Operational Flexibility of Future Generation Portfolios Using High Spatial- and Temporal-Resolution Wind Data

Increasing amounts of variable renewable energy sources will cause fundamental and structural changes to thermal power plant operating regimes. Maintaining key reserve requirements will lead to an increase in power plant start-ups and cycling operations for some units. An enhanced unit commitment model with energy storage and flexible CO2 capture is formulated. High-resolution on-/offshore wind data for the U.K., and probabilistic wind power forecast, model wind imbalances at operational timescales. The strategic use of flexible CO2 capture and energy storage helps maintain reserve levels, decreasing power plant cycling operations and wind curtailment. A temporally explicit variability assessment of net demand illustrates the generation flexibility requirements and the nonlinear impacts of increasing wind capacity on power plant operating regimes

Identification and sequencing of a novel insertion sequence, IS1471, in Burkholderia cepacia strain 2a

A novel insertion sequence (IS), IS1471, has been identified which is inserted into IS element IS1071 possessed by plasmid pTJB1 in Burkholderia cepacia strain 2a. Nucleotide sequencing has revealed that IS1471 is 1112 bp in length and is flanked by 22/21-bp imperfect inverted repeats with a 3-bp duplication of the target sequence. IS1471 contains a single open reading frame encoding a putative polypeptide of 345 amino acids with molecular mass of 39 406 Da. Searches of DNA and protein sequence databases did not result in the detection of any homologous IS elements, suggesting that IS1471 is novel and may not belong to any known IS groups

Complete characterisation of Tn5530 from Burkholderia cepacia strain 2a (pIJB1) and studies of 2,4-dichlorophenoxyacetate uptake by the organism.

The complete genetic characterisation of Tn5530 in Burkholderia cepacia strain 2a (pIJB1) has been accomplished, indicating that it is a Tn3-like transposon with a complex structure bearing operons for the catabolism of 2,4-dichlorophenoxyacetate (2,4-D) and malonate. Tn5530 is terminated at both ends by the IS1071::IS1471 element and the 2,4-D- and malonate-dissimilatory operons are separated by a region encoding a putA and lrp gene and a gene encoding a chloride channel protein. The chloride channel protein may have a role in the expulsion of chloride ions liberated by the dissimilation of 2,4-D. In addition, a putative transposase with a high level of sequence similarity to those of plasmid pGH1 from Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. glycinea, and a transcription factor similar to those of the TetR family with low but significant levels of sequence similarity to those identified in a number of other organisms was observed. The entire Tn5530 sequence length, including the IS1071::IS1471 elements, was found to be 40,956bp, and pIJB1 was replicon-typed and otherwise characterised as being of the IncP-1beta subgroup, bearing merA and merD genes conferring resistance to mercuric chloride. The rate of uptake of 2,4-D by B. cepacia strain 2a was observed to proceed more readily at acid pH, suggesting involvement of the undissociated form of the compound. Uptake did not show saturation kinetics, was concentration-dependent, and appeared to occur in two stages; an initial accumulation followed by a linear second phase. Uptake could be inhibited by sodium azide but not by arsenate, N,N(')-dicyclohexylcarbodi-imide (DCCD) or carbonylcyanide m-chlorophenyl-hydrazone (CCCP) suggesting that it is not energy-dependent

2,4-Dichlorophenoxyacetate/alpha-ketoglutarate dioxygenases from Burkholderia cepacia 2a and Ralstonia eutropha JMP134

2,4-Dichlorophenoxyacetate (2,4-D)/alpha -ketoglutarate (alpha -KG) dioxygenase has been purified to apparent homogeneity from Burkholderia cepacia strain 2a, which utilizes 2.4-D as sole carbon source. The enzyme required ferrous ions, and was a homodimer composed of subunits having an M-r of similar to 32,000. The reaction catalysed consumed one mol each of 2,4-D, alpha -KG and dioxygen, with the production of one mol each of succinate, 2,4-dichlorophenol and glyoxylate. Maximum activity was exhibited at pH 7.8 and 25 degreesC, and reactivity was enhanced by the presence of ascorbate and cysteine. Mn2+, Zn2+, Cu2+ Fe3+ and Co2+ were inhibitory, and chemical modification of the dioxygenase revealed that thiol groups were essential for activity. The enzyme was active towards other substituted phenoxyacetates, but reacted most rapidly with 2,4-D. The apparent Michaelis constants for 2,4-D and alpha -KG were 109 and 8.9 muM, respectively. The properties of this enzyme are compared with those of the 2,4-D/alpha -KG dioxygenase from Ralstonia eutropha JMP134, which exhibits a differing N-terminal amino-acid sequence, and a different temperature 'optimum', pH optimum, substrate specificity and sensitivity to thiol-binding reagents

A novel plasmid pIJB1 possessing a putative 2,4-dichlorophenoxyacetate degradative transposon Tn5530 in Burkholderia cepacia strain 2a

A 102-kb plasmid, pIJB1, was isolated from Burkholderia cepacia strain 2a, which is able to use 2,4-dichlorophenoxyacetate (2,4-D) as a sole carbon source, and a physical map of the plasmid has been established. It was observed that spontaneous loss of a 37-kb fragment of the plasmid after growth in nonselective medium occurred, generating a plasmid of diminished size, pIJB2. The deletion event is concomitant with the loss of the 2,4-D dissimilatory phenotype, indicating that at least some of the 2,4-D degradative genes are on the missing fragment. The missing fragment is flanked by two identical 4.3-kb insertion sequences (IS) and shows a typical composite transposon structure of 41-kb in size, designated Tn5530. The mutant plasmid pIJB2 possesses a single copy of the IS element

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran