Physical Sciences and Mathematics Commons^™

Pubertal And Adult Leydig Cell Function In Mullerian Inhibiting Substance-Deficient Mice, Xiufeng Wu, Ramamani Arumugam, Stephen Baker, Mary Lee

Mary M. Lee

Mullerian inhibiting substance (MIS) causes Mullerian duct regression during sexual differentiation and regulates postnatal Leydig cell development. MIS knockout (MIS-KO) mice with targeted deletions of MIS develop Leydig cell hyperplasia, but their circulating androgen concentrations are reportedly unaltered. We compared reproductive hormone profiles, androgen biosynthesis, and the expression of key steroidogenic and metabolic enzymes in MIS-KO and wild-type (WT) mice at puberty (36 d) and sexual maturity (60 d). In pubertal animals, basal testosterone and LH concentrations in plasma were lower in MIS-KO than WT mice, whereas human chorionic gonadotropin-stimulated testosterone concentrations were similar. In adults, basal LH, and both …

Characterization Of A Recently Purified Thermophilic Dnase From A Novel Thermophilic Fungus, Kyle Landry, Robert Levin

Kyle S Landry

The Orientation Of Strophomenid Brachiopods On Soft Substrates, Roy Plotnick, Benjamin Dattilo, Daniel Piquard, Jennifer Bauer, Joshua Corrie

Benjamin F. Dattilo

Strophomenid brachiopods have long been interpreted as ‘‘snowshoe’’ strategists, with their flattened concavoconvex valves providing resistance to foundering in very soft sediments. There has been a sharp difference of opinion in whether the shells were oriented with their convex or their concave surface in contact with the sediment. This study, along with independent evidence from sedimentology, ichnology, and morphology, indicates that the strophomenids lived with their shells concave down (convex up). Experiments indicate the force required to push shells into soft cohesive muds is much greater for the convex up than for the convex down orientation. Forces also increase with …

Crystal Structure And Functional Assignment Of Yfau, A Metal Ion Dependent Class Ii Aldolase From Escherichia Coli K12, Dean Rea, Rebecca Hovington, John Rakus, John Gerlt, Vilmos Fu¨Lo¨P, Timothy Bugg, David Roper

John F. Rakus

One of the major challenges in the postgenomic era is the functional assignment of proteins using sequence- and structure-based predictive methods coupled with experimental validation. We have used these approaches to investigate the structure and function of theEscherichia coli K-12 protein YfaU, annotated as a putative 4-hydroxy-2-ketoheptane-1,7-dioate aldolase (HpcH) in the sequence databases. HpcH is the final enzyme in the degradation pathway of the aromatic compound homoprotocatechuate. We have determined the crystal structure of apo-YfaU and the Mg2+−pyruvate product complex. Despite greater sequence and structural similarity to HpcH, genomic context suggests YfaU is instead a 2-keto-3-deoxy sugar aldolase like the …

Stratigraphic Distribution And Suggested Evolution Of Dendroid Graptolites From The Silurian Of Eastern Australia, Barrie Rickards, Anthony Wright

Anthony Wright

Five evolutionary lineages are proposed for Silurian species of the benthic dendroid graptolite genus Dictyonema, based largely on the exceptional eastern Australian records of the genus, comprising at least 25 species. These are: A, the delicatulum lineage with bifurcating ventral autothecal apertural spines; B, the paululum lineage with single ventral apertural spines or processes; C, the elegans lineage with isolated thecal apertures ± processes; D, the sherrardae lineage with dorsal apertural processes; and E, the venustum lineage with simple autothecal apertures. Brief comments are also made on other dendroid genera occurring in Australian strata, namely: Acanthograptus, Koremagraptus, Callograptus, Dendrograptus, Stelechocladia, …

Development Of A Novel Affinity Membrane Purification System For Deoxyribonuclease, Kyle Landry, Robert Levin

Kyle S Landry

The Evolution Of Billfish, Andrew Blitman

Andrew Blitman

No abstract provided.

Insights Into The Cation Permeation Pathway Of Channelrhodopsin-2, Robert Dempski, Ryan Richards

Robert E. Dempski

Channelrhodopsin-2 (ChR2) is a light-activated, non-selective cation channel endogenous to the green algae Chlamydomonas reinhardtii. The unique properties of ChR2 have made it a useful tool in the field of optogenetics. However, the mechanism of ion conductance is not well resolved. Elucidation of the crystal structure of the channelrhodopsin chimera C1C2 has provided structural insight on the putative ChR2 ion conductance pathway. However, it is not clear how the chimeric structure correlates to ChR2 function.

Purification Of An Inducible Dnase From A Thermophilic Fungus, Kyle Landry, Andrea Vu, Robert Levin

Kyle S Landry

Purification And Characterization Of Iso-Ribonucleases From A Novel Thermophilic Fungus, Kyle Landry, Robert Levin

Kyle S Landry

Synthesis Of Novel Sugar Diamino Acids, M Thillakan, A Katsifis, D Skropeta

Danielle Skropeta

Sugar amino acids (SAAs) are found in nature as good construction elements for the preparation of peptide mimetics and oiigosaccharides in drug design and development. The synthesis of SAAs is readily accomplished in few steps and more than 40 SAAs have been synthesised to date.2 Sugar amino acids with an additional amino group, the sugar diamino acid (SDAs) would represent a useful expansion to the library of SAAs available because one of the amino group and carboxylic acid is available for peptide coupling and the another amino/azide group allow to do further derivatisation via peptide or click chemistry such as …

Exploring Marine Resources For New Pharmaceutical Applications, Danielle Skropeta

Danielle Skropeta

No abstract provided.

Valuing Water: Variability And The Lake Eyre Basin, Central Australia, Leah Gibbs

Leah Maree Gibbs

'Environmental values' form an increasingly important component of natural resource management, but use of the term 'value' is dominated by a narrow and limiting utility-based definition. In this paper I consider theories of value and practices of valuing water in the arid and semi-arid Lake Eyre Basin, central Australia. While value is the subject of diverse meanings - both within a range of academic disciplines and as understood by people in specific places - methods of valuing water in natural resource management are limited by reductionism, anthropocentrism and cultural specificity. This conceptualisation of value does not adequately capture what people …

Parcel Subdivision Automation For Agent-Based Land Use Modelling, Rohan Wickramasuriya, Laurie Chisholm, Marji Puotinen, Nicholas Gill, Peter Klepeis

Rohan Wickramasuriya, Ph.D.

To a significant extent rural Australia is transforming into multifunctional landscapes. Amenity migration (i.e. movement of people from metropolitan to rural settings) is a major driving force of this transition in many areas. However, the effects of amenity migration on the receiving landscapes are not yet fully understood. Agent-based land use modelling helps unravel the complex spatio-temporal relationships that affect landscape response to change from amenity migration. A land subdivision module is essential for a complete agent-based land use model developed for these landscapes because the land sold to in-migrants are lots that are subdivided from much larger tracts. In …

Doing Participatory Action Research And Doing A Phd: Words Of Encouragement For Prospective Students, Natascha Klocker

Natascha Klocker

No abstract provided.

Late Quaternary Aeolian And Fluvial Interactions On The Cooper Creek Fan And The Association Between Linear And Source-Bordering Dunes, Strzelecki Desert, Australia, Timothy Cohen, Gerald Nanson, Joshua Larsen, B. Jones, David Price, Maria Coleman, Tim Pietsch

B. G. Jones

The Innamincka Dome and associated low-gradient fan in the Strzelecki Desert is the product of Cenozoic crustal warping that has aided formation of an extensive array of palaeochannels, source-bordering transverse dunes and superimposed linear dunes. These dunes have impeded the course of Cooper Creek and provided a repository of evidence for Quaternary climate change as well as the interactive processes between transverse and linear dune formation. At Turra, Gidgealpa and sites nearby are extensive fluvial and aeolian sand bodies that date from marine isotope stages (MIS) 8-3 and the Last Glacial Maximum (LGM) and are now surrounded or buried by …

Structural Characterization Of Clusterin-Chaperone Client Protein Complexes, Amy Wyatt, Justin Yerbury, Mark Wilson

Mark R Wilson

Clusterin (CLU) is a potent extracellular chaperone that inhibits protein aggregation and precipitation otherwise caused by physical or chemical stresses (e.g. heat, reduction). This action involves CLU forming soluble high molecular weight (HMW) complexes with the client protein. Other than their unquantified large size, the physical characteristics of these complexes were previously unknown. In this study, HMW CLU-citrate synthase (CS), HMW CLU-fibrinogen (FGN), and HMW CLU-glutathione S-transferase (GST) complexes were generated in vitro, and their structures studied using size exclusion chromatography (SEC), ELISA, SDS-PAGE, dynamic light scattering (DLS), bisANS fluorescence, and circular dichroism spectrophotometry (CD). Densitometry of …

Communication: New Insight Into The Barrier Governing Co2 Formation From Oh + Co, Christopher Johnson, Berwyck Poad, Ben Shen, Robert Continetti

Berwyck L. J. Poad

Despite its relative simplicity, the role of tunneling in the reaction OH + CO → H + CO(2) has eluded the quantitative predictive powers of theoretical reaction dynamics. In this study a one-dimensional effective barrier to the formation of H + CO(2) from the HOCO intermediate is directly extracted from dissociative photodetachment experiments on HOCO and DOCO. Comparison of this barrier to a computed minimum-energy barrier shows that tunneling deviates significantly from the calculated minimum-energy pathway, predicting product internal energy distributions that match those found in the experiment and tunneling lifetimes short enough to contribute significantly to the overall reaction. …

Effect Of Density On The Population Dynamics Of Perognathus Formosus And Its Relationships Within A Desert Ecosystem, R. Chew, F. Turner, Peter August, Bernardo Maza, James Nelson

Peter August

No abstract provided.

Trans-Atlantic Correlation Of Upper Cretaceous Marine Sediments, Marcus Ross, David Fastovsky

David Fastovsky

Upper Cretaceous marine deposits from the Mid-Atlantic region of North America (Delaware, Maryland, and New Jersey) and the Maastricht area (southern Netherlands, and nearby Belgium and Gennany) are correlated across the Atlantic using a variety of macro invertebrates, nannofossils, and sequence stratigraphy. Four late Cretaceous Mid-Atlantic sequences, the Marshalltown, Englishtown, Merchantville, and Navesink, span the upper Santonian to lowennost Danian, and have direct correlatives in the Maastricht area. Correlations between the Mid-Atlantic and the Maastricht regions (respectively) are as follows: the upper Santonian to lower Campanian Merchantville and Matawan formations with the Achen and lower Vaals fonnations; the middle Campanian …

Optically Stimulated Luminescence (Osl) Dating Of Perenially Frozen Deposits In North-Central Siberia: Osl Characteristics Of Quartz Grains And Methodological Considerations Regarding Their Suitability For Dating, Lee Arnold, Richard Roberts

Richard G Roberts

Optically stimulated luminescence (OSL) dating of coarse-grained quartz is increasingly being used as the main chronological tool in late Quaternary palaeoenvironmental reconstructions of Siberia. However, relatively little information has been published on the suitability of OSL dating for the various types of perennially frozen sediments found in this region. Here we provide a systematic examination of the quartz luminescence characteristics of 21 perennially frozen samples from the Taimyr Peninsula and adjacent coastal lowlands of north-central Siberia, and discuss their implications for the reliability of single-grain and multi-grain OSL chronologies in such contexts. The results of this study suggest that the …

Development Of The Sar Tt-Osl Procedure For Dating Middle Pleistocene Dune And Shallow Marine Deposits Along The Southern Cape Coast Of South Africa, Zenobia Jacobs, Richard Roberts, Terry Lachlan, Panagiotis Karkanas, Curtis Marean, David Roberts

Richard G Roberts

Optically stimulated luminescence (OSL) dating is now commonly used to estimate the depositional age of Quaternary landforms along the southern Cape coast of South Africa. Due to the early onset of dose saturation in the quartz-rich sediments from this region, determining the age of deposits much older than the last three glacio-eustatic sea-level high stands has been a challenge. In this study, we explored the feasibility of using the thermally-transferred OSL (TT-OSL) dating method to obtain ages for aeolian and shallow marine deposits at three different localities that hold promise to further illuminate the long and complex Late Quaternary sea-level …

Middle Paleolithic Occupation On A Marine Isotope Stage 5 Lakeshore In The Nefud Desert, Saudi Arabia, Michael Petraglia, Abdullah Alsharekh, Remy Crassard, Nick Drake, Huw Groucutt, Adrian Parker, Richard Roberts

Richard G Roberts

No abstract provided.

Dirt, Dates And Dna:Osl And Radiocarbon Chronologies Of Perenially Frozen Sediments In Siberia, And Their Implications For Sedimentary Ancient Dna Studies, Lee Arnold, Richard Roberts, Ross Macphee, James Haile, Fiona Brock, Per Moller, Duane Froese, Alexei Tikhonov, Allan Chivas, M. Thomas Gilbert, Eske Willerslev

Richard G Roberts

The sedimentary ancient DNA (sedaDNA) technique offers a potentially invaluable means of investigating species evolution and extinction dynamics in high-latitude environments. An implicit assumption of the sedaDNA approach is that the extracted DNA is autochthonous with the host deposit and that it has not been physically transported from older source deposits or reworked within the sedimentary profile by postdepositional mixing. In this paper we investigate whether these fundamental conditions are upheld at seven perennially frozen wetland sites across the Taimyr Peninsula and coastal lowlands of north-central Siberia. Optically stimulated luminescence (OSL) and radiocarbon (14C) dating are used to constrain the …

Late Acheulean Hominins At The Marine Isotope Stage 6/5e Transition In North-Central India, Michael Haslam, Richard Roberts, Ceri Shipton, J Pal, Jacqueline Fenwick, Peter Ditchfield, Nicole Boivin, A Dubey, M Gupta, Michael Petraglia

Richard G Roberts

Single-grain optically stimulated luminescence dating was applied to Late Quaternary sediments at two sites in the Middle Son Valley, Madhya Pradesh, India. Designated Bamburi 1 and Patpara, thesse sites contain Late Acheulean stone tool assemblages, which we associate with non-modern hominins. Age determinations of 140-120. ka place the formation of these sites at around the Marine Oxygen Isotope Stage 6-5 transition, placing them among the youngest Acheulean sites in the world. We present here the geochronology and sedimentological setting of these sites, and consider potential implications of Late Pleistocene archaic habitation in north-central India for the initial dispersal of modern …

Mapping Same-Sex Couple Family Households In Australia, Andrew Gorman-Murray, Christopher Brennan-Horley, Kirsten Mclean, Gordon Waitt, Christopher Gibson

Christopher R Brennan-Horley

The map (1:1,218,987) accompanying this report is the first to depict the distribution of same-sex couple family households across Australia. The map and the report contribute to emerging scholarship combining critical geographies of sexualities with quantitative techniques and GIS in order to advance the political claims of sexual minorities. The data were collected through the 2006 Census and obtained via consultation with the Australian Bureau of Statistics. These data included the number of same-sex couple family households for all Statistical Divisions across Australia and for Statistical Sub-Divisions within metropolitan capital cities. Geographical concentrations of same-sex couple family households were determined …

Molluscan Remains From Fiji, Katherine Szabo

Katherine A Szabo

Shell recovered from archaeological sites can give valuable insight to issues of site formation, taphonomy, subsistence, the nature of the environment and environmental change over time. Here, I present a series of shell analyses that can assist in the investigation of several research issues, focusing primarily on ecological issues.

Sharing A Vision For Biodiversity Conservation And Agriculture, John Quinn

John E Quinn

No abstract provided.

Defining Adequate Means Of Residents To Prepare Property For Protection From Wildfire, Trent Penman, Christine Eriksen, R Blanchi, M Chladil, A Gill, K Haynes, Justin Leonard, Jim Mclennan, Ross Bradstock

Christine Eriksen

Wildfire can result in significant loss of property and lives. Evidence shows that residents can decrease the risk of loss when they stay to defend their property. In order to safely defend a property, residents need to be adequately prepared for the wildfire conditions they face. Residents who wish to evacuate prior to the arrival of a wildfire also need to prepare their property and themselves for such an action. Despite the importance of preparation, there are no clear and quantifiable definitions of what it means to be prepared for different exposures to wildfire. Here we develop a model and …

The “Curse Of Rafinesquina:” Negative Taphonomic Feedback Exerted By Strophomenid Shells On Storm-Buried Lingulids In The Cincinnatian Series (Katian, Ordovician) Of Ohio, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Steve Felton, John Pojeta

Benjamin F. Dattilo

Taphonomic feedback is the idea that accumulation of organic remains either enhances the habitat for some organisms (positive taphonomic feedback), and/or degrades the habitat for others (negative taphonomic feedback). Examples of epibionts living on skeletal remains are direct evidence of positive taphonomic feedback. Disruption of infaunal burrowing activities by skeletal fragments is an example of negative taphonomic feedback; direct fossil evidence of this phenomenon has not been documented previously. Infaunal organisms are vulnerable to exhumation or entombment during storms, but organisms that burrow can also re-establish viable life positions subsequently. For example, when modern lingulids re-burrow after exhumation, they first …