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Summary This model, which is an improved version of the model presented at the First International Symposium on Veterinary Epidemiology and Economics, at Reading in 1976, will attempt to demonstrate the potential benefits of linear programming. The model chose the most economically optimal solution for the control of brucellosis in beef cattle in the state of California. In addition to providing this optimal solution, the model also allows for sensitivity analyses to be performed on the various control components chosen by the model. It also permits a rapid benefit-cost analysis to be performed on other, less than economical, scenarios which may be chosen over the optimal solution. While not professed to be the ultimate solution, this model will provide a contrast to the many simulation models being used today in disease control program evaluation. The use of mathematical models and computers in epidemiology has been of importance for several years. In his examination of the development of the field of epidemiology, Dunn (1952) noted that, 'The accumulation of knowledge of epidemiological theory and the increasing use of statistical methods led progressively to a turn of epidemiology from a descriptive and comparative procedure to an analytic discipline. ' Further stressing the importance of mathematical development in epidemiology, Lilienfield (1973) stated: 'The mathematisation of biological or natural phenomena has considerable appeal to man in his effort to understand and control nature . . . it has led to increased precision in the thinking and defining of some ideas and concepts and frequently has been of assistance in the teaching of concepts . . For those who have had the opportunity to use or develop a model in an attempt to simulate the progression of a disease, the benefits of helping to understand the basic principles and impact of that disease are quite clear. To this individual, it is not a question of whether or not to use a computer model in his work, rather the question should be of the many models available, which is more suitable for my needs? In this paper we shall concern ourselves with the presentation of a particular type of model involving the mathematical technique of linear programming. As Piot (1966) stated: 'Mathematical programming and, under this general term, linear programming in particular, have been devised as techniques to find the optimal relationship between a number of interdependent variables, and as a means of determining the best course of action where such course may exist. It is in fact nothing more than putting explicitly what commonly goes on implicitly in the mind of decision makers

Economic Analysis of the 2016 California Drought on Agriculture: A report for the California Department of Food and Agriculture

UC Davis researchers forecast the socio-economic effects of the drought on California agriculture for 2014 and beyond. Economists use computer models and the latest estimates of water deliveries, well-pumping capacities and acres fallowed. The researchers exploit new satellite remote-sensing technologies to estimate fallowed acreage as the drought unfolds.UC Davis researchers forecast the socio-economic effects of the drought on California agriculture for 2014 and beyond. Economists use computer models and the latest estimates of water deliveries, well-pumping capacities and acres fallowed. The researchers exploit new satellite remote-sensing technologies to estimate fallowed acreage as the drought unfolds

Contextual factors among indiscriminate or larger attacks on food or water supplies, 1946-2015

This research updates previous inventories of malicious attacks on food and water to include data from 1946 through mid-2015. A systematic search of news reports, databases and previous inventories of poisoning events was undertaken. Incidents that threatened or were intended to achieve direct harm to humans, and that were either relatively large (number of victims > 4 or indiscriminate in intent or realisation were included. Agents could be chemical, biological or radio-nuclear. Reports of candidate incidents were subjected to systematic inclusion and exclusion criteria as well as validity analysis (not always clearly undertaken in previous inventories of such attacks). We summarise contextual aspects of the attacks that may be important for scenario prioritisation, modelling and defensive preparedness. Opportunity is key to most realised attacks, particularly access to dangerous agents. The most common motives and relative success rate in causing harm were very different between food and water attacks. The likelihood that people were made ill or died also varied by food/water mode, and according to motive and opportunity for delivery of the hazardous agent. Deaths and illness associated with attacks during food manufacture and prior to sale have been fewer than those in some other contexts. Valuable opportunities for food defence improvements are identified in other contexts, especially food prepared in private or community settings

HvALMT1 from barley is involved in the transport of organic anions

Members of the ALMT gene family contribute to the Al3+ resistance of several plant species by facilitating malate efflux from root cells. The first member of this family to be cloned and characterized, TaALMT1, is responsible for most of the natural variation of Al3+ resistance in wheat. The current study describes the isolation and characterization of HvALMT1, the barley gene with the greatest sequence similarity to TaALMT1. HvALMT1 is located on chromosome 2H which has not been associated with Al3+ resistance in barley. The relatively low levels of HvALMT1 expression detected in root and shoot tissues were independent of external aluminium or phosphorus supply. Transgenic barley plants transformed with the HvALMT1 promoter fused to the green fluorescent protein (GFP) indicated that expression of HvALMT1 was relatively high in stomatal guard cells and in root tissues containing expanding cells. GFP fused to the C-terminus of the full HvALMT1 protein localized to the plasma membrane and motile vesicles within the cytoplasm. HvALMT1 conferred both inward and outward currents when expressed in Xenopus laevis oocytes that were bathed in a range of anions including malate. Both malate uptake and efflux were confirmed in oocyte assays using [14C]malate as a radiotracer. It is suggested that HvALMT1 functions as an anion channel to facilitate organic anion transport in stomatal function and expanding cells

The structural properties of sexual fantasies for sexual offenders : a preliminary model

While the phenomenon of sexual fantasy has been researched extensively, little contemporary inquiry has investigated the structural properties of sexual fantasy within the context of sexual offending. In this study, a qualitative analysis was used to develop a descriptive model of the phenomena of sexual fantasy during the offence process. Twenty-four adult males convicted of sexual offences provided detailed retrospective descriptions of their thoughts, emotions and behaviours—before, during and after their offences. A data-driven approach to model development, known as Grounded Theory, was undertaken to analyse the interview transcripts. A model was developed to elucidate the structural properties of sexual fantasy in the process of sexual offending, as well as the physiological and psychological variables associated with it. The Sexual Fantasy Structural Properties Model (SFSPM) comprises eight categories that describe various properties of sexual fantasy across the offence process. These categories are: origin, context, trigger, perceptual modality, clarity, motion, intensity and emotion. The strengths of the SFSPM are discussed and its clinical implications are reviewed. Finally, the limitations of the study are presented and future research directions discussed

Improving communication between postgraduate researchers and the university library: a case study at De Montfort University Library and Learning Services

A well-established postgraduate researcher development program has existed at De Montfort University for many years. Library and Learning Services include modules on literature searching skills and critical appraisal. However, we recognized that researchers seemed to be disengaged with the services on offer. This concern informed a research project that considered the ways we could communicate better with researchers based on their needs. This paper explores the essential components of successful communication, such as context, timeliness and communication channels. An action-research approach was taken including focus groups and online surveys. The outcomes highlighted three significant crisis points, emphasizing the key times when researchers might need some intervention. The findings of this research identified the distinct needs of Postgraduate Researchers (PGRs) and how relevant and timely communication from the library can meet these needs. It also considers the impact of how communication has improved with researchers as a result of some of our interventions