Phases and patterns of group development in virtual learning teams

With the advancement of Internet communication technologies, distributed work groups have great potential for remote collaboration and use of collective knowledge. Adopting the Complex Adaptive System (CAS) perspective (McGrath, Arrow, & Berdhal, Personal Soc Psychol Rev 4 (2000) 95), which views virtual learning teams as an adaptive and self-organizing entity, this study examined group development processes of seven intact virtual learning teams over 12 weeks using the multiple case study design. Content analysis revealed seven temporal group development phases: orientation, scheduling, exploration, work and decision, progress check and evaluation, refinement and formatting, and termination. The development pattern of each virtual learning team could be described as either Linear Progression, a straight movement through those phases, or Adaptive Progression, a backward movement to a previous phase for adaptation before proceeding. We also identify the factors that caused each team to develop in one way or the other and conclude with the implications of conceptualizing virtual teams as a CAS.     

Family disruption and academic functioning in urban,black youth

The purpose of this study was to examine from an ecological perspective the relationships between multiple levels of family disruption and children's academic functioning in a sample of 390 urban, Black adolescents at age 14. Subjects in this cohort have been followed longitudinally since before their birth. Data from previous assessments at birth and age 7 years allowed for control of important correlates in this analyses. Examination of this unique sample, using multisource data collection procedures, provides important information about the many family disruptions among urban, low‐income families and the effects of these disruptions on academic outcomes. Results revealed several consistent findings, the most notable of which is that, when parents were married, adolescents demonstrated significantly higher grades, mediated through paternal involvement. Of all variables studied, the role of fathers in the lives of these adolescents was the most influential on academic outcomes. In this unique sample, even variables such as involvement with child protective services were not significantly related to outcomes after important control variables were factored into analyses. Results of this study have important implications for future research and for prevention and intervention efforts in urban, at‐risk samples. Emphasis is made for work in the school context, particularly for school psychologists. © 2011 Wiley Periodicals, Inc.     

The effects of captions on deaf students' content comprehension, cognitive load, and motivation in online learning

The authors examined the effects of captions on deaf students' content comprehension, cognitive load, and motivation in online learning. The participants in the study were 62 deaf adult students who had limited reading comprehension skills and used sign language as a first language. Participants were randomly assigned to either the control group or the experimental group. The independent variable was the presence of captions, and the dependent variables were content comprehension, cognitive load, and motivation. The study applied a posttest-only control group design. The results of the experiment indicated a significant difference (t = -2.16, p < .05) in content comprehension but no statistically significant difference in cognitive load and motivation between the two groups. These results led to suggestions for improvements in learning materials for deaf individuals.     

Characterization of anomalous movements of spherical living cells on a silicon dioxide glassy substrate

The random walk of spherical living cells on a silicon dioxide glassy substrate was studied experimentally and numerically. This random walk trajectory exhibited erratic dancing, which seemingly obeyed anomalous diffusion (i.e., Lévy-like walk) rather than normal diffusion. Moreover, the angular distribution (−π to π) of the cells'' trajectory followed a “U-shaped pattern” in comparison to the uniform distribution seen in the movements of negatively charged polystyrene microspheres. These effects could be attributable to the homeostasis-driven structural resilient character of cells and physical interactions derived from temporarily retained nonspecific binding due to weak forces between the cells and substrates. Our results provide new insights into the stochastic behavior of mesoscopic biological particles with respect to structural properties and physical interactions.     

“Gangnam Style” in Dhaka and inter-Asian refraction

This essay explores the political implications of the flash mob dance in Dhaka, Bangladesh performed in response to the 2012 global viral sensation of South Korean rapper PSY’s “Gangnam Style” music video. The global fame of “Gangnam Style” has much to do with its success online and in the U.S. popular music industry. It, however, also solicited suspicion from popular culture critics that the images of comical PSY worked successfully thanks to unchecked consumption of the racial stereotypes of Asian men. While recognizing these problems as more than valid, this essay simultaneously calls for a more transnational and inter-Asian understanding of the material to argue for a productive quality of PSY’s performance. Using “refraction” as a mode of thinking about inter-Asian circulation of pop culture, this essay considers the flash mob performed in Dhaka, Bangladesh as an important yet underexplored case study that shows different performative practices associated with “Gangnam Style” deeply rooted in historicity of colonialism and nationalism. The case study shows that the circulation of “Gangnam Style” materialized through a performance in Dhaka enlarged contemporary discourse among young urban Bangladeshi spectators around Bangladeshiness and its cultural identity. This complicated an easy assumption about “Gangnam Style” and its success in the U.S. mainstream pop culture, while simultaneously displacing the Bangladeshi cultural subjects from the immobile position of “the Other.”     

A new perspective on in vitro assessment method for evaluating quantum dot toxicity by using microfluidics technology

In this study, we demonstrate a new perspective on in vitro assessment method for evaluating quantum dot (QD) toxicity by using microfluidics technology. A new biomimetic approach, based on the flow exposure condition, was applied in order to characterize the cytotoxic potential of QD. In addition, the outcomes obtained from the flow exposure condition were compared to those of the static exposure condition. An in vitro cell array system was established that used an integrated multicompartmented microfluidic device to develop a sensitive flow exposure condition. QDs modified with cetyltrimethyl ammonium bromide∕trioctylphosphine oxide were used for the cytotoxicity assessment. The results suggested noticeable differences in the number of detached and deformed cells and the viability percentages between two different exposure conditions. The intracellular production of reactive oxygen species and release of cadmium were found to be the possible causes of QD-induced cytotoxicity, irrespective of the types of exposure condition. In contrast to the static exposure, the flow exposure apparently avoided the gravitational settling of particles and probably assisted in the homogeneous distribution of nanoparticles in the culture medium during exposure time. Moreover, the flow exposure condition resembled in vivo physiological conditions very closely, and thus, the flow exposure condition can offer potential advantages for nanotoxicity research.     

A Modified Comparative Fit Index for Factorial Invariance Studies

As a prerequisite for meaningful comparison of latent variables across multiple populations, measurement invariance or specifically factorial invariance has often been evaluated in social science research. Alongside with the changes in the model chi-square values, the comparative fit index (CFI; Bentler, 1990) is a widely used fit index for evaluating different stages of factorial invariance, including metric invariance (equal factor loadings), scalar invariance (equal intercepts), and strict invariance (equal unique factor variances). Although previous literature generally showed that the CFI performed well for single-group structural equation modeling analyses, its applicability to multiple group analyses such as factorial invariance studies has not been examined. In this study we argue that the commonly used default baseline model for the CFI might not be suitable for factorial invariance studies because (a) it is not nested within the scalar invariance model, and thus (b) the resulting CFI values might not be sensitive to the group differences in the measurement model. We therefore proposed a modified version of the CFI with an alternative (and less restrictive) baseline model that allows observed variables to be correlated. Monte Carlo simulation studies were conducted to evaluate the utility of this modified CFI across various conditions including varying degree of noninvariance and different factorial invariance models. Results showed that the modified CFI outperformed both the conventional CFI and the ΔCFI (Cheung & Rensvold, 2002) in terms of sensitivity to small and medium noninvariance.     

Making the Invisible Visible in Science Museums Through Augmented Reality Devices

Despite the potential of augmented reality (AR) in enabling students to construct new understanding, little is known about how the processes and interactions with the multimedia lead to increased learning. This study seeks to explore the affordances of an AR tool on learning that is focused on the science concept of magnets and magnetic fields. Seventy students in grades 5 through 7 participated in the study in a non- AR or AR condition. Findings showed that students in the AR condition interacted with the magnets significantly longer and demonstrated higher amounts of teamwork. In interviews, students identified five affordances of the AR on learning that are closely related to the literature on dynamic visualizations, such as the ability to visualize invisible phenomenon and scaffolds that focus attention on relevant information.