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Mito-shi, Japan

Tokiwa University is a private university in Mito, Ibaraki, Japan, established in 1983. The predecessor of the school was founded in 1909.California State University, Fresno & California State University, Northridge's Japanese Department has had an active international student exchange program with this university since 2004. Wikipedia.

Iwata T.,The Institute of Statistical Mathematics of Tokyo | Iwata T.,Tokiwa University
Pure and Applied Geophysics | Year: 2016

The model based on rate- and state-dependent friction law reproduces the temporal decay of an aftershock sequence with the p value of the Omori–Utsu law equal to 1, if we simply assume a constant stress rate over time. However, because p values vary in real aftershock sequences, this model requires some modification. This study examined the effect of secondary aftershocks on the variety of the p value. A large aftershock causes a stepwise stress increase in the aftershock area, and the expected seismicity rate derived from the friction law also increases abruptly. These multiple increases in the seismicity rate during its decay following a mainshock could cause variation in the apparent p value. In this study, a model incorporating this idea is applied to two aftershock sequences observed in Japan and is shown to substantially modify the modeling of aftershock activity. © 2015, Springer Basel. Source

Popovski V.,University of Tokyo | Mundy K.G.,Tokiwa University
Sustainability Science | Year: 2012

This article introduces the concept of "climate-change victims" and classifies categories of threats and groups of people who would be vulnerable to and victimized by human-induced climate change. (The full, correct wording is "human-induced climate-change victims", but we will use just "climate-change victims" in the rest of the article.) It offers a definition with three levels of climate-change victimization and differentiates "climate-change victims" from "natural-disasters victims" and from "climate-change migrants". The article sets an agenda for a new type of victimhood and could lead to further research on possible prevention, accountability measures, environmental tribunals, and compensation mechanisms to recompense climate-change victims. © 2011 Integrated Research System for Sustainability Science, United Nations University, and Springer. Source

Hamatani R.,Tokyo Womens Medical University | Otsu M.,Tokyo Womens Medical University | Otsu M.,Tokiwa University | Chikamoto H.,Tokyo Womens Medical University | And 2 more authors.
Clinical and Experimental Nephrology | Year: 2014

Background: Hyperhomocysteinemia (hyper-Hcy) is an important and reversible cardiovascular disease risk factor. We examined the prevalence of hyper-Hcy, plasma folate levels, and dietary folate intake in adolescents and young adults who had undergone kidney transplantation during childhood to assess the necessity for managing dietary folate. Methods: This cross-sectional study was performed in 89 kidney transplant recipients (age at kidney transplantation: 12.6 ± 4.1 years; age during study: 21.2 ± 5.5 years). Hyper-Hcy and plasma folate deficiency were defined as plasma homocysteine (Hcy) >15 nmol/ml and plasma folate <3.0 ng/ml, respectively. Results: Of the patients, 60 (67.4 %) had hyper-Hcy and 14 (15.7 %) had plasma folate deficiency. Plasma homocysteine levels correlated negatively with estimated glomerular filtration rate (eGFR; r = -0.565, p < 0.01) and plasma folate levels (r = -0.434, p < 0.01). For determinants of plasma homocysteine levels, a priori selected variables included kind of calcineurin inhibitor, age at kidney transplantation, pretransplant duration of dialysis, time since transplantation, age at examination, eGFR, and plasma folate. Stepwise multiple linear regression analysis revealed eGFR and plasma folate levels as significant independent variables influencing plasma homocysteine levels. Dietary folate intake in 11 of 16 patients (66.8 %) with eGFR ≥60 ml/min/1.73 m2 was below the recommended dietary allowance for Japanese. Conclusions: The prevalence of hyper-Hcy and plasma folate deficiency, as well as the low dietary folate intake, suggest that dietary management of folate is necessary for adolescents and young adults who have undergone kidney transplantation during childhood. © 2013 Japanese Society of Nephrology. Source

Nakahara F.,Tokiwa University | Miyazaki N.,University of Tokyo
Journal of Ethology | Year: 2011

Bottlenose dolphins (Tursiops truncatus) produce individually distinctive vocalizations-referred to as "signature whistles"-that are thought to function as an individual and conspecific recognition system for maintenance of consistent contact between individuals. Observations and playback experiments were conducted at aquariums to study these whistle-vocal exchanges in bottlenose dolphins. Temporal patterns of vocalization were examined by analyzing the intercall intervals between two consecutive whistles. When a second individual produced a call that was different from the first individual's vocalization, most of these calls were shorter than 1 s. However, when two consecutive calls were produced by the same individual, the second call rarely occurred within 1 s of the first. These results suggest that a second whistle may be produced by a different caller in response to the first whistle; however, in the case of an absence of a response, the first caller is likely to give further whistles. The results of this acoustic analysis show that the dolphins used in this study mostly used signature whistles during the recorded vocal exchanges. © 2011 Japan Ethological Society and Springer. Source

Miyagawa Y.,National Health Research Institute | Okita H.,National Health Research Institute | Hiroyama M.,SCIVAX Corporation | Sakamoto R.,SCIVAX Corporation | And 8 more authors.
Tissue Engineering - Part A | Year: 2011

Here, we report the highly efficient in vitro differentiation of human bone marrow-derived mesenchymal stem/progenitor cells (MPCs) using a novel nanotechnology-based culture plate, nanoculture plate® (NCP). The NCP contains uneven microfabrications with diameters of ∼2-3μm arranged in a honeycomb pattern on its culture surface, which is devoid of animal-derived protein sources. When human MPCs were subjected to three-dimensional (3D) culture using an NCP, they rapidly formed adhesive spheroids. We showed that adipogenic differentiation in NCP-mediated 3D cultures led to more rapid accumulation of triglycerides than that in two-dimensional cultures. During adipogenesis in 3D cultures, the rapid and intense induction of adipocyte-specific gene expressions, such as peroxisome proliferator-activated receptor γ (PPAR-γ), CCAAT-enhancer-binding protein α (C/EBP-α), adipocyte protein 2 (aP2), and adiponectin was observed. Together, these results indicate that this 3D culture system is suitable for the differentiation of human MPCs into adipogenic lineage, and could be applicable to adipose tissue engineering under xeno-free condition. © 2011 Mary Ann Liebert, Inc. Source

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