Closed-loop swing-up and stabilization of inverted pendulum by finite-horizon LQR applied in 2-DOF concept

The general framework of this paper is the control design of complex nonlinear systems. The proposed approach is demonstrated with the use of a case study regarding a typical mechatronic system - control design of inverted pendulum on the cart. The methodology used for the solution of this problem is based on two- degree of freedom control structure (2-DOF) with feed-forward and feedback terms. Feed-forward term represents a solution of trajectory generation problem and feedback term stands for a state controller. Both of these parts generally fall into the category of optimal control problems. The article focuses on the design of a finite-horizon linear quadratic controller and its application in 2-DOF structure with the use of customized LQR computation procedure, showing all necessary steps of the design, including source codes. It is proposed that the developed methodology is general and can be adopted for most of other nonlinear mechatronic systems, including unstable or non-minimum phase systems. This has been already tested successfully for models of both double and triple inverted pendulums. The functionality of the concept under real conditions can also be seen in Ozana (2018a) and Ozana (2018b) showing preliminary experiments with real apparatus

Molecular basis of the 14-3-3 protein-dependent activation of yeast neutral trehalase Nth1

The 14-3-3 proteins, a family of highly conserved scaffolding proteins ubiquitously expressed in all eukaryotic cells, interact with and regulate the function of several hundreds of partner proteins. Yeast neutral trehalases (Nth), enzymes responsible for the hydrolysis of trehalose to glucose, compared with trehalases from other organisms, possess distinct structure and regulation involving phosphorylation at multiple sites followed by binding to the 14-3-3 protein. Here we report the crystal structures of yeast Nth1 and its complex with Bmh1 (yeast 14-3-3 isoform), which, together with mutational and fluorescence studies, indicate that the binding of Nth1 by 14-3-3 triggers Nth1's activity by enabling the proper 3D configuration of Nth1's catalytic and calcium-binding domains relative to each other, thus stabilizing the flexible part of the active site required for catalysis. The presented structure of the Bmh1:Nth1 complex highlights the ability of 14-3-3 to modulate the structure of a multidomain binding partner and to function as an allosteric effector. Furthermore, comparison of the Bmh1:Nth1 complex structure with those of 14-3-3:serotonin N-acetyltransferase and 14-3-3:heat shock protein beta-6 complexes revealed similarities in the 3D structures of bound partner proteins, suggesting the highly conserved nature of 14-3-3 affects the structures of many client proteins