243 research outputs found

    Transcriptional and Environmental Control of Bacterial Denitrification and N2O Emissions

    Get PDF
    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

    Get PDF
    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

    Brown Marmorated Stink Bug [Halyomorpha halys (Stal)]

    Get PDF
    This fact sheet describes the brown marmorated stink bug, an invasive insect pest from eastern Asia. It includes a description of where it is found in Utah, host plants, crop injury and plant damage, general description of life stages, agricultural risks, monitoring, management, insecticides, and what to do if you find it

    The Samurai Wasp Brings New Hope in the Fight Against Brown Marmorated Stink But in Utah

    Get PDF
    This handout describes normal BMSB development and BMSB eggs parasitized by the Samauri wasp

    Common Stink Bugs of Utah

    Get PDF
    This fact sheet provides information of some of Utah\u27s commonly encountered stink bugs, including what they look like, where to find them, and other key identifying characteristics

    How Rapid is Rapid Prototyping? Analysis of ESPADON Programme Results

    Get PDF
    New methodologies, engineering processes, and support environments are beginning to emerge for embedded signal processing systems. The main objectives are to enable defence industry to field state-of-the-art products in less time and with lower costs, including retrofits and upgrades, based predominately on commercial off the shelf (COTS) components and the model-year concept. One of the cornerstones of the new methodologies is the concept of rapid prototyping. This is the ability to rapidly and seamlessly move from functional design to the architectural design to the implementation, through automatic code generation tools, onto real-time COTS test beds. In this paper, we try to quantify the term “rapid†and provide results, the metrics, from two independent benchmarks, a radar and sonar beamforming application subset. The metrics show that the rapid prototyping process may be sixteen times faster than a conventional process

    Parasitoid Wasps of the Invasive Brown Marmorated Stink Bug in Utah

    Get PDF
    The brown marmorated stink bug (BMSB, Halyomorpha halys Stål), an invasive insect from eastern Asia, is causing nuisance problems and agricultural damage in northern Utah. Insecticide applications to control this pest are not sustainable, and therefore the focus is on biological control through the use of parasitoid wasps that sting and kill stink bug eggs. Surveys are underway in Utah to search for Samurai wasp (Trissolcus Japonicus [Ashmead]), a parasitoid wasp native to BMSB’s home range that has been found in 12 U.S. States, and is highly effective at killing BMSB eggs. While Samurai wasp has not been found, surveys have revealed 11 species of native parasitoid wasps in two families that are potentially contributing to the biological control of BMSB in Utah. Surveys will continue to search for Samurai wasp. If found, it can be reared and redistributed to assist with the biological control of BMSB. We herein review the different groups of wasps attacking BMSB in Utah, and offer identification characteristics and survey methods to better monitor for parasitoid wasps in the field

    Multipole Moments in the Effective Fragment Potential Method

    Get PDF
    In the effective fragment potential (EFP) method the Coulomb potential is represented using a set of multipole moments generated by the distributed multipole analysis (DMA) method. Misquitta, Stone, and Fazeli recently developed a basis space-iterated stockholder atom (BS-ISA) method to generate multipole moments. This study assesses the accuracy of the EFP interaction energies using sets of multipole moments generated from the BS-ISA method, and from several versions of the DMA method (such as analytic and numeric grid-based), with varying basis sets. Both methods lead to reasonable results, although using certain implementations of the DMA method can result in large errors. With respect to the CCSD­(T)/CBS interaction energies, the mean unsigned error (MUE) of the EFP method for the S22 data set using BS-ISA–generated multipole moments and DMA-generated multipole moments (using a small basis set and the analytic DMA procedure) is 0.78 and 0.72 kcal/mol, respectively. The MUE accuracy is on the same order as MP2 and SCS-MP2. The MUEs are lower than in a previous study benchmarking the EFP method without the EFP charge transfer term, demonstrating that the charge transfer term increases the accuracy of the EFP method. Regardless of the multipole moment method used, it is likely that much of the error is due to an insufficient short-range electrostatic term (i.e., charge penetration term), as shown by comparisons with symmetry-adapted perturbation theory

    Genome-Wide Discovery of Putative sRNAs in Paracoccus denitrificans Expressed under Nitrous Oxide Emitting Conditions

    Get PDF
    Nitrous oxide (N2O) is a stable, ozone depleting greenhouse gas. Emissions of N2O into the atmosphere continue to rise, primarily due to the use of nitrogen-containing fertilizers by soil denitrifying microbes. It is clear more effective mitigation strategies are required to reduce emissions. One way to help develop future mitigation strategies is to address the currently poor understanding of transcriptional regulation of the enzymes used to produce and consume N2O. With this ultimate aim in mind we performed RNA-seq on a model soil denitrifier, Paracoccus denitrificans, cultured anaerobically under high N2O and low N2O emitting conditions, and aerobically under zero N2O emitting conditions to identify small RNAs (sRNAs) with potential regulatory functions transcribed under these conditions. sRNAs are short (∼40–500 nucleotides) non-coding RNAs that regulate a wide range of activities in many bacteria. Hundred and sixty seven sRNAs were identified throughout the P. denitrificans genome which are either present in intergenic regions or located antisense to ORFs. Furthermore, many of these sRNAs are differentially expressed under high N2O and low N2O emitting conditions respectively, suggesting they may play a role in production or reduction of N2O. Expression of 16 of these sRNAs have been confirmed by RT-PCR. Ninety percent of the sRNAs are predicted to form secondary structures. Predicted targets include transporters and a number of transcriptional regulators. A number of sRNAs were conserved in other members of the α-proteobacteria. Better understanding of the sRNA factors which contribute to expression of the machinery required to reduce N2O will, in turn, help to inform strategies for mitigation of N2O emissions

    Design Factors for a Successful Shared Street Space (SSS) Design

    Get PDF
    The concept of Shared Space Street Shared Space Street (SSS) has the potential to bring many benefits to a city. Those include promotion of social interaction, the connectivity within the city for both vehicles and pedestrians, active engagement of the people with the space, walkability, vitality and street livability, better economic wealth and alike. These factors work together to improve livability, vitality of street and indirectly bring economic wealth to municipalities through increasing the footfall to shops, enhancing the health and safety of the locality and increasing the property values. Hence, this clearly is a consideration for strategic property management and relevant professionals. However, This concept has also been criticized for its practical issues when implemented in some parts of the world. Such issues include difficulties faced by aged people and people with disabilities, harassment faced by the cyclists, etc. This paper explores the methods and approaches that can be used to harness potential advantages of the SSS concept and to overcome its practical issues and criticisms through a detail evaluation of design driven use of space in three case studies within United Kingdom. Finally, this paper proposes a set of design factors which can be applied to a SSS design in order to ensure a successful implementation
    • …
    corecore