Publications by authors named "PD Johnson"

There is a large burden of stroke in the United States, and extensive systems of care have been established to address it. The resources devoted to stroke centers are analogous to those of trauma centers, both sharing many strict requirements for certification, clinical preparedness, quality improvement, data management, and reporting. However, trauma programs partly defray these costs through a trauma activation billing code, a billable fee that is charged for activation of the trauma team under strict criteria.

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We describe two locally acquired cases of Mycobacterium ulcerans infection (Buruli ulcer) in the town of Batemans Bay on the east coast of New South Wales (NSW), Australia, 150 km north of Eden, the only other place in NSW where Buruli ulcer has likely been locally acquired. Genomic analysis showed that the bacterial isolates from the cases were identical but belonged to a phylogenetically distinct M. ulcerans clade that was most closely related to the isolate from the earlier case in Eden to the south.

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Background: Antimicrobial stewardship (AMS) guidelines now recommend antifungal stewardship (AFS) interventions to improve the management of invasive fungal diseases (IFDs). AFS programmes have not been reported in Australia.

Aims: To determine the monitoring of antifungal use, AFS strategies and targets, and barriers to AFS implementation in Australian hospitals.

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The gut microbiome is influenced by host species and the environment, but how the environment influences the microbiome of animals introduced into a new ecosystem has rarely been investigated. Freshwater mussels are aquatic fauna, with some threatened or endangered species propagated in hatcheries and introduced into natural systems as part of conservation efforts. The effects of the environment on the freshwater mussel gut microbiome were assessed for two hatchery-propagated species (, ) introduced into rivers within their natural range.

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Article Synopsis
  • There's a significant lack of critical knowledge that is slowing down efforts to address Buruli ulcer (BU), a neglected tropical disease.
  • A new human infection model for BU is being proposed to investigate how the disease interacts with the host and to test prevention and treatment options.
  • The authors have shared a preliminary protocol for this study, seeking input from the scientific community and stakeholders before refining it for official review by an institutional board.
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  • Alphavirus infections are spread by mosquitoes, whereas the transmission method of Mycobacterium ulcerans, responsible for Buruli ulcer, is still debated.
  • Research using notification data from Victoria, Australia, from 2017 to 2022 shows a close correlation between the seasons of alphavirus and Buruli ulcer cases.
  • This alignment supports the theory that Mycobacterium ulcerans could also be transmitted by mosquitoes.
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Unionoid freshwater mussels (Bivalvia: Unionidae) are free-living apart from a brief, obligately parasitic, larval stage that infects fish hosts, and gravid female mussels have evolved a spectrum of strategies to infect fish hosts with their larvae. In many North American species, this involves displaying a mantle lure: a pigmented fleshy extension that acts as an aggressive mimic of a host fish prey, thereby eliciting a feeding response that results in host infection. The mantle lure of is of particular interest because it is apparently polymorphic, with two distinct primary lure phenotypes.

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Critical scientific questions remain regarding infection with Mycobacterium ulcerans, the organism responsible for the neglected tropical disease, Buruli ulcer (BU). A controlled human infection model has the potential to accelerate our knowledge of the immunological correlates of disease, to test prophylactic interventions and novel therapeutics. Here we present microbiological evidence supporting M.

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The primordial ingredient of cuprate superconductivity is the CuO unit cell. Theories usually concentrate on the intra-atom Coulombic interactions dominating the 3d and 3d configurations of each copper ion. However, if Coulombic interactions also occur between electrons of the 2p orbitals of each planar oxygen atom, spontaneous orbital ordering may split their energy levels.

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Buruli ulcer, a chronic subcutaneous infection caused by Mycobacterium ulcerans, is increasing in prevalence in southeastern Australia. Possums are a local wildlife reservoir for M. ulcerans and, although mosquitoes have been implicated in transmission, it remains unclear how humans acquire infection.

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Article Synopsis
  • Vancomycin-resistant enterococci (VRE) infections, particularly from specific genotypes, are becoming more common, highlighting the need for genomic studies to understand their evolution.
  • Researchers conducted a genomic analysis of a vancomycin-resistant enterococcus strain that emerged from a previously susceptible strain, identifying three major genomic variations including an integrative conjugative element and two structural changes in the genome.
  • The study suggests that the mobile genetic elements responsible for these variations are widespread and can be transferred across different bacterial genera, which is important for addressing the growing issue of antimicrobial resistance despite the low incidence of this specific VRE strain.
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We herein describe Proterometra wigglewomble n. sp. (Digenea: Azygiidae: Azygiinae) from the Cahaba River, Alabama, USA, which asexually reproduces in the compact elimia, Elimia showalteri (Lea, 1860) (Cerithioidea: Pleuroceridae) and matures in the oesophagus of the blackbanded darter, Percina nigrofasciata (Agassiz, 1854) (Perciformes: Percidae).

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Freshwater mussels are important indicators of the overall health of their environment but have suffered declines that have been attributed to factors such as habitat degradation, a loss of fish hosts, climate change, and excessive nutrient inputs. The loss of mussel biodiversity can negatively impact freshwater ecosystems such that understanding the mussel's gut microbiome has been identified as a priority topic for developing conservation strategies. In this study, we determine whether ethanol-stored specimens of freshwater mussels can yield representative information about their gut microbiomes such that changes in the microbiome through time could potentially be determined from museum mussel collections.

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Introduction: Mycobacterium ulcerans (MU) causes Buruli ulcer (Buruli), a geographically restricted infection that can result in skin loss, contracture and permanent scarring. Lesion-location maps compiled from more than 640 cases in south eastern Australia suggest biting insects are likely involved in transmission, but it is unclear whether MU is brought by insects to humans or if MU is already on the skin and inoculation is an opportunistic event that need not be insect dependent.

Methods: We validated a PCR swab detection assay and defined its dynamic range using laboratory cultured M.

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Workplace aggression consists of harmful actions between co-workers, supervisors, and subordinates. In this series of studies, we draw from attachment theory and competitive personality to develop and test a mediated model of workplace aggression that incorporates relational working models (i.e.

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Critical knowledge gaps regarding infection with Mycobacterium ulcerans, the cause of Buruli ulcer (BU), have impeded development of new therapeutic approaches and vaccines for prevention of this neglected tropical disease. Here, we review the current understanding of host-pathogen interactions and correlates of immune protection to explore the case for establishing a controlled human infection model of M. ulcerans infection.

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Background: Buruli ulcer (BU) is a neglected tropical disease caused by infection of subcutaneous tissue with . BU is commonly reported across rural regions of Central and West Africa but has been increasing dramatically in temperate southeast Australia around the major metropolitan city of Melbourne, with most disease transmission occurring in the summer months. Previous research has shown that Australian native possums are reservoirs of and that they shed the bacteria in their fecal material (excreta).

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Article Synopsis
  • The study investigates COVID-19 severity (hospitalization and death rates) among residents of residential aged care facilities (RACFs) in Victoria, Australia, during Delta and Omicron epidemic periods.
  • Results show that the hospitalization risk (HR) and case fatality risk (CFR) were significantly lower during the Omicron period compared to Delta, with vaccination status playing a crucial role in reducing these risks.
  • The findings emphasize the importance of staying up-to-date with vaccinations to mitigate COVID-19 severity among elderly residents, as males and those with longer intervals since last vaccination faced higher risks.
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Recently, evidence has emerged in the topological superconductor Fe-chalcogenide FeTe_{1-x}Se_{x} for time-reversal symmetry breaking (TRSB), the nature of which has strong implications on the Majorana zero modes (MZM) discovered in this system. It remains unclear, however, whether the TRSB resides in the topological surface state (TSS) or in the bulk, and whether it is due to an unconventional TRSB superconducting order parameter or an intertwined order. Here, by performing in superconducting FeTe_{1-x}Se_{x} crystals both surface-magneto-optic-Kerr effect measurements using a Sagnac interferometer and bulk magnetic susceptibility measurements, we pinpoint the TRSB to the TSS, where we also detect a Dirac gap.

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Therapeutic interventions are being developed for Huntington's disease (HD), a hallmark of which is mutant huntingtin protein (mHTT) aggregates. Following the advancement to human testing of two [C]-PET ligands for aggregated mHTT, attributes for further optimization were identified. We replaced the pyridazinone ring of CHDI-180 with a pyrimidine ring and minimized off-target binding using brain homogenate derived from Alzheimer's disease patients.

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Measuring quantum observables by grouping terms that can be rotated to sums of only products of Pauli operators (Ising form) is proven to be efficient in near term quantum computing algorithms. This approach requires extra unitary transformations to rotate the state of interest so that the measurement of a fragment's Ising form would be equivalent to the measurement of the fragment for the unrotated state. These extra rotations allow one to perform a fewer number of measurements by grouping more terms into the measurable fragments with a lower overall estimator variance.

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Electron-pair density wave (PDW) states are now an intense focus of research in the field of cuprate correlated superconductivity. PDWs exhibit periodically modulating superconductive electron pairing that can be visualized directly using scanned Josephson tunneling microscopy (SJTM). Although from theory, intertwining the -wave superconducting (DSC) and PDW order parameters allows a plethora of global electron-pair orders to appear, which one actually occurs in the various cuprates is unknown.

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Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion in the huntingtin () gene that encodes the pathologic mutant HTT (mHTT) protein with an expanded polyglutamine (polyQ) tract. Whereas several therapeutic programs targeting mHTT expression have advanced to clinical evaluation, methods to visualize mHTT protein species in the living brain are lacking. Here, we demonstrate the development and characterization of a positron emission tomography (PET) imaging radioligand with high affinity and selectivity for mHTT aggregates.

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