Publications by authors named "W A Johnston"

The occurrence of environmental hypoxia in freshwater and marine aquatic systems has increased over the last century and is predicted to further increase with climate change. As members of the largest extant vertebrate group, freshwater fishes, and to a much lesser extent marine fishes, are vulnerable to increased occurrence of hypoxia. This is important as fishes render important ecosystem services and have important cultural and economic roles.

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In this study, an analytical model was developed to predict the sound absorption performance of fibrous absorbers fabricated using an extrusion-based three-dimensional (3D) printing method. The proposed model employs geometric design parameters, including the average fiber diameter and the horizontal and vertical fiber separations, to calculate the porosity, static airflow resistivity, tortuosity, and viscous and thermal characteristic lengths. These transport parameters are then used within the Johnson-Champoux-Allard semiempirical formulation to predict the normal incidence sound absorption coefficient.

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Background: Lung contusion (LC) complicated by pneumonia is associated with a higher risk of acute lung injury (ALI) mediated by activation of immune cells and injury to the lung epithelium. Small extracellular vesicles (sEVs) are essential mediators of cellular crosstalk; however, their role in the development of postinjury ALI remains unclear. We hypothesized that LC complicated by pneumonia increases the pro-inflammatory effect of alveolar sEVs on macrophages and the cytotoxicity of alveolar sEVs to pulmonary epithelial cells, worsening the severity of ALI.

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This protocol outlines the production and optimization of a eukaryotic Cell-Free Protein Expression System (CFPS) derived from the unicellular flagellate Leishmania tarentolae, referred to as Leishmania Translational Extract or LTE. Although this organism originally evolved as a parasite of geckos, it can be cultivated easily and inexpensively in flasks or bioreactors. Unlike Leishmania major, it is non-pathogenic to humans and does not require special laboratory precautions.

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Introduction: Clostridium sordellii (C sordellii) is a gram positive, anaerobic bacterium that causes severe, often fatal infections. Classically, C sordellii infection is described as a high mortality process for women of childbearing age. We examined C sordellii infections in our hospital to determine if there have been any changes in prevalence, treatment, or outcome.

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