フォロワー企業の外部人材活用による学習効果に関する実証分析Empirical analysis of the effect of learning by hiring by follower firm

学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 渡部 俊也, 東京大学教授 元橋 一之, 東京大学教授 坂田 一郎, 東京大学教授 影山 和郎, 東北大学教授 福嶋 路University of Tokyo(東京大学

Validity of the frame subtraction method in dynamic postural stability

Background The movement of targeted subjects can be calculated using the frame subtraction method. However, the validity of this evaluation method of dynamic postural stability has not been clarified yet. This study aimed to verify the validity of the evaluation method for jump landing using the frame subtraction score based on the ground reaction force (GRF). Methods Twenty subjects performed single-leg jump landing, and their dynamic postural stability index (DPSI), medial-lateral stability index (MLSI), anterior-posterior stability index, and vertical stability index (VSI) were calculated from the GRF. Simultaneously, motion images were captured using digital video cameras in the sagittal and frontal planes. After the motion images were analyzed using the frame subtraction method, the frame subtraction scores in the frontal, sagittal, and combined planes were calculated. To confirm its validity, the relationship between the frame subtraction scores and GRF parameters was investigated using Pearson's correlation analysis. Results The frame subtraction scores in the frontal and combined planes were significantly correlated with the DPSI, MLSI, and VSI (r = 0.46-0.75, P < 0.05). Conclusions Therefore, the frame subtraction method could be applied to the evaluation of dynamic postural stability. Markerless systems are deemed useful in clinical practice

Surgical resection of mixed neuroendocrine-non-neuroendocrine neoplasm in the biliary system: a report of two cases

Background Mixed neuroendocrine-non-neuroendocrine neoplasm (MINEN) is a rare disease and there is scarce literature on its diagnosis, treatment, and prognosis. We encountered two unusual cases of MINEN in the biliary tract, one in the ampulla of Vater and the other in the distal bile duct. In this report, we describe the clinical course of these two cases in detail. Case presentation Case 1: A 69-year-old woman presented with a chief complaint of epigastric pain. When endoscopic sphincterotomy and retrograde biliary drainage were performed for gallstone pancreatitis, an ulcerated lesion was found in the ampulla of the Vater. Based on the biopsy results, the lesion was diagnosed as the ampulla of Vater carcinoma and subtotal stomach-preserving pancreatoduodenectomy (SSPPD) was performed. Postoperative histopathological examination revealed the coexistence of adenocarcinoma and neuroendocrine carcinoma components, consistent with the diagnosis of MINEN. In addition, lymph node metastasis was found on the dorsal side of the pancreas and the metastatic component was adenocarcinoma. Adjuvant chemotherapy with etoposide and cisplatin was administered for 6 months, and presently the patient is alive without recurrence 64 months after surgery. Case 2: A 79-year-old man presented with a chief complaint of anorexia. Cholangiography showed severe stenosis of the distal bile duct. A biopsy was conducted from the stenotic lesion and it revealed the lesion to be adenocarcinoma. A diagnosis of distal bile duct carcinoma was made, and SSPPD was performed. Histopathological examination revealed the coexistence of adenocarcinoma and neuroendocrine carcinoma components, and the tumor was confirmed as MINEN of the distal bile duct. No adjuvant chemotherapy was administered due to the poor performance status. 7 months later, the patient was found to have a liver metastasis. Conclusion We experienced two valuable cases of biliary MINEN. To identify better treatments, it is important to consider the diversity of individual cases and to continue sharing a variety of cases with different presentations

C9orf72-derived arginine-rich poly-dipeptides impede phase modifiers

Nuclear import receptors (NIRs) not only transport RNA-binding proteins (RBPs) but also modify phase transitions of RBPs by recognizing nuclear localization signals (NLSs). Toxic arginine-rich poly-dipeptides from C9orf72 interact with NIRs and cause nucleocytoplasmic transport deficit. However, the molecular basis for the toxicity of arginine-rich poly-dipeptides toward NIRs function as phase modifiers of RBPs remains unidentified. Here we show that arginine-rich poly-dipeptides impede the ability of NIRs to modify phase transitions of RBPs. Isothermal titration calorimetry and size-exclusion chromatography revealed that proline:arginine (PR) poly-dipeptides tightly bind karyopherin-β2 (Kapβ2) at 1:1 ratio. The nuclear magnetic resonances of Kapβ2 perturbed by PR poly-dipeptides partially overlapped with those perturbed by the designed NLS peptide, suggesting that PR poly-dipeptides target the NLS binding site of Kapβ2. The findings offer mechanistic insights into how phase transitions of RBPs are disabled in C9orf72-related neurodegeneration

<所内学術研究成果報告>H. 「環境保全・地球環境温暖化防止をターゲットとする新パルプ資源ケナフの栽培と利用に関する研究」

本研究は, エコマテリアルとしての非木材繊維資源に最も適切である一年生植物ケナフ(Hibiscus cannabinus L.)の栽培とその利用を目的に, 1993年より開始した研究である。従来の成果は, すでに本年報1992,\u2794,\u2795,\u2796,\u2797,\u2798,および\u2799年に報告した。特に従来のケナフ栽培の成果の総決算として, 1998年より平塚市および平塚ケナフ普及協会との共同研究が行われてきた。特に, 平塚市では休耕田対策としてケナフの栽培を推奨し, 現在, 栽培したケナフのパルプ化と紙製造を行って市政に還元している。この現状はさらに展開し, 平塚市のみならず日本全国にその輪が広がり大きな活動となっている。これらの栽培や利用は最も基礎的な指導と, より学術的な研究成果の提供が常に必要であり, この点を最も重要な課題としている。さらに, 環境教育に対する展開を学校, 公民館などを中心に行い, 2000年度は, 平塚キャンパスで市内6小学校の生徒28名のケナフ教育を行った。まお, 研究室内では, 栽培研究の他に, a)種子の発芽阻害実験, b)海水による阻害実験, c)生長に伴うクロロフィル量および水分量の測定実験, d)光合成測定実験, e)花の成分(色素)研究, f)葉など各器官の成分研究などを行っている。取り扱った種類も, ローゼル(H. sabdariffa L.)類も加えると30種に近い

When can academic researchers rest? An event history analysis on researchers’ research productivity and promotion in academia from 1980 to 2016 in Japan

This study analyzed the factors required for a researcher to become a professor in the humanities and sociology, science and engineering, medicine and biology, and general studies fields. The study focuses on research productivity and analyzes the impact of hiatuses in research production on promotion in universities as well as the time at which such hiatuses have the least impact on promotions. I divided the factors required for promotion into three categories: academic performance (the number of published articles, books, and competitive grants and funding sources acquired), social elements (gender), and elements related to the duration of periods with no research output and their timing. The results show that the probability of promotion to professorship increases as the number of papers in Scopus, the number of books published, and the amount of acquired competitive funds increase. As expected, longer declines in research productivity reduce the probability of promotion. However, it is not always necessary for researchers to publish continuously throughout their careers; the results show that a decline in research productivity other than during the first five years and the period from 20 to 30 years after the start of the research career has no influence on academic promotions

Intimate Partner Violence during Pregnancy and Postpartum Depression in Japan: A Cross-sectional Study

BackgroundThe impact of intimate partner violence (IPV) on postpartum depression (PPD) has been reported in various countries by many studies. However, the association between IPV and PPD in Japan has been scarce. In addition to the limited number of research on the relationship between IPV and PPD, the number of women seeking help from IPV support centers has been steadily increasing in Japan. Hence, it is of interest to explore the relationship between IPV during pregnancy and PPD in Japan.MethodsFour-page questionnaires assessing sociodemographic characteristics, women’s personal situation during pregnancy, and PPD were mailed to participants prior to the checkup and collected at the checkup sites or mailed back to the health center. Of 9,707 eligible mothers, 6,590 responded to a questionnaire at a 3- or 4-month infant health checkup (response rate: 68%). Verbal and physical IPV from partners was assessed with two questions in the questionnaire. Logistic regression analysis was conducted. PPD was evaluated using the Edinburgh Postnatal Depression Scale (EPDS) with a cutoff score of 8/9.ResultsPartners’ verbal and physical abuse during pregnancy was significantly associated with PPD after adjusting for possible confounders. Specifically, odds ratios (ORs) of PPD for women who had been verbally abused by their partners during pregnancy at a frequency of “often” were 4.85 (95% CI, 2.23–10.55). ORs of PPD among women who had been physically abused by their partners during pregnancy at a frequency of “sometimes or often” were 7.05 (95% CI, 2.76–17.98). A positive dose-response relationship between both types of IPV and PPD was statistically significant (both p &lt; 0.001). In addition, about 80% of physically abused women reported being verbally abused as well, indicating that these forms of IPV were highly comorbid.ConclusionBoth verbal and physical IPV during pregnancy is associated with PPD in Japan. This is the first study investigating the impact of IPV on PPD using a large number of subjects in the country. Further study using the same participants of the current study would allow us to explore the causality between IPV during pregnancy and PPD