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This special issue on three-dimensional (3D) sound reconstruction for virtual auditory displays: applications in buildings contains six research papers. Among them, three articles describe virtual reconstruction of important theatres and opera houses. The remaining articles focus on theoretical approaches of virtual sound localization or auralization., (© 2023 Acoustical Society of America.)

Throughout history, many buildings of significant cultural value have been lost due to natural disasters (e.g., earthquakes, volcanic eruptions, subsidence, etc.) as well as other human causes (e.g., fire, war destruction, etc.). The Tajo Opera theatre was hit by an earthquake that led to the collapse of the entire structure eight months after it was built. This paper deals with the revival of the acoustic characteristics of one of the masterpieces of the architect Giovanni Carlo Sicinio Galli Bibiena. The realization of a three-dimensional (3D) model that faithfully reproduces the architectural features of the Royal Tajo Opera theatre of Lisbon allows the authors to perform acoustic simulations that reveal the sound field representing the environment perceived by the audience during artistic performances in Lisbon in 1755. In addition, the simulated results have been compared with the values of the Teatro Comunale of Bologna, which has a similar bell-shaped plan layout and has already been studied by the authors. For the comparison of the two opera theatres, both the stalls and the balconies have been considered.

Anti-double-stranded DNA antibodies (anti-dsDNA) are considered a specific marker for systemic lupus erythematosus (SLE). Though the Farr technique was once the reference method for their detection, it has been almost entirely replaced by more recently developed assays. However, there is still no solid evidence of the commutability of these methods in terms of diagnostic accuracy and their correlation with the Crithidia luciliae immunofluorescence test (CLIFT). Anti-dsDNA antibody levels were measured in 80 subjects: 24 patients with SLE, 36 disease controls drawn from different autoimmune rheumatic diseases (14 systemic sclerosis, 10 Sjögren's syndrome, nine autoimmune myositis, three mixed connective tissue disease), 10 inflammatory arthritis and 10 apparently healthy blood donors by eight different methods: fluorescence enzyme immunoassay, microdot array, chemiluminescent immunoassay (two assays), multiplex flow immunoassay, particle multi-analyte technology immunoassay and two CLIFT. At the recommended manufacturer cut-off, the sensitivity varied from 67% to 92%, while the specificity ranged from 84% to 98%. Positive agreement among CLIFT and the other assays was higher than negative agreement. Mean agreement among methods assessed by the Cohen's kappa was 0.715, ranging from moderate (0.588) to almost perfect (0.888). Evaluation of the concordance among quantitative values by regression analysis showed a poor correlation index (mean r2, 0.66). The present study shows that current technologies for anti-dsDNA antibody detection are not fully comparable. In particular, their different correlation with CLIFT influences their positioning in the diagnostic algorithm for SLE (either in association or sequentially). Considering the high intermethod variability, harmonization and commutability of anti-dsDNA antibody testing remains an unachieved goal., (© 2022 The Scandinavian Foundation for Immunology.)

The acoustical features of kettledrums have been analyzed by means of modal analysis and acoustic radiation (p/v ratio) measurements. Modal analysis of two different kettledrums was undertaken, exciting the system both by a hammer and a shaker. Up to 15 vibrational modes were clearly identified. Acoustic radiation was studied using two ways. Based on previous experiments of other researchers, a new parameter, called intensity of acoustic radiation (IAR), has been defined and measured. Results show a strict relationship between IAR and the frequency response function (FRF, which is the v/F ratio), and IAR also strongly relates the modal pattern to acoustic radiation. Finally, IAR is proposed for vibro-acoustical characterization of kettledrums and other musical instruments such as strings, pianos, and harpsichords.