The Role of Uncertainty in CO2 Emissions Inventories

We have greater certainty for what has happened in the past than for what will happen in the future. Uncertainty on the impact and value of emissions can be very large. Given all of the elements of uncertainty, we are challenged to set global targets for limiting the environmental impact of emissions, to distribute those targets among the many Parties responsible for emissions, to evaluate the trajectories toward targets, to understand the risk involved in not meeting targets, to motivate the collective efforts and burden sharing or trading, and to verify that targets have been achieved

Weighting for health : management, measurement and self-surveillance in the modern household

Histories of late nineteenth- and early twentieth-century medicine emphasise the rise of professional and scientific authority, and suggest a decline in domestic health initiatives. Exploring the example of weight management in Britain, we argue that domestic agency persisted and that new regimes of measurement and weighing were adapted to personal and familial preferences as they entered the household. Drawing on print sources and objects ranging from prescriptive literature to postcards and ‘personal weighing machines’, the article examines changing practices of self-management as cultural norms initially dictated by ideals of body shape and function gradually incorporated quantified targets. In the twentieth century, the domestic management of health—like the medical management of illness—was increasingly technologised and re-focused on quantitative indicators of ‘normal’ or ‘pathological’ embodiment. We ask: in relation to weight, how did quantification permeate the household, and what did this domestication of bodily surveillance mean to lay users

Histories of medicine in the household : recovering practice and ‘reception’

Introducing the essays in this special issue on medicine in the household, Bivins, Marland and Tomes briefly sketch the existing historiography and argue for the enduring importance of the household as a site of medical decision making and practice. The household as explored by this collection also offers a valuable space within which to test new methodologies addressing the challenges that face historians and other scholars seeking to trace the reception, adoption and adaptation of new knowledge, practices and products

Post-operative monitoring of intestinal tissue oxygenation using an implantable microfabricated oxygen sensor

Anastomotic leakage (AL) is a common and dangerous post-operative complication following intestinal resection, causing substantial morbidity and mortality. Ischaemia in the tissue surrounding the anastomosis is a major risk-factor for AL development. Continuous tissue oxygenation monitoring during the post-operative recovery period would provide early and accurate early identification of AL risk. We describe the construction and testing of a miniature implantable electrochemical oxygen sensor that addresses this need. It consisted of an array of platinum microelectrodes, microfabricated on a silicon substrate, with a poly(2-hydroxyethyl methacrylate) hydrogel membrane to protect the sensor surface. The sensor was encapsulated in a biocompatible package with a wired connection to external instrumentation. It gave a sensitive and highly linear response to variations in oxygen partial pressure in vitro, although over time its sensitivity was partially decreased by protein biofouling. Using a pre-clinical in vivo pig model, acute intestinal ischaemia was robustly and accurately detected by the sensor. Graded changes in tissue oxygenation were also measurable, with relative differences detected more accurately than absolute differences. Finally, we demonstrated its suitability for continuous monitoring of tissue oxygenation at a colorectal anastomosis over a period of at least 45 h. This study provides evidence to support the development and use of implantable electrochemical oxygen sensors for post-operative monitoring of anastomosis oxygenation

A new evaluation of the uncertainty associated with CDIAC estimates of fossil fuel carbon dioxide emission

Three uncertainty assessments associated with the global total of carbon dioxide emitted from fossil fuel use and cement production are presented. Each assessment has its own strengths and weaknesses and none give a full uncertainty assessment of the emission estimates. This approach grew out of the lack of independent measurements at the spatial and temporal scales of interest. Issues of dependent and independent data are considered as well as the temporal and spatial relationships of the data. The result is a multifaceted examination of the uncertainty associated with fossil fuel carbon dioxide emission estimates. The three assessments collectively give a range that spans from 1.0 to 13% (2 σ). Greatly simplifying the assessments give a global fossil fuel carbon dioxide uncertainty value of 8.4% (2 σ). In the largest context presented, the determination of fossil fuel emission uncertainty is important for a better understanding of the global carbon cycle and its implications for the physical, economic and political world

In vivo validation of a miniaturized electrochemical oxygen sensor for measuring intestinal oxygen tension

Recent advances in the fields of electronics and microfabrication techniques have led to the development of implantable medical devices for use within the field of precision medicine. Monitoring visceral surface tissue O2 tension (ptO2) by means of an implantable sensor is potentially useful in many clinical situations including the peri-operative management of patients undergoing intestinal resection and anastomosis. This concept could provide a means by which treatment could be tailored to individual patients. This study describes the in vivo validation of a novel miniaturised electrochemical O2 sensor to provide real-time data on intestinal ptO2. A single O2 sensor was placed onto the serosal surface of the small intestine of anaesthetised rats that were exposed to ischaemic (superior mesenteric artery occlusion) and hypoxaemic (alterations in inspired fractional O2 concentrations) insults. Control experiments demonstrated that the sensors function and remain stable in an in vivo environment. Intestinal ptO2 decreased following superior mesenteric artery occlusion and with reductions in inspired O2 concentrations. These results were reversible after reinstating blood flow or increasing inspired O2 concentrations. We have successfully developed an anaesthetised rat intestinal ischaemic and hypoxic model for validation of a miniaturised O2 sensor to provide real-time measurement of intestinal ptO2. Our results support further validation of the sensors in physiological conditions using a large animal model to provide evidence of their use in clinical applications where monitoring visceral surface tissue O2 tension is important

Implications of "peak oil" for atmospheric CO2 and climate

Unconstrained CO2 emission from fossil fuel burning has been the dominant cause of observed anthropogenic global warming. The amounts of "proven" and potential fossil fuel reserves are uncertain and debated. Regardless of the true values, society has flexibility in the degree to which it chooses to exploit these reserves, especially unconventional fossil fuels and those located in extreme or pristine environments. If conventional oil production peaks within the next few decades, it may have a large effect on future atmospheric CO2 and climate change, depending upon subsequent energy choices. Assuming that proven oil and gas reserves do not greatly exceed estimates of the Energy Information Administration, and recent trends are toward lower estimates, we show that it is feasible to keep atmospheric CO2 from exceeding about 450 ppm by 2100, provided that emissions from coal, unconventional fossil fuels, and land use are constrained. Coal-fired power plants without sequestration must be phased out before mid-century to achieve this CO2 limit. It is also important to "stretch" conventional oil reserves via energy conservation and efficiency, thus averting strong pressures to extract liquid fuels from coal or unconventional fossil fuels while clean technologies are being developed for the era "beyond fossil fuels". We argue that a rising price on carbon emissions is needed to discourage conversion of the vast fossil resources into usable reserves, and to keep CO2 beneath the 450 ppm ceiling.Comment: (22 pages, 7 figures; final version accepted by Global Biogeochemical Cycles