Should we design buildings for lower-probability earthquake motion?

On February 22, 2011, an earthquake of magnitude 6. 3 occurred very near to the city of Christchurch, New Zealand. The consequence came as a shock to many seismologists and earthquake engineers as New Zealand is known as the homeland of modern earthquake-resistant design techniques. After the earthquake, the focus of discussion has been on the collapse of buildings, while few queried the adequacy of design requirements. Importantly, similar "inadequacy" seems to repeat all around the world more frequently than expected. Hence, the question statement in the title concerns not only Christchurch, but anywhere in the world. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

A checking method for probabilistic seismic-hazard assessment: case studies on three cities

The conventional Cornell's source-based approach of probabilistic seismic-hazard assessment (PSHA) has been employed all around the world, whilst many studies often rely on the use of computer packages such as FRISK (McGuire FRISK-a computer program for seismic risk analysis. Open-File Report 78-1007, United States Geological Survey, Department of Interior, Washington 1978) and SEISRISK III (Bender and Perkins SEISRISK III-a computer program for seismic hazard estimation, Bulletin 1772. United States Geological Survey, Department of Interior, Washington 1987). A "black-box" syndrome may be resulted if the user of the software does not have another simple and robust PSHA method that can be used to make comparisons. An alternative method for PSHA, namely direct amplitude-based (DAB) approach, has been developed as a heuristic and efficient method enabling users to undertake their own sanity checks on outputs from computer packages. This paper experiments the application of the DAB approach for three cities in China, Iran, and India, respectively, and compares with documented results computed by the source-based approach. Several insights regarding the procedure of conducting PSHA have also been obtained, which could be useful for future seismic-hazard studies. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

Regional differences in attenuation modelling for Eastern China

This paper describes the development of seismological models for three sub-regions within Eastern China. An important feature of the modelling is that two main types of local data were used to determine parameters for input into the seismological model. Shear wave velocity data was used in Step One of the procedure for deriving the upper crustal factors which are part of the seismological model. Two further steps were involved in incorporating the historical Intensity (MMI) data into the modelling. In Step Two, the simulated peak ground velocity (PGV) values were converted to MMI values, and site factor was calculated by dividing the inferred PGV value by the respective simulated PGV value for each given (short distance) earthquake scenario. In Step Three, the quality (Q) factor of the seismological model for each sub-region was calibrated in accordance with the criterion that site factors inferred from records of long distance earthquakes in the database match with the median site factor obtained in Step Two for short distance earthquakes. Importantly, the Q values obtained by this calibration method were highly consistent with Coda Q values (obtained for each sub-region from a previous study by Jin and Aki based on analysing records of local earth tremors). The calibrated Q values in combination with the developed crustal factors and geometrical attenuation factor constitute the regional seismological model for Eastern China. The seismological model so developed takes into account intra-regional differences and has been used to simulate strong ground motions by the stochastic method for assessing the potential seismic hazards in the region. © 2010 Elsevier Ltd.postprin

Failure of phylogeny inferred from multilocus sequence typing to represent bacterial phylogeny

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Primitive neuroectodermal adrenal gland tumour

Ewing's sarcoma, also called primitive neuroectodermal tumour of the adrenal gland, is extremely rare. Only a few cases have been reported in the literature. We report on a woman with adult-onset primitive neuroectodermal tumour of the adrenal gland presenting with progressive flank pain. Computed tomography confirmed an adrenal tumour with invasion of the left diaphragm and kidney. Radical surgery was performed and the pain completely resolved; histology confirmed the presence of primitive neuroectodermal tumour, for which she was given chemotherapy. The clinical presentation of this condition is non-specific, and a definitive diagnosis is based on a combination of histology, as well as immunohistochemical and cytogenic analysis. According to the literature, these tumours demonstrate rapid growth and aggressive behaviour but there are no well-established guidelines or treatment strategies. Nevertheless, surgery remains the mainstay of local disease control; curative surgery can be performed in most patients. Adjuvant chemoirradiation has been advocated yet no consensus is available. The prognosis of patients with primitive neuroectodermal tumours remains poor.published_or_final_versio

Normal 24-hour ambulatory proximal and distal gastroesophageal reflux parameters in Chinese.

OBJECTIVE: To quantify normal proximal and distal oesophageal acid parameters in healthy Chinese. DESIGN: Observational study. SETTING: University teaching hospital, Hong Kong. SUBJECTS AND METHODS: Twenty healthy adults who were not on medication and were free from gastrointestinal symptoms were recruited by advertisement. Ambulatory oesophageal acid (pH5 minutes, 4/0; and the longest single acid exposure episode, 11.2/3.0 minutes. CONCLUSION: Physiological gastroesophageal reflux occurs in healthy Chinese. These initial data provide a preliminary reference range that could be utilised by laboratories studying Chinese subjects.published_or_final_versio

A design spectrum model for flexible soil sites in regions of low-to-moderate seismicity

Design spectrum (DS) models in major codes of practice for structural design of buildings typically stipulate empirical site factors for each of the five, or six, site classes. Although the phenomenon of resonant like amplification behaviour of the structure caused by multiple wave reflections is well known, the potentials for such periodic amplification behaviour are not explicitly considered in code models. This is partly because of expert opinion that such effects are very "localised" in the frequency domain and can be suppressed readily by damping. However, investigations into the risk of collapse of non-ductile, and irregular structural systems, common in regions of low-to-moderate seismicity, revealed the extensive influence of periodic base excitations on flexible soil sites (with initial small-strain natural period T-i > 0.5 s). In this paper, an alternative DS model which addresses the important phenomenon of soil resonance without the need of computational site response analysis of the subsurface model of the site is introduced

Improved measurement of the reactor antineutrino flux and spectrum at Daya Bay

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