841 research outputs found
Critical reflections on designing product service systems
In response to unsustainability and the prospect of resource scarcity, lifestyles dominated by resource throughput are being challenged. This paper focuses on a design experiment that sought to introduce alternative resource consumption pathways in the form of product service systems (PSS) to satisfy household demand and reduce consumer durable household waste. In contrast to many other PSS examples this project did not begin with sustainability benefits, rather the preferences of supply and demand actors and the bounded geographical locations represented by two UK housing developments. The paper addresses the process through which the concept PSS were designed, selected and evaluated, alongside the practical and commercial parameters of the project. It proposes the need for a shift to further emphasize the importance of the design imperative in creating different PSS outcomes that reorganize relationships between people, resources and the environment
A manifesto for cyborg pedagogy?
This paper was published in International Research in Geographical and Environmental Education, 10 (2), pp. 195 - 201, 2001. © 2001 T. Angus et al.This paper seeks to give an impression of what can happen if teachers encourage their
students to take personally the issues they study, and to think and to write about how
their identities and everyday lives are inseparable from the kinds of issues studied in the geography classroom. It discusses three principles – situated knowledge, cyborg ontologies and border pedagogy – which have guided the organisation of an undergraduate course on the geographies of material culture. This attempts to get students to think through their connections with the lives of distant others through simple acts of consumption, and the responsibilities which they might therefore have. This paper illustrates the kinds of student writing that can come out of such a course and the ways in which this issue of responsibility should be, and is, talked about
Residential exposure to traffic emissions and adverse pregnancy outcomes
Motor vehicle traffic emissions are the single largest contributor to ambient air pollution in many developed countries and it has been suggested that these emissions can affect outcomes of pregnancy. An individual's exposure experience is greatly influenced by where they live as emission concentrations are much higher closer to roads. A systematic review was conducted using the MOOSE guidelines in order to synthesise studies published 1989-2009 which investigated pregnancy outcomes in relation to residential exposure to traffic emissions. Twelve studies met the inclusion criteria and were consequently reviewed. We identified exposure assessment methods and the scope of health endpoints that have been investigated. Gestational duration, intrauterine growth, mortality and pregnancy complications have been studied using simple distance, distance-weighted traffic density, annually averaged daily traffic counts, dispersion models and land-use regression models. Few studies investigated mortality and pregnancy complications and no study investigated the risk of congenital anomalies. The evidence to date suggests an adverse effect was consistently reported for gestational duration and less consistently reported yet plausible for intrauterine growth. However, the small number of studies, the possibility of publication bias and the limited research conducted on biological mechanisms precluded more formal statements on the existence of an effect. The ubiquity of motor vehicle traffic emissions, the biological vulnerability of the fetus, and the adverse associations detected among many of the twelve reviewed studies motivates a multidisciplinary collaborative effort toward further research on the topic
Use of a total traffic count metric to investigate the impact of roadways on asthma severity: A case-control study
Background: This study had two principal objectives: (i) to investigate the relationship between asthma severity and proximity to major roadways in Perth, Western Australia; (ii) to demonstrate a more accurate method of exposure assessment for traffic pollutants using an innovative GIS-based measure that fully integrates all traffic densities around subject residences. Methods. We conducted a spatial case-control study, in which 'cases' were defined as individuals aged under 19 years of age with more severe asthma (defined here as two or more emergency department contacts with asthma in a defined 5-year period) versus age- and gender-matched 'controls' with less severe asthma (defined here as one emergency department contact for asthma). Traffic exposures were measured using a GIS-based approach to determine the lengths of the roads falling within a buffer area, and then multiplying them by their respective traffic counts. Results: We examined the spatial relationship between emergency department contacts for asthma at three different buffer sizes: 50 metres, 100 metres and 150 metres. No effect was noted for the 50 metre buffer (OR = 1.07; 95% CI: 0.91-1.26), but elevated odds ratios were observed with for crude (unadjusted) estimates OR = 1.21 (95% CI: 1.00-1.46) for 100 metre buffers and OR = 1.25 (95% CI: 1.02-1.54) for 150 metre buffers. For adjusted risk estimates, only the 150 metre buffer yielded a statistically significant finding (OR = 1.24; 95% CI:1.00-1.52). Conclusions: Our study revealed a significant 24% increase in the risk of experiencing multiple emergency department contacts for asthma for every log-unit of traffic exposure. This study provides support for the hypothesis that traffic related air pollution increases the frequency of health service contacts for asthma. This study used advanced GIS techniques to establish traffic-weighted buffer zones around the geocoded residential location of subjects to provide an accurate assessment of exposure to traffic emissions, thereby providing a quantification of the ranges over which pollutants may exert a health effect
When do fractured media become seismically anisotropic? Some implications on quantifying fracture properties
Fractures are pervasive features within the Earth's crust and they have a significant influence on the multi-physical response of the subsurface. The presence of coherent fracture sets often leads to observable seismic anisotropy enabling seismic techniques to remotely locate and characterise fracture systems. In this study, we confirm the general scale-dependence of seismic anisotropy and provide new results specific to shear-wave splitting (SWS). We find that SWS develops under conditions when the ratio of wavelength to fracture size (λS/d) is greater than 3, where Rayleigh scattering from coherent fractures leads to an effective anisotropy such that effective medium model (EMM) theory is qualitatively valid. When 1<λS/d<3 there is a transition from Rayleigh to Mie scattering, where no effective anisotropy develops and hence the SWS measurements are unstable. When λS/d<1 we observe geometric scattering and begin to see behaviour similar to transverse isotropy. We find that seismic anisotropy is more sensitive to fracture density than fracture compliance ratio. More importantly, we observe that the transition from scattering to an effective anisotropic regime occurs over a propagation distance between 1 and 2 wavelengths depending on the fracture density and compliance ratio. The existence of a transition zone means that inversion of seismic anisotropy parameters based on EMM will be fundamentally biased. More importantly, we observe that linear slip EMM commonly used in inverting fracture properties is inconsistent with our results and leads to errors of approximately 400% in fracture spacing (equivalent to fracture density) and 60% in fracture compliance. Although EMM representations can yield reliable estimates of fracture orientation and spatial location, our results show that EMM representations will systematically fail in providing quantitatively accurate estimates of other physical fracture properties, such as fracture density and compliance. Thus more robust and accurate quantitative estimates of in situ fracture properties will require improvements to effective medium models as well as the incorporation of full-waveform inversion techniques
Radioactive isotope analyses of skeletal materials in forensic science: a review of uses and potential uses
A review of information that can be provided from measurements made on natural and anthropogenic radionuclide activities in human skeletal remains has been undertaken to establish what reliable information of forensic anthropological use can be obtained regarding years of birth and death (and hence post-mortem interval (PMI)). Of the anthropogenic radionuclides that have entered the environment, radiocarbon (14C) can currently be used to generate the most useful and reliable information. Measurements on single bones can indicate whether or not the person died during the nuclear era, while recent research suggests that measurements on trabecular bone may, depending on the chronological age of the remains, provide estimates of year of death and hence PMI. Additionally, 14C measurements made on different components of single teeth or on teeth formed at different times can provide estimates of year of birth to within 1–2 years of the true year. Of the other anthropogenic radionuclides, 90Sr shows some promise but there are problems of (1) variations in activities between individuals, (2) relatively large analytical uncertainties and (3) diagenetic contamination. With respect to natural series radionuclides, it is concluded that there is no convincing evidence that 210Pb dating can be used in a rigorous, quantitative fashion to establish a PMI. Similarly, for daughter/parent pairs such as 210Po/210Pb (from the 238U decay series) and 228Th/228Ra (from the 232Th decay series), the combination of analytical uncertainty and uncertainty in activity ratios at the point of death inevitably results in major uncertainty in any estimate of PMI. However, observation of the disequilibrium between these two daughter/parent pairs could potentially be used in a qualitative way to support other forensic evidence
Residential traffic exposure and children's emergency department presentation for asthma: a spatial study
<p>Abstract</p> <p>Background</p> <p>There is increasing evidence that residential proximity to roadways is associated with an elevated risk of asthma exacerbation. However, there is no consensus on the distance at which these health effects diminishes to background levels. Therefore the optimal, clinically relevant measure of exposure remains uncertain. Using four spatially defined exposure metrics, we evaluated the association between residential proximity to roadways and emergency department (ED) presentation for asthma in Perth, Western Australia.</p> <p>Method</p> <p>The study population consisted of 1809 children aged between 0 and 19 years who had presented at an ED between 2002 and 2006 and were resident in a south-west metropolitan area of Perth traversed by major motorways. We used a 1:2 matched case-control study with gastroenteritis and upper limb injury as the control conditions. To estimate exposure to traffic emissions, we used 4 contrasting methods and 2 independently derived sources of traffic data (video-monitored traffic counts and those obtained from the state government road authority). The following estimates of traffic exposure were compared: (1) a point pattern method, (2) a distance-weighted traffic exposure method, (3) a simple distance method and (4) a road length method.</p> <p>Results</p> <p>Risk estimates were sensitive to socio-economic gradients and the type of exposure method that was applied. Unexpectedly, a range of apparent <it>protective </it>effects were observed for some exposure metrics. The kernel density measure demonstrated more than a 2-fold (OR 2.51, 95% CI 2.00 - 3.15) increased risk of asthma ED presentation for the high exposure group compared to the low exposure group.</p> <p>Conclusion</p> <p>We assessed exposure using traffic data from 2 independent sources and compared the results of 4 different exposure metric types. The results indicate that traffic congestion may be one of the most important aspects of traffic-related exposures, despite being overlooked in many studies on the exacerbation of asthma.</p
Risk of Birth Defects in Australian Communities with High Levels of Brominated Disinfection By-products
A pragmatic, multicentre, randomised controlled trial comparing stapled haemorrhoidopexy to traditional excisional surgery for haemorrhoidal disease (eTHoS): study protocol for a randomised controlled trial
Background: Current interventions for haemorrhoidal disease include traditional haemorrhoidectomy (TH) and
stapled haemorrhoidopexy (SH) surgery. However, uncertainty remains as to how they compare from a clinical,
quality of life (QoL) and economic perspective. The study is therefore designed to determine whether SH is more
effective and more cost-effective, compared with TH.
Methods/Design: eTHoS (either Traditional Haemorrhoidectomy or Stapled Haemorrhoidopexy for Haemorrhoidal
Disease) is a pragmatic, multicentre, randomised controlled trial. Currently, 29 secondary care centres are open to
recruitment. Patients, aged 18 year or older, with circumferential haemorrhoids grade II to IV, are eligible to take part.
The primary clinical and economic outcomes are QoL profile (area under the curve derived from the EuroQol Group’s 5
Dimension Health Status Questionnaire (EQ-5D) at all assessment points) and incremental cost per quality adjusted life
year (QALY) based on the responses to the EQ-5D at 24 months. The secondary outcomes include a comparison of the
SF-36 scores, pain and symptoms sub-domains, disease recurrence, complication rates and direct and indirect costs
to the National Health Service (NHS). A sample size of n =338 per group has been calculated to provide 90% power
to detect a difference in the mean area under the curve (AUC) of 0.25 standard deviations derived from EQ-5D
score measurements, with a two-sided significance level of 5%. Allowing for non-response, 400 participants will
be randomised per group. Randomisation will utilise a minimisation algorithm that incorporates centre, grade of
haemorrhoidal disease, baseline EQ-5D score and gender. Blinding of participants and outcome assessors is not
attempted.
Discussion: This is one of the largest trials of its kind. In the United Kingdom alone, 29,000 operations for haemorrhoidal
disease are done annually. The trial is therefore designed to give robust evidence on which clinicians and health
service managers can base management decisions and, more importantly, patients can make informed choices.
Trial registration: Current Controlled Trials ISRCTN80061723 (assigned 8 March 2010
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