1,115 research outputs found

    The effects of fire on burrow-nesting seabirds particularly short-tailed shearwaters (Puffinus tenuirostris) and their habitat in Tasmania

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    The synchronised breeding habit of many seabird species makes them particularly vulnerable to fires in the nesting area. Post-fire recolonisation and soil formation were studied on Albatross Island, and observations from island rookeries of shearwaters, fairy prions and fairy penguins in eastern Bass Strait and elsewhere were used with a view to understanding the long-term impact of fires on seabird colonies in Tasmania

    Notes on rare, vagrant and exotic avifauna at Macquarie Island, 1901-2000

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    The occurrence and status of rare, vagrant and exotic bird taxa recorded at Macquarie Island between 1901 and 2000 are reviewed. The number of species recorded at the island, excluding those that have bred regularly on the main island between 1901 and 2000, is increased to 56 non-breeding species, seven species that have been confirmed breeding since 1980 and four introduced/exotic species breeding on the island

    The avifauna of Bishop and Clerk islets and its relationship to nearby Macquarie Island

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    A first comprehensive survey of seabirds at Bishop and Clerk islets conducted on 23 December 1993 recorded a total of 12 species. During a three-hour-long visit by helicopter, nine species were found breeding, mostly in nests on the ground, but also in burrows dug in shallow soil. These included the largest known colony of Black-browed Albatross, Thalassarche melanophris, in Australia. Ten bird species are now known to breed at the islets. Specics accounts are given including data on morphometries, abundance, habitats, breeding, threats, interspecific competition for space and unpublished information

    The response of burrow-nesting petrels and other vulnerable bird species to vertebrate pest management and climate change on sub-Antarctic Macquarie Island

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    Pest species management is causing rapid and significant changes to burrow-nesting petrel populations on sub-Antarctic Macquarie Island. The Weka, Gallirallus australis, was eliminated by 1989 and the Feral Cat, Felis catus, eradicated in 2000. The most abundant burrownesting petrel species currently, White-headed Petrels, Pterodroma lessonii, Antarctic Prions, Pachyptila desolata, and Sooty Shearwaters, Puffinus griseus, have yet to increase in numbers, but are expected to do so in the absence of cats. This study found evidence that Grey Petrels, Procell aria cinerea, began breeding again on the island in 1999, after an absence of over 100 years. Blue Petrels, Halobaena caerulea, and Fairy Prions, Pachyptila turtur, were found to be re-colonising Macquarie Island from offshore stacks after a similar absence. South Georgian Diving-Petrels, Pelecanoides georgicus, were also possibly recolonising the island. Despite the presence of Black Rats, Rattus rattus, most of the bird species discussed are considered capable of population increase. If European Rabbits, Oryctolagus cuniculus, are not eliminated or maintained in reduced numbers, some petrel populations will never fully recover. Climate change could have a negative impact on burrow-nesting petrels, and is likely to exacerbate the detrimental effects of the remaining pest species on vulnerable indigenous bird species, compounding the need for remedial action against rabbits in particular. Together with predictions that other petrel species will now return to breed, certain terrestrial bird species, alien to the region, may invade Macquarie Island as a consequence of the combination of pest eradication and changing climatic conditions

    The role of screened exact exchange in accurately describing properties of transition metal oxides: Modeling defects in LaAlO3

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    The properties of many intrinsic defects in the wide band gap semiconductor LaAlO3 are studied using the screened hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE). As in pristine structures, exact exchange included in the screened hybrid functional alleviates the band gap underestimation problem, which is common to semilocal functionals; this allows accurate prediction of defect properties. We propose correction-free defect energy levels for bulk LaAlO3 computed using HSE that might serve as guide in the interpretation of photoluminescence experiments

    Predators on marine fish farms in Tasmania

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    Marine aquaculture of the salmonids atlantic salmon (Salrno salar) and rainbow trout (Salmo gairdneri) is a rapidly growing industry in Tasmania. There is considerable damage to the fish on these farms by avian and mammalian predators. The mode by which these predators attack the fish on the farms allows for practical methods to reduce the loss of fish. Physically excluding predators from the fish is ultimately the only way to prevent this loss entirely. A total of six predators that interact with the farms are described and the necessity for the protection methods to be incorporated into the design of the farms prior to farm development is emphasised

    Structural Phase Transitions of the Metal Oxide Perovskites SrTiO3, LaAlO3 and LaTiO3 Studied with a Screened Hybrid Functional

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    We have investigated the structural phase transitions of the transition metal oxide perovskites SrTiO3_{3}, LaAlO3_{3} and LaTiO3_{3} using the screened hybrid density functional of Heyd, Scuseria and Ernzerhof (HSE06). We show that HSE06-computed lattice parameters, octahedral tilts and rotations, as well as electronic properties, are significantly improved over semilocal functionals. We predict the crystal field splitting (Ξ”CF\Delta_{CF}) resulting from the structural phase transition in SrTiO3_{3} and LaAlO3_{3} to be 3 meV and 10 meV, respectively, in excellent agreement with experimental results. HSE06 identifies correctly LaTiO3_{3} in the magnetic sates as a Mott insulator. Also, it predicts that the GdFeO3_{3}-type distortion in non-magnetic LaTiO3_{3} will induce a large Ξ”CF\Delta_{CF} of 410 meV. This large crystal-field splitting associated with the large magnetic moment found in the G-type antiferromagnetic state suggest that LaTiO3_{3} has an induced orbital order, which is confirmed by the visualisation of the highest occupied orbitals. These results strongly indicate that HSE06 is capable of efficiently and accurately modeling perovskite oxides, and promises to efficiently capture the physics at their heterointerfaces

    Genetic Variation and Antioxidant Response Gene Expression in the Bronchial Airway Epithelium of Smokers at Risk for Lung Cancer

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    Prior microarray studies of smokers at high risk for lung cancer have demonstrated that heterogeneity in bronchial airway epithelial cell gene expression response to smoking can serve as an early diagnostic biomarker for lung cancer. As a first step in applying functional genomic analysis to population studies, we have examined the relationship between gene expression variation and genetic variation in a central molecular pathway (NRF2-mediated antioxidant response) associated with smoking exposure and lung cancer. We assessed global gene expression in histologically normal airway epithelial cells obtained at bronchoscopy from smokers who developed lung cancer (SC, n=20), smokers without lung cancer (SNC, n=24), and never smokers (NS, n=8). Functional enrichment analysis showed that the NRF2-mediated, antioxidant response element (ARE)-regulated genes, were significantly lower in SC, when compared with expression levels in SNC. Importantly, we found that the expression of MAFG (a binding partner of NRF2) was correlated with the expression of ARE genes, suggesting MAFG levels may limit target gene induction. Bioinformatically we identified single nucleotide polymorphisms (SNPs) in putative ARE genes and to test the impact of genetic variation, we genotyped these putative regulatory SNPs and other tag SNPs in selected NRF2 pathway genes. Sequencing MAFG locus, we identified 30 novel SNPs and two were associated with either gene expression or lung cancer status among smokers. This work demonstrates an analysis approach that integrates bioinformatics pathway and transcription factor binding site analysis with genotype, gene expression and disease status to identify SNPs that may be associated with individual differences in gene expression and/or cancer status in smokers. These polymorphisms might ultimately contribute to lung cancer risk via their effect on the airway gene expression response to tobacco-smoke exposure.Intramural Research Program of the National Institute of Environmental Health Sciences; National Institutes of Health (Z01 ES100475, U01ES016035, R01CA124640
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