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Unreinforced masonry (URM) buildings with cavity walls, typically constituted by the assembly of a loadbearing inner leaf weakly coupled to an outer veneer with no structural functions, are widely present in a number of regions exposed to tectonic or induced seismicity, including the Groningen province (The Netherlands), which has lately experienced low-intensity ground shaking due to natural gas extraction. Recently, experimental evidence has shown that the lack of seismic details, and, above all, the presence of large ground floor openings, makes these structures particularly vulnerable towards horizontal actions. In this endeavour, advanced discrete element models, developed within the framework of the Applied Element Method (AEM), are employed to investigate numerically the impact of ground floor openings percentage on the dynamic behaviour of cavity wall systems representative of the typical Dutch terraced houses construction, namely low-rise residential URM buildings with rigid floor diaphragms and timber roof. Firstly, the model is validated through comparison with a shake-table test of a full-scale building specimen, tested up to near-collapse. Then, a comprehensive numerical study, which featured several combinations of ground-floor openings and the application of various acceleration time-histories up to complete collapse, is undertaken. The ensuing results allowed a comparison of the fragility associated with each of the considered openings layouts, showing how the presence of large ground floor openings may significantly increase the seismic vulnerability of typical URM Dutch terraced houses. [ABSTRACT FROM AUTHOR]

The significant potential for human and economic losses arising from earthquakes affecting urban infrastructure has been demonstrated by many recent events such as, for example, L'Aquila (2009), Christchurch (2011) and Tohoku (2012). Within the current practice of seismic loss estimation in both academic and industry models, the modelling of spatial variability of the earthquake ground motion input across a region, and its corresponding influence upon portfolios of heterogeneous building types, may be oversimplified. In particular, the correlation properties that are well-known in observations of ground motion intensity measures ( IMs) may not always be fully represented within the probabilistic modelling of seismic loss. Using a case study based on the Tuscany region of Italy, the impacts of including spatially cross-correlated random fields of different ground motion IMs are appraised at varying spatial resolutions. This case study illustrates the impact on the resulting seismic loss when considering synthetic aggregated portfolios over different spatial scales. Inclusion of spatial cross-correlation of IMs into the seismic risk analysis may often result in the likelihood of observing larger (and in certain cases smaller) losses for a portfolio distributed over a typical city scale, when compared against simulations in which the cross-correlation is neglected. It can also be seen that the degree to which the spatial correlations and cross-correlations can impact upon the loss estimates is sensitive to the conditions of the portfolio, particularly with respect to the spatial scale, the engineering properties of the different building types within the portfolio and the heterogeneity of the portfolio with respect to the types. [ABSTRACT FROM AUTHOR]

Investigation of lower extremity pain is compromised by comorbid disorders that may interfere with conventional testing. To compare pedal ergometry with conventional treadmill testing. A prospective study was performed where patients presenting with a diagnosis of intermittent claudication were assessed by both methods of testing. Of 78 patients studied with both tests, no exercise-induced ankle pressure changes occurred in 26, two were unable to complete either test despite normal pressure measurements, while 24 had exercise-induced pressure drop detected by both tests. Of patients who completed pedal ergometry, 21 were unable to complete the treadmill test, 14 of whom had negative ergometry, while seven had a pressure drop detected by pedal ergometry. Three had pressure changes with pedal ergometry, but not with treadmill testing and two had pressure changes on the treadmill not reproduced by pedal ergometry. Pedal ergometer is more sensitive than treadmill testing in detecting arterial insufficiency, as indicated by a 20% or greater fall in ankle pressure, and more suitable in a subgroup of patients unable to tolerate conventional treadmill testing. [ABSTRACT FROM AUTHOR]