Stewart J.,Australian Department of Primary Industries and Fisheries
Fisheries Research | Year: 2011
Exploited reef-associated species in south-eastern Australia have evolved life-history strategies to ensure population persistence through periods that are unsuitable for recruitment. They are characterized by considerable potential longevity (20-50 years), sexual maturation at relatively young ages (2-4 years old) and variable recruitment patterns. The age compositions in landings of the major reef-associated species in this region were used to demonstrate that some species have been subjected to significant age-class truncation. Species with long histories of exploitation had age compositions with relatively few fish greater than 5 years old. It is suggested that the removal of older age classes from the most heavily exploited populations has lowered their resilience to environmental change and that remedial management action may be required to rebuild reserves of older individuals. It is argued that the management options that are most likely to succeed in achieving this objective for populations of offshore reef-associated species include reducing rates of exploitation to very low levels, protecting larger/older fish through regulated maximum length limits and/or changes to gear selectivity and no take marine protected areas. The most appropriate management options will depend on the life-history of the species being considered. © 2010 Elsevier B.V.
Powell J.E.,Queensland Institute of Medical Research |
Visscher P.M.,Queensland Institute of Medical Research |
Goddard M.E.,University of Melbourne |
Goddard M.E.,Australian Department of Primary Industries and Fisheries
Nature Reviews Genetics | Year: 2010
Identity by descent (IBD) is a fundamental concept in genetics and refers to alleles that are descended from a common ancestor in a base population. Identity by state (IBS) simply refers to alleles that are the same, irrespective of whether they are inherited from a recent ancestor. In modern applications, IBD relationships are estimated from genetic markers in individuals without any known relationship. This can lead to erroneous inference because a consistent base population is not used. We argue that the purpose of most IBD calculations is to predict IBS at unobserved loci. Recognizing this aim leads to better methods to estimating IBD with benefits in mapping genes, estimating genetic variance and predicting inbreeding depression. © 2010 Macmillan Publishers Limited. All rights reserved.
Wilkinson K.G.,Australian Department of Primary Industries and Fisheries
Biomass and Bioenergy | Year: 2011
This review examines the drivers behind the adoption of on-farm anaerobic digestion in Germany where there were more than 4000 plants operating in 2009. In Australia, only one plant is operating, at a piggery in the State of Victoria. Germany's generous feed-in-tariffs for renewable energy are typically given the credit for promoting investment in on-farm anaerobic digestion. But the particular biophysical and socio-economic character of farming in the country provided the fertile ground for these financial incentives to take root. Energy security has also been a major driver for the promotion of renewable energy in Germany since it imports over 60% of its energy needs. In contrast, Australia is a net energy exporter, exporting about two-thirds of its domestic energy. Although it has considerable potential for application in Australia, anaerobic digestion is unlikely to be widely adopted unless new incentives emerge to strongly encourage investment. Stronger Australian regulation of manures and effluent may serve as an incentive to a limited extent in the future. Yet the experience in Germany suggests that regulation on its own was not sufficient to encourage large numbers of farmers to invest in anaerobic digestion. Even with generous incentives from the German government, increasing construction costs and the rising cost of energy crops can put the financial viability of anaerobic digestion plants at risk. Unless improvements in efficiency are found and implemented, these pressures could lead to unsustainable rises in the cost of the incentive schemes that underpin the development of renewable energy technologies. © 2011.
Lee S.H.,Queensland Institute of Medical Research |
Wray N.R.,Queensland Institute of Medical Research |
Goddard M.E.,Australian Department of Primary Industries and Fisheries |
Goddard M.E.,University of Melbourne |
Visscher P.M.,Queensland Institute of Medical Research
American Journal of Human Genetics | Year: 2011
Genome-wide association studies are designed to discover SNPs that are associated with a complex trait. Employing strict significance thresholds when testing individual SNPs avoids false positives at the expense of increasing false negatives. Recently, we developed a method for quantitative traits that estimates the variation accounted for when fitting all SNPs simultaneously. Here we develop this method further for case-control studies. We use a linear mixed model for analysis of binary traits and transform the estimates to a liability scale by adjusting both for scale and for ascertainment of the case samples. We show by theory and simulation that the method is unbiased. We apply the method to data from the Wellcome Trust Case Control Consortium and show that a substantial proportion of variation in liability for Crohn disease, bipolar disorder, and type I diabetes is tagged by common SNPs. © 2011 The American Society of Human Genetics.
Levot G.W.,Australian Department of Primary Industries and Fisheries
Australian Veterinary Journal | Year: 2012
Objective: To investigate the cause of cyromazine failure to protect lambs from flystrike. Methods: Lucilia cuprina larvae from a Nimmitabel (New South Wales) population associated with failure of a cyromazine spray-on to protect lambs from flystrike were compared with larvae from a susceptible field strain and a reference susceptible laboratory strain in laboratory bioassays. Batches of neonate blowfly larvae were transferred onto homogenised bovine liver containing varying concentrations of cyromazine or dicyclanil and the numbers of larvae pupating and completing development were recorded. Results: Based on the ability of larvae to complete development on liver homogenate containing 1mg/kg cyromazine, the phenotypic frequency of resistance in the Nimmitabel population was estimated to be approximately 4%. Compared with a susceptible field strain, the Nimmitabel population was 3-fold more resistant to cyromazine and twice as resistant to dicyclanil at the LC95 level (lethal concentration killing 95% of larvae). In the laboratory, the Nimmitabel strain responded to sequential exposure of larvae to food containing cyromazine by becoming more resistant. Resistance to cyromazine was incompletely dominant, giving resistant larvae a survival advantage over susceptible types over a relatively narrow range of cyromazine concentrations. Conclusion: Cyromazine resistance was detected in a field population of L. cuprina. Low-level cross-resistance to dicyclanil was also confirmed. Until more is known about the resistance, the prudent recommendation to control flystrike by this blowfly population is topical treatment with ivermectin. © 2012 The Authors. Australian Veterinary Journal © 2012 Australian Veterinary Association.