Lysozyme refolding at high concentration by dilution and size-exclusion chromatography

This study of renaturation by dilution and size exclusion chromatography (SEC) addition of urea to improve yield as well as the initial and final protein concentrations showed that although urea decreased the rate of lysozyme refolding, it could suppress protein aggregation to sustain the pathway of correct refolding at high protein concentration; and that there existed an optimum urea concentration in renaturation buffer. Under the above conditions, lysozyme was successfully refolded from initial concentration of up to 40 mg/mL by dilution and 100 mg/mL by SEC, with the yield of the former being more than 40% and that of the latter being 34.8%. Especially, under the condition of 30 min interval time, i.e. τ>2(t _R2−t_R1), the efficiency was increased by 25% and the renaturation buffer could be recycled for SEC refolding in continuous operation of downstream process. Project supported by Zhejiang Provincial Natural Science Foundation of China (No. 201099) and the Local-Lab Project by Korean Institute of Science and Technology Evaluation and Planning, Korea     

An assessment of the impact of science experiences on the career choices of male and female biology students

Earlier studies of gender differences in science courses and careers have identified three probable causes: numbers of mathematics courses, level of science achievement, and attitudes toward science. Recently, differential science experiences have been suggested as a factor contributing to the gender differences found in science interest and achievement. A study of science activities, both within and outside of school, has been conducted. Although both boys and girls report similar classroom experiences, boys more often than girls report extracurricular science activities. The findings suggest that equal experiences within science classrooms do not overcome the advantage that boys hold due to more extracurricular science activities. Increased experiences in science, however, have led to more positive attitudes toward science among the girls in this study.     

The Impact of Various Class-Distinction Features on Model Selection in the Mixture Rasch Model

The purpose of the current study is to examine the performance of four information criteria (Akaike's information criterion [AIC], corrected AIC [AICC] Bayesian information criterion [BIC], sample-size adjusted BIC [SABIC]) for detecting the correct number of latent classes in the mixture Rasch model through simulations. The simulation study manipulated various class-distinction features (percentages of class-variant items, magnitudes, and patterns of item difficulty differences) and mixing proportions, assuming that a mixture Rasch model with two latent classes was the true model. Unlike previous studies that showed BIC's superiority to other indices, our findings from this study suggested that the four information criteria had differential performance depending on the percentage of class-variant items and the magnitude and pattern of item difficulty differences under a two-class structure. Furthermore, the present study revealed that AICC and SABIC generally performed as good as or better than their counterparts, AIC and BIC, respectively, for the class-class structure with a sample of 3,000.     

Detecting Differential Item Discrimination (DID) and the Consequences of Ignoring DID in Multilevel Item Response Models

Cross‐level invariance in a multilevel item response model can be investigated by testing whether the within‐level item discriminations are equal to the between‐level item discriminations. Testing the cross‐level invariance assumption is important to understand constructs in multilevel data. However, in most multilevel item response model applications, the cross‐level invariance is assumed without testing of the cross‐level invariance assumption. In this study, the detection methods of differential item discrimination (DID) over levels and the consequences of ignoring DID are illustrated and discussed with the use of multilevel item response models. Simulation results showed that the likelihood ratio test (LRT) performed well in detecting global DID at the test level when some portion of the items exhibited DID. At the item level, the Akaike information criterion (AIC), the sample‐size adjusted Bayesian information criterion (saBIC), LRT, and Wald test showed a satisfactory rejection rate (>.8) when some portion of the items exhibited DID and the items had lower intraclass correlations (or higher DID magnitudes). When DID was ignored, the accuracy of the item discrimination estimates and standard errors was mainly problematic. Implications of the findings and limitations are discussed.     

‘Love honey,hate honey bees’: reviving biophilia of elementary school students through environmental education program

The concept of emotional affinity and connection with nature using the term of ‘biophilia’ along with its counter-part ‘biophobia’ has been merely researched in the area of environmental education. In this study, it was hypothesized that children’s negative emotions (biophobia) such as fear towards insects can be changed into affinity (biophilia) through an environmental education program. One hundred and four third-grade students from an elementary school in Seoul, South Korea participated in the honey bee environmental education program, and their emotional changes were measured with Inclusion of Nature in Self and Connectedness to Nature Scale. The result after the program implementation showed that the participants’ affinity toward nature was significantly improved. This empirical study suggests that an environmental education programs on insects of which children initially feel scared can be effective in helping to overcome fear toward insects and nature, and to revive their innate biophilia. Especially, honey bees, one of the most crucial insect species providing priceless ecosystem services can be a good medium for environmental education program to promote children’s innate love towards nature. This study, to the authors’ knowledge, was the first research which attempted to link an insect-mediated environmental education program to children’s connectedness to nature with the biophilia–biophobia approach.     

1997年以来香港科技政策转向及其特征分析

以殖民时期港英政府科技政策的简要回顾为出发点,着重考察1997年以来香港科技政策新的发展趋向,并在此基础上分析香港科技政策演变的特征和面临的挑战.     

Exploring the relationships between students' academic motivation and social ability in online learning environments

This research explicates the construct of social ability and describes the relationship between students' academic motivation and social ability in online learning environments. Findings reveal perceived peers social presence, perceived written communication skills, perceived instructor social presence, comfort with sharing personal information, and social navigation as the five factors that define social ability. In addition, the multivariate multiple regression analyses indicate that different motivational constructs vary in their relationships with the multiple social ability factors. Intrinsic goal orientation is related to perceived peers social presence. Self-efficacy explains the variance of perceived instructor social presence and comfort with sharing personal information. Task value is associated with social navigation and both perceived peers and instructor social presence. Additional studies are needed to replicate the current findings and further explicate social ability in online learning, to continue to improve the social ability instrument, and to examine the value of other academic motivation beliefs in predicting social ability as well as that of social ability in predicting learning outcomes.     

基于高技术产业发展的香港制造业重建研究

本文通过对近10年来香港国际竞争力排名演变特征及动因进行分析,指出制造业的空心化和经济基础过于狭窄是导致其经济运行不稳定的主要原因。在此基础上,探讨了重建基于高技术产业发展为导向的香港制造业的必要性和可能性问题。     

Understanding users’ continuance intentions to use smart-connected sports products

The authors investigate the salient factors that influence users’ continuance intentions to use smart-connected sports products. Drawing on the theory of planned behavior (TPB), they propose that three major factors—attitude, social comparison as social influence, and perceived behavioral control—significantly influence users’ continuance intentions. Smart-connected sports product users (N = 236) participated in this study. Collected data were analyzed using Partial Least Squares (PLS) modeling. Results suggest two different attitudinal beliefs—technology-related (perceived usefulness) and fashion-related (perceived comfort) factors—of smart-connected sports products influence attitudes toward the products and that control-related factors (technical functionality and facilitating conditions) play a role in regulating users’ volitional behaviors from their intentions. The authors highlight user beliefs of smart-connected sports products based on TPB and propose a concrete, practical set of factors that practitioners might manipulate to facilitate users’ continuance intentions to use smart-connected sports products.     

A Cross-Cultural Study of the Self-Confidence of Counselors-in-Training

In this era of globalization, cross-cultural comparison studies could help counselor training programs enhance educational opportunities that are informative, supportive, and culturally responsive to students. Counselors-in-training in both the United States and South Korea were sampled in this study assessing self-esteem (individual and collective) and counselor activity self-efficacy (CA self-efficacy). Results indicated that American students endorsed higher levels of collective self-esteem and CA self-efficacy compared to Korean students. Age was positively correlated with CA self-efficacy in both the American and Korean samples. Additionally, the variable of supervision hours and internship experience was positively correlated with CA self-efficacy for American students, but showed no relationship with CA self-efficacy for Korea students. Implications for understanding the cultural differences of counseling-trainees’ self-confidence and the need for conducting cross-cultural comparison studies to provide insights about the training and development of trainees in cross-cultural settings are discussed.