Did My Hand Move in a Mirror? Body Ownership Induced by the Mirror Hand Illusion

Although the illusion that the mirror image of a hand or limb could be recognized as a part of one’s body behind the mirror, the effect of adding tactile stimulation to this illusion remains unknown. We, therefore, examined how the timing of tactile stimulation affects the induction of body ownership on the mirror image. Twenty-one healthy, right-handed participants (mean age = 23.0 ± 1.0 years, no medical history of neurological and/or psychiatric disorders) were enrolled and a crossover design was adopted in this study. Participants’ right and left hands were placed on the front and back sides of the mirror, respectively, then they were asked to keep looking at their right hand in the mirror. All participants experienced two experiments; one was with tactile stimulation that was synchronized with the movement of a mirror image (synchronous condition), and the other one was with tactile stimulation that was not synchronized (asynchronous condition). The qualitative degree of body ownership for the mirrored hand was evaluated by a questionnaire. Proprioceptive drift (PD), an illusory shift of the felt position of the real hand toward the mirrored hand was used for quantitative evaluation of body ownership and measured at “baseline,” “immediately after stimulation,” “2 min after stimulation,” and “4 min after stimulation.” The results of the questionnaire revealed that some items of body ownership rating were higher in the synchronous condition than in the asynchronous condition (p < 0.05). We found that PD occurred from immediately after to 4 min after stimulation in both conditions (p < 0.01) and there was no difference in the results between the conditions. From the dissociation of these results, we interpreted that body ownership could be elicited by different mechanisms depending on the task demand. Our results may contribute to the understanding of the multisensory integration mechanism of visual and tactile stimulation during mirror illusion induction

Histological Study of the Left Atrial Wall: A Consideration of the Compound Myocardial Architecture and Potential Durability with Respect to Catheter Ablation in Pulmonary Vein Isolation Procedures

Pulmonary vein isolation using radiofrequency energy is performed extensively to treat symptomatic, drug-refractory atrial fibrillation. However, anatomical knowledge of the left atrial wall surrounding the pulmonary vein (PV) openings is insufficient to create an ablation line. Using autopsy hearts from 23 individuals (median age of 63 years), we studied the histological nature of anatomical obstacles or related isthmuses near the PV openings. None of the individuals had a history of tachyarrhythmia or other major cardiac abnormalities. After macroscopic measurement of the minimum width of each isthmus, the following areas were excised and histologically prepared: atrial roof-mitral valve annulus (MVA), left superior pulmonary vein (LSPV) -left atrial appendage (LAA), LAA-MVA, left inferior pulmonary vein (LIPV) -MVA, right superior pulmonary vein (RSPV) -fossa ovalis (FO), right inferior pulmonary vein (RIPV) -FO, and FO-MVA. Within the obstacles near the PV openings, the LSPV-LAA isthmus was found to be the narrowest, whereas the LIPV-MVA was the widest and thickest isthmus. Histological complexity of each isthmus was determined, and the compound architecture of the myocardium was revealed. The further presence of a variety of nerve endings as well as myocardial blood supply enhanced the tissue diversity. Such an insight into the diversity of myocardial architecture or histological complexity in each isthmus might be helpful in creating a reliable ablation line in pulmonary vein isolation procedures

Overall Feature of CP dependence for Neutrino Oscillation Probability in Arbitrary Matter Profile

We study the CP dependence of neutrino oscillation probability for all channels in arbitrary matter profile within three generations. We show that an oscillation probability for \nu_e \to \nu_\mu can be written in the form P(\nu_e \to \nu_\mu) =A_{e\mu} cos \delta + B_{e\mu} sin \delta + C_{e\mu} without any approximation using the CP phase \delta. This result holds not only in constant matter but also in arbitrary matter. Another probability for \nu_\mu \to \nu_\tau can be written in the form P(\nu_\mu \to \nu_\tau)= A_{\mu\tau} cos \delta + B_{\mu\tau} sin \delta + C_{\mu\tau} + D_{\mu\tau} cos 2\delta + E_{\mu\tau} sin 2\delta. The term which is proportional to sin 2\delta disappear, namely E_{\mu\tau}=0, in symmetric matter. It means that the probability reduces to the same form as in constant matter. As for other channels, probabilities in arbitrary matter are at most the quadratic polynomials of sin \delta and cos \delta as in the above two channels. In symmetric matter, the oscillation probability for each channel reduces to the same form with respect to \delta as that in constant matter.Comment: 11 pages, no figures, LaTeX2e, a few misprints have been correcte

視野左方偏倚が線分二等分試験に及ぼす影響 : Head Mounted Displayを用いた若年健常者に対する検討

Objective: The purpose of this study was to verify the effect on spatial perception in healthy young subjects of an unconscious leftward optical shift created by a head-mounted display (HMD) with an offset camera. Methods: We recruited 40 healthy right-handed adults who were divided into four groups according to the hand used in the tests and the visual direction displayed by the HMD (centered or 10° left). Each of the four groups (n = 10) undertook line bisection tasks across four combinations of variables: using a finger/stick or a mouse to point at a touch panel located 60 or 120 cm away from the subject. Results: According to the results, regardless of the hand used, when the index finger or a stick was used (reaching condition), the line bisection point was displaced significantly to the left of the center. Additionally, a major left-displacement trend was observed in the short-distance reaching task, which did not require the use of a stick. In contrast, the long-distance task required a stick to be used, and the left displacements were all smaller than those for the short-distance tasks that used the index finger. Conclusion: This finding may be explained by the subjects having sufficient experience coordinating hand and eye movements in the condition where they used their dominant hand and reached with their own arms without using a stick.東京都立大学学位論文甲第1160号　副論

Enhancement of CP Violating terms for Neutrino Oscillation in Earth Matter

We investigate the $\nu_e \to \nu_{\mu}$ oscillation in the framework of three generations when neutrinos pass through the earth. The oscillation probability is represented by the form, $P(\nu_e \to \nu_\mu)=A\cos \delta+B\sin \delta+C$ in arbitrary matter profile by using the leptonic CP phase $\delta$. We compare our approximate formula in the previous paper with the formula which includes second order terms of $\alpha=\Delta m_{21}^2/\Delta m_{31}^2$ and $s_{13}=\sin \theta_{13}$. Non-perturbative effects of $\alpha$ and $s_{13}$ can be taken into account in our formula and the precision of the formula is rather improved around the MSW resonance region. Furthermore, we compare the earth matter effect of $A$ and $B$ with that of $C$ studied by other authors. We show that the magnitude of $A$ and $B$ can reach a few ten % of $C$ around the main three peaks of $C$ in the region $E>1$ GeV by numerical calculation. We give the qualitative understanding of this result by using our approximate formula. The mantle-core effect, which is different from the usual MSW effect, appears not only in $C$ but also in $A$ and $B$, although the effect is weakened.Comment: 16 pages, 5 figure

Proposal of a Simple Method to Estimate Neutrino Oscillation Probability and CP Violation in Matter

We study neutrino oscillation within the framework of three generations in matter. We propose a simple method to approximate the coefficients A, B and C which do not depend on the CP phase \delta in the oscillation probability P(\nu_e \to \nu_{\mu})=A\cos \delta + B\sin \delta +C. An advantage of our method is that an approximate formula of the coefficients A, B and C in arbitrary matter {\it without the usual first order perturbative calculations} of the small parameter \Delta m_{21}^2/\Delta m_{31}^2 or \sin \theta_{13} can be derived. Furthermore we show that all the approximate formulas for low, intermediate and high energy regions given by other authors in constant matter can be easily derived from our formula. It means that our formula is applicable over a wide energy region.Comment: 15 pages, 9 figures, accepted version in PL

Influence of Heat-affected Sea Coal on Green Sand

The characteristic of green sand changes as it is heated by pouring. Then, after experimental repeated pouring, the green sand composition, and its properties were measured, and the penetration defect caused in a test casting was detected. As a result, it became evident that the sea coal in green sand changed the condition by the heat influence. That is, the sea coal powder changed to adhere to sand surface as the total clay removal. After heating, the oolitics increased, the specimen density increased, and the scabbing time decreased. The penetration defect became difficult to occur when volatile matter in sea coal was more and ash in sea coal was less

Control of Green Sand by Oolitics

In the control of green sand by oolitics, it is necessary to quantify oolitics accurately. For this, the quantity of quartz in green sand is quantified first, then oolitics is quantified after calibrating the base sand which is silica sand for calibration and for core used in green sand. However, since certain kinds of base sand are used in recent green sand, calibration and consequently the quantification of oolitics are not possible. The authors therefore developed a new method for quantifing oolitics. Feldspar and quartz are analyzed quantitavely at the same time by X-ray diffractometric analysis by reason of which base sand is quantitatively calibrated for the purpose of calibrating feldspar in silica sand. Quartz is calculated from the integrated intensity of the diffraction peak 20.9°and feldspar is calculated from the sum of each diffraction peak from 26.9°to 28.0°. The oolitics quantity in green sand can be calculated accurately by this method. The average value of oolitics in 67 different kinds of system sand was 6.9 mass% and the standard deflection was 3.7 mass%. The accurate quantification of oolitics enables control of green sand

Statistical Analysis of Green Sand Properties

As a result of Analysis of green sand properties on 100 lines of system sand in 1985 and 1998 respectively, it showed a tendency that green sand, analyzed in 1998, had lower compactability and higher strength compared with those in 1985. Also lower deviation was recognized. So it can be said that green sands in 1998 have changed to higher quality one with better flowability, while they are almost same properties among them. This change corresponds to an improvement of recent molding machine which have higher productivity and better dimensional precision. Green sand properties in 1998 were assorted into each type of molding machine. As a result, it has experienced that hey have such properties as higher strength in case of shock wave type of molding machine. Then, green sand control indexes for each molding machine have been obtained. The relationship between green sand properties and additional volume of green materials, used volume of core sand, and sand-metal ratio were checked. As a result, additional volume of each green materials such as bentonite, starch and sea coal has been able to be calculated by remained volume of each materials, used volume of new sand and core sand, and sand-metal ratio. Then, objective standard of judgment for additional volume has been clear by comparing calculated and measured volume

Mast Cell Infiltration is Associated with Myelofibrosis and Angiogenesis in Myelodysplastic Syndromes

Myelodysplastic syndromes are a heterogeneous group of clonal hematopoietic stem cell disorders characterized by persistent peripheral cytopenia with morphological and functional abnormalities of hematopoietic cells. Mast cells infiltrate into or around tumor tissues and play a role in remodeling of the stromal microenvironment, contributing to tumor progression. Increased mast cell numbers are associated with fibrosis, angiogenesis and a poor prognosis in human carcinomas. The aim of this study was to determine whether mast cell infiltration contributes to myelofibrosis or angiogenesis in myelodysplastic syndromes. We evaluated the correlation between mast cell density and the extent of myelofibrosis and angiogenesis in myelodysplastic syndromes. Fifty bone marrow biopsies taken from patients with a diagnosis of myelodysplastic syndromes were examined. Grading of myelofibrosis was evaluated by silver impregnation staining. Mast cell density and microvessel density were evaluated by immunohistochemistry. Human mast cells have been divided into two phenotypes. We designated a tryptase-positive mast cell as MCT and a chymase-positive mast cell as MCTC. Microvessels were identified by CD34-positive endothelial cells. Microvessel density and the extent of myelofibrosis were significantly greater in patients with high MCT and MCTC density compared to those with low MC density. Based on this, we suggest that the presence of high mast cell numbers is associated with myelofibrosis and angiogenesis in myelodysplastic syndromes