Reconstruction of a piecewise constant conductivity on a polygonal partition via shape optimization in EIT

In this paper, we develop a shape optimization-based algorithm for the electrical impedance tomography (EIT) problem of determining a piecewise constant conductivity on a polygonal partition from boundary measurements. The key tool is to use a distributed shape derivative of a suitable cost functional with respect to movements of the partition. Numerical simulations showing the robustness and accuracy of the method are presented for simulated test cases in two dimensions

Osservazioni sul mutamento del significato dell'applicazione dei principi del diritto privato all'azione amministrativa alla luce dei recenti sviluppi del diritto pubblico, e sulla sua problematicità

I recenti sviluppi del diritto pubblico impongono una rimeditazione del favore per l’applicazione dei principi del diritto privato all’azione amministrativa.Vi sono infatti aspetti della medesima che rimangono irriducibili ai principi del diritto privato (risarcimento del danno da lesione dell’interesse legittimo, quanto meno rispetto ad alcuni dei suoi profili; procedure di affidamento dei contratti pubblici; reclutamento del personale, ecc.).Pare venire meno quella che sembra essere la giustificazione più razionale dell’applicazione dei principi del diritto privato ai procedimenti amministrativi (e quindi all’azione amministrativa): manca un infatti sistema di valori che possa dirsi da tutti condiviso e viene pertanto meno l’individuazione dei principi del diritto privato come espressione necessaria della maniera più razionale di impostare i rapporti giuridici tra soggetti differenti.  Il Giudice amministrativo ha una sensibilità diversa da quella del Giudice ordinario e quindi la sua applicazione del principio di diritto privato all’Amministrazione è filtrata attraverso tale sensibilità.   Non è tanto l’applicazione dei principi del diritto privato che pare rilevare, quanto piuttosto che la disciplina scelta sia almeno razionale (privatistica o pubblicistica che sia)

Ancient DNA from speleothems: opportunity or challenge?

Ancient environmental DNA retrieved from sedimentary records (sedaDNA) can complement fossil-morphological approaches for characterizing Quaternary biodiversity changes. PCR-based DNA metabarcoding is so far the most widely used method in environmental DNA studies, including sedaDNA. However, degradation of ancient DNA and potential contamination, together with the PCR amplification drawbacks, have to be carefully considered. Here we tested this approach on speleothems from an Alpine cave that, according to a previous palynomorphological study, have shown to contain abundant pollen grains. This offers a unique opportunity for comparing the two methods and, indirectly, trying to validate DNA-based results. The plant taxa identified by sedaDNA are fewer than those by pollen analysis, and success rate of PCR replicates is low. Despite extensive work performed following best practice for sedaDNA, our results are suboptimal and accompanied by a non-negligible uncertainty. Our preliminary data seem to indicate that paleoenvironmental DNA may be isolated from speleothems, but the intrinsic weakness of PCR-based metabarcoding poses a challenge to its exploitation. We suggest that newly developed methods such as hybridization capture, being free from PCR drawbacks and offering the opportunity to directly assess aDNA authenticity, may overcome these limitations, allowing a proper exploitation of speleothems as biological archive

Comparative spectroscopic and electrochemical study of N-1 or N-2-alkylated 4-nitro and 7-nitroindazoles

Abstract Our research groups are by long time involved in the study of the reactivity and the pharmacological activity of nitrogen-containing heterocyclic compounds: in this line we have now examined the behaviour of some substituted 4- and 7-nitroindazoles. Considering the fact that nitroreduction processes are often essential steps for the biological activity of nitro compounds and remembering that some nitroindazoles show interesting biological activities, we have collected nuclear magnetic resonance, electron spin resonance, and cyclic voltammetry data and carried out density functional theory computations on the above compounds thus obtaining an accurate picture of electronic distribution and reduction processes of the examined substrates as a function of their chemical structure. Looking also to our previous results obtained examining the behaviour of 5- and 6-nitroindazoles, we have confirmed the different general behaviour of 1- and 2-alkyl substituted nitroindazoles strictly related to the known different electronic distribution in these two classes of compounds. Interestingly, cyclic voltammetry data have confirmed the ability of N-1 H nitroindazoles to give rise to the formation of dimers, already observed by us studying 5- and 6-nitroindazoles

A validated protocol for eDNA-based monitoring of within-species genetic diversity in a pond-breeding amphibian

In light of the dramatic decline in amphibian biodiversity, new cost-efficient tools to rapidly monitor species abundance and population genetic diversity in space and time are urgently needed. It has been amply demonstrated that the use of environmental DNA (eDNA) for single-species detection and characterization of community composition can increase the precision of amphibian monitoring compared to traditional (observational) approaches. However, it has been suggested that the efficiency and accuracy of the eDNA approach could be further improved by more timely sampling; in addition, the quality of genetic diversity data derived from the same DNA has been confirmed in other vertebrate taxa, but not amphibians. Given the availability of previous tissue-based genetic data, here we use the common frog Rana temporaria Linnaeus, 1758 as our target species and an improved eDNA protocol to: (i) investigate differences in species detection between three developmental stages in various freshwater environments; and (ii) study the diversity of mitochondrial DNA (mtDNA) haplotypes detected in eDNA (water) samples, by amplifying a specific fragment of the COI gene (331 base pairs, bp) commonly used as a barcode. Our protocol proved to be a reliable tool for monitoring population genetic diversity of this species, and could be a valuable addition to amphibian conservation and wetland management

MIRTO: an open-source robotic platform for education

This paper introduces the MIddlesex RoboTic platfOrm (MIRTO), an open-source platform that has been used for teaching First Year Computer Science students since the academic year 2013/2014, with the aim of providing a physical manifestation of Software Engineering concepts that are often delivered using only abstract or synthetic case studies. In this paper we provide a detailed description of the platform, whose hardware specifications and software libraries are all released open source; we describe a number of teaching usages of the platform, report students’ projects, and evaluate some of its aspects in terms of effectiveness, usability, and maintenance

Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an Octocopter

An in-situ calibration of a logarithmic periodic dipole antenna with a frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of a radio station system used for detection of cosmic ray induced air showers at the Engineering Radio Array of the Pierre Auger Observatory, the so-called Auger Engineering Radio Array (AERA). The directional and frequency characteristics of the broadband antenna are investigated using a remotely piloted aircraft (RPA) carrying a small transmitting antenna. The antenna sensitivity is described by the vector effective length relating the measured voltage with the electric-field components perpendicular to the incoming signal direction. The horizontal and meridional components are determined with an overall uncertainty of 7.4^{+0.9}_{-0.3} % and 10.3^{+2.8}_{-1.7} % respectively. The measurement is used to correct a simulated response of the frequency and directional response of the antenna. In addition, the influence of the ground conductivity and permittivity on the antenna response is simulated. Both have a negligible influence given the ground conditions measured at the detector site. The overall uncertainties of the vector effective length components result in an uncertainty of 8.8^{+2.1}_{-1.3} % in the square root of the energy fluence for incoming signal directions with zenith angles smaller than 60{\deg}.Comment: Published version. Updated online abstract only. Manuscript is unchanged with respect to v2. 39 pages, 15 figures, 2 table

Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory

We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to $80^\circ$ and energies in excess of 4 EeV ($4 \times 10^{18}$ eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding $p$-values obtained after accounting for searches blindly performed at several angular scales, are $1.3 \times 10^{-5}$ in the case of the angular power spectrum, and $2.5 \times 10^{-3}$ in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.Comment: Published version. Added journal reference and DOI. Added Report Numbe

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO