Towards Holographic Spintronics

We study transport phenomena of total angular momentum in holography, as a first step toward holographic understanding of spin transport phenomena. Spin current, which has both the local Lorentz index for spins and the space-time vector index for current, couples naturally to the bulk spin connection. Therefore the bulk spin connection becomes the source for the boundary spin current. This allows us to evaluate the spin current holographically, with a relation to the stress tensor and metric fluctuations in the bulk. We examine the spin transport coefficients and the thermal spin Hall conductivity in a simple holographic setup.Comment: 9 pages, 3 figures. v2: minor improvements, published versio

Single-molecule fluorescence polarization study of conformational change in archaeal group II chaperonin.

Group II chaperonins found in archaea and in eukaryotic cytosol mediate protein folding without a GroES-like cofactor. The function of the cofactor is substituted by the helical protrusion at the tip of the apical domain, which forms a built-in lid on the central cavity. Although many studies on the change in lid conformation coupled to the binding and hydrolysis of nucleotides have been conducted, the molecular mechanism of lid closure remains poorly understood. Here, we performed a single-molecule polarization modulation to probe the rotation of the helical protrusion of a chaperonin from a hyperthermophilic archaeum, Thermococcus sp. strain KS-1. We detected approximately 35° rotation of the helical protrusion immediately after photorelease of ATP. The result suggests that the conformational change from the open lid to the closed lid state is responsible for the approximately 35° rotation of the helical protrusion

Single-molecule imaging of full protein synthesis by immobilized ribosomes

How folding of proteins is coupled to their synthesis remains poorly understood. Here, we apply single-molecule fluorescence imaging to full protein synthesis in vitro. Ribosomes were specifically immobilized onto glass surfaces and synthesis of green fluorescent protein (GFP) was achieved using modified commercial Protein Synthesis using Recombinant Elements that lacked ribosomes but contained purified factors and enzyme that are required for translation in Escherichia coli. Translation was monitored using a GFP mutant (F64L/S65T/F99S/M153T/V163A) that has a high fluorophore maturation rate and that contained the Secretion Monitor arrest sequence to prevent dissociation from the ribosome. Immobilized ribosomal subunits were labeled with Cy3 and GFP synthesis was measured by colocalization of GFP fluorescence with the ribosome position. The rate of appearance of colocalized ribosome GFP was equivalent to the rates of fluorescence appearance coupled with translation measured in bulk, and the ribosome–polypeptide complexes were stable for hours. The methods presented here are applicable to single-molecule investigation of translational initiation, elongation and cotranslational folding

Hitomi (ASTRO-H) X-ray Astronomy Satellite

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E  >  2  keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month

Comparison of Morning Heart Rate Variability at the Beginning and End of a Competition Season in Elite Speed Skaters

The aim of this study was to clarify whether the physiological fatigue status of elite speed skaters is influenced by the approximately five-month international competition season by comparing morning heart rate variability (HRV) at the beginning of the competition season (Japan Single Distances Championships: JSDC) with that at the end of the competition season (World Single Distances Championships: WSDC). Five international-class speed skaters participated in the study. HRV indices and subjective fatigue were measured each morning of the four days prior to the first races of the JSDC and WSDC in the 2007/2008 season. The parasympathetic HRV indices: root mean square of the successive R-R interval differences (RMSSD) (JSDC, 61.0 ms; WSDC, 42.1 ms; p < 0.05), high-frequency component power (HF) (JSDC, 1393 ms2; WSDC, 443 ms2; p < 0.05), and normalized unit of HF (HFnu) (JSDC, 53.2%; WSDC, 25.5%; p < 0.05) were lower for the WSDC than for the JSDC. The decrease in these indices may reflect the skaters’ accumulated fatigue during the course of the competition season. Morning measurements of HRV may thus be an efficient way for elite speed skaters and coaches to objectively monitor physiological fatigue throughout the competition season

Unconscious learning of auditory discrimination using mismatch negativity (MMN) neurofeedback

Neurofeedback is a strong direct training method for brain function, wherein brain activity patterns are measured and displayed as feedback, and trainees try to stabilize the feedback signal onto certain desirable states to regulate their own mental states. Here, we introduce a novel neurofeedback method, using the mismatch negativity (MMN) responses elicited by similar sounds that cannot be consciously discriminated. Through neurofeedback training, without participants' attention to the auditory stimuli or awareness of what was to be learned, we found that the participants could unconsciously achieve a significant improvement in the auditory discrimination of the applied stimuli. Our method has great potential to provide effortless auditory perceptual training. Based on this method, participants do not need to make an effort to discriminate auditory stimuli, and can choose tasks of interest without boredom due to training. In particular, it could be used to train people to recognize speech sounds that do not exist in their native language and thereby facilitate foreign language learning

Self-Produced Tickle Sensation by Manipulating Visual Feedback

The aim of the present paper was to clarify how the distinction of self- (sense of agency, SOA) and other-produced behavior can be synthesized and recognized in multisensory integration as our cognitive processes. To address this issue, we used tickling paradigm that it is hard for us to tickle ourselves. Previous studies show that tickle sensation by their own motion increases if more delay is given between self-motion of tickling and tactile stimulation (Blakemore et al. 1998, 1999). We introduced visual feedbacks to the tickling experiments. In our hypothesis, integration of vision, proprioception, and motor commands forms the SOA and disintegration causes the breakdown the SOA, which causes the feeling of others, producing tickling sensation even by tickling oneself. We used video-see-through HMD to suddenly delay the real-time images of their hand tickling motions. The tickle sensation was measured by subjective response in the following conditions; 1) tickling oneself without any visual modulation, 2) tickled by others, 3) tickling oneself with visual feedback manipulation. The statistical analysis of ranked evaluation of tickle sensations showed that the delay of visual feedback causes the increase of tickle sensation. The SOA was discussed with Blakemore's and our results