Publications by authors named "Tracey John"

Many estuaries experience eutrophication, deoxygenation and warming, with potential impacts on greenhouse gas emissions. However, the response of NO production to these changes is poorly constrained. Here we applied nitrogen isotope tracer incubations to measure NO production under experimentally manipulated changes in oxygen and temperature in the Chesapeake Bay-the largest estuary in the United States.

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Disparities in preventative health care likely contribute to comorbidities associated with neurodevelopmental disability. These comorbidities are risk factors for poor outcomes of COVID-19, making COVID-19 vaccination a priority for this population. In mid-2021, the Australian Technical Advisory Group (ATAGI) recommended the COVID-19 vaccination rollout include children and young people at risk of severe COVID-19 associated disease.

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Background: Magnetic resonance imaging scanner faults can be missed during routine quality assurance (QA) if they are subtle, intermittent, or the test being performed is insensitive to the type of fault. Coil element malfunction is a common fault within MRI scanners, which may go undetected for quite some time. Consequently, this may lead to poor image quality and the potential for misdiagnoses.

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The BvgAS two-component system regulates virulence gene expression in . Although precise three-dimensional structural information is not available for the response regulator BvgA, its sequence conservation with NarL and previous studies have indicated that it is composed of 3 domains: an -terminal domain (NTD) containing the phosphorylation site, a linker, and a DNA-binding C-terminal domain (CTD). Previous work has determined how BvgA dimers interact with the promoter (P ) of , the gene encoding the virulence adhesin filamentous hemagglutinin.

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Calcite dissolution is initiated by the formation of a nanoscale etch pit followed by step edge propagation and hence strongly influenced by the interactions between surface diffusing ions and step edges. However, such atomic-scale dynamics are mostly inaccessible with current imaging tools. Here, we overcome this limitation by using our recent development of high-speed frequency modulation atomic force microscopy.

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Mineral-water interfaces play an important role in many natural as well as technological fields. Fundamental properties of these interfaces are governed by the presence of the interfacial water and its specific structure at the surface. Calcite is particularly interesting as a dominant rock-forming mineral in the earth's crust.

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The ocean is a net source of NO, a potent greenhouse gas and ozone-depleting agent. However, the removal of NO via microbial NO consumption is poorly constrained and rate measurements have been restricted to anoxic waters. Here we expand NO consumption measurements from anoxic zones to the sharp oxygen gradient above them, and experimentally determine kinetic parameters in both oxic and anoxic seawater for the first time.

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Article Synopsis
  • Calcite and magnesite are key minerals in the earth's crust that interact with organic molecules, influencing the formation of biominerals.
  • Advanced 3D atomic force microscopy (AFM) allows visualization of solid-liquid interfaces at a molecular level, focusing on how ethanol behaves on the surfaces of these carbonates.
  • The study shows that ethanol assembles in distinct layers on calcite and magnesite, with the first layer being well-ordered due to specific binding interactions, while subsequent layers are less ordered, reflecting the different chemical contexts.
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In this study, we have investigated the influence of the tip on the three-dimensional scanning force microscopy (3D-SFM) images of calcite-water interfaces by experiments and simulations. We calculated 3D force images by simulations with the solvent tip approximation (STA), Ca, CO3 and OH tip models. For all the 3D images, the z profiles at the surface Ca and CO3 sites alternately show oscillatory peaks corresponding to the hydration layers.

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Many prokaryotes encode protein-based encapsulin nanocompartments, including anaerobic ammonium oxidizing (anammox) bacteria. This study expands the list of known anammox encapsulin systems from freshwater species to include the marine genus Scalindua. Two novel systems, identified in "Candidatus Scalindua rubra" and "Candidatus Scalindua sp.

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Substituting heteroatoms into nanostructured graphene elements, such as graphene nanoribbons, offers the possibility for atomic engineering of electronic properties. To characterize these substitutions, functionalized atomic force microscopy (AFM)-a tool to directly resolve chemical structures-is one of the most promising tools, yet the chemical analysis of heteroatoms has been rarely performed. We synthesized multiple heteroatom-substituted graphene nanoribbons and showed that AFM can directly resolve elemental differences and can be correlated to the van der Waals radii, as well as the modulated local electron density caused by the substitution.

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According to Hückel theory, an anti-aromatic molecule possessing (4n)π-electrons becomes unstable. Although the stabilization has been demonstrated by radialene-type structures-fusing aromatic rings to anti-aromatic rings-in solution, such molecules have never been studied at a single molecular level. Here, we synthesize a cyclobutadiene derivative, dibenzo[b,h]biphenylene, by an on-surface intramolecular reaction.

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The microscopic understanding of the crystal growth and dissolution processes have been greatly advanced by the direct imaging of nanoscale step flows by atomic force microscopy (AFM), optical interferometry, and X-ray microscopy. However, one of the most fundamental events that govern their kinetics, namely, atomistic events at the step edges, have not been well understood. In this study, we have developed high-speed frequency modulation AFM (FM-AFM) and enabled true atomic-resolution imaging in liquid at ∼1 s/frame, which is ∼50 times faster than the conventional FM-AFM.

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The hydrogen atom-the smallest and most abundant atom-is of utmost importance in physics and chemistry. Although many analysis methods have been applied to its study, direct observation of hydrogen atoms in a single molecule remains largely unexplored. We use atomic force microscopy (AFM) to resolve the outermost hydrogen atoms of propellane molecules via very weak C═O⋅⋅⋅H-C hydrogen bonding just before the onset of Pauli repulsion.

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Solid-liquid interfaces are decisive for a wide range of natural and technological processes, including fields as diverse as geochemistry and environmental science as well as catalysis and corrosion protection. Dynamic atomic force microscopy nowadays provides unparalleled structural insights into solid-liquid interfaces, including the solvation structure above the surface. In contrast, chemical identification of individual interfacial atoms still remains a considerable challenge.

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Frequency modulation atomic force microscopy (FM-AFM) experiments were performed on the calcite (10[Formula: see text]4) surface in pure water, and a detailed analysis was made of the 2D images at a variety of frequency setpoints. We observed eight different contrast patterns that reproducibly appeared in different experiments and with different measurement parameters. We then performed systematic free energy calculations of the same system using atomistic molecular dynamics to obtain an effective force field for the tip-surface interaction.

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The abundance of Aulacoseira granulata (Ehrenburg) Simonsen and Gloeocystis planctonica (West & G.S.West) Lemmermann was assessed during the summers of 2005 and 2010 in the eutrophic Fox River, Wisconsin, USA.

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We investigated carriage of avian influenza viruses by wild birds in Australia, 2005-2008, to assess the risks to poultry industries and human health. We collected 21,858 (7,357 cloacal, 14,501 fecal) samples and detected 300 viruses, representing a detection rate of ≈1.4%.

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A growing body of work in the literature describes and explains narrative pedagogy within nursing and midwifery programs. This paper continues the conversation by explaining, with examples, how narrative pedagogy has been interpreted and applied within a new nursing faculty in Australia. The aims of our nursing and midwifery programs are to provide students with a clear professional identity and to prepare them for contemporary Australian nursing practice.

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Plagioporus kolipinskii n. sp. (Trematoda: Opecoelidae) is described from the intestine of the threespine stickleback, Gasterosteus aculeatus L.

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Drawing on the power of ritual, storytelling and lessons from history and our professional elders, nursing academics at the University of the Sunshine Coast organised a three-hour event on International Nurses Day. The aims were to model to students the importance of producing their own nursing stories and to celebrate and stimulate conversation about the diverse, rich, local and national history of nursing. The event included: an oration from an influential guest speaker; video footage of nurses telling their stories; an historical display of nursing artefacts; opportunities for participants to record their stories; and opportunities for students, staff and the local nursing fraternity to engage with each other.

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Bloodless surgery programs are being instituted because of increasing public concerns about blood transfusions and the need to accommodate some patients' religious beliefs. Patients' desires to forego transfusion must be identified during the preoperative screening process and subsequently reflected on the surgical consent. Patients are managed preoperatively with erythropoietin and dietary supplements.

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Some surgical procedures can be performed more safely outside the OR. One procedure commonly performed within the neonatal intensive care unit (NICU) is patent ductus arteriosus (PDA) ligation. Staff members at one tertiary care facility assessed current management and delivery of bedside PDA ligation surgery and identified several problem areas, including communication issues regarding patient and unit readiness, design of instrument sets, and organization and transportation of surgical supplies.

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