Term Structure of Interest Rates under Recursive Preferences in Continuous Time ( Revised in February 2008, subsequently published in "Asia-Pacific Financial Markets", Vol.15-3,4, 273-305. )

This paper proposes a testable continuous-time term-structure model with recursive utility to investigate structural relationships between the real economy and the term structure of real and nominal interest rates. In a representative-agent model with recursive utility and mean-reverting expectations on real output growth and inflation, this paper shows that, if (1) real short-term interest rates are high during economic booms and (2) the agent is comparatively risk-averse (less risk-averse) relative to time-separable utility, then a real yield curve slopes down (slopes up, respectively). Additionally, for the comparatively risk-averse agent, if (3) expected inflation is negatively correlated with the real output and its expected growth, then a nominal yield curve can slope up, regardless of the slope of the real yield curve.

Somatosensory Evoked Potentials in Cerebral Infarction Model Rats Induced by Microsphere Injection to Cerebral Artery

Microspheres, monodisperse polystyrene beads, are used for the study of cerebral infarction by injection into the cerebral artery. Cerebral infarction model rats were made by injecting 2,600 microspheres into the right internal carotid artery in this study. Motor ability was assessed by the rotarod test in which cling duration on the accelerating rotating rod was measured. Significant decrease in the motor ability was recognized on 3 and 15 days after the embolization compared with before surgery (p<0.05). However, sham-operated rats did not show significant change of motor ability. Each rat was reanaesthetized 15 days after surgery, and somatosensory evoked potentials (SEPs) induced by stimulation of the sciatic nerve of the contralateral hind limb were averaged. Latencies of N_1 and N_2 waves in SEPs were compared between sham-operated rats and embolized rats 15 days after surgery. No significant differences in N_1 and N_2 latencies were recognized between the two groups. These results suggest that motor ability was impaired at chronic periods of the embolization, while SEPs recovered, although latencies of N_1 and N_2 in SEPs were reported to increase at acute periods in embolized rats

Changes in the lactate threshold during treadmill exercise after microsphere-induced infarction in rats.

The aim of this study was to clarify changes in the lactate threshold (LT) in the acute period after cerebral infarction. Cerebral infarction was induced by the injection of microspheres (MS) into the right internal carotid artery. To estimate the degree of neurologic deficit caused by surgery, the behaviors of all rats were evaluated in terms of typical symptoms of stroke in rats. The rotarod test was used to evaluate equilibrium function. Rats were forced to perform stepwise treadmill exercises, and serial changes in blood lactate concentration were measured for determination of the LT. The average treadmill speed at the LT and the rotarod test performance in MS rats was significantly lower than those in sham-operated rats on postsurgery day 2. However, although neurologic deficits disappeared on postsurgery day 7 in MS rats, LT level and rotarod test performance were significantly lower than in sham-operated rats. These results suggest that the decrease in LT in the acute period after cerebral infarction might be induced by impaired equilibrium function. Other possibilities are discussed as well

Development of a Novel Antibacterial Medicine that Targets a Characteristic Lipid of the Cell Membranes of <em>Helicobacter pylori</em>

Helicobacter pylori is one of the most prevalent causes of gastritis. This pathogen colonizes for many years human stomach and asymptomatically leads the persons to chronic gastritis. The eradication of H. pylori from human stomach is, therefore, important in order to prevent the digestive diseases including peptic ulcers and gastric cancer that develop via chronic atrophic gastritis. Wide-spectrum antibiotics such as amoxicillin and metronidazole are used for the treatment for H. pylori infectious diseases. However, the H. pylori strains resistant to these antibiotics are increasing year by year around the world. On this basis, we need urgently to develop the antibacterial medicines that act on H. pylori with a novel mechanism. Recent studies by our group have demonstrated that H. pylori shows susceptibility to the bactericidal action of indene compounds derived from decomposition of vitamin D. The bactericidal action of indene compounds is selective not against commonplace bacteria but against H. pylori. The indene compounds turned out to target the H. pylori’s phosphatidylethanolamine that retains a myristic acid as the saturated fatty acid side chain. These findings will contribute to the development of new antibacterial medicines specialized to the treatment for H. pylori infectious diseases

Point Cloud-based Proactive Link Quality Prediction for Millimeter-wave Communications

This study demonstrates the feasibility of point cloud-based proactive link quality prediction for millimeter-wave (mmWave) communications. Previous studies have proposed machine learning-based methods to predict received signal strength for future time periods using time series of depth images to mitigate the line-of-sight (LOS) path blockage by pedestrians in mmWave communication. However, these image-based methods have limited applicability due to privacy concerns as camera images may contain sensitive information. This study proposes a point cloud-based method for mmWave link quality prediction and demonstrates its feasibility through experiments. Point clouds represent three-dimensional (3D) spaces as a set of points and are sparser and less likely to contain sensitive information than camera images. Additionally, point clouds provide 3D position and motion information, which is necessary for understanding the radio propagation environment involving pedestrians. This study designs the mmWave link quality prediction method and conducts realistic indoor experiments, where the link quality fluctuates significantly due to human blockage, using commercially available IEEE 802.11ad-based 60 GHz wireless LAN devices and Kinect v2 RGB-D camera and Velodyne VLP-16 light detection and ranging (LiDAR) for point cloud acquisition. The experimental results showed that our proposed method can predict future large attenuation of mmWave received signal strength and throughput induced by the LOS path blockage by pedestrians with comparable or superior accuracy to image-based prediction methods. Hence, our point cloud-based method can serve as a viable alternative to image-based methods.Comment: Submitted to IEEE Transactions on Machine Learning in Communications and Networkin

クロサンショウウオにおける卵サイズの地理的変異に関する研究

取得学位：博士(理学)，学位授与番号：博甲第139号，学位授与年月日：平成7年3月25日,学位授与年：199