A baseline estimation procedure to improve MDA evaluation in gamma-ray spectrometry

The evaluation of minimum detectable activity (MDA) for a radionuclide in a gamma-ray spectrum is generally carried out through the computation of a suitable background count. This task is sometimes difficult for complex spectra for the presence of many photopeaks which make the trend of continuum extremely variable due to multiple dispersion effects and interference factors. It follows that the MDA assessment must be take into account the contributions of all gamma emissions of radionuclides contained in a sample and its value can be significantly higher than that determined by considering only the background of the spectrometric system due to the overlapping of other peaks. A procedure or an algorithm to determine, each time, the count values to be used for the calculation of MDA is interesting and useful. In this work, some of the more recent algorithms proposed for background subtraction in a gamma-ray spectrum have been examined, applying them in an inverse way for the evaluation of baseline trend in the whole energy range. Among the algorithms examined, particular attention was paid to the application of SNIP (statistical sensitive nonlinear iterative peak clipping) algorithms, which are the simplest to adopt and implement in an application procedure. The results obtained in the analysis of test gamma-ray spectra are satisfactory and allow to quickly determine the MDA values with a formulation based on the ISO-11929 standard

Fuzzy FMECA analysis of radioactive gas recovery system in the SPES experimental facility

Selective Production of Exotic Species is an innovative plant for advanced nuclear physic studies. A radioactive beam, generated by using an UCx target-ion source system, is ionized, selected and accelerated for experimental objects. Very high vacuum conditions and appropriate safety systems to storage exhaust gases are required to avoid radiological risk for operators and people. In this paper, Failure Mode, Effects, and Criticality Analysis of a preliminary design of high activity gas recovery system is performed by using a modified Fuzzy Risk Priority Number to rank the most critical components in terms of failures and human errors. Comparisons between fuzzy approach and classic application allow to show that Fuzzy Risk Priority Number is able to enhance the focus of risk assessments and to improve the safety of complex and innovative systems such as those under consideration

A Spatial Kinetic Model of Crowd Evacuation Dynamics with Infectious Disease Contagion

This paper proposes a kinetic theory approach coupling together the modeling of crowd evacuation from a bounded domain with exit doors and infectious disease contagion. The spatial movement of individuals in the crowd is modeled by a proper description of the interactions with people in the crowd and the environment, including walls and exits. At the same time, interactions among healthy and infectious individuals may generate disease spreading if exposure time is long enough. Immunization of the population and individual awareness to contagion is considered as well. Interactions are modeled by tools of game theory, that let us propose the so-called tables of games that are introduced in the general kinetic equations. The proposed model is qualitatively studied and, through a series of case studies, we explore different scenarios related to crowding and gathering formation within indoor venues under the spread of a respiratory infectious disease, obtaining insights on specific policies to reduce contagion that may be implemented

RELAP5-3D thermal hydraulic analysis of the target cooling system in the SPES experimental facility

The SPES (Selective Production of Exotic Species) experimental facility, under construction at the Italian National Institute of Nuclear Physics (INFN) Laboratories of Legnaro, Italy, is a second generation Isotope Separation On Line (ISOL) plant for advanced nuclear physic studies. The UCx target-ion source system works at temperature of about 2273 K, producing a high level of radiation (10^5 Sv/h), for this reason a careful risk analysis for the target chamber is among the major safety issues. In this paper, the obtained results of thermofluid-dynamics simulations of accidental transients in the SPES target cooling system are reported. The analysis, performed by using the RELAP5-3D 2.4.2 qualified thermal-hydraulic system code, proves good safety performance of this system during different accidental conditions

BCR-ABL residues interacting with ponatinib are critical to preserve the tumorigenic potential of the oncoprotein

Patients with chronic myeloid leukemia in whom tyrosine kinase inhibitors (TKIs) fail often present mutations in the BCR-ABL catalytic domain. We noticed a lack of substitutions involving 4 amino acids (E286, M318, I360, and D381) that form hydrogen bonds with ponatinib. We therefore introduced mutations in each of these residues, either preserving or altering their physicochemical properties. We found that E286, M318, I360, and D381 are dispensable for ABL and BCR-ABL protein stability but are critical for preserving catalytic activity. Indeed, only a "conservative" I360T substitution retained kinase proficiency and transforming potential. Molecular dynamics simulations of BCR-ABLI360T revealed differences in both helix αC dynamics and protein-correlated motions, consistent with a modified ATP-binding pocket. Nevertheless, this mutant remained sensitive to ponatinib, imatinib, and dasatinib. These results suggest that changes in the 4 BCR-ABL residues described here would be selected against by a lack of kinase activity or by maintained responsiveness to TKIs. Notably, amino acids equivalent to those identified in BCR-ABL are conserved in 51% of human tyrosine kinases. Hence, these residues may represent an appealing target for the design of pharmacological compounds that would inhibit additional oncogenic tyrosine kinases while avoiding the emergence of resistance due to point mutations.This work was supported by an investigator grant to P.V. from Associazione Italiana per la Ricerca sul Cancro (AIRC) and by funding from the Biotechnology and Biological Sciences Research Council (BB/I023291/1 and BB/H018409/1 to AP and FF). P.B. is the recipient of an AIRC - Marie Curie fellowship

WikiNEXT: a wiki for exploiting the web of data

International audienceThis paper presents WikiNEXT, a semantic application wiki. WikiNEXT lies on the border between application wikis and modern web based IDEs (Integrated Development Environments) like jsbin.com, jsfiddle.net, cloud9ide.com, etc. It has been initially created for writing documents that integrate data from external data sources of the web of data, such as DBPedia.org or FreeBase.com, or for writing interactive tutorials (e.g. an HTML5 tutorial, a semantic web programming tutorial) that mix text and interactive examples in the same page. The system combines some powerful aspects from (i) wikis, such as ease of use, collaboration and openness, (ii) semantic web/wikis such as making information processable by machines and (iii) web-based IDEs such as instant development and code testing in a web browser. WikiNEXT is for writing documents/pages as well as for writing web applications that manipulate semantic data, either locally or coming from the web of data. These applications can be created, edited or cloned in the browser and can be used for integrating data visualizations in wiki pages, for annotating content with metadata, or for any kind of processing. WikiNEXT is particularly suited for teaching web technologies or for writing documents that integrate data from the web of data

Breve storia del paesaggio

Il paesaggio e l\u2019ecologia sono i temi trainanti del xxi secolo. Presentano valenze e questioni diverse che sono, tuttavia, connesse da intersezioni e interferenze numerose e complesse: l\u2019ecologia fornisce gli strumenti e le regole per attuare le trasformazioni; il paesaggio quelli per rappresentare, previamente, i luoghi trasformati secondo le nuove regole e per confrontarne gli esiti con le configurazioni precedenti; e, ancora, per rilevare eventuali incongruenze originate dalle predizioni e indicare possibili soluzioni alternative. Questo volume origina da tali considerazioni; per sostenere l\u2019idea che il paesaggio non \ue8 solo una questione che riguarda i paesaggisti; per cercare di captare l\u2019attenzione di un pubblico pi\uf9 ampio, sebbene si rivolga soprattutto agli studenti delle facolt\ue0 di Architettura, affinch\ue9 possano dotarsi di uno strumento in pi\uf9 nella redazione dei loro progetti. La storia del paesaggio - breve, come dice il titolo, e fatta in gran parte per immagini - divide il libro con una sezione dedicata al mare, argomento naturale per chi scrive vive e lavora in un\u2019isola, al centro di un mare antico e mitico, temibile e fascinoso e, tuttavia, sconosciuto e, talvolta, non sufficientemente amato