A Genomic and Proteomic Investigation Into the <i>Clostridium botulinum</i> Neurotoxin Complex

Clostridium botulinum and some strains of C. baratii and C. butyricum produce one of the most potent toxins known to man, botulinum neurotoxin, and are responsible for the disease botulism. This severe neuroparalytic disease is the result of botulinum neurotoxin negotiating a complex path to the cholinergic nerve endings. There, it interferes with the release of excitatory neurotransmitters resulting in flaccid paralysis and if untreated, death. The neurotoxin, itself a multi-faceted protein, does not act alone but is produced as part of a large, hetero-multimeric complex with the associated non-toxic proteins. This complex, known to protect the toxin from acids and proteases in the gut, has recently been suggested to play a more active role in toxicity. Here, the proteins from the lesser-studied toxin complex type (the OrfX type) are shown for the first time to share sequence similarity and synteny with clusters of proteins that are co-localised with various putative toxin genes in diverse other species. The extracellular supernatant proteome of C. butyricum is characterised and mined for potential novel virulence factors, with metabolic cost of extracellular protein being highlighted as a potential marker of virulence associated extracellular proteins. The supernatant of 22 clinical strains of C. butyricum were investigated for the presence of the toxin complex; all toxin complex components were identified in the majority of strains indicating the importance of these proteins in the causation of botulism. A relationship between OrfX-encoding strains and infant botulism was also uncovered in clinical strains from the UK. Hypotheses to explain this association are explored. Finally, the transcriptome of C. butyricum was investigated using RNA-sequencing. This uncovered a complex and diverse picture of transcription in C. butyricum and raised questions as to the role of the alternative sigma factor BotR in the regulation of bont

A Versatile Wireless Network Protocol for Spectrum Sharing with Passive Radio Services

With the proliferation of wideband active services in bands shared with passive receivers for remote sensing and radio astronomy, new methods are needed for deconflicting active and passive users. We have developed a technique for active/passive user coordination that is compatible with essentially any existing wireless communications protocol. The passive user transmits an on-off keying modulated signal that can be detected by active radios using simple channel power estimates. Using off-the-shelf WiFi and LoRa hardware and on a software defined radio implementation of LTE, we show that Dynamic Passive to Active Spectrum Sharing (DPASS) is effective on a wide range of frequencies and physical layer implementations. We validate the protocol using these three technologies by demonstrating that each device receives a DPASS packet and dynamically takes an appropriate spectrum coordination action, including shutting off transmissions or switching frequencies.Comment: 9 pages, 8 figure

Association of Researchers in Construction Management

Despite the wealth of knowledge and information on off-site manufacturing systems, current decision making models do not adequately provide a clear cut choice between using offsite manufacture of building elements and onsite in-situ construction, especially at the pre-construction stage. This paper describes the development of a Decision Evaluation Model (DEM) that provides this opportunity particularly for house building projects. The primary objective of the model is to improve the quality of information on which the decision is based. Having carried out an extensive literature review, primary research data and information was collected from 30 structured interviews, questionnaires completed by 30 selected respondents, and 30 case studies made up of 15 manufacturing &apos;offsite&apos; projects and 15 projects using &apos;onsite&apos; construction methods. A robust set of factors have been identified, measured and ranked according to their significance in the decision. Using these factors, a methodology has been developed to measure and evaluate the characteristics of a project, which forms the core of the DEM. The developed model enables decision makers to clearly establish whether to use offsite or onsite construction as a construction strategy. The DEM model provides the opportunity to assist the construction practitioners and clients in making decisions based on adequate data and predictable outcomes against any given project within its environment