Displacement demand for nonlinear static analyses of masonry structures: Critical review and improved formulations

This paper discusses different formulations for calculating earthquake‐induced displacement demands to be associated with nonlinear static analysis procedures for the assessment of masonry structures. Focus is placed on systems with fundamental periods between 0.1 and 0.5 s, for which the inelastic displacement amplification is usually more pronounced. The accuracy of the predictive equations is assessed based on the results from nonlinear time‐history analyses, carried out on single‐degree‐of‐freedom oscillators with hysteretic force–displacement relationships representative of masonry structures. First, the study demonstrates some limitations of two established approaches based on the equivalent linearization concept: the capacity spectrum method of the Dutch guidelines NPR 9998‐18, and its version outlined in FEMA 440, both of which overpredict maximum displacements. Two codified formulations relying on inelastic displacement spectra are also evaluated, namely the N2 method of Eurocode 8 and the displacement coefficient method of ASCE 41‐17: the former proves to be significantly unconservative, while the latter is affected by excessive dispersion. A non‐iterative procedure, using an equivalent linear system with calibrated optimal stiffness and equivalent viscous damping, is then proposed to overcome some of the problems identified earlier. A recently developed modified N2 formulation is shown to improve accuracy while limiting the dispersion of the predictions

Macroelement Numerical Simulation of the Seismic Response of a Timber-Retrofitted Masonry Pier

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Macroelement Numerical Simulation of the Seismic Response of a Timber-Retrofitted Masonry Pier

In the North-East part of The Netherlands, induced seismicity due to gas extraction is affecting a local building stock consisting mainly of unreinforced masonry (URM) houses not designed for earthquake resistance. Experimental and numerical studies conducted at EUCENTRE, Pavia (Italy), have demonstrated that buildings with URM cavity-walls structural systems are among the most vulnerable existing Dutch construction typologies. A light and reversible retrofit system made of timber frames and oriented-strands boards was then designed and tested to increase the in-plane and out-of-plane capacities of masonry piers and to enhance their connections with the floor diaphragms. The development of modelling approaches able to simulate the influence of the retrofit system is of fundamental importance for future applications to real-case existing buildings and for vulnerability studies on different building stocks. Based on two quasi-static in-plane shear-compression tests on two full-scale masonry piers, one in bare and one in retrofitted configuration, a specific macroelement was calibrated to simulate the bare pier lateral response and the effects of the retrofit on the in-plane flexural and shear capacities. This paper discusses the adopted modelling strategies and the comparison between numerical and experimental results

A new fireworm (Amphinomidae) from the Cretaceous of Lebanon identified from three-dimensionally preserved myoanatomy

© 2015 Parry et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article

Antiepileptic drugs’ tolerability and safety – a systematic review and meta-analysis of adverse effects in dogs

<p>Various anti-epileptic drugs (AEDs) are used for the management of idiopathic epilepsy (IE) in dogs. Their safety profile is an important consideration for regulatory bodies, owners and prescribing clinicians. However, information on their adverse effects still remains limited with most of it derived from non-blinded non-randomized uncontrolled trials and case reports.</p><p><span>This poster won third place, which was presented at the Veterinary Evidence Today conference, Edinburgh November 1-3, 2016. </span></p><br /> <img src="https://www.veterinaryevidence.org/rcvskmod/icons/oa-icon.jpg" alt="Open Access" /

The safety of over-the-counter niacin. A randomized placebo-controlled trial [ISRCTN18054903]

BACKGROUND: Niacin is widely available over the counter (OTC). We sought to determine the safety of 500 mg immediate release niacin, when healthy individuals use them as directed. METHODS: 51 female and 17 male healthy volunteers (mean age 27 years SD 4.4) participated in a randomized placebo-controlled blinded trial of a single dose of an OTC, immediate-release niacin 500 mg (n = 33), or a single dose of placebo (n = 35) on an empty stomach. The outcomes measured were self-reported incidence of flushing and other adverse effects. RESULTS: 33 volunteers on niacin (100%) and 1 volunteer on placebo (3%) flushed (relative risk 35, 95% confidence interval (CI) 6.8–194.7). Mean time to flushing on niacin was 18.2 min (95% CI: 12.7–23.6); mean duration of flushing was 75.4 min (95% CI: 62.5–88.2). Other adverse effects occurred commonly in the niacin group: chills (51.5% vs. 0%, P < .0001), generalized pruritus (75% vs. 0%, P = <.001), gastrointestinal upset (30% vs. 3%, P = .005), and cutaneous tingling (30% vs. 0%, P = <.001). Six participants did not tolerate the adverse effects of niacin and 3 required medical attention. CONCLUSION: Clinicians counseling patients about niacin should alert patients not only about flushing but also about gastrointestinal symptoms, the most severe in this study. They should not trust that patients would receive information about these side effects or their prevention (with aspirin) from the OTC packet insert