896 research outputs found

    Chemical hazards database and detection system for Microgravity and Materials Processing Facility (MMPF)

    Get PDF
    The ability to identify contaminants associated with experiments and facilities is directly related to the safety of the Space Station. A means of identifying these contaminants has been developed through this contracting effort. The delivered system provides a listing of the materials and/or chemicals associated with each facility, information as to the contaminant's physical state, a list of the quantity and/or volume of each suspected contaminant, a database of the toxicological hazards associated with each contaminant, a recommended means of rapid identification of the contaminants under operational conditions, a method of identifying possible failure modes and effects analysis associated with each facility, and a fault tree-type analysis that will provide a means of identifying potential hazardous conditions related to future planned missions

    Transcriptome Analysis of \u3ci\u3eBifidobacterium Longum\u3c/i\u3e Strains that Show a Differential Response to Hydrogen Peroxide Stress

    Get PDF
    Consumer and commercial interest in foods containing probiotic bifidobacteria is increasing. However, because bifidobacteria are anaerobic, oxidative stress can diminish cell viability during production and storage of bioactive foods. We previously found Bifidobacterium longum strain NCC2705 had signifi- cantly greater intrinsic and inducible resistance to hydrogen peroxide (H2O2) than strain D2957. Here, we explored the basis for these differences by examining the transcriptional responses of both strains to sub-lethal H2O2 exposure for 5- or 60-min. Strain NCC2705 had 288 genes that were differentially expressed after the 5-min treatment and 114 differentially expressed genes after the 60-min treatment. In contrast, strain D2957 had only 21 and 90 differentially expressed genes after the 5- and 60-min treatments, respectively. Both strains showed up-regulation of genes coding enzymes implicated in oxidative stress resistance, such as thioredoxin, thioredoxin reductase, peroxiredoxin, ferredoxin, glutaredoxin, and anaerobic ribonucleotide reductase, but induction levels were typically highest in NCC2705. Compared to D2957, NCC2705 also had more up-regulated genes involved in transcriptional regulation and more down-regulated genes involved in sugar transport and metabolism. These results provide a greater understanding of the molecular basis for oxidative stress resistance in B. longum and the factors that contribute to strain-to-strain variability in survival in bioactive food products

    Genetic and Physiological Responses of \u3ci\u3eBifidobacterium animalis\u3c/i\u3e subsp. \u3ci\u3elactis\u3c/i\u3e to Hydrogen Peroxide Stress

    Get PDF
    Consumer interest in probiotic bifidobacteria is increasing, but industry efforts to secure high cell viability in foods is determined by these anaerobes’ sensitivity to oxidative stress. To address this limitation, we investigated genetic and physiological responses of two fully sequenced Bifidobacterium animalis subsp. lactis strains, BL-04 and DSM 10140, to hydrogen peroxide (H2O2) stress. Although the genome sequences for these strains are highly clonal, prior work showed they differ in both intrinsic and inducible H2O2 resistance. Transcriptome analysis of early stationary phase cells exposed to a sub-lethal H2O2 concentration detected significant (P2O2 stress resistance might be due to a mutation in a BL-04 gene encoding long chain fatty acid-coA ligase. To explore this possibility, membrane fatty acids were isolated and analyzed by GC-MS. Results confirmed the strains had significantly different lipid profiles; the BL-04 membrane contained higher percentages of C14:0 and C16:0, and lower percentages of C16:1n7 and C18:1n9. Alteration of the DSM 10140 membrane lipid composition using modified growth medium to more closely mimic that of BL-04 yielded cells that showed increased intrinsic resistance to lethal H2O2 challenge, but did not display an inducible H2O2 stress response. Results show deliberate stress induction or membrane lipid modification can be employed to significantly improve H2O2 resistance in B. animalis subsp. lactis strains

    Colorectal Cancer Screening and Perceived Disgust:The Importance of the Ick Factor in Faecal Occult Blood Test Uptake

    Get PDF
    Background: Colorectal cancer is a major cause of cancer deaths worldwide. Screening is key to early detection but uptake of national programmes is poor, especially amongst those from lower socio-economic backgrounds. Decisions not to take up screening may be based more on emotional rather than rational evaluations. We aimed to examine the importance of perceived disgust (the ‘ICK’ factor) in determining colorectal cancer screening uptake, in a large, randomised controlled trial. Methods: This paper reports secondary analysis of a randomised controlled trial of a simple, questionnaire-based Anticipated Regret (AR) intervention, which was delivered alongside existing pre-notification letters. 60,000 adults aged 50- 74 who were participant in the Scottish National Screening programme were randomised to one of 3 treatment arms: 1) no questionnaire (control), 2) Health Locus of Control (HLOC) questionnaire or 3) AR questionnaire. Primary outcome was Faecal Occult Blood Test kit return (FOBT uptake). 13,645 people completed questionnaires of secondary outcomes including intention to return test kit and a new self-report measure of perceived disgust (ICK-C). Results: Intentions, ICK and AR were all predictors of FOBT uptake; however, for people who expressed strong intentions to return their FOBT kit, only ICK differentiated kit returners from non-returners, with non-returners reporting higher disgust (mean difference=0.51; 95% CI for difference (0.37, 0.64), Cohen’s d=0.34). The 4-item ICK-C showed excellent internal reliability and predictive validity with regard to an objective measure i.e., FOBT uptake. Conclusions: The findings show that perceived disgust is an important emotional psychological construct in determining uptake of colorectal cancer screening. We also demonstrated that a simple 4-item scale (the ‘ICK-C), developed to be used in research on colorectal cancer screening, has excellent psychometric properties

    Microbial Challenge Testing of Single Liquid Cathode Feed Water Electrolysis Cells for the International Space Station (ISS) Oxygen Generator Assembly (OGA)

    Get PDF
    The International Space Station (ISS) Oxygen Generator Assembly (OGA) operational performance may be adversely impacted by microbiological growth and biofilm formation over the electrolysis cell membranes. Biofilms could hinder the transport of water from the bulk fluid stream to the membranes and increase the cell concentration overpotential resulting in higher cell voltages and a shorter cell life. A microbial challenge test was performed on duplicate single liquid-cathode feed water electrolysis cells to evaluate operational performance with increasing levels of a mixture of five bacteria isolated from ISS and Space Shuttle potable water systems. Baseline performance of the single water electrolysis cells was determined for approximately one month with deionized water. Monthly performance was also determined following each inoculation of the feed tank with 100, 1000, 10,000 and 100,000 cells/ml of the mixed suspension of test bacteria. Water samples from the feed tank and recirculating water loops for each cell were periodically analyzed for enumeration and speciation of bacteria and total organic carbon. While initially a concern, this test program has demonstrated that the performance of the electrolysis cell is not adversely impacted by feed water containing the five species of bacteria tested at a concentration measured as high as 1,000,000 colony forming units (CFU)/ml. This paper presents the methodologies used in the conduct of this test program along with the performance test results at each level of bacteria concentration

    DEMAND BASED RELIABILITY:APROPOSED MEASUREMENTAPPROACH

    Get PDF
    ABSTRACT: Significant change is taking place in the power generation market. We are witnessing structural change as we move to a deregulated and competitive global market. And we can also see significant technological change, as new products are driven towards improved efficiencies, greater output and environmental friendliness. Measuring the impact of these changes in terms of efficiency, output and reduced emissions is a straightforward exercise, and the ability to judge if the change has been positive is relatively objective. However, these structural and technological changes have created challenges in terms of reliability and availability measurements. • First, our measurement approach is obsolete and has no consideration for duty cycle... The demand, the mission profile, which must be achieved for the unit to meet its economic contribution value, is the single most important issue for power producers today • Second, if the measurements have no consideration for the demand that the unit must meet, then the measure is not tied to the profitability of the plant, and therefore the operators are forced to use non-standard measures to accommodate management reporting. • And third, the strong relationship between effective plant operations and profitability demands "real time" data gathering from the unit control or plant DCS, and transformation of the data points into meaningful information for effective decision support, specifically related to the availability and reliability o f systems, components, and the full plant, with a specific focus on measuring "demand" based availability and reliability. This paper addresses the issue and the opportunities associated with developing both new standard for measuring demand related reliability and availability, as well as the focus on "real time" data capture

    The impact of personalised risk information compared to a positive/negative result on informed choice and intention to undergo colonoscopy following colorectal Cancer screening in Scotland (PERICCS) - a randomised controlled trial:study protocol

    Get PDF
    Background In Scotland a new, easier to complete bowel screening test, the Faecal Immunochemical Test (FIT), has been introduced. This test gives more accurate information about an individual’s risk of having colorectal cancer (CRC), based on their age and gender, and could lead to fewer missed cancers compared to the current screening test. However, there is no evidence of the effect on colonoscopy uptake of providing individuals with personalised risk information following a positive FIT test. The objectives of the study are: 1) To develop novel methods of presenting personalised risk information in an easy-to-understand format using infographics with involvement of members of the public 2) To assess the impact of different presentations of risk information on informed choice and intention to take up an offer of colonoscopy after FIT 3) To assess participants’ responses to receiving personal risk information (knowledge, attitudes to screening/risk, emotional responses including anxiety). Methods Adults (age range 50–74) registered on the Scottish Bowel Screening database will be invited by letter to take part. Consenting participants will be randomised to one of three groups to receive hypothetical information about their risk of cancer, based on age, gender and faecal haemoglobin concentration: 1) personalised risk information in numeric form (e.g. 1 in 100) with use of infographics, 2) personalised information described as ‘highest’, ‘moderate’ or ‘lowest’ risk with use of infographics, and 3) as a ‘positive’ test result, as is current practice. Groups will be compared on informed choice, intention to have a colonoscopy, and satisfaction with their decision. Follow-up semi-structured qualitative interviews will be conducted, by telephone, with a small number of consenting participants (n = 10 per group) to explore the acceptability/readability and any potential negative impact of the risk information, participants’ understanding of risk factors, attitudes to the different scenarios, and reasons for reported intentions. Discussion Proving personalised risk information and allowing patient choice could lead to improved detection of CRC and increase patient satisfaction by facilitating informed choice over when/whether to undergo further invasive screening. However, we need to determine whether/how informed choice can be achieved and assess the potential impact on the colonoscopy service

    The impact of hypothetical PErsonalised Risk Information on informed choice and intention to undergo Colorectal Cancer screening colonoscopy in Scotland (PERICCS)—a randomised controlled trial

    Get PDF
    Background There is currently no existing evidence on the effects of personalised risk information on uptake of colonoscopy following first line screening for colorectal cancer. This study aimed to measure the impact of providing risk information based on faecal haemoglobin concentration to allow a fully informed choice around whether or not to undergo colonoscopy. Methods Two thousand seven hundred sixty-seven participants from the Scottish Bowel Screening Programme (SBoSP) database, who had not recently been invited for screening, were randomised to receive one of three types of hypothetical risk information materials: (1) numerical risk information (risk categories of one in 40, one in 1600 and one in 3500), (2) categorical risk information (highest, moderate and lowest risk), or (3) positive screening result letter (control group). The primary outcome was the impact of the risk materials on intention to undergo colonoscopy, to allow comparison with the current colonoscopy uptake of 77% for those with a positive screening result in the SBoSP. Secondary outcomes were knowledge, attitudes and emotional responses to the materials. Results Four hundred thirty-four (15.7%) agreed to participate with 100 from the numerical risk group (69.0%), 104 from the categorical risk group (72.2%) and 104 from the control group (71.7%) returning completed materials. Intention to undergo colonoscopy was highest in the highest risk groups for the numerical and categorical study arms (96.8% and 95.3%, respectively), but even in the lowest risk groups was > 50% (58.1% and 60.7%, respectively). Adequate knowledge of colorectal screening and the risks and benefits of colonoscopy was found in ≥ 98% of participants in all three arms. All participants reported that they found the information easy-to-understand. 19.1%, 24.0% and 29.6% of those in the numerical, categorical and control group, respectively, reported that they found the information distressing (p > 0.05). Conclusions Applying the risk categories to existing SBoSP data shows that if all participants were offered an informed choice to have colonoscopy, over two thirds of participants would intend to have the test. Equating to an increase in the number of screening colonoscopies from approx. 14,000 to 400,000 per annum, this would place an unmanageable demand on colonoscopy services, with a very small proportion of cancers and pre-cancers detected. However, the response to the materials were very positive, suggesting that providing risk information to those in lowest and moderate risk groups along with advice that colonoscopy is not currently recommended may be an option. Future research would be required to examine actual uptake
    • …
    corecore