Search

A 4 π light charged particle spectrometer, called 8 π LP, is in operation at the Laboratori Nazionali di Legnaro, Italy, for studying reaction mechanisms in low-energy heavy-ion reactions. Besides about 300 telescopes to detect light charged particles, the spectrometer is also equipped with an anular PPAC system to detect evaporation residues and a two-arm time-of-flight spectrometer to detect fission fragments. The spectrometer has been used in several fission dynamics studies using as a probe light charged particles in the fission and evaporation residues (ER) channels. This paper proposes a journey within some open questions about the fission dynamics and a review of the main results concerning nuclear dissipation and fission time-scale obtained from several of these studies. In particular, the advantages of using systems of intermediate fissility will be discussed. [ABSTRACT FROM AUTHOR]

A remarkable increase in knowledge of fungal biodiversity in Italy has occurred in the last five years. The authors report up-to-date numbers of fungi (Basidiomycota and Ascomycota) by regions together with distributional and ecological data on hypogeous fungi. Specific case studies such as alpine fungi, orchid mycorrhizas symbionts, invasive species, and the use of macrofungi as food by red squirrels are analyzed. In situ conservation strategies carried out on target species and/or taxonomic groups are also indicated. [ABSTRACT FROM PUBLISHER]

The aims of this paper were to study the genetic diversity within and among 6 Tuber taxa, the phylogenetic relationships and the spatial distribution of truffles from the Basilicata region (southern Italy). Molecular analyses, using the internal transcribed spacer region, microsatellites, minisatellites and random amplified polymorphic loci revealed the highest expected intra-specific heterozygosity (He=0.30) in T. aestivum, followed by that of T. mesentericum (He=0.22). T. borchii (He=0.17), T. magnatum (He=0.16), T. aestivum fo. uncinatum (He=0.12) and T. brumale fo. moschatum (He=0.09) showed a lower average heterozygosity. The whole set of markers were demonstrated to be useful in clearly differentiating Tuber taxa, separating them in two distinct groups and in five sub-clusters, each corresponding to one single taxon. The first cluster (T. borchii, T. magnatum and T. brumale fo. moschatum) was more differentiated than the second one (T. aestivum, T. aestivum fo. uncinatum and T. mesentericum). T. brumale fo. moschatum was the most differentiated Tuber taxon. It was more related to the white truffles (the closely related T. borchii and T. magnatum) than to the remaining related black truffles T. aestivum and T. mesentericum. The amount of Tuber species richness was higher over the western side of Basilicata, in cold Lauretum and in Castanetum phytoclimatic Pavari's zones. A spatial genetic structure was detected for T. aestivum, as shown by the significant correlation between geographic and genetic distances (rs=0.32; P<0.0001). Integration of molecular and geographic diversity patterns can allow the selection of sites for Tuber and Tuberrelated biodiversity conservation. [ABSTRACT FROM AUTHOR]

Ozone (O3) exposure at Italian background sites exceeds UN/ECE concentration-based critical levels (CLec), if expressed in terms of AOT40. Yet the occurrence of adverse effects of O3 on forests and crops is controversial. Possible reasons include (i) ability of response indicators to provide an unbiased estimate of O3 effects, (ii) setting of current CLec in terms of cut-off value and accumulation level, (iii) response functions adopted to infer a critical level, (iv) environmental limitation to O3 uptake and (v) inherent characteristics of Mediterranean vegetation. In particular, the two latter points suggest that critical levels based on accumulated stomatal flux (CLef) can be a better predictor of O3 risk than CLec. While this concept is largely acknowledged, a number of factors may limit its applicability for routine monitoring. This paper reviews levels, uptake and vegetation response to O3 in Italy over recent years to discuss value, uncertainty and feasibility of different approaches to risk assessment. [Copyright &y& Elsevier]

A virus with filamentous particles was isolated from symptomless plants of Cynara scolymus cvs Romanesco and Terom obtained by in vitro meristem culture in northern Italy. The virus was characterized biologically, physico-chemically and serologically. The cytopathology induced by its infection in two artificial hosts (Chenopodium quinoa and Nicotiana benthamiana) was also investigated. The virus has slightly flexuous elongated particles measuring 12 X 664 nm; its sedimentation coefficient, RNA content, mol. wts. of RNA and coat protein subunits are 150 S, 6%, 2.2 X 10 and 2.9 X 10, respectively. In microprecipitation tests, it resulted serologically related to poplar mosaic virus (popMV) (SDI = 4-5). Cellular inclusions and cytopathology observed in both the artificial hosts conform to those of the carlavirus group. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) fluxes were estimated by three inverse modelling methods over a sorghum field following the application of 240kgNha-1 of urea pills under a semi-arid Mediterranean climate. Ammonia volatilisation started following irrigation, which coincided with the third urea application. The maximum volatilisation rate was reached 7 days after irrigation. A clear dependence of the NH3 volatilisation on irrigation and rainfall events was observed. The NH3 fluxes ranged from -2.5 to 45 μg NH3 m-2 s-1. The canopy compensation point jumped from 9μg NH3 m-3 before urea hydrolysis to 131 μg NH3 m-3 afterwards, while the soil compensation point varied in the meantime from 24 to 800 μg NH3 m-3 on average. The soil-dominated observed NH3 emissions were reasonably well reproduced by a two-layer resistance model. Overall, between 10% and 14% of the total nitrogen applied was volatilised. [ABSTRACT FROM AUTHOR]