A Probabilistic Rotation Representation for Symmetric Shapes With an Efficiently Computable Bingham Loss Function

In recent years, a deep learning framework has been widely used for object pose estimation. While quaternion is a common choice for rotation representation, it cannot represent the ambiguity of the observation. In order to handle the ambiguity, the Bingham distribution is one promising solution. However, it requires complicated calculation when yielding the negative log-likelihood (NLL) loss. An alternative easy-to-implement loss function has been proposed to avoid complex computations but has difficulty expressing symmetric distribution. In this paper, we introduce a fast-computable and easy-to-implement NLL loss function for Bingham distribution. We also create the inference network and show that our loss function can capture the symmetric property of target objects from their point clouds.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible. arXiv admin note: substantial text overlap with arXiv:2203.0445

Stress resistance and C1 metabolism involved in plant colonization of a methanotroph Methylosinus sp. B4S.

Methanotrophs are widespread and have been isolated from various environments including the phyllosphere. In this study, we characterized the plant colonization by Methylosinus sp. B4S, an α-proteobacterial methanotroph isolated from plant leaf. The gfp-tagged Methylosinus sp. B4S cells were observed to colonize Arabidopsis leaf surfaces by forming aggregates. We cloned and sequenced the general stress response genes, phyR, nepR and ecfG, from Methylosinus sp. B4S. In vitro analysis showed that the phyR expression level was increased after heat shock challenge, and phyR was shown to be involved in resistance to heat shock and UV light. In the phyllospheric condition, the gene expression level of phyR as well as mmoX and mxaF was found to be relatively high, compared with methane-grown liquid cultures. The phyR-deletion strain as well as the wild-type strain inoculated on Arabidopsis leaves proliferated at the initial phase and then gradually decreased during plant colonization. These results have shed light firstly on the importance of general stress resistance and C1 metabolism in methanotroph living in the phyllosphere

Glucocorticoid Generates ROS to Induce Oxidative Injury in the Hippocampus, Leading to Impairment of Cognitive Function of Rats

The present study attempted to clarify whether over-secretion of glucocorticoids in the serum caused by increased hypothalamus-pituitary-adrenal activity induces oxidative stress in the rat brain, and how the stress causes the emergence of cognitive deficits. When rats were subcutaneously injected with corticosterone, lipid hydroperoxides and protein carbonyls increased markedly in the hippocampus in association with a decrease in activity of antioxidative enzymes, such as superoxide dismutase, catalase and glutathione peroxidase. These results suggest that high-level corticosterone in the serum induces reactive oxygen species (ROS), leading to oxidative damage in the hippocampus. After administration of corticosterone to rats, glucose and superoxide levels in the serum increased markedly. Furthermore, pyramidal cell apoptosis was observed to accompany the loss of glucocorticoid receptors at the cornus ammonis 1 region of the hippocampus. Rats injected with corticosterone showed marked deficits in memory function. The present results imply that ROS generated from the glycation reaction of increased glucose levels caused by gluconeogenesis activation through glucocorticoid with proteins in the serum attack the hippocampus to induce neurodegeneration, resulting in cognitive deficits in rats

Online Estimation of Self-Body Deflection With Various Sensor Data Based on Directional Statistics

In this paper, we propose a method for online estimation of the robot's posture. Our method uses von Mises and Bingham distributions as probability distributions of joint angles and 3D orientation, which are used in directional statistics. We constructed a particle filter using these distributions and configured a system to estimate the robot's posture from various sensor information (e.g., joint encoders, IMU sensors, and cameras). Furthermore, unlike tangent space approximations, these distributions can handle global features and represent sensor characteristics as observation noises. As an application, we show that the yaw drift of a 6-axis IMU sensor can be represented probabilistically to prevent adverse effects on attitude estimation. For the estimation, we used an approximate model that assumes the actual robot posture can be reproduced by correcting the joint angles of a rigid body model. In the experiment part, we tested the estimator's effectiveness by examining that the joint angles generated with the approximate model can be estimated using the link pose of the same model. We then applied the estimator to the actual robot and confirmed that the gripper position could be estimated, thereby verifying the validity of the approximate model in our situation.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

The History of the University of Tokyo May Festival (Gogatsusai) : Its Origins and Evolution During the Tokyo Imperial University Years

History of campus festivals is an important topic of historial studies on the university. The purpose of this study is to describe the history of the campus festival of the University of Tokyo, or Gogatsusai (May Festival), based on materials such as programs and articles of the Teikoku Daigaku Shimbun (Imperial University Newspaper). This event, which was begun as the Dai-enyukai (Garden Party) in 1923, has changed to the present Gogatsusai after evolution including two interruptions

Cerebrovascular Disease; A Leading Cause of Epilepsy

Various types of cerebrovascular diseases can result in epilepsy in any age, especially in the elderly. Besides well-known cause of epilepsy as large cerebral infarction involving cerebral cortex and intracerebral hemorrhage, there are growing evidences of roles of subcortical infarction, chronic subdural hematoma, and superficial siderosis of the central nervous system in the pathogenesis of epilepsy. We review here the epidemiology and possible predictors of epilepsy in each type of cerebrovascular lesions and summarize the characteristics of semiology and electroencephalography findings in order to take early treatment strategy. Additionally, relevance of acute-symptomatic seizures and status epilepticus to epilepsy is discussed

A Suzaku Observation of the Low-Ionization Fe-Line Emission from RCW 86

The newly operational X-ray satellite Suzaku observed the southwestern quadrant of the supernova remnant (SNR) RCW 86 in February 2006 to study the nature of the 6.4 keV emission line first detected with the Advanced Satellite for Cosmology and Astronomy (ASCA). The new data confirm the existence of the line, localizing it for the first time; most of the line emission is adjacent and interior to the forward shock and not at the locus of the continuum hard emission. We also report the first detection of a 7.1 keV line that we interpret as the K-beta emission from low-ionization iron. The Fe-K line features are consistent with a non-equilibrium plasma of Fe-rich ejecta with n_{e}t <~ 10^9 cm^-3 s and kT_{e} ~ 5 keV. This combination of low n_{e}t and high kT_{e} suggests collisionless electron heating in an SNR shock. The Fe K-alpha line shows evidence for intrinsic broadening, with a width of 47 (34--59) eV (99% error region). The difference of the spatial distributions of the hard continuum above 3 keV and the Fe-K line emission support a synchrotron origin for the hard continuum.Comment: 6 pages with 6 figures. Accepted for PASJ Suzaku Special Issue (vo. 58, sp.1