268 research outputs found

    Assessment of the influence of intrinsic environmental and geographical factors on the bacterial ecology of pit latrines

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    Funding Information: This research received financial support from the Bill and Melinda Gates Foundation (grant number OPP52641). AWW and JP were supported by the Wellcome Trust [grant number 098051]. AWW and the Rowett Institute of Nutrition and Health, University of Aberdeen, receive core funding support from the Scottish Government Rural and Environmental Science and Analysis Service (RESAS). UZ is funded by Natural Environment Research Council (NERC) Independent Research Fellowship (NE/L011956/1). CQ is funded through an Medical Research Council fellowship (MR/M50161X/1) as part of the MRC Cloud Infrastructure for Microbial Bioinformatics consortium (MR/L015080/1).Peer reviewedPublisher PD

    Prevalence and persistence of Listeria monocytogenes in premises and products of small food business operators in Northern Ireland

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    peer-reviewedListeriosis is a foodborne disease, with a high mortality rate, that predominantly affects the elderly. Under European Union legislation, EC 2073/2005, food business operators are encouraged to undertake sampling to ensure that the food processing environment, and required to ensure that food products, are free of Listeria monocytogenes. To determine the prevalence of L. monocytogenes in smaller food processing facilities in Northern Ireland, 24 companies submitted six processing environment swabs and two food samples every two months for eighteen months (July 2015 to November 2016) for L. monocytogenes examination. The prevalence of L. monocytogenes was 4.6% in food samples, and 6.3% in processing environment swabs. Over the duration of the study, 96 isolates of L. monocytogenes were obtained, one from each positive sample, except for two meat samples that had >100ā€Æcfu/g, where two isolates were obtained from each sample. No seasonality in occurrence of L. monocytogenes was seen for food isolates but significantly higher numbers of positive processing environment swabs were found in the warmer months of May, July and September (pā€Æ=ā€Æ.007). Pulsed Field Gel Electrophoresis (PFGE) analysis revealed the presence of 27 pulsotypes; 9 pulsotypes were shared between different facilities and 9 were persistent. Based on a Combase predictive growth model, 77.5% (nā€Æ=ā€Æ130) of the foods tested were predicted to support the growth of L. monocytogenes. All of the isolates carried the pathogenicity genes inlA and actA and 71.4% carried qacH, which confers resistance to quaternary ammonium compounds which are frequently used in sanitizers. Whole genome sequencing of the isolates allowed multi-locus sequence typing to be undertaken. The data indicated that the sequence types identified included those with disease-causing ability, highlighting the disease-causing potential of the isolates

    Comparison of Infrared and Visible Imagery for Object Tracking: Toward Trackers with Superior IR Performance

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    The subject of this paper is the visual object tracking in infrared (IR) videos. Our contribution is twofold. First, the performance behaviour of the state-of-the-art trackers is investigated via a comparative study using IR-visible band video conjugates, i.e., video pairs captured observing the same scene simultaneously, to identify the IR specific challenges. Second, we propose a novel ensemble based tracking method that is tuned to IR data. The proposed algorithm sequentially constructs and maintains a dynamical ensemble of simple correlators and produces tracking decisions by switching among the ensemble correlators depending on the target appearance in a computationally highly efficient manner We empirically show that our algorithm significantly outperforms the state-of-the-art trackers in our extensive set of experiments with IR imagery

    Virulence characteristics of hcp (+) Campylobacter jejuni and Campylobacter coli isolates from retail chicken.

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    BACKGROUND: Recently the Type VI secretion system (T6SS), which can play a significant role in bacterial survival and pathogenesis, was reported in Campylobacter spp., having the hcp gene as a key component. METHODS: Campylobacteriosis is associated with the consumption of infected chicken meat. Our study aimed to explore the presence of T6SS in C. jejuni (nĀ =Ā 59) and C. coli (nĀ =Ā 57) isolates, from retail raw chicken and to investigate their pathogenic potential. The hcp gene was used as an indicator for the T6SS presence. RESULTS: Using multiplex PCR we have identified a significantly higher prevalence of hcp in C. coli isolates (56.1%) than in C. jejuni (28.8%) and AFLP analysis of the isolates showed a high degree of genetic similarity between the isolates carrying the hcp gene. Genome sequencing data showed that 84.3% of the C. coli and 93.7% of the C. jejuni isolates had all 13 T6SS open reading frames. Moreover, the virulence characteristics of hcpĀ +Ā isolates, including motility and the ability to invade human intestinal epithelial cells in vitro, were significantly greater than in the control strain C. jejuni 12502; a human isolate which is hcp positive. CONCLUSION: Overall, it was discovered that hcp (+) C. coli and C. jejuni isolated from retail chicken isolates posses genetic and phenotypic properties associated with enhanced virulence. However, since human infections with C. coli are significantly less frequent than those of C. jejuni, the relationship between virulence factors and pathogenesis requires further study

    Simultaneous preconcentration of trace metals in environmental samples using amberlite XAD-2010/8-hydroxyquinoline system

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    A simple and sensitive system for simultaneous preconcentration of Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Pb(II) and Cd(II) at trace level by flame atomic absorption spectrometry (FAAS) is proposed. Amberlite XAD-2010 packed in a column was used as sorbent. Analyte ions were sorbed in the column as their 8-hydroxyquinoline chelates; they could then be eluted by 1 mol L -1 HNO3 in acetone. The analytical conditions including pH, amounts of 8-hydroxyquinoline, sample volume etc. on the quantitative recoveries of the analytes were investigated. The effects of the concomitants ions on the recoveries of the analytes column were also studied. The detection limits, corresponding to three times the standard deviation of the blank, were found to be in the range of 0.10-0.40 Ī¼g L-1. The accuracy of the procedure was measured by analyte determinations in certified reference materials (CRM NIES No. 7 Tea Leaves and TMDW-500 Drinking Water). The applications of the presented system were performed by the analysis of some environmental samples including water samples

    Scheduling of grid tied battery energy storage system participating in frequency response services and energy arbitrage

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    Battery energy storage systems (BESS) are widely used to smooth power fluctuations and maintain the voltage and frequency of the power feeder at a desired level. T he National Grid Electricity Transmission (NGET), the primary electricity transmission network operator in the UK, has introduced various frequency response servic es that are designed to provide a real - time response to deviations in the grid frequency. In this study , a control algorithm is developed which generates a charge/discharge power output with respect to deviations in the grid frequency and the requisite service specifications. Using historical UK electricity prices, a new balancing service scheduling approach has also been developed to maximize energy arbitrage revenue by layering different types of balancing services throughout the day . Simulation result s show that the proposed algorithm delivers both dynamic and non - dynamic firm frequency response (FFR) and also enhanced frequency response (EFR) to NGET specifications while generating arbitrage revenue as well as service availability payment s in the balancing market. A comparative study is also presented to compare the yearly arbitrage revenue obtained from the work presented in this paper and a previous reference study . Finall y, exper imental results of a grid - tied 2MW /1MWh BESS have been used for verification purposes

    Analysis of pit latrine microbiota reveals depth-related variation in composition, and key parameters and taxa associated with latrine fill-up rate

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    Funding statement This research received financial support from the Bill and Melinda Gates Foundation (grant number OPP52641 to the London School of Hygiene and Tropical Medicine). AWW and JP were supported by the Wellcome Trust [grant number 098051]. AWW and the Rowett Institute, University of Aberdeen, receive core funding support from the Scottish Government Rural and Environmental Science and In review Analysis Service (RESAS). UZI is funded by NERC Independent Research Fellowship (NE/L011956/1) and further supported by EPSRC (EP/P029329/1 and EP/V030515/1). CQ is funded through an MRC fellowship (MR/M50161X/1) as part of the MRC Cloud Infrastructure for Microbial Bioinformatics consortium (MR/L015080/1). Acknowledgements In review Pit latrine microbiota associated with depth and fill-up rate. We would like to thank all the field and laboratory teams and to all the pit latrine owners who participated in this study. We also thank Paul Scott, Richard Rance and members of the Wellcome Sanger Institute's sequencing team for generating 16S rRNA gene data.Peer reviewedPublisher PD

    Determination of changes in the microbial and chemical composition of Taga cheese during maturation

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    Publication history: Accepted - 9 November 2020; Published online - 3 December 2020Țaga cheese is a traditional Romanian smear-ripened cheese made from bovine milk and identified with the name of the village and caves where it is produced. As no previously reported microbiological and chemical studies have been undertaken on this product, this research aimed to investigate the microbiological and biochemical characteristics which ensure the uniqueness of Țaga cheese during the ripening process, to inform producers as to key quality determinants. Cheese samples, consisting of retail blocks, were collected on days 2, 5, 12, 18, and 25 of the ripening process. The evolution of lactic microbiota during the production and maturation of traditional cheeses involves isolating lactic acid microorganisms present in cheese. Cheese samples were analyzed for pH, fat, NaCl, fatty acids, and volatile compounds. The microbial ecosystem naturally changes during the maturation process, leading to variation in the microorganisms involved during ripening. Our results show that specific bacteria were identified in high levels during the entire ripening process and may be responsible for milk fat lipolysis contributing directly to cheese flavor by imparting detailed fatty acid flavor notes, or indirectly as precursors formation of other flavor compounds.This paper was published with the support of the Romanian Ministry of Research and Innovation through Program 1 - Development of the National Research and Development System, Subprogram 1.2-Institutional Performance - Projects for Financing the Excellence in CDI, Contract No. 37PFE-2018-2020
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