Analysis of the optical background sources in the ANTARES experiment and preliminary studies related to a larger scale detector

Il lavoro di tesi presentato si svolge nell'ambito dell'esperimento ANTARES, che prevede la costruzione nel Mediterraneo di un telescopio per la rivelazione di neutrini da sorgenti astrofisiche e mantiene una collaborazione con altri settori della scienza che studiano le profondità del mare. Il telescopio sfrutterà l'acqua del mare come mezzo Cherenkov per rivelare le particelle cariche prodotte dall'interazione dei neutrini con il mare stesso (o il fondale), e rivelerà la luce emessa tramite un array di fotomoltiplicatori distribuiti su dodici stringhe immerse a 2.4 km di profondità. L'energia di soglia per la ricostruzione di un evento è stimata intorno a 50 GeV e si calcola che la massima superficie efficace del telescopio sia dell'ordine di 0.1 km^2. Sorgenti di fondo per l'esperimento sono i neutrini e i muoni atmosferici, ma è presente anche un " fondo ottico" costituito dalla bioluminescenza e dalla luce Cherenkov risultante dai prodotti di decadimenti radioattivi dell'isotopo 40K presente nell'acqua. In questo lavoro di tesi è affrontato il problema del fondo ottico dell'esperimento, in particolar modo è stata effettuata un'analisi delle caratteristiche del fondo da bioluminescenza a partire dai dati disponibili grazie all'ultima stringa di test dell'esperimento, la Prototype Sector Line. Una migliore comprensione del fondo può aiutare ad ottimizzare gli algoritmi di trigger per ridurre il tempo morto del detector o aumentare l'efficacia della selezione. L'analisi presentata individua i parametri utili per simulare in maniera appropriata il fondo e valuta l'accuratezza delle simulazioni ora disponibili. La stessa analisi presenta inoltre interessanti risvolti nell'ambito della biologia, in quanto permette di estrarre informazioni sulla fauna bioluminescente del Mediterraneo, fino ad ora poco studiata. In vista dell'estensione dell'esperimento ad una fase ancora più promettente, con un telescopio dal volume sensibile dell'ordine del km^3, è stato inoltre tentato uno studio preliminare sulle potenzialità di un nuovo tipo di rivelatore di luce, l'Hybrid PhotoDiode (HPD), in sostituzione dei classici fotomoltiplicatori. Mediante un programma di simulazione dell'ottica elettronica è stato riprodotto un possibile modello di HPD in grado di soddisfare i requisiti dell'esperimento. I risultati di tale simulazione sono stati poi introdotti nel Monte Carlo dell'esperimento, per quantificarne (benché grossolanamente) gli effetti sulla ricostruzione degli eventi

Development of a positron emission tomograph for “in-vivo” dosimetry in hadrontherapy

This thesis is related to the DoPET project, which aims to evaluate the feasibility of a dedicated Positron Emission Tomograph (PET) for measuring, monitoring, and verifying the radiation dose that is being delivered to the patient during hadrontherapy. Radiation therapy with protons and heavier ions is becoming a more common treatment option, with many new centers under construction or at planning stage worldwide. The main physical advantage of these new treatment modalities is the high selectivity in the dose delivery: very little dose is deposited in healthy tissues beyond the particles’ range. However, in clinical practice the beam path in the patient is not exactly known. This affects the quality of the treatment planning, and may compromise the translation of the physical advantage into a clinical benefit. The use of a PET system immediately after the therapeutical irradiation (“in-beam”) for in-vivo imaging of the tissue + activation produced by nuclear reactions of the ion beam with the target, could help to have a better control of the treatment delivery. The DoPET project, based on an Italian INFN collaboration, aims to explore one possible approach to the hadron-driven PET technique, through the development of a dedicated device. Such goal was reached through the validation of a PET prototype with proton irradiations on plastic phantoms at the CATANA proton therapy facility (LNS-INFN, Catania, Italy) and with carbon irradiations on plastic phantoms at the GSI synchrotron (Darmstadt, Germany). A preliminary comparison with an existing in-beam PET device was also performed. The candidate was involved with all aspects of this project, specifically the Monte Carlo simulations of the physical processes at the basis of phantom activation, the measurements for the characterization of the DoPET detector, the improvement of the image reconstruction algorithm, and the extensive measurements in plastic phantoms. The system and the methods described in this thesis have to be considered as a proof of principle, and the promising results justify a larger effort for the construction of a clinical system

Operational atlas of exposed mortars and conglomerates for interventions on the widespread architectural heritage

When it comes to Science Heritage, the availability of refined investigation techniques, an advanced knowledge of the characteristics of materials, the current technological capacity and the synergy of specialised operators, coordinated into multidisciplinary teams, guarantee, with the support of cutting-edge tools, excellent results for every conservative operation applied to monumental buildings of acknowledged interest. On the contrary, there are still strong limits to the likelihood that this excellence will reverberate on the multitude of interventions performed on widespread architectural heritage. The research project underway envisages the preparation of an operational atlas of reference for exposed mortars and conglomerates, based on the historical and technological knowledge of materials (particularly those available locally) complete with experimental data on constitution and performance, which is useful to support the development of compatible maintenance and conservation procedures

Digital image correlation applied to lime-based mortars: Shrinkage tests for durability evaluations in restoration works.

Repair mortars applied to architectural heritage buildings for preservation, maintenance, restoration, and strengthening must be carefully studied regarding the many different compatibility issues. In the case of repair interventions, two closely related aspects are especially important: the mortar composition, and the method of its application, which can strongly influence the shrinkage phenomena during the setting and hardening phases. The aim of present experimental research is to set-up a procedure by Digital Imaging Correlation (DIC) technique to deepen shrinkage phenomena in lime-based mortars, thus comparing many different materials, wrongly considered to be similar in behaviour. The technique enable not only shrinkage measurement accuracy higher than standard tests, but also to understand its mechanisms of evolution over time, by evaluating locally strain stress before micro-crack appearing. The interpretation of a large number of test results represents a significant contribution to the development of operational tools to address material selection in specific contexts

Architectural survey, realized with integrated methodology, of the complex of Walser houses in Alagna Valsesia, Italy

[EN] The subject of this paper is the architectural survey, realized with integrated methodology, of three Wal-ser houses, located in Ronco Superiore, within the Alagna Valsesia (Vercelli, Italy) municipality. The task of surveying the complex was assigned to us by the Superintendence of Archeology, Fine Arts and Land-scape for the provinces of Biella, Novara, Verbano-Cusio-Ossola and Vercelli in cooperation with the Regional Secretariat of Piemonte. The aim of the work was that of providing graphic and metric refer-ences for the houses, which are a typical example of the rural architecture at the foot of Monte Rosa, to be made available for subsequent interventions of restoration and enhancement. The Superintendence took over the safekeeping of the site from the Public Property in 1998 and, since then, has promoted a process of recovery of the buildings, winning the Europa Nostra Award in 2014. Granting access to visi-tors has given a larger audience the possibility of knowing the history, the constructive peculiarities and the works of conservation carried out in this area. Specifically, the complex of Walser houses is the most ancient settlement in Alagna, built between the end of XVI century and the beginning of XVII century. Walser houses have a stone basement and wooden roof and walls. The latter are built with the Blockbau technique, i.e. a superimposition of trunks and beams, juxtaposed to shape walls; interlocking connec-tions ensure the rigidity of the structure. First, we have acquired the morphometric characteristics of the buildings; then, we have elaborated them graphically, by employing a georeferenced, 3D laser scanner. Photogrammetric data have, instead, been acquired using digital cameras and drones.Di Paola, A.; Vecchio, S.; Frosini, G.; Verona, B.; Garuglieri, S. (2022). Architectural survey, realized with integrated methodology, of the complex of Walser houses in Alagna Valsesia, Italy. Editorial Universitat Politècnica de València. 95-102. https://doi.org/10.4995/HERITAGE2022.2022.151299510

Stigma in the context of schools: analysis of the phenomenon of stigma in a population of university students

Background Students have stereotyped views about people with mental illness. In particular, they believe that these persons are incurable, dangerous, unpredictable and responsible for their condition. This study aims to investigate the levels of public stigma in an Italian university population. Methods The Attribution Questionnaire 27 - Italian Version (AQ-27-I) was administered to a sample of students from the Faculty of Medicine and Surgery of the University of Modena and Reggio Emilia. After examining the psychometric characteristics of the AQ-27-I (Cronbach’s Alpha and Confirmatory Factor Analysis), multiple linear regression analyses were carried out to identify the predictors of stigmatizing attitudes in this population. Results Three hundred and eleven students completed the questionnaire, with a response rate of 32.81 % (out of the 948 contacted by email). The AQ-27-I showed good psychometric properties with an α = .68, and the fit indices of the models that partially supported the factor structure and paths. The two variables identified as possible predictors of stigmatizing attitudes (total score of AQ-27-I) were age and time spent reading newspapers. Conclusions Antistigma campaigns are needed in university contexts, targeted in particular to students in health professions

Prethymic cytoplasmic CD3 negative acute lymphoblastic leukemia or acute undifferentiated leukemia: a case report

Acute undiffentiated leukemia (AUL) is an acute leukemia with no more than one membrane marker of any given lineage. Blasts often express HLA-DR, CD34, and/or CD38 and may be positive for terminal deoxynucleotidyl transferase (TdT). The expression of CD34, HLA-DR, and CD38 has been shown in pro-T-ALL, although in this case, blasts should also express CD7 and cyCD3. However, some cases of T-ALL without CD3 in the cytoplasm and all TCR chain genes in germ line configuration are reported, features that fit well with a very early hematopoietic cell. We report a case of acute leukemia CD34+/-HLADR+CD7+CD38+cyCD3- in which a diagnosis of AUL was considered. However the blasts were also positive for CD99 and TCR delta gene rearrangement which was found on molecular studies. Therefore a differential diagnosis between AUL and an early cyCD3 negative T-ALL was debated

Prethymic Cytoplasmic CD3 Negative Acute Lymphoblastic Leukemia or Acute Undifferentiated Leukemia: A Case Report

Acute undiffentiated leukemia (AUL) is an acute leukemia with no more than one membrane marker of any given lineage. Blasts often express HLA-DR, CD34, and/or CD38 and may be positive for terminal deoxynucleotidyl transferase (TdT). The expression of CD34, HLA-DR, and CD38 has been shown in pro-T-ALL, although in this case, blasts should also express CD7 and cyCD3. However, some cases of T-ALL without CD3 in the cytoplasm and all TCR chain genes in germ line configuration are reported, features that fit well with a very early hematopoietic cell. We report a case of acute leukemia CD34+/−HLADR+CD7+CD38+cyCD3− in which a diagnosis of AUL was considered. However the blasts were also positive for CD99 and TCR delta gene rearrangement which was found on molecular studies. Therefore a differential diagnosis between AUL and an early cyCD3 negative T-ALL was debated

Binding of a type 1 RIP and of its chimeric variant to phospholipid bilayers: evidence for a link between cytotoxicity and protein/membrane interactions

Ribosome-inactivating proteins (RIPs) are enzymes, almost all identified in plants, able to kill cells by depurination of rRNAs. Recently, in order to improve resistance to proteolysis of a type 1 RIP (PD-L4), we produced a recombinant chimera combining it with a wheat protease inhibitor (WSCI). Resulting chimeric construct, named PD-L4UWSCI, in addition to present the functions of the two domains, shows also an enhanced cytotoxic action on murine cancer cells when compared to PD-L4. Since different ways of interaction of proteins with membranes imply different resulting effects on cells, in this study we investigate conformational stability of PD-L4 and PD-L4UWSCI and their interaction with membrane models (liposomes). Circular dichroism analysis and differential scanning calorimetry measurements indicate that PD-L4 and PD-L4UWSCI present high and similar conformational stability, whereas analysis of their binding to liposomes, obtained by isothermal titration calorimetry and differential scanning calorimetry, clearly indicate that chimera is able to interact with biomembranes more effectively. Overall, our data point out that WSCI domain, probably because of its flexibility in solution, enhances the chimeric protein interaction with membrane lipid surfaces without however destabilizing the overall protein structure. Analysis of interactions between RIPs or RIP based conjugates and lipid surfaces could provide novel insights in the search of more effective selective membrane therapeutics