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81.
国产十种乌头的染色体研究   总被引:1,自引:0,他引:1  
本文描述了我国产毛茛科乌头属的10个种的染色体数目和形态。  根据该属染色体基 数为8(x=8),可将这些种归为二倍体、四倍体、六倍体和八倍体种。  10种乌头的染色体在数目、大小、结构上表现出相关性。其中具根状茎而多年生的种多为二倍体,染色体形态较大,第3-7号多为近端着丝点(st)染色体, 具块茎而二年生的种多为多倍体,染色体形态较小,第3-7号多为近中着丝点(sm)染色体。染色体演化方向可能是二倍体→多倍体、大→ 小、st→sm。这进一步证明根状茎种较块茎种原始。根据染色体数目和形态,又可将这些种的染色体分为两类。这进一步支持了目前分类学上的牛扁亚属和乌头亚属的划分。本文还讨论了这些种的有关分类问题。  相似文献   
82.
Concurrent droplet charging and sorting by electrostatic actuation   总被引:1,自引:0,他引:1  
This paper presents a droplet-based microfluidic device for concurrent droplet charging and sorting by electrostatic actuation. Water-in-oil droplets can be charged on generation by synchronized electrostatic actuation. Then, simultaneously, the precharged droplets can be electrostatically steered into any designated laminar streamline, thus they can be sorted into one of multiple sorting channels one by one in a controlled fashion. In this paper, we studied the size dependence of the water droplets under various relative flow rates of water and oil. We demonstrated the concurrent charging and sorting of up to 600 droplets∕s by synchronized electrostatic actuation. Finally, we investigated optimized voltages for stable droplet charging and sorting. This is an essential enabling technology for fast, robust, and multiplexed sorting of microdroplets, and for the droplet-based microfluidic systems.  相似文献   
83.
For the last 70 years, since the establishment of the Republic of Korea, Korean education has achieved universal expansion of educational opportunity from elementary to secondary to higher education. Planning, centralized policy making, top-down implementation, and administrative control had been the standards of the first few decades of Korean education. The so-called May 31 education reform implemented in 1995 made a turning point for these approaches to education policy and administration by highlighting autonomy, openness, diversity, accountability, consumer centeredness, market control, and governance for quality education. However, these government-driven education reform initiatives have resulted in limiting the expected outcomes. In this paper, the authors call for a new approach to education policy and administration and propose supporting school innovation, empowering an internal accountability system in governance. The authors also suggest a search for normative values for democratic communitarianism as a new philosophical foundation of education policy framework, beyond instrumental values of education.  相似文献   
84.
Abstract

Over the last decade, school-based professional learning communities (PLCs) have emerged as a key feature of the education system in South Korea. To understand this relatively new phenomenon in the context of South Korea, we provide a review of research on school-based PLCs in South Korea and an empirical analysis of the Teaching and Learning International Survey (TALIS) 2008 with a focus on school-based PLCs. Based on our findings from the literature review and analysis of the TALIS, we aim to provide a fuller picture of the emerging landscape of school-based PLCs in South Korean schools. In so doing, we focus on what constitutes school-based PLCs in South Korean schools and how they are similar to and/or different from their counterparts in other countries. Implications for policy, practice, and research are discussed.  相似文献   
85.
ABSTRACT

Accommodating non-binary transgender people, many of whom use gender-neutral pronouns, poses a unique challenge to schools and universities, even in contexts with legal protections for transgender rights. This article explores a recent Canadian controversy around gender-neutral pronouns, and assembles a theoretical framework to analyze the argument that legal protection for transgender peoples’ pronouns poses a threat to ‘free speech.’ The framework bridges queer theory, affect theory and Deleuzo-Guattarian assemblage theory to propose a threshold between ‘extra’ and ‘excessive’ effort to accommodate social difference in everyday life. Free speech objections produce some peoples’ pronouns as requiring ‘excessive’ effort. This extra/excessive framework was exemplified by a recent Canadian social media campaign that sought to produce transgender peoples’ pronouns as requiring merely ‘extra’ effort, which entails de-politicizing pronouns. Community responses to the campaign carry significant implications for gender-expansive educational policy and practice.  相似文献   
86.
87.
Many studies examine student self-concept during compulsory schooling but few have explored the self-concept of students in higher educational settings. The current study examined self-concept by faculty and gender among higher education students in New Zealand. Participants were 929 undergraduate students from a large New Zealand university. The results showed some differences in verbal and maths self-concept by faculty. Generally, students in faculties teaching subjects more reliant on maths skills had higher maths self-concept than those in faculties where facility in verbal skills was important. The opposite results were found for verbal self-concept. No overall gender differences were found for general, academic, verbal and maths self-concept although a statistically significant difference was found for problem-solving self-concept. This finding suggests students’ choice of faculty may be based on perceptions of their skills and capabilities in the various fields, irrespective of gender.  相似文献   
88.
The relative importance of mental effort, as indicated by strategy use, and persistence as potential mediators of the memory self-efficacy (MSE)/memory performance relationship was investigated within a sample of 26 adults aged 65 years and older. It was found that persistence but not strategy use was predictive of performance on a free-recall task. Age-related declines were found in persistence, performance, and MSE but not in strategy use. Counter to expectation, neither strategy use nor persistence was significantly related to a global measure of MSE. These results highlight the importance in MSE research of distinguishing mental effort and persistence, of task-specific measures of MSE, and of considering age-related changes within the elderly population. Implications for MSE intervention programs are briefly discussed.  相似文献   
89.
ABSTRACT

In Taiwan, there are service learning programs organized by older adult educational institutions that are held in high esteem. Director leadership plays a key role in the effectiveness of such institutions, and the leadership experiences of such directors in guiding service learning are worth exploring. This study conducted a qualitative approach and selected directors from eight Active Aging Learning Centers (AALCs) who achieved outstanding leadership effectiveness to take part in one-on-one and in-depth semi-structured interviews. The results indicated that: 1. Directors infused the entire service learning process with inspirational motivation by adopting through individualized consideration as a starting point. 2. When directors led the preparation process for service learning, they focused on inducing intellectual stimulation among the older adult learners, such that they felt empowered and capable of providing community services. 3. During the community service phase, directors practiced a form of leadership characterized by idealized influence to encourage, accompany, and support the elderly while they engaged in service learning. 4. The dilemma faced by directors was dissatisfaction with the leadership. Directors responded by reminding them of their original service learning intention and downplaying issues, which made the service learning group undergo a positive transformation. 5. The results of directors’ leadership had a positive effect on the community as it led to more dynamism and more people participating in community service.  相似文献   
90.
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