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].

Testing the Effects of 3D Multiple Object Tracking Training on Near, Mid and Far Transfer.

Abstract: Cognitive training aims to develop domain general mental abilities to support functions like decision making, multitasking and performance under pressure. Research to date has indicated that cognitive training likely aids performance on lab-based cognitive tests, but there has been little demonstration of transfer to tasks representative of real-world high performance environments. This study aimed to assess transfer from a cognitive training intervention to near and mid-level transfer tasks, plus a far transfer test representative of real-world multitasking in a military environment. 84 participants were randomised to four independent training groups, using NeuroTracker, a cognitive training task based on 3D object tracking. There was no evidence for near transfer (to another object tracking task) or for far transfer to a route monitoring task designed to replicate real-world multitasking. There may, however, have been some improvement in working memory performance as a result of training. These findings raise further questions about whether domain general cognitive training will transfer to real-world performance. Effective uses of cognitive training may require more task specific training targeting mid-level transfer effects.

Diffusion-based and creep continuum damage modelling of crack formation during high temperature oxidation of ZrN ceramics

Abstract: ZrN’s good thermal and mechanical properties make it suitable for many commercial applications including in nuclear fuels. An understanding of its oxidation behaviour is essential to prevent catastrophic failures and ensure it is employed safely in nuclear power plants. Based on available experimental results on oxidation of ZrN in the temperature range 1173–1373 K, a continuum damage mechanics-based combined creep and time-dependent material oxidation model is proposed. The model allows for the development of a surface oxide layer combined with damage due to creep under an applied load. A representative grain structure has been modelled according to ZrN microstructural characteristics in order to allow intergranular cracking and individual oxidation damage rates for grains and grain boundaries. The proposed damage model is implemented as a user subroutine and runs in a coupled temperature-displacement analysis using the commercial finite element software Abaqus. Available data on ZrN are used to validate the capability of the model to predict oxidation damage in ceramics at high temperatures.

The Cystovirus phi6 as a simulant for Venezuelan equine encephalitis virus

Abstract: Innocuous organisms able to simulate the properties of pathogens are necessary so that the behaviour of pathogenic microorganisms in the environment may be understood. This is essential if we are to understand the epidemiology and consequence management of airborne infection, whether natural or the result of a deliberate release. The coliphage MS2 has been widely used as a simulant for mammalian viruses, although it bears little structural or biochemical similarity to the agents of interest. The well-characterised bacteriophage phi6 (host Pseudomonas syringae) is closer in size and complexity to pathogenic viruses, notably the Alphavirus Venezuelan equine encephalitis virus (VEEV) because the virion has surface structures and is bounded by a lipid envelope. Here, we show for phi6 that the assay is simple and precise and that the infectivity is stable in buffers and under conditions used for aerobiology experiments, it is retained after aerosolisation and sampling. Finally, phi6 aerosol was generated into a re-circulating wind tunnel where a stable and acceptable level of viability was maintained. Phi6 may prove a useful simulant for VEEV and possibly for other lipid-containing viruses as well.

Dysregulation of the actin scavenging system and inhibition of DNase activity following severe thermal injury.

Abstract: Background: Circulating cell-free DNA (cfDNA) is not found in healthy subjects, but is readily detected after thermal injury and may contribute to the risk of multiple organ failure. The hypothesis was that a postburn reduction in DNase protein/enzyme activity could contribute to the increase in cfDNA following thermal injury. Methods: Patients with severe burns covering at least 15 per cent of total body surface area were recruited to a prospective cohort study within 24 h of injury. Blood samples were collected from the day of injury for 12 months. Results: Analysis of blood samples from 64 patients revealed a significant reduction in DNase activity on days 1–28 after injury, compared with healthy controls. DNase protein levels were not affected, suggesting the presence of an enzyme inhibitor. Further analysis revealed that actin (an inhibitor of DNase) was present in serum samples from patients but not those from controls, and concentrations of the actin scavenging proteins gelsolin and vitamin D-binding protein were significantly reduced after burn injury. In a pilot study of ten military patients with polytrauma, administration of blood products resulted in an increase in DNase activity and gelsolin levels. Conclusion: The results of this study suggest a novel biological mechanism for the accumulation of cfDNA following thermal injury by which high levels of actin released by damaged tissue cause a reduction in DNase activity. Restoration of the actin scavenging system could therefore restore DNase activity, and reduce the risk of cfDNA-induced host tissue damage and thrombosis.