Defence Science and Technology Laboratory

About: Defence Science and Technology Laboratory is a government organization based out in Salisbury, United Kingdom. It is known for research contribution in the topics: Burkholderia pseudomallei & Francisella tularensis. The organization has 926 authors who have published 1242 publications receiving 30091 citations. The organization is also known as: Dstl & [dstl].

Temporal changes in ROTEM®-measured coagulability of citrated blood samples from coagulopathic trauma patients

Abstract: Background: Rotational thromboelastometry (ROTEM (R)) relies on citrated blood samples, which are regarded as biologically stable for up to 4 h after venepuncture. However, this recommendation is based on data from normal volunteers. The aim of this study was to evaluate possible temporal changes in the coagulability of blood samples from coagulopathic trauma patients.Patients and methods: This is a prospective series of 10 coagulopathic (maximum clot firmness, MCF < 40 mm) trauma patients. ROTEM (R) EXTEM (tissue factor activated) and FIBTEM (tissue factor activated, cytochalasin D inhibited) analyses were performed on samples obtained on admission, and after approximately 60 min of storage in an incubator, at 37 degrees C.Results: There were statistically significant differences between the median EXTEM MCF (22 mm vs 54 mm, p < 0.001) and alpha angle (30.5 vs 59.5 degrees, p = 0.004) of the analyses performed immediately after sampling, and 51 min (median) subsequently, but not coagulation time (CT, p = 0.133), clot formation time (p = 0.0625) or maximum lysis (ML, p = 0.154). There were also no differences in median FIBTEM MCF (p = 1.00) or CT (p = 0.877) between the immediate and delayed analyses.Conclusions: Repeated ROTEM (R) EXTEM analysis of citrated samples from coagulopathic trauma patients shows a spontaneous improvement in coagulability with time. The absence of parallel changes on FIBTEM analysis suggests that this effect may be due to a change in platelet function. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.

Fate of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX) on soil following accelerant-based fire and liquid decontamination.

Abstract: In the event of alleged use of organophosphorus nerve agents, all kinds of environmental samples can be received for analysis. These might include decontaminated and charred matter collected from the site of a suspected chemical attack. In other scenarios, such matter might be sampled to confirm the site of a chemical weapon test or clandestine laboratory decontaminated and burned to prevent discovery. To provide an analytical capability for these contingencies, we present a preliminary investigation of the effect of accelerant-based fire and liquid decontamination on soil contaminated with the nerve agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX). The objectives were (a) to determine if VX or its degradation products were detectable in soil after an accelerant-based fire promoted by aviation fuel, including following decontamination with Decontamination Solution 2 (DS2) or aqueous sodium hypochlorite, (b) to develop analytical methods to support forensic analysis of accelerant-soaked, decontaminated and charred soil and (c) to inform the design of future experiments of this type to improve analytical fidelity. Our results show for the first time that modern analytical techniques can be used to identify residual VX and its degradation products in contaminated soil after an accelerant-based fire and after chemical decontamination and then fire. Comparison of the gas chromatography–mass spectrometry (GC-MS) profiles of VX and its impurities/degradation products from contaminated burnt soil, and burnt soil spiked with VX, indicated that the fire resulted in the production of diethyl methylphosphonate and O,S-diethyl methylphosphonothiolate (by an unknown mechanism). Other products identified were indicative of chemical decontamination, and some of these provided evidence of the decontaminant used, for example, ethyl 2-methoxyethyl methylphosphonate and bis(2-methoxyethyl) methylphosphonate following decontamination with DS2. Sample preparation procedures and analytical methods suitable for investigating accelerant and decontaminant-soaked soil samples are presented. VX and its degradation products and/or impurities were detected under all the conditions studied, demonstrating that accelerant-based fire and liquid-based decontamination and then fire are unlikely to prevent the retrieval of evidence of chemical warfare agent (CWA) testing. This is the first published study of the effects of an accelerant-based fire on a CWA in environmental samples. The results will inform defence and security-based organisations worldwide and support the verification activities of the Organisation for the Prohibition of Chemical Weapons (OPCW), winner of the 2013 Nobel Peace Prize for its extensive efforts to eliminate chemical weapons.

Validation of the mission-based approach to representing command and control in simulation models of conflict

Abstract: There is a need to represent military command and control in closed-form simulation models of conflict, in order to compare investment in such capability with alternative defence investments. This paper considers such representation of military command and control in the context of embodied cognitive science. This means that we represent such processes in terms of both decision-making and resultant behaviour. Previous work leads to the view that such a representation can be captured by a combination of deliberate (top down) planning and rapid (bottom up) planning. We have developed an approach on these lines as a way of representing human decision-making and behaviour in conflict. Here we show, by comparing simulation model results with real conflict situations, that our approach yields emergent force behaviour which is valid and representative. This thus increases our confidence that our representation of command and control in such simulation models is sufficient for our requirements.