Studies on exploiting semiochemicals for pest management in organic farming systems OF0188

This study addresses the extent to which pest management systems can exploit semiochemicals (defined below) in ways acceptable to organic farming, and determines where the science base needs to be expanded to accommodate specific problems arising in an increasing organic farming sector. It considers whether current knowledge of semiochemical release from particular crop plants, herbs and wild plant species could be investigated further in relation to organic farming practice and identifies how strategies of multiple cropping, that exploit known semiochemical interactions, could be applied to key pest problems in organic production. Where such exploitation is not feasible, other strategies using semiochemicals including traps, extracts of natural products and nature-identical synthetic products are considered. Finally, general and specific directions in which research and development could facilitate greater penetration of the use of semiochemicals in crop protection for organic farming are identified. Semiochemicals are natural products that, by acting as signals, regulate interactions between organisms e.g. plants and insects. Once the semiochemical interactions between a pest and its host plant have been elucidated they can be exploited to regulate the pest population, providing an alternative control strategy to conventional toxicants. The choice of approach by which the semiochemicals are deployed relates to three options, i.e. from a natural plant source, from an extract or as a nature identical synthetic product. However, even where the most natural situations of mixed cropping are used, the scientific basis of the interaction must be established for robustness and sustainability of the approach. A complete understanding of the process allows a risk assessment to be made of any problems that might ensue when exploiting natural systems in different configurations from those encountered naturally. A major approach to using semiochemical based pest control is to exploit ways of repelling pests from crop plants and attracting them towards trap plantations. Deploying semiochemicals generated naturally by plants is consistent with organic farming practice, where a range of mixed cropping techniques are employed already, which ‘unconsciously’ utilise semiochemical effects. Thus, the acceptance and use of systems exploiting aspects of semiochemical deployment demonstrate an emerging role in organic farming practices. However, as emphasised before, a comprehensive knowledge of the semiochemical interactions that underpin these techniques is vital if they are to be exploited fully. Other pest control approaches compatible with organic farming, such as encouragement of beneficial species and the use of reflective surfaces in mulches, may not involve semiochemical effects, but could be exploited more beneficially by integration with semiochemical practices. Semiochemicals generated naturally by plants can be used to influence beneficial organisms as well as invertebrate pests. For example, plant defence chemicals, induced by pest or pathogen infestation, can affect the behaviour of pests and their natural enemies. Semiochemicals can be employed to maximise the impact of parasitic organisms that attack pest populations, for example in the management of refugia for maintaining and increasing populations of these beneficial organisms. In addition, the approach can be applied against other organisms antagonistic to agriculture besides invertebrate pests, for example in weed control, where signals interfering with weed germination can be exploited. Extracts of natural products provide semiochemicals in a form that is familiar and acceptable to organic farming practice, where plant extracts are already used as toxicants or as semiochemical antifeedants and repellents. However, often the scientific basis for use of these materials is limited, and therefore, exploitation is also limited and can be unreliable. By understanding the composition and the mechanism of activity of semiochemicals, natural product extracts can be improved by selection of the best sources of natural materials and appropriate processes of extraction and formulation. Many natural products, particularly pheromones (semiochemicals acting between members of the same species), can be synthesised as nature-identical and the synthetic forms are often indistinguishable from the natural form. Synthesis can be expensive, but where possible, starting materials should be obtained from natural renewable resources. Nature-identical synthetic pheromones are used widely in parts of the world, either deployed in traps for monitoring, mass trapping and lure and kill strategies or for direct pest control approaches such as mating disruption. In addition, manipulation of beneficial species with pheromones is being investigated and synthetic food-related attractants and oviposition attractants have also been developed for pests where pheromones are not available. Already some nature-identical synthetic semiochemicals have been accepted as compatible with organic farming practice. The registration of many sex and aggregation pheromones has been possible because they are nature-identical and are deployed away from the crop or on crop areas that are not consumed. In most cases, semiochemicals, deployed alone, are not sufficiently robust to control pest populations directly. They are most effective when incorporated into strategies, such as the ‘push-pull’ strategy, that are integrated with other forms of pest control, e.g. pathogens, parasitoids and predators, mechanical barriers and resistant plant varieties. The integration of semiochemical approaches with other methods of pest population reduction will help prevent the development of pest resistance to the overall strategy. Since the integrated strategy comprises a number of components that affect different aspects of pest behaviour and development each component can be relatively ineffective when compared to conventional pesticides. However, this has the advantage of not selecting efficiently for resistance to any component of the strategy and thus contributes to the sustainability of the approach. Recommendations 1) Develop a priority list of specific and general problems in organic production to be targeted by semiochemical methodologies in addition to known problems such as in carrot and lettuce production, aphids on a range of vegetable crops and for fruit pests. 2) Develop semiochemical based control methods suitable for 1) and for the targets already known. 3) Provide scientific input, where lacking, for 1 and 2. 4) Encourage greater diversification in organic cropping systems, including agroforestry, so as to exploit current knowledge of semiochemical based control and to pave the way for new interventions as the science develops. 5) Consider semiochemical attributes of non-crop plant inputs including mulches, weeds and multifunctional beneficial plants and the roles that they might play in organic systems. 6) Initiate organic plant breeding programmes, specifically to exploit natural semiochemical release where understood, for crop and companion plants

Modelling emergency response communication systems

Subsequent to the Australian \u27Black Saturday\u27 bushfires there were a number of issues arising from investigations with regard to the functional stability and resilience of communications systems and the flow of information between emergency response organisations, and their ability to provide relevant information to the general public. In some cases, the transference of information failed or was late or ineffective with regard to decisions, advice and information broadcasting during the crisis. This was particularly evident in terms of managing emergency organisational information requests and field situational advice both to and from emergency response management teams and the delivery of informative advice to the public. This paper analyses one such case study with a view of applying a systems modelling technique to determine the viability of the communication systems and information exchange structures associated with an emergency response agency

A Survey of Health and Safety Practice in the Agricultural Sector of New Zealand

Available OA via ResearchGate and Academi

Enhancement of methyl-aminolevulinate photodynamic therapy by iron chelation with CP94: an in vitro investigation and clinical dose-escalating safety study for the treatment of nodular basal cell carcinoma.

Clinical TrialAuthor version of article. The final publication is available at Springer via: http://dx.doi.org/10.1007/s00432-008-0358-6PURPOSE: Methyl-aminolevulinate (MAL) photodynamic therapy (PDT) is a cancer therapy that combines the selective accumulation of a photosensitizer in tumor tissue with visible light (and tissue oxygen) to produce reactive oxygen species. This results in cellular damage and ablation of tumor tissue. Combining iron chelators with MAL has the potential to increase the accumulation of the photosensitizer protoporphyrin IX (PpIX) by reducing its bioconversion to heme. This paper investigates this method of enhancement both in vitro and for the first time clinically for the treatment of nodular basal cell carcinoma (BCC). METHODS: Enhancement of MAL-induced PpIX accumulation by the iron chelator CP94 was quantified fluorometrically in human cultured cells (including three dermatological cell types). An open, dose-escalating, pilot study was then conducted in patients with nodular BCC, to determine the safety of this pharmacological modification. RESULTS: Large enhancements in PpIX accumulation were observed in the cultured cells when co-incubated with the iron chelator CP94. Clinically the addition of CP94 was found to be feasible and safe. In addition greater reductions in tumor depth were observed in the CP94 co-incubated tumors. CONCLUSION: Iron chelation by CP94 is an effective enhancer of MAL-induced PpIX accumulation in vitro. This method of enhancement was safely applied to a clinical PDT protocol with no unexpected adverse effects reported. Although the clinical investigation was only intended to be a small pilot to assess safety, enhancements in tumor clearance were observed both clinically and histologically when CP94 was included in the photosensitizing cream.Duchy Health Charity Limite

Coping with Congenital Heart Disease: Implementation of an Evidence-Based Intervention in a Pediatric Cardiac Intensive Care Unit

Caregivers are exposed to many stressors in the pediatric cardiac intensive care unit (CICU) setting. In caregivers of children diagnosed with congenital heart defects admitted to the CICU, symptoms of psychological distress are prevalent (Doherty et al., 2009). These symptoms include, but are not limited to, feelings of acute and chronic stress, worry, anxiety, and depression. Without intervention, these symptoms can negatively influence the health and behavioral outcomes of the admitted child (Commodari, 2010). Providing support for these caregivers during their child’s admission can reduce the significance of these adverse psychological symptoms and promote both patient and caregiver well-being (Melnyk et al., 2007). The purpose of this evidence-based practice project was to implement a coping intervention for caregivers of children admitted to the pediatric CICU. The Model for Evidence-Based Practice Change, combined with phases from Lippitt’s Theory of Planned Change, guided this project’s development, implementation, evaluation, and dissemination (Larrabbee, 2009; Lippitt, 1958). Eight caregivers of surgical infants in a single center pediatric CICU were provided a palliative care team intervention preoperatively and postoperatively. The aim was to help caregivers cope with common stressors in the CICU setting. Caregivers rated how stressful specific experiences in the pediatric CICU were to them by completing a modified version of the Parental Stressor Scale (PSS:NICU-16). Mean scores were evaluated before and after providing the caregivers with the palliative care team coping intervention. No statistically significant differences were found from baseline to after the palliative care intervention across three subscales (p= .375, .084, .443). However, there were reductions in the mean scores for stressors related to how their baby looked and behaved and stressors involving the parent relationship with their baby, suggesting clinical significance. Interventions that support caregivers’ mental health during their infant’s hospitalization can improve patient recovery and resilience. Palliative care teams have beneficial knowledge and skills that make them resourceful in promoting caregiver coping. Implementing a palliative care team intervention in the pediatric CICU setting for caregivers of patients receiving cardiac surgery may improve caregiver coping mechanisms and thereby promote patient healing and recovery

Hydrobiidae on North Uist

One of the problems of working on lochs that are slightly saline is a group of tiny (1-4mm) molluscs called mudsnails (Hydrobiidae). The rarest of these, Hydrobia acuta neglecta, was first identified in the UK in the Uists. This project aimed to eliminate any doubt about the identity. Genetic analyses funded by SNH and conducted by scientists at the National Museum of Scotland and Heriot-Watt University confirmed that there were healthy populations of this snail in three lochs in North Uist

ECONOMICALLY OPTIMAL WILDFIRE INTERVENTION REGIMES

Wildfires in the United States result in total damages and costs that are likely to exceed billions of dollars annually. Land managers and policy makers propose higher rates of prescribed burning and other kinds of vegetation management to reduce amounts of wildfire and the risks of catastrophic losses. A wildfire public welfare maximization function, using a wildfire production function estimated using a time series model of a panel of Florida counties, is employed to simulate the publicly optimal level of prescribed burning in an example county in Florida (Volusia). Evaluation of the production function reveals that prescribed fire is not associated with reduced catastrophic wildfire risks in Volusia County Florida, indicating a short-run elasticity of -0.16 and a long-run elasticity of wildfire with respect to prescribed fire of -0.07. Stochastic dominance is used to evaluate the optimal amount of prescribed fire most likely to maximize a measure of public welfare. Results of that analysis reveal that the optimal amount of annual prescribed fire is about 3 percent (9,000 acres/year) of the total forest area, which is very close to the actual average amount of prescribed burning (12,700 acres/year) between 1994-99.Resource /Energy Economics and Policy,