertheless dominant in the X-ray domain. At other wavelengths it appears to be overwhelmed by the starburst and/or host galaxy light, yielding the Composite classification for these objects.Comment: 20 pages, 10 figures, accepted by Ap

The clustering of galaxies at z~0.5 in the SDSS-III Data Release 9 BOSS-CMASS sample: a test for the LCDM cosmology

We present results on the clustering of 282,068 galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) sample of massive galaxies with redshifts 0.4<z<0.7 which is part of the Sloan Digital Sky Survey III project. Our results cover a large range of scales from ~0.5 to ~90 Mpc/h. We compare these estimates with the expectations of the flat LCDM cosmological model with parameters compatible with WMAP7 data. We use the MultiDark cosmological simulation together with a simple halo abundance matching technique, to estimate galaxy correlation functions, power spectra, abundance of subhaloes and galaxy biases. We find that the LCDM model gives a reasonable description to the observed correlation functions at z~0.5, which is a remarkably good agreement considering that the model, once matched to the observed abundance of BOSS galaxies, does not have any free parameters. However, we find a deviation (>~10%) in the correlation functions for scales less than ~1 Mpc/h and ~10-40 Mpc/h. A more realistic abundance matching model and better statistics from upcoming observations are needed to clarify the situation. We also estimate that about 12% of the "galaxies" in the abundance-matched sample are satellites inhabiting central haloes with mass M>~1e14 M_sun/h. Using the MultiDark simulation we also study the real space halo bias b(r) of the matched catalogue finding that b=2.00+/-0.07 at large scales, consistent with the one obtained using the measured BOSS projected correlation function. Furthermore, the linear large-scale bias depends on the number density n of the abundance-matched sample as b=-0.048-(0.594+/-0.02)*log(n/(h/Mpc)^3). Extrapolating these results to BAO scales we measure a scale-dependent damping of the acoustic signal produced by non-linear evolution that leads to ~2-4% dips at ~3 sigma level for wavenumbers k>~0.1 h/Mpc in the linear large-scale bias.Comment: Replaced to match published version. Typos corrected; 25 pages, 17 figures, 9 tables. To appear in MNRAS. Correlation functions (projected and redshift-space) and correlation matrices of CMASS presented in Appendix B. Correlation and covariance data for the combined CMASS sample can be downloaded from http://www.sdss3.org/science/boss_publications.ph