Publications by authors named "Geoffrey Vrla"

Surface attachment, an early step in the colonization of multiple host environments, activates the virulence of the human pathogen P. aeruginosa. However, the downstream toxins that mediate surface-dependent P.

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Caenorhabditis elegans must distinguish pathogens from nutritious food sources among the many bacteria to which it is exposed in its environment. Here we show that a single exposure to purified small RNAs isolated from pathogenic Pseudomonas aeruginosa (PA14) is sufficient to induce pathogen avoidance in the treated worms and in four subsequent generations of progeny. The RNA interference (RNAi) and PIWI-interacting RNA (piRNA) pathways, the germline and the ASI neuron are all required for avoidance behaviour induced by bacterial small RNAs, and for the transgenerational inheritance of this behaviour.

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Article Synopsis
  • A study explored how dimetallic sequences built on a backbone with two tyrosine moieties can self-assemble into different structures depending on the metal used.
  • Sequences containing rhenium (Re) produced amyloid-like nanofibers, indicating that the specific arrangement of metals affects the resulting morphology.
  • The research also found that a more complex sequence with three metals (rhodium, platinum, and rhenium) could also fibrillate, and cyclic voltammetry showed that the redox activity of the metals remained intact in their nanofibrous forms.
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In the pathogen Pseudomonas aeruginosa, LasR is a quorum sensing (QS) master regulator that senses the concentration of secreted autoinducers as a proxy for bacterial cell density. Counterintuitively, previous studies showed that saturating amounts of the LasR ligand, 3OC12-HSL, fail to induce the full LasR regulon in low-density liquid cultures. Here we demonstrate that surface association, which is necessary for many of the same group behaviors as QS, promotes stronger QS responses.

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Extensive research has linked the amyloid-beta (Aβ) peptide to neurological dysfunction in Alzheimer's disease (AD). Insoluble Aβ plaques in the AD patient brain contain high concentrations of advanced glycation end-products (AGEs) as well as transition metal ions. This research elucidated the roles of Aβ, sugars, and Cu in the oxidative stress mechanism of AD at the molecular level.

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The role of vascular smooth muscle architecture in the function of healthy and dysfunctional vessels is poorly understood. We aimed at determining the relationship between vascular smooth muscle architecture and contractile output using engineered vascular tissues. We utilized microcontact printing and a microfluidic cell seeding technique to provide three different initial seeding conditions, with the aim of influencing the cellular architecture within the tissue.

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