Discriminated and nondiscriminated avoidance conditioning of the rearing response in rats

Experiment 1 employed a shock box in which light beams ran at 10, 15, 20, or 25 cm above the floor level of the box. Four groups of nine rats each were trained to avoid shock by cutting the light beams or letting them pass by, which the animal accomplished by upward or downward change of its posture. Training employed a discriminated avoidance paradigm, 60 trials per day for 5 days, with a 5-sec CS-US interval. Acquisition of the rearing avoidance response was observed only in the 15-cm condition. Using the same apparatus as in Experiment 1 and with a beam height of 15 cm, the rearing avoidance response was successfully conditioned in five rats using a nondiscriminated avoidance conditioning paradigm. There was good evidence of temporal discrimination in these animals.     

Induction of alternative fate other than default neuronal fate of embryonic stem cells in a membrane-based two-chambered microbioreactor by cell-secreted BMP4

Cell-secreted soluble factor signaling in a diffusion dominant microenvironment plays an important role on early stage differentiation of pluripotent stem cells invivo. In this study, we utilized a membrane-based two-chambered microbioreactor (MB) to differentiate mouse embryonic stem cells (mESCs) in a diffusion dominant microenvironment of the top chamber while providing enough nutrient through the bottom chamber. Speculating that accumulated FGF4 in the small top chamber will augment neuronal differentiation in the MB culture, we first differentiated mESCs for 8 days by using a chemically optimized culture medium for neuronal induction. However, comparison of cellular morphology and expression of neuronal markers in the MB with that in the 6-well plate (6WP) indicated relatively lower neuronal differentiation in the MB culture. Therefore, to investigate whether microenvironment in the MB facilitates non-neuronal differentiation, we differentiated mESCs for 8 days by using chemically defined basal medium. In this case, differentiated cell morphology differed markedly between the MB and 6WP cultures: epithelial sheet-like morphology in the MB, whereas rosette morphology in the 6WP. Expression of markers from the three germ layers indicated lower neuronal but higher meso- and endo-dermal differentiation of mESCs in the MB than the 6WP culture. Moreover, among various cell-secreted soluble factors, BMP4 expression was remarkably upregulated in the MB culture. Inhibition of BMP4 signaling demonstrated that enhanced effect of upregulated BMP4 was responsible for the prominent meso- and endo-dermal differentiation in the MB. However, in the 6WP, downregulated BMP4 had a minimal influence on the differentiation behavior. Our study demonstrated utilization of a microbioreactor to modulate the effect of cell-secreted soluble factors by autoregulation and thereby inducing alternative self-capability of mESCs. Understanding and implementation of autoregulation of soluble factors similar to this study will lead to the development of robust culture systems to control ESC behavior.     

城市发展与环境:高等教育的任务

早上好。我是东京大学校长小宫山宏。很荣幸参加复旦大学的百年庆典。在这样的场合,提出城市和高等教育相互关系这样的话题再合适不过了。虽然城市的可持续性发展的话题已经成为世界范围内的兴趣热点,但高等教育在社会中的作用还是受到诸多质疑。在此专题讨论会中,我想就高等教育如何促进城市和环境的发展进行论述。     

Field independent probabilistic model for clustering multi-field documents

We propose a new finite mixture model for clustering multiple-field documents, such as scientific literature with distinct fields: title, abstract, keywords, main text and references. This probabilistic model, which we call field independent clustering model (FICM), incorporates the distinct word distributions of each field to integrate the discriminative abilities of each field as well as to select the most suitable component probabilistic model for each field. We evaluated the performance of FICM by applying it to the problem of clustering three-field (title, abstract and MeSH) biomedical documents from TREC 2004 and 2005 Genomics tracks, and two-field (title and abstract) news reports from Reuters-21578. Experimental results showed that FICM outperformed the classical multinomial model and the multivariate Bernoulli model, being at a statistically significant level for all the three collections. These results indicate that FICM outperformed widely-used probabilistic models for document clustering by considering the characteristics of each field. We further showed that the component model, which is consistent with the nature of the corresponding field, achieved a better performance and considering the diversity of model setting also gave a further performance improvement. An extended abstract of parts of the work presented in this paper has appeared in Zhu et al. [Zhu, S., Takigawa, I., Zhang, S., & Mamitsuka, H. (2007). A probabilistic model for clustering text documents with multiple fields. In Proceedings of the 29th European conference on information retrieval, ECIR 2007. Lecture notes in computer science (Vol. 4425, pp. 331–342)].     

Building school-university partnerships: Subjectivity,power, and the process of change

In the flurry of 1980s educational reforms, school-university collaborative partnerships appeared as a popular and promising vehicle for change. The growth of partnerships has been accompanied by an increasing knowledge about the process of change. This study, based on ethnographic and interview data, further extends the knowledge by focusing on one facet of the process: the initiation of partnership relations between a college of education and surrounding elementary and secondary schools. The study finds that the subjective perceptions of school people toward change plays a critical role in the development of partnership relations. These perceptions are grounded in the existing relations between school and university people, and in the harsh conditions of work in schools. School people's relation to these conditions, as manifest in their sense of power or powerlessness, shaped their willingness to work with the university.     

从《七发》到《天子游猎赋》——脱离上古文学传统，确立汉赋表现世界

枚乘《七发》开创了汉大赋这一体式，是司马相如《天子游猎赋》的直接祖先。但枚乘的《七发》背后还存在着古老的师承，司马相如的作品却脱离了上古文学传统，确立了汉赋的表现世界，标志着汉赋新的发展方向。     

Dynamics of submaximal effort soccer instep kicking

During a soccer match, players are often required to control the ball velocity of a kick. However, little information is available for the fundamental qualities associated with kicking at various effort levels. We aimed to illustrate segmental dynamics of the kicking leg during soccer instep kicking at submaximal efforts. The instep kicking motion of eight experienced university soccer players (height: 172.4 ± 4.6 cm, mass: 63.3 ± 5.2 kg) at 50, 75 and 100% effort levels were recorded by a motion capture system (500 Hz), while resultant ball velocities were monitored using a pair of photocells. Between the three effort levels, kinetic adjustments were clearly identified in both proximal and distal segments with significantly different (large effect sizes) angular impulses due to resultant joint and interaction moments. Also, players tended to hit an off-centre point on the ball using a more medial contact point on the foot and with the foot in a less upright position in lower effort levels. These results suggested that players control their leg swing in a context of a proximal to distal segmental sequential system and add some fine-tuning of the resultant ball velocity by changing the manner of ball impact.