Increasing profits and reducing risks in crop production using participatory systems simulation approaches

The development of cropping systems simulation capabilities world-wide combined with easy access to powerful computing has resulted in a plethora of agricultural models and consequently, model applications. Nonetheless, the scientific credibility of such applications and their relevance to farming practice is still being questioned. Our objective in this paper is to highlight some of the model applications from which benefits for farmers were or could be obtained via changed agricultural practice or policy. Changed on-farm practice due to the direct contribution of modelling, while keenly sought after, may in some cases be less achievable than a contribution via agricultural policies. This paper is intended to give some guidance for future model applications. It is not a comprehensive review of model applications, nor is it intended to discuss modelling in the context of social science or extension policy. Rather, we take snapshots around the globe to 'take stock' and to demonstrate that well-defined financial and environmental benefits can be obtained on-farm from the use of models. We highlight the importance of 'relevance' and hence the importance of true partnerships between all stakeholders (farmer, scientists, advisers) for the successful development and adoption of simulation approaches. Specifically, we address some key points that are essential for successful model applications such as: (1) issues to be addressed must be neither trivial nor obvious; (2) a modelling approach must reduce complexity rather than proliferate choices in order to aid the decision-making process (3) the cropping systems must be sufficiently flexible to allow management interventions based on insights gained from models. The pro and cons of normative approaches (e.g. decision support software that can reach a wide audience quickly but are often poorly contextualized for any individual client) versus model applications within the context of an individual client's situation will also be discussed. We suggest that a tandem approach is necessary whereby the latter is used in the early stages of model application for confidence building amongst client groups. This paper focuses on five specific regions that differ fundamentally in terms of environment and socio-economic structure and hence in their requirements for successful model applications. Specifically, we will give examples from Australia and South America (high climatic variability, large areas, low input, technologically advanced); Africa (high climatic variability, small areas, low input, subsistence agriculture); India (high climatic variability, small areas, medium level inputs, technologically progressing; and Europe (relatively low climatic variability, small areas, high input, technologically advanced). The contrast between Australia and Europe will further demonstrate how successful model applications are strongly influenced by the policy framework within which producers operate. We suggest that this might eventually lead to better adoption of fully integrated systems approaches and result in the development of resilient farming systems that are in tune with current climatic conditions and are adaptable to biophysical and socioeconomic variability and change. (C) 2001 Elsevier Science Ltd. All rights reserved.

Economic Instruments and Regulatory Approaches in Implementing Riparian Revegetation Options: Observations of the Queensland System

Riparian vegetation can be an effective measure for preventing degradation of streambanks and riparian areas. However, riparian revegetation imposes large costs on landholders associated with tree establishment and removal of land from cropping, while providing benefits to downstream landholders, fishers, the local community and environmentalists. Appropriate policy instruments are required to promote sustainable and balanced use of riparian zones. This article analyses the capacity of existing legislation and other instruments to promote restoration of degraded riparian zones on private land. The role of legislation. economic instruments, community engagement and extension programs, in persuading landholders to revegetate riparian areas and improve riparian vegetation cover; is examined in the context ofa small degraded catchment in an intensive farming area in tropical north Queensland. It is found that while legislation and regulations can control undesirable modification of riparian areas, in general they are unable to make a useful contribution to restoration of these areas; incentives and assistance measures appear to offer greater potential.

Surgical extraction of transplanted adult Dirofilaria immitis in cats

A jugular venotomy technique was developed to attempt extraction of Dirofilaria immitis in cats. Seven cats were first examined by cardiac ultrasound to establish the location of adult D. immitis that had been inserted by jugular venotomy. The efficiency of an extractor catheter in surgically removing filariae similarly inserted into 13 experimental cats was then assessed. A mean extraction success rate of 96% was achieved. This technique would seem to be worthy of clinical use provided the filariae are in the right atrial area.

Shoulder movement after breast cancer surgery: results of a randomised controlled study of postoperative physiotherapy

Breast screening programmes have facilitated more conservative approaches to the surgical and radiotherapy management of women diagnosed with breast cancer. This study investigated changes in shoulder movement after surgery for primary, operable breast cancer to determine the effect of elective physiotherapy intervention. Sixty-five women were randomly assigned to either the treatment (TG) or control group (CG) and assessments were completed preoperatively, at day 5 and at 1 month, 3, 6, 12 and 24 months postoperatively. The CG only received an exercise instruction booklet in comparison to the TG who received the Physiotherapy Management Care Plan (PMCP). Analyses of variance revealed that abduction returned to preoperative levels more quickly in the TG than in the CG. The TG women had 14degrees more abduction at 3 months and 7degrees at 24 months. Functional recovery at 1 month was greater in those randomised to the TG, with a dominant operated arm (OA) or receiving breast-conserving surgery. However, it was not possible to predict recovery over the 2 years postoperatively on the basis of an individual woman's recovery at 1 month postoperatively. The eventual recovery of abduction or flexion range of movement was not related to the dominance of the OA nor to the surgical procedure performed. The PMCP provided in the early postoperative period is effective in facilitating and maintaining the recovery of shoulder movement over the first 2 years after breast cancer surgery.

The rhetoric of sector-wide approaches for health development

The past decade has witnessed an increasing concerns over the effectiveness of project-based development assistance and the promotion of sector-wide approaches (SWAps) to health as a means to increase donor collaboration, consolidate local management of resources and undertake the policy and systems reform necessary to achieve a greater impact on health issues. The concept has gained the support of both the World Bank and the World Health Organisation, as well as key bilateral donors, and dominates current initiatives in development assistance for health. This paper examines the proposal of SWAps as rhetoric, and seeks to understand how that rhetoric functions, despite the variable application of its constituent elements and the range of contexts in which it operates. (C) 2002 Elsevier Science Ltd. All rights reserved.

Porous solids from layered clays by combined pillaring and templating approaches

The pore structure formation in bentonite, pillared with a mixed sol of silicon and titanium hydroxides and treated subsequently with quaternary ammonium surfactants, is investigated. The surfactant micelles act as a template, similar to their role in MCM41 synthesis. Because both the surfactant micelles and the sol particles are positively charged, it is greatly favorable for them to form meso-phase assembles in the galleries between the clay layers that bear negative charges. Besides, the sol particles do not bond the clay layers strongly as other kinds of pillar precursors do, so that the treatment with surfactants can result in radical structure changes in sol-pillared clays. This allows us to tailor the pore structure of these porous clays by choice of surfactant. The surfactant treatment also results in profound increases in porosity and improvement in thermal stability. Therefore, the product porous clays have great potential to be Used to deal with large molecules or at high operating temperatures. We also found that titanium in these samples is highly dispersed in the silica matrix rather than existing in the form of small particles of pure titania. Such highly dispersed Ti active centers may offer excellent activities for catalytic oxidation reactions such as alkanes into alcohols and ketones.

Post-discharge surveillance: can patients reliably diagnose surgical wound infections?

Post-discharge surgical wound infection surveillance is an important part of many infection control programs. It is frequently undertaken by patient self-assessment, prompted either by a telephone or postal questionnaire. To assess the reliability of this method, 290 patients were followed for six weeks post-operatively. Their wounds were photographed and also covertly assessed for signs of infection by two experienced infection control nurses (ICNs). Patients also responded to a postal questionnaire seeking evidence of infection at both week four and week six post-surgery. Correlation between the patient's assessment of their wound and the ICNs diagnosis was poor (r = 0. 37) with a low positive predictive value (28.7%), although negative predictive value was high (98.2%). Assessment of photos for signs of infection by two experienced clinicians also correlated poorly with the ICNs diagnosis of infection (r = 0.54). The patient's recall of prescription of an antibiotic by their general practitioner (GP) for wound infection during the postoperative period correlated best with the ICNs diagnosis (r = 0.76). This latter measure, particularly when confirmed by the GP in those patients reporting an infection, appears to provide the most valid and resource efficient marker of post-discharge surgical wound infection.

Immunity to asexual blood stage malaria and vaccine approaches

The development of a malaria vaccine seems to be a definite possibility despite the fact that even individuals with a life time of endemic exposure do not develop sterile immunity. An effective malaria vaccine would be invaluable in preventing malaria-associated deaths in endemic areas, especially amongst children less than 5 years of age and pregnant women. This review discusses our current understanding of immunity against the asexual blood stage of malaria - the stage that is responsible for the symptoms of the disease - and approaches to the design of an asexual blood stage vaccine.

Surgical programme at Royal Alexandra Hospital, Sydney, for Papua New Guinea children with congenital heart disease, 1978-1994

Objective : To report the history of the Royal Alexandra Hospital for Children (RAHC) Papua New Guinea (PNG) cardiac surgical programme and describe the selection, preoperative clinical features and postoperative outcome of children with congenital heart disease managed by the programme. Methods : Details for each of the PNG cardiac patients admitted to RAHC following selection by visiting cardiologists between 1978 and 1994 were entered into a database, and analysed and interpreted. Results : A congenital heart defect was confirmed in 165 of the 170 children selected. The male to female ratio was 1:1 and the mean age on admission to RAHC was 5.5 years. Almost all of the children for whom data were available (98%) had a weight for age and 41% had a height for age less than the 3rd centile. One-sixth had delayed milestones. A large number were tachypnoeic, in heart failure, or had pulmonary hypertension on admission. Ventricular septal defect and tetralogy of Fallot were the commonest defects, and lesions such as aortic stenosis, coarctation of the aorta and transposition of the great arteries were absent or rare. Thirty-one (19%) of the children selected initially did not receive surgery because of pulmonary hypertension, or because the lesions did not fall within the programme guidelines for operation. One hundred and twenty-nine children had corrective and four had palliative procedures. Half of the operated children had postoperative complications. Eight children died, all following open-heart procedures, giving a case fatality rate of 6%. Preoperative tachypnoea, hepatomegaly, cardiac failure and pulmonary hypertension were strongly associated with poor outcome. Conclusions : The programme was an arduous exercise for all organizations concerned, but achieved comparatively good short-term outcomes. The experience gained should assist in planning for similar programmes.