University of Aberdeen

About: University of Aberdeen is a education organization based out in Aberdeen, United Kingdom. It is known for research contribution in the topics: Population & Health care. The organization has 21174 authors who have published 49962 publications receiving 2105479 citations. The organization is also known as: Aberdeen University.

Pharmacology of Cannabinoid Receptor Ligands

Abstract: Mammalian tissues contain at least two types of cannabinoid receptor, CB 1 and CB 2 , both coupled to G proteins. CB 1 receptors are expressed mainly by neurones of the central and peripheral nervous system whereas CB 2 receptors occur in certain non-neuronal tissues, particularly in immune cells. The existence of endogenous ligands for cannabinoid receptors has also been demonstrated. The discovery of this 'endogenous cannabinoid system' has been paralleled by a renewed interest in possible therapeutic applications of cannabinoids, for example in the management of pain and in the suppression of muscle spasticity/spasm associated with multiple sclerosis or spinal cord injury. It has also prompted the development of a range of novel cannabinoid receptor ligands, including several that show marked selectivity for CB 1 or CB 2 receptors. This review summarizes current knowledge about the in vitro pharmacological properties of important CB 1 and CB 2 receptor ligands. Particular attention is paid to the binding properties of these ligands, to the efficacies of cannabinoid receptor agonists, as determined using cyclic AMP or [ 35 S]GTPγS binding assays, and to selected examples of how these pharmacological properties can be influenced by chemical structure. The in vitro pharmacological properties of ligands that can potently and selectively oppose the actions of CB 1 or CB 2 receptor agonists are also described. When administered by themselves, some of these ligands produce effects in certain tissue preparations that are opposite in direction to those produced by cannabinoid receptor agonists and the possibility that the ligands producing such 'inverse cannabimimetic effects' are inverse agonists rather than pure antagonists is discussed.

Increase in asthma: a more toxic environment or a more susceptible population?

Abstract: Serial prevalence studies have shown that childhood asthma is becoming more common. In the UK two recent studies have found that the overall prevalence of episodic wheeze and of diagnosed asthma has doubled over the last two decades.'2 In these studies the prevalence of hay fever was also shown to have increased by a factor of three to four, while that of eczema had doubled. In children in New Zealand and Australia asthma prevalence has also doubled over the same period.34 The situation in adults is less clear, and data for the UK are not available, but most evidence from other countries suggests that a similar increase is occurring. Thus, although Yunginger et al; found no evidence of an increase in the incidence of asthma in the adult population of Rochester, Minnesota during the years 196483, analysis of data from conscripts to the Finnish and Swedish defence forces reveals a sixfold increase in asthma prevalence at call-up examinations between 1966 and 1989 in Finland,6 and a 47% increase between 1971 and 1981 in Sweden.7 In Busselton, Australia8 the prevalence of diagnosed asthma in adults aged 18-55 increased from 9% to 16 3% between 1981 and 1990, and in Manitoba, Canada, physician diagnosed asthma was found to be increasing in all age groups between 1980 and 1990.9 As well as changes over time, increases in the prevalence of asthma have also followed \"westernisation\" of a society'0 and migration from subsistence societies to economically developed countries.\" 12 It is generally agreed that the observed increase in the prevalence of asthma is not simply a consequence of improved diagnosis'3'4 or of diagnostic transfer.'5 A change in genetic susceptibility of the population to the development of asthma is unlikely in the time period over which the observed increase has occurred. A more probable explanation is that the increase is due to the effects of life in the industrialised world resulting in an increase in exposure to exogenous factors which may induce asthma, a reduction in host resistance, or a combination of both mechanisms. Among exogenous factors which have been implicated in the increase in asthma are outdoor pollutants, indoor pollutants, cigarette smoke, and allergen exposure. Factors altering host resistance have received less attention. It has been suggested recently that a similar increase in the prevalence of hay fever coincided with the industrial revolution of the 18th and 19th centuries,16 and it is not surprising that the attention of researchers should have focused on air pollution both outdoors and indoors as a potential cause of increased asthma prevalence. With regard to outdoor pollutants, there is no doubt that many of these including sulphur dioxide, ozone, sulphuric acid and oxides of nitrogen can induce bronchoconstriction in susceptible individuals in the laboratory setting.'7 There is epidemiological evidence from the USA'8 and from the UK'9 that increases in ambient photochemical oxidants may be associated with respiratory symptoms and increased bronchodilator use in asthmatic subjects. However, air pollution in general in the UK has lessened substantially since the smogs of the 1950s with reduced burning of coal in cities, and there has been a well documented fall in levels of smoke and sulphur dioxide. Ozone is primarily a rural pollutant and the limited evidence available suggests that urban levels have not altered since the early 1970s.20 There is some evidence of a rise in background levels of oxides of nitrogen in rural situations since the 1970s, but peak urban levels in cities do not appear to have risen.202' While these data over an adequate time and range of sites are sparse, there is no evidence of the significant rises in any pollutants that would have been necessary were they to have been responsible for the increase in asthma and hay fever. In support of this conclusion, no association between exposure to particulates, nitrogen dioxide, or sulphur dioxide and prevalence of asthma was found in the American six cities study,2223 nor in a more recent study24 which compared schoolchildren in the heavily polluted city of Leipzig and the cleaner city of Munich; there was significantly more hay fever and rhinitis in Munich children, while the prevalence of asthma and airway hyperreactivity did not differ significantly between the two populations. The major component of indoor air pollution is cigarette smoke and there is abundant evidence that exposure to the constituents of cigarette smoke in utero and in childhood can increase the risk of developing allergy and respiratory symptoms.25-30 Again, however, it is difficult to attribute the considerable increase in asthma to changes in parental smoking. In the UK there has been a decline in the Department of Environmental and Occupational Medicine A Seaton

Surgeons’ Non-technical Skills in the Operating Room: Reliability Testing of the NOTSS Behavior Rating System

Abstract: Previous research has shown that surgeons’ intraoperative non-technical skills are related to surgical outcomes. The aim of this study was to evaluate the reliability of the NOTSS (Non-technical Skills for Surgeons) behavior rating system. Based on task analysis, the system incorporates five categories of skills for safe surgical practice (Situation Awareness, Decision Making, Task Management, Communication & Teamwork, and Leadership). Consultant (attending) surgeons (n = 44) from five Scottish hospitals attended one of six experimental sessions and were trained to use the NOTSS system. They then used the system to rate consultant surgeons’ behaviors in six simulated operating room scenarios that were presented using video. Surgeons’ ratings of the behaviors demonstrated in each scenario were compared to expert ratings (“accuracy”), and assessed for inter-rater reliability and internal consistency. The NOTSS system had a consistent internal structure. Although raters had minimal training, rating “accuracy” for acceptable/unacceptable behavior was above 60% for all categories, with mean of 0.67 scale points difference from reference (expert) ratings (on 4-point scale). For inter-rater reliability, the mean values of within-group agreement (r wg) were acceptable for the categories Communication & Teamwork (.70), and Leadership (.72), but below a priori criteria for other categories. Intra-class correlation coefficients (ICC) indicated high agreement using average measures (values were .95–.99). With the requisite training, the prototype NOTSS system could be used reliably by surgeons to observe and rate surgeons’ behaviors. The instrument should now be tested for usability in the operating room.

The top 100 questions of importance to the future of global agriculture

Abstract: Despite a significant growth in food production over the past half-century, one of the most important challenges facing society today is how to feed an expected population of some nine billion by the middle of the 20th century. To meet the expected demand for food without significant increases in prices, it has been estimated that we need to produce 70-100 per cent more food, in light of the growing impacts of climate change, concerns over energy security, regional dietary shifts and the Millennium Development target of halving world poverty and hunger by 2015. The goal for the agricultural sector is no longer simply to maximize productivity, but to optimize across a far more complex landscape of production, rural development, environmental, social justice and food consumption outcomes. However, there remain significant challenges to developing national and international policies that support the wide emergence of more sustainable forms of land use and efficient agricultural production. The lack of information flow between scientists, practitioners and policy makers is known to exacerbate the difficulties, despite increased emphasis upon evidence-based policy. In this paper, we seek to improve dialogue and understanding between agricultural research and policy by identifying the 100 most important questions for global agriculture. These have been compiled using a horizon-scanning approach with leading experts and representatives of major agricultural organizations worldwide. The aim is to use sound scientific evidence to inform decision making and guide policy makers in the future direction of agricultural research priorities and policy support. If addressed, we anticipate that these questions will have a significant impact on global agricultural practices worldwide, while improving the synergy between agricultural policy, practice and research. This research forms part of the UK Government's Foresight Global Food and Farming Futures project.

Spatially Averaged Open-Channel Flow over Rough Bed

Abstract: In this paper it is suggested that the double-averaged (in temporal and in spatial domains) momentum equations should be used as a natural basis for the hydraulics of rough-bed open-channel flows, especially with small relative submergence. The relationships for the vertical distribution of the total stress for the simplest case of 2D, steady, uniform, spatially averaged flow over a rough bed with flat free surface are derived. These relationships explicitly include the form-induced stresses and form drag as components of the total stress. Using this approach, we define three types of rough-bed flows: (1) Flow with high relative submergence; (2) flow with small relative submergence; and (3) flow over a partially inundated rough bed. The relationships for the double-averaged velocity distribution and hydraulic resistance for all three flow types are derived and compared with measurements where possible. The double-averaged turbulent and form-induced intensities and stresses for the case of regular spherical-segment-type roughness show the dominant role of the double-averaged turbulence stresses and form drag in momentum transfer in the near-bed region.