665 research outputs found

    Dissecting the complex environment of a distant quasar with MUSE

    Get PDF
    High redshift quasars can be used to trace the early growth of massive galaxies and may be triggered by galaxy-galaxy interactions. We present MUSE science verification data on one such interacting system consisting of the well-studied z=3.2 PKS1614+051 quasar, its AGN companion galaxy and bridge of material radiating in Lyalpha between the quasar and its companion. We find a total of four companion galaxies (at least two galaxies are new discoveries), three of which reside within the likely virial radius of the quasar host, suggesting that the system will evolve into a massive elliptical galaxy by the present day. The MUSE data are of sufficient quality to split the extended Lyalpha emission line into narrow velocity channels. In these the gas can be seen extending towards each of the three neighbouring galaxies suggesting that the emission-line gas originates in a gravitational interaction between the galaxies and the quasar host. The photoionization source of this gas is less clear but is probably dominated by the two AGN. The quasar's Lyalpha emission spectrum is double-peaked, likely due to absorbing neutral material at the quasar's systemic redshift with a low column density as no damping wings are present. The spectral profiles of the AGN and bridge's Lyalpha emission are also consistent with absorption at the same redshift indicating this neutral material may extend over > 50 kpc. The fact that the neutral material is seen in the line of sight to the quasar and transverse to it, and the fact that we see the quasar and it also illuminates the emission-line bridge, suggests the quasar radiates isotropically and any obscuring torus is small. These results demonstrate the power of MUSE for investigating the dynamics of interacting systems at high redshift.Comment: 9 pages, 6 figures, published in MNRA

    Friend or Foe? A Case Study of iPad Usage During Small Group Reading Instruction

    Get PDF
    The purpose of this case study is to examine how two early childhood teachers in one university laboratory school utilize the iPad in their reading practices. Data collection involved: (a) observations, (b) audio recordings, and (c) researcher journal. Findings indicate that the teachers had a continuum of purposeful uses for the iPad and the associated applications during their small group reading instruction. In addition, the teachers had mixed overall perceptions toward using the iPad as an effective literacy tool. Implications for practice are presented

    Identifying clustering at high redshift through actively star-forming galaxies

    Get PDF
    Identifying galaxy clustering at high redshift (i.e. z > 1) is essential to our understanding of the current cosmological model. However, at increasing redshift, clusters evolve considerably in star-formation activity and so are less likely to be identified using the widely-used red sequence method. Here we assess the viability of instead identifying high redshift clustering using actively star-forming galaxies (SMGs associated with over-densities of BzKs/LBGs). We perform both a 2- and 3-D clustering analysis to determine whether or not true (3D) clustering can be identified where only 2D data are available. As expected, we find that 2D clustering signals are weak at best and inferred results are method dependant. In our 3D analysis, we identify 12 SMGs associated with an over-density of galaxies coincident both spatially and in redshift - just 8% of SMGs with known redshifts in our sample. Where an SMG in our target fields lacks a known redshift, their sightline is no more likely to display clustering than blank sky fields; prior redshift information for the SMG is required to identify a true clustering signal. We find that the strength of clustering in the volume around typical SMGs, while identifiable, is not exceptional. However, we identify a small number of highly clustered regions, all associated with an SMG. The most notable of these, surrounding LESSJ033336.8-274401, potentially contains an SMG, a QSO and 36 star-forming galaxies (a > 20sig over-density) all at z~1.8. This region is highly likely to represent an actively star-forming cluster and illustrates the success of using star-forming galaxies to select sites of early clustering. Given the increasing number of deep fields with large volumes of spectroscopy, or high quality and reliable photometric redshifts, this opens a new avenue for cluster identification in the young Universe.Comment: 24 pages, 14 figures, accepted MNRA

    Quantity and Quality Benefits of in-Service Invasive Cleaning of Trunk Mains

    Get PDF
    Trunk mains are high risk critical infrastructure where poor performance can impact on large numbers of customers. Both quantity (e.g. hydraulic capacity) and quality (e.g. discolouration) of trunk main performance are affected by asset deterioration in the form of particle accumulation at the pipe wall. Trunk main cleaning techniques are therefore desirable to remove such material. However, little is quantified regarding the efficacy of different maintenance interventions or longer-term changes following such cleaning. This paper presents an assessment of quantity and quality performance of a trunk main system pre, post and for 12 months following cleaning using pigging with ice slurry. Hydraulic calibration showed a 7 times roughness height reduction after ice slurry pigging, evidencing substantially improved hydraulic capacity and reduced headloss. Turbidity response due to carefully imposed shear stress increase remained significant after the cleaning intervention, showing that relatively loose material had not been fully removed from the pipe wall. Overall the results demonstrate that cleaning by pigging with ice slurry can be beneficial for quantity performance, but care and further assessment may be necessary to realise the full quality benefits

    A systematic review and thematic synthesis of patients' experience of medicines adherence

    Get PDF
    Background: Medicines non-adherence continues to be problematic in health care practice. After decades of research, few interventions have a robust evidence-based demonstrating their applicability to improve adherence. Phenomenology has a place within the health care research environment. Objective: To explore patients’ lived experiences of medicines adherence reported in the phenomenonologic literature. Methods: A systematic literature search was conducted to identify peer-reviewed and published phenomenological investigations in adults that aimed to investigate patients’ lived experiences of medicines adherence. Studies were appraised using the Critical Appraisal Skills Programme (CASP) Qualitative Research Tool. Thematic synthesis was conducted using a combination of manual coding and NVivo10 [QSR International, Melbourne] coding to aid data management. Results: Descriptive themes identified included i) dislike for medicines, ii) survival, iii) perceived need, including a) symptoms and side-effects and b) cost, and iv) routine. Analytic themes identified were i) identity and ii) interaction. Conclusions: This work describes adherence as a social interaction between the identity of patients and medicines, mediated by interaction with family, friends, health care professionals, the media and the medicine, itself. Health care professionals and policy makers should seek to re-locate adherence as a social phenomenon, directing the development of interventions to exploit patient interaction with wider society, such that patients ‘get to know’ their medicines, and how they can be taken, throughout the life of the patient and the prescription

    Impact of phosphate dosing on the microbial ecology of drinking water distribution systems: fieldwork studies in chlorinated networks

    Get PDF
    Phosphate is routinely dosed to ensure regulatory compliance for lead in drinking water distribution systems. Little is known about the impact of the phosphate dose on the microbial ecology in these systems and in particular the endemic biofilms. Disturbance of the biofilms and embedded material in distribution can cause regulatory failures for turbidity and metals. To investigate the impact of phosphate on developing biofilms, pipe wall material from four independent pipe sections was mobilised and collected using two twin-flushing operations a year apart in a chlorinated UK network pre- and post-phosphate dosing. Intensive monitoring was undertaken, including turbidity and water physico-chemistry, traditional microbial culture-based indicators, and microbial community structure via sequencing the 16S rRNA gene for bacteria and the ITS2 gene for fungi. Whole metagenome sequencing was used to study shifts in functional characteristics following the addition of phosphate. As an operational consequence, turbidity responses from the phosphate-enriched water were increased, particularly from cast iron pipes. Differences in the taxonomic composition of both bacteria and fungi were also observed, emphasising a community shift towards microorganisms able to use or metabolise phosphate. Phosphate increased the relative abundance of bacteria such as Pseudomonas, Paenibacillus, Massilia, Acinetobacter and the fungi Cadophora, Rhizophagus and Eupenicillium. Whole metagenome sequencing showed with phosphate a favouring of sequences related to Gram-negative bacterium type cell wall function, virions and thylakoids, but a reduction in the number of sequences associated to vitamin binding, methanogenesis and toxin biosynthesis. With current faecal indicator tests only providing risk detection in bulk water samples, this work improves understanding of how network changes effect microbial ecology and highlights the potential for new approaches to inform future monitoring or control strategies to protect drinking water quality

    Examining fault behaviour of a superconducting DC network

    Get PDF
    A large body of research is currently being conducted into superconducting power system applications, targeting improved efficiency and reductions in system size and weight. In order to attain the required levels of safety and reliability of the superconducting power system, effective protection systems, tailored to the specific fault behaviour of the novel components must also be in place. This paper presents a review of relevant literature concerning the dynamic and transient characteristics of superconducting DC networks and key associated components (such as superconducting cables and machines). This first part of a two stage Failure Modes and Effects Analysis (FMEA) is presented, which provides a conceptual consideration of expected physical failure modes and mechanisms. The effects on the wider network are discussed from which various protection considerations are drawn. A number of key research questions are drawn from this study, which will form the starting point of the second stage of the FMEA. The outputs from the FMEA will shape the protection requirements for a superconducting DC network

    Manipulating the fluorescence lifetime at the sub-cellular scale via photo-switchable barcoding

    Get PDF
    Fluorescent barcoding is a pivotal technique for the investigation of the microscale world, from information storage to the monitoring of dynamic biochemical processes. Using fluorescence lifetime as the readout modality offers more reproducible and quantitative outputs compared to conventional fluorescent barcoding, being independent of sample concentration and measurement methods. However, the use of fluorescence lifetime in this area has been limited by the lack of strategies that provide spatiotemporal manipulation of the coding process. In this study, we design a two-component photo-switchable nanogel that exhibits variable fluorescence lifetime upon photoisomerization-induced energy transfer processes through light irradiation. This remotely manipulated fluorescence lifetime property could be visually mapped using fluorescence lifetime imaging microscopy (FLIM), allowing selective storage and display of information at the microscale. Most importantly, the reversibility of this system further provides a strategy for minimizing the background influence in fluorescence lifetime imaging of live cells and sub-cellular organelles. Using fluorescence lifetime as the readout modality offers more reproducible and quantitative outputs compared to conventional fluorescent barcoding, being independent of sample concentration and measurement methods. Here, the authors design a photo-switchable nanogel exhibiting variable fluorescence lifetime, and demonstrate visual mapping by using fluorescence lifetime imaging microscopy on a sub-cellular scale.This work was supported by the ERC (grant number 615142), EPSRC, and the University of Birmingham, the Ministerio de Economia y Competitividad (MINECO) of Spain (project CTQ2016-80375-P) and the Basque Government (grant IT-324-07). The authors acknowledge the computational and technical and human support provided by DIPC. Y.X. acknowledges Chancellor's International Scholarship (University ofWarwick) for funding. All three reviewers are thanked for their time and contribution to the final version of this paper

    Algorithms to mimic human interpretation of turbidity events from drinking water distribution systems

    Get PDF
    Deriving insight from the increasing volume of water quality time series data from drinking water distribution systems is complex and is usually situation- and individual-specific. This research used crowd-sourcing exercises involving groups of domain experts to identify features of interest within turbidity time series data from operational systems. The resulting labels provide insight and a novel benchmark against which algorithmic approaches to mimic the human interpretation could be evaluated. Reflection of the results of the labelling exercises resulted in the proposal of a turbidity event scale consisting of advisory 4 NTU levels to inform utility response. Automation, for scale up, was designed to enable event detection within these categories, with the <2NTU category being the most challenging. A time-based averaging approach, based on data at the same time of day, was found to be most effective for identifying these advisory events. The automation of event detection and categorisation presented here provides the opportunity to gain actionable insight to safeguard drinking water quality from ageing infrastructure

    Determining the spatio-temporal relationship between water quality monitors in drinking water distribution systems

    Get PDF
    A novel method to both assess the strength of connectivity and determine hydraulic transit times between water quality monitors from time series data is reported. It was developed using a network of over 50 mobile multi-parameter sensors deployed for 18 months across a UK drinking water distribution system, and then validated using a network of 18 sensors from a different UK utility. Correlation coefficients are calculated at different time shifts for each possible sensor pair, with strength of connectivity represented by the highest correlation coefficient, and with the temporal lag of this highest correlation also designates the transit time. The results demonstrate the potential to derive valuable spatio-temporal information, with potential to increase understanding of system performance and connectivity. This information can be used to assist with further analytics such as tracking water quality events and improving hydraulic and disinfection residual decay modelling
    corecore