Expression of the arsenite oxidation regulatory operon in Rhizobium sp. str. NT-26 is under the control of two promoters that respond to different environmental cues

Rhizobium sp. str. NT-26 is a gram-negative facultative chemolithoautotrophic arsenite oxidiser that has been used as a model organism to study various aspects of arsenite oxidation including the regulation of arsenite oxidation. The three regulatory genes, aioX, aioS and aioR, are co-transcribed when NT-26 was grown in the presence or absence of arsenite. The aioXSR operon is up-regulated in stationary phase but not by the presence of arsenite in the growth medium. The two transcription start sites upstream of aioX were determined which led to the identification of two promoters, the housekeeping promoter RpoD and the growth-phase dependent promoter RpoE2. Promoter-lacZ fusions confirmed their constitutive and stationary phase expressions. The involvement of the NT-26 sigma factor RpoE2 in acting on the NT-26 RpoE2 promoter was confirmed in vivo in E. coli, which lacks a rpoE2 homologue, using a strain carrying both the promoter-lacZ fusion and the NT-26 rpoE2 gene. An in silico approach was used to search for other RpoE2 promoters and AioR-binding motifs and led to the identification of other genes that could be regulated by these proteins including those involved in quorum sensing, chemotaxis and motility expanding the signalling networks important for the microbial metabolism of arsenite

Measuring situation awareness in complex systems: Comparison of measures study

Situation Awareness (SA) is a distinct critical commodity for teams working in complex industrial systems and its measurement is a key provision in system, procedural and training design efforts. This article describes a study that was undertaken in order to compare three different SA measures (a freeze probe recall approach, a post trial subjective rating approach and a critical incident interview technique) when used to assess participant SA during a military planning task. The results indicate that only the freeze probe recall method produced a statistically significant correlation with performance on the planning task and also that there was no significant correlation between the three methods, which suggests that they were effectively measuring different things during the trials. In conclusion, the findings, whilst raising doubts over the validity of post trial subjective rating and interview-based approaches, offer validation evidence for the use of freeze probe recall approaches to measure SA. The findings are subsequently discussed with regard to their implications for the future measurement of SA in complex collaborative systems

Decay of the N=126, Fr 213 nucleus

γ rays following the EC/β+ and α decay of the N = 126, Fr213 nucleus have been observed at the CERN isotope separator on-line (ISOLDE) facility with the help of γ-ray and conversion-electron spectroscopy. These γ rays establish several hitherto unknown excited states in Rn213. Also, five new α-decay branches from the Fr213 ground state have been discovered. Shell model calculations have been performed to understand the newly observed states in Rn213. © 2016 authors. Published by the American Physical Society

Substitution of Ti3+ and Ti4+ in hibonite (CaAl12O19)

The structures of eight synthetic samples of hibonite, with variable Ti oxidation state and Ti concentration (2.4–15.9 wt% TiO2) that span the range reported for natural hibonite found in meteorites, were determined by Rietveld refinements of neutron powder diffraction data. Ti3+ was found to exclusively occupy the octahedral face-sharing M4 site irrespective of the presence or absence of Ti4+. Ti4+ partitions between the trigonal bipyramidal M2 site and the M4 site. The ratio (Ti4+ on M2):(Ti4+ on M4) appears to be constant for all the samples, with an average of 0.18(2) irrespective of the concentrations of Ti3+ and Ti4+. These substitutional sites were shown to be the most stable configurations for Ti in hibonite from calculations using density functional theory, although the predicted preference of Ti4+ for M4 over M2 is not as strong as is observed. This is attributed to the different Ti contents of the experimental and calculated structures and suggests that the Ti site occupancies might change between these concentrations. Furthermore, it is shown that Ti has a preference to occupy neighboring M4 sites such that Ti-Ti interactions occur with stabilization energies of 83 kJ/mol for Ti3+-Ti3+ and at least 15 kJ/mol for Ti4+-Ti4+. Features in optical spectroscopy and electron spin resonance data from meteoritic and synthetic hibonites that have been used to infer Ti3+/Ti4+ are shown to actually derive from these Ti-Ti interactions. The amount of Ti4+ in hibonite can be determined from the unit-cell parameters if ∑Ti is determined independently. Ti3+/Ti4+ in hibonite may record the oxygen fugacity (fO2) of the early solar nebula, however, the existence of Ti3+-Ti3+ and Ti4+-Ti4+ interactions and the potential for Ti4+-Ti3+ interactions need to be considered when interpreting spectroscopic data in terms of Ti valence state and fO2. Hibonite as a single-mineral oxybarometer must be used with caution due to the potential role of crystal chemistry (including Ti-Ti interactions) to stabilize Ti oxidation states independently of fO2

The role of primary healthcare professionals in oral cancer prevention and detection

AIM: To investigate current knowledge, examination habits and preventive practices of primary healthcare professionals in Scotland, with respect to oral cancer, and to determine any relevant training needs. SETTING: Primary care. METHOD: Questionnaires were sent to a random sample of 357 general medical practitioners (GMPs) and 331 dental practitioners throughout Scotland. Additionally, focus group research and interviews were conducted amongst primary healthcare team members. RESULTS: Whilst 58% of dental respondents reported examining regularly for signs of oral cancer, GMPs examined patients' mouths usually in response to a complaint of soreness. The majority of GMPs (85%) and dentists (63%) indicated that they felt less than confident in detecting oral cancer, with over 70% of GMPs identifying lack of training as an important barrier. Many practitioners were unclear concerning the relative importance of the presence of potentially malignant lesions in the oral cavity. A high proportion of the GMPs indicated that they should have a major role to play in oral cancer detection (66%) but many felt strongly that this should be primarily the remit of the dental team. CONCLUSION: The study revealed a need for continuing education programmes for primary care practitioners in oral cancer-related activities. This should aim to improve diagnostic skills and seek to increase practitioners' participation in preventive activities

Sensitivity of lung resistance and compliance to beta-blocker induced bronchoconstriction and long acting beta-agonist withdrawal in COPD

Little is known about impulse oscillometry (IOS) in COPD. IOS is an effort independent measure of lung resistance and reactance (compliance). We assessed how frequency dependence of resistance (R) and reactance (X) changed in response to bronchoconstriction with carvedilol followed by long acting beta-agonist (LABA) withdrawal. N = 12 patients with moderate to severe COPD were analysed, who had ≥ 100 ml fall in FEV1 with carvedilol. Compared to baseline taking ICS/LABA there were 21, 59, and 135% significant changes in resistance at 5 Hz (R5), reactance at 5 Hz (X5), and reactance area (AX), respectively, with carvedilol, while after LABA withdrawal only AX showed a further significant increase to 210% (i.e. reduced compliance). Hence changes in lung compliance rather than resistance play a more important role in the beta-2 receptor-mediated responses in COPD

Low temperature scattering with the R-matrix method: the Morse potential

Experiments are starting to probe collisions and chemical reactions between atoms and molecules at ultra-low temperatures. We have developed a new theoretical procedure for studying these collisions using the R-matrix method. Here this method is tested for the atom -- atom collisions described by a Morse potential. Analytic solutions for continuum states of the Morse potential are derived and compared with numerical results computed using an R-matrix method where the inner region wavefunctions are obtained using a standard nuclear motion algorithm. Results are given for eigenphases and scattering lengths. Excellent agreement is obtained in all cases. Progress in developing a general procedure for treating ultra-low energy reactive and non-reactive collisions is discussed.Comment: 18 pages, 6 figures, 3 tables, conferenc

Prevalence of Malaria and Anaemia among HIV Infected Pregnant women Receiving Co-trimoxazole Prophylaxis in Tanzania: A Cross Sectional Study in Kinondoni Municipality.

HIV-infected pregnant women are particularly more susceptible to the deleterious effects of malaria infection particularly anaemia. In order to prevent opportunistic infections and malaria, a policy of daily co-trimoxazole prophylaxis without the standard Suphadoxine-Pyrimethamine intermittent preventive treatment (SP-IPT) was introduced to all HIV infected pregnant women in the year 2011. However, there is limited information about the effectiveness of this policy. This was a cross sectional study conducted among HIV-infected pregnant women receiving co-trimoxazole prophylaxis in eight public health facilities in Kinondoni Municipality from February to April 2013. Blood was tested for malaria infection and anaemia (haemoglobin <11 g/dl). Data were collected on the adherence to co-trimoxazole prophylaxis and other risk factors for malaria infection and anaemia. Pearson chi-square test, Fischer's exact test and multivariate logistic regression were used in the statistical analysis. This study enrolled 420 HIV infected pregnant women. The prevalence of malaria infection was 4.5%, while that of anaemia was 54%. The proportion of subjects with poor adherence to co-trimoxazole was 50.5%. As compared to HIV infected pregnant women with good adherence to co-trimoxazole prophylaxis, the poor adherents were more likely to have a malaria infection (Adjusted Odds Ratio, AOR = 6.81, 95%CI = 1.35-34.43, P = 0.02) or anaemia (AOR = 1.75, 95%CI = 1.03-2.98, P = 0.039). Other risk factors associated with anaemia were advanced WHO clinical stages, current malaria infection and history of episodes of malaria illness during the index pregnancy. The prevalence of malaria was low; however, a significant proportion of subjects had anaemia. Good adherence to co-trimoxazole prophylaxis was associated with reduction of both malaria infection and anaemia among HIV infected pregnant women

Improving the delivery of care for patients with diabetes through understanding optimised team work and organisation in primary care

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