Physical Sciences and Mathematics Commons^™

Molecular Characterization Of Escherichia Coli Strains That Cause Symptomatic And Asymptomatic Urinary Tract Infections, Sam Abraham, Toni A. Chapman, Ren Zhang, James Chin, Amanda N. Mabbett, Makrina Totsika, Mark A. Schembri

Faculty of Science - Papers (Archive)

The differences between Escherichia coli strains associated with symptomatic and asymptomatic urinary tract infections (UTIs) remain to be properly determined. Here we examined the prevalence of plasmid types and bacteriocins, as well as genetic relatedness, in a defined collection of E. coli strains that cause UTIs. Comparative analysis identified a subgroup of strains with a high number of virulence genes (VGs) and microcins M/H47. We also identified associations between microcin genes, VGs, and specific plasmid types.

Molecular Dynamics Analysis Of Apolipoprotein-D - Lipid Hydroperoxide Interactions: Mechanism For Selective Oxidation Of Met-93, Aaron J. Oakley, Surabhi Bhatia, Heath Ecroyd, Brett Garner

Faculty of Science - Papers (Archive)

Background: Recent studies suggest reduction of radical-propagating fatty acid hydroperoxides to inert hydroxides by interaction with apolipoprotein-D (apoD) Met93 may represent an antioxidant function for apoD. The nature and structural consequences of this selective interaction are unknown.

Methodology/Principal Findings: Herein we used molecular dynamics (MD) analysis to address these issues. Longtimescale simulations of apoD suggest lipid molecules are bound flexibly, with the molecules free to explore multiple conformations in a binding site at the entrance to the classical lipocalin ligand-binding pocket. Models of 5s- 12s- and 15s hydroperoxyeicosatetraenoic acids were created and the lipids found to wrap around Met93 thus …

Characterization Of Gellan Gum By Capillary Electrophoresis, Danielle L. Taylor, Cameron J. Ferris, Alison R. Maniego, Patrice Castignolles, Marc In Het Panhuis, Marianne Gaborieau

Faculty of Science - Papers (Archive)

Gellan gums were characterised for the first time using free-solution capillary electrophoresis (CE) or CE under critical conditions (CE-CC). CE-CC is a fast method that separates the polysaccharide. Gellan gums are shown to be heterogeneous in terms of their electrophoretic mobility at 55°C revealing: oligomer peak(s), broad peaks of polymers with a random coil conformation with different degrees of acylation (composition), aggregates, and polymers with double-helix conformation. CE-CC is complementary with the rheological analysis also performed in this work. Sonication of gellan gums is shown to decrease the viscosity of gellan gum mainly by breaking up aggregates. The effect of …

Self-Assembled Gels From Biological And Synthetic Polyelectrolytes, Paul Calvert, Skander Limem, Don Mccallum, Gordon G. Wallace, Marc In Het Panhuis

Faculty of Science - Papers (Archive)

Inkjet printing of alternate layers of anionic and cationic polyelectrolytes allows organized gels to form with structures similar to those made by layer--by-layer dipping methods but very much faster. Structures of gels formed using slow and fast inkjet printing systems are compared using elemental analysis, swelling and diffusion kinetics as characterization methods. After printing and washing, most sodium or chloride counter-ions are last from the gel, leave only the polymer complex. The swelling properties of the printed and washed gel depend on the deposition rate and on the ratio of the two polymers as originally printed. The synthetic polyelectrolytes reported …

Fragment-Based Screening By Protein Crystallography: Successes And Pitfalls, Zorik Chilingaryan, Zhou Yin, Aaron J. Oakley

Faculty of Science - Papers (Archive)

Fragment-based drug discovery (FBDD) concerns the screening of low-molecular weight compounds against macromolecular targets of clinical relevance. These compounds act as starting points for the development of drugs. FBDD has evolved and grown in popularity over the past 15 years. In this paper, the rationale and technology behind the use of X-ray crystallography in fragment based screening (FBS) will be described, including fragment library design and use of synchrotron radiation and robotics for high-throughput X-ray data collection. Some recent uses of crystallography in FBS will be described in detail, including interrogation of the drug targets β-secretase, phenylethanolamine N-methyltransferase, phosphodiesterase …

Competition Strength Of Two Significant Invasive Species In Coastal Dunes, K French

Faculty of Science - Papers (Archive)

To investigate the effect of increased nutrient availability on competition amongst invasive and native plants, I measured changes in above and below ground biomass of Chrysanthemoides monilifera spp. rotundata (bitou bush) and Asparagus aethiopicus (asparagus fern) competing with two native species, Banksia integrifolia and Ficinia nodosa, under highand low-nutrient regimes. Bitou bush, as a primary invader, was competitive under all conditions lowering the growth of native species in both high and low nutrients. Asparagus fern as a secondary invader, did not influence growth of native species but responded, like bitou bush, to high nutrients. Native species were generally negatively …

A Fourier Transform Infrared Trace Gas And Isotope Analyser For Atmospheric Applications, D W. T Griffith, N M. Deutscher, C Caldow, G Kettlewell, M Riggenbach, S Hammer

Faculty of Science - Papers (Archive)

Concern in recent decades about human impacts on Earth's climate has led to the need for improved and expanded measurement capabilities of greenhouse gases in the atmosphere. In this paper we describe in detail an in situ trace gas analyser based on Fourier Transform Infrared (FTIR) spectroscopy that is capable of simultaneous and continuous measurements of carbon dioxide (CO₂), methane (CH₄), carbon monoxide (CO), nitrous oxide (N₂O) and ¹³C in CO₂ in air with high precision. High accuracy is established by reference to measurements of standard reference gases. Stable water isotopes can …

Becoming Differently Modern: Geographic Contributions To A Generative Climate Politics, Lesley M. Head, Christopher R. Gibson

Faculty of Science - Papers (Archive)

Anthropogenic climate change is a quintessentially modern problem in its historical origins and discursive framing, but how well does modernist thinking provide us with the tools to solve the problems it created? On one hand even though anthropogenic climate change is argued to be a problem of human origins, solutions to which will require human actions and engagements, modernity separates people from climate change in a number of ways. On the other, while amodern or more-than-human concepts of multiple and relational agency are more consistent with the empirical evidence of humans being deeply embedded in earth surface processes, these approaches …

Gas-Particle Partitioning Of Atmospheric Hg(Ii) And Its Effect On Global Mercury Deposition, H M. Amos, D J. Jacob, C D. Holmes, Jenny A. Fisher, Q Wang, R M. Yantosca, E S. Corbitt, E Galarneau, A P. Rutter, M S. Gustin, A Steffen, J J. Schauer, J A. Graydon, V L. St Louis, R W. Talbot, E S. Edgerton, Y Zhang, E N. Sunderland

Faculty of Science - Papers (Archive)

Atmospheric deposition represents a major input of mercury to surface environments. The phase of mercury (gas or particle) has important implications for its removal from the atmosphere. We use long-term observations of reactive gaseous mercury (RGM), particle-bound mercury (PBM), fine particulate matter (PM_2.5), and temperature at five sites in North America to derive an empirical gas-particle partitioning relationship log₁₀(K^-1) = (10 ± 1) − (2500 ± 300)/T where K = (PBM/PM_2.5)/RGM with PBM and RGM in common mixing ratio units, PM_2.5 in μg m⁻³, and T in …

Soil Chemistry: Understanding Phosphorus In The Environment, Paul Milham, Warwick Dougherty, Robert John Morrison, Robert Graham Clark, Ronald Smernik, Ashlea Doolette, Lucy Burkitt, Damian Collins, Rebeca Alvarez, Andrew Thomas

Faculty of Science - Papers (Archive)

It is an essential ingredient in food production, but poor management means bad news downstream. Understanding the way phosphorus behaves in the environment calls for soil and plant biology, and some new soil chemistry.

Australia's Black Saturday Fires - Comparison Of Techniques For Estimating Emissions From Vegetation Fires, Clare Paton-Walsh, Louisa K. Emmons, Christine Wiedinmyer

Faculty of Science - Papers (Archive)

We present a comparison of techniques for estimating atmospheric emissions from fires using Australia's 2009 "Black Saturday" wildfires as a case study. Most of the fires started on Saturday the 7th of February 2009 (a date now known as "Black Saturday") and then spread rapidly, fanned by gale force winds, creating several firestorms and killing 173 people. The fires continued into early March, when rain and cooler conditions allowed the fires to be extinguished. In this study, we compare two new techniques (and one more established method) to estimate the total emissions of a number of atmospheric trace gases from …

Evidence Of Enso Mega-Drought Triggered Collapse Of Prehistory Aboriginal Society In Northwest Australia, Hamish Mcgowan, Samuel K. Marx, P Moss, Andrew Hammond

Faculty of Science - Papers (Archive)

The Kimberley region of northwest Australia contains one of the World's largest collections of rock art characterised by two distinct art forms; the fine featured anthropomorphic figures of the Gwion Gwion or Bradshaw paintings, and broad stroke Wandjina figures. Luminescence dating of mud wasp nests overlying Gwion Gwion paintings has confirmed an age of at least 17,000 yrs B.P. with the most recent dates for these paintings from around the mid-Holocene (5000 to 7000 yrs B.P.). Radiocarbon dating indicates that the Wandjina rock art then emerged around 3800 to 4000 yrs B.P. following a hiatus of at least 1200 yrs. …

Dissociation Of Erk Signalling Inhibition From The Anti-Amyloidogenic Action Of Synthetic Ceramide Analogues, Hongyun Li, Genevieve Evin, Andrew F. Hill, Ya Hui Hung, Ashley I. Bush, Brett Garner

Faculty of Science - Papers (Archive)

Inhibition of GSL (glycosphingolipid) synthesis reduces Aβ (amyloid β-peptide) production in vitro. Previous studies indicate that GCS (glucosylceramide synthase) inhibitors modulate phosphorylation of ERK1/2 (extracellular-signal-regulated kinase 1/2) and that the ERK pathway may regulate some aspects of Aβ production. It is not clear whether there is a causative relationship linking GSL synthesis inhibition, ERK phosphorylation and Aβ production. In the present study, we treated CHO cells (Chinese-hamster ovary cells) and SH-SY5Y neuroblastoma cells, that both constitutively express human wild-type APP (amyloid precursor protein) and process this to produce Aβ, with GSL-modulating agents to explore this relationship. We found that three …

Telomere Dynamics And Homeostasis In A Transmissible Cancer, Beata Ujvari, Anne-Maree Pearse, Robyn Taylor, Stephen Pyecroft, Cassandra Flanagan, Sara Gombert, Anthony T. Papenfuss, Thomas R. Madsen, Katherine Belov

Faculty of Science - Papers (Archive)

Background: Devil Facial Tumour Disease (DFTD) is a unique clonal cancer that threatens the world's largest carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii) with extinction. This transmissible cancer is passed between individual devils by cell implantation during social interactions. The tumour arose in a Schwann cell of a single devil over 15 years ago and since then has expanded clonally, without showing signs of replicative senescence; in stark contrast to a somatic cell that displays a finite capacity for replication, known as the "Hayflick limit". Methodology/Principal Findings: In the present study we investigate the role of telomere length, measured as …

The Relationship Between Particulate Pollution Levels In Australian Cities, Meteorology, And Landscape Fire Activity Detected From Modis Hotspots, Owen F. Price, Grant J. Williamson, Sarah B. Henderson, Fay Johnston, David M. J. S Bowman

Faculty of Science - Papers (Archive)

Generally, sigmoid curves are used to describe the growth of animals over their lifetime. However, because growth rates often differ over an animal's lifetime a single curve may not accurately capture the growth. Broken-stick models constrained to pass through a common point have been proposed to describe the different growth phases, but these are often unsatisfactory because essentially there are still two functions that describe the lifetime growth. To provide a single, converged model to age animals with disparate growth phases we developed a smoothly joining two-phase nonlinear function (SJ2P), tailored to provide a more accurate description of lifetime growth …

From Ecophysiology To Phenomics: Some Implications Of Photoprotection And Shade-Sun Acclimation In Situ For Dynamics Of Thylakoids In Vitro, Shizue Matsubara, Britta Forster, Melinda Waterman, Sharon A. Robinson, Barry J. Pogson, Brian Gunning, Barry Osmond

Faculty of Science - Papers (Archive)

Half a century of research into the physiology and biochemistry of sun–shade acclimation in diverse plants has provided reality checks for contemporary understanding of thylakoid membrane dynamics. This paper reviews recent insights into photosynthetic efficiency and photoprotection from studies of two xanthophyll cycles in old shade leaves from the inner canopy of the tropical trees Inga sapindoides and Persea americana (avocado). It then presents new physiological data from avocado on the time frames of the slow coordinated photosynthetic development of sink leaves in sunlight and on the slow renovation of photosynthetic properties in old leaves during sun to shade and …

Phytochemical And Biological Activity Studies Of The Bhutanese Medicinal Plant Corydalis Crispa, Phurpa Wangchuk, Paul A. Keller, Stephen G. Pyne, Thanapat Sastraruji, Malai Taweechotipatr, Roonglawan Rattanajak, Aunchalee Tonsomboon, Sumalee Kamchonwongpaisan

Faculty of Science - Papers (Archive)

The chemical constituents and biological activities of Corydalis crispa (Fumariaceae) were investigated for the first time. The phytochemical study resulted in the isolation of nine known isoquinoline alkaloids: protopine (1), 13-oxoprotopine (2), 13-oxocryptopine (3), stylopine (4), coreximine (5), rheagenine (6), ochrobirine (7), sibiricine (8) and bicuculline (9), with complete NMR data for 2 and 3 provided here for the first time. Crude extracts exhibitedsignificant anti-inflammatory (p < 0.01) activity against TNF-alpha production in LPS activated THP-1 cells. The acetylcholinesterase inhibitory activity of compounds 2, 4 and 7 and the antiplasmodial activity of compound 5 against P. falciparum strains TM4/8.2 and K1CB1 (multidrug resistant strain) are reported here for the first time. Stylopine (4) did not show antimalarial activity against the K1CB1 strain in contrast to a previous report. This study generated a scientific basis for the use of this plant in Bhutanese traditional medicine, either individually or in combination with other medicinal ingredients to treat a broad range of disorders. This study also identified compound 5 as potential new antimalarial lead compound.

Observed And Simulated Time Evolution Of Hcl, Clono2, And Hf Total Column Abundances, R Kohlhepp, R Ruhnke, M P Chipperfield, M De Maziere, J Notholt, S Barthlott, R L. Batchelor, R D. Blatherwick, Th Blumenstock, M T. Coffey, P Demoulin, H Fast, W Feng, A Goldman, D W. T Griffith, K Hamann, J W. Hannigan, F Hase, N B. Jones, A Kagawa, I Kaiser, Y Kasai, O Kirner, W Kouker, R Lindenmaier, E Mahieu, R L. Mittermeier, B Monge-Sanz, I Morino, I Murata, H Nakajima, M Palm, Clare Paton-Walsh, U Raffalski, Th Reddmann, M Rettinger, C P. Rinsland, E Rozanov, M Schneider, C Senten, C Servais, B M. Sinnhuber, D Smale, K Strong, R Sussmann, J R. Taylor, G Vanhaelewyn, T Warneke, C Whaley, M Wiehle, S W. Wood

Faculty of Science - Papers (Archive)

Time series of total column abundances of hydrogen chloride (HCl), chlorine nitrate (ClONO2), and hydrogen fluoride (HF) were determined from ground-based Fourier transform infrared (FTIR) spectra recorded at 17 sites belonging to the Network for the Detection of Atmospheric Composition Change (NDACC) and located between 80.05° N and 77.82° S. By providing such a near-global overview on ground-based measurements of the two major stratospheric chlorine reservoir species, HCl and ClONO2, the present study is able to confirm the decrease of the atmospheric inorganic chlorine abundance during the last few years. This decrease is expected following the 1987 Montreal Protocol and …

The Geologic Turn: Architecture's New Alliance, Etienne Turpin

SMART Infrastructure Facility - Papers

Recent research and practice in the fields of architecture, art, and philosophy suggest the increasing influence of geology with the design disciplines, visual arts, and theoretical humanities. The symposium A Geologic Turn: Architecture's New Alliance, curated by Etienne Turpin, Ph.D., as part of the Sanders Research Fellowship at the Taubman College of Architecture & Urban Planning, University of Michigan, bring together researchers, scholars, and practitioners whose work is at the center of this fecund transdisciplinary trajectory. The objectives of the symposium are to encourage new productive connections among current scholarship and practice, and to expose this new transdisciplanary research to …

Sustained Solar Hydrogen Generation Using A Dye-Sensitised Nio Photocathode/Bivo4 Tandem Photo-Electrochemical Device, Lei Tong, Akihide Iwase, Andrew Nattestad, Udo Bach, Martin Weidelener, Gunther Gotz, Amaresh Mishra, Peter Bauerle, Rose Amal, Gordon G. Wallace, Attila J. Mozer

Faculty of Science - Papers (Archive)

Solar hydrogen generation sustained for at least several hours is demonstrated using a dye-sensitised nickel(II) oxide photocathode and BiVO4 photoanode connected in a tandem configuration. H2 evolution rate is 120 nmol h−1 (>80% faradaic efficiency) without electrical bias or sacrificial oxidant/reductant, at pH = 7 using visible light (>420 nm).

Properties Of The B+-H2 And B+-D2 Complexes: A Theoretical And Spectroscopic Study, B L. J Poad, V Dryza, A A. Buchachenko, J Kos, E J. Bieske

Faculty of Science - Papers (Archive)

The rotationally resolved infrared spectrum of the B+-D2 ion-neutral complex is recorded in the D-D stretch vibration region (2805–2875  cm−1) by detecting B+ photofragments. Analysis of the spectrum confirms a T-shaped equilibrium geometry for the B+-D2 complex with a vibrationally averaged intermolecular bond length of 2.247 Å, around 0.02 Å shorter than for the previously characterised B+-H2 complex [V. Dryza, B. L. J. Poad, and E. J. Bieske, J. Am. Chem. Soc. 130, 12986 (2008)10.1021/ja8018302]. The D-D stretch band centre occurs at 2839.76 ± 0.10 cm−1, representing a −153.8  cm−1 shift from the Q1(0) transition of the free D2 molecule. …

Engaging With The (Un)Familiar: Field Teaching In A Multi-Campus Teaching Environment, Nicholas Gill, Michael Adams, Christine Eriksen

Faculty of Science - Papers (Archive)

Field trips have long been central to geography, but have been subject to assessment of the role of the 'field' in teaching. At the same time, academics face barriers to running field trips. Distance education and enhanced educational access for non-metropolitan students represented such an obstacle at an Australian university. These obstacles were taken as an opportunity to draw on the regional nature of the students and staff to enhance teaching goals, run critically informed field trips by and manage academic workloads. We evaluate the field trips by conducting surveys and interviews with students and tutors, and as an example …

Synthesis Of Stemofoline Analogues As Acetylcholinesterase Inhibitors, Kwankamol Sastraruji, Thanapat Sastraruji, Alison T. Ung, Renate Griffith, Araya Jatisatienr, Stephen G. Pyne

Faculty of Science - Papers (Archive)

Thirty two new stemofoline analogues were prepared from didehydrostemofoline for studies as AChE inhibitors. C-3 side-chain modified amino, carbamate, triazole and oxazole stemofoline derivatives were prepared. In general the amine derivatives were found to be stronger inhibitors of AChE than their alcohol analogues that we previously reported. Compounds 5 and 26, with small C-3 side chain substituents, were two of the most active inhibitors. Preliminary molecular docking studies suggested that these compounds may inhibit AChE by binding horizontally along the passage of the active-site gorge and block access to acetylcholine.

Perceptions Of A Gender-Inclusive Curriculum Amongst Australian Information And Communications Technology Academics, Tony Koppi, Madeleine Roberts, Golshah Naghdy

Faculty of Informatics - Papers (Archive)

The lack of female enrolments in ICT is widely recognised and has prompted a range of strategies to attract more women, most of which do not include curriculum changes at any level. Research suggests that there are aspects of the ICT curriculum that could appeal to females, particularly in relation to benefits to society and humanity in general, and that including these considerations in the curriculum would be of interest to all students. The perceptions of a gender-inclusive ICT curriculum in Australia have been ascertained from a survey and forum discussions of ICT academic managers and leaders of ICT learning …

A Fundamental Analysis Of Continuous Flow Bioreactor And Membrane Reactor Models With Tessier Kinetics, M I. Nelson, E Balakrishnan, H S. Sidhu

Faculty of Informatics - Papers (Archive)

In this research we analyze the steady-state operation of a continuous flow bioreactor, with or without recycle, and an idealized or nonidealized continuous flow membrane reactor. The model extends to include a fixed bed reactor where a fraction of the biomass is detached by the flow. The reaction is assumed to be governed by Tessier growth kinetics. We show that a flow reactor with idealized recycle has the same performance as an idealized membrane reactor and that the performance of a nonidealized membrane reactor is identical to that of an appropriately defined continuous flow bioreactor with nonidealized recycle. The performance …

Boundary Quotients Of The Toeplitz Algebra Of The Affine Semigroup Over The Natural Numbers, Nathan Brownlowe, Astrid An Huef, Marcelo Laca, Iain Raeburn

Faculty of Informatics - Papers (Archive)

No abstract provided.

Integration On Locally Compact Noncommutative Spaces, A L. Carey, V Gayral, Adam C. Rennie, F A. Sukochev

Faculty of Informatics - Papers (Archive)

We present an ab initio approach to integration theory for nonunital spectral triples. This is done without reference to local units and in the full generality of semifinite noncommutative geometry. The main result is an equality between the Dixmier trace and generalised residue of the zeta function and heat kernel of suitable operators. We also examine definitions for integrable bounded elements of a spectral triple based on zeta function, heat kernel and Dixmier trace techniques. We show that zeta functions and heat kernels yield equivalent notions of integrability, which imply Dixmier traceability.

Blacr: Ttp-Free Blacklistable Anonymous Credentials With Reputation, Man Ho Au, Apu Kapadia, Willy Susilo

Faculty of Informatics - Papers (Archive)

Anonymous authentication can give users the license to misbehave since there is no fear of retribution. As a deterrent, or means to revocation, various schemes for accountable anonymity feature some kind of (possibly distributed) trusted third party (TTP) with the power to identify or link misbehaving users. Recently, schemes such as BLAC and PEREA showed how anonymous revocation can be achieved without such TTPs—anonymous users can be revoked if they misbehave, and yet nobody can identify or link such users cryptographically. Despite being the state of the art in anonymous revocation, these schemes allow only a basic form of revocation …

Attribute-Based Oblivious Access Control, Jinguang Han, Willy Susilo, Yi Mu, Jun Yan

Faculty of Informatics - Papers (Archive)

In an attribute-based system (ABS), users are identified by various attributes, instead of their identities. Since its seminal introduction, the attribute-based mechanism has attracted a lot of attention. However, current ABS schemes have a number of drawbacks: (i) the communication cost is linear in the number of the required attributes; (ii) the computation cost is linear in the number of the required attributes and (iii) there are no efficient verification algorithms for the secret keys. These drawbacks limit the use of ABS in practice. In this paper, we propose an attribute-based oblivious access control (ABOAC) scheme to address these problems, …

Dynamical Random-Set Modeling Of Concentrated Precipitation In North America, Noel Cressie, Renato Assuncao, Scott H. Holan, Michael Levine, Orietta Nicolis, Jun Zhang, Jian Zou

Faculty of Informatics - Papers (Archive)

In order to study climate at scales where policy decisions can be made, regional climate models (RCMs) have been developed with much finer resolution (~50 km) than the ~500 km resolution of atmosphere-ocean general circulation models (AOGCMs). The North American Regional Climate Change Assessment Program (NARCCAP) is an international program that provides 50-km resolution climate output for the United States, Canada, and northern Mexico. In Phase I, there are six RCMs, from which we choose one to illustrate our methodology. The RCMs are updated every 3 hours and contain a number of variables, including temperature, precipitation, wind speed, wind direction, …