204 research outputs found
Decoying Coyotes with Dogs
Decoy dogs, used in conjunction with a predator call or coyote howl, are an effective technique to reduce coyote depredation on domestic sheep ranges during the spring and summer when coyotes are highly territorial and aggressively protect their young and den area. Trained decoy dogs, when chased by coyotes, return to their owner bringing the coyotes into shooting range. The type of dogs used successfully for this work is discussed
Decoying Coyotes with Dogs
Decoy dogs, used in conjunction with a predator call or coyote howl, are an effective technique to reduce coyote depredation on domestic sheep ranges during the spring and summer when coyotes are highly territorial and aggressively protect their young and den area. Trained decoy dogs, when chased by coyotes, return to their owner bringing the coyotes into shooting range. The type of dogs used successfully for this work is discussed
An Examination of Significant Issues in Naval Maintenance
AbstractThis paper summarises qualitative research undertaken within the “In-Service” stage of the lifecycle of Royal Navy surface ships and submarines. Whilst In-Service, Royal Navy vessels will typically cycle through three phases, i.e. Tasking, Upkeep and Regeneration. A series of semi-structured recorded interviews conducted with key stakeholders in each phase identifies and highlights common issues encountered whilst In-Service. Having identified common issues, e.g. risk, obsolescence, manpower availability, etc. additional interviews were undertaken to triangulate the results with other safety critical companies operating and maintaining complex systems, i.e. a power company operating an advanced gas-cooled nuclear reactor, rail infrastructure and Europe's largest regional airline
Characterisation of the S. Typhimurium σE regulon
The extracytoplasmic stress response (ESR) of the Enterobacteriacea consists mainly of two partially overlapping pathways, one regulated by the alternative sigma factor, σE encoded for by rpoE and the other by the two component regulator cpxRA. This thesis mainly focuses on the regulated arm of the ESR but does discuss potential crosstalk between these two systems. Characterisation of the rpoE regulon in E. coli has been performed using a number of methods, each of which identified different genes (Dartigalongue, Missiakas, and Raina, 2001;Rezuchova et al., 2003). RpoE has been described as essential for survival of E. coli laboratory strains (De Las, Connolly, and Gross, 1997a), but deletion of the rpoE structural gene in S. Typhimurium is not lethal (Humphreys et al, 1999). However the S. Typhimurium rpoE mutation is critical for survival in vivo, as it appears to be for a number of pathogenic bacteria (Humphreys et al, 1999;Hild et al., 2000;Craig, Nobbs, and High, 2002;Heungens, Cowles, and Goodrich-Blair, 2002;Kovacikova and Skorupski, 2002;Testerman et al, 2002;Heusipp, Schmidt, and Miller, 2003). Considering the different locations and microenvironments encountered by these different pathogens it is likely that each of the rpoE regulons may contain different genes. To establish which are important for S. Typhimurium our collaborators and I have utilised a number of techniques to identify RpoE regulated genes. In collaboration with the group of Dr. Jan Kormanec, Slovakia, a two plasmid system has been utilised. We have also been given access to the S. Typhimurium microarrays at the Institute of Food Research, and used a promoter consensus search derived from known σE regulated genes to search the S. Typhimurium genome for putatively σE regulated genes. With a combination of these techniques we have identified a number of putatively σE regulated genes, and have selected a portion of these to be mutated with lambda red mutagenesis and characterised both in vitro and in vivo
The Salmonella specific, σE-regulated, STM1250 and AgsA, function with the sHsps IbpA and IbpB, to counter oxidative stress and survive macrophage killing
The host presents an array of environments which induce bacterial stress including changes in pH, antimicrobial compounds and reactive oxygen species. The bacterial envelope sits at the interface between the intracellular and extracellular environment and its maintenance is essential for Salmonella cell viability under a range of conditions, including during infection. In this study, we aimed to understand the contribution of the σH- and σE-regulated small heat shock proteins IbpA, IbpB, and AgsA and the putative σE-regulated stress response protein STM1250 to the Salmonella envelope stress response. Due to shared sequence identity, regulatory overlap, and the specificity of STM1250 and AgsA to Salmonella sp., we hypothesized that functional overlap exists between these four stress response proteins, which might afford a selective advantage during Salmonella exposure to stress. We present here new roles for three small heat shock proteins and a putative stress response protein in Salmonella that are not limited to heat shock. We have shown that, compared to WT, a quadruple mutant is significantly more sensitive to hydrogen peroxide, has a lower minimum bactericidal concentration to the cationic antimicrobial peptide polymyxin B, and is attenuated in macrophages
Transcriptional and Environmental Control of Bacterial Denitrification and N2O Emissions
In oxygen-limited environments, denitrifying bacteria can switch from oxygen-dependent respiration to nitrate (NO3−) respiration in which the NO3− is sequentially reduced via nitrite (NO2−), nitric oxide (NO) and nitrous oxide (N2O) to dinitrogen (N2). However, atmospheric N2O continues to rise, a significant proportion of which is microbial in origin. This implies that the enzyme responsible for N2O reduction, nitrous oxide reductase (NosZ), does not always carry out the final step of denitrification either efficiently, or in synchrony with the rest of the pathway. Despite a solid understanding of the biochemistry underpinning denitrification, there is a relatively poor understanding of how environmental signals and respective transcriptional regulators control expression of the denitrification apparatus. This mini-review will describe the current picture for transcriptional regulation of denitrification in the model bacterium, Paracoccus denitrificans, highlighting differences in other denitrifying bacteria where appropriate, as well as gaps in our understanding. Alongside this, the emerging role of small regulatory RNAs (sRNAs) in regulation of denitrification will be discussed. We will conclude by speculating how this information, aside from providing a better understanding of the denitrification process, can be translated into development of novel greenhouse gas mitigation strategies
Novel Inducers of the Envelope Stress Response BaeSR in Salmonella Typhimurium: BaeR Is Critically Required for Tungstate Waste Disposal
The RpoE and CpxR regulated envelope stress responses are extremely important for SalmonellaTyphimurium to cause infection in a range of hosts. Until now the role for BaeSR in both the Salmonella Typhimurium response to stress and its contribution to infection have not been fully elucidated. Here we demonstrate stationary phase growth, iron and sodium tungstate as novel inducers of the BaeRregulon, with BaeR critically required for Salmonella resistance to sodium tungstate. We show that functional overlap between the resistance nodulation-cell division (RND) multidrug transporters, MdtA, AcrD and AcrB exists for the waste disposal of tungstate from the cell. We also point to a role for enterobactinsiderophores in the protection of enteric organisms from tungstate, akin to the scenario in nitrogen fixing bacteria. Surprisingly, BaeR is the first envelope stress response pathway investigated in S. Typhimurium that is not required for murine typhoid in either ityS or ityR mouse backgrounds. BaeR is therefore either required for survival in larger mammals such as pigs or calves, an avian host such as chickens, or survival out with the host altogether where Salmonella and related enterics must survive in soil and water
Recommended from our members
Lexical organization in deaf children who use British Sign Language: Evidence from a semantic fluency task
We adapted the semantic fluency task into British Sign Language (BSL). In Study 1, we present data from twenty-two deaf signers aged four to fifteen. We show that the same ‘cognitive signatures’ that characterize this task in spoken languages are also present in deaf children, for example, the semantic clustering of responses. In Study 2, we present data from thirteen deaf children with Specific Language Impairment (SLI) in BSL, in comparison to a subset of children from Study 1 matched for age and BSL exposure. The two groups' results were comparable in most respects. However, the group with SLI made occasional word-finding errors and gave fewer responses in the first 15 seconds. We conclude that deaf children with SLI do not differ from their controls in terms of the semantic organization of the BSL lexicon, but that they access signs less efficiently
Naval Surface Ship In-service Information Exploitation
Abstract The Royal Navy operates a fleet of complex modern warships and submarines each comprising a system of systems often in harsh and potentially volatile environments. The maintenance of surface vessels is primarily undertaken by Babcock and BAe Systems in an alliance with the Ministry of Defence. The Ministry of Defence system engineering lifecycle is known as CADMID, this details the six phases of a projects' lifecycle from Concept through to Disposal. The "In-Service" phase of a naval vessel will typically constitute 70% of the artefact's through-life cost. During the "In-Service" phase the number and involvement of stakeholders will vary as the vessel cycles through Tasking, Upkeep and Regeneration. The paper considers the key stakeholders and their participation in each cyclical mode. Information to be exploited will be subject to two discrete drivers, firstly the information available for exploitation as a consequence the vessels' current cyclical mode, secondly, the characteristics of the information source.
Nitrous oxide metabolism in nitrate-reducing bacteria: Physiology and regulatory mechanisms
Nitrous oxide (N2O) is an important greenhouse gas (GHG) with substantial global warming potential and also contributes to ozone depletion through photochemical nit- ric oxide (NO) production in the stratosphere. The negative effects of N2O on climate and stratospheric ozone make N2O mitigation an international challenge. More than 60% of global N2O emissions are emitted from agricultural soils mainly due to the appli- cation of synthetic nitrogen-containing fertilizers. Thus, mitigation strategies must be developed which increase (or at least do not negatively impact) on agricultural effi- ciency whilst decrease the levels of N2O released. This aim is particularly important in the context of the ever expanding population and subsequent increased burden on the food chain. More than two-thirds of N2O emissions from soils can be attributed to bacterial and fungal denitrification and nitrification processes. In ammonia-oxidizing bacteria, N2O is formed through the oxidation of hydroxylamine to nitrite. In denitrifiers, nitrate is reduced to N2 via nitrite, NO and N2O production. In addition to denitrification, respiratory nitrate ammonification (also termed dissimilatory nitrate reduction to ammonium) is another important nitrate-reducing mechanism in soil, responsible for the loss of nitrate and production of N2O from reduction of NO that is formed as a by-product of the reduction process. This review will synthesize our current understand- ing of the environmental, regulatory and biochemical control of N2O emissions by nitrate-reducing bacteria and point to new solutions for agricultural GHG mitigation
- …