Agricoltura e allevamento ovino: orizzonti mediterranei e territori cisalpini

Despite the acknowledged and celebrated width of documentary sources (literary and epigraphic) relating to the commercial and economic importance of the production and processing of wool in the ancient Venetia, the historiographical panorama started to give some attention to the initial phase of this multi steps process, constituted by farming and sheep grazing, only during the last two decades. This recent efforts to tackle the problematic had to cope with the usual reticence of the ancient authors about farming practices in that geographic area and with the lack of archaeological evidence concerning pastoralism. For this reason, scholars often gave prime attention to farming practices typical of Mediterranean regions like central-southern Italy or Spain, and as a result they tended to analyse the farming in northern Italy according to patterns typical of those regions. Consequently there was a tendency to isolate the most characteristic practice of moving livestock, known as transhumance, as only theme of discussion and sole farming practice existing in north Italy. With these preliminary remarks, the contribution aims to re-evaluate the theme of the sheep farming in the regions of the Po Valley on the basis of two unavoidable considerations of methodology. First of all, we want to free the thematic of farming from the forced isolation to which to some extent the scholars relegated it, separating this topic from the economic and productive context of the municipal territories, in order to contextualise it properly into the systemic production and economic dynamics of these ancient lands, in which it was likely to have a dialogic relationship with the practices of agricultural use of soil. Secondly, we want to underline the geographical, climatic and vegetational peculiarity of the Veneto region, which makes it completely different from any other Mediterranean context, and that as such it has to be treated when studying the farming practices, through analysis not related to interpretive models generated in areas affected by different bioclimatic regimes. In conclusion, we will try to suggest a reconstructive scenery of the sheep farming practices in the Po Valley and of the ways they related to the agricultural system, according to the environmental and spatial features typical of the examined region

Properties of Stationary Nonequilibrium States in the Thermostatted Periodic Lorentz Gas II: The many point particles system

We study the stationary nonequilibrium states of N point particles moving under the influence of an electric field E among fixed obstacles (discs) in a two dimensional torus. The total kinetic energy of the system is kept constant through a Gaussian thermostat which produces a velocity dependent mean field interaction between the particles. The current and the particle distribution functions are obtained numerically and compared for small E with analytic solutions of a Boltzmann type equation obtained by treating the collisions with the obstacles as random independent scatterings. The agreement is surprisingly good for both small and large N. The latter system in turn agrees with a self consistent one particle evolution expected to hold in the limit of N going to infinity.Comment: 14 pages, 9 figure

Fluctuation theorem for non-equilibrium relaxational systems driven by external forces

We discuss an extension of the fluctuation theorem to stochastic models that, in the limit of zero external drive, are not able to equilibrate with their environment, extending results presented by Sellitto (cond-mat/9809186). We show that if the entropy production rate is suitably defined, its probability distribution function verifies the Fluctuation Relation with the ambient temperature replaced by a (frequency-dependent) effective temperature. We derive modified Green-Kubo relations. We illustrate these results with the simple example of an oscillator coupled to a nonequilibrium bath driven by an external force. We discuss the relevance of our results for driven glasses and the diffusion of Brownian particles in out of equilibrium media and propose a concrete experimental strategy to measure the low frequency value of the effective temperature using the fluctuations of the work done by an ac conservative field. We compare our results to related ones that appeared in the literature recently.Comment: 39 pages, 6 figure

HCT116 colorectal liver metastases exacerbate muscle wasting in a mouse model for the study of colorectal cancer cachexia

Colorectal cancer (CRC) is often accompanied by formation of liver metastases (LM) and skeletal muscle wasting, i.e. cachexia. Despite affecting the majority of CRC patients, cachexia remains underserved, understudied and uncured. Animal models for the study of CRC-induced cachexia, in particular models containing LM, are sparse; therefore, we aimed to characterize two new models of CRC cachexia. Male NSG mice were injected subcutaneously (HCT116) or intrasplenically (mHCT116) with human HCT116 CRC tumor cells to disseminate LM, whereas experimental controls received saline (n=5-8/group). Tumor growth was accompanied by loss of skeletal muscle mass (HCT116: -20%; mHCT116: -31%; quadriceps muscle) and strength (HCT116: -20%; mHCT116: -27%), with worsened loss of skeletal muscle mass in mHCT116 compared with HCT116 (gastrocnemius: -19%; tibialis anterior: -22%; quadriceps: -21%). Molecular analyses revealed elevated protein ubiquitination in HCT116, whereas mHCT116 also displayed elevated Murf1 and atrogin-1 expression, along with reduced mitochondrial proteins PGC1α, OPA1, mitofusin 2 and cytochrome C. Further, elevated IL6 levels were found in the blood of mHCT116 hosts, which was associated with higher phosphorylation of STAT3 in skeletal muscle. To clarify whether STAT3 was a main player in muscle wasting in this model, HCT116 cells were co-cultured with C2C12 myotubes. Marked myotube atrophy (-53%) was observed, along with elevated phospho-STAT3 levels (+149%). Conversely, inhibition of STAT3 signaling by means of a JAK/STAT3 inhibitor was sufficient to rescue myotube atrophy induced by HCT116 cells (+55%). Overall, our results indicate that the formation of LM exacerbates cachectic phenotype and associated skeletal muscle molecular alterations in HCT116 tumor hosts

Note on the Kaplan-Yorke dimension and linear transport coefficients

A number of relations between the Kaplan-Yorke dimension, phase space contraction, transport coefficients and the maximal Lyapunov exponents are given for dissipative thermostatted systems, subject to a small external field in a nonequilibrium stationary state. A condition for the extensivity of phase space dimension reduction is given. A new expression for the transport coefficients in terms of the Kaplan-Yorke dimension is derived. Alternatively, the Kaplan-Yorke dimension for a dissipative macroscopic system can be expressed in terms of the transport coefficients of the system. The agreement with computer simulations for an atomic fluid at small shear rates is very good.Comment: 12 pages, 5 figures, submitted to J. Stat. Phy

The Nora Virtual Tour: an immersive visit in the ancient city

The ancient city of Nora was a Phoenician, Punic and Roman settlement rising on a peninsula in the south-western coast of Sardinia. Since 1990, the University of Padova has been carrying on an interdisciplinary research project of excavation, architectural analysis, historical reconstruction and cultural promotion of tourism in this site. The excavations allow us to increase our knowledge of Middle Imperial Roman urban planning and to get a better understanding of the whole city and its history; the restoration of excavated monuments using gravels with different colours helps more than 60,000 tourists every year to recognize the function of different areas. In spite of this, visitors experience difficulty in understanding a landscape of ruins with barely visible evidence. Thus, a complete virtual reconstruction of the ancient city has become essential. 3D models of the Phoenician and Roman settlement have been developed, reshaping archaeological plans produced in 25 years by Universities that work in the site. The main monuments of the Roman city and the major crossroads have been rendered in greater detail, using sample-based textures that give a photorealistic effect and implementing the models with furniture and decorations selected through reliable sources of information. 3D reconstructions are now available for tourist groups led by a guide in the Nora Virtual Tour: stereoscopic images have been rendered and uploaded in an app for mobile headsets that provides immersive virtual reality for the users. The guide controls the devices with a tablet using a Bluetooth connection: at the beginning of the visit, the tourists can view equirectangular panoramas of the ruins taken from a helicopter, then they are accompanied to hot-spots where the ancient monuments are shown in an evocative Roman reconstruction

Thermodynamic entropy production fluctuation in a two dimensional shear flow model

We investigate fluctuations in the momentum flux across a surface perpendicular to the velocity gradient in a stationary shear flow maintained by either thermostated deterministic or by stochastic boundary conditions. In the deterministic system the Gallavotti-Cohen (GC)relation for the probability of large deviations, which holds for the phase space volume contraction giving the Gibbs ensemble entropy production, never seems to hold for the flux which gives the hydrodynamic entropy production. In the stochastic case the GC relation is found to hold for the total flux, as predicted by extensions of the GC theorem but not for the flux across part of the surface. The latter appear to satisfy a modified GC relation. Similar results are obtained for the heat flux in a steady state produced by stochastic boundaries at different temperatures.Comment: 9 postscript figure

Propagation of Chaos for a Thermostated Kinetic Model

We consider a system of N point particles moving on a d-dimensional torus. Each particle is subject to a uniform field E and random speed conserving collisions. This model is a variant of the Drude-Lorentz model of electrical conduction. In order to avoid heating by the external field, the particles also interact with a Gaussian thermostat which keeps the total kinetic energy of the system constant. The thermostat induces a mean-field type of interaction between the particles. Here we prove that, starting from a product measure, in the large N limit, the one particle velocity distribution satisfies a self consistent Vlasov-Boltzmann equation.. This is a consequence of "propagation of chaos", which we also prove for this model.Comment: This version adds affiliation and grant information; otherwise it is unchange