AIR POLLUTION IMPACTS AND SOURCES UNDER A CHANGING CLIMATE: A CASE STUDY FOR SCUNTHORPE, UK

Climate change may affect local air quality by altering the emission, dispersion, chemical transformation and deposition of air pollutants. This study evaluates the effects of climate change in a real-life mixed land-use situation where there are adjacent urban and industrial activities and also fugitive emissions from stockpiles and unpaved roads. For this example we show how windspeed and time-of-day dependent ‘bi-polar plots’ created from ambient monitoring data can be used to learn more about the nature of sources responsible for exceedances of particulate matter air quality standards, and hence to assess how sensitive their impacts are to climate change. Unpaved roads and wind-blown fugitive sources such as stockpiles and coal handling beds in the industrial area appear to contribute substantially to raised air-quality impacts. The effect of climate change on impacts from these sources may differ from its effect on impacts from conventional combustion sources

Renewable energy scenarios:exploring technology, acceptance and climate – options at the community-scale

Community-based renewable energy could play a key role in the transition to a low carbon society. This paper argues that given the right environmental and societal conditions, communities in the UK could source a high percentage of their electricity supply from a mixture of localised renewable electricity technologies. Here we use exploratory scenarios to assess demand and renewable electricity supply-side options at the community-scale for a location in Cumbria, UK. Three scenarios are presented, using narratives of how local demand and renewable electricity supply could be constructed under either existing or modified environmental and societal conditions. The three scenarios explored were ‘Current State of Play’, ‘Low Carbon Adjusted Society’ and ‘Reluctant Scenario’

Advances in sensing ammonia from agricultural sources

Reducing ammonia emissions is one of the most difficult challenges for environmental regulators around the world. About 90% of ammonia in the atmosphere comes from agricultural sources, so that improving farm practices in order to reduce these emissions is a priority. Airborne ammonia is the key precursor for particulate matter (PM2.5) that impairs human health, and ammonia can contribute to excess nitrogen that causes eutrophication in water and biodiversity loss in plant ecosystems. Reductions in excess nitrogen (N) from ammonia are needed so that farms use N resources more efficiently and avoid unnecessary costs. To support the adoption of ammonia emission mitigation practices, new sensor developments are required to identify sources, individual contributions, to evaluate the effectiveness of controls, to monitor progress towards emission-reduction targets, and to develop incentives for behavioural change. There is specifically a need for sensitive, selective, robust and user-friendly sensors to monitor ammonia from livestock production and fertiliser application. Most currently-available sensors need specialists to set up, calibrate and maintain them, which creates issues with staffing and costs when monitoring large areas or when there is a need for high frequency sampling. This paper reports advances in monitoring airborne ammonia in agricultural areas. Selecting the right method of monitoring for each agricultural activity will provide critical data to identify and implement appropriate ammonia controls. Recent developments in chemo-resistive materials allow electrochemical sensing at room temperature, and new spectroscopic methods are sensitive enough to determine low concentrations in the order of parts per billion. However, these new methods still compromise selectivity and sensitivity due to the presence of ambient dust and other interferences, and are not yet suitable to be applied in agricultural monitoring. This review considers how ammonia measurements are made and applied, including the need for sensors that are suitable for routine monitoring by non-specialists. The review evaluates how monitoring information can be used for policies and regulations to mitigate ammonia emissions. The increasing concerns about ammonia emissions and the particular needs from the agriculture sector are addressed, giving an overview of the state-of-the-art and an outlook on future developments

2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011

Cold acclimation and freezing in Douglas-fir seedlings

Five major investigations were conducted on the cold hardiness of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings: (1) to define a hardiness measurement technique; (2) to determine environmental control and inducibility of hardiness at different parts of the first seasonal growth cycle; and (3) to examine the independence of acclimation, loss of hardiness and flushing in climatically "split" plants. Genetically identical material from hardy and nonhardy branches of the split plants was then used in conductometric and calorimetric studies of (4) the freezing process, and (5) the energy of tissue water, to see if adaptive changes in these could account for the induced hardiness differences. The measurement technique involved freezing samples of excised needles under controlled conditions to various temperatures, injury was estimated as the degree of browning after 7 days, and hardiness defined as the temperature causing 50% injury. Injury to excised needles was correlated with injury to attached needles, which was in turn broadly related to ultimate survival of whole plants frozen at the same temperature. Random error and possible bias in hardiness estimates both increased in hardier populations. Ten percent hardiness differences (e.g., two degrees in twenty) between populations could be detected with fifteen-plant samples; changes of 1°C could be followed during the course of treatment of an individual seedling. Controlled environment studies in the first growth cycle showed that germinants (1 week) were unable to attain any freezing tolerance under 8-hr days at 2°C even after 9 weeks, but were killed whenever ice formed. However, seedlings older than 3 weeks (1 to 2 cm of epicotyl) could develop true hardiness under the influence of either short days (less effective) or low temperatures (above 0°C), independently of lignification, bud setting or entry into rest. Ability to acclimate increased gradually with age, and was inversely related to growth and maturation, apparently because the latter processes had higher temperature optima. Photoperiod affected growth and bud formation only above about 15°C, but influenced hardiness at 1°C with a longer inductive daylength at low than at high light intensities (12 and 8 hours respectively). Interruption of the long inductive dark period with 15 min of red light (650 nm) caused a decrease in hardiness and bud set, and an increase in growth. Far-red interruptions (750 nm) alone had no effect, but enhanced the red light effect when applied immediately afterwards. Night frosts (-7°C) caused significant dehydration, and rapidly increased hardiness, only if both the warm short-day, and chilling treatments had been given in sequence first, and the daily supply of light continued. These results are in general agreement with the hypothesis that cold acclimation takes place in three physiologically distinct stages under natural conditions. Studies on 3-year-old seedlings were carried out by exposing each branch of a forked plant to a different temperature (2° or 20°C) but similar light conditions for periods of one to five months. The chilling stimulus for breaking rest and inducing hardiness was confined to the chilled branch, but the warm branch apparently transmitted a factor which prevented full hardening in the chilled one. A factor moving in the same direction also promoted flushing in branches chilled only at night from December to June (and receiving greenhouse temperatures and natural photoperiods by day). This was not replaceable by a single injection of gibberellic acid. Factors from the expanding shoot caused loss of short-day-induced hardiness in previous year's foliage and stimulated cambial division. Chilling at night prevented the dehardening but did not prevent cambial activity. The dehardening factor was translocated to an opposite branch whereas movement of cambium stimulator was strictly basipetal. These results suggest that promoter-inhibitor levels controlling dormancy are independently regulated, and that a two-stage dehardening process might protect against premature loss of hardiness in nature. The progress of freezing in needles of the hardy/nonhardy branch pairs was recorded simultaneously by differential thermal analysis and the conductance of low voltage direct electric current. The results of both methods exhibited the same major patterns. Freezing in immature leaves was nonequilibrium and intracellular. Freezing in needles cold-acclimated under short days was an equilibrium process preceded by a short non-equilibrium freezing of the free intercellular water fraction. This pattern did not change in leaves more deeply cold-acclimated by low temperatures. Thawing in mature needles was characterized by a greater proportion of ice (than during freezing) at all temperatures, with indications that not all the original cell water was reabsorbed. Freezing records are interpreted as showing that the cell membrane became more permeable to ions after injurious slow freezing but retained its essential integrity, whereas rapid freezing caused immediate membrane damage. No features of the freezing or thawing curves of first or subsequent freeze-thaw cycles were useful as predictors of injury to needles by slow freezing. Energy of water in hardy/nonhardy needle pairs was compared by two methods. Heats of vapourization (Δ H[sub v]) of weighed increments of water, removed from excised needles under vacuum, were estimated from the calibrated vapourization endotherms recorded on a differential thermal analyser. In the second method, needle water contents were measured gravimetrically after equilibration with lithium chloride solutions of known desiccating energy. It was found that Δ H[sub v], a proposed measure of water binding near surfaces, increased as the proportion of water remaining in the leaf decreased. For each increment removed, Δ H[sub v] was significantly higher in hardy needles, notwithstanding various possible sources of error. Hardy needles also retained more water non-osmotically (than nonhardy needles) after equilibration with LiCl isopeistic with their frost-killing temperature. The date suggest that avoidance of dehydration, principally by non-osmotic lowering of cell water potential, can account for almost half of the 25 centigrade degree difference in hardiness between branches.Forestry, Faculty ofGraduat

Calibrated digital images of Campbell–Stokes recorder card archives for direct solar irradiance studies

A systematic, semi-automatic method for imaging the cards from the widely used Campbell–Stokes sunshine recorder is described. We show how the application of inexpensive commercial equipment and practices can simply and robustly build an archive of high-quality card images and manipulate them into a form suitable for easy further analysis. Rectified and registered digital images are produced, with the card's midday marker in the middle of the longest side, and with a temporal scaling of 150 pixels per hour. The method improves on previous, mostly manual, analyses by simplifying and automating steps into a process capable of handling thousands of cards in a practical timescale. A prototype method of extraction of data from this archive is then tested by comparison with records from a co-located pyrheliometer at a resolution of the order of minutes. The comparison demonstrates that the Campbell–Stokes recorder archive contains a time series of downwelling solar-irradiance-related data with similar characteristics to that of benchmark pyrheliometer data from the Baseline Surface Radiation Network. A universal transfer function for card burn to direct downwelling short-wave radiation is still some way off and is the subject of ongoing research. Until such time as a universal transfer function is available, specific functions for extracting data in particular circumstances offer a useful way forward. The new image-capture method offers a practical way to exploit the worldwide sets of long-term Campbell–Stokes recorder data to create a time series of solar irradiance and atmospheric aerosol loading metrics reaching back over 100 yr from the present day

Glacier fluctuations on South Georgia during the 1970s and early 1980s

South Georgia is a highly glacierized island with a range of glacier types including corrie, valley and tidewater ice bodies. Glaciologically, it occupies a strategic location between South America and the Antarctic Peninsula and is potentially an important locality for establishing glacier-climate relationships in the region. Baseline surveys of ice front positions and ice surface profiles have been repeated to determine recent changes in several glacier types. Corrie and small, land-based valley glaciers have continued to thin and recede during the period of study, following an advance during the 1930s. Their behaviour primarily reflects the effects of seasonal temperature variations in controlling net balances, and particularly the climatic warming since 1950. The larger valley and tidewater glaciers display a lagged response and in the 1970s were at their most advanced positions since the Little Ice Age of the 17–19th centuries. However, in the last few years they too have commenced to thin and recede

Towards smarter air quality analysis

This presentation describes the remit of a 3-year knowledge exchange project which aims to develop, disseminate and ultimately promote uptake of smarter forms of air quality analysis for more effective air quality management. Two "smarter" techniques are introduced then used to characterise modelled and monitored impacts of a large coal-fired power station on a down-wind monitor