Search

Nonlinear effects and external disturbances can severely impact the control of an autonomous race car at the handling limits. State-of-the-art approaches do not take these uncertainties explicitly into account in the design process and are therefore prone to failure. To overcome this limitation, we present a robust control design based on tube model predictive control (TMPC). It is based on a simplified friction limited point-mass model and an additive disturbance for the lateral and longitudinal dynamics. Instead of nominal predictions, it leverages an approximate tube of reachable sets over the prediction horizon to guarantee constraint satisfaction. The resulting optimisation problem can be posed in the form of a standard quadratic programme by tightening the input and state constraints. The computational burden is therefore the same as in the nominal case. We benchmark our controller on a Hardware-in-the-Loop testbench with a nonlinear dual-track model and a combined Pacejka tyre model. The results demonstrate that the TMPC controller reduces the constraint violations while achieving comparable lap-times in contrast to an MPC controller and an infinite time LQR controller. It manages to apply caution when needed while maintaining a similar level of performance and is therefore considered to be superior in practical applications. [ABSTRACT FROM AUTHOR]

Molecular mechanisms enabling the switching and maintenance of epigenetic states are not fully understood. Distinct histone modifications are often associated with ON/OFF epigenetic states, but how these states are stably maintained through DNA replication, yet in certain situations switch from one to another remains unclear. Here, we address this problem through identification of Arabidopsis INCURVATA11 (ICU11) as a Polycomb Repressive Complex 2 accessory protein. ICU11 robustly immunoprecipitated in vivo with PRC2 core components and the accessory proteins, EMBRYONIC FLOWER 1 (EMF1), LIKE HETEROCHROMATIN PROTEIN1 (LHP1), and TELOMERE_REPEAT_BINDING FACTORS (TRBs). ICU11 encodes a 2-oxoglutarate-dependent dioxygenase, an activity associated with histone demethylation in other organisms, and mutant plants show defects in multiple aspects of the Arabidopsis epigenome. To investigate its primary molecular function we identified the Arabidopsis FLOWERING LOCUS C ( FLC ) as a direct target and found icu11 disrupted the cold-induced, Polycomb-mediated silencing underlying vernalization. icu11 prevented reduction in H3K36me3 levels normally seen during the early cold phase, supporting a role for ICU11 in H3K36me3 demethylation. This was coincident with an attenuation of H3K27me3 at the internal nucleation site in FLC , and reduction in H3K27me3 levels across the body of the gene after plants were returned to the warm. Thus, ICU11 is required for the cold-induced epigenetic switching between the mutually exclusive chromatin states at FLC , from the active H3K36me3 state to the silenced H3K27me3 state. These data support the importance of physical coupling of histone modification activities to promote epigenetic switching between opposing chromatin states., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

A large fraction of plant genomes is composed of transposable elements (TE), which provide a potential source of novel genes through "domestication"-the process whereby the proteins encoded by TE diverge in sequence, lose their ability to catalyse transposition and instead acquire novel functions for their hosts. In Arabidopsis, ANTAGONIST OF LIKE HETEROCHROMATIN PROTEIN 1 (ALP1) arose by domestication of the nuclease component of Harbinger class TE and acquired a new function as a component of POLYCOMB REPRESSIVE COMPLEX 2 (PRC2), a histone H3K27me3 methyltransferase involved in regulation of host genes and in some cases TE. It was not clear how ALP1 associated with PRC2, nor what the functional consequence was. Here, we identify ALP2 genetically as a suppressor of Polycomb-group (PcG) mutant phenotypes and show that it arose from the second, DNA binding component of Harbinger transposases. Molecular analysis of PcG compromised backgrounds reveals that ALP genes oppose silencing and H3K27me3 deposition at key PcG target genes. Proteomic analysis reveals that ALP1 and ALP2 are components of a variant PRC2 complex that contains the four core components but lacks plant-specific accessory components such as the H3K27me3 reader LIKE HETEROCHROMATION PROTEIN 1 (LHP1). We show that the N-terminus of ALP2 interacts directly with ALP1, whereas the C-terminus of ALP2 interacts with MULTICOPY SUPPRESSOR OF IRA1 (MSI1), a core component of PRC2. Proteomic analysis reveals that in alp2 mutant backgrounds ALP1 protein no longer associates with PRC2, consistent with a role for ALP2 in recruitment of ALP1. We suggest that the propensity of Harbinger TE to insert in gene-rich regions of the genome, together with the modular two component nature of their transposases, has predisposed them for domestication and incorporation into chromatin modifying complexes., Competing Interests: The authors have declared that no competing interests exist.

The dihedral angle between the benzene and thio-phene rings in the title compound, C(12)H(10)N(2)O(3)S, is 27.94 (13)°. An inter-molecular C-H⋯π inter-action contributes to the stability of the crystal structure.

Objective: The purpose of this study was to determine the effect of different colour nail polishes and henna on the measurement of oxygen saturation and the differences among the measurements of three pulse oximetry devices., Material and Methods: 33 healthy females with a mean age of 19±1.0 years and no complaints or known disease were included into the study. All the participants applied henna to one of their fingers a day before the study. Just before the study, one finger was left empty as control and the other fingers were dyed using various colours of nail polish (red, blue, beige, purple, brown, white, pink, green, colourless polish, light blue, light green and yellow). There were more than eight colour nail polishes and some fingers were used for the other colours after being completely cleaned. The same brand nail polishes were used for the study. Oxygen saturation measurements were done using three different pulse oximetry devices (device I, II, III) from the control, different colour nail polished and henna applied fingers. The measurements of different devices, different colour nail polishes, henna and control were statistically compared., Results: The mean saturations obtained from blue, beige, purple and white nail polished fingers were significantly lower than those of control and the other coloured fingers. In addition, the mean measurement of device II was significantly lower than those of other devices., Conclusion: The results suggest that blue, beige, purple and white nail polished fingers might cause pulse oximetry devices to make incorrect measurements.

Dwindling petroleum feedstocks and increased CO(2)-concentrations in the atmosphere currently open the concept of using CO(2) as raw material for the synthesis of well-defined organic compounds. In parallel to recent advances in the chemical CO(2)-fixation, enzymatic (biocatalytic) carboxylation is currently being investigated at an increased pace. On the one hand, this critical review provides a concise overview on highly specific biosynthetic pathways for CO(2)-fixation and, on the other hand, a summary of biodegradation (detoxification) processes involving enzymes which possess relaxed substrate specificities, which allow their application for the regioselective carboxylation of organic substrates to furnish the corresponding carboxylic acids (145 references).