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].

An Ontology-Centric Approach to Sensor-Mission Assignment

Abstract: Sensor-mission assignment involves the allocation of sensor and other information-providing resources to missions in order to cover the information needs of the individual tasks in each mission. This is an important problem in the intelligence, surveillance, and reconnaissance (ISR) domain, where sensors are typically over-subscribed, and task requirements change dynamically. This paper approaches the sensor-mission assignment problem from a Semantic Web perspective: the core of the approach is a set of ontologies describing mission tasks, sensors, and deployment platforms. Semantic reasoning is used to recommend collections of types of sensors and platforms that are known to be "fit-for-purpose" for a particular task, during the mission planning process. These recommended solutions are used to constrain a search for available instances of sensors and platforms that can be allocated at mission execution-time to the relevant tasks. An interface to the physical sensor environment allows the instances to be configured to operate as a coherent whole and deliver the necessary data to users. Feedback loops exist throughout, allowing re-planning of the sensor-task fitness, reallocation of instances, and reconfiguration of the sensor network.

Characterisation of the surface chemistry of magnesium exposed to the ambient atmosphere

Abstract: The changes in the surface chemistry of the oxidised surface of evaporated magnesium metal stored in the ambient atmosphere are studied with water contact angle (WCA) measurement, polarisation-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) and X-ray photoelectron spectroscopy (XPS). Upon exposure to the ambient atmosphere, the surface picks up volatile organic compounds (VOC), which cause a significant increase in the WCA values. The PM-IRRAS and XPS analyses indicate that the adsorbates contain hydrocarbons, carboxylates and carbonate functionalities. After long ambient storage times, the composition of the carbon-containing functionalities on the surface changes significantly. This change could be caused by the build-up and/or surface-catalysed oxidation of adsorbed organic species. Thickening of the air-formed oxide/hydroxide layer was also noted, ascribed to the reaction of adsorbed atmospheric moisture with the magnesium surface. Copyright © 2006 John Wiley & Sons, Ltd.

Immunogenicity of Recombinant Protective Antigen and Efficacy against Aerosol Challenge with Anthrax

Abstract: Immunization with a recombinant form of the protective antigen (rPA) from Bacillus anthracis has been carried out with rhesus macaques. Rhesus macaques immunized with 25 mug or more of B. subtilis-expressed rPA bound to alhydrogel had a significantly increased immunoglobulin G (IgG) response to rPA compared with macaques receiving the existing licensed vaccine from the United Kingdom (anthrax vaccine precipitated [AVP]), although the isotype profile was unchanged, with bias towards the IgG1 and IgG2 subclasses. Immune macaque sera from all immunized groups contained toxin-neutralizing antibody and recognized all the domains of PA. While the recognition of the N terminus of PA (domains 1 to 3) was predominant in macaques immunized with the existing vaccines (AVP and the U.S. vaccine anthrax vaccine adsorbed), macaques immunized with rPA recognized the N- and C-terminal domains of PA. Antiserum derived from immunized macaques protected macrophages in vitro against the cytotoxic effects of lethal toxin. Passive transfer of IgG purified from immune macaque serum into naive A/J mice conferred protection against challenge with B. anthracis in a dose-related manner. The protection conferred by passive transfer of 500 mug macaque IgG correlated significantly (P = 0.003; r = 0.4) with the titers of neutralizing antibody in donor macaques. Subsequently, a separate group of rhesus macaques immunized with 50 mug of Escherichia coli-derived rPA adsorbed to alhydrogel was fully protected against a target dose of 200 50% lethal doses of aerosolized B. anthracis. These data provide some preliminary evidence for the existence of immune correlates of protection against anthrax infection in rhesus macaques immunized with rPA.