Social and Behavioral Sciences Commons^™

Living On The Edge-Plants And Global Change In Continental And Maritime Antarctica, Sharon A. Robinson, J. Wasley, A. K. Tobin

Faculty of Science - Papers (Archive)

Antarctic terrestrial ecosystems experience some of the most extreme growth conditions on Earth and are characterised by extreme aridity and sub-zero temperatures. Antarctic vegetation is therefore at the physiological limits of survival and, as a consequence, even slight changes to growth conditions are likely to have a large impact, rendering Antarctic terrestrial communities sensitive to climate change. Climate change is predicted to affect the high latitude regions first and most severely. In recent decades, the Antarctic has undergone significant environmental change, including the largest increases in ultraviolet B (UV-B; 290-320nm) radiation levels in the world and, in the maritime region …

Extreme Marine Inundations (Tsunamis?) Of Coastal Western Australia, J. Nott, Edward A. Bryant

Faculty of Science - Papers (Archive)

Along 2500 km of the Western Australian coast, prehistoric ephemeral marine inundations (storm surges or tsunamis) were much larger than those that occurred since European settlement. The evidence is in the form of shell and coral deposits atop 30-m-high headlands, sand deposits containing large boulders, shell and coral several kilometers inland, and fields of large imbricated boulders across shore platforms. The size of transported boulders and the altitude of these deposits suggest that tsunamis were responsible, not large storm waves. The orientation of boulders reveals paleowave directions. Radiocarbon dating of the deposits suggest three very large tsunamis along this coast …

Poly(2-Alkylacrylic Acid) Polymers Deliver Molecules To The Cytosol By Ph-Sensitive Disruption Of Endosomal Vesicles, Rachel A. Jones, C. Y. Cheung, F. E. Black, J. K. Zia, P. S. Stayton, A. S. Hoffman, Mark R. Wilson

Faculty of Science - Papers (Archive)

The permeability barrier posed by cell membranes represents a challenge for the delivery of hydrophilic molecules into cells. We previously proposed that poly(2- alkylacrylic acid)s are endocytosed by cells into acidified vesicles and are there triggered by low pH to disrupt membranes and release the contents of endosomes/lysosomes to the cytosol. If this hypothesis is correct, these polymers could be valuable in drug delivery applications. This report provides functional comparisons of a family of three poly(2-alkylacrylic acid)s. Poly(2-propylacrylic acid) (PPAA), poly(2-ethylacrylic acid) (PEAA), and poly(2-methylacrylic acid) (PMAA) were compared in red blood cell haemolysis assays and in a lipoplex gene …

Novel Pharmacophore Based Methods Reveal Gossypol As A Reverse Transcriptase Inhibitor, Paul A. Keller, C. Birch, S. P. Leach, D. Tyssen, R. Griffith

Faculty of Science - Papers (Archive)

In a program to identify new structural entities for the inhibition of the HIV-1 reverse transcriptase (RT) enzyme via database searching, a series of RT pharmacophores were developed. By utilising a novel filtering technique, the National Cancer Institute database of compounds was scanned producing 15 compounds to be screened for activity. A notable inclusion was a series of gossypol derivatives. The testing of a series of compounds revealed the parent compound gossypol to be an HIV-1 reverse transcriptase inhibitor. These results suggest that at least part of its anti-HIV activity is due to gossypol targeting the non-nucleoside inhibitor binding pocket …

Probing Dna Selectivity Of Ruthenium Metallointercalators Using Esi Mass Spectrometry, Jennifer L. Beck, Rajesh Gupta, Thitima Urathamakul, Nyree L. Williamson, Margaret Sheil, Janice Aldrich-Wright, Stephen F. Ralph

Faculty of Science - Papers (Archive)

ESI mass spectra show that up to five ruthenium molecules can bind non-covalently to double stranded 16mer DNA, and provide information on the relative affinity and DNA sequence selectivity of different ruthenium complexes.

Evolution Of Chemical Contaminant And Toxicology Studies, Part 2- Case Studies Of Selenium And Arsenic, Glennys O'Brien, Dianne Jolley, Robert John Morrison

Faculty of Science - Papers (Archive)

As the second of a two part series discussing the evolution of the field of environmental toxicology, this paper presents two case studies: selenium and arsenic. Developments over several decades in the understanding of the behaviour of arsenic and selenium in different chemical forms in various compartments of the environment are discussed. Selenium was initially thought to be toxic, but later investigations showed it to be an essential micronutrient with a variety of biochemical functions, and, importantly, that there is a very narrow gap between the essential and the toxic body burden. Arsenic, on the other hand, has not yet …

Application Of Rusle For Erosion Management In A Coastal Catchment, Southern Nsw, A. D. Simms, C. D. Woodroffe, B. G. Jones

Faculty of Science - Papers (Archive)

River catchments are dynamic and vulnerable systems that can change markedly when exposed to human impact. Changes induced since European settlement in Australia are of particular interest because impacts can be almost impossible to reverse. A measure of catchment degradation may be determined using accumulation in lakes. Along the east coast of New South Wales, both the rate of sediment infill and the stage of infill reached differ between coastal lagoons as a function of physical characteristics within their catchments, including the erosive power of rainfall, the intrinsic susceptibility of the soils to erosion, as well as the combined effect …

Asymmetric Synthesis Of (-)-7-Epiaustraline And (+)-1,7-Diepiaustraline, Minyan Tang, Stephen G. Pyne

Faculty of Science - Papers (Archive)

A diastereoselective and modular approach to the synthesis of the 3-hydroxymethyl-2,3,5,6,7,7a-hexahydro-1H-pyrrolizine-1,2,7-triol structure, characteristic of several natural pyrrolizidine natural products has been developed. This approach culminated in the synthesis of (-)-7-epiaustraline and (+)-1,7-diepiaustraline. The oxazolidinone group has been found to be a useful protecting group in the RCM reaction and, as part of a pyrrolo[1,2-c]oxazol-3-one ring system, has functioned as a stereo- and regio-directing group, in a key diastereoselective cis-dihydroxylation reaction and a regioselective nucleophilic ring-opening of a S,S-dioxo-dioxathiole.

Chemo-Enzymatic Synthesis Of (-)-Epipentenomycin I, Tawesin Klomklao, Stephen G. Pyne, Apiwat Baramee, Brian W. Skelton, Allan H. White

Faculty of Science - Papers (Archive)

A chemo-enzymatic synthesis of (−)-epipentenomycin I is reported using a lipase-catalysed kinetic resolution of the racemic pentacyclic alcohol 8. Flash vacuum pyroloysis of (−)-8 so obtained gave (−)-(4R)-4-hydroxy-5-methylene-2-cyclopentenone. Epoxidation of this compound with dimethyldioxirane followed by hydrolytic ring-opening of the resulting epoxide gave (−)-epipentenomycin I.

Photosynthesis In Silico: A Multimedia Cd-Rom Combining Animations, Simulations And Self-Paced Modules For Photosynthesis Education At All Tertiary Levels, Sharon A. Robinson, W. A. Russell, G. M.A. Netherwood

Faculty of Science - Papers (Archive)

Photosynthesis is a vital component of any undergraduate biology course. Despite its central importance in providing biochemical energy, fixed carbon and oxygen for all life on Earth, it remains an area which students find uninteresting and difficult to comprehend. This difficulty is compounded by problems with laboratory equipment for practical classes, which tends to be either expensive and complex, or simple and unreliable, making it extremely difficult to provide effective, hands-on teaching of photosynthesis to the large class sizes in undergraduate biology courses. A set of interactive, multimedia modules have been combined on a CD-ROM, which provides a new approach …

The Prevention Of Preterm Labour – Corticotropin Releasing Hormone Type 1 Receptors As A Target For Drug Design And Development, Paul A. Keller, K. Kirkwood, J. Morgan, S. Westcott, A. Mccluskey

Faculty of Science - Papers (Archive)

The role of the corticotropin releasing hormone in the onset of labour and the subsequent medicinal chemistry implications of CRH antagonists for the prevention of premature birth, and identification of the CRH type 1 receptor as the target for this drug design, are reviewed here.

Modelling Tropical Cyclone Disturbance Of The Great Barrier Reef Using Gis, Marji Puotinen

Faculty of Science - Papers (Archive)

Tropical cyclones periodically cross the Great Barrier Reef (GBR). Physical damage from the large waves they generate can significantly alter coral reef community structure over time. Yet cyclone disturbance of the GBR has not yet been examined for more than a few events and for only part of the region. Meteorological models can be used to hindcast the likely magnitude and distribution of cyclone energy from the Australian Bureau of Meteorology's tropical cyclone database. This hindcast energy, along with measures of the spatial patterning of reefs, can be linked statistically to field observations of reef impact to predict the distribution …

Changing Ecological Concerns In Rock-Art Subject Matter Of North Australia's Keep River Region, Paul Tacon, Ken Mulvaney, Sven Ouzman, Richard L. Fullagar, Lesley M. Head, Paddy Carlton

Faculty of Science - Papers (Archive)

The Keep River region has a complex body of engraved and painted rock-art, distinct from but with links to regions to the east, west and south. At least four major periods of figurative rock-art have been identified with differing subject matters and ages. Significant changes in depictions of human figures and animals are evident, reflecting shifts in emphasis associated with ecological concerns and environmental change. We flesh out the relative rock-art chronology by highlighting these changes, from worlds dominated by humans to those dominated by mammals and birds, and finally to a recent world of reptiles and humans. Symbolic aspects …

Development Of A Simple, Self-Consistent Polarizable Model For Liquid Water, Haibo Yu, Tomas Hansson, Wilfred Van Gunsteren

Faculty of Science - Papers (Archive)

The charge-on-spring method is used to develop a rigid, three-site, polarizable water model, a noniterative and a self-consistent version. In this method, the polarizability is taken into account by a variable separation of charges on selected polarizable centers. One of the pair of polarization charges resides on a polarizable center, while the other one is treated as an additional particle attached to the polarizable center by a parabolic restraint potential. The separation is calculated in response to the instantaneous electric field. We parametrized two models which are based on noniterative and self-consistent versions of the method, respectively. We computed several …

Tyrosine Phosphorylation Of Hsp-90 During Mammalian Sperm Capacitation, Heath W. Ecroyd, Russell C. Jones, Robert J. Aitken

Faculty of Science - Papers (Archive)

The process of sperm capacitation is correlated with activation of a signal transduction pathway leading to protein tyrosine phosphorylation. Whereas phosphotyrosine expression is an essential prerequisite for fertilization, the proteins that are phosphorylated during capacitation have not yet been identified. In the present study, we observed that a major target of this signaling pathway is the molecular chaperone protein, heat shock protein (HSP)-86, a member of the HSP-90 family of HSPs. We used cross-immunoprecipitation experiments to confirm the tyrosine phosphorylation of HSP-86, a process that is not inhibited by the ansamycin antibiotic, geldanamycin. The general significance of these findings was …

Endogenous Redox Activity In Mouse Spermatozoa And Its Role In Regulating The Tyrosine Phosphorylation Events Associated With Sperm Capacitation, Heath W. Ecroyd, Russell C. Jones, Robert J. Aitken

Faculty of Science - Papers (Archive)

We investigated the role of endogenous redox activity in regulating the signal transduction pathway leading to tyrosine phosphorylation in mouse spermatozoa. Endogenous redox activity was monitored using a luminol-peroxidase chemiluminescent probe. Chemiluminescence increased in spermatozoa that were actively undergoing cAMP-mediated tyrosine phosphorylation events associated with capacitation and was inhibited in a dose-dependent manner by addition of catalase or diphenylene iodonium, both of which also inhibited tyrosine phosphorylation within the cell at points downstream of cAMP. Excluding bicarbonate from the incubation medium reduced the redox activity of sperm by 80-90% and dramatically reduced tyrosine phosphorylation. This study provides the first evidence …

Small Heat-Shock Proteins And Clusterin: Intra- And Extracellular Molecular Chaperones With A Common Mechanism Of Action And Function, J. A. Carver, A. Rekas, D. C. Thorn, M. R. Wilson

Faculty of Science - Papers (Archive)

Small heat-shock proteins (sHsps) and clusterin are molecular chaperones that share many functional similarities despite their lack of significant sequence similarity. These functional similarities, and some differences, are discussed. sHsps are ubiquitous intracellular proteins whereas clusterin is generally found extracellularly. Both chaperones potently prevent the amorphous aggregation and precipitation of target proteins under stress conditions such as elevated temperature, reduction and oxidation. In doing so, they act on the slow off-folding protein pathway. The conformational dynamism and aggregated state of both proteins may be crucial for their chaperone function. Subunit exchange is likely to be important in regulating chaperone action; …

Applications Of Airborne Laser Scanning To Manage Coastal Acid Sulfate Soils Within The Broughton Creek Floodplain, Marcus Morgan, Warwick Papworth, Peter Aney, John Perry, Buddhima Indraratna

Faculty of Science - Papers (Archive)

Airborne Laser Scanning (ALS) Was first used in 1993 by Geodan Geodesie B. V. as a cheaper alternative in the collection of spatial information than traditional survey methods and photogrammetry. ALS has become important in creating Digital Terrain Models (DTM) with high precision at a far lower cost to other methods. Shoalhaven City Council employed ALS in May 200 I for the purpose of obtaining detailed survey information within budgetary constraints. The aim Was to determine the effectiveness of using ALS for coastal and environmental management by testing the accuracy of ground level points against traditionally surveyed points.

Coastal Acid …

Environmental (Re)Education And Local Environmental Knowledge: Statutory Ground-Based Monitoring And Pastoral Culture In Central Australia, Nicholas J. Gill

Faculty of Science - Papers (Archive)

Ground-based monitoring of rangeland condition is common in Australian pastoral administration systems. In the Northern Territory, such monitoring is officially seen as a key plank of sustainable pastoral land use. In the NT and elsewhere, these monitoring schemes have sought to increase participation by pastoralists. Involvement of pastoralists in monitoring is theoretically an educative process that will cause pastoralists to more critically examine their management practices. Critical perspectives on the relationship between rangelands science/extension and pastoralist knowledge systems and concerns, however, suggest that pastoralists’ reception of such monitoring schemes will be influenced by a range of social contexts, including the …

Diagenesis And Geochemistry Of Porites Corals From Papua New Guinea: Implications For Paleoclimate Reconstruction, Helen V. Mcgregor, M Gagan

Faculty of Science - Papers (Archive)

No abstract provided.

Evolution Of Chemical Contaminant And Toxicology Studies, Part 1 - An Overview, Dianne F. Jolley, Glennys A. O'Brien, Robert John Morrison

Faculty of Science - Papers (Archive)

The study of environmental chemical contaminants and their toxicological effects has changed dramatically over the last 50 years. Initially studies concentrated on trying to identify what contaminants were actually present and to develop quantitative methods to determine the concentrations (total) present. Health impacts were often investigated independently in medical research centres. With improving analytical techniques, studies of the speciation of contaminants began and the specific forms that were creating the major problems were gradually identified. Continuing improvements in analytical chemistry, together with a move towards more integrated and multidisciplinary research now sees chemists, biologists, toxicologists and health researchers working closely …

Stemocurtisine, The First Pyrido[1,2-A]Azapine Stemona Alkaloid, Pitchaya Mungkornasawakul, Stephen G. Pyne, Araya Jatisatienr, Damrat Supyen, Wilford Lie, Alison T. Ung, Brian W. Skelton, Allan H. White

Faculty of Science - Papers (Archive)

A new pentacyclic stemona alkaloid, stemocurtisine (2), with a novel pyrido[1,2-a]azapine A,B-ring system, has been isolated from a root extract of Stemona curtisii. The structure and relative stereochemistry was determined by spectral data interpretation and X-ray crystallography.