1,638 research outputs found
Thermodynamic insights and assessment of the ‘circular economy’
This study analyses the effect on energy use of applying a wide range of circular economy approaches. By collating evidence on specific quantifiable approaches and then calculating and analyzing their combined full supply chain impacts through input-output analysis, it provides a more complete assessment of the overall potential scope for energy savings that these approaches might deliver than provided elsewhere. Assessment is conducted globally, across the EU-27 and in the UK. Overall, the identified opportunities have the potential to save 6%–11% of energy used to support economic activity, worldwide and in the EU, and 5%–8% in the UK. Their potential is equivalent to the total scope for other industrial energy efficiency savings. The potential savings are further divided into those due to sets of approaches relating to food waste, steel production, other materials production, product refurbishment, vehicle provision, construction and other equipment manufacture. Each of these sets of approaches can make a key contribution to the total savings that are possible. Complementary use of energy and exergy metrics illustrates the way in which energy use might change and for the first time provides indication that in most cases other energy efficiency measures are unlikely to be adversely affected by the circular economy approaches. Potential for savings in the energy embodied in each key product input to each major sector is assessed, enabling prioritization of the areas in which the circular economy approaches have the greatest scope for impact and identification of supply chains for which they are underrepresented
Thermodynamic insights and assessment of the ‘circular economy’
This study analyses the effect on energy use of applying a wide range of circular economy approaches. By collating evidence on specific quantifiable approaches and then calculating and analyzing their combined full supply chain impacts through input-output analysis, it provides a more complete assessment of the overall potential scope for energy savings that these approaches might deliver than provided elsewhere. Assessment is conducted globally, across the EU-27 and in the UK. Overall, the identified opportunities have the potential to save 6%–11% of energy used to support economic activity, worldwide and in the EU, and 5%–8% in the UK. Their potential is equivalent to the total scope for other industrial energy efficiency savings. The potential savings are further divided into those due to sets of approaches relating to food waste, steel production, other materials production, product refurbishment, vehicle provision, construction and other equipment manufacture. Each of these sets of approaches can make a key contribution to the total savings that are possible. Complementary use of energy and exergy metrics illustrates the way in which energy use might change and for the first time provides indication that in most cases other energy efficiency measures are unlikely to be adversely affected by the circular economy approaches. Potential for savings in the energy embodied in each key product input to each major sector is assessed, enabling prioritization of the areas in which the circular economy approaches have the greatest scope for impact and identification of supply chains for which they are underrepresented
Scleral Thickness in Human Eyes
Purpose: To obtain information about scleral thickness in different ocular regions and its associations. Methods: The histomorphometric study included 238 human globes which had been enucleated because of choroidal melanomas or due to secondary angle-closure glaucoma. Using light microscopy, anterior-posterior pupil-optic nerve sections were measured. Results: In the non-axially elongated group (axial length #26 mm), scleral thickness decreased from the limbus (0.5060.11 mm) to the ora serrata (0.4360.14 mm) and the equator (0.4260.15 mm), and then increased to the midpoint between posterior pole and equator (0.6560.15 mm) and to the posterior pole (0.9460.18 mm), from where it decreased to the peri-optic nerve region (0.8660.21 mm) and finally the peripapillary scleral flange (0.3960.09 mm). Scleral thickness was significantly lower in the axially elongated group (axial length.26 mm) than in the non-axially elongated group for measurements taken at and posterior to the equator. Scleral thickness measurements of the posterior pole and of the peripapillary scleral flange were correlated with lamina cribrosa thickness measurements. Scleral thickness measurements at any location of examination were not significantly (all P.0.10) correlated with corneal thickness measurements. Scleral thickness was statistically independent of age, gender and presence of glaucoma. Conclusions: In non-axially elongated eyes, the sclera was thickest at the posterior pole, followed by the peri-optic nerv
A “spatially just” transition? A critical review of regional equity in decarbonisation pathways
Spatial justice is a theoretical framework that is increasingly used to examine questions of equity in the low carbon transition (LCT) from a geographical perspective. We conducted a semi-systematic review to define a ‘spatially just’ low carbon transition, considering how spatial dimensions are explicitly or implicitly presented in assessments of the LCT, and the policy and governance approaches that could embed spatial justice. A sample of 75 academic articles was thematically coded. Spatial justice involves the fair distribution of both benefits and burdens associated with LCTs, and this often creates problems of equity given the geographic gap between regions that ‘win and lose’. The studies point to a research gap in exploring fairness implications that go beyond the employment impacts of transition. Acceptance of the LCT is shown to be contingent on perceptions of justice, particularly whether the most responsible and capable actors are taking action. There is similar concern that the LCT may not address, or may reproduce, existing patterns of injustice. This is particularly the case in terms of spatially inequitable land uses and where historic planning policy has had lasting socioeconomic impacts. Policy challenges to making LCTs more spatially just included administrative fragmentation across spatial scales and the lack of coordination in net zero policy. We identify that future transition policymaking could benefit from using spatially targeted interventions, and in adopting a whole systems approach. In this recognition of the multiple economic vulnerabilities of different regions, LCT policymaking can become both more effective and, critically, more just
The impact of reducing car weight on global emissions: the future fleet in Great Britain
Current European policies define targets for future direct emissions of new car sales that foster a fast transition to electric drivetrain technologies. However, these targets do not consider the emissions produced in electricity generation and material production, and therefore fail to incentivise car manufacturers to consider the benefits of vehicle weight reduction. In this paper, we examine the potential benefits of limiting the average weight and altering the material composition of new cars in terms of global greenhouse gas emissions produced during the use phase, electricity generation and material production. We anticipate the emissions savings for the future car fleet in Great Britain until 2050 for various alternative futures, using a dynamic material flow analysis of ferrous metals and aluminium, and considering an evolving demand for car use. The results suggest that fostering vehicle weight reduction could produce greater cumulative emissions savings by 2050 than those obtained by incentivising a fast transition to electric drivetrains, unless there is an extreme decarbonization of the electricity grid. Savings promoted by weight reduction are immediate and do not depend on the pace of decarbonization of the electricity grid. Weight reduction may produce the greatest savings when mild steel in the car body is replaced with high-strength steel.
This article is part of the themed issue ‘Material demand reduction’.A.C.S. and J.M.A. were supported by EPSRC, grant reference no. EP/N02351X/1. J.B.N. was supported by EPSRC, grant reference no. EP/N022645/1
Virtual patients design and its effect on clinical reasoning and student experience : a protocol for a randomised factorial multi-centre study
Background
Virtual Patients (VPs) are web-based representations of realistic clinical cases. They are proposed as being an optimal method for teaching clinical reasoning skills. International standards exist which define precisely what constitutes a VP. There are multiple design possibilities for VPs, however there is little formal evidence to support individual design features. The purpose of this trial is to explore the effect of two different potentially important design features on clinical reasoning skills and the student experience. These are the branching case pathways (present or absent) and structured clinical reasoning feedback (present or absent).
Methods/Design
This is a multi-centre randomised 2x2 factorial design study evaluating two independent variables of VP design, branching (present or absent), and structured clinical reasoning feedback (present or absent).The study will be carried out in medical student volunteers in one year group from three university medical schools in the United Kingdom, Warwick, Keele and Birmingham. There are four core musculoskeletal topics. Each case can be designed in four different ways, equating to 16 VPs required for the research. Students will be randomised to four groups, completing the four VP topics in the same order, but with each group exposed to a different VP design sequentially. All students will be exposed to the four designs. Primary outcomes are performance for each case design in a standardized fifteen item clinical reasoning assessment, integrated into each VP, which is identical for each topic. Additionally a 15-item self-reported evaluation is completed for each VP, based on a widely used EViP tool. Student patterns of use of the VPs will be recorded.
In one centre, formative clinical and examination performance will be recorded, along with a self reported pre and post-intervention reasoning score, the DTI. Our power calculations indicate a sample size of 112 is required for both primary outcomes
The scale of population structure in Arabidopsis thaliana
The population structure of an organism reflects its evolutionary history and influences its evolutionary trajectory. It constrains the combination of genetic diversity and reveals patterns of past gene flow. Understanding it is a prerequisite for detecting genomic regions under selection, predicting the effect of population disturbances, or modeling gene flow. This paper examines the detailed global population structure of Arabidopsis thaliana. Using a set of 5,707 plants collected from around the globe and genotyped at 149 SNPs, we show that while A. thaliana as a species self-fertilizes 97% of the time, there is considerable variation among local groups. This level of outcrossing greatly limits observed heterozygosity but is sufficient to generate considerable local haplotypic diversity. We also find that in its native Eurasian range A. thaliana exhibits continuous isolation by distance at every geographic scale without natural breaks corresponding to classical notions of populations. By contrast, in North America, where it exists as an exotic species, A. thaliana exhibits little or no population structure at a continental scale but local isolation by distance that extends hundreds of km. This suggests a pattern for the development of isolation by distance that can establish itself shortly after an organism fills a new habitat range. It also raises questions about the general applicability of many standard population genetics models. Any model based on discrete clusters of interchangeable individuals will be an uneasy fit to organisms like A. thaliana which exhibit continuous isolation by distance on many scales
Paramedic clinical decision making during high acuity emergency calls: design and methodology of a Delphi study
<p>Abstract</p> <p>Background</p> <p>The scope of practice of paramedics in Canada has steadily evolved to include increasingly complex interventions in the prehospital setting, which likely have repercussions on clinical outcome and patient safety. Clinical decision making has been evaluated in several health professions, but there is a paucity of work in this area on paramedics. This study will utilize the Delphi technique to establish consensus on the most important instances of paramedic clinical decision making during high acuity emergency calls, as they relate to clinical outcome and patient safety.</p> <p>Methods and design</p> <p>Participants in this multi-round survey study will be paramedic leaders and emergency medical services medical directors/physicians from across Canada. In the first round, participants will identify instances of clinical decision making they feel are important for patient outcome and safety. On the second round, the panel will rank each instance of clinical decision making in terms of its importance. On the third and potentially fourth round, participants will have the opportunity to revise the ranking they assigned to each instance of clinical decision making. Consensus will be considered achieved for the most important instances if 80% of the panel ranks it as important or extremely important. The most important instances of clinical decision making will be plotted on a process analysis map.</p> <p>Discussion</p> <p>The process analysis map that results from this Delphi study will enable the gaps in research, knowledge and practice to be identified.</p
Preoperative computed tomography staging of nonmetastatic colon cancer predicts outcome: implications for clinical trials
Colon cancer patients routinely undergo preoperative computed tomography (CT) scanning, but local staging is thought to be inaccurate. We aimed to determine if clinical outcome could be predicted from radiological features of the primary tumour. Consecutive patients at one hospital undergoing primary resection for colon cancer during 2000–2004 were included. Patients with visible metastases were excluded. Preoperative CT scans were reviewed independently by two radiologists blinded to histological stage and outcome. Images of the primary tumour were evaluated according to conventional TNM criteria and patients were stratified into ‘good' or ‘poor' prognosis groups. Comparison was made between prognostic group and actual clinical outcome. Hundred and twenty-six preoperative CT scans were reviewed. T-stage and nodal status was correctly predicted in only 60 and 62%, respectively. However, inter-observer agreement for prognostic group was 79% (κ=0.59) and 3-year relapse-free survival was 71 and 43% for the CT-predicted ‘good' and ‘poor' groups, respectively (P<0.0066). This compared favourably with 75 vs 43% for histology-predicted prognostic groups. Computed tomography is a robust method for stratifying patients preoperatively, with similar accuracy to histopathology for predicting outcome. Recognition of poor prognosis tumours preoperatively may permit investigation into the future use of neo-adjuvant therapy in colon cancer
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