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The existence of finite amplitude shape distortion caused by parametrically excited surface instabilities for a gas bubble in water driven by a temporally periodic, spatially uniform pressure field in an axisymmetric geometry is investigated. Employing a nonlinear coupled system of equations which includes shape mode interactions to third order, the resultant spherical oscillations, translation, and shape distortion of the bubble are modelled, placing no restriction on the size of the spherical oscillations. The model accounts for viscous and thermal damping with compressibility effects. The existence of synchronous and higher order parametrically induced sustained, finite amplitude, periodic shape deformation is demonstrated. The excitement of an odd shape mode via the synchronous mechanism is shown to give rise to linear bubble self-propulsion. For larger driving amplitudes, it is shown that more than one shape mode can be parametrically excited at the same driving frequency but by different resonance mechanisms, leading to more involved shape deformation and the increased possibility of bubble self-propulsion., (© 2024 Acoustical Society of America.)

Cleavage of bacteriophage DNA by the Type III restriction-modification enzymes requires long-range interaction between DNA sites. This is facilitated by one-dimensional diffusion ('DNA sliding') initiated by ATP hydrolysis catalyzed by a superfamily 2 helicase-like ATPase. Here we combined ultrafast twist measurements based on plasmonic DNA origami nano-rotors with stopped-flow fluorescence and gel-based assays to examine the role(s) of ATP hydrolysis. Our data show that the helicase-like domain has multiple roles. First, this domain stabilizes initial DNA interactions alongside the methyltransferase subunits. Second, it causes environmental changes in the flipped adenine base following hydrolysis of the first ATP. Finally, it remodels nucleoprotein interactions via constrained translocation of a ∼ 5 to 22-bp double stranded DNA loop. Initiation of DNA sliding requires 8-15 bp of DNA downstream of the motor, corresponding to the site of nuclease domain binding. Our data unify previous contradictory communication models for Type III enzymes., (© 2024. The Author(s).)

The self-propulsion (translational instability) of a gas bubble in a liquid undergoing parametrically induced axisymmetric shape distortion due to being forced by a temporally sinusoidal, spatially constant acoustic field is investigated. Employing a model which accounts for the nonlinear coupling between the spherical oscillations, the axial translation and shape deformation of the bubble, the parametric excitement of two neighboring shape modes by the fundamental resonance, at the same driving frequency is studied. It is shown that provided pertinent driving pressure threshold values are exceeded, the respective shape modes are excited on different timescales. The growth of the shape mode on the faster timescale saturates giving rise to sustained constant amplitude oscillations, while the growth of the shape mode on the slower timescale is both modulated and unbounded. During the growth of the second shape mode, growing, oscillatory bubble translation is also observed.

Bacteria have evolved a variety of defence mechanisms to protect against mobile genetic elements, including restriction-modification systems and CRISPR-Cas. In recent years, dozens of previously unknown defence systems (DSs) have been discovered. Notably, diverse DSs often coexist within the same genome, and some co-occur at frequencies significantly higher than would be expected by chance, implying potential synergistic interactions. Recent studies have provided evidence of defence mechanisms that enhance or complement one another. Here, we review the interactions between DSs at the mechanistic, regulatory, ecological and evolutionary levels., Competing Interests: Declaration of Competing Interest AM and EW are inventors on patent GB2303034.9., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: While most studies on burn outcomes have focused on adults, it is unclear if the same socioeconomic and environmental inequalities affect paediatric patients. This study aims to investigate the impact of race and ethnicity on outcomes in paediatric burn patients., Methods: The Kids' Inpatient Database is released by Agency for Healthcare Research and Quality, and is the largest publicly available database for the United States inpatient paediatric population. All paediatric burned patients in 2016 and 2019 were identified. Race and/or ethnicity was the primary exposure variable, and the primary outcome was a composite of several in-hospital morbidities. Secondary outcomes included death, non-routine disposition, and length of stay. Fine-Gray competing risks regression and multivariable logistic regression were used to analyze length of stay and all other outcomes, respectively. Analysis also isolated subgroups related to socioeconomic status and case severity., Results: We included12,582 pediatric burn patients in this study. No difference was found in composite morbidity between White patients and those of other race or ethnicity groups. Hispanic ethnicity was associated with longer lengths of stay and increased odds of routine (i.e. home) discharge. Black patients had increased length of stay compared to White patients only in severe burn cases., Conclusions: Our study implies that race- or ethnicity-associated mechanisms driving outcome disparities in adults does not necessarily apply in paediatric burn patients., Competing Interests: Declaration of Competing Interest The University of California has received funding and product for other research projects from Epimed International (Farmers Branch, TX); Infutronics (Natick, MA); Precision Genetics (Greenville County, SC); and SPR Therapeutics (Cleveland, OH) for the following author: Dr. Gabriel. The University of California San Diego is a consultant for Avanos (Alpharetta, GA), in which Dr. Gabriel represents., (Copyright © 2023 Elsevier Ltd and International Society of Burns Injuries. All rights reserved.)