Application of a nonlinear time series analysis ： bimanual coordination in a balance sport slackline

本稿では、筆者が２０１６年６月に参加した米国心理学会のAdvanced Training Institutes のNonlinear Methods for Psychological Science というデータ解析に関する研修の報告と、そこで得られた知識、技術を筆者自身の研究に応用した事例について報告する。具体的には、非線形時系列解析手法のうち、本稿では、システムのダイナミクスにみられる“再帰性”のパターンに基づく分析（再帰定量化分析）を取り上げ、スラックラインという綱渡り競技をしている際の両手の協調性の定量化に応用した事例を紹介する。その結果、本手法を応用することで、スラックラインの身体技能のレベルを定量的に評価できる可能性が示唆された。本研究の知見は、スラックラインの身体技能、コツの解明につながるため、スラックラインの指導や実践の現場へのフィードバックが可能であり、より安全で効果的な訓練方法の提案につながると考えられる。また、本手法は、経済学・社会科学分野のデータにも応用されており、今後、様々なデータへの応用が期待される。研究ノート2016年度研究支

VEGF-A induces tumor and sentinel lymph node lymphangiogenesis and promotes lymphatic metastasis

The mechanisms of tumor metastasis to the sentinel lymph nodes are poorly understood. Vascular endothelial growth factor (VEGF)-A plays a principle role in tumor progression and angiogenesis; however, its role in tumor-associated lymphangiogenesis and lymphatic metastasis has remained unclear. We created transgenic mice that overexpress VEGF-A and green fluorescent protein specifically in the skin, and subjected them to a standard chemically-induced skin carcinogenesis regimen. We found that VEGF-A not only strongly promotes multistep skin carcinogenesis, but also induces active proliferation of VEGF receptor-2–expressing tumor-associated lymphatic vessels as well as tumor metastasis to the sentinel and distant lymph nodes. The lymphangiogenic activity of VEGF-A–expressing tumor cells was maintained within metastasis-containing lymph nodes. The most surprising finding of our study was that even before metastasizing, VEGF-A–overexpressing primary tumors induced sentinel lymph node lymphangiogenesis. This suggests that primary tumors might begin preparing their future metastatic site by producing lymphangiogenic factors that mediate their efficient transport to sentinel lymph nodes. This newly identified mechanism of inducing lymph node lymphangiogenesis likely contributes to tumor metastasis, and therefore, represents a new therapeutic target for advanced cancer and/or for the prevention of metastasis

Balance Training With a Vibrotactile Biofeedback System Affects the Dynamical Structure of the Center of Pressure Trajectories in Chronic Stroke Patients

Haptic-based vibrotactile biofeedback (BF) is a promising technique to improve rehabilitation of balance in stroke patients. However, the extent to which BF training changes temporal structure of the center of pressure (CoP) trajectories remains unknown. This study aimed to investigate the effect of vibrotactile BF training on the temporal structure of CoP during quiet stance in chronic stroke patients using detrended fluctuation analysis (DFA). Nine chronic stroke patients (age; 81.56 ± 44 months post-stroke) received a balance training regimen using a vibrotactile BF system twice a week over 4 weeks. A Wii Balance board was used to record five 30 s trials of quiet stance pre- and post-training at 50 Hz. DFA revealed presence of two linear scaling regions in CoP indicating presence of fast- and slow-scale fluctuations. Averaged across all trials, fast-scale fluctuations showed persistent dynamics (α = 1.05 ± 0.08 for ML and α = 0.99 ± 0.17 for AP) and slow-scale fluctuations were anti-persistent (α = 0.35 ± 0.05 for ML and α = 0.32 ± 0.05 for AP). The slow-scale dynamics of ML CoP in stroke patients decreased from pre-training to post-BF training (α = 0.40 ± 0.13 vs. 0.31 ± 0.09). These results suggest that the vibrotactile BF training affects postural control strategy used by chronic stroke patients in the ML direction. Results of the DFA are further discussed in the context of balance training using vibrotactile BF and interpreted from the perspective of intermittent control of upright stance

Multiple emission lines of Hα\alpha emitters at z∼2.3z \sim 2.3 from the broad and medium-band photometry in the ZFOURGE Survey

We present a multiple emission lines study of $\sim$1300 H$\alpha$ emitters (HAEs) at $z \sim 2.3$ in the ZFOURGE survey. In contrast to the traditional spectroscopic method, our sample is selected based on the flux excess in the ZFOURGE-$K_s$ broad-band data relative to the best-fit stellar continuum. Using the same method, we also extract the strong diagnostic emission lines for these individual HAEs: [OIII]$\lambda\lambda4959,5007$, [OII]$\lambda\lambda3726,3729$. Our measurements exhibit good consistency with those obtained from spectroscopic surveys. We investigate the relationship between the equivalent widths (EWs) of these emission lines and various galaxy properties, including stellar mass, stellar age, star formation rate (SFR), specific SFR (sSFR), ionization states (O32). We have identified a discrepancy between between HAEs at $z\sim2.3$ and typical local star-forming galaxy observed in the SDSS, suggesting the evolution of lower gas-phase metallicity ($Z$) and higher ionization parameters ($U$) with redshift. Notably, we have observed a significant number of low-mass HAEs exhibiting exceptionally high $EW_{\mathrm{[OIII]}}$. Their galaxy properties are comparable to those of extreme objects, such as extreme O3 emitters (O3Es) and Ly$\alpha$ emitters (LAEs) at $z\simeq2-3$. Considering that these characteristics may indicate potential strong Lyman continuum (LyC) leakage, higher redshift anaglogs of the low-mass HAEs could be significant contributors to the cosmic reionization. Further investigations on this particular population are required to gain a clearer understanding of galaxy evolution and cosmic reionization.Comment: 24 pages, 13 figures, submitted to Ap

A preliminary study on application of a balance sport slackline to FYS

本稿では、バランス・スポーツ“スラックライン”を初年次教育の題材として用いた事例的研究について報告する。スラックラインとは、綱渡りを競技として発展させたものであり、現在、スポーツやレジャー、身体教育や健康促進、リハビリテーションの一環としてなど、様々な分野・用途で応用されている。本研究では、誰でも気軽に楽しめ、省スペースで実施でき、コミュニケーションのツールともなるスラックラインを、初年次教育における仮説検証学習の題材として応用し、学生らが自らの身体を使って体験的に学ぶことで、学習が促進されるかどうかについて検討した。授業後のアンケートの結果、スラックラインを取り入れた授業によって、自身や他者についての理解や気づきが促され、コミュニケーションが活性化し、楽しい学習の場が提供できたことが示唆された。これらの結果は、スラックラインが初年次教育の題材として有効である可能性を部分的に示している。論