Synthesis of β-Alanine From Isoleucine and Propionate Catabolism via Aminotransferases.

In plants, the nonproteinogenic amino acid β-alanine plays a role in response to hypoxia, flooding, drought, heat, and heavy metal stress conditions. It is also a key intermediate in the synthesis of essential molecules including vitamin B5 and coenzyme A (CoA) through the condensation reaction with pantoate. While the syntheses of pantoate, vitamin B5, and CoA appear to be conserved across plants and bacteria, the synthesis of β-alanine is not.

A Swing-Assist Controller for Enhancing Knee Flexion in a Semi-Powered Transfemoral Prosthesis.

This work proposes a new swing controller for semi-powered low impedance transfemoral prostheses that resolves the issue of potentially competing inputs between artificial assistive power and user-sourced power. Rather than add power as an exogeneous input, the control approach uses power to modify the homogeneous portion of the shank dynamics, and therefore need not construct or curate an input that is coordinated with user input. The implemented controller requires a single control parameter at a given walking speed, where the value of that parameter is a function of walking speed, as determined by an adaptive algorithm, such that peak knee angles are commensurate with walking-speed-dependent behaviors of individuals without any negative gait pathologies.