986 research outputs found
Multimedia digital solutions from image and range based models for ancient landscapes communication
The paper presents the results of an interdisciplinary project which aimed at the dissemination of some archaeological remains producing multimedia contents from multisensor surveyed 3D data. The scope of this application pertained to the use of 3D detailed models as a base for some video-installations with the aim to arouse the visitors’ emotions and improve their museum experience. This work has been applied to the Arch of Augustus located in the archaeological site of Susa and to two ancient Roman marble statues, found in the city of Susa in 1802 and now displayed in the Archaeological Museum of Turin. The Arch of Augustus is in a remarkable state of conservation. Its decorated frieze tells about the peace between the Romans and the Celts but it is difficult to see for visitors at the ground level. A multisensor 3D survey, by means of laser scanning technique and photogrammetric method, made it possible to process a detailed 3D textured model, which provided the base for the creation of a life-size model to be placed in the Museum of Susa on which a designed didactic video map is projected, which explains the meaning of the frieze. The two statues, known as ‘busti loricati di Susa’ and representing two Roman emperors, were surveyed with a photogrammetric method with the aim of processing two 3D models representing the statues before the 19th century restoration, on the basis of archival sources. These models provided the base for a video installation for the museum which simulates a holographic projection and explains the different armour parts highlighting them in sequence. Nowadays modern metric survey technologies allow us to collect and process very detailed 3D models able to satisfy a wide variety of applications field, from specialized representation to didactic final uses in museums exhibitions
Freezing of a Lennard-Jones fluid: from nucleation to spinodal regine
Using molecular dynamics, we investigate the crystal nucleation in a Lennard-Jones fluid as a function of the degree of supercooling. At moderate supercooling, a nucleation picture applies, while for deeper quenches, the phenomenon progressively acquires a spinodal character. We show that in the nucleation regime, the freezing is a two-step process. The formation of the critical nucleus is indeed preceded by the abrupt formation of a precritical crystallite from a density fluctuation in the fluid. In contrast, as the degree of supercooling is increased, crystallization proceeds in a more continuous and collective fashion and becomes more spatially diffuse, indicating that the liquid is unstable and crystallizes by a spinodal mechanism
High-resolution lightning detection and possible relationship with rainfall events over the Central Mediterranean area
Lightning activity is usually associated with precipitations events and represents a possible indicator of climate change, even contributing to its increase with the production of NOx gases. The study of lightning activity on long temporal periods is crucial for fields related to atmospheric phenomena from intense rain-related hazard processes to long-term climate changes. This study focuses on 19 years of lightning-activity data, recorded from Italian Lightning Detection Network SIRF, part of the European network EUCLID (European Cooperation for Lightning Detection). Preliminary analysis was dedicated to the spatial and temporal assessment of lightning through detection in the Central Mediterranean area, focusing on yearly and monthly data. Temporal and spatial features have been analyzed, measuring clustering through the application of global Moran’s I statistics and spatial local autocorrelation; a Mann–Kendall trend test was performed on monthly series aggregating the original data on a 5 × 5 km cell. A local statistically significant trend emerged from the analysis, suggesting a possible linkage between surface warming and lightning activity
Photoelasticity of sodium silicate glass from first principles
Based on density-functional perturbation theory we have computed the
photoelastic tensor of a model of sodium silicate glass of composition
(NaO)(SiO) (NS3). The model (containig 84 atoms) is
obtained by quenching from the melt in combined classical and Car-Parrinello
molecular dynamics simulations. The calculated photoelastic coefficients are in
good agreement with experimental data. In particular, the calculation
reproduces quantitatively the decrease of the photoelastic response induced by
the insertion of Na, as measured experimentally.
The extension to NS3 of a phenomenological model developed in a previous work
for pure a-SiO indicates that the modulation upon strain of other
structural parameters besides the SiOSi angles must be invoked to explain the
change in the photoelstic response induced by Na
SfM for Orthophoto to Generation: A Winning Approach for Cultural Heritage Knowledge
3D detailed models derived from digital survey techniques have increasingly developed and focused in many field of application.
The high detailed content and accuracy of such models make them so attractive and usable for large sets of purposes in Cultural
Heritage. The present paper focuses on one of the main techniques used nowadays for Cultural Heritage survey and documentation:
the image matching approach or Structure from Motion (SfM) technique. According to the low cost nature and the rich content of
derivable information, these techniques are extremely strategic in poor available resources sectors such as Cultural Heritage
documentation.
After an overview of the employed algorithms and used approaches of SfM computer vision based techniques, the paper is focused in
a critical analysis of the strategy used by two common employed software: the commercial suite Agisoft Photoscan and the open
source tool MicMac realized by IGN France. The experimental section is focused on the description of applied tests (from RPAS
data to terrestrial acquisitions), purposed to compare different solutions in various featured study cases. Finally, the accuracy
assessment of the achieved products is compared and analyzed according to the strategy employed by the studied software
Case report: De novo mutation of a-galactosidase A in a female patient with end-stage renal disease: report of a case of late diagnosis of Anderson–Fabry disease
Background: Anderson-Fabry disease (AFD) is an X-linked disease that results from reduced activity of the enzyme galactosidase alpha (GLA). When the GLA gene sequence is altered by mutations that alter the normal DNA sequence, variants of the alpha-galactosidase A enzyme are produced, which may or may not function. These mutations are responsible for Fabry disease, and to date, over 800 different mutations of the gene have been described in patients with Anderson-Fabry disease. In this case, we report the case of a woman who is the sole family member with this type of mutation.Case presentation: We report a case of a 52-year-old woman with end-stage chronic kidney disease in dialysis treatment. The patient's alpha-galactosidase activity was 6.6 nmol/ml/h in whole blood, and lyso-GB3 levels were 11.45 nmol/L (normal range < 2.3 nmol/L). Alpha-galactosidase A gene sequence analysis revealed a pathogenic variant of c.947dupT in exon 6, leading to the p. I317NfsTer16 amino acid substitution. The genetic analysis did not detect the same mutation in any of the other screened family members.Conclusion: The international Fabry disease genotype-phenotype database (dbFGP) reports a pathogenic variant c.947dupT in exon 6 that is probably associated with a classical phenotype of Fabry disease. In this case report, we report the case of a woman who is the sole family member with this type of pathogenic variant. Similar situations have not been described in the literature for this pathogenic variant, and it represents an important case of inter- and intrafamilial variability in patients with Fabry disease. The literature shows that de novo pathogenic variants are frequently found in the context of Fabry disease
Thermal conductivity of one-dimensional lattices with self-consistent heat baths: a heuristic derivation
We derive the thermal conductivities of one-dimensional harmonic and
anharmonic lattices with self-consistent heat baths (BRV lattice) from the
Single-Mode Relaxation Time (SMRT) approximation. For harmonic lattice, we
obtain the same result as previous works. However, our approach is heuristic
and reveals phonon picture explicitly within the heat transport process. The
results for harmonic and anharmonic lattices are compared with numerical
calculations from Green-Kubo formula. The consistency between derivation and
simulation strongly supports that effective (renormalized) phonons are energy
carriers in anharmonic lattices although there exist some other excitations
such as solitons and breathers.Comment: 4 pages, 3 figures. accepted for publication in JPS
Salivary psoriasin (S100A7) correlates with diffusion capacity of carbon monoxide in a large cohort of systemic sclerosis patients
Background: Systemic sclerosis (SSc) is an autoimmune disease characterized by progressive fibrosis of the skin and the internal organs. In a previous work we suggested a correlation between levels of salivary psoriasin (S100A7) and pulmonary involvement in SSc patients. The goals of this study are to determine the distribution characteristics of psoriasin in whole saliva (WS) of SSc and healthy donor populations and define its predictive value on diffusion capacity of carbon monoxide (DLCO), along with others clinical parameters. Methods: Salivary level of psoriasin was determined by ELISA kit in 134 SSc patients, 63 Raynaud syndrome patients, 40 patients affected by other connective diseases (non-case) and 74 healthy control subjects. Results: A significant increase of salivary psoriasin was observed in SSc patients when compared with other healthy and pathological controls. Moreover, we confirmed the efficacy of salivary psoriasin to correlate with DLCO in a large cohort of SSc patients. Conclusions: Overall our results suggest a rapid, non invasive and low costing method which can help clinicians in the evaluation of SSc pulmonary involvement
A comparative blind study between skin biopsy and seed amplification assay to disclose pathological α-synuclein in RBD
To compare the diagnostic accuracy of the immunofluorescence (IF) technique and aSyn-seed amplification assay (aSyn-SAA) of skin and cerebrospinal fluid (CSF) in disclosing pathological α-syn in idiopathic idiopathic REM sleep behavior disorder (iRBD) as early phase of a synucleinopathy. We prospectively recruited 41 patients with iRBD and 40 matched clinical controls including RBD associated with type 1 Narcolepsy (RBD-NT1, 21 patients), iatrogenic causes (2 pt) or OSAS (6 pt) and 11 patients with peripheral neuropathies. IF from samples taken by skin biopsy and aSyn-SAA from skin and CSF samples were analysed blinded to the clinical diagnosis. IF showed a good diagnostic accuracy (89%) that was lower in the case of skin and CSF-based aSyn-SAA (70% and 69%, respectively) because of a lower sensitivity and specificity. However, IF showed a significant agreement with CSF aSyn-SAA. In conclusion, our data may favor the use of skin biopsy and aSyn-SAA as diagnostic tools for a synucleinopathy in iRBD
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