Publications by authors named "Sarah E Johnston"

Article Synopsis
  • Environmental factors like water quality and sediment affect how metals, such as cadmium, behave in aquatic systems and their interaction with microplastics.
  • A study using lab experiments and machine learning found that alkalinity, humification index of dissolved organic matter, and pH were key water quality factors influencing the amount of cadmium adsorbed to microplastics.
  • The research showed that even though cadmium levels varied on microplastics, there was no significant difference in cadmium uptake by fathead minnows, suggesting water quality changes might complicate the risks posed by microplastics and metals.
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Through emission processes, palladium (Pd) particulates from industrial sources are introduced into a range of ecosystems including freshwater environments. Despite this, research on Pd-induced bioaccumulation, uptake, and toxicity is limited for freshwater fishes. Unlike other metals, there are currently no regulations or protective guidelines to limit Pd release into aquatic systems, indicating a global absence of measures addressing its environmental impact.

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Unlabelled: Wetlands have been used to treat anthropogenic effluents for decades due to their intense biogeochemical processes that transform and uptake nutrients, organic matter, and toxins. Despite these known functions, we lack generalizable knowledge of effluent-derived dissolved organic matter (DOM) cycling in wetlands. Here, we quantify the cycling of DOM in one of Canada's more economically important wetland complexes (Frank Lake, Alberta), restored to hydrologic permanence in the 1980s using urban and agro-industrial effluents.

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In this paper, we consider randomized controlled clinical trials comparing two treatments in efficacy assessment using a time to event outcome. We assume a relatively small number of candidate biomarkers available in the beginning of the trial, which may help define an efficacy subgroup which shows differential treatment effect. The efficacy subgroup is to be defined by one or two biomarkers and cut-offs that are unknown to the investigator and must be learned from the data.

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Introduction: The purpose of this study was to compare the metabolism of Streptococcus mutans biofilms after 1-7 days of growth on different orthodontic adhesives.

Methods: Specimens of 6 commercial orthodontic adhesives were fabricated in custom-made molds and polymerized using a light-emitting diode light-curing unit. Bioluminescent S mutans (UA159:JM10) biofilms were grown on ultraviolet-sterilized specimens for 1, 3, 5, and 7 days (n = 18 biofilms/d/product) in anaerobic conditions at 37°C.

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Background: Treatment of metastatic melanoma possesses challenges due to drug resistance and metastases. Recent advances in targeted therapy and immunotherapy have shown clinical benefits in melanoma patients with increased survival. However, a subset of patients who initially respond to targeted therapy relapse and succumb to the disease.

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Objective: In the healthy spine, the spinal cord moves unimpeded with spinal fluid pulsation in the rostral and caudal directions. When a portion of the spinal cord becomes attached to lesions within the spinal column, excess strain can cause signs and symptoms such as pain, motor deficits, sensory deficits, bladder dysfunction, and bowel dysfunction. This condition is termed tethered cord syndrome.

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Objective: Inflammatory and immunologic cytokines and vagal activity have important roles in health and mental health, and may influence each other. The authors assessed relationships of representative biomarkers linked to disaster exposure-heart rate variability (HRV) with Interleukin-2 (IL-2, cell-medicated immunity) and Interleukin-6 (IL-6, pro-inflammatory and pro-immunologic), stratified by psychiatric diagnosis.

Design: Participants were assessed for psychiatric diagnosis, IL-2, IL-6, HRV, and HR reactivity to trauma reminders.

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Cholinergic hypofunction is associated with decreased attention and cognitive deficits in the central nervous system in addition to compromised motor function. Consequently, stimulation of cholinergic neurotransmission is a rational therapeutic approach for the potential treatment of a variety of neurological conditions. High affinity choline uptake (HACU) into acetylcholine (ACh)-synthesizing neurons is critically mediated by the sodium- and pH-dependent high-affinity choline transporter (CHT, encoded by the gene).

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