Rock-eating mycorrhizas: their role in plant nutrition and biogeochemical cycles

A decade ago, tunnels inside mineral grains were found that were likely formed by hyphae of ectomycorrhizal (EcM) fungi. This observation implied that EcM fungi can dissolve mineral grains. The observation raised several questions on the ecology of these ¿rock-eating¿ fungi. This review addresses the roles of these rock-eating EcM associations in plant nutrition, biogeochemical cycles and pedogenesis. Research approaches ranged from molecular to ecosystem level scales. Nutrient deficiencies change EcM seedling exudation patterns of organic anions and thus their potential to mobilise base cations from minerals. This response was fungal species-specific. Some EcM fungi accelerated mineral weathering. While mineral weathering could also increase the concentrations of phytotoxic aluminium in the soil solution, some EcM fungi increase Al tolerance through an enhanced exudation of oxalate. Through their contribution to Al transport, EcM hyphae could be agents in pedogenesis, especially podzolisation. A modelling study indicated that mineral tunnelling is less important than surface weathering by EcM fungi. With both processes taken together, the contribution of EcM fungi to weathering may be significant. In the field vertical niche differentiation of EcM fungi was shown for EcM root tips and extraradical mycelium. In the field EcM fungi and tunnel densities were correlated. Our results support a role of rock-eating EcM fungi in plant nutrition and biogeochemical cycles. EcM fungal species-specific differences indicate the need for further research with regard to this variation in functional traits

ANN-based approach for the estimation aquifer pollutant source behaviour

The problem of identifying an unknown pollution source in polluted aquifers, based on known contaminant concentrations measurement, is part of the broader group of issues, called inverse problems. This paper investigates the feasibility of solving the groundwater pollution inverse problem by using artificial neural networks (ANNs). The approach consists first in training an ANN to solve the direct problem, where the pollutant concentration in a set of monitoring wells is calculated for a known pollutant source. Successively, the trained ANN is frozen and it is used to solve the inverse problem, where the pollutant source is calculated which corresponds to a set of concentrations in the monitoring wells. The approach has been applied for a real case which deals with the contamination of the Rhine aquifer by carbon tetrachloride (CCl4) due to a tanker accident. The obtained results are compared with the solution obtained with a different approach retrieved from literature. The results show the suitability of ANNs-based methods for solving inverse non-linear problems

Heavy-ion Physics at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC): Feasibility Studies for Quarkonium and Drell-Yan Production

We outline the case for heavy-ion-physics studies using the multi-TeV lead LHC beams in the fixed-target mode. After a brief contextual reminder, we detail the possible contributions of AFTER@LHC to heavy-ion physics with a specific emphasis on quarkonia. We then present performance simulations for a selection of observables. These show that $\Upsilon(nS)$, $J/\psi$ and $\psi(2S)$ production in heavy-ion collisions can be studied in new energy and rapidity domains with the LHCb and ALICE detectors. We also discuss the relevance to analyse the Drell-Yan pair production in asymmetric nucleus-nucleus collisions to study the factorisation of the nuclear modification of partonic densities and of further quarkonia to restore their status of golden probes of the quark-gluon plasma formation.Comment: 18 pages, 7 figure

FOOD SAFETY AND PROCESS HYGIENE CRITERIONS ON SHEEP CARCASSES

The hygienic status and the presence of some pathogens (Staphylococcus aureus, Listeria monocytogenes e Salmonella spp.) at slaughterhouses was evaluated in different matrix of sheep and lambs (carcass surface, faeces, fleeces and mesenteric lymph nodes) according to the Com. Reg. (EC) No 2073/2005. The 48% of sheep and 68.9% of lamb sampled carcasses resulted allocated into the marginal category for Aerobic colony count, while the 28% and 42.2% respectively were allocated into unacceptable category for Enterobacteriaceae. S.aureus was isolated more frequently in fleeces (11.5%), carcasses (12.6%) of lambs than sheep. L. monocytogenes was found in fleeces and carcass of two sheep and in faeces of four lambs, while Salmonella spp. was detected only in sheep carcasses of a single plant

Heavy-ion Physics at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC): Feasibility Studies for Quarkonium and Drell-Yan Production

We outline the case for heavy-ion-physics studies using the multi-TeV lead LHC beams in the fixed-target mode. After a brief contextual reminder, we detail the possible contributions of AFTER@LHC to heavy-ion physics with a specific emphasis on quarkonia. We then present performance simulations for a selection of observables. These show that $\varUpsilon (nS)$ , $J/\psi$ and $\psi (2S)$ production in heavy-ion collisions can be studied in new energy and rapidity domains with the LHCb and ALICE detectors. We also discuss the relevance to analyse the Drell–Yan pair production in asymmetric nucleus–nucleus collisions to study the factorisation of the nuclear modification of partonic densities and of further quarkonium states to restore their status of golden probes of the quark–gluon plasma formation.Peer Reviewe