Hunt W.,Northern Territory Government |
Birch C.,University of Tasmania |
Coutts J.,Coutts JandR Toowoomba |
Vanclay F.,University of Groningen
Journal of Agricultural Education and Extension | Year: 2012
Purpose: This article outlines the development of extension as a discipline in Australia, its organization, and the ideological changes that have occurred from the second half of the nineteenth century through to the present.Design/Methodology/Approach: It considers the evolution of extension across the different states of Australia from a national perspective and describes how the research development and extension (RD&E) complex has rotated through cycles of crises, highs, awakenings in thought and practice, and periods where achievements and institutions unravel.Findings: Discussed is the tension between public and private sector extension, as well as the successes and failures of various paradigms. It considers the impacts of different agricultural policy on Australian agricultural RD&E across the decades. In particular it deals with the current 'unravelling' of the agricultural RD&E system in Australia, and tries to anticipate future demands on agricultural extension and how these services might be delivered into the future.Practical Implications: The article challenges the reader to consider the discipline of extension as a subset of the greater society in which it exists. It provides an insight into how the agricultural research, development and extension capacity of a nation can be observed to ebb and flow over generations in accord with the rhythm of society.Originality/Value: The article presents a perspective that has not been fully captured or understood until now. © 2012 Copyright Wageningen University.
Turnbull C.,Macquarie University |
Hoggard S.,Macquarie University |
Gillings M.,Macquarie University |
Palmer C.,Northern Territory Government |
And 6 more authors.
Biology Letters | Year: 2011
We hypothesize that aggregations of animals are likely to attract pathogenic micro-organisms and that this is especially the case for semisocial and eusocial insects where selection ultimately led to group sizes in the thousands or even millions, attracting the epithet 'superorganism'. Here, we analyse antimicrobial strength, per individual, in eight thrips species (Insecta: Thysanoptera) that present increasing innate group sizes and show that species with the largest group size (100-700) had the strongest antimicrobials, those with smaller groups (10-80) had lower antimicrobial activity, while solitary species showed none. Species with large innate group sizes showed strong antimicrobial activity while the semisocial species showed no activity until group size increased sufficiently to make activity detectable. The eusocial species behaved in a similar way, with detectable activity appearing once group size exceeded 120. These analyses show that antimicrobial strength is determined by innate group size. This suggests that the evolution of sociality that, by definition, increases group size, may have had particular requirements for defences against microbial pathogens. Thus, increase in group size, accompanied by increased antibiotic strength, may have been a critical factor determining the 'point of no return', early in the evolution of social insects, beyond which the evolution of social anatomical and morphological traits was irreversible. Our data suggest that traits that increase group size in general are accompanied by increased antimicrobial strength and that this was critical for transitions from solitary to social and eusocial organization. © 2011 The Royal Society.
Bailie R.S.,Charles Darwin University |
McDonald E.L.,Charles Darwin University |
Stevens M.,Charles Darwin University |
Guthridge S.,Northern Territory Government |
Brewster D.R.,James Cook University
Journal of Epidemiology and Community Health | Year: 2011
Background and Aim: Housing programmes in indigenous Australian communities have focused largely on achieving good standards of infrastructure function. The impact of this approach was assessed on three potentially important housing-related influences on child health at the community level: (1) crowding, (2) the functional state of the house infrastructure and (3) the hygienic condition of the houses. Methods: A before-and-after study, including house infrastructure surveys and structured interviews with the main householder, was conducted in all homes of young children in 10 remote Australian indigenous communities. Results: Compared with baseline, follow-up surveys showed (1) a small non-significant decrease in the mean number of people per bedroom in the house on the night before the survey (3.4, 95% CI 3.1 to 3.6 at baseline vs 3.2, 95% CI 2.9 to 3.4 at follow-up; natural logarithm transformed t test, t=1.3, p=0.102); (2) a marginally significant overall improvement in infrastructure function scores (KruskaleWallis test, χ2=3.9, p=0.047); and (3) no clear overall improvement in hygiene (KruskaleWallis test, χ2=0.3, p=0.605). Conclusion Housing programmes of this scale that focus on the provision of infrastructure alone appear unlikely to lead to more hygienic general living environments, at least in this study context. A broader ecological approach to housing programmes delivered in these communities is needed if potential health benefits are to be maximised. This ecological approach would require a balanced programme of improving access to health hardware, hygiene promotion and creating a broader enabling environment in communities.
Smerdon B.D.,CSIRO |
Payton Gardner W.,CSIRO |
Payton Gardner W.,Sandia National Laboratories |
Harrington G.A.,CSIRO |
Tickell S.J.,Northern Territory Government
Journal of Hydrology | Year: 2012
A mixture of older regional-scale groundwater flow and relatively modern local-scale groundwater was identified as the source of baseflow to a perennial river in a tropical savanna. Multiple environmental tracers, including 222Rn, CFCs, SF 6, and 4He were measured in the river, groundwater, and springs along a 60km segment of the Daly River in the Northern Territory of Australia. At the location where a group of springs intersected the river, groundwater discharge contained elevated 4He and very low concentrations of CFCs and SF 6. This influx of regional-scale groundwater could be detected at downstream locations in the river and was used to parameterize a one-dimensional model for estimating the groundwater discharge flux. Upstream and downstream of the springs, the source of baseflow is composed of waters containing SF 6 and CFCs from local-scale groundwater sources adjacent to the river. Within 1km of the river, a redox fence was detected, with reducing conditions leading to degradation of CFCs that could have masked detecting the contribution of local-scale sources. This study confirmed the applicability of a new technique using 4He to identify regional-scale groundwater flow contributions to rivers, and demonstrated that multi-tracer studies are needed to identify the locations, rates, and sources of baseflow. © 2012.
Dickman C.R.,University of Sydney |
Palmer C.,Northern Territory Government |
Graham G.,Conservation Commission of Western Australia |
Partridge T.,Macquarie University
PLoS ONE | Year: 2014
We construct a state-and-transition model for mammals in tropical savannas in northern Australia to synthesize ecological knowledge and understand mammalian declines. We aimed to validate the existence of alternative mammal assemblage states similar to those in arid Australian grasslands, and to speculate on transition triggers. Based on the arid grassland model, we hypothesized that assemblages are partitioned across rainfall gradients and between substrates. We also predicted that assemblages typical of arid regions in boom periods would be prevalent in savannas with higher and more regular rainfall. Data from eight mammal surveys from the Kimberley region, Western Australia (1994 to 2011) were collated. Survey sites were partitioned across rainfall zones and habitats. Data allowed us to identify three assemblage states: State 0:- low numbers of mammals, State II:- dominated by omnivorous rodents and State III:- dominated by rodents and larger marsupials. Unlike arid grasslands, assemblage dominance by insectivorous dasyurids (State I) did not occur in savannas. Mammal assemblages were partitioned across rainfall zones and between substrates as predicted, but - unlike arid regions - were not related strongly to yearly rainfall. Mammal assemblage composition showed high regional stability, probably related to high annual rainfall and predictable wet season resource pulses. As a consequence, we speculate that perpetually booming assemblages in savannas allow top-down control of the ecosystem, with suppression of introduced cats by the dingo, the region's top predator. Under conditions of low or erratic productivity, imposed increasingly by intense fire regimes and introduced herbivore grazing, dingoes may not limit impacts of cats on native mammals. These interacting factors may explain contemporary declines of savanna mammals as well as historical declines in arid Australia. The cat-ecosystem productivity hypothesis raised here differs from the already-articulated cat-habitat structure hypothesis for mammal declines, and we suggest approaches for explicit testing of transition triggers for competing hypotheses. © 2014 Radford et al.