Position error estimation of the underwater coordinate measurement machine using artificial neural network

Position error of the underwater coordinate measurement machine (UWCMM) is estimated using an artificial neural network (ANN). The UWCMM has a multi joint serial link and the position of an underwater robot attached to the tip is obtained from kinematics of the link. However, the inaccuracy of the kinematics model creates a position error. In order to improve measurement accuracy, an ANN model which estimate position error of the kinematics of the UWCMM using joint angles data is constructed. The ANN model was trained by 462 data and verified by 42 data. The error estimation result of the trained ANN reduces maximally 66.5 % of the average of the position error of the verification data

Dynamic structure of pharaonis phoborhodopsin (sensory rhodopsin II) and complex with a cognate truncated transducer as revealed by site-directed 13C solid-state NMR

AbstractWe have recorded 13C nuclear magnetic resonance (NMR) spectra of [3-13C]Ala, [1-13C]Val-labeled pharaonis phoborhodopsin (ppR or sensory rhodopsin II) incorporated into egg PC (phosphatidylcholine) bilayer, by means of site-directed high-resolution solid-state NMR techniques. Seven 13C NMR signals from transmembrane α-helices were resolved for [3-13C]Ala-ppR at almost the same positions as those of bacteriorhodopsin (bR), except for the suppressed peaks in the loop regions in spite of the presence of at least three Ala residues. In contrast, 13C NMR signals from the loops were visible from [1-13C]Val-ppR but their peak positions of the transmembrane α-helices are not always the same between ppR and bR. The motional frequency of the loop regions in ppR was estimated as 105 Hz in view of the suppressed peaks from [3-13C]Ala-ppR due to interference with proton decoupling frequency. We found that conformation and dynamics of ppR were appreciably altered by complex formation with a cognate truncated transducer pHtr II (1–159). In particular, the C-terminal α-helix protruding from the membrane surface is involved in the complex formation and subsequent fluctuation frequency is reduced by one order of magnitude

Prime Focus Spectrograph (PFS) for the Subaru Telescope: Overview, recent progress, and future perspectives

PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ~1.6-2.7A. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The project is now going into the construction phase aiming at undertaking system integration in 2017-2018 and subsequently carrying out engineering operations in 2018-2019. This article gives an overview of the instrument, current project status and future paths forward.Comment: 17 pages, 10 figures. Proceeding of SPIE Astronomical Telescopes and Instrumentation 201

Metrology camera system of prime focus spectrograph for Subaru telescope

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. PFS will cover a 1.3 degree diameter field with 2394 fibers to complement the imaging capabilities of Hyper SuprimeCam. To retain high throughput, the final positioning accuracy between the fibers and observing targets of PFS is required to be less than 10 μm. The metrology camera system (MCS) serves as the optical encoder of the fiber positioners for the configuring of fibers. MCS provides the fiber positions within a 5 microns error over the 45 cm focal plane. The information from MCS will be fed into the fiber positioner control system for the closed loop control. MCS locates at the Cassegrain focus of Subaru telescope to cover the whole focal plan with one 50M pixel Canon CMOS camera. It is a 380 mm aperture Schmidt type telescope which generates uniform spot size around 10 µm FWHM across the field for reasonable sampling of the point spreading function. An achromatic lens set is designed to remove the possible chromatic error due to the variation of the LED wavelength. Carbon fiber tubes are used to provide stable structure over the operation conditions without focus adjustments. The CMOS sensor can be read in 0.8 s to reduce the overhead for the fiber configuration. The positions of all fibers can be obtained within 0.5 s after the readout of the frame. This enables the overall fiber configuration to be less than 2 minutes. MCS is installed inside a standard Subaru Cassgrain Box. All components generate heat are located inside a glycol cooled cabinet to reduce the possible image motion due to the heat. The integration of MCS started from fall 2017 and it was delivered to Subaru in April 2018. In this report, the performance of MCS after the integration and verification process in ASIAA and the performance after the delivery to Subaru telescope are presented

The Hyper Suprime-Cam SSP survey: Overview and survey design

Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg2 in five broad bands (grizy), with a 5 σ point-source depth of r ≈ 26. The Deep layer covers a total of 26 deg2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey

Association of pharaonis phoborhodopsin with its cognate transducer decreases the photo-dependent reactivity by water-soluble reagents of azide and hydroxylamine.

pharaonis phoborhodopsin (ppR; also pharaonis sensory rhodopsin II, psRII) is a receptor of the negative phototaxis of Natronobacterium pharaonis. In halobacterial membrane, ppR forms a complex with its transducer pHtrII, and this complex transmits the light signal to the sensory system in the cytoplasm. In the present work, the truncated transducer, t-Htr, was used which interacts with ppR [Sudo et al. (2001) Photochem. Photobiol. 74, 489–494]. Two water-soluble reagents, hydroxylamine and azide, reacted both with the transducer-free ppR and with the complex ppR/t-Htr (the complex between ppR and its truncated transducer). In the dark, the bleaching rates caused by hydroxylamine were not significantly changed between transducer-free ppR and ppR/t-Htr, or that of the free ppR was a little slower. Illumination accelerated the bleach rates, which is consistent with our previous conclusion that the reaction occurs selectively at the M-intermediate, but the rate of the complex was about 7.4-fold slower than that of the transducer-free ppR. Azide accelerated the M-decay, and its reaction rate of ppR/t-Htr was about 4.6-fold slower than free ppR. These findings suggest that the transducer binding decreases the water accessibility around the chromophore at the M-intermediate. Its implication is discussed

Association between a photo-intermediate of a M-lacking mutant D75N of pharaonis phoborhodopsin and its cognate transducer.

Pharaonis phoborhodopsin (ppR or pharaonis sensory rhodopsin II) is a receptor of the negative phototaxis of Natronobacterium pharaonis and forms a complex with its transducer pHtrII in membranes. Flash-photolyis of a D75N mutant did not yield the M-intermediate, but an O-like intermediate is observed in a ms time range. We examined the interaction between the D75N of ppR and t-Htr (truncated pHtrII). These formed a complex in the presence of 0.1% n-dodecyl-β-maltoside, and the association accelerated the decay of the O of D75N from 15 to 56 s−1. From the decay time constants under varying ratios of D75N and t-Htr, n, the molar ratio of D75N/t-Htr in the complex, and KD, the dissociation constant, were estimated. The value of n was unity and KD was estimated to 146 nM. This KD value can be considered to be the association between the photo-intermediate and t-Htr, which is deduced by the method of estimation. Previously we (Photochem. Photobiol. 74 (2001) 489) reported a KD of 15 μM for the interaction between the wild-type and t-Htr by means of the change in M-decay rates. Therefore, this value should be the KD value for the interaction between M of the wild-type and t-Htr

Selective reaction of hydroxylamine with chromophore during the photocycle of pharaonis phoborhodopsin.

Phoborhodopsin (pR; also called sensory rhodopsin II, sRII) is a receptor of negative phototaxis of Halobacterium salinarum, and pharaonis phoborhodopsin (ppR; also pharaonis sensory rhodopsin II, psRII) is a corresponding protein of Natronobacterium pharaonis. These receptors contain retinal as a chromophore which binds to a lysine residue via Schiff base. This Schiff base can be cleaved with hydroxylamine to loose their color (bleaching). In dark, the bleaching rate of ppR was very slow whereas illumination accelerated considerably the bleaching rate. Addition of azide accelerated the decay of the M-intermediate while its formation (decay of the L-intermediate) is not affected. The bleaching rate of ppR under illumination was decreased by addition of azide. Essentially no reactivity with hydroxylamine under illumination was observed in the case of D75N mutant which lacks the M-intermediate in its photocycle. Moreover, we provided illumination by flashes to ppR in the presence of varying concentrations of azide to measure the bleaching rate per one flash. A good correlation was obtained between the rate and the mean residence time, MRT, which was calculated from flash photolysis data of the M-decay. These findings reveal that water-soluble hydroxylamine reacts selectively with the M-intermediate and its implication was discussed

Role of Asp193 in chromophore-protein interaction of pharaonis phoborhodopsin (sensory rhodopsin II).

Pharaonis phoborhodopsin (ppR; also pharaonis sensory rhodopsin II, psRII) is a receptor of the negative phototaxis of Natronobacterium pharaonis. By spectroscopic titration of D193N and D193E mutants, the pKa of the Schiff base was evaluated. Asp193 corresponds to Glu204 of bacteriorhodopsin (bR). The pKa of the Schiff base (SBH+) of D193N was ~10.1-10.0 (at XH+) and ~11.4-11.6 (at X) depending on the protonation state of a certain residue (designated by X) and independent of Cl, whereas those of the wild type and D193E were >12. The pKa values of XH+ were ~11.8-11.2 at the state of SB, 10.5 at SBH+ state in the presence of Cl, and 9.6 at SBH+ without Cl. These imply the presence of a long-range interaction in the extracellular channel. Asp193 was suggested to be deprotonated in the present dodecyl-maltoside (DDM) solubilized wild-type ppR, which is contrary to Glu204 of bR. In the absence of salts, the irreversible denaturation of D193N (but not the wild type and D193E) occurred via a metastable state, into which the addition of Cl reversed the intact pigment. This suggests that the negative charge at residue 193, which can be substituted by Cl, is necessary to maintain the proper conformation in the DDM-solubilized ppR