Control of Chemical Waves by Fluid Stretching and Compression.

Oscillatory kinetics coupled to diffusion can produce traveling waves as observed in physical, chemical, and biological systems. We show experimentally that the properties of such waves can be controlled by fluid stretching and compression in a hyperbolic flow. Localized packet waves consisting in a train of parallel waves can develop due to a balance between diffusive broadening and advective compression along the unstable manifold.

Older adults' perceptions of ageism, discrimination, and racism.

Older adults often experience different forms of discrimination, whether it be on the basis of their age, gender, race, or ethnicity (Rochon et al. 2021). Many older adults have stated they have experienced the health care system differently because of their race or ethnicity .

Microscale Chaotic Mixing as a Driver for Chemical Reactions in Porous Media.

Mixing-induced reactions play a key role in a large range of biogeochemical and contaminant transport processes in the subsurface. Fluid flow through porous media was recently shown to exhibit chaotic mixing dynamics at the pore scale, enhancing microscale concentration gradients and controlling mixing rates. While this phenomenon is likely ubiquitous in environmental systems, it is not known how it affects chemical reactions.

Waking up Sleeping Beauty: DNA damage activates dormant stem cell division by enhancing brassinosteroid signaling.

This article comments on: Takahashi N, Suita K, Koike T, Ogita N, Zhang Y, Umeda M. 2024. DNA double-strand breaks enhance brassinosteroid signaling to activate quiescent center cell division in Arabidopsis.