289 research outputs found

    Who are the cable bacteria

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    In 2010, a completely novel type of microbial metabolism was discovered in marine sediments, which induces the transport of electrons over centimetre scales. The actors behind this process are the “cable bacteria”: long (> 2cm), filamentous, multicellular(>104 cells) bacteria. Cable bacteria use the electron transport to couple redox reactions between their two key metabolic resources. The bottom cells of a cable bacteria filament oxidize sulfide, which is abundant in the deeper anoxic zone of the marine sediment. The electrons derived from the sulfide oxidation are then transported along the cells of the cable bacteria to finally arrive at the cells in the oxic part of the sediment. Here these electrons are used in the second part of the cable bacteria metabolism, the reduction of oxygen. By establishing electrical currents, the cable bacteria turn the seafloor into an “electrical ecosystem”

    Analysis of a hyperbolic paraboloidal shell

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    Call number: LD2668 .R4 1963 B9

    Who are the cable bacteria?

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    Associations between Objectively-measured Acoustic Parameters and Occupational Voice Use among Primary School Teachers☆

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    Abstract Previous studies on voice disorders among teachers have reported that this multidimensional phenomenon is associated with individual factors, external factors related with the audience and with the type of task and the occupation. This work deals with the long-term monitoring (1 to 4 days) of 31 primary school teachers and with the determination of the relationship between conversational and occupational voice parameters. Statistical analysis was performed to investigate the relationships between voice parameters and room acoustics-related factors

    Long-distance electron transport occurs globally in marine sediments

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    Recently, long filamentous bacteria have been reported conducting electrons over centimetre distances in marine sediments. These so-called cable bacteria perform an electrogenic form of sulfur oxidation, whereby long-distance electron transport links sulfide oxidation in deeper sediment horizons to oxygen reduction in the upper millimetres of the sediment. Electrogenic sulfur oxidation exerts a strong impact on the local sediment biogeochemistry, but it is currently unknown how prevalent the process is within the seafloor. Here we provide a state-of-the-art assessment of its global distribution by combining new field observations with previous reports from the literature. This synthesis demonstrates that electrogenic sulfur oxidation, and hence microbial long-distance electron transport, is a widespread phenomenon in the present-day seafloor. The process is found in coastal sediments within different climate zones (off the Netherlands, Greenland, the USA, Australia) and thrives on a range of different coastal habitats (estuaries, salt marshes, mangroves, coastal hypoxic basins, intertidal flats). The combination of a widespread occurrence and a strong local geochemical imprint suggests that electrogenic sulfur oxidation could be an important, and hitherto overlooked, component of the marine cycle of carbon, sulfur and other elements

    Методы минимизации энергопотребления при проектировании КМОП БИС

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    Представлены основные методы, позволяющие уменьшить величину рассеиваемой мощности на этапах проектирования КМОП БИС. Приведена классификация источников рассеиваемой мощности

    Does reduced employment protection increase the employment disadvantage of workers with low education and poorer health?

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    Background Declines in employment protection may have disproportionate effects on employment opportunities of workers with low education and poorer health. This study investigates the impact of changes in employment protection levels on employment rates according to education and health in 23 European countries. Methods Data were taken from the 4-year rotating panel European Union Statistics on Income and Living Conditions study. Employed participants aged 29-59 years (n = 334 999) were followed for 1 year over an 11-year period, from 2003 up to 2014. A logistic regression model with country and period fixed effects was used to estimate the association between changes in the Organisation for Economic Co-operation and Development (OECD) employment protection index and labour market outcomes, incorporating interaction terms with education and health. Results 15 of the 23 countries saw their level of employment protection decline between 2003 and 2014. Reduced employment protection of temporary workers increased odds of early retirement (OR 6.29, 95% CI 3.17 to 12.48) and unemployment (OR 1.37, 95% CI 1.07 to 1.76). Reduced employment protection of permanent workers increased odds of early retirement more among workers in poor health (OR 4.46, 95% CI 2.26 to 8.78) than among workers in good health (OR 2.58, 95% CI 1.30 to 5.10). The impact of reduced employment protection of temporary workers on unemployment was stronger among lower-educated workers (OR 1.47, 95% CI 1.13 to 1.90) than among higher-educated workers (OR 1.21, 95% CI 0.95 to 1.54). Conclusion Reduced employment protection increased the odds of early exit from paid employment, especially among workers with lower education and poorer health. Employment protection laws may help reduce the employment disadvantage of workers with low education and poorer health

    Influence of changing working conditions on exit from paid employment among workers with a chronic disease

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    Objectives To investigate the relation between changes in working conditions and exit from paid employment among workers with a chronic disease. Methods Six waves from the longitudinal Study on Transitions in Employment, Ability and Motivation (2010–2016), enriched with tax-based employment information from Statistics Netherlands (2011–2017), were available for 4820 chronically ill workers aged 45–63 years (mean 55.3 years, SD 5.1). A change in working conditions (physical workload, psychological job demands, job autonomy, emotional job demands and social support) was defined as an increase or decrease between two consecutive waves of at least one SD. Discrete-time survival models with repeated measurements were used to estimate the relative risk (RR) of a change in working conditions on exiting paid employment in the following year compared with no change and consecutive favourable working conditions. Results A favourable change in physical workload lowered the risk to exit paid employment (RR 0.46, 95% CI 0.22 to 0.94). An adverse change in psychosocial working conditions, especially a decrease in social support (RR 2.07, 95% CI 1.52 to 2.81), increased the likelihood to exit paid employment. In contrast, a favourable change in psychological job demands increased the risk to exit paid employment (RR 1.57, 95% CI 1.09 to 2.24). Multiple adverse changes increased the risk to exit paid employment up to six times (RR 6.06, 95% CI 2.83 to 12.98). Conclusions Changes in working conditions among workers with chronic diseases influence exit from paid employment. Ensuring that working conditions can be adapted to the needs of workers with a chronic disease may help to extend working life

    The influence of unhealthy behaviours on early exit from paid employment among workers with a chronic disease:a prospective study using the Lifelines cohort

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    OBJECTIVES: This study examined the risk of unhealthy behaviours and the additive effects of multiple unhealthy behaviours on exit from paid employment among workers with a chronic disease and investigated effect modification by gender and educational level. METHODS: Data from the Lifelines cohort, collected between 2006 and 2013, were enriched with registry data from Statistics Netherlands with up to 11 years follow-up. Workers with a chronic disease were selected (n=11,467). The influence of unhealthy behaviours (physical inactivity, smoking, unhealthy diet, high alcohol intake, and obesity) on exit from paid employment (unemployment, disability benefits, early retirement, and economic inactivity) was examined using competing risk models. To examine effect modification by gender and educational level, interaction terms were added. RESULTS: Smoking and low fruit intake increased the risk to exit paid employment through unemployment and disability benefits. Low vegetable intake increased the risk of unemployment, obesity the risk of receiving disability benefits, and high alcohol intake the risk of early retirement. Physical inactivity was not associated with any exit from paid employment. Having multiple unhealthy behaviours increased the risk of both unemployment and of receiving disability. No consistent effect modification for gender or educational level was found. CONCLUSIONS: Unhealthy behaviours increased the risk to exit paid employment through unemployment and disability benefits among workers with a chronic disease, and this risk increased when having multiple unhealthy behaviours. Health promotion to support workers with chronic diseases to make healthier choices may help to extend their working life
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