Estimating time to detect time trends in continuous cropping

SUMMARY In long-term field trials comparing different sequences of crops and husbandry practices, the identification and understanding of trends in productivity over time is an important issue of sustainable crop production. This paper presents a statistical technique for the estimation of time trends in yield variables of a seasonal annual crop under continuous cropping. The estimation procedure incorporates the correlation structure, which is assumed to follow first-order autocorrelation in the errors that arise over time on the same plot. Because large differences in annual rainfall have a major effect on crop performance, rainfall has been allowed for in the estimation of the time trends. Expressions for the number of years (time) required to detect statistically significant time trends have been obtained. Illustrations are based on a 7-year data set of grain and straw yields from a trial in northern Syria. Although agronomic interpretation is not intended in this paper, the barley yield data indicated that a significant time trend can apparently be detected even in a suboptimal data set of 7 years' duration.     

Marketing the Damaged Self: The Construction of Identity in Advertisements Directed Towards People with HIV/AIDS

This paper explores the identities projected in advertisements directed towards HIV positive individuals and people with AIDS. Fifty such advertisements were collected from three popular American magazines for gay men over a period of seven months. Analysis of the ads reveals a paradoxical presentation of people with HIV/AIDS, which offers simultaneous conflicting images of hope and fear, power and weakness, innocence and guilt. An interactive sociolinguistic model through which this contradictory discourse might be understood is presented, drawing on Goffman's insights on stigma management and the presentation of the self in social interaction. Advertisements directed towards people with HIV/AIDS, it is suggested, present a contradictory discourse in which the advertisers are positioned as 'the wise', offering to mediate the conflicting identities of the stigmatized. The identity values enacted in this contradictory discourse are further measured against American conceptions of communication and the self as observed by Carbaugh and others. The possible consequences of these positionings on the roles made available to people with HIV/AIDS in the wider social context are discussed.     

‘We Can All Just Get on a Bus and Go’: Rethinking Independent Mobility in the Context of the Universal Provision of Free Bus Travel to Young Londoners

This paper uses qualitative data from interviews with 118 young Londoners (age 12–18) to examine how the universal provision of free bus travel has affected young people’s independent mobility. Drawing on Sen’s capabilities approach, we argue that free bus travel enhanced young Londoners’ capabilities to shape their daily mobility, both directly by increasing financial access and indirectly by facilitating the acquisition of the necessary skills, travelling companions and confidence. These capabilities in turn extended both opportunity freedoms (e.g. facilitating non-‘necessary’ recreational and social trips) and process freedoms (e.g. feeling more independent by decreasing reliance on parents). Moreover, the universal nature of the entitlement rendered buses a socially inclusive way for groups to travel and spend time together, thereby enhancing group-level capabilities. We believe this attention to individual and group capabilities for self-determination provides the basis for a broader and more child-centred view of independent mobility than the typical research focus upon travelling without an adult and acquiring parental permissions.     

Medical Negligence and Resource Allocation in the NHS

The recent growth in medical malpractice claims and in awards for damages has created concern both amongst doctors and health administrators. Steps which have been taken by the Review Body on Doctors’and Dentists’Remuneration and policy now advocated by the BMA suggest a movement away from the current system of negligence and towards a stricter no-fault system of liability. Under the current system, medical negligence occurs when doctors have not met the standards of treatment expected by reference to current professional standards. Under a no-fault system patients would be entitled to compensation for losses which arise from treatment, irrespective of whether negligence had occurred; although the implication is that the amounts of compensation would necessarily be limited. While there are reasons to believe that financial difficulties for doctors and pressures on NHS budgets may be ameliorated by a no-fault system, there are other criteria against which the current system of negligence should be judged. This article attempts to provide a framework within which a negligence system may be assessed. In particular, attention is drawn to the educative role of a negligence system and to the provision of information which may improve decisions on resource allocation. A critique of the current system of medical negligence in the UK suggests that a package of reforms to improve the system would be better than further movements towards non-market solutions.