13,537 research outputs found

    Passive CO<sub>2</sub> removal in urban soils:evidence from brownfield sites

    Get PDF
    Management of urban brownfield land can contribute to significant removal of atmospheric CO2 through the development of soil carbonate minerals. However, the potential magnitude and stability of this carbon sink is poorly quantified as previous studies address a limited range of conditions and short durations. Furthermore, the suitability of carbonate-sequestering soils for construction has not been investigated. To address these issues we measured total inorganic carbon, permeability and ground strength in the top 20 cm of soil at 20 brownfield sites in northern England, between 2015 and 2017. Across all sites accumulation occurred at a rate of 1–16 t C ha−1 yr−1, as calcite (CaCO3), corresponding to removal of approximately 4–59 t CO2 ha−1 yr−1, with the highest rate in the first 15 years after demolition. C and O stable isotope analysis of calcite confirms the atmospheric origin of the measured inorganic carbon. Statistical modelling found that pH and the content of fine materials (combined silt and clay content) were the best predictors of the total inorganic carbon content of the samples. Measurement of permeability shows that sites with carbonated soils possess a similar risk of run-off or flooding to sandy soils. Soil strength, measured as in-situ bearing capacity, increased with carbonation. These results demonstrate that the management of urban brownfield land to retain fine material derived from concrete crushing on site following demolition will promote calcite precipitation in soils, and so offers an additional CO2 removal mechanism, with no detrimental effect on drainage and possible improvements in strength. Given the large area of brownfield land that is available for development, the contribution of this process to CO2 removal by urban soils needs to be recognised in CO2 mitigation policies

    Increased human pathogenic potential of Escherichia coli from polymicrobial urinary tract infections in comparison to isolates from monomicrobial culture samples

    Get PDF
    The current diagnostic standard procedure outlined by the Health Protection Agency for urinary tract infections (UTIs) in clinical laboratories does not report bacteria isolated from samples containing three or more different bacterial species. As a result many UTIs go unreported and untreated, particularly in elderly patients, where polymicrobial UTI samples are especially prevalent. This study reports the presence of the major uropathogenic species in mixed culture urine samples from elderly patients, and of resistance to front-line antibiotics, with potentially increased levels of resistance to ciprofloxacin and trimethoprim. Most importantly, the study highlights that Escherichia coli present in polymicrobial UTI samples are statistically more invasive (P<0.001) in in vitro epithelial cell infection assays than those isolated from monomicrobial culture samples. In summary, the results of this study suggest that the current diagnostic standard procedure for polymicrobial UTI samples needs to be reassessed, and that E. coli present in polymicrobial UTI samples may pose an increased risk to human health

    An exploration of predictors of children's nurses' attitudes, knowledge, confidence and clinical behavioural intentions towards children and young people who self-harm

    Get PDF
    Aims and objectives: To explore the potential predictors of children's nurses? attitudes, knowledge and confidence towards caring for children and young people admitted to hospital with self-harm. Background Admissions to paediatric inpatient settings for individuals who have self-harmed are growing. Limited previous research suggests that nurses have mixed attitudes towards people who have self-harmed and potentially lack the confidence to provide effective care. There is a specific paucity of research in this area for children's nurses. Design: A cross-sectional descriptive survey was used to gather data for exploration of variables associated with attitudes, confidence, knowledge and clinical behavioural intentions of 98 registered children's nurses in a single tertiary children's hospital, colocated in a large acute NHS Trust in the UK. Methods: Data were collected over a 4 weeks in 2015, using an online survey tool. The predictive effect of several demographic variables was tested on the outcomes of attitudes, knowledge, confidence and behavioural intentions, which were collected using relevant, previously used outcome measures. Results: Increased experience was found to be associated with improved attitudes relating to negativity. Previous training in caring for children who had self-harmed was found to be associated with improved attitudes around perceived effectiveness of their care. Higher academic qualifications and having undertaken previous training on self-harm were each found to be associated with increased knowledge of self-harm, and increased age was associated with reduced knowledge of self-harm. Conclusions: This study provides an initial exploration of variables associated with attitudes, knowledge, confidence and behaviour intentions of registered children's nurses in relation to caring for CYP who have self-harmed. Relevance to clinical practice: Targeted training on caring for CYP who have self-harmed should be considered as a component of continuing education for registered children's nurses in the UK to improve the experience and outcomes for this patient group

    A taxonomic review of Cephalaria (Dipsacaceae) in the Cape Floristic Region

    Get PDF
    AbstractSix species of Cephalaria are recorded from the Cape Floristic Region (CFR), with four rare and localised species endemic to the region in the extreme southwest, and two species widely distributed in the east of the country and just entering the CFR region in the extreme east. We review these species, with full descriptions, illustrations and notes on distribution, ecology, and conservation status

    Bounds on the diameter of Cayley graphs of the symmetric group

    Get PDF
    In this paper we are concerned with the conjecture that, for any set of generators S of the symmetric group of degree n, the word length in terms of S of every permutation is bounded above by a polynomial of n. We prove this conjecture for sets of generators containing a permutation fixing at least 37% of the points.Comment: 17 pages, 6 table

    Measurement of correlations between low-frequency vibrational modes and particle rearrangements in quasi-two-dimensional colloidal glasses

    Get PDF
    We investigate correlations between low-frequency vibrational modes and rearrangements in two-dimensional colloidal glasses composed of thermosensitive microgel particles which readily permit variation of sample packing fraction. At each packing fraction, the particle displacement covariance matrix is measured and used to extract the vibrational spectrum of the "shadow" colloidal glass (i.e., the particle network with the same geometry and interactions as the sample colloid but absent damping). Rearrangements are induced by successive, small reductions in packing fraction. The experimental results suggest that low-frequency quasi-localized phonon modes in colloidal glasses, i.e., modes that present low energy barriers for system rearrangements, are spatially correlated with rearrangements in this thermal system

    Exploratory Analysis of Highly Heterogeneous Document Collections

    Full text link
    We present an effective multifaceted system for exploratory analysis of highly heterogeneous document collections. Our system is based on intelligently tagging individual documents in a purely automated fashion and exploiting these tags in a powerful faceted browsing framework. Tagging strategies employed include both unsupervised and supervised approaches based on machine learning and natural language processing. As one of our key tagging strategies, we introduce the KERA algorithm (Keyword Extraction for Reports and Articles). KERA extracts topic-representative terms from individual documents in a purely unsupervised fashion and is revealed to be significantly more effective than state-of-the-art methods. Finally, we evaluate our system in its ability to help users locate documents pertaining to military critical technologies buried deep in a large heterogeneous sea of information.Comment: 9 pages; KDD 2013: 19th ACM SIGKDD Conference on Knowledge Discovery and Data Minin

    How contextual constraints shape mid-career high school teachers’ stress management and use of digital support tools: A qualitative study

    Get PDF
    Background: Persistent psychosocial stress is endemic in the modern workplace, including among midcareer high school (secondary comprehensive) teachers in England. Understanding contextual influences on teachers' self-management of stress along with their use of digital health technologies could provide important insights into creating more usable and accessible stress support interventions. Objective: The aim of this study was to investigate the constraints on stress management and prevention among teachers in the school environment and how this shapes the use of digitally enabled stress management tools. Methods: Semistructured interviews were conducted with 14 teachers from southern England. The interviews were analyzed using thematic analysis. Results: Teachers were unanimous in their recognition of workplace stress, describing physical (such as isolation and scheduling) and cultural (such as stigma and individualism) aspects in the workplace context, which influence their ability to manage stress. A total of 12 participants engaged with technology to self-manage their physical or psychological well-being, with more than half of the participants using consumer wearables, but Web-based or smartphone apps were rarely accessed in school. However, digital well-being interventions recommended by school leaders could potentially be trusted and adopted. Conclusions: The findings from this study bring together both the important cultural and physical contextual constraints on the ability of midcareer high school teachers to manage workplace stress. This study highlights correlates of stress and offers initial insight into how digital health interventions are currently being used to help with stress, both within and outside high schools. The findings add another step toward designing tailored digital stress support for teachers

    A five year record of high-frequency in situ measurements of non-methane hydrocarbons at Mace Head, Ireland

    Get PDF
    Continuous high-frequency in situ measurements of a range of non-methane hydrocarbons have been made at Mace Head since January 2005. Mace Head is a background Northern Hemispheric site situated on the eastern edge of the Atlantic. Five year measurements (2005–2009) of six C&lt;sub&gt;2&lt;/sub&gt;–C&lt;sub&gt;5&lt;/sub&gt; non-methane hydrocarbons have been separated into baseline Northern Hemispheric and European polluted air masses, among other sectors. Seasonal cycles in baseline Northern Hemispheric air masses and European polluted air masses arriving at Mace Head have been studied. Baseline air masses show a broad summer minima between June and September for shorter lived species, longer lived species show summer minima in July/August. All species displayed a winter maxima in February. European air masses showed baseline elevated mole fractions for all non-methane hydrocarbons. Largest elevations (of up to 360 ppt for ethane maxima) from baseline data were observed in winter maxima, with smaller elevations observed during the summer. Analysis of temporal trends using the Mann-Kendall test showed small (&lt;6 % yr&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) but statistically significant decreases in the butanes and &lt;i&gt;i&lt;/i&gt;-pentane between 2005 and 2009 in European air. No significant trends were found for any species in baseline air
    corecore