Cell-induced flow-focusing instability in gelatin methacrylate microdroplet generation

Photo-crosslinkable gelatin methacrylate (GelMa) microspheres are applicable to deliver cells or drugs in biological or biomedical applications. To fabricate GelMa microdroplets, a flow focusing technique with advantages of size control and rapid production was used in a T-junction microfluidic device. Instability played an important role in promoting microdroplet uniformity. 5 wt. % GelMa prepolymer solution mixed with cells affected cell-induced instability. At low flow rate ratio of GelMa to mineral oil below 0.200, stability was maintained regardless of GelMa concentration (5 and 8 wt. %) and cell presence, which led to uniform microdroplet generation. In contrast, instability at high flow rate ratio above 0.200 was worsened by cell presence and unstable jetting length, resulting in the generation of non-uniform cell-laden microdroplets. Therefore, the effect of cell-induced instability on microdroplet generation was minimized at a low flow rate ratio.     

A study of Korean middle school students’ interests in biology and their implications for biology education

This study analyses middle school students’ interests in biology to provide information on instructional strategies and curriculum development in Korea. An instrument that measures interests was developed based on the middle school biology curriculum. It consists of 64 three‐point Likert‐type items (scores range from 0 to 2). The two components, ‘topic’ and ‘activity’, are composed of 64 items. The topic component and the activity component contain 11 domains and six domains respectively. Data were collected from 267 middle school students in Seoul (male: 169, female: 107). The levels of interest in topic and activity were almost the same and not high. The highest interest domains were ‘genetics’ in topics and ‘observing through a microscope’ in activities. The interest levels in the domain ‘plant morphology’ and ‘plant‐related activity’ were the lowest in each component. The interest level of the eighth graders was the highest found among students. Interest levels of females were lower than those of males in ‘environment and ecosystem’, ‘animal reproduction’ and ‘animal morphology’, but higher in ‘plant morphology’ and ‘plant related activity’ (p < 0.05). Among the topics, the ‘human biology’ domain correlated positively with the domains ‘genetics’, ‘environment and ecosystem’ and ‘respiration of animal and plant’. The correlation between the domains of ‘plant reproduction and nutrition’ and ‘plant development’ was significant in ‘activity’ (r > 0.50, p < 0.001). Consistencies in interests were suggested with respect to instructional strategy and curriculum design.     

The social,economic and political contexts of adults' participation in undergraduate programmes: a state-level analysis

This study examined the extent to which socially structured factors impact adults' participation in undergraduate programmes in the USA. In a collective sense, this study started with an assumption that adults' decision to participate in educational programmes does not only rely on individual psychological and their adjacent environmental attributes, but it is also, in part, influenced by socially structured contexts surrounding them. Using the state as a unit of analysis, this study analysed the relationships between socio-demographic, economic, educational and political factors and the variation of adults' participation in the undergraduate programmes. Variables from both educational and socio-demographic factors had stronger relationships with adults' participation. Some variables that states can control through policy-related actions were meaningfully associated with adults' participation. Through this sociological understanding of adult participation in higher education, this study will supplement the lack of attention to macro-level perspectives in participation research in adult education.     

Is Pedagogical Content Knowledge (PCK) Necessary for Reformed Science Teaching?: Evidence from an Empirical Study

This study tested a hypothesis that focused on whether or not teachers’ pedagogical content knowledge (PCK) is a necessary body of knowledge for reformed science teaching. This study utilized a quantitative research method to investigate the correlation between a teacher’s PCK level as measured by the PCK rubric (Park et al. 2008) and the degree to which his/her classroom is reform-oriented as measured by RTOP (Sawada et al. 2002). Data included 33 instructional sessions of photosynthesis and heredity videotaped with 7 high school biology teachers. Each session was given a score on both the PCK rubric and RTOP by two independent raters. Results indicate that PCK score is significantly related to RTOP score in terms of both total score (r = .831, p < .01) and sub-component scores (ranging from r = .616 to .805, p < .01). Implications for science teacher education and future research are discussed.     

Learning to Scaffold Science Academic Language: Lessons from an Instructional Coaching Partnership

Research in Science Education - Engagement in meaningful and authentic science learning requires students to access not only the science content and practices but also the academic language...     

Women academics and research productivity: an international comparison

In the prestige economy of higher education, research productivity is highly prized. Previous research indicates, however, a gender gap with respect to research output. This gap is often explained by reference to familial status and responsibilities. In this article, we examine the research productivity gender gap from an international perspective by undertaking a gendered analysis of the Changing Academic Profession Survey. We suggest that family is not, in all cases, operating as a form of negative equity in the prestige economy of higher education. In addition, we argue that an over-reliance on an explanatory framework that positions family-related variables as central to the research productivity gender gap might well be drawing our attention from significant structural and systemic discriminatory practices within the profession.     

Comparisons of Three Empirical Methods for Partial Factorial Invariance: Forward,Backward, and Factor-Ratio Tests

When factorial invariance is violated, a possible first step in locating the source of violation(s) might be to pursue partial factorial invariance (PFI). Two commonly used methods for PFI are sequential use of the modification index (backward MI method) and the factor-ratio test. In this study, we propose a simple forward method using the confidence interval (forward CI method). We compare the performances of the aforementioned 3 methods under various simulated PFI conditions. Results indicate that the forward CI method using 99% CIs has the highest perfect recovery rates and the lowest Type I error rates. A performance that is competitive with this is that produced by the backward method with the more conservative criterion (MI = 6.635). Consistently delivering the poorest performance, regardless of the chosen confidence level, was the factor-ratio test. Also discussed are the work’s contribution, implications, and limitations.     

开放远程教育成本效益研究的现状及思考

有关开放远程教育成本效益的早期研究表明,远程教育比面授教育更具成本效益。远程教育的成本主要取决于两个方面:入读学生人数;课程开发和传递的固定成本。然而,分析网上教育成本效益的实证研究可谓相当缺乏。本文首先介绍一些早期关于开放远程教育成本效益的研究结果;进而描述最近的网上教育的成本效益研究;最后,文章探讨了开放远程教育的重要主题,并对未来研究的领域提出了建设性提议。     

Theaters of war: Tracing the strange careers of Shina No Yoru in the military contact zones of the Pacific, 1937–1954

This article examines the ways in which multiple traditions of camp shows and the overlapping and relational layers of Imperial Japan and U.S. presence in Korea shaped Korean entertainers’ lives after 1945, producing their idiosyncratic performances in response to rapid shifts in Korea’s relations with Japan and the United States in the 1940s–1950s. When the United States sought to reposition Japan at the top of the newly emerging American hegemonic order of Asian countries, Korean entertainers who served the Imperial Japanese Army a few months earlier found themselves performing for American soldiers. The stage of the Korean native camp shows became a “strange and exotic” yet “familiar and even comforting” place where inconsistent logics, such as Imperial Japan’s pan-Asian ideology and American Orientalist fantasy, mingled. Under the complicated legacies of overlapping militarization and colonization in Korea, militarization has constituted a structuring force that enabled Korean women camp show entertainers generating their hybrid performance styles in ironies, contradictions, and complexities. Building on postcolonial theorists’ notion of hybridity, I argue that Korean entertainers’ performances were being shaped or negotiated in contact with different audiences and expectations as well as Korean entertainers attempted to navigate the acceptable ground of performances and womanhood in the constantly changing political and ideological environment.