Analysis of a laminar-flow diffusional mixer for directed self-assembly of liposomes

The present work describes the operation and simulation of a microfluidic laminar-flow mixer. Diffusive mixing takes place between a core solution containing lipids in ethanol and a sheath solution containing aqueous buffer, leading to self assembly of liposomes. Present device architecture hydrodynamically focuses the lipid solution into a cylindrical core positioned at the center of a microfluidic channel of 125 × 125-μm² cross-section. Use of the device produces liposomes in the size range of 100–300 nm, with larger liposomes forming at greater ionic strength in the sheath solution and at lower lipid concentration in the core solution. Finite element simulations compute the concentration distributions of solutes at axial distances of greater than 100 channel widths. These simulations reduce computation time and enable computation at long axial distances by utilizing long hexahedral elements in the axial flow region and fine tetrahedral elements in the hydrodynamic focusing region. Present meshing technique is generally useful for simulation of long microfluidic channels and is fully implementable using comsol Multiphysics. Confocal microscopy provides experimental validation of the simulations using fluorescent solutions containing fluorescein or enhanced green fluorescent protein.     

Mentoring partnerships in a community technology centre: A constructionist approach for fostering equitable service learning

Mentoring programmes have gained increasing popularity in institutions of higher education to support undergraduates in community service or outreach efforts. Many of these programmes partner mentors with inner‐city youth, providing assistance in underserved communities while mentors gain experiences that connect theory and practice. Here we report on two years of fieldwork in a Community Technology Centre that created mentoring partnerships in which 36 liberal arts undergraduates engaged with local youth to design, create, and build technology projects involving graphics, video, music, and animation. We analysed over 200 field notes, which described their mentoring interactions over eight weeks and conducted exit interviews about their mentoring experiences. Our results indicate that mentors participated not just as more knowledgeable peers but also as facilitators, advisors, observers and, most importantly, as learners in this process. In the interviews, nearly all mentors reviewed assumptions about their own learning and mentoring, in addition to reflections about social issues. We discuss the importance of these findings for conceptualising mentoring as a partnership by creating more equitable interactions in service learning initiatives. We also address the role of constructionist activities in facilitating learning opportunities for both mentors and mentees.     

Using Web-Based Key Character and Classification Instruction for Teaching Undergraduate Students Insect Identification

The purpose of the study was to determine whether undergraduate students receiving web-based instruction based on traditional, key character, or classification instruction differed in their performance of insect identification tasks. All groups showed a significant improvement in insect identifications on pre- and post-two-dimensional picture specimen quizzes. The study also determined student performance on insect identification tasks was not as good as for family-level identification as compared to broader insect orders and arthropod classification identification tasks. Finally, students erred significantly more by misidentification than misspelling specimen names on prepared specimen quizzes. Results of this study support that short web-based insect identification exercises can improve insect identification performance. Also included is a discussion of how these results can be used in teaching and future research on biological identification.     

Preschoolers' Attention to Print During Shared Book Reading

Seventy-six children ages 3 to 5 were individually read two storybooks that had been specially formatted to contain salient printed words within the text, and illustrations and text on left or right-facing pages. The reader pointed to each word while reading to half of the children. After each book, children were asked to recognize elements of the illustrations and the specially formatted text elements from among a set of foils. Videotaped sessions were coded for the time children spent looking toward the pages with print versus illustrations. Analyses showed that the percentage of time looking at print was less than 2% in the no-pointing condition but increased with age. Pointing to the words increased print-looking time for all age groups and print target recognition for 4-year-olds. After controlling for receptive vocabulary, visual memory, and maturation associated with these scores, emergent orthography and letter-word identification predicted time looking at print and recognition of the print elements.     

Family and Reading in 41 Countries: Differences Across Cultures and Students

Family characteristics' links to literacy learning and their differences across macrosystems (economic and cultural contexts) were explored in multilevel analyses of the reading tests and questionnaire responses of 193,841 fifteen-year-olds across 41 countries. Students who had two parents, had higher family socioeconomic status (SES), were native born, had more books at home, had more cultural possessions at home, had more cultural communication at home, had no resident grandparents, or had fewer siblings (especially older ones) often had higher reading scores. However, country-level factors moderated these results. In richer countries, blended families (one parent and one stepparent) and cultural communication at home were more strongly linked to reading scores. In egalitarian cultures, SES had a stronger link to reading scores. In collectivist cultures, single parent status, SES, and resident grandparents had weaker links to reading scores. Thus, macrosystems are crucial to consider for understanding how family characteristics might impact reading achievement.     

Library Space Redesign and Student Computing

Academic libraries are spending considerable time and study on redesigning spaces. The use of technology is often an important part of these redesigned spaces. The space redesign goals at F.D. Bluford Library focus on creating open, activity-promoting, colorful spaces that are designed to be attractive to students. The goals also focus on implementing hybrid spaces that allow students to work alone or in groups, with support for mobile technologies like laptops or tablets. The space redesign goals focus on upgrading the quality of desktops available but reducing the number of desktops. This study examines the question “Does our library renovation significantly change computer use in the redesigned area?” Key findings include that, in defiance of expectations, there is no significant decrease in desktop usage despite the decreased number of computers. However, findings show there is a significant difference in tablet use, despite tablet-friendly spaces and charging options. Surprisingly, our students use fewer tablets. Laptop usage shows no significant difference. In summary, our research shows desktop computing—especially high-quality desktop computing—appears to still have a role in academic libraries even in the mobile technology age.     

Immigrant students in Denmark: why are they disadvantaged in civic learning?

Abstract

Although native family students often learn more than immigrant family students in school (e.g. civics), scholars have not systematically demonstrated the mechanisms through which native family students outperform immigrant family students. The Opportunity-Propensity framework guides this study. We examine the link between students’ immigrant status and civic knowledge, with antecedent factors (socioeconomic status [SES] and language spoken at home), opportunity factors (civic learning at school, civic participation at school, and political discussion), and propensity factors (perceived open classroom climate and student-teacher relationship). Two-level path analysis of the responses to the International Civic and Citizenship Education Study (ICCS) 2016 by 6254 eighth graders in Denmark showed that the civic knowledge of native family students exceeded that of immigrant family students, mediated by their own and schoolmates’ higher family SES. Meanwhile, immigrant family students had more political discussions, which are linked to better civic knowledge.     

Applying questioning or reading strategy to review technology enhanced coedited notes of elementary school students

The authors examined whether applying questioning review better enhances elementary level students' learning from technology-enhanced coediting-based note taking than does traditional reading review. A nonequivalent comparison group quasi-experimental design was implemented and replicated on four independent units. Two sixth grade elementary classes (66 students) participated in this study and were arranged into coediting notes with questioning review and coediting notes with reading review conditions respectively. The comparisons of student notes and achievement tests do not reveal that the questioning review group achieves better performance than does the reading review group. Considerations associated with technology enhanced coediting notes and questions are discussed based on the results.