Automated OMA and Damage Detection: an Opportunity for Smart SHM Systems

Il monitoraggio strutturale si propone di sviluppare sistemi che siano in grado di monitorare un’opera permettendone l’ispezione ed il rilevamento dei danni con il minimo intervento antropico. Esso rappresenta dunque un processo di implementazione di una strategia di identificazione dei danni attraverso la quale, osservando una struttura con una determinata periodicità, è possibile pervenire alla valutazione di alcune caratteristiche del sistema, in modo tale da definirne il suo stato attuale di salute. La sua prima applicazione ha interessato campi differenti da quello dell’ingegneria civile. Infatti, era una tecnica impiegata prevalentemente in ambito meccanico, aeronautico e nell’ingegneria aerospaziale. Successivamente è risultato evidente come fosse una strategia che, se correttamente adattata, poteva essere di grande aiuto per il controllo di tutte le strutture civili presenti sul territorio. Può essere sviluppata come un sistema autonomo integrato su grandi infrastrutture (come ponti, dighe, ecc.) con l’obiettivo di monitorare la risposta della struttura sotto delle sollecitazioni durante la costruzione per modificare i progetti se necessario. Sempre su questo tipo di strutture, può mantenere costante il controllo durante il suo arco di vita per attuare tempestivamente interventi prima che possano crearsi situazioni irreversibili e pericolose. Inoltre, il monitoraggio strutturale può essere impiegato, come verrà mostrato in questa tesi, per il monitoraggio della salute strutturale di edifici storici, appartenenti al patrimonio culturale. Questo patrimonio è diffuso in Europa ed in particolare in Italia. Si parla di edifici anche di notevole entità (come grandi chiese), costruite in epoche molto lontane, la cui conservazione è oggi il focus di molti ricercatori. Il caso studio oggetto del presente lavoro è la torre campanaria di una chiesa nelle Marche, in Italia, le cui tracce storiche risalgono a circa il 1330, con numerosi interventi e rimaneggiamenti successivi fino ad arrivare ai giorni nostri. Con la tecnica del monitoraggio strutturale è possibile valutare il comportamento dinamico della struttura (monitorata) attraverso l’identificazione dei suoi principali parametri modali a partire dall’analisi dei dati acquisiti. Con l’espressione “identificazione dinamica” di una struttura si intendono tutte quelle tecniche, sia analitiche che sperimentali, attraverso le quali è possibile appunto individuare la risposta dinamica della struttura stessa andando ad estrapolare frequenze naturali, corrispondenti forme modali e coefficienti di smorzamento. Soffermandoci su questo concetto, il lavoro è stato inizialmente impostato implementando un processo automatico per l’elaborazione dei dati in uscita dal monitoraggio e quindi per la definizione dei parametri modali della struttura sotto esame depurandoli dagli effetti delle azioni ambientali quali temperatura, velocità media del vento ed umidità. Rimuovere questi fattori esterni dai risultati, permette di ottenere una previsione dell’evoluzione delle caratteristiche modali. Dal loro confronto con il comportamento reale della struttura si possono evidenziare eventuali anomalie. In riferimento a quanto appena detto, risulta oggigiorno di importanza fondamentale riuscire a riconoscere e prevedere il progressivo deterioramento di una struttura. Questo può avvenire per naturale degrado dei materiali, o dopo aver subito vibrazioni impreviste (terremoti, esplosioni, ecc). Focalizzandosi su questo concetto, l’identificazione del danno basata sulla valutazione delle variazioni dei parametri modali, depurati dell’influenza di agenti esterni, può essere un processo lungo. Al contrario, poter conoscere quasi istantaneamente il "nuovo" comportamento della costruzione, è un aspetto da tenere bene in considerazione sia per salvaguardare la vita delle persone, sia per attuare in maniera precisa e puntuale interventi di miglioramento. Essere tempestivi in caso di situazioni critiche, permette di evitare di arrivare a condizioni tali per cui è necessario interrompere l’operatività della struttura per molto tempo pur di poterla recuperare, se possibile. Nel presente lavoro si sono utilizzati metodi basati sull’elaborazione diretta dei dati acquisiti dal sistema di monitoraggio in continuo. In questo modo l’onere computazionale è stato notevolmente ridotto. Non è stato necessario elaborare i dati acquisiti per estrarre le caratteristiche modali del sistema e si è ottenuto un feedback quasi istantaneo di variazioni nel comportamento dinamico. Tali aspetti, risultano significativi quando l’obiettivo è di sviluppare un "monitoraggio sostenibile" sia da un punto di vista economico che di tempistiche.Structural monitoring aims to develop systems that can monitor a structure by allowing its inspection and detection of damage with minimal human intervention. It therefore represents a process of implementing a damage identification strategy through which, by observing a structure with a certain periodicity, it is possible to arrive at an evaluation of specific characteristics of the system, to define its current state of health. Its first application was in fields other than civil engineering. It later became evident that it was a strategy that could be of great help in the control of all civil structures in the area. It can be developed as an autonomous integrated system on big infrastructures with the aim of monitoring the response of the structure under stress during construction to modify designs if necessary. Also, on these types of structures, it can maintain constant control during its life cycle to implement timely interventions. In addition, structural monitoring can be used to monitor the structural health of historical buildings belonging to cultural heritage. We are talking about buildings even of considerable size, built in very distant epochs, the conservation of which is now the focus of many researchers. The case study that is the subject of the present work is the bell tower of a church in the Marche region, Italy, whose historical traces date back to around 1330, with numerous subsequent interventions and remodelling up to the present day. With the technique of structural monitoring, it is possible to assess the dynamic behaviour of the structure through the identification of its main modal. The term 'dynamic identification' of a structure means all those techniques, both analytical and experimental, through which it is possible to identify the dynamic response of the structure itself by extrapolating natural frequencies, corresponding modal shapes and damping coefficients. The work was initially set up by implementing an automatic procedure for processing the output data from the monitoring and thus defining the modal parameters of the structure under examination purifying them from the effects of environmental actions. By removing these external factors from the results, a prediction of the evolution of the modal characteristics can be obtained. Comparing them with the actual behaviour of the structure, any anomalies can be highlighted. Regarding the above, it is nowadays of fundamental importance, to be able to recognise and predict the progressive failure of a structure. This may occur due to natural degradation of materials, or because of unexpected vibrations. Focusing on this concept, the identification of damage based on the evaluation of changes in modal parameters, purified of the influence of external agents, can be a time-consuming process. On the contrary, being able to know almost instantaneously the "new" behaviour of the construction, is an aspect that must be taken into well consideration both for safeguarding people's lives and for the accurate and timely implementation of improvements. In the present work, methods based on the direct processing of data acquired from the continuous monitoring system were used. In this way, the computational burden was reduced. It was not necessary to elaborate the acquired data to extract the modal characteristics of the system, and almost instantaneous feedback of changes in dynamic behaviour was obtained. These aspects are significant when the purpose is to develop "sustainable monitoring" from both an economic and timing perspective

Metabolomic Profiling and Antioxidant Activity of Fruits Representing Diverse Apple and Pear Cultivars

The false fruits of apple (Malus domestica) and pear (Pyrus communis) are consumed all over the world, contributing to the dietary intake of health-promoting antioxidant phytochemicals. For example, polyphenols confer many beneficial effects (according to their chemical structure, bioavailability, and absorption efficiency in the gut) and the consumption of polyphenol-rich apple and pear fruits may therefore reduce the risk of some diseases. However, the content of such molecules is highly dependent on the specific fruit cultivar. To examine this metabolic diversity in detail, we used metabolomic analysis (NMR and HPLC-DAD/MS) to profile the metabolome of six apple and five pear cultivars. We also determined the antioxidant capacity of the extracts (FRAP assay) and correlated this with the metabolomic composition and abundance of specific metabolites. We observed the cultivar-specific accumulation of sugars, amino acids, malic acid, and various polyphenols, which was also related to the growing season for some cultivars. We found that the ancient Italian apple Pom Prussian was enriched for chlorogenic acid as well as more characteristic polyphenols (phloretin derivatives), the pear cultivar Abate Fetel was low in sucrose, and both cultivars displayed high in vitro antioxidant activity. These cultivars may, therefore, be particularly attractive to health-conscious consumers

Degree correlations in signed social networks

We investigate degree correlations in two online social networks where users are connected through different types of links. We find that, while subnetworks in which links have a positive connotation, such as endorsement and trust, are characterized by assortative mixing by degree, networks in which links have a negative connotation, such as disapproval and distrust, are characterized by disassortative patterns. We introduce a class of simple theoretical models to analyze the interplay between network topology and the superimposed structure based on the sign of links. Results uncover the conditions that underpin the emergence of the patterns observed in the data, namely the assortativity of positive subnetworks and the disassortativity of negative ones. We discuss the implications of our study for the analysis of signed complex networks

Cancer burden trends in Umbria region using a joinpoint regression

Introduction. The analysis of the epidemiological data on cancer is an important tool to control and evaluate the outcomes of primary and secondary prevention, the effectiveness of health care and, in general, all cancer control activities. Materials and methods. The aim of the this paper is to analyze the cancer mortality in the Umbria region from 1978 to 2009 and incidence from 1994-2008. Sex and sitespecific trends for standardized rates were analyzed by “joinpoint regression”, using the surveillance epidemiology and end results (SEER) software. Results. Applying the jointpoint analyses by sex and cancer site, to incidence spanning from 1994 to 2008 and mortality from 1978 to 2009 for all sites, both in males and females, a significant joinpoint for mortality was found; moreover the trend shape was similar and the joinpoint years were very close. In males standardized rate significantly increased up to 1989 by 1.23% per year and significantly decreased hereafter by -1.31%; among females the mortality rate increased in average of 0.78% (not significant) per year till 1988 and afterward significantly decreased by -0.92% per year. Incidence rate showed different trends among sexes. In males was practically constant over the period studied (not significant decrease 0.14% per year), in females significantly increased by 1.49% per year up to 2001 and afterward slowly decreased (-0.71% n.s. estimated annual percent change − EAPC). Conclusions. For all sites combined trends for mortality decreased since late ’80s, both in males and females; such behaviour is in line with national and European Union data. This work shows that, even compared to health systems that invest more resources, the Umbria public health system achieved good health outcomes

A tryptophan metabolite prevents depletion of circulating endothelial progenitor cells in systemic low-grade inflammation

BackgroundChronic systemic inflammation reduces the bioavailability of circulating endothelial progenitor cells (EPCs). Indoleamine 2,3-dioxygenase 1 (IDO1), a key enzyme of immune tolerance catalyzing the initial step of tryptophan degradation along the so-called l-kynurenine (l-kyn) pathway, that is induced by inflammatory stimuli and exerts anti-inflammatory effects. A specific relationship between IDO1 activity and circulating EPC numbers has not yet been investigated.MethodsIn this study, circulating EPCs were examined in mice treated with low doses of lipopolysaccharide (LPS) to mimic low-grade inflammation. Moreover, the association between IDO1 activity and circulating EPCs was studied in a cohort of 277 patients with variable systemic low-grade inflammation.ResultsRepeated low doses of LPS caused a decrease in circulating EPCs and l-kyn supplementation, mimicking IDO1 activation, significantly increased EPC numbers under homeostatic conditions preventing EPC decline in low-grade endotoxemia. Accordingly, in patients with variable systemic low-grade inflammation, there was a significant interaction between IDO1 activity and high-sensitivity C-reactive protein (hs-CRP) in predicting circulating EPCs, with high hs-CRP associated with significantly lower EPCs at low IDO1 activity but not at high IDO1 activity.InterpretationOverall, these findings demonstrate that systemic low-grade inflammation reduces circulating EPCs. However, high IDO1 activity and l-kyn supplementation limit circulating EPC loss in low-grade inflammation

Cation Distribution and Vacancies in Nickel Cobaltite

Samples of nickel cobaltite, a mixed oxide occurring in the spinel structure which is currently extensively investigated because of its prospective application as ferromagnetic, electrocatalytic, and cost-effective energy storage material were prepared in the form of nanocrystals stabilized in a highly porous silica aerogel and as unsupported nanoparticles. Nickel cobaltite nanocrystals with average size 4 nm are successfully grown for the first time into the silica aerogel provided that a controlled oxidation of the metal precursor phases is carried out, consisting in a reduction under H2 flow followed by mild oxidation in air. The investigation of the average oxidation state of the cations and of their distribution between the sites within the spinel structure, which is commonly described assuming the Ni cations are only located in the octahedral sites, has been carried out by X-ray Absorption Spectroscopy providing evidence for the first time that the unsupported nickel cobaltite sample has a Ni:Co molar ratio higher than the nominal ratio of 1:2 and a larger than expected average overall oxidation state of the cobalt and nickel cations. This is achieved retaining the spinel structure, which accommodates vacancies to counterbalance the variation in oxidation state

Refinement of the diagnostic approach for the identification of children and adolescents affected by familial hypercholesterolemia: Evidence from the LIPIGEN study

Background and aims: We aimed to describe the limitations of familiar hypercholesterolemia (FH) diagnosis in childhood based on the presence of the typical features of FH, such as physical sings of cholesterol accumulation and personal or family history of premature cardiovascular disease or hypercholesterolemia, comparing their prevalence in the adult and paediatric FH population, and to illustrate how additional information can lead to a more effective diagnosis of FH at a younger age.Methods: From the Italian LIPIGEN cohort, we selected 1188 (>= 18 years) and 708 (<18 years) genetically-confirmed heterozygous FH, with no missing personal FH features. The prevalence of personal and familial FH features was compared between the two groups. For a sub-group of the paediatric cohort (N = 374), data about premature coronary heart disease (CHD) in second-degree family members were also included in the evaluation.Results: The lower prevalence of typical FH features in children/adolescents vs adults was confirmed: the prevalence of tendon xanthoma was 2.1% vs 13.1%, and arcus cornealis was present in 1.6% vs 11.2% of the cohorts, respectively. No children presented clinical history of premature CHD or cerebral/peripheral vascular disease compared to 8.8% and 5.6% of adults, respectively. The prevalence of premature CHD in first-degree relatives was significantly higher in adults compared to children/adolescents (38.9% vs 19.7%). In the sub-cohort analysis, a premature CHD event in parents was reported in 63 out of 374 subjects (16.8%), but the percentage increased to 54.0% extending the evaluation also to second-degree relatives.Conclusions: In children, the typical FH features are clearly less informative than in adults. A more thorough data collection, adding information about second-degree relatives, could improve the diagnosis of FH at younger age

Lipoprotein(a) Genotype Influences the Clinical Diagnosis of Familial Hypercholesterolemia

: Background Evidence suggests that LPA risk genotypes are a possible contributor to the clinical diagnosis of familial hypercholesterolemia (FH). This study aimed at determining the prevalence of LPA risk variants in adult individuals with FH enrolled in the Italian LIPIGEN (Lipid Transport Disorders Italian Genetic Network) study, with (FH/M+) or without (FH/M-) a causative genetic variant. Methods and Results An lp(a) [lipoprotein(a)] genetic score was calculated by summing the number risk-increasing alleles inherited at rs3798220 and rs10455872 variants. Overall, in the 4.6% of 1695 patients with clinically diagnosed FH, the phenotype was not explained by a monogenic or polygenic cause but by genotype associated with high lp(a) levels. Among 765 subjects with FH/M- and 930 subjects with FH/M+, 133 (17.4%) and 95 (10.2%) were characterized by 1 copy of either rs10455872 or rs3798220 or 2 copies of either rs10455872 or rs3798220 (lp(a) score ≥1). Subjects with FH/M- also had lower mean levels of pretreatment low-density lipoprotein cholesterol than individuals with FH/M+ (t test for difference in means between FH/M- and FH/M+ groups <0.0001); however, subjects with FH/M- and lp(a) score ≥1 had higher mean (SD) pretreatment low-density lipoprotein cholesterol levels (223.47 [50.40] mg/dL) compared with subjects with FH/M- and lp(a) score=0 (219.38 [54.54] mg/dL for), although not statistically significant. The adjustment of low-density lipoprotein cholesterol levels based on lp(a) concentration reduced from 68% to 42% the proportion of subjects with low-density lipoprotein cholesterol level ≥190 mg/dL (or from 68% to 50%, considering a more conservative formula). Conclusions Our study supports the importance of measuring lp(a) to perform the diagnosis of FH appropriately and to exclude that the observed phenotype is driven by elevated levels of lp(a) before performing the genetic test for FH

The “Diabetes Comorbidome”: A Different Way for Health Professionals to Approach the Comorbidity Burden of Diabetes

(1) Background: The disease burden related to diabetes is increasing greatly, particularly in older subjects. A more comprehensive approach towards the assessment and management of diabetes’ comorbidities is necessary. The aim of this study was to implement our previous data identifying and representing the prevalence of the comorbidities, their association with mortality, and the strength of their relationship in hospitalized elderly patients with diabetes, developing, at the same time, a new graphic representation model of the comorbidome called “Diabetes Comorbidome”. (2) Methods: Data were collected from the RePoSi register. Comorbidities, socio-demographic data, severity and comorbidity indexes (Cumulative Illness rating Scale CIRS-SI and CIRS-CI), and functional status (Barthel Index), were recorded. Mortality rates were assessed in hospital and 3 and 12 months after discharge. (3) Results: Of the 4714 hospitalized elderly patients, 1378 had diabetes. The comorbidities distribution showed that arterial hypertension (57.1%), ischemic heart disease (31.4%), chronic renal failure (28.8%), atrial fibrillation (25.6%), and COPD (22.7%), were the more frequent in subjects with diabetes. The graphic comorbidome showed that the strongest predictors of death at in hospital and at the 3-month follow-up were dementia and cancer. At the 1-year follow-up, cancer was the first comorbidity independently associated with mortality. (4) Conclusions: The “Diabetes Comorbidome” represents the perfect instrument for determining the prevalence of comorbidities and the strength of their relationship with risk of death, as well as the need for an effective treatment for improving clinical outcomes