Acute Gravitational Stress Selectively Impairs Dynamic Cerebrovascular Reactivity in the Anterior Circulation Independent of Changes to the Central Respiratory Chemoreflex

Cerebrovascular reactivity (CVR) to changes in the partial pressure of arterial carbon dioxide (PaCO(2)) is an important mechanism that maintains CO(2) or pH homeostasis in the brain. To what extent this is influenced by gravitational stress and corresponding implications for the regulation of cerebral blood flow (CBF) remain unclear. The present study examined the onset responses of pulmonary ventilation (V̇(E)) and anterior middle (MCA) and posterior (PCA) cerebral artery mean blood velocity (V(mean)) responses to acute hypercapnia (5% CO(2)) to infer dynamic changes in the central respiratory chemoreflex and cerebrovascular reactivity (CVR), in supine and 50° head-up tilt (HUT) positions. Each onset response was evaluated using a single-exponential regression model consisting of the response time latency [CO(2)-response delay (t(0))] and time constant (τ). Onset response of V̇(E) and PCA V(mean) to changes in CO(2) was unchanged during 50° HUT compared with supine (τ: V̇(E), p = 0.707; PCA V(mean), p = 0.071 vs. supine) but the MCA V(mean) onset response was faster during supine than during 50° HUT (τ: p = 0.003 vs. supine). These data indicate that gravitational stress selectively impaired dynamic CVR in the anterior cerebral circulation, whereas the posterior circulation was preserved, independent of any changes to the central respiratory chemoreflex. Collectively, our findings highlight the regional heterogeneity underlying CBF regulation that may have translational implications for the microgravity (and hypercapnia) associated with deep-space flight notwithstanding terrestrial orthostatic diseases that have been linked to accelerated cognitive decline and neurodegeneration

２０世紀初頭のイギリスにおける移民政策の形成と展開 : 福祉国家・戦争国家における「他者」としての外国人

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 小野塚 知二, 東京大学教授 大澤 眞理, 東京大学教授 馬場 哲, 東京大学准教授 石原 俊時, 千葉大学准教授 中村 千尋University of Tokyo(東京大学

The study of Collaborative Learning in Physical Education with the Use of Tablet Devices : With a special focus on team conferences in volleyball

本研究は，バレーボールの授業において，協働的な学びを促進する手立てとして，タブレット端末を使用して得たゲーム記録を，ふり返り場面でどのように活用したかを探るとともに，チーム会議での話し合いの実態を明らかにすることを目的とした。チーム会議の発話記録を分析した結果，タブレット端末に記録された返球率，返球数のデータは，ふり返りの視点となり，話し合いのきっかけになっていた。また，チーム会議は協働的な学びの場となり，チームメイトを認める発話と問いかける発話が協働的な学びの質を高めることがわかった。The present study aims to find out how the students made use of game records in their tablet devices when reflecting on their games and what was going on in their discussion. By analyzing their utterances in their team conferences, it is revealed that the numbers and ratios of the returns of the ball recorded in their tablet devices were utilized as the viewpoints of their discussion and they facilitate their discussion. It is also thought that team conferences give the students the opportunity to learn collaboratively and that the utterances which accept their teammates and the ones which ask their teammates questions enrich collaborative learning

The Usefulness of "Hybrid Unit" Goal-based Learning on Physical Education: Focusing on the practice of tag rugby, handball, and basketball in junior high schools

The purpose of this study was to address a motor learning program consisting of "hybrid units" and to clarify the usefulness of the learning sequence and arrangement by analyzing the common movement patterns among various athletic activities . Then, we conducted empirical lessons of two units: tag rugby-handball and handball-basketball. Results showed that " forming a line in a defense and "passing effectively in an attack" are common ways of moving. In addition, it was found that both defensive and offensive movements became progressively more complex and could be studied in a developmental sequence

Does respiratory drive modify the cerebral vascular response to changes in end‐tidal carbon dioxide?

What is the central question of this study? An interaction exists between the regulatory systems of respiration and cerebral blood flow (CBF), because of the same mediator (carbon dioxide, CO ) for both physiological systems. The present study examined whether the traditional method for determining cerebrovascular reactivity to CO (cerebrovascular reactivity; CVR) is modified by changes in respiration. What is the main finding and its importance? CVR was modified by voluntary changes in respiration during hypercapnia. This finding suggests that an alteration in the respiratory system may under- or over-estimate CVR determined by traditional methods in healthy adults.The cerebral vasculature is sensitive to changes in the arterial partial pressure of carbon dioxide (CO ). This physiological mechanism has been well established as a cerebrovascular reactivity to CO (CVR). However, arterial CO may not be an independent variable in the traditional method to assess CVR since the cerebral blood flow (CBF) response is partly affected by the activation of respiratory drive or higher centers in the brain. We hypothesized that CVR is modified by changes in respiration. To test our hypothesis, in the present study, ten young healthy subjects performed hyper- or hypo-ventilation to change end-tidal CO (P CO ) under different concentrations of CO gas inhalation (0, 2.0, 3.5%). We measured middle cerebral artery mean blood flow velocity (MCAVm) by transcranial Doppler to identify the CBF response to change in P CO during each condition. At each F CO condition, P CO was significantly altered by changes in ventilation, and MCA Vm changed accordingly. However, the relationship between changes in MCV Vm and P CO as a response curve of CVR was reset upwards and downwards by hypo- and hyper-ventilation, respectively, compared with CVR during normal-ventilation. The findings of the present study may provide the possibility that an alteration in respiration under- or over-estimates CVR determined by the traditional methods

A Study of the Effect of the Action Research Type Training in a Master's Course Stage : focusing on the alteration trend of knowledge and teaching skills in the health and physical education trainee

The aim of this study was to clarify the effect of the action research type training in a master's course stage, especially focusing on two knowledge: "teacher's practical knowledge" and "teacher knowledge about pedagogy". As a result, two points were made clear. 1. Throughout the action research type training, simplex knowledge about "teacher's practical knowledge" was greatly seen in the graduate students in a master's course, similar to the prior research. Plus, "Teacher knowledge about pedagogy" was also seen in the action research type training. 2. Throughout the action research type training, graduate students in a master's course changed its' multiple "teacher's practical knowledge" and "teacher knowledge about pedagogy" by receiving mentoring from a faculty member, supervisor, and mentor.本研究の成果の一部は,平成24～26年度科学研究費補助金(若手研究B)「実践的指導力」を育成する学部・大学院一貫の体育教員養カリキュラムの開発と実践(課題番号24700624)の補助によ

Effects of Green Tea Fractions on Oxygen-Induced Retinal Neovascularization in the Neonatal Rat

This study aimed to investigate the preventive effects of green tea fractions (GTFs) on rat model of oxygen-induced retinopathy (OIR). Neonatal Sprague-Dawley rats were exposed to daily cycles of 80% oxygen (20.5 h), ambient air (0.5 h), and progressive return to 80% oxygen (3 h) until postnatal day 12 (P12), then the rats were placed in ambient air until P18. The green tea was fractionated by DM-A50, DM-W, M-B, and M-W. The rats were treated once daily from P6 to P17 by gastric gavage of GTFs (0.05 or 0.01 g/ml) or distilled water (DW) at 50 µl/10 g body weight. On P18, the rats were sacrificed and the retinal samples were collected. The retinal neovascularization (NV) was scored and avascular areas (AVAs) were measured as a % of total retinal area (%AVAs) in ADPase stained retinas. The NV scores in 0.01 g/ml M-W were significantly lower than those in DW. The %AVAs in 0.05 g/ml DM-A50 and in 0.05 g/ml and 0.01 g/ml M-W were significantly lower than those in DW. There were less catechins, and less caffeine in M-W fraction compared with other GTFs, suggesting components of green tea except for catechins and caffeine might suppress the neovascularization in rat model of OIR