2,130 research outputs found

    One-year dynamic monitoring of a historic tower: damage detection under changing environment

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    The paper summarizes the conceptual development of a vibration-based strategy suitable to the structural health monitoring of ancient masonry towers and exemplifies its application in the continuous dynamic monitoring of the tallest historic tower in Mantua, Italy. The presented approach is based on the installation of low-cost monitoring systems (consisting of few accelerometers and temperature sensors) and on the combined use of automated operational modal analysis, regression models to mitigate the environmental effects on identified natural frequencies and multivariate statistical tools to detect the occurrence of abnormal structural changes. The application of the adopted strategy to 15 months of continuously collected experimental data: (1) highlighted the effect of temperature on the automatically identified natural frequencies; (2) demonstrated the practical feasibility of damage detection methods based on natural frequency shifts; (3) provided a clear evidence of the possible key role of continuous dynamic monitoring in the preventive conservation of historic towers

    One-year dynamic monitoring of a masonry tower

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    The paper presents some results of the continuous dynamic monitoring program carried out on the tallest historic tower in Mantua, Italy. This project follows an extensive diagnostic investigation aimed at assessing the structural condition of the tower after the Italian earthquakes of May 2012. A simple dynamic monitoring system was permanently installed in the upper part of the building and automatic modal identification was performed. The results allow to evaluate the effects of changing temperature on automatically identified natural frequencies, to verify the practical feasibility of damage detection methods based on natural frequencies shifts and provide clear evidence of the possible key role of continuous dynamic monitoring in the preventive conservation of historic towers

    Dynamic and seismic health monitoring of a historic masonry tower

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    The paper presents some results of the continuous dynamic/seismic monitoring program carried out on the tallest historic tower in Mantua, Italy. This project follows an extensive diagnostic investigation aimed at assessing the structural condition of the tower after the Italian earthquakes of May 2012. A simple dynamic monitoring system was installed in the tower to evaluate the dynamic response especially to the expected sequence of far-field earthquakes and to check the possible evolution of the natural frequencies; the response to ambient excitation has been continuously collected in 1-hour records since late December 2012. The paper summarizes the results of the continuous dynamic monitoring for a period of 8 months, highlighting the effect of temperature on automatically identified natural frequencies, the dynamic response to few seismic events and the key role of permanent dynamic monitoring in the diagnosis of the investigated historic building

    Stand-alone wearable system for ubiquitous real-time monitoring of muscle activation potentials

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    Wearable technology is attracting most attention in healthcare for the acquisition of physiological signals. We propose a stand-alone wearable surface ElectroMyoGraphy (sEMG) system for monitoring the muscle activity in real time. With respect to other wearable sEMG devices, the proposed system includes circuits for detecting the muscle activation potentials and it embeds the complete real-time data processing, without using any external device. The system is optimized with respect to power consumption, with a measured battery life that allows for monitoring the activity during the day. Thanks to its compactness and energy autonomy, it can be used outdoor and it provides a pathway to valuable diagnostic data sets for patients during their own day-life. Our system has performances that are comparable to state-of-art wired equipment in the detection of muscle contractions with the advantage of being wearable, compact, and ubiquitous

    Manfredo Tafuri. Studi, incontri, opere 1935-1994

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    Il documento presenta una geografia del pensiero, degli scritti, degli studi e delle figure che più hanno caratterizzato la vita e la ricerca di Manfredo Tafuri. Il periodo scelto è quello di tutto l'arco della sua vita, dalla nascita nel 1935 alla sua prematura scomparsa nel 1994

    Palmprint principal lines extraction

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    The palmprint recognition has become a focus in biological recognition and image processing fields. In this process, the features extraction (with particular attention to palmprint principal line extraction) is especially important. Although a lot of work has been reported, the representation of palmprint is still an open issue. In this paper we propose a simple, efficient, and accurate palmprint principal lines extraction method. Our approach consists of six simple steps: normalization, median filtering, average filters along four prefixed directions, grayscale bottom-hat filtering, combination of bottom-hat filtering, binarization and post processing. The contribution of our work is a new method for palmprint principal lines detection and a new dataset of hand labeled principal lines images (that we use as ground truth in the experiments). Preliminary experimental results showed good performance in terms of accuracy with respect to three methods of the state of the art

    First data on microflora of loggerhead sea turtle (Caretta caretta) nests from the coastlines of Sicily

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    Caretta caretta is threatened by many dangers in the Mediterranean basin, but most are human-related. The purposes of this research were: (i) to investigate microflora in samples from six loggerhead sea turtle nests located on the Sicilian coast and (ii) to understand microbial diversity associated with nests, with particular attention to bacteria and fungi involved in failed hatchings. During the 2016 and 2018 summers, 456 eggs and seven dead hatchling from six nests were collected. We performed bacteriological and mycological analyses on 88 egg samples and seven dead hatchlings, allowing us to isolate: Fusarium spp. (80.6%), Aeromonas hydrophila (55.6%), Aspergillus spp. (27.2%) and Citrobacter freundii (9%). Two Fusarium species were identified by microscopy and were confirmed by PCR and internal transcribed spacer sequencing. Statistical analyses showed significant differences between nests and the presence/absence of microflora, whereas no significant differences were observed between eggs and nests. This is the first report that catalogues microflora from C. caretta nests/eggs in the Mediterranean Sea and provides key information on potential pathogens that may affect hatching success. Moreover, our results suggest the need for wider investigations over extensive areas to identify other microflora, and to better understand hatching failures and mortality related to microbial contamination in this important turtle species

    Arachnomelia in Brown Swiss cattle maps to chromosome 5

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    Arachnomelia in Brown Swiss cattle is a monogenic autosomal recessive inherited congenital disorder of the skeletal system giving affected calves a spidery look (OMIA ID 000059). Over a period of 20years 15 cases were sampled in the Swiss and Italian Brown cattle population. Pedigree data revealed that all affected individuals trace back to a single acknowledged carrier founder sire. A genome scan using 240 microsatellites spanning the 29 bovine autosomes showed homozygosity at three adjacent microsatellite markers on bovine Chr 5 in all cases. Linkage analysis confirmed the localization of the arachnomelia mutation in the region of the marker ETH10. Fine-mapping and haplotype analysis using a total of 34 markers in this region refined the critical region of the arachnomelia locus to a 7.19-Mb interval on bovine Chr 5. The disease-associated IBD haplotype was shared by 36 proven carrier animals and allows marker-assisted selection. As the corresponding human and mouse chromosome segments do not contain any clear functional candidate genes for this disorder, the mutation causing arachnomelia in the Brown Swiss cattle might help to identify an unknown gene in bone developmen

    Trans-epithelial transport of the betalain pigments indicaxanthin and betanin across Caco-2 cell monolayers and influence of food matrix

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    Purpose: This study investigated the absorption mechanism of the phytochemicals indicaxanthin and betanin and the influence of their food matrix (cactus pear and red beet) on the intestinal transport. Methods: Trans-epithelial transport of dietary-consistent amounts of indicaxanthin and betanin in Caco-2 cell monolayers seeded on TranswellR inserts was measured in apical to basolateral (AP-BL) and basolateral to apical (BL-AP) direction, under an inwardly directed pH gradient (pH 6.0/7.4, AP/BL) mimicking luminal and serosal sides of human intestinal epithelium. The effect of inhibitors of membrane transporters on the absorption was also evaluated. Contribution of the paracellular route was investigated after EDTA treatment of the cell monolayer. In vitro digestion of betalainic food was performed to provide a post-intestinal fraction containing bioaccessible pigments. Results: Apparent permeability coefficients (P app) in the absorptive direction were (4.4 ± 0.4) × 10-6 and (3.2 ± 0.3) × 10-6 cm s-1 for indicaxanthin and betanin, respectively. Transport of indicaxanthin was non-polarized, linear as a function of time and concentration, and unaffected by inhibitors of membrane transporters. Betanin exhibited significantly different bidirectional P app values and non-linear efflux kinetics. The concentration- dependent betanin efflux was described by a kinetic model including one non-saturable (K d = 0.042 μL cm-2 min-1) and one saturable component identified as the apical multidrug resistance-associated protein 2 (MRP2; K m = 275 μM; J max = 42 pmol min-1 cm-2). Permeation of both betalains increased remarkably after EDTA treatment of the cell monolayer. Neither indicaxanthin nor betanin underwent metabolic transformation. Food matrix did not affect trans-epithelial transfer of indicaxanthin, but reduced the absorption rate of betanin, red beet more than cactus pear. Conclusions: Dietary indicaxanthin and betanin can substantially be absorbed through paracellular junctions of intestinal epithelial cells. Additional trans-membrane permeation can be considered for betanin, whose absorption is limited by a MRP2-mediated efflux and negatively affected by its food matrix. Present findings are consistent with the quite higher bioavailability of indicaxanthin over betanin established in humans. © 2012 Springer-Verlag
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