传统制造业集群协同演进机制探析——天津自行车集群纵向案例研究     

张红娟  谭劲松 《科学学与科学技术管理》2011,32(4)

产业集群对区域乃至国家经济发展具有重要的作用,然而产业集群发展过程中的影响因素及其相互作用机制至今仍未得到系统的阐述.从协同演进理论视角,结合组织生态学、制度理论、战略管理理论和社会网络理论等,对天津自行车产业集群的发展历程展开多层次、时间序列的分析,以深入挖掘产业集群发展过程中各种要素的相互作用、协同演进机制,提出产业集群的发展是企业战略、产业环境以及制度环境协同演进的过程,同时集群发展过程中创业者的社会资本发挥重要作用.这种将多维理论视角相结合起来进行分析的方法,有利于更好地理解产业集群的演进机制.  相似文献   

On Rest-from-Deliberate-Learning as a Mechanism for the Spacing Effect: Commentary on Chen et al. (2021)     

Sana  Faria  Yan  Veronica X.  Carvalho  Paulo F. 《Educational Psychology Review》2022,34(3):1843-1850

Educational Psychology Review - In their recent paper, Chen et al. (Educational Psychology Review, 2021) propose that rest periods between deliberate learning characterize the spacing effect and...  相似文献   

Beginning Science Teachers’ Use of a Digital Video Annotation Tool to Promote Reflective Practices     

Justin McFadden  Joshua Ellis  Tasneem Anwar  Gillian Roehrig 《Journal of Science Education and Technology》2014,23(3):458-470

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ZNF533、DOCK4和IMMP2L基因多态性与中国东北汉族孤独症的关联研究(英文)     

Shuang LIANG  Xue-lai WANG  Ming-yang ZOU  Han WANG  Xue ZHOU  Cai-hong SUN  Wei XIA  Li-jie WU  Takashi X. FUJISAWA  Akemi TOMODA 《Journal of Zhejiang University. Science. B》2014,(3)

研究目的:ZNF533、DOCK4和IMMP2L在大脑发育过程中起到非常重要的作用,是孤独症研究的候选基因。高加索人群的研究结果发现,ZNF533、DOCK4和IMMP2L基因的5个单核苷酸多态性(SNP)位点与孤独症高度相关。为了探讨上述位点是否与中国孤独症发生相关,我们开展了东北汉族孤独症的核心家系研究。创新要点:孤独症候选基因多态位点的研究结果通常很难得到重复。本研究首次在中国东北汉族人群中验证了与高加索人群孤独症密切相关的候选位点。这一结果对孤独症的研究具有重要指导意义。研究方法:利用SNaPshot的方法,检测了中国东北汉族370个核心家系中ZNF533(rs11885327、rs1964081)、DOCK4(rs2217262)和IMMP2L(rs12537269、rs1528039)的分布情况,利用传递不平衡检验(TDT)分析了这些多态位点与孤独症发生的相关性。重要结论:ZNF533和DOCK4基因多态性与中国北方汉族孤独症发生存在显著关联。  相似文献   

Family-based association study of ZNF533, DOCK4 and IMMP2L gene polymorphisms linked to autism in a northeastern Chinese Han population简     

Shuang LIANG  Xue-lai WANG  Ming-yang ZOU  Han WANG  Xue ZHOU  Cai-hong SUN  Wei XIA  Li-jie WU  Takashi X. FUJISAWA  Akemi TOMODA 《Journal of Zhejiang University. Science. B》2014,15(3):264-271

Objective

A study in a Caucasian population has identified two single-nucleotide polymorphisms (SNPs) in ZNF533, one in DOCK4, and two in IMMP2L, which were all significantly associated with autism. They are located in AUTS1 and AUTS5, which have been identified as autism susceptibility loci in several genome-wide screens. The present study aimed to investigate whether ZNF533, DOCK4, and IMMP2L genes are also associated with autism in a northeastern Chinese Han population.

Methods

We performed a similar association study using families with three individuals (one autistic child and two unaffected parents). A family-based transmission disequilibrium test (TDT) was used to analyze the results.

Results

There were significant associations between autism and the two SNPs of ZNF533 gene (rs11885327: χ ²=4.5200, P=0.0335; rs1964081: χ ²=4.2610, P=0.0390) and the SNP of DOCK4 gene (rs2217262: χ ²=5.3430, P=0.0208).

Conclusions

Our data suggest that ZNF533 and DOCK4 genes are linked to a predisposition to autism in the northeastern Chinese Han population.  相似文献   

Benzodiazepine administration prevents the use of error-correction mechanisms during fear extinction     

Genevra Hart  Nathan M. Holmes  Justin A. Harris  R. Frederick Westbrook 《Learning & behavior》2014,42(4):383-397

Three experiments examined the effect of systemic administration of the benzodiazepine midazolam on extinction and re-extinction of conditioned fear. Experiment 1 demonstrated that midazolam administration prior to extinction of a conditioned stimulus (CS) impaired that extinction when rats were subsequently tested drug free; however, extinction was spared if rats were extinguished, reconditioned, and re-extinguished under midazolam. Experiment 2 provided a replication of this effect within-subjects; rats were conditioned to two CSs (A and B), extinguished to one (A-), reconditioned to both, and then extinguished/re-extinguished to both stimuli in compound (AB-), under either vehicle or midazolam. On the drug-free test, rats given midazolam froze more to the CS that had been extinguished (B) than the one that been re-extinguished (A). The final experiment examined whether extinction under midazolam was regulated by prediction error. Rats were trained with three CSs (A, B, C) and extinguished to two (A-, C-). These stimuli then underwent additional extinction under midazolam or vehicle, with one CS now presented in compound with the non-extinguished CS (AB-, C-). Rats were then tested for fear of A relative to C. Rats given vehicle showed a deepening of extinction to A relative to C, as is predicted from error-correction models; however, rats given midazolam failed to show any such discrepancy in responding. The results are interpreted to indicate that the drug reduced prediction error during extinction by reducing fear, and rats were able to re-extinguish fear via a retrieval mechanism that is independent of prediction error.  相似文献   

知识考古与历史重诂:编撰《林纾年谱长编》的构想     

张旭  车树昇 《福建工程学院学报》2014,(2):107-110,120

论述编撰《林纾年谱长编》的总体构想。课题尝试运用现代史学方法对近代闽籍历史名人林纾进行知识考古和重诂,涉及谱主一生四个不同特质的时期。介绍这项课题的选题背景、动机和主要任务,同时提出年谱编撰方法方面的新观点。研究的目的是以新的历史观重构特定时期的历史人物。  相似文献   

Gender and ethnic differences in perceptions of equal opportunity climate and job outcomes of US Army Reserve component personnel     

Armando X. Estrada  Colin R. Harbke 《Int J Intercult Relat》2008,32(5):466-478

We examined equal opportunity climate (EOC) perceptions of reserve component personnel in the US Army (n = 949). We expected that gender and ethnic group membership would influence perceptions of the equal opportunity climate; and that gender and ethnic group membership would moderate the relationship between equal opportunity climate perceptions and ratings of job satisfaction, organizational commitment and workgroup effectiveness. Consistent with our hypothesis, we found the women and minorities perceptions regarding the equal opportunity climate were less favorable than White men. We also found that both gender and ethnicity moderated the relationship between equal opportunity climate perceptions and job outcomes of these groups. Our findings suggest that different groups are sensitive to particular aspects of EOC (e.g., harassment or discrimination) and that these sensitivities affect job-related outcomes.  相似文献   

The development,field test and validation of an inventory of scientific attitudes     

Richard W. Moore  Frank X. Sutman 《科学教学研究杂志》1970,7(2):85-94

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Geometrical effects in microfluidic-based microarrays for rapid, efficient single-cell capture of mammalian stem cells and plant cells     

Lawrenz A  Nason F  Cooper-White JJ 《Biomicrofluidics》2012,6(2):24112-2411217

In this paper, a detailed numerical and experimental investigation into the optimisation of hydrodynamic micro-trapping arrays for high-throughput capture of single polystyrene (PS) microparticles and three different types of live cells at trapping times of 30 min or less is described. Four different trap geometries (triangular, square, conical, and elliptical) were investigated within three different device generations, in which device architecture, channel geometry, inter-trap spacing, trap size, and trap density were varied. Numerical simulation confirmed that (1) the calculated device dimensions permitted partitioned flow between the main channel and the trap channel, and further, preferential flow through the trap channel in the absence of any obstruction; (2) different trap shapes, all having the same dimensional parameters in terms of depth, trapping channel lengths and widths, main channel lengths and widths, produce contrasting streamline plots and that the interaction of the fluid with the different geometries can produce areas of stagnated flow or distorted field lines; and (3) that once trapped, any motion of the trapped particle or cell or a shift in its configuration within the trap can result in significant increases in pressures on the cell surface and variations in the shear stress distribution across the cell’s surface. Numerical outcomes were then validated experimentally in terms of the impact of these variations in device design elements on the percent occupancy of the trapping array (with one or more particles or cells) within these targeted short timeframes. Limitations on obtaining high trap occupancies in the devices were shown to be primarily a result of particle aggregation, channel clogging and the trap aperture size. These limitations could be overcome somewhat by optimisation of these device design elements and other operational variables, such as the average carrier fluid velocity. For example, for the 20 μm polystyrene microparticles, the number of filled traps increased from 32% to 42% during 5–10 min experiments in devices with smaller apertures. Similarly, a 40%–60% reduction in trapping channel size resulted in an increase in the amount of filled traps, from 0% to almost 90% in 10 min, for the human bone marrow derived mesenchymal stem cells, and 15%–85% in 15 min for the human embryonic stem cells. Last, a reduction of the average carrier fluid velocity by 50% resulted in an increase from 80% to 92% occupancy of single algae cells in traps. Interestingly, changes in the physical properties of the species being trapped also had a substantial impact, as regardless of the trap shape, higher percent occupancies were observed with cells compared to single PS microparticles in the same device, even though they are of approximately the same size. This investigation showed that in microfluidic single cell capture arrays, the trap shape that maximizes cell viability is not necessarily the most efficient for high-speed single cell capture. However, high-speed trapping configurations for delicate mammalian cells are possible but must be optimised for each cell type and designed principally in accordance with the trap size to cell size ratio.  相似文献