Parameter estimates for fishes of the upper Paraná river floodplain and Itaipu reservoir (Brazil)

Estimates of the growth (K), natural mortality (M), consumption/biomass (Q/B) rate and trophic level (TL) for 35 species in the upper Paraná river floodplain and the Itaipu reservoir (interconnected ecosystems) are presented. A compilation of these biological statistics is made for comparison purposes and some general trends are briefly discussed

Phase diagram of a solution undergoing inverse melting

The phase diagram of $\alpha$-cyclodextrin/water/4-methylpyridine solutions, a system undergoing inverse melting, has been studied by differential scanning calorimetry, rheological methods, and X-rays diffraction. Two different fluid phases separated by a solid region have been observed in the high $\alpha$-cyclodextrin concentration range ($c$$\geq$150 mg/ml). Decreasing $c$, the temperature interval where the solid phase exists decreases and eventually disappears, and a first order phase transition is observed between the two different fluid phases.Comment: 4 pages, 5 figures, accepted on Physical Review E (R

X-ray view of four high-luminosity Swift/BAT AGN: Unveiling obscuration and reflection with Suzaku

The Swift/BAT nine-month survey observed 153 AGN, all with ultra-hard X-ray BAT fluxes in excess of 10^-11 erg cm^-2 s^-1 and an average redshift of 0.03. Among them, four of the most luminous BAT AGN (44.73 < Log L(BAT) < 45.31) were selected as targets of Suzaku follow-up observations: J2246.0+3941 (3C 452), J0407.4+0339 (3C 105), J0318.7+6828, and J0918.5+0425. The column density, scattered/reflected emission, the properties of the Fe K line, and a possible variability are fully analyzed. For the latter, the spectral properties from Chandra, XMM-Newton and Swift/XRT public observations were compared with the present Suzaku analysis. Of our sample, 3C 452 is the only certain Compton-thick AGN candidate because of i) the high absorption and strong Compton reflection; ii) the lack of variability; iii) the "buried" nature, i.e. the low scattering fraction (<0.5%) and the extremely low relative [OIII] luminosity. In contrast 3C 105 is not reflection-dominated, despite the comparable column density, X-ray luminosity and radio morphology, but shows a strong long-term variability in flux and scattering fraction, consistent with the soft emission being scattered from a distant region (e.g., the narrow emission line region). The sample presents high (>100) X-to-[OIII] luminosity ratios, confirming the [OIII] luminosity to be affected by residual extinction in presence of mild absorption, especially for "buried" AGN such as 3C 452. Three of our targets are powerful FRII radio galaxies, making them the most luminous and absorbed AGN of the BAT Seyfert survey despite the inversely proportional N_H - L_X relation.Comment: A&A paper in press, 17 page

Hierarchical Partial Planarity

In this paper we consider graphs whose edges are associated with a degree of {\em importance}, which may depend on the type of connections they represent or on how recently they appeared in the scene, in a streaming setting. The goal is to construct layouts of these graphs in which the readability of an edge is proportional to its importance, that is, more important edges have fewer crossings. We formalize this problem and study the case in which there exist three different degrees of importance. We give a polynomial-time testing algorithm when the graph induced by the two most important sets of edges is biconnected. We also discuss interesting relationships with other constrained-planarity problems.Comment: Conference version appeared in WG201

Laser scanning e photo scanning. Tecniche di rilevamento per la documentazione 3D di beni architettonici ed archeologici

Laser scanner and digital photogrammetric systems (photo scanning) must be considered at present two of the main techniques used for archaeological and architectural surveying. The integration of both 3D scanning systems allowed us to improve the scientific knowledge, the management, the use and the safeguarding of Cultural Heritage. The aim of this article is to identify analogies and differences between the two surveying techniques applied to different archaeological contexts. Starting from a general introduction to the concept of measurement and the management of the data acquired from different techniques of surveying, the article focuses on the laser scanner applications with particular attention on the intrinsic properties of the instrument, the problems of measurement and the methodology used during the survey. The second part is focused on the digital photogrammetry applied on a particular archaeological context. Digital photogrammetry was developed and experimented in order to acquire territorial data quickly. The optimization of the working speed, while maintaining accuracy of data, means cost savings and an optimal use of funds. Our workgroup decided to transfer that methodology to the archaeological excavations of Rome Metro Line C in collaboration with some public institutions and private companies. The final results have produced 2D and 3D graphic documentations of all the archaeological area up to highly-accurate ortho-recti ??ed images. Point clouds allowed us to simultaneously view a general 3D model of all open archaeological areas, providing an opportunity for observation and an analysis not possible by other means. Each area can be studied together with the others in a global view of the excavation. Every stratigraphic unit can be displayed in the same area and switched on in the same way as a layer