899 resultados para Turtles -- Ecology -- Australia


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While aggregate level pay equity comparisons between Australia and the UK confirm expectations based on their different wage distributions and regulatory systems, observation of trends and occupational level analysis reveal additional complexity. Our analysis suggests the need for a multi-faceted approach to closing the average gender pay gap.

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Velocity and absorption tomograms are the two most common forms of presentation of radar tomographic data. However, mining personnel, geophysicists included, are often unfamiliar with radar velocity and absorption. In this paper, general formulae are introduced, relating velocity and attenuation coefficient to conductivity and dielectric constant. The formulae are valid for lossy media as well as high-resistivity materials. The transformation of velocity and absorption to conductivity and dielectric constant is illustrated via application of the formulae to radar tomograms from the Hellyer zinc-lead-silver mine, Tasmania, Australia. The resulting conductivity and dielectric constant tomograms constructed at Hellyer demonstrated the potential of radar tomography to delineate sulphide ore zones. (C) 2001 Elsevier Science B.V. All rights reserved.

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The cotton bollworm (Helicoverpa armigera) prefers the common sowthistle (Sonchus oleraceus L.) to cotton (Gossypium hirsutum L.), sorghum (Sorghum bicolor L.) and maize (Zea mays L.) for oviposition in the field in Australia. Using the common sowthistle and cotton as host plants, we carried out this study to evaluate genetic variation in both oviposition preference and larval growth and genetic correlation between maternal preference and larval performance. There was a significant genetic component of phenotypic variation in both characters, and the heritability of oviposition preference was estimated as 0.602. Helicoverpa armigera larvae survived slightly better and grew significantly faster on common sowthistle than on cotton, but genetic correlation between maternal preference and larval growth performance was not detectable. Instead, larval growth performance on the two hosts changed with families, which renders the interaction between family and host plant significant. As a result, the genetic correlation between mean values of larval growth across the two host species was not different from zero. These results are discussed in the context of the relationship between H. armigera and the common sowthistle and the polyphagous behaviour of this insect in general.

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Dispersal, or the amount of dispersion between an individual's birthplace and that of its offspring, is of great importance in population biology, behavioural ecology and conservation, however, obtaining direct estimates from field data on natural populations can be problematic. The prickly forest skink, Gnypetoscincus queenslandiae, is a rainforest endemic skink from the wet tropics of Australia. Because of its log-dwelling habits and lack of definite nesting sites, a demographic estimate of dispersal distance is difficult to obtain. Neighbourhood size, defined as 4 piD sigma (2) (where D is the population density and sigma (2) the mean axial squared parent-offspring dispersal rate), dispersal and density were estimated directly and indirectly for this species using mark-recapture and microsatellite data, respectively, on lizards captured at a local geographical scale of 3 ha. Mark-recapture data gave a dispersal rate of 843 m(2)/generation (assuming a generation time of 6.5 years), a time-scaled density of 13 635 individuals * generation/km(2) and, hence, a neighbourhood size of 144 individuals. A genetic method based on the multilocus (10 loci) microsatellite genotypes of individuals and their geographical location indicated that there is a significant isolation by distance pattern, and gave a neighbourhood size of 69 individuals, with a 95% confidence interval between 48 and 184. This translates into a dispersal rate of 404 m(2)/generation when using the mark-recapture density estimation, or an estimate of time-scaled population density of 6520 individuals * generation/km(2) when using the mark-recapture dispersal rate estimate. The relationship between the two categories of neighbourhood size, dispersal and density estimates and reasons for any disparities are discussed.

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This paper aims to describe the historical outline and current development of the educational policy for students with learning difficulties in Australia, focusing especially on the state of Queensland. In order to develop educational policy of learning difficulities at the state level, the concept of learning difficulities had been discussed until the middle of the 1970's. Receiving the submissions which argued strongly against a diagnostically-oriented definition of learning disabilities, the Select Comittee concluded that there was much conceptual confusion regarding the definition and cause of learining difficulties that might take many years to resolve. Despite that it was recongnised that action was needed to assist children by looking at their "total learning environmerit", and recommended the development of an educational policy for students with learning difficulties. During 1980's, support teachers for students with learning difficulties were employed in many schools. Scince the early 1980's support teachers have been making their efforts in regular classrooms rather than in the resource rooms. Their roles have been to help students with learning difficulties using effective and specific skills, and to consult with the regular classroom teacher in solving the problems related to learning difficulties in regular classes. Currently, the support system for students with learning difficulties has been employed to organize a more systematic and broader approach in Queensland based on the accountability of schools. In the context of enphasizing literacy and numeracy, a systematic whole school approach and particular programs, such as the Year 2 Diagnostic Net and Reading Recovery, have been introduced into the educational system for early identification and early intervention.

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1. Species in the genus Neoseiulus are considered to be generalist predators. with some species used in biological control programmes against phytophagous mites and insects. 2. A general survey of Neoseiulus species in inland Australia indicated that different species are associated with particular tree species. This pattern of host plant use was investigated for four Neoseiulus species (N. buxeus, N. cappari, N. brigarinus, N. eremitus) by means of a sampling programme through time and across space. 3. Each species of Neoseiulus was collected entirely or mostly from one species of tree: little or no overlap was detected despite the tree species growing in well-mixed stands. Host plant specificity thus appears to be strong in this genus. 4. Species in two other genera (Pholaseius and Australiseiulus), also considered to be predatory, showed a similar association with particular tree species. 5. The implications for the use of these predators in biological control are considerable. In particular, phytoseiid species with specific needs in terms of host plants may not be suitable for use as general purpose predators. Meeting the needs of phytoseiids through the modification of host plant attributes may be a step towards enhancing their efficacy as biological control agents.

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The Biostatistics Collaboration of Australia (BCA) was formed in response to a shortage of statisticians seeking careers in the medical and health professions. The Collaboration has been successful in developing postgraduate courses (Graduate Certificate, Graduate Diploma and Masters) offered by a consortium of seven Australian Universities. These courses are available through a distance learning medium. The BCA was successful in securing funding from the Federal government to launch these courses, which commenced in March 2001. Two traineeships by the NSW Department of Health have also been awarded and a third is currently advertised. There has been close collaboration with governments, the pharmaceutical industry and research organisations to ensure that course content reflects practical problems and addresses industry needs. A second objective of the BCA is to provide ongoing workshops for practising biostatisticians to enhance professional development. These workshops serve to ring together biostatisticians from both within Australia and the Asia-Pacific region, providing a forum for discussion of current statistical thinking. (author abstract)

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The virulence spectrum of 112 isolates of Phytophthora clandestina collected from 56 sites in four subterranean clover-growing states in southern Australia was determined using differential cultivars of subterranean clover. Five races were detected, with race 0 in all states except New South Wales, race 1 in all states, race 2 only in Victoria, race 3 only in New South Wales, and race 4 in Victoria and Western Australia. The level of genotypic diversity among the different P. clandestina populations was investigated using five RAPD primers. Among 30 bands amplified, only two were polymorphic. This enabled identification of four multilocus RAPD genotypes. Three of the four genotypes occurred in all four states. Races 2 and 3 occurred with RAPD genotypes 1 and 2 only whereas races 0 and 1 occurred in all four multilocus RAPD genotypes. These results indicate that the pathogenicity spectrum of P. clandestina can change rapidly.

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We examined the genetic diversity of symbiotic dinoflagellates (Symbiodinium sp.) in the widespread hermatypic coral Plesiastrea versipora from tropical/subtropical (north-eastern Australia) and temperate waters (south-eastern Australia) using restriction fragment length polymorphisms of partial 18S ribosomal DNA (rDNA), together with sequence analysis of partial 28S rDNA. This study revealed that P. versipora associates with at least two distinct genotypes of symbiotic dinoflagellates and that the presence of these genotypes varies with latitude. P. versipora colonies from subtropical and tropical waters contained symbionts belonging to Symbiodinium clade C, while P. versipora colonies at high-latitude sites contained clade B. Variability within the two groups of symbionts (clades H and C) was minimal, suggesting possible host fidelity. The geographically distinct varieties of symbionts within the tissue of this hermatypic coral are likely to be associated with algal physiological differences, which in turn may relate to changing selective pressures as a function of latitude along the eastern Australian seaboard.

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Breeding methodologies for cultivated lucerne (Medicago sativa L.), an autotetraploid, have changed little over the last 50 years, with reliance on polycross methods and recurrent phenotypic selection. There has been, however, an increase in our understanding of lucerne biology, in particular the genetic relationships between members of the M. sativa complex, as deduced by DNA analysis. Also, the differences in breeding behaviour and vigour of diploids versus autotetraploids, and the underlying genetic causes, are discussed in relation to lucerne improvement. Medicago falcata, a member of the M. sativa complex, has contributed substantially to lucerne improvement in North America, and its diverse genetics would appear to have been under-utilised in Australian programs over the last two decades, despite the reduced need for tolerance to freezing injury in Australian environments. Breeding of lucerne in Australia only commenced on a large scale in 1977, driven by an urgent need to introgress aphid resistance into adapted backgrounds. The release in the early 1980s of lucernes with multiple pest and disease resistance (aphids, Phytophthora, Colletotrichum) had a significant effect on increasing lucerne productivity and persistence in eastern Australia, with yield increases under high disease pressure of up to 300% being recorded over the predominant Australian cultivar, up to 1977, Hunter River. Since that period, irrigated lucerne yields have plateaued, highlighting the need to identify breeding objectives, technologies, and the germplasm that will create new opportunities for increasing performance. This review discusses major goals for lucerne improvement programs in Australia, and provides indications of the germplasm sources and technologies that are likely to deliver the desired outcomes.

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This study describes the rehabilitation length of stay (LOS), discharge destination and discharge functional status of 149 patients admitted with traumatic brain injury (TBI) to an Australian hospital over a 5-year period. Hospital charts of patients admitted between 1993-1998 were reviewed. Average LOS over the 5-year time period was 61.8 days and only decreased nominally over this time. Longer LOS was predicted by lower admission motor FIM scores and presence of comorbidities. Mean admission and discharge motor FIM scores were 58 and 79, which represented a gain of 21 points. Higher discharge motor FIM scores were predicted by higher admission motor FIM scores and younger age. FIM gain was predicted by cognitive status and age. Most patients, 88%, were discharged back to the community, with 30% changing their living setting or situation. Changing living status was predicted by living alone and having poorer functional status on admission.