Plant host and sugar alcohol induced exopolysaccharide biosynthesis in the Burkholderia cepacia complex.

© Society for General Microbiology, 2008. This is an author manuscript that has been accepted for publication in Microbiology, copyright Society for General Microbiology, but has not been copy-edited, formatted or proofed. Cite this article as appearing in Microbiology. This version of the manuscript may not be duplicated or reproduced, other than for personal use or within the rule of 'Fair Use of Copyrighted Materials' (section 17, Title 17, US Code), without permission from the copyright owner, Society for General Microbiology. The Society for General Microbiology disclaims any responsibility or liability for errors or omissions in this version of the manuscript or in any version derived from it by any other parties. The final copy-edited, published article, which is the version of record, can be found at http://mic.sgmjournals.org, and is freely available without a subscription 12 months after publication.The species that presently constitute the Burkholderia cepacia complex (Bcc) have multiple roles; they include soil and water saprophytes, bioremediators, and plant, animal and human pathogens. Since the first description of pathogenicity in the Bcc was based on sour skin rot of onion bulbs, this study returned to this plant host to investigate the onion-associated phenotype of the Bcc. Many Bcc isolates, which were previously considered to be non-mucoid, produced copious amounts of exopolysaccharide (EPS) when onion tissue was provided as the sole nutrient. EPS production was not species-specific, was observed in isolates from both clinical and environmental sources, and did not correlate with the ability to cause maceration of onion tissue. Chemical analysis suggested that the onion components responsible for EPS induction were primarily the carbohydrates sucrose, fructose and fructans. Additional sugars were investigated, and all alcohol sugars tested were able to induce EPS production, in particular mannitol and glucitol. To investigate the molecular basis for EPS biosynthesis, we focused on the highly conserved bce gene cluster thought to be involved in cepacian biosynthesis. We demonstrated induction of the bce gene cluster by mannitol, and found a clear correlation between the inability of representatives of the Burkholderia cenocepacia ET12 lineage to produce EPS and the presence of an 11 bp deletion within the bceB gene, which encodes a glycosyltransferase. Insertional inactivation of bceB in Burkholderia ambifaria AMMD results in loss of EPS production on sugar alcohol media. These novel and surprising insights into EPS biosynthesis highlight the metabolic potential of the Bcc and show that a potential virulence factor may not be detected by routine laboratory culture. Our results also highlight a potential hazard in the use of inhaled mannitol as an osmolyte to improve mucociliary clearance in individuals with cystic fibrosis

Ambient greenness, access to local green spaces, and subsequent mental health: a 10-year longitudinal dynamic panel study of 2·3 million adults in Wales

Background: Evidence suggests living in greener areas, or close to green blue spaces (GBS; parks, lakes, or beaches) benefits mental health, but longitudinal evidence when GBS exposures precede outcomes is limited. We aimed to analyse the impact of living in greener areas, or close to GBS over time on subsequent adult mental health, explicitly considering health inequalities, and disentangling the mental health benefits of potentially accessing GBS from living in greener areas.Methods; A cohort of the adults in Wales, UK (>16 years; n=2,341,591) was constructed from electronic health record (EHR) data sources, 2008-2019, comprising 19,141,896 person-years of follow-up. Household ambient greenness (Enhanced Vegetation Index, EVI), access to GBS (counts, distance to nearest); and common mental health disorders (CMD, based on a validated algorithm combining current diagnoses or symptoms of anxiety or depression (treated or untreated in the preceding one-year period), or treatment of historical diagnosis(es) frombefore the ‘current’ cohort (up to 8 years prior, to 2000), where diagnosis preceded treatment) were record-linked. Cumulative exposure values were created for each adult, censoring for CMD, migration out-of-Wales, death, or end of cohort. Exposure and CMD associations were evaluated using multivariate logistic regression, stratified by area-level deprivation.Findings: After adjustment, exposure to greater ambient greenness over time (+0.1 increased EVI on a 0-1 scale) was associated with lower odds of subsequent CMD (Adjusted Odds Ratio (AOR) = 0.80, 95% CI: 0.80, 0.81), where CMD was based on a combination of current diagnoses or symptoms (treated or untreated in the preceding one-year period), or treatments). Ten percentile points more access to GBS was associated with lower odds of a later CMD (AOR = 0.93 95% CI 0.93, 0.93). Every additional 360m to the nearest GBS was associated with higher odds of CMD (AOR = 1.05, 95% CI 1.04, 1.05). We found differences across deprivation quintiles. Interpretation Ambient exposure is associated with the greatest reduced risk of CMD, particularly for adults who live in deprived communities. Findings support authorities responsible for GBS who are attempting to engage planners and policy makers, to ensure GBS meets resident needs

Large-scale structure, the cosmic microwave background, and primordial non-gaussianity

Since cosmic-microwave-background (CMB) and large-scale-structure (LSS) data will shortly improve dramatically with the Microwave Anisotropy Probe (MAP) and Planck Surveyor, and the Anglo-Australian 2-Degree Field (2dF) and Sloan Digital Sky Survey (SDSS), respectively, it is timely to ask which of the CMB or LSS will provide a better probe of primordial non-gaussianity. In this paper we consider this question, using the bispectrum as a discriminating statistic. We consider several non-gaussian models and find that in each case the CMB will provide a better probe of primordial non-gaussianity. Since the bispectrum is the lowest-order statistic expected to arise in a generic non-gaussian model, our results suggest that if CMB maps appear gaussian, then apparent deviations from gaussian initial conditions in galaxy surveys can be attributed with confidence to the effects of biasing. We demonstrate this precisely for the spatial bispectrum induced by local non-linear biasing.Comment: 6 pages, 2 figures, submitted as a letter to MNRA

Visiting nature is associated with lower socioeconomic inequalities in well-being in Wales

Natural environments can promote well-being through multiple mechanisms. Many studies have investigated relationships between residential green/blue space (GBS) and well-being, fewer explore relationships with actual use of GBS. We used a nationally representative survey, the National Survey for Wales, anonymously linked with spatial GBS data to investigate associations of well-being with both residential GBS and time in nature (N = 7631). Both residential GBS and time spent in nature were associated with subjective well-being. Higher green-ness was associated with lower well-being, counter to hypotheses (predicting the Warwick and Edinburgh Mental Well-Being Scale (WEMWBS): Enhanced vegetation index β =  − 1.84, 95% confidence interval (CI) − 3.63, − 0.05) but time spent in nature was associated with higher well-being (four hours a week in nature vs. none β = 3.57, 95% CI 3.02, 4.13). There was no clear association between nearest GBS proximity and well-being. In support of the equigenesis theory, time spent in nature was associated with smaller socioeconomic inequalities in well-being. The difference in WEMWBS (possible range 14–70) between those who did and did not live in material deprivation was 7.7 points for those spending no time in nature, and less at 4.5 points for those spending time in nature up to 1 h per week. Facilitating access and making it easier for people to spend time in nature may be one way to reduce socioeconomic inequalities in well-being

The Phase-Contrast Imaging Instrument at the Matter in Extreme Conditions Endstation at LCLS

We describe the Phase-Contrast Imaging instrument at the Matter in Extreme Conditions (MEC) endstation of the Linac Coherent Light Source. The instrument can image phenomena with a spatial resolution of a few hundreds of nanometers and at the same time reveal the atomic structure through X-ray diffraction, with a temporal resolution better than 100 femtosecond. It was specifically designed for studies relevant to High-Energy-Density Science and can monitor, e.g., shock fronts, phase transitions, or void collapses. This versatile instrument was commissioned last year and is now available to the MEC user community

Intensity of COVID-19 in care homes following Hospital Discharge in the early stages of the UK epidemic

BackgroundA defining feature of the COVID-19 pandemic in many countries was the tragic extent to which care home residents were affected, and the difficulty preventing introduction and subsequent spread of infection. Management of risk in care homes requires good evidence on the most important transmission pathways. One hypothesised route at the start of the pandemic, prior to widespread testing, was transfer of patients from hospitals, which were experiencing high levels of nosocomial events.MethodsWe tested the hypothesis that hospital discharge events increased the intensity of care home cases using a national individually linked health record cohort in Wales, UK. We monitored 186,772 hospital discharge events over the period March to July 2020, tracking individuals to 923 care homes and recording the daily case rate in the homes populated by 15,772 residents. We estimated the risk of an increase in cases rates following exposure to a hospital discharge using multi-level hierarchical logistic regression, and a novel stochastic Hawkes process outbreak model.FindingsIn regression analysis, after adjusting for care home size, we found no significant association between hospital discharge and subsequent increases in care home case numbers (odds ratio: 0.99, 95% CI 0.82, 1.90). Risk factors for increased cases included care home size, care home resident density, and provision of nursing care. Using our outbreak model, we found a significant effect of hospital discharge on the subsequent intensity of cases. However, the effect was small, and considerably less than the effect of care home size, suggesting the highest risk of introduction came from interaction with the community. We estimated approximately 1.8% of hospital discharged patients may have been infected.InterpretationThere is growing evidence in the UK that the risk of transfer of COVID-19 from the high-risk hospital setting to the high-risk care home setting during the early stages of the pandemic was relatively small. Although access to testing was limited to initial symptomatic cases in each care home at this time, our results suggest that reduced numbers of discharges, selection of patients, and action taken within care homes following transfer all may have contributed to mitigation. The precise key transmission routes from the community remain to be quantified

Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

Reaction Engineering International (REI) managed a team of experts from University of Utah, Siemens Energy, Praxair, Vattenfall AB, Sandia National Laboratories, Brigham Young University (BYU) and Corrosion Management Ltd. to perform multi-scale experiments, coupled with mechanism development, process modeling and CFD modeling, for both applied and fundamental investigations. The primary objective of this program was to acquire data and develop tools to characterize and predict impacts of CO{sub 2} flue gas recycle and burner feed design on flame characteristics (burnout, NO{sub x}, SO{sub x}, mercury and fine particle emissions, heat transfer) and operational concerns (fouling, slagging and corrosion) inherent in the retrofit of existing coal-fired boilers for oxy-coal combustion. Experimental work was conducted at Sandia National Laboratories’ Entrained Flow Reactor, the University of Utah Industrial Combustion Research Facility, and Brigham Young University. Process modeling and computational fluid dynamics (CFD) modeling was performed at REI. Successful completion of the project objectives resulted in the following key deliverables: 1) Multi-scale test data from 0.1 kW bench-scale, 100 kW and 200 kW laboratory-scale, and 1 MW semi-industrial scale combustors that describe differences in flame characteristics, fouling, slagging and corrosion for coal combustion under air-firing and oxygen-firing conditions, including sensitivity to oxy-burner design and flue gas recycle composition. 2) Validated mechanisms developed from test data that describe fouling, slagging, waterwall corrosion, heat transfer, char burnout and sooting under coal oxy-combustion conditions. The mechanisms were presented in a form suitable for inclusion in CFD models or process models. 3) Principles to guide design of pilot-scale and full-scale coal oxy-firing systems and flue gas recycle configurations, such that boiler operational impacts from oxy-combustion retrofits are minimized. 4) Assessment of oxy-combustion impacts in two full-scale coal-fired utility boiler retrofits based on computational fluid dynamics (CFD) modeling of air-fired and oxygen-fired operation. This research determined that it is technically feasible to retrofit the combustion system in an air-fired boiler for oxy-fired operation. The impacts of CO{sub 2} flue gas recycle and burner design on flame characteristics (burnout, NO{sub x}, SO{sub x}, mercury and fine particle emissions, heat transfer) and operational concerns (fouling, slagging and corrosion) were minimal, with the exception of high sulfur levels resulting from untreated flue gas recycle with medium and high-sulfur coals. This work focused on combustion in the radiant and convective sections of the boiler and did not address boiler system integration issues, plant efficiencies, impacts on downstream air pollution control devices, or CO{sub 2} capture and compression. The experimental data, oxy-firing system principles and oxy-combustion process mechanisms provided by this work can be used by electric utilities, boiler OEMs, equipment suppliers, design firms, software vendors, consultants and government agencies to assess retrofit applications of oxy-combustion technologies to existing boilers and to guide development of new designs