Colorimetry applied to the field of cultural heritage: examples of study cases

For a few years now, the Dipartimento di Storie e Metodi per la Conservazione dei Beni Culturali of the Alma Mater Studiorum Università di Bologna (sede di Ravenna) has been creating a Diagnostic Laboratory for the study on the “system: cultural heritage/conservation environment”. In the present paper the results of different surveys concerning the use of colorimetry on different typologies of art works are reported: graphic documents (fig. 1); oil painting on board and canvas (fig. 2); wall painting (fig. 3); stony materials consolidated with ethyl silicate (fig. 4). Measurements of the chromatic parameters, according to the CIE L*a*b* chromaticity diagram and to the UNI 8941 Standard Coloured surfaces, were carried out with the spectrophotometric colorimeter Minolta CM-2600D model. The reference measurements (targets) were carried out on every typology of works. Such targets, recorded on the tool or in the computer, could be considered in order to draw a comparison in time on the same studied surface. It is then possible to check the trend of the chromatic alteration as an effect of interaction of the environment of location-conservation with the art work and, then to determine the causes, i.e the environmental operating-factors. The measurements of the chromatic parameters for graphic documents and for wall paintings have also allowed us to establish if the modifications, caused by an inappropriate environment, must be linked to irreversible or reversible effects and, then, with the possibility of being removed. As regards wall paintings, the respect of the “noble patina” was showed, as established by the Card of Restoration, by means of the measurement of the + b* parameters (yellow degree). The studies on stony materials aimed at the evaluation of the chromatic alterations of the art works previously consolidated with various products based on ethyl silicates: different results were reached according to the different degree of stone cohesion, anisotropy of the material and different exposure conditions of the works. Such researches may contribute to applying colorimetry in the field of cultural heritage

Towards the de\ufb01nition of a new river water line for North-Eastern Italy

In the last decades there has been active research on the relation between the stable isotopic composition of precipitation and climate variations at the regional scale. Particularly, the analysis of meteoric water lines is an important tool to understand climate processes at the local/regional scale. In this view, considering the strict relation between the isotopic composition of river water and the one of precipitation, surface running waters (i.e. rivers, streams, creeks) and their catchments can be considered as \u201cnatural pluviometers\u201d. In this study the analysis of the isotopic composition of surface waters was carried out in order to develop a new meteoric water line of North-East Italy. The dataset includes samples collected between 2012 and 2016 from i) small catchments, typically < 30 Km2 (Ressi Creek, Bridge Creek and Vauz Creek, Noce Bianco stream, Posina river), where it is easier to relate the stream water isotopic composition to distinct meteoric end-members (e.g., rainfall,snowmeltandglaciermelt);andii)largebasins(Adige:12,100Km2 andPo:71,000Km2)whichintegrate multiple components giving information at the regional scale. Preliminary results show that distinct river water lines are characterized by different slopes and intercepts. The slopes vary between 5.46 and 8.02, whereas the intercepts vary between -9.15 and 11.82. In particular river meteoricwaterlinesde\ufb01nedforRessiCreek(\u3b4Dh\uaf7.48 \u3b418O+10.27,n=831;R2 =0.88)andNoceBiancostream (\u3b4Dh\uaf7.66 \u3b418O+7.27, n=484; R2 = 0.95) con\ufb01rm the similarity with the meteoric line developed for northern Italy. On the contrary, the isotopic composition of streams in small (< 10 Km2) snow-dominated catchments (Bridge Creek and Vauz Creek) deviate from the North Italy meteoric line due to the important contribution of snowmelt that is typically characterized by a different isotopic signature compared to the precipitation input. River water lines for large basins (Po and Adige) are characterized by slopes and intercepts in the range of the Global Meteoric Water Line. Finally, it is important to emphasize that the current dataset, progressively updated, represents a snapshot of a short monitoring period and that future investigations are useful to highlight seasonal variations and on-going environmental changes

Balancing protection and investment: structural reforms in five countries

Structural Reforms (SRs) are increasingly at the core of the European and national agenda. But what are SRs? And what are the main factors shaping their content? This analysis of the structural reforms adopted, between 2008 and 2015 in five European Union (EU) countries - the Czech Republic, Finland, Germany, Ireland and Italy - allows us to address these two questions. The book proposes a new definition of SRs, combining supply-side and more demand-side policy measures. An analysis of the five countries under scrutiny shows how a combination of EU constraints and opportunities, domestic path-dependency and political dynamics has resulted in different structural reform trends: while some countries have experienced an overall devaluation in social standards (e.g. Ireland), others have pursued more mixed strategies. What is more, SRs have gone through different periods. After a first phase of anti-cyclical measures, austerity dominated between 2011 and 2013. In more recent years, many countries have followed a more pro-growth strategy. The book provides evidence that the EU influenced SRs but lacked a coherent agenda to support growth. In such a context, different countries implemented different reform strategies, reflecting their (partly) diverging socio-economic models

Diagnostic investigations and historical-stylistic evaluation on the oil painting: "reading man by oil lamp light"

This investigation intends to verify the attribution of the oil painting (70x50,5 cm) portraying a reading man by oil lamp light, to Gerrit van Hontorst. The note refers not only to a stylistic and historical-artistical evaluation but also to the knowledge, through diagnostic techniques, of the application to characterize components of matter, and of the manufacture execution technique and preservation conditions. This investigation denies the attribution to the painter Gerrit van Hontorst, but it does not exclude a dating within the XVII century

Diagnosis and digitization of Dantesque Code “Phillipps 9589”

This work concerns the study of Dante’s Code, illuminated on parchment, which is preserved at the Library of “Centro Dantesco dei Frati Minori Conventuali” in Ravenna. This Code is well-known by the international scientific Community as Phillipps 9589 and its notoriety is not only due to the fact that it’s the only Dante’s Palimpsest, but also because it preserves, at the scripto superior, one of the older witness of that branch of handwritten tradition of Dante’s Commedia named “Tradition a”, the so-called “old Vulgate”. The research, worked out for several stages, had aimed to examine the technical-diagnostic aspects, in particular the general purposes had been: – evaluation about the state of preservation; – materials characterization; – improvement of the legibility of Dante’s text and Palimpsest reading; – evaluation about the preservative environment; – code digitization suitable for a intranet and internet use. In this connection, the following non-destructive diagnostic techniques bad been employed, also related to a documentary aim: – image analysis videomicroscope; – spectrophotometric colorimetry; – X-ray fluorescence (XRF); – Multispectral Imaging System (MuSIS); – environmental monitoring Instruments (thermohygrometer, illuminometer, aerosol spectrometer PTS e PM10)

Diagnostic and historical-iconographic study on frescos in Palazzo Maioli (Ravenna)

The pictures discovered in Ravenna at Maioli Palace (Ravenna) have been subjected to an analytical survey, both during and after the works of a restoration performed at the Restoration Laboratory. This building, set during the time of the Venetian rule in the town of Romagna (1447-1509), belonged for centuries to the noble Maioli Family, that had come from Faenza. The walls, taken into consideration, show four "pictured levels", i.e. four different times about when the four pictures have been performed. The first one refers to the construction period of the building, the second one is the one studied, the third one can be connected to the Seventeenth century, according to the stylistic details of the Pompeian period. While the forth one is dated back to the end of the Eighteenth century, since the decorative part is typical of that time (with "decorative part" we refer to the "stencil" decorations, i.e. applications of pictures, inks or colours by means of special little masks). The experimental study carried out on two kinds of pictured samples (chosen according to their kind of pigments i.e.: yellow and black) as focused on: the colorimetry, in order to determine the components of the chromaticity; the fluorescence spectrometry to X ray, to characterize the pigments used; the thermal analysis with the goal of finding out the kind of plaster; the video-microscopy to get documentary and cognitive purposes. A systematic analysis of the pictures was justified both by the will of finding the pictorial technique of the painter, and by the wish to be able to date them back to the period of their creation, since at the moment, there is no documentation about these issues

Diagnostic investigation and historical-stylistic evaluation of oil painting on metal board. Example of “Christ Crucified with two mourning angels”

The oil painting on metal board (40 x 30 cm) under study was bought from the antiquarian French market and bears a very common representation that derives from one of Michelangelo’s designs: “Cristo Crocifisso con due angeli dolenti”. The present paper not only refers to a stylistic and historical-artistic assessment, but also alludes to knowledge in a general sense through diagnostic technique and preservation conditions. The results of the diagnostic study, together with the stylistic analysis, have confirmed that the painting is an ancient one that dates back to the first decades of the XVIIth century

The Impact of Gender and Personality in Human-AI Teaming: The Case of Collaborative Question Answering

This paper discusses the results of an exploratory study aimed at investigating the impact of conversational agents (CAs) and specifically their agential characteristics on collaborative decision-making processes. The study involved 29 participants divided into 8 small teams engaged in a question-and-answer trivia-style game with the support of a text-based CA, characterized by two independent binary variables: personality (gentle and cooperative vs blunt and uncooperative) and gender (female vs male). A semi-structured group interview was conducted at the end of the experimental sessions to investigate the perceived utility and level of satisfaction with the CAs. Our results show that when users interact with a gentle and cooperative CA, their user satisfaction is higher. Furthermore, female CAs are perceived as more useful and satisfying to interact with than male CAs. We show that group performance improves through interaction with the CAs, confirming that a stereotype favoring the female with a gentle and cooperative personality combination exists in regard to perceived satisfaction, even though this does not lead to greater perceived utility. Our study extends the current debate about the possible correlation between CA characteristics and human acceptance and suggests future research to investigate the role of gender bias and related biases in human-AI teaming

Painting the black box white: experimental findings from applying XAI to an ECG reading setting

The shift from symbolic AI systems to black-box, sub-symbolic, and statistical ones has motivated a rapid increase in the interest toward explainable AI (XAI), i.e. approaches to make black-box AI systems explainable to human decision makers with the aim of making these systems more acceptable and more usable tools and supports. However, we make the point that, rather than always making black boxes transparent, these approaches are at risk of \emph{painting the black boxes white}, thus failing to provide a level of transparency that would increase the system's usability and comprehensibility; or, even, at risk of generating new errors, in what we termed the \emph{white-box paradox}. To address these usability-related issues, in this work we focus on the cognitive dimension of users' perception of explanations and XAI systems. To this aim, we designed and conducted a questionnaire-based experiment by which we involved 44 cardiology residents and specialists in an AI-supported ECG reading task. In doing so, we investigated different research questions concerning the relationship between users' characteristics (e.g. expertise) and their perception of AI and XAI systems, including their trust, the perceived explanations' quality and their tendency to defer the decision process to automation (i.e. technology dominance), as well as the mutual relationships among these different dimensions. Our findings provide a contribution to the evaluation of AI-based support systems from a Human-AI interaction-oriented perspective and lay the ground for further investigation of XAI and its effects on decision making and user experience.Comment: 15 pages, 7 figure

TUMOR NECROSIS FACTOR ALPHA TRIGGERS OSTEOGENESIS THROUGH THE INVOVLVEMENT OF Gs-COUPLED RECEPTOR SIGNALS

Tumor Necrosis Factor alpha (TNF-α) plays a role in several chronic immune and inflammatory diseases, where inhibition of TNF has led to significant clinical improvement. Actually, this cytokine is involved in bone healing by affecting mesenchymal stem cell (MSC) behaviour in a dose- and time-dependent manner1,2. Indeed, in the early inflammatory phase after fracture, low doses of TNF-α are required to favour MSC migration, survival and differentiation, thus initiating bone repair. At high dose, in the chronic uncontrolled phase of inflammation, the same cytokine has destructive effects on bone and contribute to bone loss1,2. As other soluble factors released in cell microenvironment, the cytokine modulates expression and functioning of different G protein coupled receptors (GPCRs) and of their regulatory proteins (GPCR regulated kinases, GRKs)3, thus dictating the final biological outcome of these receptor proteins in controlling bone anabolic processes. Herein, we investigated the effects of TNF-α low doses on the expression and functional responsiveness of A2B adenosine receptor (A2B AR), a Gs-coupled puringergic receptor that controls mesenchymal stem cell (MSC) differentiation to osteoblasts4,5. In our hands, TNF-α exerted a pro-differentiating action on MSCs, pushing towards an osteoblast phenotype, and without any effects on cell proliferation. The cytokine increased the A2B AR-mediated pro-osteogenic effects, through the A2B AR desensitization impairment mediated by GRK2 inhibition. These data i) support the anabolic effect of sub-massimal concentration of TNF-α in bone reparative processes and ii) demonstrate that the cytokine regulates GPCR responses by interfering with desensitization machinery and potentiating in turn the anabolic responses evoked by Gs-GPCRs. Overall these results indicated that manipulating MSC local environment by lregulates membrane receptors favouring bone remodelling