Pi State Research Articles

Characterizing ATP processing by the AAA+ protein p97 at the atomic level

The human enzyme p97 regulates various cellular pathways by unfolding hundreds of protein substrates in an ATP-dependent manner, making it an essential component of protein homeostasis and an impactful pharmacological target. The hexameric complex undergoes substantial conformational changes throughout its catalytic cycle. Here we elucidate the molecular motions that occur at the active site in the temporal window immediately before and after ATP hydrolysis by merging cryo-EM, NMR spectroscopy and molecular dynamics simulations. p97 populates a metastable reaction intermediate, the ADP·Pi state, which is poised between hydrolysis and product release. Detailed snapshots reveal that the active site is finely tuned to trap and eventually discharge the cleaved phosphate. Signalling pathways originating at the active site coordinate the action of the hexamer subunits and couple hydrolysis with allosteric conformational changes. Our multidisciplinary approach enables a glimpse into the sophisticated spatial and temporal orchestration of ATP handling by a prototype AAA+ protein.

Analysis of rescattering effects in 3pi final states

Decays into three particles are often described in terms of two-body resonances and a non-interacting spectator particle. To go beyond this simplest isobar model, crossed-channel rescattering effects need to be accounted for. We quantify the importance of these rescattering effects in three-pion systems for different decay masses and angular-momentum quantum numbers. We provide amplitude decompositions for four decay processes with total J^{PC} = 0^{--}, 1^{--}, 1^{-+}, and 2^{++}, all of which decay predominantly as rho pi states. Two-pion rescattering is described in terms of an Omnès function, which incorporates the rho resonance. Inclusion of crossed-channel effects is achieved by solving the Khuri–Treiman integral equations. The unbinned log-likelihood estimator is used to determine the significance of the rescattering effects beyond two-body resonances; we compute the minimum number of events necessary to unambiguously find these in future Dalitz-plot analyses. Kinematic effects that enhance or dilute the rescattering are identified for the selected set of quantum numbers and various masses.

The Proteome and Phosphoproteome Uncovers Candidate Proteins Associated With Vacuolar Phosphate Signal Multipled by Vacuolar Phosphate Transporter 1 (VPT1) in Arabidopsis

Plant vacuoles serve as the primary intracellular compartments for inorganic phosphate (Pi) storage. Passage of Pi across vacuolar membranes plays a critical role in buffering the cytoplasmic Pi level against fluctuations of external Pi and metabolic activities. To gain new insights into the proteins and processes, vacuolar Pi level regulated by vacuolar phosphate transporter 1 (VPT1) in Arabidopsis, we carried out tandem mass tag labeling proteome and phosphoproteome profiling of Arabidopsis WT and vpt1 loss-of-function mutant plants. The vpt1 mutant had a marked reduced vacuolar Pi level and a slight increased cytosol Pi level. The mutant was stunted as reflected in the reduction of the fresh weight compared with WT plants and bolting earlier under normal growth conditions in soil. Over 5566 proteins and 7965 phosphopeptides were quantified. About 146 and 83 proteins were significantly changed at protein abundance or site-specific phosphorylation levels, but only six proteins were shared between them. Functional enrichment analysis revealed that the changes of Pi states in vpt1 are associated with photosynthesis, translation, RNA splicing, and defense response, consistent with similar studies in Arabidopsis. Except for PAP26, EIN2, and KIN10, which were reported to be associated with phosphate starvation signal, we also found that many differential proteins involved in abscisic acid signaling, such as CARK1, SnRK1, and AREB3, were significantly changed in vpt1. Our study illuminates several new aspects of the phosphate response and identifies important targets for further investigation and potential crop improvement.

Multiple sub-state structures of SERCA2b reveal conformational overlap at transition steps during the catalytic cycle.

Sarco/endoplasmic reticulum Ca2+ ATPase (SERCA) pumps Ca2+ into the endoplasmic reticulum (ER). Herein, we present cryo-electron microscopy (EM) structures of three intermediates of SERCA2b: Ca2+-bound phosphorylated (E1P·2Ca2+) and Ca2+-unbound dephosphorylated (E2·Pi) intermediates and another between the E2P and E2·Pi states. Our cryo-EM analysis demonstrates that the E1P·2Ca2+ state exists in low abundance and preferentially transitions to an E2P-like structure by releasing Ca2+ and that the Ca2+ release gate subsequently undergoes stepwise closure during the dephosphorylation processes. Importantly, each intermediate adopts multiple sub-state structures including those like the next one in the catalytic series, indicating conformational overlap at transition steps, as further substantiated by atomistic molecular dynamic simulations of SERCA2b in a lipid bilayer. The present findings provide insight into how enzymes accelerate catalytic cycles.

Integration of hydrogen technology and energy management comparison for DC-Microgrid including renewable energies and energy storage system

Microgrids-based distributed energy resources DERs have an electrical revolution, especially in the electrification zones and clean energy. This paper proposes a comparative energy management study of an isolated direct current micro-grid DCMG, which consists of two primary sources, a photovoltaic PV and wind turbine WT generator working at the maximum power point MPP to extract the maximum available, then an energy storage system ESS-based lead-acid batteries to assuring the DC-bus stability. A backup device based on Proton Exchange Membrane Fuel Cell PEMFC to ensure the system’s reliability avoids the blackout scenario, adding to power electronic converters for the flexible relationship of the system elements, and a community residential as hybrid loads. This comparative study is based on classical techniques: classical PI CPI and state machine strategy SM; intelligent methods such as fuzzy logic rule FLC and artificial neural network ANN; moreover, two optimization methods equivalent consumption minimization strategy ECMS and external energy maximization strategy EEMS. The full Matlab/Simulink model has been developed to check the performance of the proposed system and energy management strategies for actual load and weather conditions. Simulation results based comparison show that the optimization methods are enhanced the system performance, DC-bus stability and minimize the overall system cost by reducing the hydrogen consumption.

High-yielding sugarcane in tropical Brazil – Integrating field experimentation and modelling approach for assessing variety performances

• Outstanding yields by cane varieties were obtained under unlimited conditions in large field experiments in tropical Brazil. • Guadalupe, PI State, is a more favourable production environment for sugarcane than São Romão, MG State. • The radiation use efficiency was similar between varieties up to 6–8 months regardless of site. • The radiation use efficiency declined differently among varieties after the onset of the growth slowdown. • Traits such as stalk fraction and growth slowdown with ageing were derived for use in modelling with the APSIM-Sugar model. Aiming to gain an understanding of how the genotype × environment × management (G×E×M) interaction influences the yield accumulation by elite sugarcane varieties in Brazil, a large dataset from field plot experiments carried out in two tropical sites (Guadalupe, 6.8 °S; São Romão, 16.4 °S) involving distinct planting dates, varieties and harvest ages, was analysed with statistical techniques and with the APSIM-Sugar model. Radiation use efficiency (RUE) was determined via a series of regressions and employed in an analysis of variance to investigate site, seasonal, developmental, and varietal differences. Outstanding yields were achieved at both sites. RUE declined as the crop progressed, confirming previous observations on declining RUE with age, known as the reduced growth phenomenon (RGP). RUE was always greater at Guadalupe than São Romão, evidencing that Guadalupe is a more suitable environment for sugarcane production, favoured by higher air temperatures during crop establishment and canopy formation. Varietal differences in RUE appeared only after the early developmental stage, and the observed growth slowdown with age was consistent across the two experimental sites, indicating that RGP is a varietal trait that should be considered for high-yielding environments. The process-based APSIM-Sugar model was set up with recently determined canopy traits and a new RGP feature based on leaf appearance. RGP parameters were obtained for each variety and site through calibration. The calibrated model was accurate to account for yield accumulation by the varieties in both experiments. The new parameters were evaluated with independent datasets from other local experiments at each tropical site as well as from published rainfed experiments in sub-tropical Southeast Brazil. Independent verification of the RGP traits added confidence in the new way of dealing with RGP based on leaf stage. The G×E×M interaction on yield accumulation can now be explored more confidently with APSIM-Sugar for the purpose of optimising the choice of varieties, planting dates and harvest ages for sugarcane industries in favourable irrigated lands in tropical Brazil.

The symptom-syndrome analysis of multivariate categorical data based on Zhegalkin polynomials

In this article, we study the distribution, entropy and other informational properties of finite projective subspaces (syndromes) parameterized by impulse sequences with basic elements in the form of symptoms - polynomials over the field F2 which are known as Zhegalkin polynomials. It has been proven that the super syndrome, which is a linear syndrome with basic elements in the form of a multiplicative syndrome, is closed. If in the multiplication of two symptoms one is neutral, then we are talking about its majorization. The ordered by majorization symptoms form a majorized syndrome. Is proved that the majorized syndrome is closed and coincides with the super syndrome. The statements formulated in the first part of the paper are used to justify the convergence of the iterative procedure (PI), in which the most informative symptoms selected from partial super syndromes are again used in the next step. The stationary state of PI is obtained if all elements of the input set belong to either the same partial super syndrome or to the majorized syndrome. Thanks IP it is possible to quickly find the optimal syndrome from a large set of variables. An example from phthisiology shows how the specificity of classification can be improved using symptom analysis.

Study of dynamics of the process e^+e^-rightarrow pi ^+pi ^-pi ^0 in the energy range 1.15\u20132.00 GeV

The dynamics of the process e^+e^- rightarrow pi ^+pi ^-pi ^0 is studied in the energy region from 1.15 to 2.00 GeV using data accumulated with the SND detector at the VEPP-2000 e^+e^- collider. The Dalitz plot distribution and pi ^+pi ^- mass spectrum are analyzed in a model including the intermediate states rho (770)pi , rho (1450)pi , and omega pi ^0. As a result, the energy dependences of the rho (770)pi and rho (1450)pi cross sections and the relative phases between the rho (770)pi amplitude and the rho (1450)pi and omega pi ^0 amplitudes are obtained. The rho (1450)pi cross section has a peak in the energy region of the omega (1650) resonance (1.55–1.75 GeV). In this energy range the contributions of the rho (770)pi and rho (1450)pi states are of the same order of magnitude. No resonance structure near 1.65 GeV is observed in the rho (770)pi cross section. We conclude that the intermediate state rho (1450)pi gives a significant contribution to the decay of omega (1650)rightarrow pi ^+pi ^-pi ^0, whereas the rho (770)pi mechanism dominates in the decay omega (1420)rightarrow pi ^+pi ^-pi ^0.

H∞ fuzzy proportional integral state feedback controller of photovoltaic systems under asymmetric actuator constraints

This paper presents a new strategy for a robust maximum power point (MPP) tracking fuzzy controller for photovoltaic (PV) systems subject to actuator asymmetric saturation. A DC-DC boost converter is used to connect a PV panel with an output load. The output voltage of the DC-DC boost converter can be adjusted by duty ratio that is limited between 0 and 1. The aim of our control design is to track the MPP under atmospheric condition changes and the presence of the asymmetric saturation of the duty ratio. To minimize tracking error and disturbance effect, the dynamic behaviour of a PV system and its reference model are described by using Takagi–Sugeno fuzzy models. Then, a constrained control based on a fuzzy PI state feedback controller is proposed. The H∞ control approach is used in control design and stability conditions of the closed-loop system are formulated and solved in terms of linear matrix inequalities. Finally, simulation results are given to show the tracking performance of the control design.

PID filter-shaped optimal PI tracker, state estimator, and EID estimator for continuous-time systems

This paper proposes a proportional–integral-differential (PID) filter-shaped optimal PI tracker for on-line robust optimal tracking control of a system with unknown disturbances. The proposed optimal PI tracker consists of both a modified state estimator and the newly modified equivalent input disturbance (EID) estimator. The main contributions of this paper are: (1) The conventional EID estimator is significantly modified to improve the tracking performances of a system with unknown disturbances; and (2) The improved EID estimator can be simply regarded as a plug-in component of the compensator, to perform on-line optimal tracking control of square/non-square servo systems with unknown disturbances.

Change in inorganic phosphate physical state can regulate transcription

ABSTRACTInorganic phosphate (Pi), a ubiquitous metabolite, is involved in all major biochemical pathways. We demonstrate that, in vitro, MgHPO4 (the intracellular Pi form) at physiological concentrations can exist in a metastable supersaturated dissolved state or as a precipitate. We have shown that in solution, MgHPO4 strongly stimulates exonuclease nascent transcript cleavage by RNA polymerase. We report here that MgHPO4 precipitate selectively and efficiently inhibits transcription initiation in vitro. In view of the MgHPO4 solubility and in vitro sensitivity of RNA synthesis to MgHPO4 precipitate, at physiological concentrations, MgHPO4 should cause a 50–98% inhibition of cellular RNA synthesis, thus exerting a strong regulatory action. The effects of Pi on transcription in vivo will, therefore, reflect the physical state of intracellular Pi.

Mass-independent dunham analysis of the [7.7] Y2Σ+ – X2Πi and [16.3] A2Σ− – X2Πi transitions of copper monoxide, CuO

The electronic spectrum of CuO has been studied extensively experimentally. In his review on the spectroscopy of the 3d transition metal oxides (Merer, 1989), Anthony Merer summarized the available experimental data for CuO, which encompassed over 20 publications. There have been 4 subsequent publications on CuO that have included: high resolution Fourier-Transform emission spectroscopy (FTS) (O’Brien et al., 1996), mm- and sub-mm microwave absorption spectroscopy (Steimle et al., 1997), moderate resolution laser induced fluorescence (LIF) spectroscopy (Jin et al., 2002), and high-resolution molecular beam LIF spectroscopy, both in the presence and absence of an external electric field (Zhuang et al., 2010). Despite this extensive study, analyses of spectra have been restricted to 63CuO, even though the natural abundance of 65Cu is significant (63Cu:65Cu is 69%:31%). Additionally, the Λ-doubling parameter for the X 2Πi state of CuO is assigned a negative sign in the FTS analysis, but is assigned a positive sign in the microwave and molecular beam LIF analyses. In this study, high resolution spectra for (0,0) and (1,1) bands of the [16.3] A2Σ− – X2Πi transition of CuO have been recorded using intracavity laser absorption spectroscopy (ILS). Features due to the (0,0) band of 65CuO were clearly identified in the spectra and included in the analysis. The CuO FTS spectrum was retrieved from the archive for the McMath-Pierce Solar Observatory at Kitt Peak, and several additional vibrational bands of the [7.7] Y2Σ+ – X2Πi transition of CuO were identified in the FTS data, including the (1,0), (0,0), and (0,1) bands of 65CuO. The ILS, FTS, microwave and molecular beam LIF data were simultaneously fit to a mass-independent Dunham type Hamiltonian using PGOPHER. In total, 13,019 observations were fit to 1 constrained and 46 floated parameters. The results of this simultaneous fit show a Cu-isotope dependent shift in electronic energy for the [7.7] Y2Σ+ – X2Πi and [16.3] A2Σ− – X2Πi transitions of CuO. The results also confirm that the sign of q in the X 2Πi ground state is negative. Potential energy curves were generated from the molecular constants obtained in the fit for the [7.7] Y2Σ+ and X 2Πi states using the RKR method. These potential energy curves are significantly different and clearly indicate the Y and X state do not form a pure-precession pair.

Switch effect and 0- π transition in Ising superconductor Josephson junctions

We theoretically study the Josephson current in Ising superconductor-half-metal-Ising superconductor junctions. By solving the Bogoliubov-de Gennes equations, the Josephson currents contributed by the discrete Andreev levels and the continuous spectrum are obtained. For very short junctions, because the direct tunneling of the Cooper pair dominates the Josephson current, the current-phase difference relation is independent of the magnetization direction, which is the same as the conventional superconductor-ferromagnet-superconductor junctions. On the other hand, when the length of the half-metal is similar to or greater than the superconducting coherence length, the spin-triplet Josephson effect occurs and dominates the Josephson current. In this case, the current-phase difference relations show the strong magnetoanisotropic behaviors with the period \pi. When the magnetization direction points to the $\pm$ z directions, the current is zero regardless of the phase difference. However, the current has a large value when the magnetization direction is parallel to the junction plane, which leads to a perfect switch effect of the Josephson current. Furthermore, we find that the long junctions can host both the 0 state and \pi state, and the $0$-$\pi$ transitions can be achieved with the change of the magnetization direction. The physical origins of the switch effect and $0$-$\pi$ transitions are interpreted from the perspectives of the spin-triplet Andreev reflection, the Ising pairing order parameter and the Ginzburg-Landau type of free energy. In addition, the influences of the chemical potential, the magnetization magnitude, and the strength of the Ising spin-orbit coupling on the switch effect and $0$-$\pi$ transitions are also investigated. Furthermore, the two-dimensional Josephson junctions are also investigated and we show that the spin-triplet Josephson effect can exist always.

The role of tubulin-tubulin lattice contacts in the mechanism of microtubule dynamic instability.

Microtubules form from longitudinally and laterally assembling tubulin α/β-dimers. The assembly induces strain in tubulin, resulting in cycles of microtubule catastrophe and regrowth. This so-called dynamic instability is governed by GTP hydrolysis that renders the microtubule lattice unstable, but it is unclear how. We used the human microtubule nucleating and stabilising neuronal protein doublecortin and high-resolution cryo-EM to capture tubulin’s elusive hydrolysis intermediate GDP.Pi state, alongside the pre-hydrolysis analogue GMPCPP state, and the post-hydrolysis GDP state with and without an anti-cancer drug Taxol®. GTP hydrolysis to GDP.Pi, followed by Pi release, constitute distinct structural transitions, causing unevenly distributed compressions of tubulin dimers, thereby tightening longitudinal and loosening lateral inter-dimer contacts. We conclude that microtubule catastrophe is triggered because the lateral contacts can no longer counteract the strain energy stored in the lattice, while reinforcement of the longitudinal contacts may support generation of force.

Two-level energy management strategy for PV-Fuel cell-battery-based DC microgrid

With the fast development of DC Microgrid (MG) technology, its operating economy and reliability are getting more and more concern. The traditional distributed control method is aimed at power balance and system stability, and is difficult to meet the requirement of energy management system for multi-source hybrid DC MG. This paper provides a two-level energy management strategy for PV-fuel cell-battery-based DC MG, which is divided into device control level and system control level. At the device control level, the distributed control methods based on MPPT-droop dual-mode control and droop control are proposed to enhance system reliability; at the system control level, the equivalent consumption minimization strategy (ECMS) is used to distribute system net power between battery pack and fuel cell system. A lab-scale DC microgrid platform is developed to verify the proposed energy management strategy in this paper. Moreover, the analysis and compare of the results show that the proposed two-level energy management strategy can achieve lower equivalent hydrogen consumption than classical PI control and state machine control method.

Collisional radiative model for Ar-O2 mixture plasma with fully relativistic fine structure cross sections

A collisional radiative (C-R) model has been developed to diagnose the rf generated Ar-O2 (0%–5%) mixture plasma at low temperatures. Since in such plasmas the most dominant process is an electron impact excitation process, we considered several electron impact fine structure transitions in an argon atom from its ground as well as excited states. The cross-sections for these transitions have been obtained using the reliable fully relativistic distorted wave theory. Processes which account for the coupling of argon with the oxygen molecules have been further added to the model. We couple our model to the optical spectroscopic measurements reported by Jogi et al. [J. Phys. D: Appl. Phys. 47, 335206 (2014)]. The plasma parameters, viz. the electron density (ne) and the electron temperature (Te) as a function of O2 concentration have been obtained using thirteen intense emission lines out of 3p54p → 3p54s transitions observed in their spectroscopic measurements. It is found that as the content of O2 in Ar increases from 0%–5%, Te increases in the range 0.85–1.7 eV, while the electron density decreases from 2.76 × 1012–2.34 × 1011 cm−3. The Ar-3p54s (1si) fine-structure level populations at our extracted plasma parameters are found to be in very good agreement with those obtained from the measurements. Furthermore, we have estimated the individual contributions coming from the ground state, 1si manifolds and cascade contributions to the population of the radiating Ar-3p54p (2pi) states as a function of a trace amount of O2. Such information is very useful to understand the importance of various processes occurring in the plasma.

Energy and radiative properties of the (3)Π1 and (5)Σ+1 states of RbCs: Experiment and theory

We combined high-resolution Fourier-transform spectroscopy and large-scale electronic structure calculation to study energy and radiative properties of the high-lying (3)1{\Pi} and (5)1{\Sigma}+ states of the RbCs molecule. The laser-induced (5)1{\Sigma}+(4)1{\Sigma}+(3)1{\Pi}-A(2)1{\Sigma}+ b(1)3{\Pi} fluorescence (LIF) spectra were recorded by the Bruker IFS-125(HR) spectrometer in the frequency range {\nu} 5500 to 10000cm-1 with the instrumental resolution of 0.03 cm-1. The rotational assignment of the observed LIF progressions, which exhibit irregular vibrational-rotational spacing due to strong spin-orbit interaction between A1{\Sigma}+ and b3(\Pi) states was based on the coincidences between observed and calculated energy differences. The required rovibronic term values of the strongly perturbed A-b complex have been calculated by a coupled-channels approach for both 85Rb133Cs and 87Rb133Cs isotopologs with accuracy of about 0.01 cm-1, as demonstrated in A. Kruzins et al. [J. Chem. Phys. 141, 184309 (2014)]. The experimental energies of the upper (3)1(\Pi) and (5)1{\Sigma}+ states were involved in a direct-potential-fit analysis performed in the framework of inverted perturbation approach. Quasirelativistic ab initio calculations of the spin-allowed (3)1{\Pi},(5)1{\Sigma}+- (1-4)1{\Sigma}+(1-3)1{\Pi} transition dipole moments were performed. Radiative lifetimes and vibronic branching ratios of radiative transitions from the (3)1{\Pi} and (5)1{\Sigma}+ states were evaluated. To elucidate the origin of the {\Lambda}-doubling effect in the (3)1{\Pi} state, the angular coupling (3)1{\Pi}-(1-5)1{\Sigma}+ electronic matrix elements were calculated and applied for the relevant q-factors estimate. The intensity distributions simulated for the particular (5)1{\Sigma}+(3)1{\Pi}-A-b LIF progressions have been found to be remarkably close to their experimental counterparts.

Vtc5, a Novel Subunit of the Vacuolar Transporter Chaperone Complex, Regulates Polyphosphate Synthesis and Phosphate Homeostasis in Yeast

SPX domains control phosphate homeostasis in eukaryotes. Ten genes in yeast encode SPX-containing proteins, among which YDR089W is the only one of unknown function. Here, we show that YDR089W encodes a novel subunit of the vacuole transporter chaperone (VTC) complex that produces inorganic polyphosphate (polyP). The polyP synthesis transfers inorganic phosphate (Pi) from the cytosol into the acidocalcisome- and lysosome-related vacuoles of yeast, where it can be released again. It was therefore proposed for buffer changes in cytosolic Pi concentration (Thomas, M. R., and O'Shea, E. K. (2005) Proc. Natl. Acad. Sci. U.S.A. 102, 9565-9570). Vtc5 physically interacts with the VTC complex and accelerates the accumulation of polyP synthesized by it. Deletion of VTC5 reduces polyP accumulation in vivo and in vitro Its overexpression hyperactivates polyP production and triggers the phosphate starvation response via the PHO pathway. Because this Vtc5-induced starvation response can be reverted by shutting down polyP synthesis genetically or pharmacologically, we propose that polyP synthesis rather than Vtc5 itself is a regulator of the PHO pathway. Our observations suggest that polyP synthesis not only serves to establish a buffer for transient drops in cytosolic Pi levels but that it can actively decrease or increase the steady state of cytosolic Pi.

Fundamental Entangling Operators in Quantum Mechanics and Their Properties

For the first time, we introduce so-called fundamental entangling operators \(e^{iQ_{1} P_{2}}\) and \(e^{iP_{1} Q_{2} }\) for composing bipartite entangled states of continuum variables, where Qi and Pi (i = 1, 2) are coordinate and momentum operator, respectively. We then analyze how these entangling operators naturally appear in the quantum image of classical quadratic coordinate transformation (q1, q2) → (Aq1 + Bq2, Cq1 + Dq2), where AD−BC = 1, which means even the basic coordinate transformation (Q1, Q2) → (AQ1 + BQ2, CQ1 + DQ2) involves entangling mechanism. We also analyse their Lie algebraic properties and use the integration technique within an ordered product of operators to show they are also one- and two- mode combinatorial squeezing operators.

Nonlinear Observer-Based Ship Control and Disturbance Compensation

Abstract: In this paper, a gain-scheduled nonlinear control structure is proposed for a surface vessel, which takes advantage of extended linearisation techniques. Thereby, an accurate tracking of desired trajectories can be guaranteed that contributes to a safe and reliable water transport. The PI state feedback control is extended by a feedforward control based on an inverse system model. To achieve an accurate trajectory tracking, however, an observer-based disturbance compensation is necessary: external disturbances by cross currents or wind forces in lateral direction and wave-induced measurement disturbances are estimated by a nonlinear observer and used for a compensation. The efficiency and the achieved tracking performance are shown by simulation results using a validated model of the ship Korona at the HTWG Konstanz, Germany. Here, both tracking behaviour and rejection of disturbance forces in lateral direction are considered.