Contribution of integrated farm management (IFM) to Defra objectives

A farming system comprises a complex of interrelated and interacting factors. Any study of an isolated part of the system will not provide adequate understanding of the behaviour of the entire system and interactions may be equally or more important than individual components. There is therefore a requirement for the development of integrated approaches and practices to help farming systems adapt to, eliminate or reduce the negative impacts of production on the environment. This must be achieved whilst maintaining the economic viability of the farm enterprise. Our analysis has confirmed that IFM techniques generally have far more beneficial than adverse effects on current Defra policy objectives. However, there are some notable ‘conflicts’ where a technique that has a large beneficial effect in one policy area has a large negative effect in another. Carbon footprinting is used to quantify the impact of some integrated farming practices

A Generalized Method of Undetermined Coefficients

The method of undetermined coefficients is used to solve constant coefficient nonhomogeneous differential equations whose forcing function is itself the solution of a homogeneous constant coefficient differential equation. In this paper, we show that the classical methods for tackling constant coefficient equations, including the method of undetermined coefficients, generalize to much wider class linear differential equations which, for example, include Cauchy-Euler type equations. This general method includes an explicit construction of the fundamental solution sets of such equations. We also briefly consider where this method can be applied by producing the most general second and third order differential equations that are polynomial in a first order differential operator. In addition, we provide a number of constant coefficient, Cauchy-Euler, and novel examples

An empirical study of electricity and gas demand drivers in large food retail buildings of a national organisation

AbstractFood retail buildings account for a measurable proportion of a country's energy consumption and resultant carbon emissions so energy-operating costs are key business considerations. Increased understanding of end-use energy demands in this sector can enable development of effective benchmarking systems to underpin energy management tools. This could aid identification and evaluation of interventions to reduce operational energy demand. Whilst there are a number of theoretical and semi-empirical benchmarking and thermal modelling tools that can be used for food retail building stocks, these do not readily account for the variance of technical and non-technical factors that can influence end-use demands.This paper discusses the various drivers of energy end-uses of typical UK food retail stores. It reports on an empirical study of one organisation's hypermarket stock to evaluate the influence of various factors on annual store electricity and gas demands. Multiple regression models are discussed in the context of the development and application of a methodology for estimating annual energy end-use demand in food retail buildings. The established models account for 75% of the variation in electricity demand, 50% of the variation in gas demand in stores without CHP and 77% of the variation in gas demand in stores with CHP

Book Reviews

Reviews of the following books: Lobstering and The Maine Coast by Kenneth R. Martin and Nathan R. Lipfert; Beothuk Bark Canoes: An Analysis and Comparative Study by Ingeborg C.L. Marshall; Records of Meduncook Plantation and Friendship Maine, 1763-1899 edited by Melville B. Cook

Outcomes of stenting after uncomplicated ureteroscopy: systematic review and meta-analysis.

Objective To investigate the potential beneficial and adverse effects of routine ureteric stent placement after ureteroscopy. Design Systematic review and meta-analysis of randomised controlled trials. Data sources Cochrane controlled trials register (2006 issue 2), Embase, and Medline (1966 to 31 March 2006), without language restrictions. Review methods We included all randomised controlled trials that reported various outcomes with or without stenting after ureteroscopy. Two reviewers independently extracted data and assessed quality. Meta-analyses used both fixed and random effects models with dichotomous data reported as relative risk and continuous data as a weighted mean difference with 95% confidence intervals. Results Nine randomised controlled trials (reporting 831 participants) were identified. The incidence of lower urinary tract symptoms was significantly higher in participants who had a stent inserted (relative risk 2.25, 95% confidence interval 1.14 to 4.43, for dysuria; 2.00, 1.11 to 3.62, for frequency or urgency) after ureteroscopy. There was no significant difference in postoperative requirement for analgesia, urinary tract infections, stone free rate, and ureteric strictures in the two groups. Because of marked heterogeneity, formal pooling of data was not possible for some outcomes such as flank pain. A pooled analysis showed a reduced likelihood of unplanned medical visits or admission to hospital in the group with stents (0.53, 0.17 to 1.60), although this difference was not significant. None of the trials reported on health related quality of life. Cost reported in three randomised controlled trials favoured the group without stents. The overall quality of trials was poor and reporting of outcomes inconsistent. Conclusions Patients with stents after ureteroscopy have significantly higher morbidity in the form of irritative lower urinary symptoms with no influence on stone free rate, rate of urinary tract infection, requirement for analgesia, or long term ureteric stricture formation. Because of the marked heterogeneity and poor quality of reporting of the included trials, the place of stenting in the managementof patients after uncomplicated ureteroscopy remains unclear.Peer reviewedPublisher PD

Local variations in spatial synchrony of influenza epidemics

Background: Understanding the mechanism of influenza spread across multiple geographic scales is not complete. While the mechanism of dissemination across regions and states of the United States has been described, understanding the determinants of dissemination between counties has not been elucidated. The paucity of high resolution spatial-temporal influenza incidence data to evaluate disease structure is often not available. Methodology and Findings: We report on the underlying relationship between the spread of influenza and human movement between counties of one state. Significant synchrony in the timing of epidemics exists across the entire state and decay with distance (regional correlation = 62%). Synchrony as a function of population size display evidence of hierarchical spread with more synchronized epidemics occurring among the most populated counties. A gravity model describing movement between two populations is a stronger predictor of influenza spread than adult movement to and from workplaces suggesting that non-routine and leisure travel drive local epidemics. Conclusions: These findings highlight the complex nature of influenza spread across multiple geographic scales. © 2012 Stark et al