Quantifying the well-being benefits of urban green space

Rapid urbanisation compounded by underlying population growth has placed increasing pressures upon green space areas within cities. Anecdotal evidence suggests that such areas are major sources of wellbeing yet the complex nature of the services provided by such areas and the non-market, unpriced characteristics of the benefits they yield raise concerns that they are inadequately incorporated within decision making and planning systems. This thesis seeks to address the problem of quantifying the well-being benefits of urban green space through the extension of two complementary strands of research. The first seeks to contribute to the incorporation of urban green space benefits within conventional decision making systems. Within this strand of the research the authors report two studies designed to address various challenges associated with the estimation of economic values for the non-market benefits generated by urban green space. The first of these studies contributes to the literature on the estimation and transferral of valuation functions across locations to allocate available resources at an inter-city, national level. The second valuation study operates at an intra-city level through an experimental study the dimensions of which are designed to reveal optimal locations in the presence of potential local dis-amenities (a potentiality which is confirmed through the application of advanced statistical analysis techniques). The second strand of research addresses the complexities of relationships between urban green space and individual well-being. Here recent methodological advances in the field of applied social-psychology are extended to yield a richer picture of the diverse impact of both direct experience and passive viewing of green space upon wellbeing. An experiment is designed to permit enhanced controls for the potential correlation between environment and activity in determining experiential perceptions of well-being effects. A common theme of all applications is the explicit incorporation of spatial complexity and variation in the environment within each study and across the various methodologies employed. From a practical perspective it is argued that these results provide inputs to both the decision making and planning fields. More fundamentally, the work presented within this thesis represents a useful methodological contribution to both the applied economic valuation and social-psychology research literatures

Good Parks – Bad Parks: The Influence of Perceptions of Location on WTP and Preference Motives for Urban Parks

Urban parks generate substantial public benefits yet explicit economic assessments of such values remain relatively rare. Surveys of willingness to pay (WTP) were undertaken to assess such values for proposed new parks. The analysis assessed how preference motives and values varied according to the location of parks. Results revealed greater altruistic motivation and higher overall values for the creation of inner city as opposed to suburban parks. Spatial decomposition revealed that, after controlling for other determinants such as incomes, values generally increase for households closer to proposed parks, but that a significant downturn in values is evident for households located very close to a proposed inner city park; a finding which echoes concerns regarding the potential for such sites to provide a focus for antisocial behaviour. While these findings provide strong overall support for provision of public parks they highlight the importance of perceptions of location and the potential for localised dis-benefit

Could a mix of short- and long-term policies be the solution to tackle marine litter? Insights from a choice experiment in England and Ireland

Marine litter is a problem impacting the coasts and seas of the whole world. Whilst an increasing number of studies investigate the effects of marine litter on public welfare, most of the research to date considers it as a component of coastal environmental quality. This study specifically examines the preferences and willingness to pay of English and Irish respondents towards the removal and prevention of marine litter, and the trade-off between different short-term (e.g., beach clean-up) and long-term (e.g., ban on single use plastic) policy actions. An online survey, including a choice experiment and behavioural questions, was used to quantify the welfare impacts of marine litter on the provision of recreation and cultural ecosystem services. We found that respondents are generally inclined to the implementation of a policy mix, with propensity for immediate action. Our results confirm the loss of societal benefits due to the presence of marine litter on beaches. The estimated marginal willingness to pay can be used to inform the design and assess costs and benefits of new local, national or supra-national mixed policies directed at reducing litter in the coastal and marine environment

Caustic Formation in Tachyon Effective Field Theories

Certain configurations of D-branes, for example wrong dimensional branes or the brane-antibrane system, are unstable to decay. This instability is described by the appearance of a tachyonic mode in the spectrum of open strings ending on the brane(s). The decay of these unstable systems is described by the rolling of the tachyon field from the unstable maximum to the minimum of its potential. We analytically study the dynamics of the inhomogeneous tachyon field as it rolls towards the true vacuum of the theory in the context of several different tachyon effective actions. We find that the vacuum dynamics of these theories is remarkably similar and in particular we show that in all cases the tachyon field forms caustics where second and higher derivatives of the field blow up. The formation of caustics signals a pathology in the evolution since each of the effective actions considered is not reliable in the vicinity of a caustic. We speculate that the formation of caustics is an artifact of truncating the tachyon action, which should contain all orders of derivatives acting on the field, to a finite number of derivatives. Finally, we consider inhomogeneous solutions in p-adic string theory, a toy model of the bosonic tachyon which contains derivatives of all orders acting on the field. For a large class of initial conditions we conclusively show that the evolution is well behaved in this case. It is unclear if these caustics are a genuine prediction of string theory or not.Comment: 23 pages, 5 figures; accepted for publication in JHEP. Revised derivation of eikonal equation for the DBI action. Added comments concerning the relationship between p-adic string theory and tachyon matter. Added second example of inhomogeneous evolution in p-adic string theory. Misleading statements concerning caustic-free evolution removed, references adde

Palaeoenvironmental and diagenetic reconstruction of a closed-lacustrine carbonate system - the challenging marginal setting of the Miocene Ries Crater Lake (Germany)

Chemostratigraphic studies on lacustrine sedimentary sequences provide essential insights on past cyclic climatic events, on their repetition and prediction through time. Diagenetic overprint of primary features often hinders the use of such studies for palaeoenvironmental reconstruction. Here the potential of integrated geochemical and petrographic methods is evaluated to record freshwater to saline oscillations within the ancient marginal lacustrine carbonates of the Miocene Ries Crater Lake (Germany). This area is critical because it represents the transition from shoreline to proximal domains of a hydrologically closed system, affected by recurrent emergent events, representing the boundaries of successive sedimentary cycles. Chemostratigraphy targets shifts related to subaerial exposure and/or climatic fluctuations. Methods combine facies changes with δ13C–δ18O chemostratigraphy from matrix carbonates across five closely spaced, temporally equivalent stratigraphic sections. Isotope composition of ostracod shells, gastropods and cements is provided for comparison. Cathodoluminescence and back‐scatter electron microscopy were performed to discriminate primary (syn‐)depositional, from secondary diagenetic features. Meteoric diagenesis is expressed by substantial early dissolution and dark blue luminescent sparry cements carrying negative δ13C and δ18O. Sedimentary cycles are not correlated by isotope chemostratigraphy. Both matrix δ13C and δ18O range from ca −7·5 to +4·0‰ and show clear positive covariance (R = 0·97) whose nature differs from that of previous basin‐oriented studies on the lake: negative values are here unconnected to original freshwater lacustrine conditions but reflect extensive meteoric diagenesis, while positive values probably represent primary saline lake water chemistry. Noisy geochemical curves relate to heterogeneities in (primary) porosity, resulting in selective carbonate diagenesis. This study exemplifies that ancient lacustrine carbonates, despite extensive meteoric weathering, are able to retain key information for both palaeoenvironmental reconstruction and the understanding of diagenetic processes in relation to those primary conditions. Also, it emphasizes the limitation of chemostratigraphy in fossil carbonates, and specifically in settings that are sensitive for the preservation of primary environmental signals, such as lake margins prone to meteoric diagenesis

A Core Outcome Set for the Benefits and Adverse Events of Bariatric and Metabolic Surgery:the BARIACT project

BackgroundBariatric and metabolic surgery is used as a treatment for patients with severe and complex obesity. However, there is a need to improve outcome selection and reporting in bariatric surgery trials. A Core Outcome Set (COS), an agreed minimum set of outcomes reported in all studies of a specific condition, may achieve this. Here, we present the development of a COS for BARIAtric and metabolic surgery Clinical Trials-the BARIACT Study.Methods and findingsOutcomes identified from systematic reviews and patient interviews informed a questionnaire survey. Patients and health professionals were surveyed three times and asked to rate the importance of each item on a 1-9 scale. Delphi methods provided anonymised feedback to participants. Items not meeting predefined criteria were discarded between rounds. Remaining items were discussed at consensus meetings, held separately with patients and professionals, where the COS was agreed. Data sources identified 2,990 outcomes, which were used to develop a 130-item questionnaire. Round 1 response rates were moderate but subsequently improved to above 75% for other rounds. After rounds 2 and 3, 81 and 14 items were discarded, respectively, leaving 35 items for discussion at consensus meetings. The final COS included nine items: "weight," "diabetes status," "cardiovascular risk," "overall quality of life (QOL)," "mortality," "technical complications of the specific operation," "any re-operation/re-intervention," "dysphagia/regurgitation," and "micronutrient status." The main limitation of this study was that it was based in the United Kingdom only.ConclusionsThe COS is recommended to be used as a minimum in all trials of bariatric and metabolic surgery. Adoption of the COS will improve data synthesis and the value of research data. Future work will establish methods for the measurement of the outcomes in the COS

What Are the Real Procedural Costs of Bariatric Surgery? A Systematic Literature Review of Published Cost Analyses

This review aims to evaluate the current literature on the procedural costs of bariatric surgery for the treatment of severe obesity. Using a published framework for the conduct of micro-costing studies for surgical interventions, existing cost estimates from the literature are assessed for their accuracy, reliability and comprehensiveness based on their consideration of seven ‘important’ cost components. MEDLINE, PubMed, key journals and reference lists of included studies were searched up to January 2017. Eligible studies had to report per-case, total procedural costs for any type of bariatric surgery broken down into two or more individual cost components. A total of 998 citations were screened, of which 13 studies were included for analysis. Included studies were mainly conducted from a US hospital perspective, assessed either gastric bypass or adjustable gastric banding procedures and considered a range of different cost components. The mean total procedural costs for all included studies was US$14,389 (range, US$7423 to US$33,541). No study considered all of the recommended ‘important’ cost components and estimation methods were poorly reported. The accuracy, reliability and comprehensiveness of the existing cost estimates are, therefore, questionable. There is a need for a comparative cost analysis of the different approaches to bariatric surgery, with the most appropriate costing approach identified to be micro-costing methods. Such an analysis will not only be useful in estimating the relative cost-effectiveness of different surgeries but will also ensure appropriate reimbursement and budgeting by healthcare payers to ensure barriers to access this effective treatment by severely obese patients are minimised