A Futures Approach to Water Distribution and Sewer Network (RE)Design

When designing urban water systems (i.e. water distribution and sewer systems) it is imperative that uncertainty is taken into consideration. However, this is a challenging problem due to the inherent uncertainty associated with both system loading requirements and the potential for physical components failure. It is therefore desirable to improve the reliability of each system in order to account for these uncertainties. Although it is possible to directly evaluate the reliability of a water distribution systems (WDS) (using reliability measures), the calculation processes involved are computationally intensive and therefore unsuitable for some state-of-the-art, iterative design approaches (such as optimisation). Consequently, interest has recently grown in the use of reliability indicators, which are simpler and faster to evaluate than conventional direct reliability methods. In this thesis, a novel measure (the RUF) is developed to quantify reliability in urban water systems with a view to enhance their robustness under a range of future scenarios (Policy Reform, Market Forces, Fortress World and New-Sustainability Paradigm). The considered four future scenarios were synthesized in the EPSRC supported multidisciplinary 4 year project: Urban Futures. Each investigated urban future scenario is characterised by a distinct household water demand and local demand distribution (emerging due to different urban forms evolving in future scenarios). In order to assess the impact of urban futures, RUF has been incorporated into Urban Water System (UWS) dynamic simulations for both WDSs and Foul Sewer Systems (FSSs) using open source codes of EPANET and SWMM. Additionally, in order to overcome extensive computational effort, resulting from the use of traditional reliability measures, a new holistic reliability indicator, the hydraulic power entropy (IHPE) has been developed and compared to existing reliability indicators. Additionally, the relationship between the new reliability indicator and the above mentioned RUF reliability measure is investigated. Results suggest that the magnitude of the IHPE in network solutions provides a holistic indication of the hydraulic performance and reliability for a WDS. However, the performance of optimal solutions under some Urban Futures indicates that additional design interventions are required in order to achieve desired future operation. This thesis also proposes a new holistic foul sewer system (FSS) reliability indicator (the IFSR). The IFSR represents sewer performance as a function of excess pipe capacity (in terms of available increase and also decrease in inflow). The indicator has been tested for two case studies (i.e. different sewer network layouts). Results suggest that the magnitude of IFSR has positive correlations with a number of identified key performance indicators (i.e. relating to capacity, velocity, blockages). Finally, an Integrated Design Approach (IDA) has been developed in order to assess the implications of applying design interventions on both a WDS and downstream FSS. The approach holistically considers present and future operation of each interconnected system. The approach was subsequently demonstrated using two proposed design interventions. Results suggest that, for the considered design interventions, there is trade-off between the simultaneous improvement of both WDS and FSS operation and reliability

Issues in the development of advance directives in mental health care

<i>Background</i>: Interest in advance directives in mental health care is growing internationally. There is no clear universal agreement as to what such an advance directive is or how it should function. <i>Aim</i>: To describe the range of issues embodied in the development of advance directives in mental health care. <i>Method</i>: The literature on advance directives is examined to highlight the pros and cons of different versions of advance directive. <i>Results</i>: Themes emerged around issues of terminology, competency and consent, the legal status of advance directives independent or collaborative directives and their content. Opinions vary between a unilateral legally enforceable instrument to a care plan agreed between patient and clinician. <i>Conclusion</i>: There is immediate appeal in a liberal democracy that values individual freedom and autonomy in giving weight to advance directives in mental health care. They do not, however, solve all the problems of enforced treatment and early access to treatment. They also raise new issues and highlight persistent problems. <i>Declaration</i> <i>of</i> <i>interest</i>: The research was funded by the Nuffield Foundation grant number MNH/00015G

Reliability indicators for water distribution system design: comparison

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.When designing a water distribution system (WDS), it is imperative that the reliability of the network is taken into consideration. It is possible to directly evaluate the reliability of a WDS, although the calculation processes involved are computationally intensive and thus undesirable for some state-of-the-art, iterative design approaches (such as optimization). Consequently, interest has recently grown in the use of reliability indicators, which are simpler and faster to evaluate than direct reliability methods. In this study, two existing reliability indicators, the Todini resilience index and entropy for WDS, are examined by analyzing their relationships with different subcategories of reliability, namely the mechanical (network tolerance to pipe failure) and hydraulic reliability (network tolerance to demand change). The analysis is performed by generating comparable solutions through multiobjective optimization of cost against the chosen indicators using the well known Anytown WDS benchmark as a case study. It is found that WDS solutions with high entropy have increased mechanical reliability, yet are expensive and have poor hydraulic operation and water quality. In contrast, high resilience index networks are relatively cheaper and present reasonable hydraulic operational performance, yet have limited improvement in mechanical reliability. Both indicators appear to be correlated to hydraulic reliability, but each has its own associated disadvantages. Including minimum surplus head as an additional objective in the optimization of the reliability indicators appeared to improve the performance. When optimized together, a trade-off between the two indicators is identified, implying that significantly increasing both simultaneously is not possible, and thus a new indicator is recommended to account for both the mechanical and hydraulic reliability while ensuring reasonable standards of hydraulic operation.This work was supported by the UK Engineering and Physical Science Research Council as part of the Urban Futures Project (EP/F007426/1)

Continuous estimate of Atlantic oceanic freshwater flux at 26.5°N

The first continuous estimates of freshwater flux across 26.5°N are calculated using observations from the RAPID–MOCHA–Western Boundary Time Series (WBTS) and Argo floats every 10 days between April 2004 and October 2012. The mean plus or minus the standard deviation of the freshwater flux (FW) is −1.17 ± 0.20 Sv (1 Sv ≡ 106 m3 s−1; negative flux is southward), implying a freshwater divergence of −0.37 ± 0.20 Sv between the Bering Strait and 26.5°N. This is in the sense of an input of 0.37 Sv of freshwater into the ocean, consistent with a region where precipitation dominates over evaporation. The sign and the variability of the freshwater divergence are dominated by the overturning component (−0.78 ± 0.21 Sv). The horizontal component of the freshwater divergence is smaller, associated with little variability and positive (0.35 ± 0.04 Sv). A linear relationship, describing 91% of the variance, exists between the strength of the meridional overturning circulation (MOC) and the freshwater flux (−0.37 − 0.047 Sv of FW per Sverdrups of MOC). The time series of the residual to this relationship shows a small (0.02 Sv in 8.5 yr) but detectable decrease in the freshwater flux (i.e., an increase in the southward freshwater flux) for a given MOC strength. Historical analyses of observations at 24.5°N are consistent with a more negative freshwater divergence from −0.03 to −0.37 Sv since 1974. This change is associated with an increased southward freshwater flux at this latitude due to an increase in the Florida Straits salinity (and therefore the northward salinity flux)

Overview of using visualisation in programming learning

There is a high demand for mechanisms that support programming teaching, particularly in finding a solution to the bottleneck in programming education. Nowadays, different methods of teaching can support the learning process and motivate students to learn. These methods improve the thinking and creativity that lead to defining and analysing the problem of supporting programming learning to devise ideal solutions. Approaches such as visualising the code or using a memory diagram to trace the program’s execution have made a vital contribution to the process of teaching and learning how to program. The purpose of this paper is to provide an overview of studies that have been conducted in visualisation to support programming learning. Moreover, tools that follow the visualisation and memory-referencing approach will be investigated in this paper

Epigenetic regulation of the telomerase gene promoters

Epigenetic mechanisms have been implicated in the regulation of telomerase gene expression and here we show that specific modifications within the chromatin environment of the hTR and hTERT promoters correlate with expression of hTR and hTERT in ALT, normal and telomerase-positive tumour cell lines. Lack of expression of hTR and hTERT is associated with repressive histone modification, while, hTR and hTERT expression is associated permissive histone modifications. Methylation of lysine 20 H4 was not linked to gene expression but instead was specific to the hTR and hTERT promoters of ALT cells providing an insight into the differences between ALT and telomerase-positive cells as well as a novel marker for the ALT phenotype. Basal transcription machinery dynamics were also shown to be different between normal and cancer cells at the telomerase gene promoters. Modulation of the chromatin environment was also shown to cause re-expression or increased expression of hTR and hTERT further supporting the role of the chromatin environment in controlling telomerase gene expression. Epigenetic mechanisms are also shown to be involved in the repression of hTERT transcription in human mesenchymal stem cell (hMSCs) and modulation of the chromatin environment is shown to allow re-expression of hTERT expression, while the disruption of telomerase gene expression in human haematopoietic stem cells (hHSCs) in chronic myeloid leukaemia (CML) and the role of the chromatin environment was also studied. These data establishes how epigenetic mechanisms can contribute to transcriptional regulation of telomerase and also highlights the potential importance of epigenetics in senescence and tumourigenicity

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Lack of support for Rensch's rule in an intraspecific test using red flour beetle (Tribolium castaneum) populations

Rensch's rule proposes a universal allometric scaling phenomenon across species where sexual size dimorphism (SSD) has evolved: in taxa with male‐biased dimorphism, degree of SSD should increase with overall body size, and in taxa with female‐biased dimorphism, degree of SSD should decrease with increasing average body size. Rensch's rule appears to hold widely across taxa where SSD is male‐biased, but not consistently when SSD is female‐biased. Furthermore, studies addressing this question within species are rare, so it remains unclear whether this rule applies at the intraspecific level. We assess body size and SSD within Tribolium castaneum (Herbst), a species where females are larger than males, using 21 populations derived from separate locations across the world, and maintained in isolated laboratory culture for at least 20 years. Body size, and hence SSD patterns, are highly susceptible to variations in temperature, diet quality and other environmental factors. Crucially, here we nullify interference of such confounds as all populations were maintained under identical conditions (similar densities, standard diet and exposed to identical temperature, relative humidity and photoperiod). We measured thirty beetles of each sex for all populations, and found body size variation across populations, and (as expected) female‐biased SSD in all populations. We test whether Rensch's rule holds for our populations, but find isometry, i.e. no allometry for SSD. Our results thus show that Rensch's rule does not hold across populations within this species. Our intraspecific test matches previous interspecific studies showing that Rensch's rule fails in species with female‐biased SSD.The authors further thank NERC (Standard research grant to MJGG, BCE and OYM), Swiss National Science Foundation (postdoctoral fellowships and Ambizione grants to OYM), the University of East Anglia and ETH Zürich for support.Peer Reviewe