Foam formation in lakes: a long term analysis conducted on Lake Maggiore (northern Italy)

The causes and origin of foams in lakes have been rarely object of studies, although this phenomenon may cause problems to touristic or fisheries activities and imply a possible risk to human health. The formation of foams in the aquatic environment is due to the accumulation of surfaceactive compounds (surfactants) at the air-water interface joined with the mechanic action of a forcing (such as wind or waves) able to inject gas bubbles in the upper water layer. Surfactants can be either of natural or synthetic origin. Fulvic or humic acids, lipidic, proteic or colloidal substances are examples of natural surfactants that can promote foam formation, while man-made foams are generally due to the release of phosphates from agriculture and/or to the presence of organic and inorganic detergents. A comprehensive analysis of three foam episodes in Lake Maggiore (2007, 2008 and 2010) has been undertaken to identify their origin, causes and to unravel most likely factors triggering foam formation. At this scope, a long term (2000-2013) analysis of phytoplankton biovolumes and meteorological and hydrological anomalies has been performed together with the chemical characterization of foams. Foam resulted of endogenous origin, related to phytoplankton biomass degradation. The long term analysis highlighted atypical warm temperatures and residual lake stratification in winter in two of the years of foam events, coupled with exceptional Bacillariophyceae blooms in spring. Tabellaria flocculosa mostly contributed in terms of biomass in 2007 and 2008, but not in 2010, and overall total algal biomass seemed a better predictor of the risk of foam formation. Foam events occurred from July to December, driven by atypically high windy conditions, and congruently with the time needed to degrade biomass into surfactant compounds. A co-occurrence of different factors resulted essential to generate foams, and climate changes likely contributed to enhance their occurrence in Lake Maggiore

Surface Plasmon Resonance as a Tool for Ligand Binding Investigation of Engineered GPR17 Receptor, a G Protein Coupled Receptor Involved in Myelination

The aim of this study was to investigate the potential of surface plasmon resonance (SPR) spectroscopy for the measurement of real-time ligand-binding affinities and kinetic parameters for GPR17, a G protein-coupled receptor (GPCR) of major interest in medicinal chemistry as potential target in demyelinating diseases. The receptor was directly captured, in a single-step, from solubilized membrane extracts on the sensor chip through a covalently bound anti-6x-His-antibody and retained its ligand binding activity for over 24h. Furthermore, our experimental setup made possible, after a mild regeneration step, to remove the bound receptor without damaging the antibody, and thus to reuse many times the same chip. Two engineered variants of GPR17, designed for crystallographic studies, were expressed in insect cells, extracted from crude membranes and analyzed for their binding with two high affinity ligands: the antagonist Cangrelor and the agonist Asinex 1. The calculated kinetic parameters and binding constants of ligands were in good agreement with those reported from activity assays and highlighted a possible functional role of the N-terminal residues of the receptor in ligand recognition and binding. Validation of SPR results was obtained by docking and molecular dynamics of GPR17-ligands interactions and by functional in vitro studies. The latter allowed us to confirm that Asinex 1 behaves as GPR17 receptor agonist, inhibits forskolin-stimulated adenylyl cyclase pathway and promotes oligodendrocyte precursor cell maturation and myelinating ability

An Operational Hydro-Meteorological Chain to Evaluate the Uncertainty in Runoff Forecasting over the Verbano Basin

The development and implementation of a real-time flood forecasting system with a hydro-meteorological operational alert procedure during the MAP-D-PHASE Project is described in this paper. This chain includes both probabilistic and deterministic forecasts. The hydrological model used to generate the runoff simulations is the rainfall-runoff distributed FEST-WB model, developed at Politecnico di Milano. The observed data to run the control simulations were supplied by ARPA-Piemonte. The analysis is focused on Maggiore Lake basin, an Alpine basin between North-West of Italy and Southern Switzerland. Two hindcasts during the D-PHASE period are discussed in order to evaluate certain effects regarding discharge forecasts due to hydro-meteorological sources of uncertainties. In particular, in the June convective event it is analysed how the effect of meteorological model spatial resolution can influence the discharge forecasts over mountain basins, while in the November stratiform event how the effect of the initial conditions of soil moisture can modify meteorological warnings. The study shows how the introduction of alert codes appears to be useful for decision makers to give them a spread of forecasted QDFs with the probability of event occurrence, but also how alert warnings issued on the basis of forecasted precipitation only are not always reliable

Electromyographic and biomechanical analysis of step negotiation in Charcot Marie Tooth subjects whose level walk is not impaired

reserved11Background: Charcot-Marie-Tooth (CMT) is a slowly progressive disease characterized by muscular weakness and wasting with a length-dependent pattern. Mildly affected CMT subjects showed slight alteration of walking compared to healthy subjects (HS).Research question: To investigate the biomechanics of step negotiation, a task that requires greater muscle strength and balance control compared to level walking, in CMT subjects without primary locomotor deficits (foot drop and push off deficit) during walking.Methods: We collected data (kinematic, kinetic, and surface electromyographic) during walking on level ground and step negotiation, from 98 CMT subjects with mild-to-moderate impairment. Twenty-one CMT subjects (CMTNLW, normal-like-walkers) were selected for analysis, as they showed values of normalized ROM during swing and produced work at push-off at ankle joint comparable to those of 31 HS. Step negotiation tasks consisted in climbing and descending a two-step stair. Only the first step provided the ground reaction force data. To assess muscle activity, each EMG profile was integrated over 100% of task duration and the activation percentage was computed in four phases that constitute the step negotiation tasks.Results: In both tasks, CMT-NLW showed distal muscle hypoactivation. In addition, during step-ascending CMTNLW subjects had relevant lower activities of vastus medialis and rectus femoris than HS in weight-acceptance, and, on the opposite, a greater activation as compared to HS in forward-continuance. During step-descending, CMT-NLW showed a reduced activity of tibialis anterior during controlled-lowering phase.Significance: Step negotiation revealed adaptive motor strategies related to muscle weakness due to disease in CMT subjects without any clinically apparent locomotor deficit during level walking. In addition, this study provided results useful for tailored rehabilitation of CMT patients.mixedLencioni, T; Piscosquito, G; Rabuffetti, M; Di Sipio, E; Diverio, M; Moroni, I; Padua, L; Pagliano, E; Schenone, A; Pareyson, D; Ferrarin, MLencioni, T; Piscosquito, G; Rabuffetti, M; Di Sipio, E; Diverio, M; Moroni, I; Padua, L; Pagliano, E; Schenone, A; Pareyson, D; Ferrarin,

Flash flood forecasting within the PREVIEW project : value of high-resolution hydrometeorological coupled forecast

PREVIEW is an European Commission FP6 Integrated Project which aims at developing, on an European level, new geo-information services for natural and industrial risk management. The work package WP4340 focuses on forecast of Mediterranean flash floods. Phase 1 was devoted to the assessment of the usefulness of kilometric scale atmospheric model forecast for hydrological applications and to the development of hydro-meteorological coupled systems based on high-resolution atmospheric models and hydrological models able to reproduce the hydrological behaviour of Mediterranean catchments. Four high-resolution models at 2–3 km resolution have been run on five flash-flood cases over the French Cévennes-Vivarais and Italian Piedmont regions; models are MM5 (by NOA), COSMO-2 (by MeteoSwiss), MESO-NH (by Météo-France) and COSMO-LAMI (by Arpa Piemonte). To investigate the benefit of coupling atmospheric and hydrological models, the quantitative precipitation forecasts (QPF) have been verified against observations using both classical and categorical statistical scores, while the sensitivity of the QPF to the model initial conditions has been also examined. In addition, the various hourly precipitation forecasts were supplied as input to hydrological models to evaluate through the simulated discharges the value of high resolution forecasts for hydrological forecast purposes. Clearly the hydrological verification conclusions differ from the QPF verification ones and show the usefulness of developing such hydrological verification as the one performed here