Butterflies as bioindicators of metal contamination

Anthropogenic trace metal contamination has significantly increased and has caused many hazardous consequences for the ecosystems and human health. The Terni basin valley (Central Italy) shows a heavy load of pollutants from industrial activities, while the characteristic orography structure of the valley favours air stagnation, thus limiting air pollution dispersal. The present study conducted in 2014 aimed to determine the concentration of ten metals in five species of butterflies at nine sites in the Terni valley along a 21-km-long transect, including both relatively pristine and industrial areas. At sites where soil contamination was high for a given metal, such as for chromium as in the case of site 4 (the closest to the steel plant) and for lead as in the case of site 2 (contaminated by a firing range), higher levels of contamination were observed in the tissues of butterflies. We found a correlation between soil contamination and the concentration of Cr, Al and Sr in the tissues of some species of butterflies. The sensitivity to contamination differed among the five species; in particular, Coenonympha pamphilus was generally the species that revealed the highest concentrations of all the ten trace metals at the sites closer to the industrial area. It is known that C. pamphilus is a sedentary species and that its host plants are the Poaceae, capable of accumulating high quantities of metals in their rhizosphere region, thus providing the link with soil contamination. Therefore, monitoring the metal concentration levels in butterflies might be a good indicator and a control tool of environmental quality, specifically in areas affected by high anthropogenic pollution loads linked to a specific source

The impact of xylem geometry on olive cultivar resistance to Xylella fastidiosa: an image‐based study

Xylella fastidiosa is a xylem-limited plant pathogen infecting many crops globally and is the cause of the recent olive disease epidemic in Italy. One strategy proposed to mitigate losses is to replant susceptible crops with resistant varieties. Several genetic, biochemical and biophysical traits are associated to X. fastidiosa disease resistance. However, mechanisms underpinning resistance are poorly understood. We hypothesize that the susceptibility of olive cultivars to infection will correlate to xylem vessel diameters, with narrower vessels being resistant to air embolisms and having slower flow rates limiting pathogen spread. To test this, we scanned stems from four olive cultivars of varying susceptibility to X. fastidiosa using X-ray computed tomography. Scans were processed by a bespoke methodology that segmented vessels, facilitating diameter measurements. Though significant differences were not found comparing stem-average vessel section diameters among cultivars, they were found when comparing diameter distributions. Moreover, the measurements indicated that although vessel diameter distributions may play a role regarding the resistance of Leccino, it is unlikely they do for FS17. Considering Young–Laplace and Hagen–Poiseuille equations, we inferred differences in embolism susceptibility and hydraulic conductivity of the vasculature. Our results suggest susceptible cultivars, having a greater proportion of larger vessels, are more vulnerable to air embolisms. In addition, results suggest that under certain pressure conditions, functional vasculature in susceptible cultivars could be subject to greater stresses than in resistant cultivars. These results support investigation into xylem morphological screening to help inform olive replanting. Furthermore, our framework could test the relevance of xylem geometry to disease resistance in other crops

A portable γ spectroscopy detector for didactic applications

A γ spectroscopy standard system is normally based on inorganic scintillators or on HPGe detectors. The electronic chain consists of a set of NIM mod- ules necessary for the acquisition and processing of the analog signal. The structural characteristics and the complexity of the traditional system make it unsuitable for field measurements and for experiments in high schools. This contribution will de- scribe a compact and portable setup based on a CsI:Tl scintillating crystal readout by a photomultiplier tube, and will demonstrate that the performance of a commer- cial DAQ board is comparable with that of the standard electronic chain, using a NaI:Tl detector in both measures. The limited power consumption, the low cost and the small size make it a versatile and suitable alternative for educational activities both for the nuclear physics lab of the Physics Bachelor’s degree and for dedicated activities in high schools

Catchment compatibility via copulas: A non-parametric study of the dependence structures of hydrological responses

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Diastereoselective Synthesis of Secondary Propargylamines Exploiting CuI-Based Promoters and Determination of Their Relative Configuration by DFT-GIAO Conformational Analysis

The stereoselective synthesis of several secondary propargylamines by the copper-promoted A(3)-coupling reaction of aliphatic and aromatic aldehydes with phenylacetylene and (R)-(+)-phenylethyl-amine is here reported. Two different synthetic methodologies have been investigated in this study, involving CuSO4/NaI and CeCl(3)middot7H(2)O/CuI promoting systems. The reported methodologies were compared in terms of efficiency, diastereoselectivity, and toxicity, both showing advantages with respect to the current methodologies. The relative configurations of each of the obtained propargylamines, previ-ously unknown in the literature, were assigned by comparison of the H-1 NMR experimental chemical shifts with those theoretically predicted via the DFT-GIAO method

Cosmic IT: A portable cosmic ray detecto

Cosmic ray detectors represent an interesting tool for the didactics of modern physics. The Cosmic it detector, designed by the INSULAB group, is a fully portable detector assembled inside a lightweight suitcase. It consists of three modules of plastic scintillator bars, which operate in coincidence. The electronics chain allows measuring the arrival time and the time over threshold (TOT) of the signal generated by each scintillator module, which could be used to retrieve the deposited energy. In this paper we briefly present the basic structure of the detector along with the result of data taking on a private DA40ng light airplane