Variance bounds for a class of biochemical reactions with bursts using a discrete expansion

We consider the problem of quantifying the variance in the number of molecules of a species, in biochemical reactions with nonlinear reaction rates. We address this problem for a particular configuration where a species is formed with bursts, with a nonlinear rate that depends on another spontaneously formed species. By making use of an appropriately formulated expansion based on the Newton series, in conjunction with spectral properties of the master equation, we derive an analytical expression that provides a hard bound for the variance. We also show that this bound is exact when the propensities are linear. Furthermore, numerical simulations demonstrate that this is very close to the actual variance

Assessment Methods for Sea-Related Hazards in Coastal Areas

Abstract. Italian legislation provides for hazard contingency plans to be prepared by the regional, provincial and local authorities. Despite the extent of damage often caused on the Italian coasts by the action of the sea, sea related hazards have so far been usually ignored; only recently a limited budget in some provinces was allocated for the analysis of risks related to storm damage. The present paper reports on the procedures and the techniques employed and tested within the framework of the provincial contingency plan on the coast of the Salerno province in Italy ( The work was mainly oriented to the evaluation of the potential damage that can be caused by the direct action of waves on coastal areas and on the preparation of hazard maps. The methods and the data that can be used to evaluate the risks are reviewed here, first by rapid examination of the wave field formation offshore and its transformation on shallow water and then by considering the run-up on beaches and infrastructures; the paper is focussed in particular on these latter problems, whichform some point of view -are original and specific to civil protection problems

Large scale coastal storm hazard mapping

Solutions to Coastal Disasters 2002108-11

Wave Run Up and Reflection on Tridimensional Virtual Breakwater

The paper provides some results of a new procedure (CAD and CFD) to analyze the hydrodynamic aspects of the interactions between virtual maritime emerged breakwaters and regular waves. The structure is modeled into numerical domain, very much like the real world or the physical laboratory testing, by overlapping individual three-dimensional elements (AccropodeTM), and the computational grid is fitted so as to provide enough computational nodes within the flow paths. Therefore the filtration of the fluid within the interstices of a concrete blocks breakwater, is evaluated by integrating the Reynolds Averaged Navier-Stokes equations (RANS) inside the voids rather than making use of the “porous media” approach. For the results’ validation, the numerical run-up and reflection effects were compared with some empirical formulas and some similar laboratory tests

Assessment Methods for Sea-Related Hazards in Coastal Areas

Abstract. Italian legislation provides for hazard contingency plans to be prepared by the regional, provincial and local authorities. Despite the extent of damage often caused on the Italian coasts by the action of the sea, sea related hazards have so far been usually ignored; only recently a limited budget in some provinces was allocated for the analysis of risks related to storm damage. The present paper reports on the procedures and the techniques employed and tested within the framework of the provincial contingency plan on the coast of the Salerno province in Italy ( The work was mainly oriented to the evaluation of the potential damage that can be caused by the direct action of waves on coastal areas and on the preparation of hazard maps. The methods and the data that can be used to evaluate the risks are reviewed here, first by rapid examination of the wave field formation offshore and its transformation on shallow water and then by considering the run-up on beaches and infrastructures; the paper is focussed in particular on these latter problems, whichform some point of view -are original and specific to civil protection problems