Donsker-Varadhan asymptotics for degenerate jump Markov processes

We consider a class of continuous time Markov chains on a compact metric space that admit an invariant measure strictly positive on open sets together with absorbing states. We prove the joint large deviation principle for the empirical measure and flow. Due to the lack of uniform ergodicity, the zero level set of the rate function is not a singleton. As corollaries, we obtain the Donsker-Varadhan rate function for the empirical measure and a variational expression of the rate function for the empirical flow

A gradient flow approach to linear Boltzmann equations

We introduce a gradient flow formulation of linear Boltzmann equations. Under a diffusive scaling we derive a diffusion equation by using the machinery of gradient flows

Large deviations for Kac-like walks

We introduce a Kac's type walk whose rate of binary collisions preserves the total momentum but not the kinetic energy. In the limit of large number of particles we describe the dynamics in terms of empirical measure and flow, proving the corresponding large deviation principle. The associated rate function has an explicit expression. As a byproduct of this analysis, we provide a gradient flow formulation of the Boltzmann-Kac equation

Stand dynamics of a beech coppice beyond the rotation age and under conversion into high forest.

 One of major issues dealing with forest management in Italy is the lack or the suspension of silvicultural practices over an increased share of the forest area, in progress since a few decades ago. The abandonment of rural areas, the emerging environmental functions being nowadays addressed to natural resources, include also many forests and management systems formerly devoted mainly to wood production. This occurrence has its major evidence on coppice forests, i.e. about a half of the country forest area and the forest type historically submitted to the more intensive management practices. The results of an experimental trial started in 1972 in a beech coppice aged 27, i.e. a few years after the age of traditional rotation, comparing the natural evolutive pattern as well as the silvicultural practices aimed at its conversion into high forest, are here reported. The trial included the control thesis and three different thinning intensities. Each thesis was arranged within the same thinning type, taking into account the volume of former standing crop in each plot. The analysis includes the growth pattern and the dynamics of stand structure in the populations under natural evolution and under conversion into high forest. Four inventories were carried out since 1972 at each decade up to 2002. Three thinnings were undertaken within the same time. Results show that both the tested management options, alternative and/or complementary to the traditional coppice system, are based on reliable biological assumptions. The natural evolutive pattern highlights the growth trend at ages older than those monitored under the coppice system. Beech shows a peculiar behaviour in the range observed due to its specific shade-tolerance. The shoot population reveals a sustained growth between the ages of 30 to 40; then, the occurrence of a heavy, regular mortality up to 50; finally, the recovery of a high growth rate up to the age of 60 (ending of the monitored period at now). Such growth pattern moves up the current volume increment, delays its intersection to mean increment and postpones substantially the age of growth rates culmination. The observed trend deviates from the canonical stand growth pattern and seems to be grounded on beech auto-ecology. This extends the time of reaction between the opposite feedbacks of mortality and growth and allows monitoring a likely different behaviour ruling ageing coppice growth. The same occurrence had not been highlighted before studying light-demanding species (deciduous oaks in the case) under the same stand types, these species being able to settle much more rapidly the cycle mortality-growth recovery-incremental culmination. The thesis of conversion into high forest provides the technical cultivation rules (type, intensity and interval of thinning repetition) and suggests it as enforceable also in the private domain due to the shortly-repeated harvestings and intermediate volumes that make each intervention profitable. The basic outcomes of the applied silvicultural practices are (i) the early crown shaping of shoot dendrotypes; (ii) the modeling of clustered stand structure; (iii) the individual development of well-balanced trees, more suited to tackle the grown-up and mature stages till the time of regeneration from seed, ending of the transitory cycle

Anoplophora chinensis (Forster) (Coleoptera Cerambycidae) in the outbreak site in Rome (Italy): experiences in dating exit holes

Anoplophora chinensis is a poliphagous woodboring beetle native to Eastern Asia, and is a serious pest accidentally introduced into Europe. Currently two infested areas are present in Italy and other infestations have occurred in the past in other European countries, while interceptions in entry ports are made yearly by National Plant Protection Organizations of the European Community. A. chinensis is a quarantine invasive pest, and strong measures are applied worldwide to prevent its introduction, spread and to eradicate its populations. The presence of exit holes of adult beetles on infested trees is one of the most important diagnostic signs to detect an A. chinensis infestation. Exit holes are visible on the bark surface of infested trees for several years, but the hole is after that enclosed by the reaction tissue (callus) of the plant; thus, after some years the exit hole is no longer visible. Such injuries produced by beetle activity can be recognised after many years by inspection of the wood after cross-sectioning of the tree. It is possible to date the time of occurrence of the injury using the annual growth ring method for tree age analyses. Surveys conducted on the wooden material collected in the infested site in Rome indicate that the first A. chinensis adult emergences from infested trees of the city occurred in 2002. Since the species takes in the infested site 1 or 2 years for juvenile development, we can speculate that the first introduction of A. chinensis into the city of Rome took place in the years 2000 or 2001

Changes in management, climate and N deposition explain recent deviation from expected growth in mature Spruce and Beech forests in Italy

A study on the effect of N deposition on tree grwoth in Italian forest

Comparing two permanent plots in Croatia and Italy with different levels of nitrogen deposition

A preliminary comparison between two forest plot with different N load

Indicators of sustainable forest management: application and assessment

Report of the international project Life ManForCBD

Correlazioni tra UHECRs di Auger e neutrini di ANTARES

Questo lavoro ha lo scopo di individuare una strada nella ricerca di un confronto tra canditati eventi di neutrino cosmico da parte dell'esperimento ANTARES ,nel Mar Mediterraneo a sud est della costa di Tolone, in Francia e gli Ultra High Energy Cosmic Rays dell'osservatorio Pierre Auger in Argentina. Si utilizzano dati raccolti dal telescopio di neutrini ANTARES tra il 2007 e il 2013, con energie dell'ordine del TeV, e quelli di Auger ottenuti tra il 2004 e il 2014, con energie dei raggi cosmici dell'ordine dell'EeV. Entrambi gli apparati sono basati sulla rivelazione di radiazione Cherenkov, ma l'osservatorio di Auger è dotato di un secondo rivelatore di luminescenza che lavora in sincrono per ridurre gli errori sistematici associati ai singoli rivelatori. Le distribuzioni degli eventi in base alle direzioni di arrivo e dell' energia osservata, sono i parametri necessari per la ricerca di una correlazione. Dalla sovrapposizione delle distribuzioni possiamo evidenziare le zone di visibilità caratteristiche di ciascun esperimento, e condurre un eventuale successiva analisi finalizzata ad una identificazione univoca di eventi coincidenti