Physical Sciences and Mathematics Commons^™

36 Degrees Step Size Of Proton-Driven C-Ring Rotation In Fof1-Atp Synthase, Monika Düser, Nawid Zarrabi, Daniel Cipriano, Stefan Ernst, Gary Glick, Stanley Dunn, Michael Börsch

Stanley D Dunn

Synthesis of adenosine triphosphate ATP, the 'biological energy currency', is accomplished by F(o)F(1)-ATP synthase. In the plasma membrane of Escherichia coli, proton-driven rotation of a ring of 10 c subunits in the F(o) motor powers catalysis in the F(1) motor. Although F(1) uses 120 degrees stepping during ATP synthesis, models of F(o) predict either an incremental rotation of c subunits in 36 degrees steps or larger step sizes comprising several fast substeps. Using single-molecule fluorescence resonance energy transfer, we provide the first experimental determination of a 36 degrees sequential stepping mode of the c-ring during ATP synthesis.

Re-Introduction Of Transmembrane Serine Residues Reduce The Minimum Pore Diameter Of Channelrhodopsin-2, Robert Dempski, Ryan Richards

Robert E. Dempski

Channelrhodopsin-2 (ChR2) is a microbial-type rhodopsin found in the green algae Chlamydomonas reinhardtii. Under physiological conditions, ChR2 is an inwardly rectifying cation channel that permeates a wide range of mono- and divalent cations. Although this protein shares a high sequence homology with other microbial-type rhodopsins, which are ion pumps, ChR2 is an ion channel. A sequence alignment of ChR2 with bacteriorhodopsin, a proton pump, reveals that ChR2 lacks specific motifs and residues, such as serine and threonine, known to contribute to non-covalent interactions within transmembrane domains. We hypothesized that reintroduction of the eight transmembrane serine residues present in bacteriorhodopsin, but …

Structural Insights Into Neuronal K+ Channel-Calmodulin Complexes, Karen Mruk, Shivender Shandilya, Robert Blaustein, Celia Schiffer, William Kobertz

Celia A. Schiffer

Calmodulin (CaM) is a ubiquitous intracellular calcium sensor that directly binds to and modulates a wide variety of ion channels. Despite the large repository of high-resolution structures of CaM bound to peptide fragments derived from ion channels, there is no structural information about CaM bound to a fully folded ion channel at the plasma membrane. To determine the location of CaM docked to a functioning KCNQ K(+) channel, we developed an intracellular tethered blocker approach to measure distances between CaM residues and the ion-conducting pathway. Combining these distance restraints with structural bioinformatics, we generated an archetypal quaternary structural model of …

Adaptation To Hard-Object Feeding In Sea Otters And Hominins, Paul Constantino, James Lee, Dylan Morris, Peter Lucas, Adam Hartstone-Rose, Wah-Keat Lee, Nathaniel Dominy, Andrew Cunningham, Mark Wagner, Brian Lawn

Paul J. Constantino

The large, bunodont postcanine teeth in living sea otters (Enhydra lutris) have been likened to those of certain fossil hominins, particularly the ’robust’ australopiths (genus Paranthropus). We examine this evolutionary convergence by conducting fracture experiments on extracted molar teeth of sea otters and modern humans (Homo sapiens) to determine how load-bearing capacity relates to tooth morphology and enamel material properties. In situ optical microscopy and x-ray imaging during simulated occlusal loading reveal the nature of the fracture patterns. Explicit fracture relations are used to analyze the data and to extrapolate the results from humans to earlier hominins. It is shown …

Approaches To Development Of A User-Friendly Community Based Arsenic/Iron Removal Unit In Bangladesh, Khondoker Mahabub Hassan, Farooque Ahmed, Faisal Hai, Saleh Faraj Magram

Faisal I Hai

The present stydy focuses on the strategies to modify the design of a community based Arsenic - Iron Removal Unit (AIRU) based on the field performance of the AIRU and the feedback from the users. The ultimate aim was to offer a user-friendly and sustainable system. Appropriate modifications in the design of the developed unit reduced the propensities of water head-loss and media clogging, thereby yielding sustained flow rate. Introduction of a simple cleaning procerdure (98% flow-recovery with three successive backwashing sequences) successfully reduced the frequency of requirement of labor-intensive replacement of the whole filter media. Raw water with arsenic …

Manufacturing On The Move? Beyond The High Dollar In The Debate About Making Things In Australia - The Case Of The Australian Surfboard Industry - Ausccer Discussion Paper No. 2012/2, Andrew Warren, Chris Gibson

Chris Gibson

In October 2011 surfboard manufacturer BASE abruptly closed its factory on the Gold Coast resulting in the direct loss of 50 jobs. A few days later, nearby D’Arcy Surfboards also announced it was shedding workers and downsizing from a state-of-the art purpose built factory into a backyard workshop. Each business exported surfboards internationally and employed some of Australia’s best known surfboard-makers. The troubles facing these workshops added to those brewing at the very same in Australia’s steel, aluminium, automotive and garment industries. With renewed public debate and media commentary on the future of manufacturing, we now face a crisis in …

Open Access To Stm Information: Trends, Models, And Strategies For Libraries (Review), Steven Van Tuyl

Steven I Van Tuyl

No abstract provided.

Arctic To Outback: Indigenous Rights, Conservation And Tourism, Michael Adams

Michael Adams

Internationally, there has been significant growth in conservation landscapes as a land tenure, since the specific creation of the concept of a “national park” at Yellowstone, USA, in 1872. “Protected areas”, as an umbrella designation for national parks, nature reserves and other forms of conservation landscape, now occupy nearly 13% of the world’s terrestrial area (Chape, Spalding and Jenkins 2008). The early North American, Australian and many other national park systems, while focusing on conservation, explicitly embraced tourism (Boyd and Butler, 2000). However, in the decades since World War II, recreational use of national parks has increased enormously, creating entire …

First Nations And The Politics Of Indigeneity: Australian Perspectives On Indigenous Peoples, Resource Management And Global Rights, R. Lawrence, Michael Adams

Michael Adams

No abstract provided.

Bushfire And Everyday Life: Examining The Awareness-Action 'Gap' In Changing Rural Landscapes, Christine Eriksen, Nicholas Gill

Christine Eriksen

In this paper we use the notion of 'everyday life' to critically examine an apparent 'gap' between bushfire risk awareness and preparedness amongst diverse landholders in rural landscapes affected by amenity-led in-migration in southeast Australia. Landholders were found to bring their own agency to bushfire preparedness in the relationships between everyday procedures, dilemmas, and tradeoffs. Consequently, regardless of landholders' awareness levels, attitudes towards bushfire and natural resource management influence if, how, and to what extent landowners prepare for bushfires. We argue that not only is the 'gap' complex but also paradoxical in that it is both evident in, and constituted …

Indigenous Environmental Knowledge, Christine Eriksen, Michael Adams

Christine Eriksen

No abstract provided.

Water Places: Cultural, Social And More-Than-Human Geographies Of Nature, Leah Gibbs

Leah Maree Gibbs

Cultural, social and more-than-human approaches to nature research are largely held apart in the discipline of human geography. In this paper I argue that these three approaches can be brought together to good effect. The paper presents a situated account of 'water places' in inland Australia-namely the artesian bores, boredrains and boredrain wetlands of the Birdsville Track-in order to demonstrate that together, these three approaches can reveal the complex interactions that form particular places, and comprise a more-than-human world. This account explores the layers of interaction that have formed these water places, including their insertion into the landscape through drilling, …

Learning From The South: Common Challenges And Solutions For Small-Scale Farming, L C Stringer, C Twyman, Leah Gibbs

Leah Maree Gibbs

Small-scale farmers all over the world face a number of common biophysical and socio-economic challenges. In this paper we draw on data from a workshop held in the UK in 2005, to assess whether experiences in addressing these challenges, as gained in the global South, may be used to inform solutions to similar challenges in the UK. In doing so, we contribute to a growing body of literature that seeks to challenge predominantly North-South flows of knowledge and resources. We first identify specific common challenges faced by small-scale farmers in the global North and South. We then compare the different …

Book Review: "Resurrecting The Granary Of Rome: Environmental History And French Colonial Expansion In North Africa" By Diana K. Davis, Leah Gibbs

Leah Maree Gibbs

In this rigorously researched book, Davis argues that French colonisation of the Maghreb (the three North African countries of Morocco, Algeria and Tunisia) was motivated and rationalised by a ‘declensionist environmental narrative’; a narrative that attributed environmental decline to the land use practices of the ‘native’ people of North Africa. Davis begins by questioning the often unquestioned environmental history of North Africa: the ‘sad tale of deforestation and desertification that has spanned much of the past two millennia’. She asserts that this environmental history has been constructed and reworked over time by ‘French colonial scientists, administrators, military men and settlers’.

Contemporary Racism And Islamaphobia In Australia: Racialising Religion, Kevin Dunn, Natascha Klocker, Tanya Salabay

Natascha Klocker

Contemporary anti-Muslim sentiment in Australia is reproduced through a racialization that includes well rehearsed stereotypes of Islam, perceptions of threat and inferiority, as well as fantasies that the Other (in this case Australian Muslims) do not belong, or are absent. These are not old or colour-based racisms, but they do manifest certain characteristics that allow us to conceive a racialization process in relation to Muslims. Three sets of findings show how constructions of Islam are important means through which racism is reproduced. First, public opinion surveys reveal the extent of Islamaphobia in Australia and the links between threat perception and …

Governing Knowledge: Discourses And Tactics Of The European Union In Trade-Related Intellectual Property Negotiations, Daniel Robinson, Christopher Gibson

Chris Gibson

With global shifts in the format of international trade negotiations—frommultilateral to bilateral and regional fora—possibilities for the unequal exercise of power have amplified. At risk are the trade-related interests of “developing” economies, as well as public policy issues like access to medicines. In response we analyse some of the emerging governmental approaches currently being employed for trade-related intellectual property (IP) rules. Our concern is to provide a deeper understanding of the ways power is exercised internationally. Here, we explore the European Union (EU) approaches towards trade negotiations. Examining the role of the EU in IP-related trade negotiations, recent actions towards …

Interaction Of Fish Aryl Hydrocarbon Receptor Paralogs (Ahr1 And Ahr2) With The Retinoblastoma Protein, Rebeka Merson, Sibel Karchner, Mark Hahn

Rebeka Rand Merson

The aryl hydrocarbon receptor (AHR) mediates the toxic effects of 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD) and related compounds. In some mammalian cell lines, TCDD induces G1 cell cycle arrest, which depends on an interaction between the AHR and the retinoblastoma tumor suppressor (RB). Mammals possess one AHR, whereas fishes possess two or more AHR paralogs that differ in the domains important for AHR-RB interactions in mammals. To test the hypothesis that fish AHR paralogs differ in their ability to interact with RB, we cloned RB cDNA from Atlantic killifish, Fundulus heteroclitus, and studied the interactions of killifish RB protein with killifish AHR1 and …

2011 Scholars And Artists Bibliography, Mark Tebeau

Mark Tebeau

This bibliography was created for the annual Friends of the Michael Schwartz Library Scholars and Artists Reception, recognizing scholarly and creative achievements of Cleveland State University faculty, staff and emeriti. Mark Tebeau was the guest speaker

Disparities In Combination Drug Therapy Use In Older Adults With Coronary Heart Disease: A Cross-Sectional Time-Series In A Nationally Representative Us Sample, Jennifer Tjia, Becky Briesacher, Dawei Xie, Jason Fu, Robert Goldberg

Jennifer Tjia

BACKGROUND: Despite evidence of effective combination drug therapy for secondary prevention of coronary heart disease (CHD), older adults with this condition remain undertreated.

OBJECTIVE: To describe time trends (1992-2003) in the adoption of combination cardiac drug therapies (beta-blockers [beta-adrenoceptor antagonists], ACE inhibitors or angiotensin II type 1 receptor antagonists [angiotensin receptor blockers; ARBs], and lipid-lowering agents) among older adults in the US with CHD and to identify factors associated with not using combination therapy.

METHODS: The study took the form of a cross-sectional time-series. The study population consisted of a nationally representative sample of adults aged >or=65 years with CHD …

A New Eusuchian Crocodyliform With Novel Cranial Integument And Its Significance For The Origin And Evolution Of Crocodylia, Casey Holliday, Nicholas Gardner

Nicholas Gardner

Crocodyliforms were one of the most successful groups of Mesozoic tetrapods, radiating into terrestrial, semiaquatic and marine environments, while occupying numerous trophic niches, including carnivorous, insectivorous, herbivorous, and piscivorous species. Among these taxa were the enigmatic, poorly represented flat-headed crocodyliforms from the late Cretaceous of northern Africa. Here we report a new, giant crocodyliform from the early Late Cretaceous (Cenomanian) Kem Kem Formation of Morocco. Represented by a partial braincase, the taxon has an extremely long, flat skull with large jaw and craniocervical muscles. The skull roof is ridged and ornamented with a broad, rough boss surrounded by significant vascular …

The Molecular Determinants Of The Zinc Transporter, Hzip4, Robert Dempski, Sagar Antala, Tuong-Vi Nguyen

Robert E. Dempski

Zinc is an essential micronutrient which is required for the function of hundreds of cellular enzymes. In addition, zinc is the second most abundant transition metal found in biological systems (iron is most abundant). However, the concentration of free zinc is nano to picomolar since most zinc is bound to proteins. This makes investigating the mechanism of zinc transport across the plasma membrane a challenge. Our interest has been to elucidate the mechanism of zinc transport mediated by one member of the ZIP family of proteins, hZIP4.

Sharks Of The Devonian, Andrew Blitman

Andrew Blitman

No abstract provided.

The Extracellular Chaperone Clusterin Sequesters Oligomeric Forms Of The Amyloid-Beta 1-40 Peptide, Priyanka Narayan, Angel Orte, Richard Clarke, Benedetta Bolognesi, Sharon Hook, Kristina Ganzinger, Sarah Meehan, Mark Wilson, Christopher Dobson, David Klenerman

Mark R Wilson

In recent genome-wide association studies, the extracellular chaperone protein, clusterin, has been identified as a newly-discovered risk factor in Alzheimer's disease. We have examined the interactions between human clusterin and the Alzheimer's disease-associated amyloid-β 1-40 peptide (Aβ 1-40), which is prone to aggregate into an ensemble of oligomeric intermediates implicated in both the proliferation of amyloid fibrils and in neuronal toxicity. Using highly sensitive single-molecule fluorescence methods, we have found that Aβ 1-40 forms a heterogeneous distribution of small oligomers (from dimers to 50-mers), all of which interact with clusterin to form long-lived, stable complexes. Consequently, clusterin is able to …

Polyelectrolyte Complex Materials Consisting Of Antibacterial And Cell-Supporting Layers, Khairul Mat Amin, Kerry Gilmore, Jake Matic, Stephen Poon, Mark Walker, Mark Wilson, Marc In Het Panhuis

Mark R Wilson

The characterization of a polyelectrolyte complex material comprised of two biopolymers, a chitosan upper layer and a gellan gum under layer, is reported. It is shown that the upper layer of chitosan with incorporated levofloxacin displays an antibacterial activity, while the under layer of a gellan gum/TiO2 composite supports the growth of fibroblastic cells.

Sex-Specific Sod Levels And Dna Damage In Painted Dragon Lizards (Ctenophorus Pictus), Mats Olsson, Mo Healey, Cecile Perrin, Mark Wilson, Michael Tobler

Mark R Wilson

When groups of individuals differ in activities that may influence the production of reactive molecules, such as superoxide, we expect selection to result in congruent upregulation of antioxidant production in the group(s) most at risk of suffering concomitant erosion of essential tissue and biomolecules, such as DNA. We investigate this in a (near) annual lizard species, the Australian painted dragon (Ctenophorus pictus), in which males and females have fundamentally different lifestyles, with males being overtly conspicuous and aggressive, whereas females are placid and camouflaged. When kept in identical conditions to females in captivity, males had higher levels of superoxide dismutase …

Predictors Of Telomere Content In Dragon Lizards, Cissy Ballen, Mo Healey, Mark Wilson, Michael Tobler, Mats Olsson

Mark R Wilson

Telomeres shorten as a consequence of DNA replication, in particular in cells with low production of telomerase and perhaps in response to physiological stress from exposure to reactive oxygen species, such as superoxide. This process of telomere attrition is countered by innate antioxidation, such as via the production of superoxide dismutase. We studied the inheritance of telomere length in the Australian painted dragon lizard (Ctenophorus pictus) and the extent to which telomere length covaries with masscorrected maternal reproductive investment, which reflects the level of circulating yolk precursor and antioxidant, vitellogenin. Our predictors of offspring telomere length explained 72 % of …

A Significant Component Of Ageing (Dna Damage) Is Reflected In Fading Breeding Colors: An Experimental Test Using Innate Antioxidant Mimetics In Painted Dragon Lizards, Mats Olsson, Michael Tobler, Mo Healey, Cecile Perrin, Mark Wilson

Mark R Wilson

A decade ahead of their time, von Schantz et al. united sexual selection and free radical biology by identifying causal links between deep-rooted physiological processes that dictate resistance to toxic waste from oxidative metabolism (reactive oxygen species, ROS), and phenotypic traits, such as ornaments.Ten years later, these ideas have still only been tested with indirect estimates of free radical levels (oxidative stress) subsequent to the action of innate and dietary antioxidants. Here, we measure net superoxide (a selection pressure for antioxidant production) and experimentally manipulate superoxide antioxidation using a synthetic mimetic of superoxide dismutase (SOD), Eukarion 134 (EUK). We then …

Amyloid-Β Oligomers Are Sequestered By Both Intracellular And Extracellular Chaperones, P Narayan, Sarah Meehan, John Carver, Mark Wilson, C M Dobson, D Klenerman

Mark R Wilson

The aberrant aggregation of the amyloid-β peptide into β-sheet rich, fibrillar structures proceeds via a heterogeneous ensemble of oligomeric intermediates that have been associated with neurotoxicity in Alzheimer’s disease (AD). Of particular interest in this context are the mechanisms by which molecular chaperones, part of the primary biological defenses against protein misfolding, influence Aβ aggregation. We have used single-molecule fluorescence techniques to compare the interactions between distinct aggregation states (monomers, oligomers, and amyloid fibrils) of the AD-associated amyloid-β(1–40) peptide, and two molecular chaperones, both of which are upregulated in the brains of patients with AD and have been found colocalized …

Net Superoxide Levels: Steeper Increase With Activity In Cooler Female And Hotter Male Lizards, Cissy Ballen, Mo Healey, Mark Wilson, Michael Tobler, Erik Wapstra, Mats Olsson

Mark R Wilson

"Ectotherms increase their body temperature in response to ambient heat, thereby elevating their metabolic rate. An often inferred consequence of this is an overall upregulation of gene expression and energetic expenditure, and a concomitant increased production of reactive oxygen species (e. g. superoxide) and, perhaps, a shortened lifespan. However, recent work shows that this may be a superficial interpretation. For example, sometimes a reduced temperature may in fact trigger up-regulation of gene expression. We studied temperature and associated activity effects in male and female Australian painted dragon lizards (Ctenophorus pictus) by allowing the lizards to bask for 4 h versus …