Optimisation of Bacillus thuringiensis var. israelensis (Vectobac) applications for the blackfly control programme on the Orange River, South Africa

The Orange River, South Africa’s largest river, is a critical water resource for the country. In spite of the clear economic benefits of regulating river flows through a series of impoundments, one of the significant undesirable ecological consequences of this regulation has been the regular outbreaks of the pest blackfly species Simulium chutteri and S. damnosum s.l. (Diptera: Simuliidae). The current control programme, carried out by the South African National Department of Agriculture, uses regular applications, by helicopter, of the target-specific bacterial larvicide Bacillus thuringiensis var. israelensis. While cost-benefit analyses show significant benefits to the control programme, benefits could potentially be further increased through applying smaller volumes of larvicide in an optimised manner, which incorporates upstream residual amounts of pesticide through downstream carry. Using an optimisation technique applied in the West African Onchocerciasis Control Programme, to a 136 km stretch of the Orange River which includes 31 blackfly breeding sites, we demonstrate that 28.5% less larvicide could be used to potentially achieve the same control of blackfly. This translates into potential annual savings of between R540 000 and R1 800 000. A comparison of larvicide volumes estimated using traditional vs. optimised approaches at different discharges, illustrates that the savings on optimisation decline linearly with increasing flow volumes. Larvicide applications at the lowest discharge considered (40 m³·s^-1) showed the greatest benefits from optimisations, with benefits remaining but decreasing to a theoretical 30% up to median flows of 100 m3·s-1. Given that almost 70% of flows in July are less than 100 m³·s^-1, we suggest that an optimised approach is appropriate for the Orange River Blackfly Control Programme, particularly for flow volumes of less than 100 m³·s^-1. We recommend that trials be undertaken over two reaches of the Orange River, one using the traditional approach, and another using the optimised approach, to test the efficacy of using optimised volumes of B.t.i.

Prospective observational study of emergent endotracheal intubation practice in the intensive care unit and emergency department of an Australian regional tertiary hospital

Objective: The present study aimed to describe the characteristics and outcomes of intubation occurring in the ICU and ED of an Australian tertiary teaching hospital. Methods: This was a prospective observational study of intubation practice across the Geelong Hospital over a 6 month period from 1 August 2012 to 31 January 2013. Data were entered by the intubating team through an online data collection form. Results: There were 119 patients intubated and 134 attempts at intubation in the ED and ICU over a 6 month period. The first-pass success rate was 104/119 (87.4%), and all but a single patient was intubated by the second attempt. Propofol, fentanyl, midazolam and suxamethonium were the most common drugs used in rapid sequence induction. AEs were reported in 44/134 (32.8%) of intubation attempts, with transient hypoxia and hypotension being the most common. A significant adverse outcome, namely aspiration pneumonitis, occurred in one patient. There were no peri-intubation deaths. Conclusion: The majority of airways are managed by ICU and ED consultants and trainees, with success rates and AE rates comparable with other published studies. © 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Lifelong learning for farmers - the changing world of agriculture

Farmers must understand the intricacies of export markets, futures trading, share markets and global politics. Farmers are often living and working in isolated locations where the opportunities for professional development are limited. Yet they seem able to acquire knowledge and successfully apply it, with the result that agriculture is a growing and vigorous industry. In this paper I wish to acknowledge the unique learning environment of farmers by exploring their relationship with lifelong learning.

Assessing the economic benefits of starling detection and control to Western Australia

The common starling (Sturnus vulgaris) has a proven invasion history in many countries, and at a continental scale in North America and Australasia. In Australia, starlings are firmly established throughout the eastern states and Tasmania. Incursions of starlings into Western Australia (WA) represent a significant threat to this State’s agricultural, public amenity and biodiversity assets. We present models of starling population dynamics that incorporate environmental and control effort variability. We incorporate knowledge of starling ecology with economic data to assess the potential economic cost of starlings establishing in WA, evaluating the cost–benefits for each management scenario. We calculated starling population size will approach carrying capacity in WA within as little as 30 years if left unchecked. A population of this size could cost the WA economy up to $43.7 million annually in 2011/2012 dollars. Over a 50 year horizon, the conservative benefit–cost ratio for ongoing detection and control at the current level of expenditure is 6.03:1. However, even under current levels of control, starling numbers are projected to increase to almost 11 million by 2061. Further improvements in the efficiency of starling detection and control and/or an increased level of expenditure on detection and control are required.