The local Galactic magnetic field in the direction of Geminga

The Milagro hot spot A, close to the Galactic anticenter direction, has been tentatively attributed to cosmic rays from a local reservoir (at a distance ~100 pc), freely streaming along diverging and smooth magnetic field lines. This is at variance with the geometry of the ~kpc scale Galactic magnetic field, which is known to be aligned with the spiral arms. We investigate the information available on the geometry of the magnetic field on the scales (~100 pc) of relevance here. The magnetic field immediately upstream of the heliosphere has been investigated by previous authors by modeling the interaction of this field with the solar wind. At larger distances, we use the dispersion measure and the rotation measure of nearby pulsars (especially towards the third Galactic quadrant). Additional information about the local field towards the North Polar Spur is taken from previous studies of the diffuse radio emission and the polarization of starlight. The asymmetry of the heliosphere with respect to the incoming interstellar medium implies a magnetic field almost orthogonal to the local spiral arm, in the general direction of hot spot A, but more to the south. This is in good agreement with the nearby pulsar data on the one side, and the North Polar Spur data on the other. The local magnetic field on scales of ~100 parsecs around the Sun seems to be oriented so as to provide a direct connection between the Solar system and a possible site of the Geminga supernova; the residual angular difference and the shape and orientation of the Milagro hot spot can be attributed to the field trailing in the wake of the heliosphere.Comment: 5 pages, 3 figures, accepted for publication in Astronomy and Astrophysic

UWG -TRNSYS Simulation Coupling for Urban Building Energy Modelling

This paper presents a new methodology to carry out building performance simulation at the district scale integrating the building thermal model TRNSYS with the climate model ‘Urban Weather Generator’ (UWG). The integrated methodology is designed to include the microclimatic modifications induced by urban environments on buildings’ cooling load calculation. The impact of shadows, air temperature increase and urban radiant environment on building cooling performance has been highlighted for hot arid climates (Antofagasta, Chile). Results indicate that the impact of urban context on energy performance of buildings at the neighbourhood scale varies significantly with building typology and urban tissue densit

Mediterranean Desertification and the Economic System

This paper reviews the role of market, population growth, social issues, developmental policies, and other (minor) economic variables contributing to Mediterranean desertification. These variables were classified as describing the micro-economic and macro-economic factors suitable to assure a better comprehension of the environmental-economic nexus. Micro-economic factors like the higher prices and lower wages in the primary sector, as well as the reduction of off-farm employment reflect some potential causes of LD. It was also argued how technical change, agricultural input prices, and household income may affect land vulnerability but their contribution to this ecological problem is poorly known. On the contrary, the role of macroeconomic factors such as population density, poverty, and environmental policies, although more extensively studied on a qualitative base, was regarded as important but still relatively ambiguous, and needs further quantitative studies. Territorial disparities in land distribution, as well as increasing rural poverty and unsustainable management of soil and water were described as a consequence of the process triggering Mediterranean desertification. The effectiveness of policies aimed at mitigating LD and thus reducing desertification risk was finally discussed.Land degradation, desertification, economic system, micro-economic causes, macro-economic factors, Mediterranean basin

‘Interrupted’ landscapes: post-earthquake reconstruction in between urban renewal and social identity of local communities

Il presente saggio vuole affrontare il tema della ricostruzione postsismica con un'attenzione alla questione del paesaggio, termine che lega in maniera indissolubile la realtà fisica del territorio a quei valori immateriali (storici, culturali, produttivi, enogastronomici, ecc.) che costituiscono l'identità dei luoghi. In questo senso si intendono “paesaggi interrotti” i luoghi distrutti dal sisma, perchè sono state interrotte le storie che legano gli abitanti al luogo, è stato interrotto quel processo di narrazione continua e di attribuzione di senso e significati che avviene tra una collettività e il suo territorio. La ricerca parte dall'analisi delle recenti ricostruzioni post-sistmiche, che hanno oscillato tra le due idee opposte di new town, poco distanti dalle città distrutte e ricostruzione “dov'era, com'era”. Il saggio indaga la dimensione sociale e semiologica del paesaggio, riflettendo sul tema dell'identità sociale, sull'attaccamento al luogo da parte degli abitanti, anche con l'obiettivo di definire linee guida e strategie progettuali per la ricostruzione sostenibile dei paesi distrutti dal sisma e da altri eventi disastrosi. In particolare vengono definite azioni di governance, strategie resilienti a partire dal coinvolgimento delle comunità locali e buone pratiche per la ricostruzione secondo un approccio paesaggistico al progetto urbano

Using models to model-check recursive schemes

We propose a model-based approach to the model checking problem for recursive schemes. Since simply typed lambda calculus with the fixpoint operator, lambda-Y-calculus, is equivalent to schemes, we propose the use of a model of lambda-Y-calculus to discriminate the terms that satisfy a given property. If a model is finite in every type, this gives a decision procedure. We provide a construction of such a model for every property expressed by automata with trivial acceptance conditions and divergence testing. Such properties pose already interesting challenges for model construction. Moreover, we argue that having models capturing some class of properties has several other virtues in addition to providing decidability of the model-checking problem. As an illustration, we show a very simple construction transforming a scheme to a scheme reflecting a property captured by a given model.Comment: Long version of a paper presented at TLCA 201

On the image of code polynomials under theta map

The theta map sends code polynomials into the ring of Siegel modular forms of even weights. Explicit description of the image is known for $g\leq 3$ and the surjectivity of the theta map follows. Instead it is known that this map is not surjective for $g\geq 5$. In this paper we discuss the possibility of an embedding between the associated projective varieties. We prove that this is not possible for $g\geq 4$ and consequently we get the non surjectivity of the graded rings for the remaining case $g=4$