神经干细胞体外诱导分化的研究进展

神经干细胞是近年来脑科学研究的热点,其自我更新和多向分化的潜能为中枢神经系统疾病的治疗提供了可能,但如何使神经干细胞向特定的方向分化却一直是研究的难点。本文对神经干细胞体外的诱导分化因素及分化过程中的相关蛋白质组的研究做一综述。     

城郊失地农民的社会角色转换

随着城市化进程的推进,失地农民数量激增。如何使这一群体实现社会角色的转变,变成真正意义上的城市居民,是当前城市化进程中一个亟待解决的重大问题。目前城郊农民角色转换中面临内在动力不足等现实困境,需要城郊失地农民通过自身的努力,增强生存和发展能力;更需要政府积极作为,加快制度创新,完善公共政策,为城郊失地农民实现角色转换提供制度保障。     

When Costs Are Unequal and Unknown: A Subtree Grafting Approach for Unbalanced Data Classification*

In binary classifications, a decision tree learned from unbalanced data typically creates an important challenge related to the high misclassification rate of the minority class. Assigning different misclassification costs can address this problem, though usually at the cost of accuracy for the majority class. This effect can be particularly hazardous if the costs cannot be specified precisely. When the costs are unknown or difficult to determine, decision makers may prefer a classifier with more balanced accuracy for both classes rather than a standard or cost‐sensitively learned one. In the context of learning trees, this research therefore proposes a new tree induction approach called subtree grafting (STG). On the basis of a real bank data set and several other data sets, we test the proposed STG method and find that our proposed approach provides a successful compromise between standard and cost‐sensitive trees.     

尖镰孢菌F.oxysporum L19内切纤维素酶诱导碳源的研究

以在自然界中筛选到的一株产纤维素酶的丝状真菌尖镰孢菌F.oxysporumL19为材料,定时测定尖镰孢菌在10种碳源中的纤维素酶活力,发现酶的合成受培养基中碳源种类的调节控制。结构相对完整的纤维类物质(微晶纤维素、TYPE50、CMC、醋酸纤维素)诱导活性较高,二糖(乳糖、麦芽糖、蔗糖)和单糖(葡萄糖和D-木糖)几乎没有诱导作用,麸皮汁液体培养液表现出了较高的诱导活力。菌丝在麸皮汁培养液上的生长状况的研究表明,菌丝的生长情况与酶的产生存在不同步性。这为下一步酶的纯化和分子生物学的研究中选择不同生长期的培养也提供了依据。     

Women’s experiences of decision-making and attitudes in relation to induction of labour: A survey study

BackgroundRates of induction of labour have been increasing globally to up to one in three pregnancies in many high-income countries. Although guidelines around induction, and strength of the underlying evidence, vary considerably by indication, shared decision-making is increasingly recognised as key. The aim of this study was to identify women’s mode of birth preferences and experiences of shared decision-making for induction of labour.MethodAn antenatal survey of women booked for an induction at eight Sydney hospitals was conducted. A bespoke questionnaire was created assessing women’s demographics, indication for induction, pregnancy model of care, initial birth preferences, and their experience of the decision-making process.ResultsOf 189 survey respondents (58% nulliparous), major reported reasons for induction included prolonged pregnancy (38%), diabetes (25%), and suspected fetal growth restriction (8%). Most respondents (72%) had hoped to labour spontaneously. Major findings included 19% of women not feeling like they had a choice about induction of labour, 26% not feeling adequately informed (or uncertain if informed), 17% not being given alternatives, and 30% not receiving any written information on induction of labour. Qualitative responses highlight a desire of women to be more actively involved in decision-making.ConclusionA substantial minority of women did not feel adequately informed or prepared, and indicated they were not given alternatives to induction. Suggested improvements include for face-to-face discussions to be supplemented with written information, and for shared decision-making interventions, such as the introduction of decision aids and training, to be implemented and evaluated.     

中国钢铁产业关联效应及国际比较分析

 本文应用投入产出表计算了中国钢铁产业关联效应及其国际比较,并分析了各项最终需求对钢铁产业生产的诱发作用。研究结果显示,我国钢铁产业对黑色金属矿采选业后向直接关联效应明显高于其它七国;包括中国、巴西等在内的发展中国家和韩国等新兴工业化国家的钢铁产业对建筑业的前向关联效应远远高于发达国家;我国钢铁产业对国民经济的拉动效应低于其它七个产钢大国,且其对我国国民经济的推动作用呈降低趋势;投资需求仍然是诱发我国钢铁产业生产的最重要因素,明显高于日本、美国等钢铁强国,也高于印度和巴西等钢产量很大的发展中国家;出口需求对钢铁产业生产的拉动效应明显低于钢产量远小于中国的日本等OECD国家。     

浅谈大学英语词汇教学中的文化导入

词汇教学是大学英语教学中的一个重要组成部分。本文从语言和文化的关系出发,通过对目前大学英语词汇教学现状的分析,说明了文化导入在英语词汇教学中的重要性,提出英语词汇教学中文化导入的主要内容和方法,从而帮助学生提高文化敏感度,提高跨文化交际能力。     

The trend toward multiple authorship in social work: A British and US comparison

This article provides a comparative analysis of publication trends in social work in the US and Great Britain. This exploratory effort seeks to identify possible explanations for the phenomenon of multiple authorship, the implications of multi-authored scholarship, and some of the potential ethical questions that may arise from such collaborations in regard to what constitutes legitimate contributions to a scholarly article or book. To the extent that common trends are emerging across international boundaries, the incentive for heightened communication and collaboration may be increased in an effort to identify implications and derive solutions to common problems.     

基于创造性思维的色彩归纳

在培养艺术创造性思维能力方面,作为表现性绘画范畴的色彩归纳是一种必要的训练手段。它不仅是捕捉色彩元素和分析色彩关系的重要途径,而且是研究创造性地运用色彩的重要环节,在拓宽创造性思维以及协调设计方面具有特殊的作用与价值。