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Full-Text Articles in Social and Behavioral Sciences

Automatic Reaction To A Chemical Event Detected By A Low-Cost Wireless Chemical Sensing Network, Stephen Beirne, King Tong Lau, Brian Corcoran, Dermot Diamond Dec 2008

Automatic Reaction To A Chemical Event Detected By A Low-Cost Wireless Chemical Sensing Network, Stephen Beirne, King Tong Lau, Brian Corcoran, Dermot Diamond

Faculty of Science - Papers (Archive)

A test-scale wireless chemical sensor network (WCSN) has been deployed within a controlled Environmental Chamber (EC). The combined signals from the WCSN were used to initiate a controllable response to the detected chemical event. When a particular sensor response pattern was obtained, a purging cycle was initiated. Sensor data were continuously checked against user-defined action limits, to determine if a chemical event had occurred. An acidic contaminant was used to demonstrate the response of the sensor network. Once the acid plume was simultaneously detected by a number of wireless chemical sensor nodes, an automatic response action, which was the purging ...


Dynamics Of Apomyoglobin In The Α-To-Β Transition And Of Partially Unfolded Aggregated Protein, E. Fabiani, A. M. Stadler, D. Madern, M. M. Koza, M. Tehei, M. Hirai, G. Zaccai Oct 2008

Dynamics Of Apomyoglobin In The Α-To-Β Transition And Of Partially Unfolded Aggregated Protein, E. Fabiani, A. M. Stadler, D. Madern, M. M. Koza, M. Tehei, M. Hirai, G. Zaccai

Faculty of Science - Papers (Archive)

Changes of molecular dynamics in the α-to-β transition associated with amyloid fibril formation were explored on apo-myoglobin (ApoMb) as a model system. Circular dichroism, neutron and X-ray scattering experiments were performed as a function of temperature on the protein, at different solvent conditions. A significant change in molecular dynamics was observed at the α-to-β transition at about 55 ˚C, indicating a more resilient high temperature β structure phase. A similar effect at approximately the same temperature was observed in holo-myoglobin, associated with partial unfolding and protein aggregation. A study in a wide temperature range between 20 K and 360 K ...


M Protein Mediated Plasminogen Binding Is Essential For The Virulence Of An Invasive Streptococcus Pyogenes Isolate, Martina L. Sanderson-Smith, K. Dinkla, J. N. Cole, Amanda J. Cork, P. G. Maamary, Jason D. Mcarthur, G. S. Chhatwal, Mark J. Walker Sep 2008

M Protein Mediated Plasminogen Binding Is Essential For The Virulence Of An Invasive Streptococcus Pyogenes Isolate, Martina L. Sanderson-Smith, K. Dinkla, J. N. Cole, Amanda J. Cork, P. G. Maamary, Jason D. Mcarthur, G. S. Chhatwal, Mark J. Walker

Faculty of Science - Papers (Archive)

The human protease plasmin plays a crucial role in the capacity of the group A streptococcus (Streptococus pyogenes; GAS) to initiate invasive disease. The GAS strain NS88.2 was isolated from a case of bacteremia from the Northern Territory of Australia, a region with high rates of GAS invasive disease. Mutagenesis of the NS88.2 plasminogen binding M protein Prp was undertaken to examine the contribution of plasminogen binding and cell surface plasmin acquisition to virulence. The isogenic mutant NS88.2prp was engineered whereby four amino acid residues critical for plasminogen binding were converted to alanine codons in the GAS ...


Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina Aug 2008

Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina

Faculty of Science - Papers (Archive)

The alpha-crystallins are members of the small heat shock protein (sHSP) family of molecular chaperones which have evolved to minimize intracellular protein aggregation, however they are also implicated in a number of protein deposition diseases. In this study we have employed novel mass spectrometry techniques to investigate the changes in quaternary structure associated with this switch from chaperone to adjuvant of aggregation. We have replicated the oligomeric rearrangements observed for in vivo disease-related modifications, without altering the protein sequence, by refolding the alpha-crystallins in vitro. This refolding results in a loss of dimeric substructure concomitant with an augmentation of substrate ...


Cell Wall-Bound Ultraviolet-Screening Compounds Explain The High Ultraviolet Tolerance Of The Antarctic Moss, Ceratodon Purpureus, L. J. Clarke, Sharon A. Robinson Aug 2008

Cell Wall-Bound Ultraviolet-Screening Compounds Explain The High Ultraviolet Tolerance Of The Antarctic Moss, Ceratodon Purpureus, L. J. Clarke, Sharon A. Robinson

Faculty of Science - Papers (Archive)

Studies of ultraviolet (UV) light-induced DNA damage in three Antarctic moss species have shown Ceratodon purpureus to be the most UV tolerant, despite containing lower concentrations of methanol-soluble UV-screening compounds than the co-occurring Bryum pseudotriquetrum. In this study, alkali extraction of cell wall-bound phenolics, combined with methanol extraction of soluble phenolics, was used to determine whether cell wall-bound UV screens explain the greater UV tolerance of C. purpureus. The combined pool of UV screens was similar in B. pseudotriquetrum and C. purpureus, but whilst B. pseudotriquetrum had almost equal concentrations of MeOH-soluble and alkali-extractable cell wall-bound UV-screening compounds, in C ...


Mid-Holocene Enso: Issues In Quantitative Model-Proxy Data Comparisons, J Brown, A W. Tudhope, M Collins, H V. Mcgregor Jul 2008

Mid-Holocene Enso: Issues In Quantitative Model-Proxy Data Comparisons, J Brown, A W. Tudhope, M Collins, H V. Mcgregor

Faculty of Science - Papers (Archive)

Evaluation of climate model simulations using observed data contributes to the assessment of confidence in model predictions of future climate change. The mid-Holocene represents an opportunity to evaluate model simulations of El Niño–Southern Oscillation (ENSO) in comparison with coral proxy evidence of reduced ENSO amplitude. Quantitative comparisons between coral records and model output have been limited by (1) the use of different measures of ENSO amplitude, (2) possible sampling of natural variability in short records, and (3) uncertainty about the stationarity of the relationship between central Pacific sea surface temperature (SST) variability and ENSO signals at the coral site ...


Allelic Variants Of Streptokinase From Streptococcus Pyogenes Display Functional Differences In Plasminogen Activation., Jason D. Mcarthur, F. C. Mckay, V. Ramachandran, P. Shyam, Amanda J. Cork, Martina L. Sanderson-Smith, J. N. Cole, U. Ringdahl, U. Sjobring, M. Ranson, Mark J. Walker May 2008

Allelic Variants Of Streptokinase From Streptococcus Pyogenes Display Functional Differences In Plasminogen Activation., Jason D. Mcarthur, F. C. Mckay, V. Ramachandran, P. Shyam, Amanda J. Cork, Martina L. Sanderson-Smith, J. N. Cole, U. Ringdahl, U. Sjobring, M. Ranson, Mark J. Walker

Faculty of Science - Papers (Archive)

A common mammalian defence mechanism employed to prevent systemic dissemination of invasive bacteria involves occlusion of local microvasculature and encapsulation of bacteria within fibrin networks. Acquisition of plasmin activity at the bacterial cell surface circumvents this defence mechanism allowing invasive disease initiation. To facilitate this process, S. pyogenes secrete streptokinase, a plasminogen activating protein. Streptokinase polymorphism exhibited by S. pyogenes isolates is well characterised. However, the functional differences displayed by these variants and the biological significance of this variation has not been elucidated. Phylogenetic analysis of ska sequences from 28 S. pyogenes isolates revealed two main sequence clusters (clusters 1 ...


Down To Atomic-Scale Intracellular Water Dynamics, M. Jasnin, M. Moulin, M. Haertlein, G. Zaccai, M. Tehei May 2008

Down To Atomic-Scale Intracellular Water Dynamics, M. Jasnin, M. Moulin, M. Haertlein, G. Zaccai, M. Tehei

Faculty of Science - Papers (Archive)

Water constitutes the intracellular matrix in which biological molecules interact. Understanding its dynamic state is a main scientific challenge, which continues to provoke controversy after more than 50 years of study. We measured water dynamics in vivo in the cytoplasm of Escherichia coli by using neutron scattering and isotope labelling. Experimental timescales covered motions from pure water to interfacial water, on an atomic length scale. In contrast to the widespread opinion that water is ‘tamed’ by macromolecular confinement, the measurements established that water diffusion within the bacteria is similar to that of pure water at physiological temperature.


In Vivo Measurement Of Internal And Global Macromolecular Motions In E. Coli, M. Jasnin, M. Moulin, M. Haertlein, G. Zaccai, M. Tehei Mar 2008

In Vivo Measurement Of Internal And Global Macromolecular Motions In E. Coli, M. Jasnin, M. Moulin, M. Haertlein, G. Zaccai, M. Tehei

Faculty of Science - Papers (Archive)

We present direct quasielastic neutron scattering measurements, in vivo, of macromolecular dynamics in E. coli. The experiments were performed on a wide range of time-scales, to cover the large panel of internal and self-diffusion motions. Three major internal processes were extracted at physiological temperature: a fast picosecond (ps) process that corresponded to restricted jump diffusion motions, and two slower processes that resulted from reorientational motions occurring in about 40 ps and 90 ps, respectively. The analysis of the fast process revealed that the cellular environment leads to an appreciable increase in internal molecular flexibility and diffusive motion rates compared to ...


Opacity Factor Activity And Epithelial Cell Binding By The Serum Opacity Factor Protein Of Streptococcus Pyogenes Are Functionally Discrete, C. M. Gillen, H. S. Courtney, K. Schulze, M. Rohde, Mark R. Wilson, A. M. Timmer, C. A. Guzman, V. Nizet, G. S. Chhatwal, Mark J. Walker Mar 2008

Opacity Factor Activity And Epithelial Cell Binding By The Serum Opacity Factor Protein Of Streptococcus Pyogenes Are Functionally Discrete, C. M. Gillen, H. S. Courtney, K. Schulze, M. Rohde, Mark R. Wilson, A. M. Timmer, C. A. Guzman, V. Nizet, G. S. Chhatwal, Mark J. Walker

Faculty of Science - Papers (Archive)

Serum opacity factor (SOF) is a unique multifunctional virulence determinant expressed at the surface of Streptococcus pyogenes and has been shown to elicit protective immunity against GAS infection in a murine challenge model. SOF consists of two distinct domains with different binding capacities: an N-terminal domain that binds apolipoprotein AI and a C-terminal repeat domain that binds fibronectin and fibrinogen. The capacity of SOF to opacify serum by disrupting the structure of high density lipoproteins may preclude its use as a vaccine antigen in humans. This study generated mutant forms of recombinant SOF with reduced (100-fold) or abrogated opacity factor ...


Somatic Mutation And The Antarctic Ozone Hole, L. J. Clarke, Sharon A. Robinson, D. J. Ayre Mar 2008

Somatic Mutation And The Antarctic Ozone Hole, L. J. Clarke, Sharon A. Robinson, D. J. Ayre

Faculty of Science - Papers (Archive)

1 Previous studies of Antarctic clonal moss populations using RAPD markers have reported extraordinarily high levels of genetic variation. This has been claimed to reflect somatic mutation, possibly resulting from elevated UV-B radiation. 2 Our study used microsatellite markers to compare the genetic variation present within continental Antarctic, sub-Antarctic and temperate populations of the moss Ceratodon purpureus. 3 In contrast to the RAPD studies, microsatellite data revealed that C. purpureus populations from continental Antarctica display less intra-population genetic diversity than populations from a range of temperate and sub-Antarctic sites. 4 Analysis of Molecular Variation (AMOVA) revealed that populations within the ...


Solvent Isotope Effect On Macromolecular Dynamics In E. Coli, M. Jasnin, M. Tehei, M. Moulin, M. Haertlein, G. Zaccai Feb 2008

Solvent Isotope Effect On Macromolecular Dynamics In E. Coli, M. Jasnin, M. Tehei, M. Moulin, M. Haertlein, G. Zaccai

Faculty of Science - Papers (Archive)

Elastic incoherent neutron scattering was used to explore solvent isotope effects on average macromolecular dynamics in vivo. Measurements were performed on living E. coli bacteria containing H2O and D2O, respectively, close to physiological conditions of temperature. Global macromolecular flexibility, expressed as mean square fluctuation (MSF) values, and structural resilience in a free energy potential, expressed as a mean effective force constant, hk0i, were extracted in the two solvent conditions. They referred to the average contribution of all macromolecules inside the cell, mostly dominated by the internal motions of the protein fraction. Flexibility and resilience were both found to be smaller ...


Synchronicity Of Thermogenic Activity, Alternative Pathway Respiratory Flux, Aox Protein Content, And Carbohydrates In Receptacle Tissues Of Sacred Lotus During Floral Development, Nicole M. Grant, Rebecca E. Miller, Jennifer R. Watling, Sharon A. Robinson Feb 2008

Synchronicity Of Thermogenic Activity, Alternative Pathway Respiratory Flux, Aox Protein Content, And Carbohydrates In Receptacle Tissues Of Sacred Lotus During Floral Development, Nicole M. Grant, Rebecca E. Miller, Jennifer R. Watling, Sharon A. Robinson

Faculty of Science - Papers (Archive)

The relationships between heat production, alternative oxidase (AOX) pathway flux, AOX protein, and carbohydrates during floral development in Nelumbo nucifera (Gaertn.) were investigated. Three distinct physiological phases were identified: pre-thermogenic, thermogenic, and post-thermogenic. The shift to thermogenic activity was associated with a rapid, 10-fold increase in AOX protein. Similarly, a rapid decrease in AOX protein occurred post-thermogenesis. This synchronicity between AOX protein and thermogenic activity contrasts with other thermogenic plants where AOX protein increases some days prior to heating. AOX protein in thermogenic receptacles was significantly higher than in post-thermogenic and leaf tissues. Stable oxygen isotope measurements confirmed that the ...


Trend Analysis Of Greenhouse Gases Over Europe Measured By A Network Of Ground-Based Remote Ftir Instruments, T Gardiner, A Forbes, M De Maziere, C Vigouroux, E Mahieu, P Demoulin, Voltaire A. Velazco, J Notholt, T Blumenstock, F Hase, I Kramer, R Sussmann, W Stremme, J Mellqvist, A Strandberg, K Ellingsen, M Gauss Jan 2008

Trend Analysis Of Greenhouse Gases Over Europe Measured By A Network Of Ground-Based Remote Ftir Instruments, T Gardiner, A Forbes, M De Maziere, C Vigouroux, E Mahieu, P Demoulin, Voltaire A. Velazco, J Notholt, T Blumenstock, F Hase, I Kramer, R Sussmann, W Stremme, J Mellqvist, A Strandberg, K Ellingsen, M Gauss

Faculty of Science - Papers (Archive)

This paper describes the statistical analysis of annual trends in long term datasets of greenhouse gas measurements taken over ten or more years. The analysis technique employs a bootstrap resampling method to determine both the long-term and intra-annual variability of the datasets, together with the uncertainties on the trend values.


Vegetation Over Hydrologic Control Of Sediment Transport Over The Past 100,000 Yr, Anthony Dosseto, Simon Turner, P P Hesse, Kate Maher, Kirstie Fryirs Jan 2008

Vegetation Over Hydrologic Control Of Sediment Transport Over The Past 100,000 Yr, Anthony Dosseto, Simon Turner, P P Hesse, Kate Maher, Kirstie Fryirs

Faculty of Science - Papers (Archive)

No abstract provided.


Chemical Event Tracking Using A Low-Cost Wireless Chemical Sensing Network, Stephen T. Beirne, B Corcoran, K T Lau, D Diamond Jan 2008

Chemical Event Tracking Using A Low-Cost Wireless Chemical Sensing Network, Stephen T. Beirne, B Corcoran, K T Lau, D Diamond

Faculty of Science - Papers (Archive)

A recently developed low-cost light emitting diode (LED) chemical sensing technique is integrated with a Mica2Dot wireless communications platform to form a deployable wireless chemical event indicator network. The operation of the colorimetric sensing node has been evaluated to determine its reproducibility and limit of detection for an acidic airborne contaminant. A test-scale network of five similar chemical sensing nodes is deployed in a star communication topology at fixed points within a custom built Environmental Sensing Chamber (ESC). Presented data sets collected from the deployed wireless chemical sensor network (WCSN) show that during an acidic event scenario it is possible ...


Electrochemical Co-Deposition Of Tin+ Phases With Gold In Ionic Liquids, Jie Ding, Jian Wu, Douglas R. Macfarlane, William E. Price, Gordon G. Wallace Jan 2008

Electrochemical Co-Deposition Of Tin+ Phases With Gold In Ionic Liquids, Jie Ding, Jian Wu, Douglas R. Macfarlane, William E. Price, Gordon G. Wallace

Faculty of Science - Papers (Archive)

The electro-deposition of titanium from two different classes of ionic liquids has been studied. Gold ions in solution have been used as an additive in order to provide a stable nucleation site for titanium to deposit on via a co-deposition process. Despite evidence from previous literature, it was found that it was not possible to reduce titanium from the +4 state to titanium (0) due to problems of redox cycling and solubility of reduced titanium species in the various ILs trialled. It was however found that gold was a very effective nucleating agent for these reduced titanium species and that ...


Diastereoselective Ritter Reactions Of Chiral Cyclic N-Acyliminium Ions: Synthesis Of Pyrido- And Pyrrolo [2,3-D] Oxazoles And 4-Hydroxy-5-N-Acylaminopyrrolidines And 5-Hydroxy-6-N-Acylaminopiperidines, Ian R. Morgan, Arife Yazici, Stephen G. Pyne, Brian W. Skelton Jan 2008

Diastereoselective Ritter Reactions Of Chiral Cyclic N-Acyliminium Ions: Synthesis Of Pyrido- And Pyrrolo [2,3-D] Oxazoles And 4-Hydroxy-5-N-Acylaminopyrrolidines And 5-Hydroxy-6-N-Acylaminopiperidines, Ian R. Morgan, Arife Yazici, Stephen G. Pyne, Brian W. Skelton

Faculty of Science - Papers (Archive)

Pyrido- and pyrrolo[2,3-d]oxazoles can be conveniently prepared in high yield from the Ritter reaction of nitriles and in situ generated chiral cyclic N-acyliminium ions. cis-4-Hydroxy-5-acylaminopyrrolidines and cis-5-hydroxy-6-acylaminopiperidines can be readily obtained by acid hydrolysis of these bicyclic heterocyclic compounds, respectively.


Integrated Late Quaternary Chronostratigraphy For San Salvador Island, Bahamas: Patterns And Trends Of Morphological Change In The Land Snail Cerion, Paul Hearty, Stephen A. Schellenberg Jan 2008

Integrated Late Quaternary Chronostratigraphy For San Salvador Island, Bahamas: Patterns And Trends Of Morphological Change In The Land Snail Cerion, Paul Hearty, Stephen A. Schellenberg

Faculty of Science - Papers (Archive)

Reconstructing the phylogeny and biogeography of the Caribbean land snail Cerion requires a robust stratigraphic and chronological framework. To this end, we have determined the stratigraphic succession on San Salvador, a Bahamian island with a rich fossil and modern Cerion fauna. A primary purpose of this paper is to independently verify this succession through whole-rock and Cerion aminostratigraphies and AMS 14C-based age models. Over 150 individual Cerion shells were age-ranked from 140 ka to modern using stratigraphic position and reverse-phase HPLC (RPC) amino acid racemization, which was sufficiently sensitive to resolve stratigraphic subunits within the Holocene and late Pleistocene ...


Distribution And Sources Of Organic Carbon, Nitrogen And Their Isotopic Signatures In Sediments From The Ayeyarwady (Irrawaddy) Continental Shelf, Northern Andaman Sea, V Ramaswamy, Birgit Gaye, P V. Shirodkar, P S. Rao, Allan Chivas, David J. Wheeler, Swe Thwin Jan 2008

Distribution And Sources Of Organic Carbon, Nitrogen And Their Isotopic Signatures In Sediments From The Ayeyarwady (Irrawaddy) Continental Shelf, Northern Andaman Sea, V Ramaswamy, Birgit Gaye, P V. Shirodkar, P S. Rao, Allan Chivas, David J. Wheeler, Swe Thwin

Faculty of Science - Papers (Archive)

Total organic carbon (TOC), total nitrogen (TN) and their δ13C and δ15N values were determined from 110 sediment samples from the Ayeyarwady (Irrawaddy) continental shelf, northern Andaman Sea to decipher the concentration and source of organic matter. Comparatively higher TOC and TN concentrations are found in the inner-shelf mud belt, and on the continental slope sediments, whereas the outer-shelf sediments, composed mostly of relict sands, are low in TOC. The TOC contents are positively correlated with the abundance of fine-grained sediments. The TOC:TN ratios and δ13C and δ15N values show low ...


Exploiting The Borono-Mannich Reaction In Bioactive Alkaloid Synthesis, Stephen G. Pyne, Christopher Au, Andrew S. Davis, Ian R. Morgan, Thunwadee Ritthiwigrom, Arife Yazici Jan 2008

Exploiting The Borono-Mannich Reaction In Bioactive Alkaloid Synthesis, Stephen G. Pyne, Christopher Au, Andrew S. Davis, Ian R. Morgan, Thunwadee Ritthiwigrom, Arife Yazici

Faculty of Science - Papers (Archive)

We have demonstrated that the borono-Mannich reaction is a versatile and efficient reaction for the diastereoselective preparation of chiral 1,2-amino alcohols. These Mannich products are valuable starting materials as shown in this report by the synthesis of bioactive polyhydroxylated pyrrolizidine and indolizidine alkaloids. Initial studies, directed at the more complex Stemona alkaloids, using the borono-Mannich reaction on cyclic N-acyliminium ions are encouraging as demonstrated by the synthesis of the pyrido[1,2-a]azepine core structure of stemocurtisinol.


Land Management And Land Cover On Land Owned By Amenity Oriented Rural Landowners In Jamberoo Valley, Nicholas J. Gill, Laurie A. Chisholm, Peter Klepeis, Rohan Wickramasuriya, John K. Marthick Jan 2008

Land Management And Land Cover On Land Owned By Amenity Oriented Rural Landowners In Jamberoo Valley, Nicholas J. Gill, Laurie A. Chisholm, Peter Klepeis, Rohan Wickramasuriya, John K. Marthick

Faculty of Science - Papers (Archive)

No abstract provided.


Evaluation Of Tropospheric And Stratospheric Ozone Trends Over Western Europe From Ground-Based Ftir Network Observations, C Vigouroux, M De Maziere, P Demoulin, C Servais, F Hase, T Blumenstock, I Kramer, M Schneider, J Mellqvist, A Strandberg, Voltaire A. Velazco, J Notholt, R Sussmann, W Stremme, A Rockmann, T Gardiner, M Coleman, P Woods Jan 2008

Evaluation Of Tropospheric And Stratospheric Ozone Trends Over Western Europe From Ground-Based Ftir Network Observations, C Vigouroux, M De Maziere, P Demoulin, C Servais, F Hase, T Blumenstock, I Kramer, M Schneider, J Mellqvist, A Strandberg, Voltaire A. Velazco, J Notholt, R Sussmann, W Stremme, A Rockmann, T Gardiner, M Coleman, P Woods

Faculty of Science - Papers (Archive)

Within the European project UFTIR (Time series of Upper Free Troposphere observations from an European ground-based FTIR network), six ground-based stations in Western Europe, from 79° N to 28° N, all equipped with Fourier Transform infrared (FTIR) instruments and part of the Network for the Detection of Atmospheric Composition Change (NDACC), have joined their efforts to evaluate the trends of several direct and indirect greenhouse gases over the period 1995–2004. The retrievals of CO, CH4, C2H6, N2O, CHClF2, and O3 have been optimized. Using the optimal estimation method, some vertical information ...


Dissociation From The Oligomeric State Is The Rate-Limiting Step In Fibril Formation By Kappa-Casein, Heath Ecroyd, Tomas Koudelka, David Thorn, Danielle M. Williams, Glyn Devlin, Peter Hoffmann, John A. Carver Jan 2008

Dissociation From The Oligomeric State Is The Rate-Limiting Step In Fibril Formation By Kappa-Casein, Heath Ecroyd, Tomas Koudelka, David Thorn, Danielle M. Williams, Glyn Devlin, Peter Hoffmann, John A. Carver

Faculty of Science - Papers (Archive)

Amyloid fibrils are aggregated and precipitated forms of protein in which the protein exists in highly ordered, long, unbranching threadlike formations that are stable and resistant to degradation by proteases. Fibril formation is an ordered process that typically involves the unfolding of a protein to partially folded states that subsequently interact and aggregate through a nucleation-dependent mechanism. Here we report on studies investigating the molecular basis of the inherent propensity of the milk protein, kappa-casein, to form amyloid fibrils. Using reduced and carboxymethylated kappa-casein ( RCM kappa-CN), we show that fibril formation is accompanied by a characteristic increase in thioflavin T ...


High Resolution Analysis Of Uranium And Thorium Concentration As Well As U-Series Isotope Distributions In A Neanderthal Tooth From Payre (Ardeche, France) Using Laser Ablation Icp-Ms, R. Grun, Maxime Aubert, Renaud C. Joannes-Boyau, M-H Moncel Jan 2008

High Resolution Analysis Of Uranium And Thorium Concentration As Well As U-Series Isotope Distributions In A Neanderthal Tooth From Payre (Ardeche, France) Using Laser Ablation Icp-Ms, R. Grun, Maxime Aubert, Renaud C. Joannes-Boyau, M-H Moncel

Faculty of Science - Papers (Archive)

We have mapped U (238U) and Th (232Th) elemental concentrations as well as U-series isotope distributions in a Neanderthal tooth from the Middle Palaeolithic site of Payre using laser ablation ICP-MS. The U-concentrations in an enamel section varied between 1 and 1500 ppb. The U-concentration maps show that U-migration through the external enamel surface is minute, the bulk of the uranium having migrated internally via the dentine into the enamel. The uranium migration and uptake is critically dependent on the mineralogical structure of the enamel. Increased U-concentrations are observed along lineaments, some of which are associated with cracks, and others ...


Ti-In-Zircon Thermometry Applied To Contrasting Archean Metamorphic And Igneous Systems, Joe Hiess, Allen Phillip Nutman, Vickie C. Bennett, Peter Holden Jan 2008

Ti-In-Zircon Thermometry Applied To Contrasting Archean Metamorphic And Igneous Systems, Joe Hiess, Allen Phillip Nutman, Vickie C. Bennett, Peter Holden

Faculty of Science - Papers (Archive)

Ti-in-zircon thermometry with SHRIMP II multi-collector has been applied to two well-documented Archean igneous and metamorphic samples from southern West Greenland. Zircons from 2.71 Ga partial melt segregation G03/38 formed in a small (<1 >m(3)), closed system within a mafic rock under high pressure granulite facies conditions. Results of 14 Ti analyses present a mean apparent zircon crystallization temperature of 679 +/- 11 degrees C, underestimating independent garnet-clinopyroxene thermometry by 20-50 degrees C but consistent with reduced a(TiO2) in this system. 36 spot analysis on 15 zircons from 3.81 Ga meta-tonalite G97/18, with an estimated magmatic ...


The Nagssugtoqidian Orogen In South-East Greenland: Evidence For Paleoproterozoic Collision And Plate Assembly, Allen Phillip Nutman, Feiko Kalsbeek, Clark R L Friend Jan 2008

The Nagssugtoqidian Orogen In South-East Greenland: Evidence For Paleoproterozoic Collision And Plate Assembly, Allen Phillip Nutman, Feiko Kalsbeek, Clark R L Friend

Faculty of Science - Papers (Archive)

The 200 km wide, east-west trending Paleoproterozoic mobile belt of the Ammassalik region of South-East Greenland contains a diverse assemblage of Paleoproterozoic and Archean rocks, variably affected by Paleoproterozoic deformations and high-grade low or high pressure metamorphism. By using previous field and geochemical data combined with new zircon dating and zircon trace element geochemistry, this mobile belt is confirmed as a 1870 to 1840 Ma collisional orogen, which contains one or more 1900 to 1880 Ma magmatic suites and northern and southern Archean basement terranes. The most studied 1900 to 1880 Ma magmatic suite is the Ammassalik Intrusive Complex, which ...


Fluorescence Intensity And Lifetime Imaging Of Free And Micellar-Encapsulated Doxorubicin In Living Cells, X Dai, Zhilian Yue, M E Eccleston, J Swartling, N K H Slater, C F Kaminski Jan 2008

Fluorescence Intensity And Lifetime Imaging Of Free And Micellar-Encapsulated Doxorubicin In Living Cells, X Dai, Zhilian Yue, M E Eccleston, J Swartling, N K H Slater, C F Kaminski

Faculty of Science - Papers (Archive)

Frequency domain fluorescence lifetime imaging microscopy (FLIM) has been used in combination with laser scanning confocal microscopy to study the cellular uptake behavior of the antitumor drug doxorubicin (DOX) and micellar-encapsulated DOX (PLyAd-DOX). The endocytosis uptake process of PLyAd-DOX was monitored over 72 hours using confocal microscopy, with a maximum fluorescence recorded at incubation periods around 24 hours. The micellar structure was not found to release the encapsulated DOX during the time course of imaging. FLIM revealed single lifetime distributions of PLyAd-DOX during accumulation in the cytoplasm. The free DOX in contrast was observed both in the cytoplasm and the ...


Measurement Of Methanol Emissions From Australian Wildfires By Ground-Based Solar Fourier Transform Spectroscopy, Clare Paton-Walsh, Stephen R. Wilson, N. B. Jones, D. W. T. Griffith Jan 2008

Measurement Of Methanol Emissions From Australian Wildfires By Ground-Based Solar Fourier Transform Spectroscopy, Clare Paton-Walsh, Stephen R. Wilson, N. B. Jones, D. W. T. Griffith

Faculty of Science - Papers (Archive)

We report the first atmospheric column measurements of methanol made by ground-based solar Fourier transform infrared spectroscopy. The measurements were made through smoke plumes over South Eastern Australia during the Austral summers of 2001/2002 and 2002/2003. There is a strong correlation between the measured column amounts of methanol and simultaneous and co-located measurements of aerosol optical depth. An emission factor for methanol from Australian forest fires of 2.3 ± 0.8 grams per kilogram of dry fuel consumed is estimated by use of the correlations of methanol and carbon monoxide with aerosol optical depth and literature values for ...


The Holocene Paleo-Tsunami History Of West Australia, S. R. Scheffers, A. Scheffers, D. Kelletat, Edward A. Bryant Jan 2008

The Holocene Paleo-Tsunami History Of West Australia, S. R. Scheffers, A. Scheffers, D. Kelletat, Edward A. Bryant

Faculty of Science - Papers (Archive)

West Australian coastlines experienced several tsunamis in mid-Holocene times. To expand our knowledge about Holocene tsunami events in West Australia, the authors extended the previously studied spatial scale to include the central- and south-western coastlines. Several of the discovered events were mid- and young Holocene (≤1000 yr BP) tsunami impacts on the outer coast of the Cape Range Peninsula. Five hundred kilometres to the south between Cape Cuvier and Point Quobba, additional tsunami evidence exists on top of steep cliffs over a coastal stretch of 30 km. The sedimentary signature of two tsunamis is documented in this area by wide ...